• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
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  • 优先权
    • 专利摘要:
    ACTIVE FRONT END POWER CONVERTER WITH NOMINAL CAPACITY REDUCTION IN BOOST MODE TO PROTECT FILTER INDUCTOR. Methods and equipment for controlling a power converter to protect input filter inductors from overheating are presented, in which an active front end rectifier (AFE) is operated in a boost mode to provide boosted IDO voltage at a current value of rated derating output selected in accordance with the amount of DC bus voltage boost corresponding to a maximum load condition to which the filter inductors do not overheat.
    公开号:BR102014006330B1
    申请号:R102014006330-7
    申请日:2014-03-17
    公开日:2021-04-20
    发明作者:H02M 7/217；H02M 1/42
    申请人:Rockwell Automation Technologies, Inc；
    IPC主号:
    专利说明:

    TECHNICAL FIELD
    [001] The present disclosure relates to a technical field of power conversion, and particularly to a method and equipment for reducing nominal capacity in boost mode. FUNDAMENTALS
    [002] Power conversion systems are used to supply AC output power to a load, such as motor drives with an inverter stage that drives an AC motor. Active Front End Converters (AFE) use a switching rectifier to convert AC input power to supply DC power to a bus, with the inverter switches converting the DC bus to supply currents to drive the load. Such active front-end converters are typically coupled to input filters, such as LCL filter circuits connected to each power phase. Since the front end rectifier is a switching circuit, the input filter operates to prevent the introduction of unwanted harmonic content into the mains or other power supply. Filter components, including filter inductors, are typically designed to the rated capacity of the power converter, where oversizing input filter components adds cost to the system and takes up valuable enclosure space. However, situations can occur where there are voltage drops in the network, or where an available input source voltage is lower than the nominal AC input voltage for which the converter was designed. In some applications, in addition, it may be desirable to operate a higher voltage motor or load even if the source voltage is low, for example a 400 V input voltage to drive a 460 V motor. active front end rectifier can be operated in boost mode to essentially increase the gain of the front end converter, thereby amplifying the DC bus voltage. Under full load conditions, however, operation in boost mode of the active front-end rectifier produces increased ripple and other harmonics, which can overheat the filter inductor core. One or more thermal shutdown switches can be positioned to detect the inductor temperature rise and cause a safe system shutdown. However, disarming the engine may not be desirable in some applications and therefore it is desirable to have a technique that allows the system to operate in boost mode without shutdown. In addition, such a thermal switch may be positioned some distance from the inductor core for the purpose of detecting temperature increases due to multiple causes, such as detecting whether a system fan is off while a full load is being turned on and therefore it may be unable to quickly detect overheating in the filter inductor core. Adding multiple thermal switches can solve this problem, but this technique adds even more cost and complexity to the system. Consequently, there is a need for improved power converter equipment and operating techniques to facilitate selective operation with an active front end in boost mode while mitigating or avoiding thermal stress on the filter inductors. SUMMARY
    [003] Several aspects of the present disclosure are now summarized to facilitate a basic understanding of the disclosure, where this summary is not an extensive view of the disclosure, and is neither intended to identify any elements of the disclosure nor to delimit its scope. Rather, the main purpose of this summary is to present several concepts of the revelation in simplified form prior to the more detailed description given below. The present disclosure provides motor drives and other power conversion systems as well as their control techniques, in which the power converter is selectively reduced from rated capacity in boost mode to protect thermal voltage filter inductors.
    [004] A converter operation method is provided, in which a rectifier is operated in a boost mode to provide a DC bus voltage above the maximum line-to-line AC input voltage, and an output current value is determined. of rated capacity reduction according to the input voltage and according to the amount of DC bus voltage boost, where the rated capacity reduction output current is less than or equal to the maximum rated output current of the power converter . In some implementations, a front-end active power converter drives a DC load at a rated derating rectifier output current level, where the rectifier DC load can be an output inverter that provides a DC current command to the rectifier according to the value of the rated derating output current. In other applications, the active front end converter operates in boost mode and supplies DC output current to other forms of DC load such as a battery charging system, solar panel, fuel cell, etc. according to the rated derating output current value. By this technique, thermal stress on the filter choke components can be mitigated or avoided if the front end converter is operated in boost mode, without the need to oversize the filter chokes. In some embodiments, the rated derating output current value is obtained from a lookup table corresponding to the line-to-line AC input voltage, and the method may involve selective interpolation of lookup table values to obtain the value of the rated derating output current. Multiple lookup tables can be used individually, with a given lookup table being selected according to an associated input voltage level. In some implementations, the DC bus voltage boost amounts and corresponding values of the rated capacity reduction output currents from the table or tables correspond to the maximum steady-state load operation conditions of the power converter for which an inductor centered filter is designed not to overheat. In some embodiments, a rated derating formula is solved according to the amount of DC bus voltage boost in order to determine the value of the rated derating output current. Non-transient computer readable media are provided with computer executable instructions for implementing the methods of operation of the power conversion system.
