• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PRELOAD APPLIANCE AND DYNAMIC BRAKING OF ENERGY STAGES FOR MULTILEVEL INVERTER. Dynamic braking and precharging circuits (200) for multilevel inverter power stages (100) with a shared resistor connected to charge a DC bus capacitor (C) with current from the rectifier circuit (120) in a first mode of operation and connected in parallel with the capacitor (C) to dissipate energy in a dynamic braking mode
    公开号:BR102014008470B1
    申请号:R102014008470-3
    申请日:2014-04-08
    公开日:2021-05-18
    发明作者:Jingbo Liu；Thomas Nondahl
    申请人:Rockwell Automation Technologies, Inc；
    IPC主号:
    专利说明:

    BACKGROUND
    [001] Power converters are used to convert incoming electrical energy from one form to another to drive a load. One form of energy conversion system is a motor drive, which can be employed for variable speed operation of an electric motor load. Multilevel inverters such as Cascade H Bridge (CHB) inverters are sometimes employed in motor drives and other energy conversion systems to generate and provide high voltage drive signals, with individual power cells or power stages being connected in series. Each stage provides a separate DC (direct current) source and is driven by switch signals to generate positive or negative output voltage, with the series combination of multiple stage outputs providing multi-level inverter output capability to drive the load at speeds and variable torques. SUMMARY
    [002] Various aspects of the present disclosure are now summarized to facilitate a basic understanding of the disclosure, in that this summary is not an extensive, overview of the disclosure, and is not intended to identify certain elements of the disclosure, nor to delineate the scope of the disclosure. same. Rather, the main purpose of this summary is to present various concepts of revelation in simplified form before the more detailed description that follows. The present disclosure provides apparatus and techniques for precharging single-stage DC bus capacitors or power cells of individual multi-level inverters, as well as for implementing dynamic braking within the power stage using a shared resistor.
    [003] In accordance with one or more aspects of the disclosure, a power conversion system is provided that includes a multi-level inverter with one or more inverter legs, each having a plurality of power stages individually providing multiple voltage levels of outputs, as well as a conversion system controller providing switching control signals to set the individual output levels of the power stages. The individual power stages include a DC bus circuit provided with DC voltage by a rectifier, as well as a switching circuit that provides a power stage output voltage at one of a plurality of distinct levels. A pre-charge and dynamic braking circuit is provided within the individual power stages, including a resistor connected between the rectifier and the switching circuit. The dynamic pre-charge and braking circuit operates in a first mode to drive current from the rectifier through the resistor to charge the DC bus capacitor, as well as in a second mode to bypass the resistor and allow current to flow from the rectifier to the circuit. switch to normal operation. In a third mode of operation, the pre-charge and dynamic braking circuit connects the resistor in parallel with a capacitor to facilitate dynamic braking operation.
    [004] In certain embodiments, the pre-charge and dynamic braking circuit includes a first switch coupled in a branch of the DC circuit between the rectifier and the switching circuit, as well as a first diode coupled in parallel with the first switch. For normal or dynamic braking operation, the first switch is closed or otherwise made conductive to bypass the resistor, and the switches are opened or made non-conductive so that pre-charge current from the rectifier flows through the resistor to charge the capacitor in a precharge mode of operation. In various embodiments, furthermore, a second switch is coupled between another branch of the DC circuit and the resistor, with the second switch being open or non-conductive during normal and pre-load operation, and the second switch is closed or modulated by pulse width during dynamic braking for selective connection of the resistor in parallel with the DC bus capacitor. In certain implementations, a power stage controller provides control signals to the first and second switches to set the mode of operation in accordance with the DC bus voltage of the power stage, such as when setting the circuit for a first or mode. of precharge operation if the DC bus voltage is less than a first threshold (eg lower), operating in a second or normal mode with the resistor not carrying any current when the DC bus voltage is above the first threshold and below a second threshold (eg higher), and operating in a third or dynamic braking mode when the DC bus voltage exceeds the second threshold.
    [005] Non-transient computer readable media and methods are provided with computer executable instructions for operating individual power stages of a multilevel inverter. These techniques include precharging a power stage DC bus capacitance through a resistor if the DC bus voltage is less than a first threshold, and connecting the resistor in parallel with the DC bus capacitance if the voltage is greater. than a second threshold. In certain embodiments, the resistor is bypassed to allow current to flow between the rectifier and the power stage switching circuit if the DC bus voltage is between the first and second threshold values. BRIEF DESCRIPTION OF THE DRAWINGS
    [006] The following description and drawings set out in detail certain illustrative implementations of the disclosure which are indicative of various exemplary ways in which the various principles of the disclosure may be carried out. The illustrated examples, however, are not exhaustive of the many possible modalities of revelation. Other goals, advantages and unprecedented features of the disclosure will be exposed in the detailed description below when considered in combination with the drawings, in which:
    [007] Figure 1 is a schematic diagram illustrating a 13-level CHB inverter-based three-phase motor drive power conversion system with three inverter legs, each having six power stages or power cells connected in series between a neutral point and a motor load phase;
    [008] Figure 2 is a schematic diagram illustrating an exemplary power stage in the power converter of Figure 1 having a preload and dynamic braking circuit using a shared resistor in accordance with one or more aspects of the present disclosure;
    [009] Figure 3 is a flowchart illustrating an exemplary method for operating individual power stages in a multilevel inverter in accordance with additional aspects of the present disclosure;
    [010] Figure 4 is a schematic diagram illustrating operation of the power stage of Figure 2 during a first mode for controlled pre-charging of a DC bus capacitor by means of a resistor in a first mode of operation;
    [011] Figure 5 is a schematic diagram showing operation of the power stage of Figure 2 during normal operation; and
    [012] Figure 6 is a schematic diagram illustrating dynamic braking operation of the power stage of Figure 2 with the resistor connected in parallel across the DC bus capacitor. DETAILED DESCRIPTION
    [013] Referring now to the figures, various embodiments or implementations are described below in combination with the drawings, in which like reference numerals are used to refer to like elements throughout, and in which the various features are not , necessarily drawn to scale. Multilevel inverter power stage architectures are presented in which pre-charge and dynamic braking functions are achieved using a single shared resistor with switching circuitry in an intermediate DC bus circuit to selectively connect the resistor to control charging of a DC bus capacitance or to connect the resistor in parallel with the DC bus capacitance to facilitate dissipation of counteracting electromotive force from a driven motor or other load, while further facilitating normal operation with the bypass resistor. Dynamic braking and preload functionality is a desirable combination of features for cascaded H-bridge and other multi-level power converter architectures, and the present disclosure provides simple and effective designs to implement both functions with localized circuitry within the individual energy stages forming the structures of multiple cascaded or series connected cells. Dynamic braking apparatus can be used to selectively decrease a motor load being driven by an energy converter, and the present disclosure provides selective switching to connect an impedance to dissipate energy returning from the motor load as the motor decelerates.
