• 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:
    An inverter for diagnostic X-ray equipment, comprising a thyristor bridge with an input diagonal connected in series with two commutating inductances across a DC power supply, is provided with a start-stop circuit which includes an ancillary thyristor connected in series with a diode and a current-limiting impedance across one of the bridge arms. On start-up, the ancillary thyristor is triggered simultaneously with the diagonally opposite bridge thyristor in order to connect the current-limiting impedance in series with the AC output diagonal of the bridge during the first half-period; for a quick cutoff, the ancillary thyristor and the associated bridge thyristor are turned on together whereby two previously charged quenching capacitors, one of them included in the start-stop circuit, are discharged through the commutating inductance in series with the associated bridge arm to terminate conduction in another bridge arm fed through the same commutating inductance. A protective unit connected across the input diagonal of the bridge includes a further capacitor, charged from an auxiliary voltage source, which reverse-biases the bridge thyristors by way of another thyristor fired upon detection of a short circuit or overload.
    公开号:SU841618A3
    申请号:SU792751302
    申请日:1979-04-05
    公开日:1981-06-23
    发明作者:Чонтош Петер；Хентер Ласло；Кальман Ласло；Кондор Тибор；Вайн Иштван
    申请人:Медикор Мювек (Инопредприятие)；
    IPC主号:
    专利说明:

    You have a circuit consisting of four thyristors, four switching capacitors, four return diodes, and connected to the power rails through inductively connected switching inductances 2.
    However, the output of the device is not only loaded with a complex load impedance, depending on the parameters of the X-ray tube and appearing on the primary winding of a high-voltage or control transformer, but also an unstable reactive nature due to a transient caused by the residual magnetic induction of the steel core, the transient current may be several times higher than the peak value of the initial current due to the x-ray tube due to h it requires variable switching energy.
    The purpose of the invention is to increase efficiency, i.e., under varying switching conditions, it is necessary to provide high impulse power transmission while meeting the requirements of both modes without unnecessarily increasing switching losses in a steady state, while the impact load of the thyristors of the circuit is maintained within the allowable dynamic loads
    The goal is achieved by supplying a high-power diagnostic X-ray unit with an inverter unit connected to a DC source connected to the output of an inverter regulating transformer, to which a main high-voltage transformer and a high-voltage rectifier connected to at least one are connected. an x-ray tube, a control unit connected to an inverter unit, which is made according to a bridge circuit consisting of four thyristors, four switching capacitors, four return diodes, and connected to the power buses through inductively coupled switching inductors, parallel to one of the thyristors, a branch is included, consisting of a series-connected fifth thyristor, a diode and an active resistor or two-pole with inductive impedance, and between the common point A fifth thyristor, a diode and a power bus included an additional damping capacitor.
    Parallel to the inverter unit is a branch consisting of a series-connected additional thyristor, a parallel circuit formed by a damping capacitor charged from an auxiliary power source, and a diode, a second parallel circuit formed by a capacitor, a resistor and a damping inductor.
    The inverter unit provides start-stop operation in which, in high-power mode, an integer number of counted voltage periods is generated at the output, the error of which duration depends only on the accuracy of the oscillator-clock frequency that performs the counting, thereby eliminating the error characteristic of the holding circuit traditional x-ray generators, especially in the range of short exposures.
    Possible breakdowns in high voltage
    5 circuits, overloads and short circuits in the load circuits, as well as a sharp decrease in the supply voltage immediately before the switching of the impulse load can lead to the thyristor switching
    0 in the branches of the inverter, to the overlapping of the conductive state of the thyristors, which causes a short circuit between the power lines of the inverter. In contrast to the known circuits that use fast fuses to protect semiconductors, as a protection against overlapping in the proposed device, the inverter is equipped with an electronic overvoltage and short circuit protection circuit that reliably protects all elements of the X-ray unit even in adverse conditions work. Such effective protection has not yet been used in any known X-ray apparatus.
    In addition, in order to reduce losses in the x-ray mode, which corresponds to almost idle speed, the inverter unit is additionally equipped with an output switch serving to power the inverter unit, it also becomes possible to switch the voltage level without using a mains transformer.
    The DC source of the device proposed, connected to the power supply busbars of the inverter unit, is a composite three-phase rectifier unit, in which
    O three diodes and three thyristors form a known three-phase rectifying bridge circuit, and an additional thyristor switch is connected to the common point of the three diodes, between the other electric circuit and the common point of the bridge thyristors, when the polarity coincides, the shunt diode is turned on. and shunt a diode of the corresponding polarity, the other electrode of which is connected to the neutral wire of the network. A well-known anti-aliasing filter is connected to the common point of the diodes and the thyristor key, as well as to the common point of the thyristors of the bridge, which connects from the throttles and the capacitor battery, and the two poles of the capacitor battery are connected to the inverter supply buses. A composite rectifier unit is also connected to a common control unit .I
    The control part of the device is designed to provide a predetermined program of control signals for the implementation of dual-mode operation of the new thyristor circuit, for operation in the start-stop pulse mode, as well as for the operation of the thyristors of additional circuit parts.
