A device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output

Abstract

The present invention discloses a device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output, including a pulse phase shifting device and a plurality of rectifier bridges connected in parallel. The number of pulse phase shifting devices corresponds to the number of rectifier bridges, and the output ends of the pulse phase shifting devices are respectively connected to the trigger pulse input ends of the thyristors on the three phase lines of the rectifier bridges. The pulse phase shifting device is used to change the trigger angle of the thyristor. In the present invention, a pulse phase shifting device is connected to the thyristor trigger pulse input end on the three phase lines of each rectifier bridge corresponding to the plurality of rectifier bridges connected in parallel, and the output voltage of the rectifier bridge is adjusted by changing the trigger angle of the thyristor. There is no need to connect some electronic devices that need to be replaced, which reduces the cost and has a good current-balanced effect.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output. Background Art

[0002] When the output rated current of a single rectifier bridge cannot meet the unit operation requirements, multiple rectifier bridges are often required to be used in parallel. However, when multiple thyristor rectifier bridges are operated in parallel, the most likely problem is poor current sharing between the rectifier bridges. The main factors causing the current sharing problem are inconsistent thyristor trigger signals and uneven electrical distances between rectifier bridges.

[0003] In order to solve the problem of poor current sharing performance between rectifier bridges, the methods commonly used in the prior art are: 1. Try to match the working characteristics of the thyristor; 2. Use resistors to share current; 3. Use series reactors to share current. Among them, when choosing to match the thyristor parameters, it is more laborious to select the match, and after running for a period of time, when the thyristor is damaged and replaced, it is not easy to get a device with the same performance as the original device, resulting in poor implementation effect. When using resistors and reactors to share current, it is not easy to achieve current sharing, and when using reactors, it also increases equipment costs and energy consumption.

[0004] It can be seen that the existing method has a high cost and cannot guarantee a good current sharing effect. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a device for realizing parallel operation of multiple rectifier bridge cabinets and current equalization output, which has a good current equalization effect while maintaining low cost.

[0006] In order to solve the above problems, the solution adopted by the present invention is:

[0007] A device for realizing parallel operation of multiple rectifier bridge cabinets and equal current output, comprising a pulse phase shifting device and multiple rectifier bridges connected in parallel;

[0008] The number of the pulse phase shifting devices corresponds to the number of the rectifier bridges, and the output ends of the pulse phase shifting devices are respectively connected to the thyristor trigger pulse input ends on the three phase lines of the rectifier bridges;

[0009] The pulse phase shifting device is used to change the trigger angle of the thyristor.

[0010] To sum up, the beneficial effects of the present invention are: providing a device for realizing parallel operation of multiple rectifier bridge cabinets and current equalization output, connecting a pulse phase shifting device to the thyristor trigger pulse input terminal on the three phase lines of each rectifier bridge corresponding to the multiple rectifier bridges connected in parallel, and adjusting the output voltage of the rectifier bridge by changing the trigger angle of the thyristor, without the need to connect some electronic devices that need to be replaced, thereby reducing costs and having a good current equalization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic diagram of the connection between a rectifier bridge and a pulse phase shifting device of a device for realizing parallel operation of multiple rectifier bridge cabinets and current equalization output according to an embodiment of the present invention;

[0012] Figure 2 A system block diagram of a pulse phase shifting device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to an embodiment of the present invention;

[0013] Figure 3 This is a circuit connection diagram of a pulse phase shifting device of an apparatus for realizing parallel operation of multiple rectifier bridge cabinets and current equalization output in an embodiment of the present invention.