    [014] Pre-charging is also performed using the same impedance to charge the DC bus capacitor, for example at start-up or after power interruption, where the DC bus voltage drops below a nominal level. Circuitry within the individual power stages activates when the DC bus voltage is below a predetermined threshold value to charge the capacitor at a controlled rate by driving current from the power stage rectifier or other local DC source through the impedance to limit the drive current to the capacitor, thus protecting the capacitor and semiconductor charging devices from overcurrent conditions. In the illustrated modalities, for example, the shared resistor is dimensioned in order to reduce the current increase under load to a manageable level, and also to facilitate dynamic braking operation. The circuitry thus represents a significant advance over conventional multilevel inverters by providing these two functions with a minimal number of circuit elements. The techniques of the present disclosure, furthermore, find utility in association with low voltage as well as medium or high voltage power converter applications involving any number of cascaded power stages using included circuitry with a shared resistor sized for the energy levels associated with the cell or individual energy stage.
    [015] An exemplary multilevel inverter motor drive power conversion system 10 is shown in Figure 1, in which the individual power cells or power stages 100 incorporate dynamic braking and precharging circuitry employing a resistor shared. The power converter 10 includes a 40 three-phase multilevel inverter with the power stages connected in series 100-1, 100-2, 100-3, 100-4, 100-5, 100-6 for each of the three sections or legs. of inverter 102U, 102V, and 102W associated with the corresponding motor phases U, V, and W of a motor load 50. While the concepts of the present disclosure are shown in the context of a multi-phase multilevel inverter driving a motor load, other embodiments are possible in which other forms of load 50 are driven, including without limitation single-phase AC (alternating current) loads, wherein, the present disclosure, is not limited to multi-phase motor drive type power converters. In certain embodiments, in addition, the individual power stages 100 include an H 40 bridge switch or inverter circuit with switching devices (eg Q1-Q4 with associated diodes D11-D14 in Figure 2 below), although any suitable form of output switching circuit 40 can be provided in the individual power stages 100 with two or more switches forming a switching circuit to generate a power stage output having one of two or more possible levels according to the signals. control switches 62 provided by a control component or inverter controller 64 of a power converter controller 60.
    [016] The example in figure 1 is a 13-level multi-phase 40 inverter with six power cells or 100 power stages for each of the three motor load phases U, V and W (eg 100-U1 , 100-U2, 100-U3, 100-U4, 100-U5 and 100-U6 forming a first 102U inverter leg for the U phase; 100-V1, 100-V2, 100-V3, 100-V4, 100- V5 and 100-V6 forming a second 102V inverter leg for phase V; and stages 100-W1, 100-W2, 100-W3, 100-W4, 100-W5 and 100-W6 forming a third 102W inverter leg for phase W). Each of the inverter legs 102 in this example, moreover, is connected between an energy converter neutral point N and the corresponding motor load U, V or W. The various aspects of the present disclosure can be implemented in association with power systems. single-phase or multi-phase multilevel inverter type power conversion having any integer “N” of power stages 100, where N is greater than one. Furthermore, although the illustrated embodiments utilize the cascaded H Bridge stages 100 to form the multilevel inverter legs 102 for each output phase of the motor drive system 10, other types and shapes of the power stages 100 can be used, such as a stage 100 with a switching circuit having more or less than four switching devices, in which the broader aspects of the present disclosure are not limited to the Bridge H 100 power cells shown in the illustrated embodiments. For example, embodiments are possible in which individual cells 100 can include as little as two switching devices or any integer number of switches equal to or greater than two.
    [017] The power converter 10 is provided with multi-phase AC input power from a phase shift transformer 30 having a multi-phase primary 32 (a delta configuration in the illustrated mode) receiving three-phase power from a power source AC 20. Transformer 30 includes 18 three-phase 34 secondaries, with six sets of three-phase secondaries configured with three deltas 34, each set being in a different phase relationship. Although the primary 32 and secondary 34 are configured as delta windings in the illustrated example, “Y” connected primary and/or secondary windings or other winding configurations can alternatively be used. Furthermore, although the transformer has the three-phase primary and secondary windings 32, 34, other single-phase or multi-phase implementations can be used, and the secondaries or sets thereof need not be phase shifted. Each three-phase secondary 34 in the example of Figure 1 is coupled to supply AC power to drive a three-phase rectifier 120 from a corresponding 100 power stage of the 40 three-phase multilevel inverter. Inverter 40 in this example is a 13-level inverter with six power stages H-Bridges cascaded 100-U1 to 100-U6 having outputs 104-U1 to 104-U6 connected in series with each other (cascaded) between neutral N and a first winding U of the three-phase motor load 50. Similarly , power stages 100-V1 to 100-V6 provide the voltage outputs connected in series 104-V1 to 104-V6 between neutral N and second winding V, and power stages 100-W1 to 100-W6 provide the voltage outputs connected in series 104-W1 to 104-W6 between neutral N and the third winding W of motor 50.
    [018] In operation, the motor drive controller 60 provides the 62U control signals for the power stages 100-U1 to 100-U6 associated with the first motor winding U, and also provides the 62V control signals for the stages 100-V1 to 100-V6 power supply and the 62W control signals for the 100-W1 to 100-W6 power stages. Although the inverter 40 shown in Figure 1 is a multi-phase unit providing output power to phases U, V and W to drive a three-phase motor 50, the concepts of the present disclosure are also applicable to single-phase converters, e.g. three-phase to single-phase receiving a three-phase input from source 20, with a single series-connected group of cells 100 providing power to a single-phase motor or other single-phase output load. In addition, other multi-phase outputs can be provided using corresponding series-connected groups of power stages 100 having more than three phases or inverter legs 102.