    [005] Power conversion systems are provided, including an active rectifier that provides a DC bus voltage, and a controller operates the rectifier in a boost mode to provide the DC bus voltage above the maximum AC line-to-line input voltage. line. The controller determines a value of the rated derating output current in accordance with the line-to-line AC output voltage and in accordance with an amount of DC bus voltage boost, and selectively operates the rectifier in accordance with the value of the rated derating output current. In some embodiments, the value of the rated capacity reduction output current and the corresponding amount of DC bus voltage boost corresponds to a steady-state maximum load operating condition of the power converter for which one or more inductors filter are designed not to overheat. The controller in some embodiments obtains the rated derating output current value from a lookup table according to the DC bus voltage boost amount, and the controller can selectively interpolate current values from the lookup table to obtain the rated derating output current value. In addition, the controller can select a given one from a plurality of lookup tables corresponding to the line-to-line AC input voltage, and can use interpolation of selected lookup table values to obtain the rated derating output current value. . In various implementations, in addition, the controller can determine the value of the rated derating output current by solving at least one derating formula according to the amount of DC bus voltage boost. BRIEF DESCRIPTION OF THE DRAWINGS
    [006] The following description and drawings present some illustrative implementations of the disclosure in detail, which are indicative of several exemplary ways in which the various principles of the disclosure may be embodied. The illustrated examples, however, are not exhaustive of the many possible modalities of disclosure. Other objectives, advantages and new aspects of the disclosure will be presented in the detailed description below when considered in conjunction with the drawings, in which:
    [007] Fig. 1 is a schematic diagram illustrating an exemplary motor drive power converter with rated capacity reduction control in boost mode to protect input filter inductors in accordance with one or more aspects of the present. revelation;
    [008] Fig. 2 is a flow diagram illustrating a method of operating an exemplary power converter to selectively reduce the rated capacity of a power converter output current during front-end rectifier boost mode of operation active;
    [009] Fig. 3 is a graph illustrating an exemplary output current rated capacity reduction curve as a function of DC voltage boost;
    [010] Fig. 4 illustrates an exemplary lookup table to selectively reduce the rated capacity of a power converter output current in accordance with DC voltage boost;
    [011] Fig. 5 is a graph illustrating the harmonic content of filter inductor current for a power converter with an active front end in normal operation without reinforcement;
    [012] Fig. 6 is a graph illustrating the harmonic content of filter inductor current for a power converter with active front-end rectifier boost mode operation without derating current rated capacity; and
    [013] Fig. 7 is a schematic diagram illustrating another mode of an active front end power converter driving a DC load with a voltage boosted at a rated capacity reduction output current level according to the present disclosure . DETAILED DESCRIPTION
    [014] With reference now to the figures, various modalities or implementations are further described in conjunction with the drawings, where similar reference numerals are used to refer to similar elements throughout, and where the various aspects are not necessarily drawn the scale. Methods and equipment are disclosed for operating a motor drive or other active front end power conversion systems with an active active front end operating in a boost mode to generate a DC bus with a voltage 0 greater than the maximum input voltage level AC line by line. Although illustrated and described below in the context of AC motor drives, the various concepts of the present disclosure find utility in association with other forms of power conversion systems that have an active front end converter driving a DC load, where the present disclosure does not is limited to illustrated examples.
