Dual-module three-phase four-bridge-arm auxiliary converter control system for metro vehicle

Abstract

The utility model discloses a dual-module three-phase four-bridge-arm auxiliary converter control system for a metro vehicle. The dual-module three-phase four-bridge-arm auxiliary converter control system comprises an auxiliary converter power circuit and an auxiliary converter control circuit for controlling the auxiliary converter power circuit, the auxiliary converter power circuit comprises a Buck three-level converter, a resonant single-phase inverter, an intermediate frequency transformer, a single-phase full-bridge rectifier, a three-phase four-bridge-arm inverter, an LC filter and a contactor. The auxiliary converter control circuit comprises a voltage-frequency composite control unit, a voltage closed-loop control unit, a current closed-loop control unit, a three-dimensional space vector control unit, a resonance inversion control unit, a Buck three-level control unit, a synchronous phase locking unit, a phase angle selection unit, an instantaneous power calculation unit and a droop control unit. The utility model provides a dual-module three-phase four-bridge-arm auxiliary converter control system for a metro vehicle, which reduces the loss of a power circuit switch in the system, improves the conversion efficiency of the system and greatly prolongs the service life of equipment.

Description

Technical Field

[0001] The utility model relates to a dual-module three-phase four-bridge-arm auxiliary converter control system for a subway vehicle, belonging to the field of auxiliary power supply for rail transit vehicles. Background Art

[0002] Auxiliary converters are essential electrical components on subway vehicles, mainly used to supply power to vehicle ventilators, air conditioning equipment, air compressors and other three-phase loads and lighting and control system equipment.

[0003] At present, most subway vehicles at home and abroad use mature static auxiliary converters. Most traditional auxiliary converters use direct power from the contact network for inversion, and the main power circuit part only has three-phase inverters and power frequency transformers. Its advantages are: simple hardware topology and simple control system; its disadvantages are: large box size, heavy weight, low efficiency, and large switching loss. In order to meet the requirements of standard subway vehicle uniformity, it is imperative to develop and design a dual-module three-phase four-bridge-arm auxiliary converter control system. Summary of the invention

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a dual-module three-phase four-bridge-arm auxiliary converter control system for subway vehicles, thereby reducing the loss of power circuit switches in the system, improving the conversion efficiency of the system, and greatly extending the service life of the equipment.

[0005] In order to solve the above technical problems, the technical solution of the utility model is:

[0006] A dual-module three-phase four-bridge-arm auxiliary converter control system for a subway vehicle, comprising an auxiliary converter power circuit and an auxiliary converter control circuit;

[0007] The auxiliary converter power circuit includes a Buck three-level converter, a resonant single-phase inverter, an intermediate frequency transformer, a single-phase full-bridge rectifier, a three-phase four-bridge-arm inverter, an LC filter and a contactor, wherein the input end of the Buck three-level converter is connected to the contact network DC bus, the output end of the Buck three-level converter is connected to the input end of the resonant single-phase inverter, the output end of the resonant single-phase inverter is connected to the input end of the intermediate frequency transformer, the output end of the intermediate frequency transformer is connected to the input end of the single-phase full-bridge rectifier, the output end of the single-phase full-bridge rectifier is connected to the input end of the three-phase four-bridge-arm inverter, the output end of the three-phase four-bridge-arm inverter is connected to one end of the LC filter, the other end of the LC filter is connected to one end of the contactor, and the other end of the contactor is connected to the three-phase AC bus;

[0008] The auxiliary converter control circuit includes a voltage-frequency composite control unit, a voltage closed-loop control unit, a current closed-loop control unit, a three-dimensional space vector control unit, a resonant inverter control unit, a Buck three-level control unit, a synchronous phase-locking unit, a phase angle selection unit, an instantaneous power calculation unit and a droop control unit;

[0009] The input end of the Buck three-level control unit is connected to the output end of the Buck three-level converter, and is used to collect the Buck output voltage and output current; the output end of the Buck three-level control unit is used to control the on and off of the power switch device of the Buck three-level converter;

[0010] The input end of the resonant inverter control unit is connected to the output end of the resonant inverter, and is used to collect the output voltage of the resonant inverter; the output end of the resonant inverter control unit is used to control the on and off of the power switch device of the resonant inverter;

[0011] The input end of the voltage-frequency composite control unit is connected to one end of the contactor, and is used to sample the phase voltage value of the three-phase AC; the phase angle output end of the voltage-frequency composite control unit is connected to the input end of the phase angle selection unit;