[0014] Description of labels:

[0015] 1. Pulse phase shift device; 2. Rectifier bridge; 3. Comparator output module; 4. Adjustable delay module; 5. Adjustable voltage module; 6. Power supply module; 7. Optocoupler isolation module;

[0016] C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor;

[0017] D1, diode;

[0018] K1, first switch; K2, second switch; K3, third switch; K4, fourth switch;

[0019] R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; R12, twelfth resistor; R13, thirteenth resistor;

[0020] U1, operational comparator; U2, optocoupler. DETAILED DESCRIPTION

[0021] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0022] Please refer to Figures 1 to 3, a device for realizing parallel operation of multiple rectifier bridges 2 cabinets and equal current output, comprising a pulse phase shifting device 1 and multiple rectifier bridges 2 connected in parallel;

[0023] The number of the pulse phase shifting devices 1 corresponds to the number of the rectifier bridges 2, and the output ends of the pulse phase shifting devices 1 are respectively connected to the trigger pulse input ends of the thyristors on the three phase lines of the rectifier bridge 2;

[0024] The pulse phase shifting device 1 is used to change the trigger angle of the thyristor.

[0025] From the above description, it can be seen that the beneficial effects of the present invention are: providing a device for realizing parallel operation of multiple rectifier bridges 2 cabinets and current equalization output, connecting a pulse phase shifting device 1 to the thyristor trigger pulse input end on the three phase lines of each rectifier bridge 2 on the multiple rectifier bridges 2 connected in parallel, and adjusting the output voltage of the rectifier bridge 2 by changing the trigger angle of the thyristor. It does not need to connect some electronic devices that need to be replaced, thus reducing costs and having a good current equalization effect.

[0026] Furthermore, the pulse phase shifting device 1 includes a comparator output module 3, an adjustable delay module 4, an adjustable voltage module 5 and a power supply module 6;

[0027] The input end of the adjustable delay module 4 is used for external pulse signal, the output end of the adjustable delay module 4 is connected to the positive phase input end of the comparator output module 3, the output end of the adjustable voltage module 5 is connected to the negative phase input end of the comparator output module 3, and the output end of the comparator output module 3 is respectively connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge 2;

[0028] The power supply module 6 is connected to the power supply end of the adjustable delay module 4 and the power supply end of the adjustable voltage module 5 respectively.

[0029] From the above description, it can be seen that the adjustable delay module 4 is used to delay and phase-shift the pulse signal as the positive phase input of the comparator output module 3. The adjustable voltage module 5 and the power supply module 6 provide an adjustable voltage output as the negative phase input of the comparator output module 3, so as to flexibly change the output signal of the comparator output module 3, thereby making the trigger angles of the thyristors on the three phase lines of the rectifier bridge 2 change to different degrees to meet different current sharing requirements.

[0030] Further, the adjustable delay module 4 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first switch K1, a first capacitor C1, a second capacitor C2 and a third capacitor C3;

[0031] One end of the first resistor R1 is connected to the power module 6, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is simultaneously connected to the positive input end of the comparator output module 3, one end of the third resistor R3, one end of the first capacitor C1 and one end of the first switch K1, the other end of the first switch K1 is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is connected to one end of the third capacitor C3, and the other end of the three resistors R3 is connected to one end of the fourth resistor R4;

[0032] The other end of the second capacitor C2, the other end of the third capacitor C3 and the other end of the fourth resistor R4 are all grounded, and the connection between the first resistor R1 and the second resistor R2 is used for externally connecting a pulse signal.

[0033] From the above description, it can be seen that the adjustable delay module 4 is mainly an RC loop composed of a resistor and a capacitor. By changing the switch state of the first switch K1 to adjust the loop parameters, the positive input of the comparator output module 3 obtains voltages of different magnitudes.

[0034] Furthermore, a diode D1 is connected between the first resistor R1 and the second resistor R2;

[0035] The anode of the diode D1 is connected to an end of the first resistor R1 away from the power module 6, and the cathode of the diode D1 is connected to an end of the second resistor R2 away from the comparator output module 3;

[0036] The connection point between the second resistor R2 and the cathode of the diode D1 is used for externally connecting a pulse signal.

[0037] From the above description, it can be known that a diode D1 is connected between the first resistor R1 and the second resistor R2, so that the pulse signal can flow to the power module 6 through the first resistor R1, which has a protective effect.