    [015] Fig. 1 illustrates an exemplary motor drive power conversion system 10 that receives single-phase or multi-phase AC input power from an external power supply 2. The illustrated example receives a three-phase input, but single-phase or multi-phase modalities are possible. The motor drive 10 includes an input filter circuit 20, in this case a three-phase LCL filter with mains side inductors L1, L2 and L3 connected to the power supply 2 power terminals as well as converter side inductors connected to L4, L5 and L6 series, with filter capacitors C1, C2 and C3 connected between the corresponding mains and converter side inductors and a connecting common node, which can but does not need to be connected to a system earth. Although illustrated in the context of a 20 three-phase LCL filter circuit, other alternative circuit configurations may be used, including without limitation LC filters.
    [016] The motor drive 10 includes an input filter circuit 20, a rectifier 30, a DC bus or DC link circuit 40 and an output inverter 50, with the rectifier 30 and the inverter 50 being operated by a controller 60. Controller 60 includes a rectifier controller 62 with an associated booster logic 64, an inverter controller 66, and a rated derate control component 70 operative using one or more lookup tables (LUTs) 72 and/ or one or more rated derating formulas 74 for selectively derating the output current of the rectifier when rectifier 30 is operative in boost mode as described further below. In the illustrated example, the rated derating control component 70 provides a rated derating output current value 76 to the inverter switching controller 66, which in turn provides a DC IDC current command value to the rectifier switching controller 62 for the purpose of operating the rectifier 30 at a rated derating output current level. In other possible implementations, the rated derating components 70 provide a rated derating output current value 76 directly to the rectifier switching controller 62 (Fig. 7 below).
    [017] Controller 60 and its components can be implemented as any suitable hardware, software executed by processor, firmware executed by processor, logic, and/or combinations thereof where illustrated controller 60 can be implemented largely in software or firmware performed by processor providing various control functions whereby controller 60 receives feedback and/or input signals and/or values (e.g., setpoint(s)) and provides rectifier and inverter switching control signals 62a and 66a to operate the switching devices S1-S6 of the rectifier 30 and switches S7-S12 of the inverter 50 to convert input power to provide AC output power to drive the load 4. In addition, the controller 60 and its components 62, 64 , 66, 70, and/or 72 may be implemented in a single processor-based device, such as a microprocessor, microcontroller, FPGA, etc., or one or more of these may be implemented. separately in a unitary mode or distributed over two or more processor devices.
    [018] Motor drive 10 provides an active front end (AFE) that includes a switching rectifier (also called a converter) 30 that receives three-phase power from source 2 through filter circuit 20. Rectifier 30 includes rectifier switches S1-S6, which may be isolated-pass bipolar transistors (IGBTs) or other suitable forms of semiconductor based switching devices operable in accordance with a corresponding rectifier switching control signal 62a to selectively conduct current when actuated. Furthermore, as seen in Fig. 1, diodes are connected via the individual IGBTs S1-S6. In operation, the switching of rectifier switches S1-S6 is controlled in accordance with pulse width modulated rectifier switching control signals 62a to provide active rectification of AC input power from source 2 to provide a DC bus voltage. Vdc through a DC bus capacitance C4 in a DC link circuit 40. Rectifier 30, furthermore, can be selectively operated by rectifier switching control component 62 of motor drive controller 60 for normal operation or motor operation. boost mode according to boost control logic 64. In boost operation, rectifier switching control component 62 provides signals 62a to cause rectifier 30 to generate the DC bus voltage at a level above the AC line-to-line maximum input voltage received from input source 2.
    [019] The drive 10 in Fig. 1 further includes an inverter 50 with switches S7-S12 coupled to receive power from the DC bus 40 and to supply AC output power to a motor or other load 4. The inverter switches S7-S12 are operated in accordance with switching control signals 66a from an inverter switching control component 66 of the drive controller 60, and can be any form of suitable high speed switching devices, including without limitation IGBTs. The inverter controller 66 also provides a DC IDC current command signal or value to the rectifier switching controller 62 to cause the rectifier controller 62 to operate the rectifier switches S1-S6 to properly supply a DC output current to the DC link circuit 40. In addition, controller 60 receives various input signals or values, including setpoint signals or values for desired output operation, such as speed, position, torque, etc. of the motor, as well as signals or feedback values representing operating values of various portions of the motor drive 10. Among these are a DC bus voltage signal or value 78 representing the DC bus voltage Vdc, and a signal or value 79 which represents the line-to-line AC input voltage value.