    [019] Motor drive controller 60 and its component 64 may be implemented using any suitable hardware, software or firmware executed by processor, or combinations thereof, wherein an exemplary embodiment of controller 60 includes one or more such processing elements such as microprocessors, microcontrollers, FPGAs, DSPs, programmable logic, etc., along with electronic memory, program memory and signal conditioning driver circuitry, with the programmed processing element(s) s) or otherwise configured to generate the inverter switching control signals 62 suitable for operating the switching devices of the power stages 100, as well as for performing other motor drive operational tasks to drive the load 50 .
    [020] Figure 2 illustrates a possible implementation of a Bridge H 100 power stage that can be reproduced to form the cascaded power stages of single-phase or multi-phase multilevel inverters 40 such as the one shown in figure 1. The power stage in Fig. 2 includes a three-phase AC input 108 with input terminals 108A, 108B and 108C connectable to receive AC input power, in this case three-phase power from an AC source such as a secondary winding 34 of the transformer 30 in Fig. 1. Other implementations are possible in which individual power stages or cells 100 receive single-phase AC input power, or where individual power stages 100 receive DC input power from an external DC source (not shown). In the illustrated example, AC input power is supplied by cell input 108 to a rectifier circuit 120 having built-in rectifier diodes D1-D6 forming a three-phase rectifier 120 that receives three-phase AC power from the corresponding transformer secondary 34 and provides DC output power. at output terminals 121 (+) and 122 (-) connected to a DC bus circuit 130. In this example, a passive rectifier 120 is used, but active rectifier circuits or other forms of rectifier can be used, having an AC input of single-phase or multi-phase.
    [021] The power stage 100 in Figure 2 also includes a DC link or bus circuit 130 and an output switching circuit 140 (eg H Bridge inverter) providing an output voltage Vout at a controlled level of a plurality of distinct output voltage levels for a power cell output 104 having first and second output terminals 104A and 104B. In certain embodiments, bypass circuitry can be provided on the individual power stages 100 to bypass output 104 (not shown). The DC bus circuit 130 includes a DC bus capacitor C connected between a first or upper circuit branch extending between the positive output node 121 of the rectifier 120 and a positive input node 131 connected to the output switching circuit. 140, and a second or lower circuit branch extending between the negative output node 122 of the rectifier 120 and the negative input node 132 of the output switching circuit 140. As further described below, in addition, a circuit of dynamic preload and braking 200 is provided between rectifier 120 and output switching circuit 140.
    [022] In normal operation, rectifier 120 supplies DC power through the DC bus capacitor C. The DC link circuit 130, in turn, provides an input to an H 140 Bridge inverter formed by the four Q1-Q4 switching devices configured in an “H” bridge circuit. Although the illustrated power stage 100 operates on the basis of DC power supplied by an internal rectifier circuit 120 driven by an AC input from the corresponding transformer secondary 34, any suitable form of a DC input can be provided to the power stages 100 of in accordance with the present disclosure, and the power stages 100 may, but need not, include the rectification circuitry 120. Furthermore, any suitable switching circuit configuration may be used in the output switching circuits 140 (e.g. , inverter) of the individual stages 100 having at least two Q switching devices configured to selectively supply voltage at the output of stage 104 of at least two distinct levels. In addition, any suitable type of Q switching devices can be used on the 100 power stages, including, without limitation, semiconductor based switches such as insulated gate bipolar transistors (IGBTs), silicon controlled rectifiers (SCRs), thyristors. port shutdown (GTOs), integrated port switched thyristors (IGCTs), etc.
    [023] The illustrated four-switch Bridge H output switching circuit 140 advantageously allows selective switching control signal generation by controller 60 to provide at least two distinct voltage levels at output 104 in a controlled mode. For example, an output voltage Vout is provided at output terminals 104A and 104B of a positive DC level substantially equal to the DC bus voltage across capacitor C (eg +VDC) when switching devices Q1 and Q4 are connected. (conductive) while the other Q2 and Q3 devices are off (non-conductive). Conversely, a negative output voltage level Vout is provided when Q2 and Q3 are on while Q1 and Q4 are off (eg -VDC). This setting also allows for a distinct third output voltage level of approximately zero volts when turning on Q1 and Q3 while keeping Q2 and Q4 off (or alternatively when turning on Q2 and Q4 while keeping Q1 and Q3 off). In this way, the exemplary H-Bridge power stage 100 advantageously allows selection of two or more distinct output voltages, and the cascaded configuration of six such stages (eg, Figure 1) allows selective switching control signal generation by the inverter control component 64 to implement 13 different voltage levels (line to neutral) for application to the corresponding motor phase U, V or W. This, in turn, allows for 25 different line-to-line voltage levels. It is noted that another possible switching circuitry can be used to implement a two, three, or K selectable output levels for the individual stages 100, where K is any positive integer greater than 1. Any suitable logic or circuitry in the motor drive controller 60 can be used to supply the inverter switching control signals 62 to a given power stage 100, such as carrier-based switching circuitry and/or digital logic implementing the switching control signals pulse width modulated 62. In addition, controller 60 may include signal level amplification and/or driver circuitry (not shown) to provide adequate drive voltage and/or sufficient current levels to selectively drive the devices. Q1-Q4 switching devices, for example, such as comparators, carrier wave generators or logic drivers and digital signals.