[0038] Furthermore, the adjustable voltage module 5 includes a fifth resistor R5 and a variable resistor network;

[0039] One end of the fifth resistor R5 is connected to the power module 6, and the other end of the fifth resistor R5 is simultaneously connected to the inverting input end of the comparator output module 3 and the first common end of the variable resistor network;

[0040] The second common terminal of the variable resistance network is grounded.

[0041] From the above description, it can be seen that the adjustable voltage module 5 uses the fifth resistor R5 and the variable resistor network as a voltage divider circuit, and changes the voltage actually output by the adjustable voltage module 5 to the inverting input terminal of the comparator output module 3 by adjusting the resistance of the variable resistor network. The adjustment method is simple and flexible to use.

[0042] Further, the variable resistor network includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a second switch K2, a third switch K3, and a fourth switch K4;

[0043] One end of the sixth resistor R6 is simultaneously connected to the other end of the fifth resistor R5, the inverting input end of the comparator output module 3, one end of the second switch K2, one end of the third switch K3 and one end of the fourth switch K4, the other end of the second switch K2 is connected to one end of the seventh resistor R7, the other end of the third switch K3 is connected to one end of the eighth resistor R8, and the other end of the fourth switch K4 is connected to one end of the ninth resistor R9;

[0044] The other end of the sixth resistor R6, the other end of the seventh resistor R7, the other end of the eighth resistor R8 and the other end of the ninth resistor R9 are all grounded.

[0045] From the above description, it can be seen that the variable resistor network is mainly composed of a parallel network composed of multiple resistors and switches. The number of parallel resistors is adjusted by changing the switching state of each switch, so that the actual equivalent resistance value of the circuit changes and the size of the voltage division changes.

[0046] Further, the comparator output module 3 includes an operational comparator U1, a fourth capacitor C4, a tenth resistor R10 and an eleventh resistor R11;

[0047] The non-phase input terminal of the operational comparator U1 is simultaneously connected to one end of the fourth capacitor C4, one end of the eleventh resistor R11 and the output end of the adjustable delay module 4, the inverting input terminal of the operational comparator U1 and the output end of the adjustable voltage module 5 are connected to one end of the tenth resistor R10, the output end of the operational comparator U1 is simultaneously connected to the other end of the fourth capacitor C4 and the other end of the tenth resistor R10, and the other end of the eleventh resistor R11 is connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge 2.

[0048] From the above description, it can be seen that the tenth resistor R10 can increase the stability of the system and can adjust the gain; the output voltage of the adjustable delay module 4 and the output voltage of the adjustable voltage module 5 are compared and output by the operational comparator U1 with a feedback network composed of the fourth capacitor C4 and the eleventh resistor R11, thereby outputting the required trigger pulse, and correspondingly adjusting the trigger angle of the thyristor to the required angle to achieve current sharing, and its waveform change is flexible, the comparison logic is simple, and it is easy to use.

[0049] Furthermore, the pulse phase shifting device 1 further includes an optical coupling isolation module 7;

[0050] The output end of the comparator output module 3 is respectively connected to the trigger pulse input end of the thyristors on the three phase lines of the rectifier bridge 2 through the optical coupling isolation module 7 , and the power supply module 6 is connected to the power supply end of the optical coupling isolation module 7 .

[0051] From the above description, it can be seen that an optocoupler isolation module 7 is connected between the comparator output module 3 and the rectifier bridge 2, which can isolate the input and output of the previous and next stages, effectively control the circuit noise, and increase the stability of the circuit.

[0052] Further, the optical coupling isolation module 7 includes an optical coupler U2, a twelfth resistor R12 and a thirteenth resistor R13;

[0053] The positive input end of the optical coupler U2 is simultaneously connected to one end of the twelfth resistor R12 and one end of the thirteenth resistor R13, and the other end of the twelfth resistor R12 is simultaneously connected to the power module 6 and the other end of the thirteenth resistor R13;

[0054] The negative input end of the optical coupler U2 is connected to the output end of the comparator output module 3, the output end of the optical coupler U2 is connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge 2, and the ground end of the optical coupler U2 is grounded.

