RU2506625C1 - Device for automated control of semiconductor elements of bridge rectifier - Google Patents

Abstract

FIELD: physics; control.SUBSTANCE: the invention pertains to electrical measurement techniques. Disclosed is a device having a power supply, outputs of which are respectively connected to the first input of a bridge rectifier and the input of a magnetic field strength sensor, the first and second outputs of which are respectively connected to the second input of the bridge rectifier and the input of an amplifier; the output of the amplifier is connected to the input a band-pass filter; a logic unit a bridge rectifier control unit, the first and second inputs of which are respectively connected to the first and second outputs of the logic unit, and the first and second control outputs of the bridge rectifier control unit are respectively connected to the first and second control inputs of the bridge rectifier; wherein the device further includes a threshold unit and a comparator unit, wherein the input and output of the threshold unit are respectively connected to the output of the band-pass filter and the first input of the logic unit, the second input of which is connected to the output of the comparator unit, the input of which is connected to the output of the amplifier; the first and second outputs of the bridge rectifier control unit are respectively connected to the first and second indicator of the technical state of the bridge rectifier.EFFECT: designing an apparatus for automated control of elements of a bridge rectifier, both a diode bridge rectifier and a thyristor bridge rectifier, which eliminates the effect of faults relating to "rapture" and "breakdown" of semiconductor elements of a bidiagonal bridge on operating capacity of the bridge rectifier without changing power to the load.5 cl, 7 dwg

Description

The invention relates to the field of electrical engineering and can be used in power supplies for an automated transition to a backup semiconductor element of a bridge rectifier in the event of technical situations in the rectification circuit associated with a “break” or “breakdown” of semiconductor elements.

A device for monitoring semiconductor devices that are part of the rectifier, connected to a controlled semiconductor device using probes, which monitors the operating modes and determines the health of the device by evaluating the response of the semiconductor device to the stimulating effect in the form of rectangular pulses following from a special generator [Markin V .AT. et al. Technical Diagnostics of Valve Converters / V.V. Markin, V.N. Mironov, S.G. Obukhov. - M .: Energoatomizdat, 1985].

A disadvantage of the known analogue is the relatively low efficiency of control, which is due to the need to provide a contact connection of the controlling device to the control object - a semiconductor device.

A device for non-contact monitoring of semiconductor elements of single-phase and three-phase bridge rectifiers [A.G. Sukiyazov et al. A device for non-contact monitoring of semiconductor elements of single-phase and three-phase bridge rectifiers according to patent RU PM No. 66820, 2007]. The device contains a magnetic field strength sensor (DNMP) located near the rectifier transformer, a sensor signal amplifier and a bandpass filter (PF) tuned to a frequency of 2ω (ω is the frequency of the supply voltage rectifier), the output of which is connected to the logical part of the device, which, depending from the magnitude of the amplitude of the output signal of the filter, generates a signal about the technical condition of the semiconductor elements on the corresponding indicators.

The disadvantage of this device is the relatively high probability of obtaining inaccurate data on the technical condition of the control object, this is due to the need for preliminary orientation of the sensitivity axis of the magnetic field sensor relative to the control object.

A device for non-contact determination of the technical condition of thyristors of a power source [A.G. Sukiyazov and others. A device for non-contact determination of the technical state of thyristors of a power source according to patent RU No. 2185632, 2002]. The device comprises an external magnetic field measuring transducer (sensor), an amplifier, two phase detectors, a control phase generating device, two level forming amplifiers, an information logical processing device and an information display device.

The disadvantages of the device are the low reliability of the device due to the large number of elements and functional relationships between them, the complexity of the algorithm for obtaining information, as well as the dependence of the shape of the output signal of the sensor (hence, the result of the device as a whole) on the orientation of its sensitivity axis and the lack of influence the output voltage of the power source in case of failure of the controlled thyristors.

The closest analogue (prototype) in terms of technical essence to the claimed device is the known device for automated control of a bridge thyristor rectifier, which is used for contactless automated control of the average rectified voltage of a bridge thyristor rectifier in the event of a fault in the rectification circuit associated with a “break” or “breakdown” thyristors [Sukiyazov A.G., Prosyannikov B.N., Prosyannikov GB The device for automated control of a thyristor bridge rectifier according to patent RU No. 2392654, IPC G05F 5/00, Н02М 7/12, G01R 31/02, published on 06/20/2010, Bulletin No. 17].