    [024] As further shown in Figure 2, the individual power stages 100 also include a dual-function dynamic pre-charge and braking circuit 200 that can be connected anywhere in the DC path between rectifier 120 (or other input CC) and the output switching circuit 140. In the illustrated example the dynamic pre-charge and braking circuit 200 is configured between the rectifier 120 and the DC bus capacitance C, however other implementations are possible. In accordance with the present disclosure, furthermore, the dynamic pre-charging and braking circuit 200 advantageously employs a single shared resistor 206 operable for both controlled pre-charging of the DC link capacitor voltage and for dynamic braking operation. Furthermore, first and second switches 202 and 210 are provided in circuit 200 for selective connection of resistor 206 for these two purposes. Furthermore, a pre-charge and dynamic braking control circuit 220 is provided within each power stage 100 to control the operation of power stage 100 in one of three distinct modes, as summarized in the table shown in figure 2 Specifically, the controller 220 selectively changes the switching states of the pre-charge and dynamic braking circuit 200 to implement a first mode to precharge the DC link capacitor C, as well as to implement a normal and third operating mode. mode for dynamic braking. In certain embodiments, furthermore, controller 220 selectively sets the mode of operation at least partially in accordance with the DC bus voltage in circuit 130. For example, as seen in Figure 2, controller 220 may receive one or more signals feedback loops indicative of the voltage across the DC bus capacitor C (VCC). Any suitable hardware, firmware run by processor, software run by processor, logic circuitry, FPGA, etc. can be used to build the preload and dynamic brake controller 220, and any suitable feedback signal or signals can be used by the controller 220 to selectively establish the mode of operation of the power stage 100 as described in this document.
    [025] As seen in the table in Figure 2, at any time, the exemplary dynamic brake and preload controller 220 operates the power stage 100 in accordance with the detected DC bus voltage of intermediate DC circuit 130, and selectively places the 200 preload and dynamic braking circuit into one of three distinct operating modes by comparing bus voltage with first and second thresholds. Other forms of operating mode switching may be based on various implementations, in whole or in part, on one or more other operating conditions of the motor drive 10 or power stage 100 thereof. In the illustrated example, circuit 200 includes a resistor 206 coupled between rectifier 120 and output switching circuit 140, with controller 220 operating circuit 200 in a first mode of operation (pre-charge) to drive current from rectifier 120 through resistor 206 to capacitor C. In a second (normal) mode of operation, controller 220 operates circuit 200 to bypass resistor 206 thus allowing current to flow directly from rectifier 120 to switching circuit 140. Dynamic braking is achieved in a third mode of operation by connecting resistor 206 in parallel with capacitor C.
    [026] As seen in Figure 2, the first switch 202 is coupled to the first branch of the DC bus circuit between nodes 121 and 131, and operates in accordance with a first control signal 222 coming from controller 220 in a first state (open or non-conductive) to prevent current from flowing directly through the switch 202 between the rectifier 120 and the switching circuit 140. The first switching device 202 is also operable in a second state (closed or conductive) to allow current to flow through the switch 202 according to the control signal 222. Any suitable switching device 202 can be used, such as a contactor, relay or a semiconductor based switching device (eg IGBT, SCR, GTO, IGCT, etc. .), wherein the switching device 202 is preferably sized to accommodate the maximum current flow required in normal operation. Although the embodiment of Figure 2 provides the first switching device 202 on the upper or positive DC circuit branch 121, 131, other embodiments are possible in which the first switch 202 is provided alternatively on the lower DC circuit branch between nodes 122 and 132 As shown, furthermore, a diode 204 is connected across the switch 202, with the anode terminal connected to the output switching circuit node 131 and the cathode connected to the output node 121 of the rectifier 120. The diode 204 allows flow of regenerative current from the output switching circuit 140 to the node 121, for example during dynamic braking operation, but prevents or blocks forward current flow from the node 121 to the output switching circuit 140 when the switching device 202 is open or non-conductive.
    [027] Resistor 206 and a second diode 208 are connected in a circuit branch in parallel with the contacts of the first switching device 202, with resistor 206 being connected between node 121 and an internal node 209, with the anode of second diode 208 being connected to node 209 and the cathode being connected to node 131 as shown. Furthermore, a second switching device 210 is coupled between the second branch of the DC circuit at nodes 122 and 132 and the first internal node 209. The second switch 210 operates in accordance with a second control signal 224 from the pre-controller. -load and dynamic braking 220, and can be any suitable type of switching device, including without limitation a contactor, relay, or a semiconductor based switching device (eg, IGBT, SCR, GTO, IGCT, etc.) . Controller 220 includes any suitable logic and conditioning circuitry and/or signal drivers to provide control signals 222 and 224 to properly operate first and second switching devices 202 and 210 in accordance with operation and functionality. described in this document.
    [028] Referring also to figures 3-6, figure 3 illustrates an exemplary process or method 300 for operating an energy conversion system, which can be implemented using the pre-charge and dynamic braking controller 220 of the three-mode operation of the individual energy stages 104 thereof in accordance with various aspects of the present disclosure. Various aspects of the present disclosure additionally provide non-transient computer-readable media, such as an electronic memory operatively associated with controller 220, which include computer-executable instructions for performing the described methods, including the illustrated method 300 of Figure 3. While the method 300 is illustrated and described below in the form of a series of procedures or events, it will be appreciated that the various methods of disclosure are not limited by the illustrated ordering of such procedures or events. In this regard, except as specifically provided below, some procedures or events may occur in a different order and/or concurrently with other procedures or events than those illustrated and described herein in accordance with the disclosure. It is further noted that not all of the illustrated steps are necessarily required to implement a process or method in accordance with the present disclosure, and one or more such procedures may be combined. The illustrated method 300 and other methods of the disclosure may be implemented in hardware, processor-executed software, or combinations thereof, such as in the exemplary controller 220 described herein, and may be incorporated in the form of computer-executable instructions stored on a medium. non-transient tangible computer readable, such as in a memory operationally associated with controller 220 in one example.
    [029] The illustrated process 300 starts at 302 with application of power to the conversion system 10. As mentioned above, the preload resources can be employed by initially turning on the system 10 and/or by restarting power after a temporary interruption. A determination is made by controller 220 at 304 such as to check whether the DC link voltage is less than a first threshold (pre-charge) THPC. In one possible implementation, the THPC precharge threshold can be set at or near the nominal DC bus voltage associated with normal operation of power stage 100. If the DC bus voltage is equal to or greater than the first threshold ( NO at 304) the process 300 continues to 308 as described below.