[0055] From the above description, it can be seen that the optical coupler U2 of the adjustable voltage module 5 uses optical signals as a transmission medium, has strong anti-interference ability, has no contacts, has a long service life, and can transmit signals in one direction well.

[0056] Furthermore, the optical coupler U2 is a TCET1100 optical coupler U2.

[0057] From the above description, it can be seen that the TCET1100 optical coupler U2 has low transmission delay and good isolation performance.

[0058] The device of the present invention for realizing parallel operation of multiple rectifier bridges 2 cabinets and equalizing current output is suitable for application scenarios when multiple rectifier bridges 2 are used in parallel, and is specifically described below in conjunction with specific embodiments:

[0059] Please refer to Figure 1 and Figure 2 , Embodiment 1 of the present invention is:

[0060] A device for realizing parallel operation of multiple rectifier bridges and two cabinets and equalizing current output, such as Figure 1 As shown, it includes a pulse phase shift device 1 and a plurality of rectifier bridges 2 connected in parallel. The number of pulse phase shift devices 1 corresponds to the number of rectifier bridges 2, and the output end of the pulse phase shift device 1 is respectively connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge 2; the pulse phase shift device 1 is used to change the trigger angle of the thyristor.

[0061] Specifically, Figure 2 As shown, in this embodiment, the pulse phase shift device 1 includes a comparator output module 3, an adjustable delay module 4, an adjustable voltage module 5, an optical coupling isolation module 7 and a power supply module 6. Among them, the input end of the adjustable delay module 4 is used for external pulse signals, the output end of the adjustable delay module 4 is connected to the positive phase input end of the comparator output module 3, the output end of the adjustable voltage module 5 is connected to the negative phase input end of the comparator output module 3, and the output end of the comparator output module 3 is respectively connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge 2. The power supply module 6 is respectively connected to the power supply end of the adjustable delay module 4 and the power supply end of the adjustable voltage module 5.

[0062] In this embodiment, if Figure 1 and 2 As shown, the three pulse triggering devices are respectively connected to the three rectifier bridges 2 of FLZ1, FLZ2 and FLZ3, and the process of achieving current equalization output is as follows:

[0063] First, the phase line output of each rectifier bridge 2 is detected respectively to find the bridge with the largest or smallest output current.

[0064] Secondly, a pulse signal is connected to the pulse triggering device corresponding to the bridge, and the corresponding trigger angle to be changed is calculated according to the current difference between the bridge and other bridges. By adjusting the module parameters of the adjustable delay module 4 and the adjustable voltage module 5, the comparator output module 3 obtains the corresponding degree of subsequent output;

[0065] Finally, the output of the comparator output module 3 flows to the trigger pulse input terminal of the thyristor on the three phase lines of the rectifier bridge 2, which changes the trigger angle of the thyristor accordingly, thereby changing the output current of the rectifier bridge 2 to achieve current sharing.

[0066] Please refer to Figure 3 , Embodiment 2 of the present invention is:

[0067] A device for realizing parallel operation of multiple rectifier bridges and two cabinets and equalizing current output, based on the above-mentioned embodiment 2, as Figure 3As shown, the adjustable delay module 4 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first switch K1, a first capacitor C1, a second capacitor C2 and a third capacitor C3. Among them, one end of the first resistor R1 is connected to the power module 6, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is simultaneously connected to the positive input end of the comparator output module 3, one end of the third resistor R3, one end of the first capacitor C1 and one end of the first switch K1, the other end of the first switch K1 is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is connected to one end of the third capacitor C3, and the other end of the three resistors R3 is connected to one end of the fourth resistor R4. The other end of the second capacitor C2, the other end of the third capacitor C3 and the other end of the fourth resistor R4 are all grounded, and the connection between the first resistor R1 and the second resistor R2 is used for external pulse signals.