The known device for automated control of a thyristor bridge rectifier consists of a power source (IP), the output of which is connected respectively to the input of the magnetic field strength sensor (DNMP), the first and second outputs of which are connected respectively to the input of the sensor signal amplifier (US) and the thyristor rectifier (TV) , the output of the DC is connected to a band-pass filter (PF) tuned to a frequency of 2ω (ω is the frequency of the supply voltage rectifier), the first and second outputs of which are connected respectively to the first and second the input of the logic block (LB) containing the first comparator (K1) and the second comparator (K2), the output K1 is connected to the inputs of the logic circuits 2I-NOT and 2I, and the output of the comparator K2 is connected to the second input of the logic circuits 2I-NOT and to the second input thyristor rectifier control system (SUTV), the output of the logic circuit 2I-NOT connected to the second input of the logic circuit 2I. The output of logic circuit 2I is connected to the first input of the SUTW, the output of which is connected to the control electrodes of the thyristors of bridge TV.

The disadvantage of the device selected for the prototype is the narrow scope of its application, since its use is possible only for thyristor bridge rectifiers, as well as in cases of malfunctions such as “breakdown” of the thyristor of the bridge rectification circuit, when using the prototype it is impossible to restore the efficiency of the bridge rectification circuit, which leads to blackout of consumers of electric energy. In addition, the disadvantage of this device is that in the event of a breakdown of the thyristor type of the bridge rectification circuit, it is transformed into a half-wave rectification circuit, the average rectified (output) voltage is halved, and the current flowing in the circuit is significant for only one half-cycle. As a result, the power allocated to the load is halved, which can lead to a loss of operability of consumers of electric energy.

The purpose of the claimed technical solution is to develop a device for the automated control of semiconductor elements of a bridge rectifier, providing the possibility of expanding the scope of its application, namely with both diode and thyristor bridge rectifiers, as well as eliminating the influence of malfunctions such as "open" and "breakdown" of semiconductor elements of a two-diagonal bridge the efficiency of the bridge rectifier, without changing the power allocated to the load.

This goal is achieved by the fact that in the known device for the automated control of semiconductor elements of a bridge rectifier containing a power source, the outputs of which are connected respectively to the first input of the bridge rectifier and the input of the magnetic field sensor, the first and second outputs of which are connected respectively to the second input of the bridge rectifier and the input amplifier, the output of the amplifier is connected to the input of the bandpass filter, the logic unit and the control unit of the bridge rectifier, first the first and second inputs of which are connected respectively to the first and second outputs of the logic block, and the first and second control outputs of the control unit of the bridge rectifier are connected respectively to the first and second control inputs of the bridge rectifier, a threshold block and a comparison block are additionally introduced, the input and output of the threshold block are connected respectively, to the output of the bandpass filter and to the first input of the logic unit, the second input of which is connected to the output of the comparison unit, the input of which is connected to the output of the amplifier , the first and second outputs of the bridge rectifier control unit are connected respectively to the first and second indicators of the technical condition of the bridge rectifier.

The comparison unit consists of the first and second low-pass filters, the outputs of which are connected to the first and second inputs of a two-input operational amplifier, the output of which is the output of the unit, and the inputs of the first and second low-pass filters through the multipolarly switched diodes are combined and are the input of the block.

The logic block consists of the first and second two-input elements “AND” and the element “NOT”, the first input of the first two-input element “AND” is connected to the first input of the second two-input element “AND”, the second input of which is connected to the inverse output of the element “NOT”, the input which is connected to the second input of the first two-input element "And", the first and second inputs of which are respectively the first and second inputs of the block, and the outputs of the first and second two-input elements "And" are respectively the first and second outputs of the unit a.

The bridge rectifier consists of a two-diagonal bridge and a transformer, the secondary windings of which are connected to the first diagonal of the bridge, the load is connected to the second diagonal, two semiconductor elements are connected to each shoulder of the two-diagonal bridge, the cathode terminals of which are connected and connected to the corresponding vertex of the diagonal, and their the anode leads are connected to the corresponding contacts of the on-off relay, the leads of the primary winding of the transformer are inputs of a bridge rectifier, and I control s inputs DIP switch belonging to opposite shoulders dual-diagonal of the bridge, are combined in pairs and are the respective control inputs of the bridge rectifier.