    [030] Referring also to figure 4, if the bus voltage is less than the THPC threshold (SIM at 304 in figure 3), controller 220 switches to a first mode of operation at 306 to precharge the capacitor. bus C. As shown in Figure 4, controller 220 provides first control signal 222 in order to open first switch 202 (preload) and provides second control signal 224 to keep second switch 210 off (not conductive). As seen in Figure 4, current from rectifier 120 in this first precharge mode flows from node 121 through resistor 206 and diode 208 to node 131, and then through DC link capacitor C to the DC circuit branch. lower at node 132 to return to the negative rectifier terminal at node 122. For this operation, resistor 206 has a resistance value selected or designed according to the capacitance of the DC-link capacitor C to control the capacitor charging time C. In this regard, resistor resistance 206 sets the limit for the drive current, particularly for a fully discharged C-bus capacitor, thus protecting semiconductor devices (eg, passive rectifier diodes and/or active rectifier switches) from the rectifier 120 against overcurrent conditions, and also protects the C capacitor against high drive currents. As seen in Figure 3, furthermore, process 300 returns to reassess the DC bus voltage level against the THPC threshold and continues the pre-charge operation at 304, 306 until the DC bus voltage is at the THPC threshold level.
    [031] When the DC bus voltage is equal to or above the first threshold level THPC (NOT in 304), process 300 in figure 3 proceeds to 308 where a determination is made (for example, by controller 220) such as to verify if the DC bus voltage exceeds a second threshold (dynamic braking) THDB, which is greater than the first threshold THPC. The second THDB threshold can be set to any desired level suitable for activating dynamic braking in the cell or power stage 100, such as about 5% - 10% above the nominal DC bus voltage level in a non-limiting example. If the DC bus voltage is between the first and second thresholds (NOT at 308), controller 220 operates in a second or normal mode at 310, with control signals 222 and 224 keeping the first switch 202 in the closed or on state (eg, conductive) and the second switch 210 in an open/off state (eg, non-conductive). This operation is further illustrated in Figure 5, where the DC current flows from the positive rectifier node 121 through the first closed switch 202 to the upper input node 131 of the output switching circuit 140, thus maintaining the DC link voltage across the capacitor C and enabling switching operation of switching circuit 140 in accordance with switching control signals 62 from power converter controller 60 (figure 1 above).
    [032] Returning again to Fig. 3, this normal mode operation continues at 304, 308, and 310 as long as the DC bus voltage is between the first and second thresholds. If, however, the DC bus voltage exceeds the second (upper) threshold THDB (YES in 308), process 300 proceeds to 312 with controller 220 entering a third mode (dynamic braking). This dynamic braking operation is further illustrated in Figure 6, with controller 220 holding first switch 202 in the closed or conductive state via control signal 222, and selectively closing (making conductive) second switch 210 via control signal 224. In certain embodiments, controller 220 may simply close switch 210 during the third mode of operation (dynamic braking). In other possible embodiments, in addition, controller 220 may provide control signal 224 in order to pulse width modulate switch 210. In some implementations, for example, the pulse width modulation operation of control signal 224 it can be controlled at least in part according to the DC bus voltage level, for example, with the controller 220 increasing the pulse width for larger DC bus voltage excursions above the THDB threshold. For such pulse-width modulated implementations, furthermore, any suitable switching frequency can be used when controlling the operation of the second switch 210 via control signal 224. As seen in Figure 6, furthermore, the operation of the controller 220 in the dynamic braking mode provides a circuit path through resistor 206 to drive current from output switching circuit node 131 back through switch 202 closed (and/or through blocking diode 204), and then through the resistor. 206 and switch 210.
    [033] Thus, operation of controller 220 in dynamic braking mode provides an impedance via resistor 206 to dissipate excess back-flowing energy from output switching circuit 140. In this aspect, the resistance value of shared resistor 206 can be set in accordance with a desired braking impedance value, in addition to the aforementioned drive current limiting function performed by resistor 206 in the precharge operating mode. Resistor 206 determines the braking torque, and thus the rate of deceleration of a driven motor load 50, and the duty cycle of pulse-width modulated tap changer 210 determines the energy rating of the braking resistor. In certain non-limiting embodiments, for example, resistor 206 can be set to approximately 5Q - 10Q.
    [034] As seen in Figure 3, in addition, process 300 returns to re-evaluate the DC bus voltage at 304 and 308 as described above, thus implementing three-mode operation of the power cell 100 to pre-charge selectively the C-bus capacitor, operating in normal mode and/or providing dynamic braking.
    [035] The foregoing examples are merely illustrative of several possible modalities of various aspects of the present disclosure, in which equivalent changes and/or modifications will occur to those skilled in the art upon reading and understanding this descriptive report and the attached drawings. With particular reference to the various functions performed by the components described above (assemblies, devices, systems, circuits and the like), the terms (including a reference to a "feature") used to describe such components are intended to correspond, unless otherwise indicated, to any component, such as hardware, software executed by the processor, or combinations thereof, which performs the specified function of the described component (i.e., which is functionally equivalent), even if not structurally equivalent to the disclosed structure that performs the function in the illustrated implementations of the disclosure. Furthermore, although a particular feature of the disclosure may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. . Also, to the extent that the terms "including", "includes", "having", "has", "with", or variants thereof are used in the detailed description and/or in the claims, such terms are intended to be inclusive in a way similar to the term “understanding”.
    [036] List of components:
    权利要求:
    Claims (7)
    [0001]
    1. A power conversion system (10), comprising: a multi-level inverter (40) including at least one inverter leg (102) comprising a plurality of power stages (100), the individual power stages (100) comprising : a DC bus circuit (130) with a first branch of a DC circuit (121, 131) and a second branch of a DC circuit (122, 132), a rectifier circuit (120) providing a DC voltage for the DC bus circuit (130), an output (104), and a switching circuit (140) operable in accordance with switching control signals (62) to provide an output voltage at the output (104) at one of a plurality of voltage levels. outputs, the energy conversion system (10) characterized in that it additionally comprises: a pre-charge and dynamic braking circuit (200) with a resistor (206) connected between the rectifier circuit (120) and the circuit switching (140), the pre-charge and dynamic braking circuit (200) operat ive in a first mode of operation (pre-charge) to conduct current from the rectifier circuit (120) through the resistor (206) to charge a capacitor (C) of the DC bus circuit (130) in a second mode of operation (normal) to bypass the resistor (206) and allow current to flow from the rectifier circuit (120) to the switching circuit (140), and in a third mode of operation (dynamic braking) to connect the resistor (206) in parallel with the capacitor (C) of the DC bus circuit (130), the outputs (104) of the plurality of power stages of each of the at least one inverter legs (102) being coupled in series with each other, wherein the output (104) of a last power stage (100) of each of the at least one inverter legs (102) provides an output for driving a load (50); and a controller (60) operative to provide the switching control signals (62) to set the individual output voltage levels of the power stages (100) of the multi-level inverter (40), wherein the pre-charge and Individual dynamic braking (200) operate in the first operating mode if a DC bus voltage of the corresponding DC bus circuit (130) is less than a first threshold value (THPC), in the third operating mode if the DC bus voltage is greater than a second threshold value (THDB), and in the second operating mode (normal) if the DC bus voltage is between the first and second threshold values (THPC, THDB), the second threshold value (THDB) being greater than the first threshold value (THPC).