[0012] The input end of the synchronous phase-locking unit is connected to the other end of the contactor, and is used to sample the phase voltage value of the three-phase AC bus; the voltage output end of the synchronous phase-locking unit is connected to the input end of the droop control unit and is fed back, and the phase angle output end of the synchronous phase-locking unit is connected to the input end of the phase angle selection unit;

[0013] The input end of the instantaneous power calculation unit is connected to the other end of the LC filter, and is used to sample the phase voltage value and the phase current value of the three-phase AC; the output end of the instantaneous power calculation unit is connected to the input end of the droop control unit, and the voltage setting output end of the droop control unit is connected to the first input end of the voltage closed-loop control unit;

[0014] The second input end of the voltage closed-loop control unit is connected to one end of the contactor for sampling the phase voltage value of the three-phase AC; the phase angle input end of the voltage closed-loop control unit is connected to the output end of the phase angle selection unit, and the output end of the voltage closed-loop control unit is connected to the first input end of the current closed-loop control unit;

[0015] The second input end of the current closed-loop control unit is connected to one end of the contactor for sampling the phase current value of the three-phase AC, and the output end of the current closed-loop control unit is connected to the input end of the three-dimensional space vector control unit;

[0016] The output end of the three-dimensional space vector control unit is used to control the opening and closing of the power devices of the three-phase four-bridge arm inverter unit.

[0017] Furthermore, the LC filter is a three-phase LC filter.

[0018] Furthermore, the auxiliary converter power circuit is provided with two paths, and the two auxiliary converter power circuits are connected in parallel.

[0019] Furthermore, the auxiliary converter control circuit is provided with two paths, and each path of the auxiliary converter control circuit controls one path of the auxiliary converter power circuit.

[0020] By adopting the above technical scheme, the utility model realizes the common bus output of a single dual-module three-phase four-bridge arm auxiliary converter, and uses three-dimensional space vector control of positive-sequence, negative-sequence and zero-sequence voltage and current double closed loops, and the control reliability is significantly improved. It can realize both stable voltage output and common bus output of output phase voltage, and the harmonic content of AC output voltage and current is low and within the standard range. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a principle block diagram of a dual-module three-phase four-bridge-arm auxiliary converter power supply system for subway vehicles of the utility model;

[0022] Figure 2 It is a control schematic diagram of the auxiliary converter control circuit and the auxiliary converter power circuit of the utility model. DETAILED DESCRIPTION

[0023] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0024] like Figure 1 As shown, this embodiment provides a dual-module three-phase four-bridge-arm auxiliary converter control system for subway vehicles, which includes two auxiliary converter power circuits connected in parallel, and each auxiliary converter power circuit is controlled by an auxiliary converter control circuit.

[0025] like Figure 2 As shown, the auxiliary converter power circuit of this embodiment includes a Buck three-level converter, a resonant single-phase inverter, a medium-frequency transformer, a single-phase full-bridge rectifier, a three-phase four-leg inverter, a three-phase LC filter and a contactor.

[0026] The input end of the Buck three-level converter is connected to the overhead line DC bus, the output end of the Buck three-level converter is connected to the input end of the resonant single-phase inverter, the output end of the resonant single-phase inverter is connected to the input end of the medium-frequency transformer, the output end of the medium-frequency transformer is connected to the input end of the single-phase full-bridge rectifier, the output end of the single-phase full-bridge rectifier is connected to the input end of the three-phase four-bridge-arm inverter, the output end of the three-phase four-bridge-arm inverter is connected to one end of the three-phase LC filter, the other end of the three-phase LC filter is connected to one end of the contactor, and the other end of the contactor is connected to the three-phase AC bus. The power supply voltage of the urban rail train is the rated voltage of the overhead line of 1500V, which is first stepped down and stably controlled at 640V after passing through the Buck three-level converter, the resonant single-phase inverter, the medium-frequency transformer and the single-phase full-bridge rectifier, and then inverted by the three-phase four-bridge-arm inverter to output 220V phase voltage and 380V line voltage. Therefore, a contactor is added to the output end of each three-phase four-leg inverter, and the contactor can be attracted when the phase and amplitude are within the control error range.

[0027] like Figure 2 As shown, the auxiliary converter control circuit of this embodiment includes a voltage-frequency composite control unit, a voltage closed-loop control unit, a current closed-loop control unit, a three-dimensional space vector control unit, a resonant inverter control unit, a Buck three-level control unit, a synchronous phase-locked unit, a phase angle selection unit, an instantaneous power calculation unit and a droop control unit.