The bridge rectifier control unit consists of the first and second electromagnetic relays, each of which is equipped with make contacts, the control inputs of the electromagnetic relays are the control outputs of the unit and are connected to the cathodes of the corresponding diodes, the anodes of which are the inputs of the unit, and the inputs of the electromagnetic relays are the outputs of the unit.

Thanks to a new set of essential features due to the introduction of a threshold block and a comparison block, which simultaneously compares in absolute terms the average values of the positive and negative half-periods of the output voltage from the magnetic field strength sensor, the formation of a control signal for switching a faulty pair of semiconductor elements of a two-diagonal bridge to the reserve. This makes it possible to expand the scope of the claimed device, as well as eliminating the influence of faults such as “open” and “breakdown” of the semiconductor elements of a two-diagonal bridge on the operability of a bridge rectifier, without changing the power allocated to the load.

The claimed device for the automated control of semiconductor elements of a bridge rectifier is illustrated by drawings, which show:

Figure 1 - General block diagram of a device for automatic control of semiconductor elements of a bridge rectifier;

Figure 2 - General block diagram of a bridge rectifier;

Figure 3 is a block diagram of a comparison unit;

Figure 4 is a block diagram of a logical block;

5 is a block diagram of a control unit bridge rectifier;

6 is a block diagram of a diode bi-diagonal bridge;

7 is a structural diagram of a thyristor bi-diagonal bridge.

The claimed device for the automated control of semiconductor elements of a bridge rectifier, shown in (Fig. 1), consists of a power supply 1 (IP), the outputs of which are connected respectively to the first input 3.1 of the bridge rectifier 3 (MB) and the input of the magnetic field strength sensor 2 (DNMP) , the first and second outputs of which are connected respectively to the input 3.2 MB 3 and the input of the amplifier 4 (US), the output of US 4 is simultaneously connected to the inputs of the bandpass filter 5 (PF) and the comparison unit 7 (BS), the input and output of threshold block 6 (PB ) connected respectively, to the output of the PF 5 and the first input 8.1 of the logical unit 8 (LB), the second input 8.2 LB 8 is connected to the output of the BS 7, the inputs 9.1 and 9.2 of the control unit of the bridge rectifier 9 (BUMV) are connected respectively to the first and second outputs of the LB 8 and the first and second control outputs of the paper 9 are connected respectively to the first 3.3 and second 3.4 control inputs of the MB 3, the first 9.3 and second 9.4 outputs of the paper 9 are connected to 10 and 11 indicators of the technical condition of MB 3, respectively.

DNMP 2 is designed to generate a signal proportional to the magnitude of the current flowing in the conductive wires between IP 1 and MB 3. DNMP 2 is placed in a microinductive solenoid hub from several turns of the conductive wire to the primary winding of transformer MB 3 wound on a dielectric cylindrical tube.

A variant of constructing DNMP 2 is known and described, for example, in the patent for invention RU No. 2392654 C2 in figure 1.

MB 3, the structural diagram of which is shown in figure 2, is designed to convert AC to DC. MV 3 consists of a two-diagonal bridge 3.2 (DDM) and a transformer 3.1, the outputs of the secondary winding of which are connected to the first diagonal of the DDM 3.2, the second diagonal of which is connected to the load, two semiconductor elements are connected to each arm of the DDM 3.2, the cathode terminals of which are connected and connected to the corresponding diagonal vertex, and their anode terminals are connected to the corresponding contacts of the on-off relay, the terminals of the primary winding of the transformer are MB 3 inputs, and the control inputs of the on-off relays related to to the opposite shoulders DDM 3.2, are pairwise combined and are the corresponding control inputs MB 3.

MB schemes are known and described, for example, in the book by A.S. Kasatkin and M.A. Perekalin. Electrical Engineering (Energoatomizdat, 1959, p. 152, Fig. 10-19). MB 3 can be performed both on the diode and on the thyristor bi-diagonal bridge, Fig.6 and Fig.7, respectively. In DDM 3.2, shown in FIG. 6, commercially available domestic models 2D677A-5 or an imported analogue 1N4004 can be used as diodes. As on-off relays K1-K4 can be used commercially available domestic relay models 5P19.10TM1-10-80 V2 or an imported analogue of D2410. In DDM 3.2, shown in Fig.7, as a thyristor can be used commercially available domestic models KU 111A or 2U202E. As on-off relays K1-K4, commercially available domestic models of the relay 5P19.10TS1-10-80-V1 or KR 293KP4A can be used.