    [0002]
    2. Power conversion system (10), according to claim 1, characterized by the fact that the pre-load and dynamic braking circuit (200) of the individual power stages (100) comprises: a first switching device ( 202) coupled to the first branch circuit (121, 131) of the DC bus circuit (130) between the rectifier (120) and the switching circuit (140), the first switching device (202) operative in accordance with a first control signal (222) in a first state (open) to prevent current from flowing directly through the first switching device (202) between the rectifier (120) and the switching circuit (140), and in a second state (closed ) to allow current to flow through the first switching device (202); a first diode (204) coupled in parallel with the first switching device (202), with a cathode connected to the rectifier (120) and an anode connected to the switching circuit (140); a second diode (208) coupled in series with the resistor (206) in a circuit branch parallel to the first switching device (202), the second diode (208) having an anode connected to the resistor (206) and a cathode connected to the switching circuit (140); and a power stage controller (220) providing the first control signal (222) to selectively place the first switching device (202) into the first state in the first mode of operation, and to place the first switching device (202) in the second state in the second and third modes of operation.
    [0003]
    3. Power conversion system (10) according to claim 2, characterized by the fact that the pre-load and dynamic braking circuit (200) of the individual power stages (100) comprises: a second switching device ( 210) coupled between the second DC circuit branch (122, 132) and a first internal node (209) joining the second diode (208) and the resistor (206), the second switching device (210) operative in accordance with a second control signal (224) in a first state (open) to prevent current from flowing between the first internal node (209) and the second DC circuit branch (122, 132), and in a second state (closed) to allow that current flows between the first internal node (209) and the second DC circuit branch (122, 132); wherein the power stage controller (220) provides the second control signal (224) for selectively placing the second switching device (210) in the first state in the first and second modes of operation, and for placing the second switching device (210) in the second state for at least a portion of a time during which the preload and dynamic braking circuit (200) is in the third mode of operation.
    [0004]
    4. Power conversion system (10) according to claim 3, characterized in that the power stage controller (220) provides the second control signal (224) to pulse width modulate the second device. switching (210) in the third operating mode.
    [0005]
    5. Power conversion system (10), according to claim 3, characterized in that the second switching device (210) is an insulated gate bipolar transistor (IGBT).
    [0006]
    6. Power conversion system (10) according to claim 1, characterized by the fact that the operating mode of the individual dynamic preload and braking circuits (220) is determined at least partially according to a voltage of DC bus of the DC bus circuit (130).
    [0007]
    7. Method (300) for operating individual power stages (100) in a multilevel inverter (40), the method (300) characterized by the fact that it comprises: if a DC bus voltage of a given power stage (100) is less than a first threshold value (THPC), precharging (306) a DC bus capacitance (C) of the given power stage (100) via a resistor (206); if the DC bus voltage of the given power stage is greater than a second threshold value (THDB), connect (312) the resistor (206) in parallel with the capacitor (C) of the DC bus circuit (130) for dynamic braking of a load (50) driven by the multilevel inverter (40), the second threshold value (THDB) being greater than the first threshold value (THPC); and bypassing (310) the resistor (206) to allow current to flow from a rectifier circuit (120) to a switching circuit (140) of the given power stage (100) if the DC bus voltage is between the first and second. threshold values (THPC, THDB).
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3757197A|1972-07-25|1973-09-04|Gen Electric|Amping voltage on series compensating capacitor series parallel compensated current source inverter with means for cl|
    US4039914A|1975-11-25|1977-08-02|General Electric Company|Dynamic braking in controlled current motor drive systems|
    JPS605151B2|1978-04-05|1985-02-08|Hitachi Ltd|
    US4230979A|1978-04-10|1980-10-28|General Electric Company|Controlled current inverter and motor control system|
    US4215304A|1978-10-02|1980-07-29|General Electric Company|Motor/brake transitioning for an inverter driven a-c induction motor|
    US4545002A|1983-06-28|1985-10-01|General Electric Company|Thyristor voltage limiter for current source inverter|
    US4496899A|1983-06-28|1985-01-29|General Electric Company|Control for a force commutated current source var generator|
    US4870338A|1988-09-26|1989-09-26|Westinghouse Electric Corp.|Load commutated inverter induction motor drive|
    US4833389A|1988-09-26|1989-05-23|Westinghouse Electric Corp.|Current source inverter control system for load commutated induction motor drive|
    US5005115A|1989-07-28|1991-04-02|Westinghouse Electric Corp.|Forced-commutated current-source converter and AC motor drive using the same|
    US5041959A|1990-08-14|1991-08-20|General Electric Company|Control system for a current source converter supplying an AC bus|
    US5083039B1|1991-02-01|1999-11-16|Zond Energy Systems Inc|Variable speed wind turbine|
    US5293308A|1991-03-26|1994-03-08|Auckland Uniservices Limited|Inductive power distribution system|
    FR2735296B1|1995-06-08|1997-08-22|Sgs Thomson Microelectronics|CIRCUIT AND METHOD FOR CONTROLLING A CURRENT CALL LIMITER IN A POWER CONVERTER|