    [020] Referring also to Figs 5 and 6, the operation of the active front end rectifier 30 in boost mode can occur according to a variety of circumstances. For example, a 10 motor drive can be designed for a rated output current (or power) based on receiving AC input power at a given rated voltage level or range, such as 480 V AC in an example. . In some embodiments, controller 60 uses boost control component 64 to selectively switch rectifier switching control component 64 from normal operation to boost, and provides an additional amount of DC bus voltage boost needed to operate the motor. from the inverter (for example, a DC bus voltage booster amount) 64a (ΔVdc) to the rated capacity reduction system 70 as well as to the rectifier switching controller 62. In some implementations, in addition, the booster amount 64a it can be pre-programmed in the controller 60, or it can be configured by the user. For example, the motor drive 10 can be designed for a certain value or range of AC input voltage (eg 480V, 60Hz) but can be installed for use in an environment that only provides 380V AC input. . In such a situation, controller 60 may be programmed with a fixed DC voltage boost value 64a for use by rectifier switching controller 62 and nominal derating system 70.
    [021] As noted in Fig. 5, normal operation of the rectifier 30 (without booster) with a nominal AC input voltage results in a certain content of harmonics in the filter circuit 20. Fig. 5 shows a graph 300 that illustrates the harmonic content as a percentage of the maximum rated current for an exemplary motor drive operated with a 400 V AC input providing a 560 V DC bus without the use of boost operation, and with an inverter output 50 providing a 380 output V AC to a load. Under these conditions, the regular DC bus voltage to operate a 400V motor will be 560V DC. In this unreinforced rectifier operating condition, a certain harmonic level will be seen at 302, approximately close to 4 kHz for an AC input frequency of 60 Hz. DC bus needs to be increased to 680 V DC. As a result, the amount of additional DC voltage boost is 680-560 = 120 V DC. A graph 310 in Fig. 6 shows the percent frequency content of the maximum rated current for the same converter 10 operated again from a 400 V AC input source, with active front end rectifier boost operation being used to boost the DC Vdc voltage above the maximum line-to-line input voltage, in this case to 680 V DC. In this case, in addition, the output inverter 50 provides an output of 460 V AC without derating the rated capacity of the rectifier output current. As seen in Fig. 6, the corresponding content of maximum current 312 harmonics is significantly higher than the corresponding content of 302 harmonics in the unreinforced example of Fig. 5.
    [022] The inventors evaluated that the increase in harmonic content in the booster mode leads to an increase in the operating temperature of the inductor cores of the inductors of the L4-L6 filter circuit. In particular, the L4-L6 converter side inductors may suffer from thermal stress caused by the boosting operation of the active front end rectifier 30. In this regard, motor drives and other end power conversion systems Active front 10 are typically designed around a rated capacity condition, including nominal AC input voltage levels and corresponding DC bus voltages and currents, as well as drive output current or power levels. In order to save on a design with respect to cost, heating and cabinet space, L input filter inductors are typically designed around the rated capacity condition and therefore switching operation in boost mode can cause excessive thermal stress on the inductors as increased harmonics increase the temperature of the core structure. As noted above, thermal shutdown switches can be used to try to detect overheating of inductor cores, but excessive sensor coverage is both costly and adds complexity to the motor drive system 10. In addition, many situations occur in practice where it is It is desirable to operate a power converter 10 with the rectifier boosting the DC bus voltage beyond the value of the maximum AC input line voltage. Simply providing thermal shutdown capability can protect the L-filter inductors from thermal stress, but it can lead to unwanted system shutdowns. Another technique to solve this problem is to design L-filter inductors to accommodate the higher harmonic content associated with boost mode operation, but this requires increasing the size and cost of the input filter circuit 20 and its components.