[0028] The input end of the Buck three-level control unit is connected to the output end of the Buck three-level converter for collecting the Buck output voltage and output current; the output end of the Buck three-level control unit is used to control the on and off of the power switch device of the Buck three-level converter.

[0029] The input end of the resonant inverter control unit is connected to the output end of the resonant inverter for collecting the output voltage of the resonant inverter; the output end of the resonant inverter control unit is used to control the on and off of the power switch device of the resonant inverter to realize soft switching technology.

[0030] The input end of the voltage-frequency composite control unit is connected to one end of the contactor for sampling the phase voltage value of the three-phase AC; the phase angle output end of the voltage-frequency composite control unit is connected to the input end of the phase angle selection unit.

[0031] The input end of the synchronous phase-locking unit is connected to the other end of the contactor for sampling the phase voltage value of the three-phase AC bus; the voltage output end of the synchronous phase-locking unit is connected to the input end of the droop control unit and is fed back, and the phase angle output end of the synchronous phase-locking unit is connected to the input end of the phase angle selection unit.

[0032] The input end of the instantaneous power calculation unit is connected to the other end of the three-phase LC filter for sampling the phase voltage and phase current values ​​of the three-phase AC; the output end of the instantaneous power calculation unit is connected to the input end of the droop control unit, and the voltage setting output end of the droop control unit is connected to the first input end of the voltage closed-loop control unit.

[0033] The second input end of the voltage closed-loop control unit is connected to one end of the contactor for sampling the phase voltage value of the three-phase AC; the phase angle input end of the voltage closed-loop control unit is connected to the output end of the phase angle selection unit, and the output end of the voltage closed-loop control unit is connected to the first input end of the current closed-loop control unit, and is output to the current closed-loop control unit after positive-sequence, negative-sequence, and zero-sequence vector decoupling transformation closed-loop control.

[0034] The second input end of the current closed-loop control unit is connected to one end of the contactor for sampling the phase current value of the three-phase AC. The output end of the current closed-loop control unit is connected to the input end of the three-dimensional space vector control unit, and is output to the three-dimensional space vector control unit after positive-sequence, negative-sequence, and zero-sequence vector decoupling transformation closed-loop control.

[0035] After being modulated by the three-dimensional space vector control unit, it is output to the three-phase four-bridge-arm inverter unit of the power circuit. The output end of the three-dimensional space vector control unit is used to control the opening and closing of the power devices of the three-phase four-bridge-arm inverter unit.

[0036] like Figure 2 As shown, the working principle of the dual-module three-phase four-bridge-arm auxiliary converter control system for subway vehicles in this embodiment is as follows:

[0037] When the system is working, the Buck three-level control unit collects the output voltage U1, and through the voltage closed-loop control, the Buck voltage is stabilized to the given value output. The resonant inverter control unit collects the output voltage U2, and through the voltage closed-loop control, the resonant single-phase inverter implements soft switching technology. The synchronous phase-locked unit collects the three-phase AC bus voltage U un1 , U vn1 , U wn1 , using U un1 , U vn1 , U wn1 and the reference frequency f * , the phase angle adjustment value Theta2 and the droop voltage adjustment value U0 are calculated, and the phase angle adjustment value feedback will synchronize the phase-locked unit and the voltage and current closed-loop control unit.

[0038] The instantaneous power calculation unit collects the output voltage of the three-phase LC filter and the current I of the three-phase circuit. un ,I vn and I wn , using the three-phase AC current I un ,Ivn and I wn And the three-phase AC voltage U un , U vn , U wn Calculate the active power P and reactive power Q of the three-phase four-leg inverter. The droop control unit combines P and Q to calculate the voltage regulation value U * .

[0039] The voltage-frequency composite control unit collects the three-phase AC voltage U un , U vn , U wn , the phase angle adjustment value Theta1 is calculated. The phase angle adjustment values ​​Theta1 and Theta2 enter the phase angle selection unit according to the master-slave command. If it is a master, the phase angle Theta1 is selected, and if it is a slave, the phase angle Theta2 is selected.