[0068] like Figure 3 As shown, a diode D1 is also connected between the first resistor R1 and the second resistor R2. The anode of the diode D1 is connected to the end of the first resistor R1 away from the power module 6, and the cathode of the diode D1 is connected to the end of the second resistor R2 away from the comparator output module 3. The connection between the second resistor R2 and the cathode of the diode D1 is used for external pulse signal.

[0069] As shown in the figure, the adjustable voltage module 5 includes a fifth resistor R5 and a variable resistor network. One end of the fifth resistor R5 is connected to the power module 6, and the other end of the fifth resistor R5 is simultaneously connected to the inverting input end of the comparator output module 3 and the first common end of the variable resistor network. The second common end of the variable resistor network is grounded.

[0070] Specifically, the variable resistor network includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor, a second switch K2, a third switch K3 and a fourth switch K4. One end of the sixth resistor R6 is simultaneously connected to the other end of the fifth resistor R5, the inverting input end of the comparator output module 3, one end of the second switch K2, one end of the third switch K3 and one end of the fourth switch K4, the other end of the second switch K2 is connected to one end of the seventh resistor R7, the other end of the third switch K3 is connected to one end of the eighth resistor R8, and the other end of the fourth switch K4 is connected to one end of the ninth resistor R9. The other end of the sixth resistor R6, the other end of the seventh resistor R7, the other end of the eighth resistor R8 and the other end of the ninth resistor R9 are all grounded.

[0071] like Figure 3As shown, the comparator output module 3 includes an operational comparator U1, a fourth capacitor C4, a tenth resistor R10 and an eleventh resistor R11. The positive phase input terminal of the operational comparator U1 is simultaneously connected to one end of the fourth capacitor C4, one end of the eleventh resistor R11 and the output end of the adjustable delay module 4, the negative phase input terminal of the operational comparator U1 and one end of the tenth resistor R10 are connected to the output end of the adjustable voltage module 5, and the output end of the operational comparator U1 is simultaneously connected to the other end of the fourth capacitor C4, the other end of the tenth resistor R10, the other end of the eleventh resistor R11 and the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge 2.

[0072] As shown in the figure, the optical coupling isolation module 7 includes an optical coupler U2, a twelfth resistor R12 and a thirteenth resistor R13. The positive input end of the optical coupler U2 is simultaneously connected to one end of the twelfth resistor R12 and one end of the thirteenth resistor R13, and the other end of the twelfth resistor R12 is simultaneously connected to the power module 6 and the other end of the thirteenth resistor R13. The negative input end of the optical coupler U2 is connected to the output end of the comparator output module 3, the output end of the optical coupler U2 is connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge 2, and the ground end of the optical coupler U2 is grounded. Optionally, the optical coupler U2 selects TCET1100 optical coupler U2.

[0073] In summary, the present invention discloses a device for realizing parallel operation of multiple rectifier bridge cabinets and current equalization output. A pulse phase shifting device is connected to the thyristor trigger pulse input end on the three phase lines of each rectifier bridge on the multiple rectifier bridges connected in parallel, and an adjustable delay module is used to delay and phase shift the pulse signal as the positive phase input of the comparator output module. An adjustable voltage module and a power supply module provide an adjustable voltage output as the negative phase input of the comparator output module, so as to flexibly change the output signal of the comparator output module, thereby making the trigger angle of the thyristor on the three phase lines of the rectifier bridge change to a certain degree to meet different current equalization requirements.