    WO1997004521A1|1995-07-18|1997-02-06|Midwest Research Institute|A variable speed wind turbine generator system with zero-sequence filter|
    JP3724523B2|1996-12-20|2005-12-07|株式会社安川電機|Inrush current prevention resistor protection method|
    US5875281A|1997-07-24|1999-02-23|Cableform, Inc.|DC solid state series wound motor drive|
    GB2330254B|1997-10-09|2000-10-18|Toshiba Kk|Multiple inverter system|
    US6058031A|1997-10-23|2000-05-02|General Electric Company|Five level high power motor drive converter and control system|
    DE19756777B4|1997-12-19|2005-07-21|Wobben, Aloys, Dipl.-Ing.|Method for operating a wind energy plant and wind energy plant|
    US5969957A|1998-02-04|1999-10-19|Soft Switching Technologies Corporation|Single phase to three phase converter|
    WO1999041830A1|1998-02-13|1999-08-19|The Texas A & M University System|Method and system for ride-through of an adjustable speed drive for voltage sags and short-term power interruptions|
    US5933339A|1998-03-23|1999-08-03|Electric Boat Corporation|Modular static power converter connected in a multi-level, multi-phase, multi-circuit configuration|
    US6262555B1|1998-10-02|2001-07-17|Robicon Corporation|Apparatus and method to generate braking torque in an AC drive|
    US6118676A|1998-11-06|2000-09-12|Soft Switching Technologies Corp.|Dynamic voltage sag correction|
    JP4284478B2|1998-12-28|2009-06-24|株式会社安川電機|Inverter device|
    US6166513A|1999-04-09|2000-12-26|Robicon Corporation|Four-quadrant AC-AC drive and method|
    US6377478B1|1999-05-28|2002-04-23|Toshiba International Corporation|Inverter device|
    US6301130B1|1999-09-01|2001-10-09|Robicon Corporation|Modular multi-level adjustable supply with parallel connected active inputs|
    US6166929A|2000-02-29|2000-12-26|Rockwell Technologies, Llc|CSI based drive having active damping control|
    WO2002045232A1|2000-11-30|2002-06-06|Mitsubishi Denki Kabushiki Kaisha|Inrush current limiting circuit, power source device and power conversion device|
    DE10119624A1|2001-04-20|2002-11-21|Aloys Wobben|Operating wind energy plant involves regulating power delivered from generator to electrical load, especially of electrical network, depending on current delivered to the load|
    JP3535477B2|2001-05-17|2004-06-07|株式会社日立製作所|Inverter device, inverter conversion method, and initial charging method of inverter device|
    US6714429B2|2001-08-15|2004-03-30|Astec International Limited|Active inrush current control for AC to DC converters|
    TW539934B|2001-12-06|2003-07-01|Delta Electronics Inc|Inrush current suppression circuit|
    KR100465805B1|2002-12-23|2005-01-13|삼성전자주식회사|Soft charging and dynamic braking device using motor|
    KR100534107B1|2003-02-14|2005-12-08|삼성전자주식회사|Power supply apparatus for motor|
    US7233129B2|2003-05-07|2007-06-19|Clipper Windpower Technology, Inc.|Generator with utility fault ride-through capability|
    KR100488528B1|2003-05-16|2005-05-11|삼성전자주식회사|Power supply device for motor|
    KR100566437B1|2003-11-11|2006-03-31|엘에스산전 주식회사|Inverter fault detection apparatus and method using phase shifting|
    AT504818A1|2004-07-30|2008-08-15|Windtec Consulting Gmbh|TRANSMISSION TRAIL OF A WIND POWER PLANT|
    US7158393B2|2005-03-11|2007-01-02|Soft Switching Technologies Corporation|Power conversion and voltage sag correction with regenerative loads|
    US7173399B2|2005-04-19|2007-02-06|General Electric Company|Integrated torsional mode damping system and method|
    US7508147B2|2005-05-19|2009-03-24|Siemens Energy & Automation, Inc.|Variable-frequency drive with regeneration capability|
    US7511975B2|2005-08-18|2009-03-31|Siemens Energy & Automation, Inc.|System and method for limiting AC inrush current|
    TWI301689B|2005-09-06|2008-10-01|Acbel Polytech Inc|
    US7511385B2|2005-11-11|2009-03-31|Converteam Ltd|Power converters|
    US7312537B1|2006-06-19|2007-12-25|General Electric Company|Methods and apparatus for supplying and/or absorbing reactive power|
    US7402965B2|2006-09-21|2008-07-22|Rockwell Automation Technologies, Inc.|DC common bus self-protection method and system|
    DE102006054768A1|2006-11-16|2008-05-21|Nordex Energy Gmbh|Method for operating a wind energy plant in power-limited operation|
    JP4845904B2|2008-02-08|2011-12-28|株式会社日立製作所|Wind power generation system|
    US7880343B2|2008-04-07|2011-02-01|Toshiba International Corporation|Drive isolation transformer controller and method|
    US7965529B2|2008-05-13|2011-06-21|Eaton Corporation|Voltage source inverter and medium voltage pre-charge circuit therefor|
    US8030791B2|2008-07-31|2011-10-04|Rockwell Automation Technologies, Inc.|Current source converter-based wind energy system|
    DE112008003996T5|2008-08-26|2011-07-21|Abb Technology Ab|driver unit|
    US7679208B1|2008-09-18|2010-03-16|Samsung Heavy Ind. Co., Ltd.|Apparatus and system for pitch angle control of wind turbine|
    US7929323B2|2008-09-26|2011-04-19|Rockwell Automation Technologies, Inc.|Method and apparatus for pre-charging power converters and diagnosing pre-charge faults|
    US8223515B2|2009-02-26|2012-07-17|TECO—Westinghouse Motor Company|Pre-charging an inverter using an auxiliary winding|
    US8587160B2|2009-09-04|2013-11-19|Rockwell Automation Technologies, Inc.|Grid fault ride-through for current source converter-based wind energy conversion systems|
    US8400085B2|2009-09-04|2013-03-19|Rockwell Automation Technologies, Inc.|Dynamic braking for current source converter based drive|
    JP5627264B2|2010-03-27|2014-11-19|三洋電機株式会社|Power supply device for vehicle and vehicle equipped with this power supply device|US9425705B2|2012-08-13|2016-08-23|Rockwell Automation Technologies, Inc.|Method and apparatus for bypassing cascaded H-bridgepower cells and power sub cell for multilevel inverter|
    US9712070B2|2013-06-04|2017-07-18|Toshiba Mitsubishi-Electric Industrial Systems Corporation|Power conversion device|