    FIG. 1 is a block diagram of a power device; in fig. 2 is a circuit diagram of a device inverter unit: in FIG. 3 is a schematic diagram of a composite rectifier unit; 4, timing diagrams of an electronic control unit.
    The power supply device contains a three-phase network with a zero wire 1 connected to the bridge rectifier 2 and through the switch 3 of the scanning-pictures modes to the block 4 of the smoothing and accumulation filter, the output of which is connected to the input of the block 5 of the inverter made using a bridge circuit with a start-stop circuit 6 and electronic protection circuit 7 against short circuits and overloads, with the output of the inverter unit 5 through an adjusting transformer 8 (or bypassing it connected to the primary winding of a high-voltage transformer 9, sec The windings of which are connected to the AC input of a high-voltage rectifier 10, also assembled according to a bridge circuit, the output of the latter is connected to the X-ray tube 11. The actual voltage of the tube 11 through the divider 12 is sensed by the electronic control unit 13, which, in accordance with the mode of operation of the device controls thyristors of rectifier 2, switch 3 modes of scanning images, block 5 of the inverter, start-stop. circuit 6 and circuit 7 protection against short circuits.
    . The inverter unit 5 (Fig. 2) consists of thyristors 14-17, diodes 18-21, switching capacitors 22-25, inductively coupled switching inductors 26 and 27, and also additionally contains thyristor 28, diode 29, two-pole 30 for current limiting and the damping capacitor 31, which together, when turned on in parallel to one of the thyristors, for example, 16 forms the start-stop cxeiviy.
    In addition, parallel to the common points of the branches of thyristors 14 and 15, as well as 16 and 17, the inverter unit 5 is supplemented with a sequential string Formed by damping coil 32
    inductance, parallel connection of capacitor 33 and discharge resistor 34, parallel connection of damping capacitor 35 and diode 36 preventing capacitor recharging, charging capacitor 35 with auxiliary power supply 37, and thyristor 38 for protection against short circuits, which in general form the circuit of protection against overloads and short circuits.
    .Inverter unit x-ray apparatus operates as follows.
    After connecting the supply voltage, the thyristor 15 of the bridge and the thyristor 28 of the start-stop circuit 6 (the relative position of the ignition pulses in time is shown in diagrams a-1 and a-3 of Fig. 4) is ignited by the ignition signals of the electronic control unit 13 in the first half-period of the voltage produced. Thus, in the first half-period of operation, the supply voltage is connected to the output of the inverter unit 5 through a two-terminal 30 and a diode 29, protecting the circuit from the formation of a dangerously large initial current. In the next half-period, the ignition signal is supplied to the thyristors 14 and 17 (diagram a-4 and a-5 in Fig. 4), and the energy of the commutator capacitors 23 and 24 through the switching inductances 27 and 26 suppresses the pre-conducting thyristors 15 and 28, and at the output of the inverter 39, the polarity of the voltage changes. In the following half-periods, the thyristors 15 and 16 or 14 and 17 simultaneously conduct the ignition signal, the control of which is shown in diagrams a-2 and a-3 in phi, respectively. 4.
    Due to the limitation of the initial current formed during the transient activation process, the inverter unit 5 is stopped after an even number of half-periods, i.e. at the end of an integer number of full periods of the voltage generated by the inverter, the stop is performed either by a command of the circuit counting the preset holding time or by another stop command to the control unit 13, generating control signals for the thyristors, the fixed time until the end of the current even half cycle, a Stop command signal is received. Under the action of this signal at the beginning of the next odd half-period, the ignition signal is fed only to thyristors 16 and 28 (diagrams a-1
    权利要求:
    Claims (2)
    [1]
    Q and a-2 in FIG. four). Thus, the energy of the extinguishing capacitors 22 and 23 locks all the thyristors, stopping the operation of the inverter unit 5, which returns to the initial state, i.e. all five thyristors 14-17 and 28 are waiting for the next exposure in the locked state. With the help of the start-stop circuit 6, it is possible to provide switching of the initial transient overcurrent, as well as stopping the inverter unit 5 under load. The circuit 7 of the electronic protection against short circuits and overloads works as follows. / In the event of a short circuit or overload, the electronic control unit 13 generates a control signal for igniting the thyristor 38, which, using the energy stored in the quenching capacitor 35 charged by the auxiliary power supply unit 37, after ignition takes the load current of unit 5 the inverter and the recharging time of the capacitors 33 and 35, providing a long period of time to restore the locking ability of the thyristors 14 - 17 and 28. At the same time, the electronic control unit 13 prohibits the ignition signals of all five thyristors of the unit 5 inverters, thyristors of bridge rectifier 2, thyristor switch 3 scanning modes-snapshots, and by the end of a long time of locking, provided by the electronic protection circuit 7, all thyristors will be locked. An electron on protection circuit 7 against short circuits and overloads can be made so fast that it protects not only the floor, the conductors from failing under the action of a short circuit, but even prevents the fast-fuses protecting the semiconductors from burning. The