[0074] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A device for realizing parallel operation of multiple rectifier bridge cabinets and current equalization output, characterized in that: It includes a pulse phase shifting device and a plurality of rectifier bridges connected in parallel; The number of the pulse phase shifting devices corresponds to the number of the rectifier bridges, and the output ends of the pulse phase shifting devices are respectively connected to the trigger pulse input ends of the thyristors on the three phase lines of the rectifier bridges; The pulse phase shifting device is used to change the trigger angle of the thyristor; The pulse phase shifting device comprises a comparator output module, an adjustable delay module, an adjustable voltage module and a power supply module; The input end of the adjustable delay module is used for external pulse signal, the output end of the adjustable delay module is connected to the positive phase input end of the comparator output module, the output end of the adjustable voltage module is connected to the negative phase input end of the comparator output module, and the output end of the comparator output module is respectively connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge; The power supply module is respectively connected to the power supply end of the adjustable delay module and the power supply end of the adjustable voltage module; The adjustable voltage module includes a fifth resistor and a variable resistor network; One end of the fifth resistor is connected to the power module, and the other end of the fifth resistor is simultaneously connected to the inverting input end of the comparator output module and the first common end of the variable resistor network; The second common terminal of the variable resistance network is grounded.

2. A device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to claim 1, characterized in that: The adjustable delay module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first switch, a first capacitor, a second capacitor and a third capacitor; One end of the first resistor is connected to the power module, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is simultaneously connected to the positive input end of the comparator output module, one end of the third resistor, one end of the first capacitor and one end of the first switch, the other end of the first switch is simultaneously connected to one end of the second capacitor, the other end of the second capacitor is connected to one end of the third capacitor, and the other ends of the three resistors are connected to one end of the fourth resistor; The other end of the second capacitor, the other end of the third capacitor and the other end of the fourth resistor are all grounded, and the connection point between the first resistor and the second resistor is used for externally connecting a pulse signal.

3. The device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to claim 2 is characterized in that: A diode is further connected between the first resistor and the second resistor; The anode of the diode is connected to an end of the first resistor away from the power module, and the cathode of the diode is connected to an end of the second resistor away from the comparator output module; The connection point between the second resistor and the cathode of the diode is used for externally connecting a pulse signal.

4. The device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to claim 1 is characterized in that: The variable resistor network includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a second switch, a third switch and a fourth switch; One end of the sixth resistor is simultaneously connected to the other end of the fifth resistor, the inverting input end of the comparator output module, one end of the second switch, one end of the third switch and one end of the fourth switch, the other end of the second switch is connected to one end of the seventh resistor, the other end of the third switch is connected to one end of the eighth resistor, and the other end of the fourth switch is connected to one end of the ninth resistor; The other end of the sixth resistor, the other end of the seventh resistor, the other end of the eighth resistor and the other end of the ninth resistor are all grounded.

5. The device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to claim 1, characterized in that: The comparator output module includes an operational comparator, a fourth capacitor, a tenth resistor and an eleventh resistor; The non-phase input terminal of the operational comparator is simultaneously connected to one end of the fourth capacitor, one end of the eleventh resistor and the output end of the adjustable delay module, the inverting input terminal of the operational comparator is simultaneously connected to one end of the tenth resistor and the output end of the adjustable voltage module, and the output end of the operational comparator is simultaneously connected to the other end of the fourth capacitor, the other end of the tenth resistor, the other end of the eleventh resistor and the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge.

6. The device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to claim 1, characterized in that: The pulse phase shifting device also includes an optical coupling isolation module; The output end of the comparator output module is respectively connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge through the optical coupling isolation module, and the power supply module is connected to the power supply end of the optical coupling isolation module.

7. The device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to claim 6, characterized in that: The optical coupling isolation module includes an optical coupler, a twelfth resistor and a thirteenth resistor; The positive input end of the optical coupler is simultaneously connected to one end of the twelfth resistor and one end of the thirteenth resistor, and the other end of the twelfth resistor is simultaneously connected to the power module and the other end of the thirteenth resistor; The negative input end of the optical coupler is connected to the output end of the comparator output module, the output end of the optical coupler is connected to the trigger pulse input end of the thyristor on the three phase lines of the rectifier bridge, and the ground end of the optical coupler is grounded.

8. The device for realizing parallel operation of multiple rectifier bridge cabinets and current-balanced output according to claim 7, characterized in that: The optical coupler is a TCET1100 optical coupler.

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