    [023] The present disclosure solves these drawbacks of the prior art by selectively reducing the rated capacity of the motor drive output, in particular the maximum output current of the rectifier 30, based on operation in booster mode. Using this new technique, the L-filter chokes do not need to be oversized, and the system can operate intermittently or even continuously in rectifier boost mode without triggering unwanted shutdowns, while protecting the L-filter chokes from thermal stress. In particular, controller 60 utilizes rated derating system 70 which provides inverter switching controller 66 with a rated derating output current value 76 during active front end boost mode operation. The inverter controller 66 in this mode provides a DC current command value reduced from the rated capacity or decreased IDC to the rectifier controller 62 for the purpose of operating the rectifier 30 according to the output current value reduced from the rated capacity 76 during the front end reinforcement mode activates. The amount of nominal capacity reduction 76 is determined according to the AC input voltage present at source 2 (or the AC input voltage level at other measurement points in the LCL filter circuit) based on one or more signals or feedback values 79, and also according to the DC bus voltage (signal or feedback value 78) and an additional DC bus voltage boost amount 64a (ΔVdc) obtained from the boost control component 64. In some embodiments , the reduced output current value of the nominal capacity 76 can be represented as a percentage of the nominal capacity of the output current for both the inverter 50 and the rectifier 30. In practice, in addition, the reduced output current value of the rated capacity 76 is less than or equal to the maximum output current rating for power conversion system 10. In the embodiment of Fig. 7 below, the reduced output current value of rated capacity 76 is given directly to the rectifier switching controller 62, and may be representative of a percentage of the rated capacity of the DC output current for the rectifier 30.
    [024] Referring also to Fig. 2, a method 100 for operating a power conversion system is illustrated, which can be used in the motor drive 10 of Fig. 1 or in the active front end converter 10 of Fig. 7 below, or in any other power conversion system. Although method 100 is illustrated and described below in the form of a series of actions or events, it will be understood that the various methods of disclosure are not limited by the illustrated ordering of such actions or events. In this regard, except as specifically provided below, some actions or events may occur in different order and/or concurrently with other actions or events in addition to those illustrated and described herein in accordance with the disclosure. It is further noted that not all illustrated steps may be necessary to implement a process or method in accordance with the present disclosure, and that one or more of such actions may be combined. Illustrated method 100 and other methods of the disclosure may be implemented in hardware, processor-executed software, or combinations thereof, such as in exemplary controller 60 described herein, and may be embodied in the form of computer-executable instructions stored on a computer-readable medium. tangible, non-transient computer, such as in a memory operatively associated with controller 60 in one example.
    [025] The drive 10 or its rectifier 30 can be operated with a 100% normal output current capacity as shown at 102 in Fig. 2. A determination is made at 104 as to whether the rectifier 30 is operating in the boost mode. If not (NO to 104), drive 10 continues to operate at rated output current capacity at 102. If the rectifier is in boost mode (YES at 104), controller 60 determines a reduced output current value of rated capacity (76 in Fig. 1 above) according to the line-to-line AC input voltage value (eg from signal or feedback value 79) and according to the amount of DC bus voltage boost 64a of boost control component 64, indicated in the figure as ΔVdc. In some embodiments, the amount of voltage boost is expressed in terms of DC volts, although this is not a strict requirement. For example, if the nominal DC voltage (eg approximately the maximum line-to-line AC input voltage value) is 560 V DC, operating in boost mode to provide a DC bus voltage of 680 V DC would represent an amount of 120 V DC bus voltage booster (ΔVdc = 120 V DC). Other suitable representation schemes can be used whereby an amount of DC bus voltage boost is used which somehow represents the effect of boost mode operation on the DC bus voltage Vdc.
    [026] Determining the reduced output current value of rated capacity 76 can be performed in several ways. In one possible embodiment, method 100 of Fig. 2 allows the use of a lookup table (eg, lookup table 72 in Fig. 1), with the reduced output current value of rated capacity 76 being obtained from from lookup table 72 corresponding to the line-to-line AC input voltage value. This can be accomplished, for example, as noted at 106 in Fig. 2, by indexing the lookup table 72 that corresponds to the AC input voltage level for the purpose of determining the nominal derating value of the output current. drive 76 associated with voltage booster DC 64a ΔVdc. In another possible modality (shown in dashed line in Fig. 2) a nominal capacity reduction formula can be solved in 107 corresponding to the AC input voltage level to determine the nominal capacity reduction value of the output current of the rectifier or driver 76 according to the amount of DC voltage boost ΔVdc 64a. The drive output inverter 50 is then operated at 108 in accordance with the output current rated capacity derating value 76, and provides the DC current command value to the rectifier switching controller 62 to operate the rectifier 30 according to the rated capacity reduction value 76. For example, the motor drive 10 and its inverter 50 can receive one or more setpoint values representing a desired load drive condition, such as a torque, speed , position, etc. of set point. The inverter controller 66 in some embodiments uses the output current rated capacity derating value 76 as a maximum limit of the output current supplied to the motor load 4. Therefore, the inverter 50 will provide outputs including the command value of DC current desired IDC so that the nominal capacity derating value 76 is not exceeded, thereby ensuring that the filter inductors L do not experience thermal stress. The process 100 then returns to again determine at 104 whether the rectifier continues to operate in the boost mode as described above, and the process thus continues as described above.