[0040] The input value of the voltage closed-loop control unit is the voltage regulation value U * , collect three-phase AC voltage U un , U vn , U wn After the positive, negative and zero sequence vector decoupling transformation and the respective closed loop regulation calculation, the positive, negative and zero sequence current closed loop regulation given values ​​of the current closed loop control unit are obtained. The current closed loop control unit collects the three-phase AC current I un ,I vn ,I wn After positive, negative and zero-sequence vector decoupling transformation and respective closed-loop regulation calculation, the signals are output to the three-dimensional space vector control unit. After regulation, the three-dimensional space vector control unit outputs a PWM signal to control the on and off of the power devices of the three-phase four-leg inverter, thereby ensuring the stable operation of the dual-module auxiliary converter.

[0041] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-module three-phase four-bridge-arm auxiliary converter control system for subway vehicles, characterized in that: It includes an auxiliary converter power circuit and an auxiliary converter control circuit for controlling the auxiliary converter power circuit; The auxiliary converter power circuit includes a Buck three-level converter, a resonant single-phase inverter, an intermediate frequency transformer, a single-phase full-bridge rectifier, a three-phase four-bridge-arm inverter, an LC filter and a contactor, wherein the input end of the Buck three-level converter is connected to the contact network DC bus, the output end of the Buck three-level converter is connected to the input end of the resonant single-phase inverter, the output end of the resonant single-phase inverter is connected to the input end of the intermediate frequency transformer, the output end of the intermediate frequency transformer is connected to the input end of the single-phase full-bridge rectifier, the output end of the single-phase full-bridge rectifier is connected to the input end of the three-phase four-bridge-arm inverter, the output end of the three-phase four-bridge-arm inverter is connected to one end of the LC filter, the other end of the LC filter is connected to one end of the contactor, and the other end of the contactor is connected to the three-phase AC bus; The auxiliary converter control circuit includes a voltage-frequency composite control unit, a voltage closed-loop control unit, a current closed-loop control unit, a three-dimensional space vector control unit, a resonant inverter control unit, a Buck three-level control unit, a synchronous phase-locking unit, a phase angle selection unit, an instantaneous power calculation unit and a droop control unit; The input end of the Buck three-level control unit is connected to the output end of the Buck three-level converter, and is used to collect the Buck output voltage and output current; the output end of the Buck three-level control unit is used to control the on and off of the power switch device of the Buck three-level converter; The input end of the resonant inverter control unit is connected to the output end of the resonant inverter, and is used to collect the output voltage of the resonant inverter; the output end of the resonant inverter control unit is used to control the on and off of the power switch device of the resonant inverter; The input end of the voltage-frequency composite control unit is connected to one end of the contactor, and is used to sample the phase voltage value of the three-phase AC; the phase angle output end of the voltage-frequency composite control unit is connected to the input end of the phase angle selection unit; The input end of the synchronous phase-locking unit is connected to the other end of the contactor and is used to sample the phase voltage value of the three-phase AC bus; The voltage output end of the synchronous phase-locking unit is connected to the input end of the droop control unit and is fed back, and the phase angle output end of the synchronous phase-locking unit is connected to the input end of the phase angle selection unit; The input end of the instantaneous power calculation unit is connected to the other end of the LC filter, and is used to sample the phase voltage value and the phase current value of the three-phase AC; the output end of the instantaneous power calculation unit is connected to the input end of the droop control unit, and the voltage setting output end of the droop control unit is connected to the first input end of the voltage closed-loop control unit; The second input end of the voltage closed-loop control unit is connected to one end of the contactor for sampling the phase voltage value of the three-phase AC; the phase angle input end of the voltage closed-loop control unit is connected to the output end of the phase angle selection unit, and the output end of the voltage closed-loop control unit is connected to the first input end of the current closed-loop control unit; The second input end of the current closed-loop control unit is connected to one end of the contactor for sampling the phase current value of the three-phase AC, and the output end of the current closed-loop control unit is connected to the input end of the three-dimensional space vector control unit; The output end of the three-dimensional space vector control unit is used to control the opening and closing of the power devices of the three-phase four-bridge arm inverter unit.

2. The dual-module three-phase four-bridge-arm auxiliary converter control system for subway vehicles according to claim 1 is characterized in that: The LC filter is a three-phase LC filter.

3. The dual-module three-phase four-bridge-arm auxiliary converter control system for subway vehicles according to claim 1, characterized in that: The auxiliary converter power circuit is provided with two paths, and the two paths of the auxiliary converter power circuit are connected in parallel.

4. The dual-module three-phase four-bridge-arm auxiliary converter control system for subway vehicles according to claim 3 is characterized in that: The auxiliary converter control circuit is provided with two paths, and each path of the auxiliary converter control circuit controls one path of the auxiliary converter power circuit.

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