US 4 is designed to amplify the signal from DNMP 2 to the value necessary for the operation of the circuit. US 4 can be implemented on an operational amplifier. As an operational amplifier can be used commercially available domestic models 154UD401BS or 140UD20A.

PF 5 is designed to extract from the spectrum of the amplitudes of the output signal DNMP 2 even spectral component 2ω. PF 5 can be performed on any standard passive PF circuit using commercially available electronic components (resistors, capacitors). A specific implementation scheme for PF 5 will be determined by the fact that it must be tuned to a frequency of 2ω (ω is the frequency of the supply voltage 3 MB).

PB 6 is designed to form a reference level of the signal amplitude of the second harmonic component of the voltage supplying MB 3 to the output signal from DNMP 2. The reference level of PB 6 is tuned to the signal amplitude from the PF 5 output of the corresponding technical situation “break” of the DDM 3.2 semiconductor element. In the technical situation, the “breakdown” of the semiconductor element DDM 3.2, the signal amplitude from the output of the PF 5 exceeds the value of the signal amplitude of the corresponding technical situation, the “breakdown” of the semiconductor element DDM 3.2 (RU Patent ПМ No. 66820 of 2007), so PB 6 will work in the event of any of the listed technical situations. PB 6 can be implemented on a high-speed comparator with a Schmit trigger connected in series. Commercially available domestic models 1481CA1 can be used as a high-speed comparator; commercially available domestic models of the 564TL 2V series can be used as a Schmit trigger.

BS 7, the structural diagram of which is shown in Fig. 3, is designed to generate a signal corresponding to the number of a pair of arms (a pair of semiconductor elements) of DDM 3.2, in which a malfunction of the "open" or "breakdown" type of a semiconductor element DDM 2 was realized by receiving a signal from DNMP 2, dividing this signal through differently connected diodes 7.1 and 7.2 into two components, processing them on low-pass filters 7.3 and 7.4, respectively, and comparing modulo the average value of the processed signal components with DNMP 2 among themselves on a two-input operational amplifier 7.5 (DOU).

BS 7 consists of the first and second low-pass filters, 7.3. and 7.4, respectively, whose outputs are connected to the first and second inputs of the two-input operational amplifier 7.5, the output of which is the output of the unit, and the inputs 7.3 and 7.4 through the diodes 7.1 and 7.2 connected in different polarity are combined and are the input of the unit. Commercially available domestic models KD 243V can be used as diodes, commercially available domestic models 1478 FN1U or an imported analogue of MAX 293 EPA can be used as low-frequency filters, commercially available domestic models 140UD 20A or imported can be used as a two-input operational amplifier analogue of LM 124J.

LB 8, the structural diagram of which is shown in figure 4, is designed to generate a signal about the occurrence of faults of the type "break" or "breakdown" in the corresponding pair of semiconductor elements DDM 3.2. LB 8 consists of the first and second two-input elements "AND" 8.1 and 8.2, respectively, and the element "NOT" 8.3, the first input of the two-input element "AND" 8.1 is connected to the first input of the second two-input element "AND" 8.2, the second input of which is connected to the inverse output element "NOT" 8.3, the input of which is connected to the second input of the first two-input element "AND" 8.1, the first and second inputs of which are respectively the first and second inputs of the block, and the outputs of the first and second two-input elements "AND" 8.1 and 8.2 are respectively the first and tue the other outputs of the block. As two-input elements 8.1 and 8.2, commercially available domestic models 1533 LI 1 or imported analogs SN 74 AMC can be used, as element 8.3, commercially available domestic models 1533 LN 1 or imported analogs SN 7406N can be used.

BUMV 9, the structural diagram of which is shown in Fig. 5, is intended to generate a control signal for switching the corresponding pair of semiconductor elements DDM 3.2 to the reserve. BUMV 9 consists of the first and second electromagnetic relays 9.1 and 9.2, each of which is equipped with closing contacts K1 and K2, respectively, the control inputs of the electromagnetic relays are the control outputs of the BUMV 9 and are connected to the cathodes of the corresponding diodes 9.3 and 9.4, the anodes of which are the inputs of the BUMV 9, moreover, the inputs of the electromagnetic relays are the output of the BUMV 9. Serially produced domestic models 2D203 A1 can be used as diodes, commercially available edema can be used as electromagnetic relays Natural models 5P19.10TS1-10-80-B1.