    [027] Referring also to Figs 3 and 4, Fig. 3 shows a graph 200 representing a curve 76 of nominal current in percent versus the amount of DC voltage boost for a line-to-line input voltage level. 400 V AC, and Fig. 4 illustrates an exemplary lookup table 72 corresponding to curve 202 in Fig. 3. The table in Fig. 4 in this example is chosen from a plurality of such tables 72, with each table 72 being associated with a specific value of AC input voltage. As seen in Fig. 3, when the DC bus voltage is 114 V above normal, the rated current of the driver or rectifier is 100% (for example, the rated capacity derating output current value 76 is equal to the current maximum output rating for the power converter 10 in the assembly or its rectifier 30). In this case, curve 76 represents the steady-state maximum load conditions for which the L-filter chokes are not thermally stressed and, therefore, boosting the DC bus voltage by 114 V will allow the L-filter chokes to avoid overheating . However, as the amount of DC bus voltage boost 64a increases to 160V and 184V, the nominal capacity derating output current value 76 drops to approximately 93% and 85%, respectively. At these levels, therefore, the control of the inverter 50, and therefore of the rectifier 30, to provide no more than this amount of output current rated derating allows the L-filter inductors to continue operation within the proper thermal range. In some embodiments, formula 74 (Fig. 1) can be used to estimate the nominal capacity derating curve 76 for any given amount of DC bus voltage boost, eg, a polynomial function.
    [028] In addition, the curve 76 in Fig. 3 and a corresponding lookup table 72 in Fig. 4 correspond to a specific line-to-line AC input voltage value, where one or more of such parametric functions 74 and/or 72 lookup tables can be provided. Therefore, for example, the rated derating system 70 in Fig. 1 can be configured to select a suitable (eg, closest) function 74 or lookup table 72 based on the line-to-line AC input voltage present in the system 10 (for example, according to the input voltage signal or feedback value 79), and to use that function or lookup table to determine the value of the rated capacity reduction output current 76 in accordance with the value of the AC input line voltage and according to the amount of DC bus voltage booster 64a. Also, as seen in Fig. 4, some modalities may use different lookup tables 72 for different AC input voltage levels, such as 380V, 390V, 400V, etc. Likewise, the rated capacity reduction system 70 may utilize one of a plurality of rated capacity reduction formulas 74, each corresponding to a different AC input voltage level, with the rated capacity reduction system 70 selecting a closer or more suitable formula 74 according to feedback 79. In one possible embodiment, the rated derating system 70 of controller 60 is configured to dynamically receive the input voltage feedback signal or value 79 and choose the nearest lookup table 72 for use in determining the value of the rated derating output current 76. Similarly, the rated derating system 70 can select from a plurality of derating formulas 74 on the basis of at the AC input value 79.
    [029] When using a selected lookup table 72, in addition, the rated derating system 70 of the controller 60 can use interpolation for the determination of the rated derating output current value. As seen in Fig. 4, for example, controller 60 can interpolate between nominal capacity scaling output current values 76 of lookup table 72 corresponding to DC bus voltage boost amounts 64a above and below the boost amount. of DC bus voltage present in the power system 10 to obtain the value of the rated capacity reduction output current 76 for use in the operation of the inverter 50 and therefore of the rectifier 30. For example, if the amount of voltage boost of DC bus 64a in the example in Fig. 4 was 175 V DC (ΔVdc = 175), controller 60 could use any suitable interpolation technique (eg linear or otherwise) with corresponding derating output current values nominal (eg 91% and 87%) corresponding to the DC bus voltage boost amounts (eg 170 V DC and 180 V DC) above and below the current voltage boost for the purpose of obtaining or computing the v alue 76 through interpolation (eg 89% in this example).