    KR101611010B1|2013-11-19|2016-04-08|엘에스산전 주식회사|Pre-charging circuit of inverter|
    AU2013408355B2|2013-12-18|2017-06-01|Otis Elevator Company|Bus capacitor bank configuration for a multi-level regenerative drive|
    US9787212B2|2014-05-05|2017-10-10|Rockwell Automation Technologies, Inc.|Motor drive with silicon carbide MOSFET switches|
    US9787210B2|2015-01-14|2017-10-10|Rockwell Automation Technologies, Inc.|Precharging apparatus and power converter|
    CN104967303A|2015-06-04|2015-10-07|中国科学院电工研究所|Self-starting control apparatus for intelligent electric energy router DC unit and self-starting method|
    JP6200457B2|2015-06-29|2017-09-20|ファナック株式会社|Motor driving device having means for detecting abnormal heat generation in initial charging circuit|
    WO2017053443A1|2015-09-21|2017-03-30|Lord Corporation|Improved actuator motion controller with regeneration compensation|
    CN105119512B|2015-09-23|2017-12-22|阳光电源股份有限公司|A kind of electric capacity charging method of multi-electrical level inverter and its application circuit|
    US10608545B2|2015-10-05|2020-03-31|Resilient Power Systems, LLC|Power management utilizing synchronous common coupling|
    DE112016004548T5|2015-10-05|2018-06-21|Resilient Power Systems, LLC|Power management using synchronous shared coupling|
    DE112015002616B4|2015-10-23|2019-01-31|Mitsubishi Electric Corporation|Converter arrangement|
    US9917544B2|2016-02-13|2018-03-13|Ge Aviation Systems, Llc|Method and power converter unit for operating a generator|
    US10439431B2|2016-02-23|2019-10-08|Vertiv Corporation|Method to reduce inrush currents in a transformer-less rectifier uninterruptible power supply system|
    US10020755B2|2016-03-03|2018-07-10|GM Global Technology Operations LLC|Apparatus for discharging a high-voltage bus|
    CN107294438A|2016-04-05|2017-10-24|德昌电机有限公司|Electric tool and its motor driven systems|
    US9837924B1|2016-06-02|2017-12-05|Rockwell Automation Technologies, Inc.|Precharge apparatus for power conversion system|
    CN106230057B|2016-08-18|2019-03-29|西北工业大学|A kind of precharge of frequency converter and error protection integrated apparatus|
    US10486537B2|2016-08-29|2019-11-26|Hamilton Sundstrand Corporation|Power generating systems having synchronous generator multiplex windings and multilevel inverters|
    DE102017201955A1|2017-02-08|2018-08-09|Geze Gmbh|braking device|
    US10381946B2|2017-02-10|2019-08-13|Regal Beloit America, Inc.|Three-phase to single-phase converter module for electrically commutated motors|
    GB2560195B|2017-03-03|2020-01-08|Ge Energy Power Conversion Technology Ltd|Electric circuits and power systems incorporating the same|
    CN106763185B|2017-03-07|2018-09-25|华中科技大学|A kind of power electronic controller for multiaxis magnetic suspension bearing|
    CN108574427A|2017-03-10|2018-09-25|西门子公司|Transducer brake unit and frequency converter|
    CN107707003B|2017-09-08|2020-12-08|广州双穗电气设备有限公司|PWM pulse width type constant-current charging type capacitor energy storage welding charging control system|
    EP3457550A1|2017-09-14|2019-03-20|Siemens Aktiengesellschaft|Coupling between circuits in drive networks|
    DE102019200181A1|2018-01-15|2019-07-18|Continental Teves Ag & Co. Ohg|Method of control, drive circuit, brake system and use|
    US11025052B2|2018-01-22|2021-06-01|Rockwell Automation Technologies, Inc.|SCR based AC precharge protection|
    CN110071622A|2018-01-23|2019-07-30|西门子公司|The multi-functional pre-charge circuit and its control device and method and frequency converter of frequency converter|
    CN108336763B|2018-02-08|2021-01-15|澄瑞电力科技（上海）有限公司|Active and reactive decoupling control-based parallel connection method of H-bridge cascaded shore power supply|
    GB201803765D0|2018-03-09|2018-04-25|Rolls Royce Plc|AC--AC Converter and method of operation|
    US10158299B1|2018-04-18|2018-12-18|Rockwell Automation Technologies, Inc.|Common voltage reduction for active front end drives|
    US10770987B2|2018-05-11|2020-09-08|Hamilton Sunstrand Corporation|Motor drive architecture for variable frequency alternating current loads|
    EP3618250B1|2018-08-29|2021-02-17|FRIWO Gerätebau GmbH|Inrush current limiting device and power factor correction circuit|
    CN110034705A|2019-04-09|2019-07-19|上海奇电电气科技股份有限公司|Load-balancing method and braking system|
    CN110138231A|2019-05-10|2019-08-16|珠海格力电器股份有限公司|Drive control circuit and its control method, driving control system, air conditioner|
    CN110224644B|2019-06-12|2020-12-11|上海艾为电子技术股份有限公司|Control method and driving circuit for controlling current ripple based on offset feedback voltage|
    US11142075B2|2019-08-08|2021-10-12|Hamilton Sundstrand Corporation|Efficient regenerative electrical braking|
    CN110460272A|2019-09-16|2019-11-15|江苏科技大学|High power permanent magnet synchronous motor energy bleeder and control method|
    US11211879B2|2019-09-23|2021-12-28|Rockwell Automation Technologies, Inc.|Capacitor size reduction and lifetime extension for cascaded H-bridge drives|
    CN110912467A|2019-12-13|2020-03-24|浙江禾川科技股份有限公司|Motor driving circuit|
    法律状态:
    2015-11-03| B03A| Publication of a patent application or of a certificate of addition of invention [chapter 3.1 patent gazette]|
    2018-11-13| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2020-02-11| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2021-01-05| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application [chapter 6.1 patent gazette]|
    2021-04-13| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-05-18| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 08/04/2014, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US13/858,187|US9083274B2|2013-04-08|2013-04-08|Power stage precharging and dynamic braking apparatus for multilevel inverter|
    US13/858,187|2013-04-08|
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