composite rectifier unit contains outputs for a three-phase network with a neutral wire 1, a bridge rectifier 2, a switch for 3 modes of scanning-images, a block 4 of a smoothing filter and accumulation. The bridge rectifier 2 (Fig. 3) consists of thyristors 40 - 42. and diodes 43-45, and the switch 3 of the x-ray modes includes a thyristor 46 and a diode 47, while the block 4 of the smoothing and accumulation filter consists of a shunt diode 48, from the smoothing droplets 49 and the storage capacitor 50, the Composite Rectifier unit operates as follows. In the x-ray mode, when the load current is several orders of magnitude lower than the current, in the snapshot mode, the unit operates as a three-phase, three-stroke controlled rectifier, with each of the thyristors 40 - 42 periodically receiving ignition signals at the varying phase angle O, measured relative to the beginning of the negative half-period of the voltage connected to the thyristor of the supply phase. Thus, after switching on, all thyristors 40-42 begin to conduct current with an increasing angle of conductivity (diagram 6-J in Fig. 4) and accumulate capacitor 50 is gradually charged. The charge continues until the voltage level necessary to generate a pre-set voltage is reached. the magnitude of the voltage of the x-ray tube during transmission, in the maximum case, until the amplitude value of the phase voltage of the network is reached at time t. This state continues until the transmission mode is stopped at time t, and the voltage level nor during the transmission, i.e. the corresponding cut-off angle of the thyristors, if necessary, can be adjusted during operation. In the snapshot mode, after turning on the block, the composite rectifier performs a multi-stage workflow according to timing diagrams 6-2 in FIG. 4. in the first stage, up to the moment tj, the rectifier, operating as a three-stroke circuit, thanks to the ignition signals of thyristors 40-42 covering the increasing angle of the conducting state, gradually charges the storage capacitor 50 to the amplitude value of the phase voltage of the supply mains, after which the conduction angle of the thyristors decreases for a short time. In the second stage, starting from the moment t, the thyristor 46 of the switch 3 of the illumination-snapshot mode receives a continuous control signal, while the other half of the bridge consisting of diodes 43-45 is included in the circuit, and the diode 47 is turned off connecting the circuit with zero the wire in the scanning mode. At the moment t onHTb, the program of ignition of thyristors 40-42 begins with expanding pulses, under the action of which the storage capacitor 50 recharges to the amplitude value of the linear voltage of the network. A sintering mode, in which the conduction angle of thyristors 40 - 42 is changed so that under the action of control signals filling the range of phase angles from 30 to 150, the composite rectifier works in the same way as a three-phase six-stroke rectifying bridge. of X-ray power supply images requiring high power continues until it is turned off at the moment. Invention 1. A power supply device for a high-power diagnostic X-ray unit containing an inverter unit is connected connected to the DC source, connected to the output of the inverter is an adjustment transformer, to which the main high-voltage transformer and the high-voltage rectifier connected to at least one X-ray tube, a control unit connected to the inverter unit, which is bridged, are connected circuit consisting of four thyristors, four switching capacitors, four return diodes, and is connected to the power supply buses through inductively connected switching inductors, differing in So that with the purpose of growing
    The efficiency, parallel to one of the thyristors, is a branch consisting of. series-connected fifth thyristor, diode and active resistor or two-pole with inductive impedance, and an additional damping capacitor is connected between the common point of the fifth thyristor, diode and the power bus.
    [2]
    2. The device according to claim 1, wherein the connection is made so that, parallel to the inverter unit, a branch is included, consisting of a series-connected additional thyristor, a parallel circuit formed by the quenching capacitor, charged from an auxiliary source, and a diode a second parallel circuit formed by a capacitor, a resistor, and a damped inductance coil.
    Sources of information taken into account in the examination
    1.Patent of France 2072360, CL. H 03 K 17/00, 10.29.71.
    2. The patent of France 2073054, CL. H 05 G -1/00, 10.29.71.
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    同族专利:
    公开号 | 公开日
    DD142785A1|1980-07-09|
    HU176291B|1981-01-28|
    DE2913622A1|1979-10-18|
    US4259581A|1981-03-31|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3294299A|1965-09-29|1966-12-27|Bernice B Brennan|Safety devices|
    US3428809A|1966-08-18|1969-02-18|Gen Electric|Scr circuit for terminating an x-ray exposure at a precise point|JPH0410316B2|1982-10-04|1992-02-24|
    US4517472A|1983-07-06|1985-05-14|The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration|High voltage power supply|
    JPS6196700A|1984-10-18|1986-05-15|Toshiba Corp|X-ray apparatus|
    US5111493A|1988-11-25|1992-05-05|Wisconsin Alumni Research Foundation|Portable X-ray system with ceramic tube|
    DE19724931A1|1997-06-12|1998-12-17|Philips Patentverwaltung|Power supply unit with a pulse duration modulated inverter, in particular for an X-ray generator|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    HU78ME2156A|HU176291B|1978-04-05|1978-04-05|Powerful diagnostic x-ray apparatus operated with thyristor current converter|
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