    [030] In some implementations, the values of the lookup table 72 and the parameters of the nominal capacity reduction formulas 74 can be selected to match the full load steady state operating conditions of the power converter 10 for which the input filter inductor (eg L) is designed not to overheat. This correlation can be obtained by any suitable means, such as by empirical testing to obtain output current rated capacity derating values 76 for several different DC bus voltage boost values 64a in which the inductor core temperature is in the nominal value (or within an acceptable range thereof), and construction of a corresponding table 72 for each of several AC input voltage values. Similarly, experimental data can be used to obtain formulas 74 (eg, linear, polynomial, etc.) based on curve fitting or other suitable mathematical technique.
    [031] Fig. 7 illustrates another exemplary power conversion system, in this case an active front end converter 10 with a switching rectifier 30 and corresponding switching rectifier controller 62 as described above. In this example, however, the rectifier 30 provides a DC output to drive an external DC load 50. In this case, an active front end output rated derating component 70 provides the value of the rated derating output current 76 to rectifier switching controller 62 directly. In operation, the rectifier controller 62 provides the switching control signals 62a in boost mode to provide boosted or boosted DC output voltage to load 50 above the maximum line-to-line AC input voltage value, and also controls the current. output load DC ICARGA supplied to load 50 so as not to exceed the rated capacity derating output current value 76. As seen in Fig. 7, therefore, the concepts of the present disclosure advantageously facilitate operation in boost mode AFE with rated capacity reduction rectifier output current limiting in a variety of applications for any number of types of DC 50 loads, such as charging capacitor banks, fuel cells, solar cells, etc., in addition to applications above described motor drive systems in which the rectifier 30 provides a boosted DC voltage across the DC bus circuit for use by an inverter load.
    [032] According to further aspects of the present disclosure, a non-transient computer readable medium is provided, such as a computer memory, a memory within a power converter control system (e.g., controller 100), a CD-ROM, floppy disk, flash drive, database, server, computer, etc.), which includes computer-executable instructions for performing the methods described above. The above examples are merely illustrative of several possible embodiments of various aspects of the present disclosure, where equivalent changes and/or modifications will occur to others skilled in the art after reading and understanding this specification and accompanying drawings. In particular with regard to the various functions performed by the components described above (mechanisms, devices, systems, circuits, and the like), the terms (including a reference to a "means") 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, that performs the specified function of the described component (that is, that is functionally equivalent), even if not structurally equivalent to disclosed structure that performs the function in the illustrated implementations of the disclosure. Furthermore, although a specific 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 desirable and advantageous for any given or specific application. Also, to the extent that the terms "including", "includes", "having", "has", "with", or its variants are used in the detailed description and/or in the claims, such terms are intended to be inclusive. similarly to the term "comprising".

    权利要求:
    Claims (14)
    [0001]
    1. Method (100) for operating a power conversion system (10), the method comprising: operating a rectifier (30) of the power conversion system (10) in a boost mode to provide a voltage of DC output (Vdc) greater than a maximum line-to-line AC input voltage value; determine a rated capacity reduction output current value (76) according to the maximum line-to-line AC input voltage value and according to an amount of DC output voltage boost ( reforçoVdc), the current value rated capacity reduction output (76) being less than or equal to the maximum rated output current for the rectifier (30); and controls the DC output load current of the rectifier (30) supplied to a DC load in accordance with the rated derating output current value.
    [0002]
    2. Method (100), according to claim 1, characterized in that the determination of the rated capacity reduction output current value (76) comprises: obtaining the rated capacity reduction output current value (76) corresponding to the amount of DC output voltage boost (ΔVdc) from a lookup table (72) corresponding to the line-to-line AC input voltage value.
    [0003]
    3. Method (100), according to claim 1, characterized in that the determination of the rated capacity reduction output current value (76) comprises: selectively interpolating two rated capacity reduction output current values from the table values (72) corresponding to the DC output voltage boost amounts (ΔVdc) above and below the DC output voltage boost amounts present in the power conversion system (10) to obtain the step-down output current value of rated capacity (76).