The outputs 9.3 and 9.4 of the paper 9 are connected respectively to 10 and 11 indicators of the technical condition of MB 3.

As indicators 10 and 11 of the technical condition of MB 3 can be used commercially available domestic models of LEDs of the AL 307 AM series, connected through a current-limiting resistor of 1 kOhm.

The claimed device operates as follows.

If MB 3 operates in the nominal operating mode and all its elements are operational, then only the odd spectral components 3ω, 5ω, 7ω, ... that are multiples of the main frequency will be present in the amplitude spectrum of the output signal DNMP 2 placed in the solenoid hub on the current-conducting wires supply voltage rectifier ω. The shape of the output signal DNMP 2 will be symmetrical with respect to the abscissa axis.

In case of a change in the technical condition of the DDM 3.2 semiconductor elements (breakdowns of the type “break” or “breakdown”), the signals of even spectral components 2ω, 4ω, 6ω that are multiples of the fundamental frequency ω additionally appear in the amplitude spectrum of the output signal of DNMP 2 current. The waveform in this case loses its symmetry, that is, the area of the positive (or negative - depending on the number of the pair of arms of the DDM 3.2 in which the malfunction occurred) of the half-period becomes significantly different from the area of the negative half-period (or the positive half-period).

Thus, the fact of the appearance of even spectral components in the amplitude spectrum of the output signal of DNMP 2 of the current flowing in the MB 3 circuit (including in the current-conducting wires) will be an unambiguous evidence of the occurrence of malfunctions of the “open” or “breakdown” type of semiconductor elements in DDM 3.2 leading to a deterioration in the quality of the output voltage MB 3, and the subsequent occurrence of emergency operation, which could lead to failure of both the rectifier itself and the devices connected to it. In addition, to determine the shoulder number of the rectification bridge circuit (semiconductor element number) in which an “open” or “breakdown” occurred, a modulo comparison of the average values of the positive and negative half-periods of the output voltage of the magnetic field strength sensor is required.

Similar physical processes will occur in a three-phase bridge rectifier.

During the operation of MB 3, the current flowing in the current-carrying wires creates a magnetic field, the strength of which in the microinductive inductance solenoid hub is uniquely related to the current strength in DDM 3.2. Thus, DNMP 2 generates a signal proportional to the magnitude of the current flowing in DDM 3.2.

In the event that the semiconductor DDM 3.2 is operational, the signal from the DNMP 2 output after amplification is fed to PF 5, where its further conversion is terminated due to the absence of a signal component with a frequency of 2ω in it, as well as to BS 7, where the diodes are connected through different polarity 7.1 and 7.2, the signal is fed to low-pass filters 7.3 and 7.4, respectively, the output signals of which in this case are not enough to trigger the DOW 7.5. LB 8 doesn’t work at the same time; signals are not received at BUMV 9.

If a fault occurs in the DDM 3.2 semiconductor element of the “open” or “breakdown” type, the even spectral component that appears in the output signal with a frequency of 2ω passes through the PF 5 and goes to the input of the threshold unit 6. The signal from the output of the PB 6 goes to the first input of the logic elements 8.1 and 8.2 LB 8. At the same time, due to the asymmetry in the shape of the output signal of DNMP 2 relative to the abscissa axis, the output signal of one of the low-pass filters 7.3 or 7.4 (depending on the number of arm pairs of the DDM 3.2, in which be) acquires a different value from another that is fixed DOW 7.5. The signal from the output of the DOU 7.5 (corresponding to the number of the pair of shoulders in which the malfunction occurred) is fed to the second input of the logic element 8.1 LB 8 and through the inverter to the second input of the logical element 8.2 LB 8. The signal from the triggered logic element 8.1 or 8.2 LB 8 to switch the corresponding a pair of shoulders (a pair of semiconductor elements) DDM 3.2 arrives at BUMV 9, which directly generates a control signal for switching a pair of shoulders (a pair of semiconductor elements) to the reserve. For example, in the event of a breakage or breakdown of a semiconductor element 3.2.1 DDM 3.2, the logic element 8.1 LB 8 generates a signal at the first output of the LB 8, which is fed to the first input 9.1 of the BMS 9, this signal is fed to the electromagnetic through the diode 9.1 relay K1 BUMV 9, which closes the contact K1. BUMV 9 provides a control signal to the input 3.3 MB 3, as a result, the contacts K1 and K4 of the on-off relays K1 and K4 are switched from the anode terminals of the semiconductor elements 3.2.1 and 3.2.5 of the DDM 3.2 to the anode terminals of the reserve semiconductor elements 3.2.2 and 3.2. 6 DDM 3.2, respectively. At the same time, a signal is generated from the output 9.3 of the paper 9 on the indicator 10 of the technical condition of MB 3.