    [0004]
    4. Method (100), according to claim 2, characterized in that the DC output voltage boost amounts (ΔVdc) and corresponding nominal capacity reduction output current values (76) of the search table (72 ) meet the steady-state full load operating conditions of the power conversion system (10) for which an input filter inductor (L1-L6) is designed not to overheat.
    [0005]
    5. Method (100), according to claim 1, characterized in that the determination of the rated capacity reduction output current value (76) comprises: solving at least one rated capacity reduction formula (74) in accordance with with the amount of boosting the DC output voltage (ΔVdc).
    [0006]
    6. Method (100) according to claim 1, characterized in that the DC load of the rectifier is an output inverter.
    [0007]
    7. Method (100) according to claim 6, characterized in that the output inverter provides a DC current command to the rectifier according to the output current value reduction.
    [0008]
    8. Non-transient computer readable medium with computer executable instructions for operating a power conversion system (10), the computer readable medium characterized by comprising computer executable instructions for: operating a rectifier (30) of the conversion system (10) power supply in a boost mode to provide a DC output voltage (Vdc) greater than a maximum line-to-line AC input voltage value; determine a nominal capacity reduction output current value (76) according to the AC input voltage value and according to the DC output voltage boost amount (Vdc), the reduction output current value of rated capacity (76) being less than or equal to a maximum rated output current for the rectifier (30); and controlling the DC output load current by the rectifier (30) providing a DC load in accordance with the rated derating output current value.
    [0009]
    9. A power conversion system (10) comprising: a filter circuit (20) comprising at least one inductor (L); an active rectifier (30) comprising a plurality of rectifier switching devices (S1-S6) for receiving AC input power from an external power supply (2) through the filter circuit (20) and for providing a voltage of DC output (Vdc) to a DC load (50); the system characterized by further comprising: a controller (60) that provides rectifier control signals (62a) to rectifier switching devices (S1-S6) to selectively operate the rectifier (30) in a boost mode to supply voltage output DC (Vdc) greater than a maximum line-to-line AC input voltage value, the controller (60) being operative to determine a nominal derating output current value (76) according to the voltage value AC input line-to-line and according to an amount of DC output voltage booster (ΔVdc), and to selectively control a DC output current from the rectifier (30) supplied to the DC load in accordance with the output current value of nominal capacity reduction (76).
    [0010]
    10. Power conversion system (10), according to claim 9, characterized in that the controller (60) is operative to obtain the nominal capacity reduction output current value (76) corresponding to the amount of reinforcement of DC output voltage (ΔVdc) from a lookup table (72) corresponding to the line-to-line AC input voltage value.
    [0011]
    11. Power conversion system (10), according to claim 9, characterized in that the controller (60) is operative to determine the value of the rated output reduction output current (76) by solving at least one nominal capacity reduction formula (74) according to the amount of DC output voltage boost (ΔVdc).
    [0012]
    12. Power conversion system (10), according to claim 9, characterized in that the nominal capacity reduction output current value (76) and the corresponding amount of DC output voltage boost (ΔVdc) correspond to a steady state full load operating condition of the power conversion system (10) for which the at least one inductor (L) is designed not to overheat.
    [0013]
    13. Power conversion system (10), according to claim 9, characterized in that it further comprises the DC load, in which the DC load of the rectifier is an output inverter.
    [0014]
    14. Power conversion system (10), according to claim 13, characterized in that the output inverter provides a DC current command to the rectifier according to the rated capacity reduction output current value.
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    同族专利:
    公开号 | 公开日
    US20140268953A1|2014-09-18|
    BR102014006330A2|2016-07-12|
    US9461559B2|2016-10-04|
    CN104052306A|2014-09-17|
    EP2779391A1|2014-09-17|
    CN104052306B|2017-06-23|
    US20170025981A1|2017-01-26|
    US9973137B2|2018-05-15|
    EP2779391B1|2019-01-16|
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    法律状态:
    2016-07-12| 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]|
    2020-01-14| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-12-22| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application [chapter 6.1 patent gazette]|
    2021-03-30| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-04-20| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 17/03/2014, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US13/832,214|US9461559B2|2013-03-15|2013-03-15|Active front end power converter with boost mode derating to protect filter inductor|
    US13/832,214|2013-03-15|
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