In the event of a breakage or breakdown of a semiconductor element in another pair of DDM 3.2 arms, for example, a semiconductor element 3.2.3, the logic element 8.2 LB 8 generates a signal at the second output of the LB 8, which is fed to the second input 9.2 of the BMS 9, This signal through the diode 9.2 enters the electromagnetic relay K2 BUMV 9, which closes the contact K2. BUMV 9 provides a control signal to the input 3.4 MB 3, as a result, the contacts K2 and K3 of the on-off relays K2 and K3 are switched from the anode terminals of the semiconductor elements 3.2.3 and 3.2.7 of the DDM 3.2 to the anode terminals of the reserve semiconductor elements 3.2.4 and 3.2. 8 DDM 3.2, respectively.

At the same time, a signal is generated from the output 9.4 of the paper 9 on the indicator 11 of the technical condition of MB 3.

Thus, the claimed device has a significant positive effect, consisting in the use of this device with both diode and thyristor bridge rectifiers, eliminating the influence of faults such as "open" and "breakdown" of semiconductor elements of a two-diagonal bridge on the efficiency of the bridge rectifier, without changing the power allocated load, i.e. maintaining the operability of electricity consumers.

Claims (5)

1. A device for automated control of semiconductor elements of a bridge rectifier, containing a power source, the outputs of which are connected respectively to the first input of the bridge rectifier and the input of the magnetic field sensor, the first and second outputs of which are connected respectively to the second input of the bridge rectifier and the input of the amplifier, the output of the amplifier is connected to the input of the bandpass filter, the logic unit and the control unit of the bridge rectifier, the first and second inputs of which are connected respectively about to the first and second outputs of the logic unit, and the first and second control outputs of the bridge rectifier control unit are connected respectively to the first and second control inputs of the bridge rectifier, characterized in that a threshold block and a comparison unit are additionally introduced, the input and output of the threshold block are connected respectively to the output of the bandpass filter and to the first input of the logic block, the second input of which is connected to the output of the comparison unit, the input of which is connected to the output of the amplifier, the first and second outputs of the block Control bridge rectifier are respectively connected to first and second indicators of technical state of the bridge rectifier. 2. The device according to paragraph 1, characterized in that the comparison unit consists of the first and second low-pass filters, the outputs of which are connected to the first and second inputs of a two-input operational amplifier, the output of which is the output of the unit, and the inputs of the first and second low-pass filters through different polarity The included diodes are combined and are the input of the unit. 3. The device according to claim 1, characterized in that the logic unit consists of the first and second two-input elements “AND” and the element “NOT”, the first input of the first two-input element “AND” is connected to the first input of the second two-input element “AND”, the second input which is connected to the inverse output of the element "NOT", the input of which is connected to the second input of the first two-input element "And", the first and second inputs of which are respectively the first and second inputs of the block, and the outputs of the first and second two-input elements "And" are I, respectively, the first and second outputs of the block. 4. The device according to claim 1, characterized in that the bridge rectifier consists of a two-diagonal bridge and a transformer, the outputs of the secondary winding of which are connected to the first diagonal of the bridge, to the second diagonal of which a load is connected, two semiconductor elements, cathode, are included in each arm of the two-diagonal bridge the conclusions of which are connected and connected to the corresponding vertex of the diagonal, and their anode terminals are connected to the corresponding contacts of the on-off relay, the conclusions of the primary winding of the transformer are odes bridge rectifier and the control inputs of the two-position switch belonging to the opposing shoulders dual-diagonal bridge pairs are combined and the respective control inputs of the bridge rectifier. 5. The device according to claim 1, characterized in that the bridge rectifier control unit consists of the first and second electromagnetic relays, each of which is equipped with make contacts, the control inputs of the electromagnetic relays are the control outputs of the unit and are connected to the cathodes of the corresponding diodes, the anodes of which are inputs block, and the inputs of electromagnetic relays are the outputs of the block.

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