Modular energy feedback type traction power set and control method

Abstract

The invention relates to a modularized energy feedback traction power supply device and a control method thereof, wherein, the device comprises a multi-winding transformer, a plurality of PWM rectifier units and a central controller, wherein, the multi-winding transformer is provided with a primary winding and a plurality of secondary windings, and all of the secondary windings have the same connecting mode; each secondary winding of the transformer is connected with a PWM rectifier unit; the direct-current outputs of all the PWM rectifier units are connected to a direct-current bus of the general power supply device in serials. Double closed-loop control of voltage and current is adopted; an outer loop of direct-current voltage is arranged on the central controller and an inner loop based on synchronous rotating frame is arranged on each PWM rectifier unit. The power supply device is remarkably characterized by easy modularization, large capacity, bipolar energy transmission, high power factor, small current harmonic wave and stable direct-current voltage.

Description

technical field [0001] The invention relates to a traction power supply device and a control method, in particular to a traction power supply device and a control method which adopt a plurality of PWM rectifiers connected in parallel and have an energy feedback function. Background technique [0002] The development of urban rail transit is conducive to alleviating the increasing congestion of urban traffic, improving the living environment of the city and promoting the sustainable development of the city. [0003] At present, the traction power supply devices of China's subways and light rails use traditional diode rectifiers, and the power supply voltage is mainly 750V or 1500V. Although this kind of diode rectifier has a simple structure and low cost, it also has some inherent disadvantages: firstly, the energy when the vehicle brakes cannot be fed back to the AC grid, which will undoubtedly cause a lot of energy waste for rail vehicles that need frequent starting / braking...

AI Technical Summary

Problems solved by technology

Although this kind of diode rectifier has a simple structure and low cost, it also has some inherent disadvantages: firstly, the energy when the vehicle brakes cannot be fed back to the AC grid, which will undoubtedly cause a lot of energy waste for rail vehicles that need frequent starting / braking ; Secondly, the output voltage fluctuates greatly. The starting and braking of the vehicle, as well as the fluctuation of the AC input voltage, will cause large fluctuations in the DC output voltage, which is not conducive to the reliable operation of the vehicle at full power.

The third is that the vehicle needs to be equipped with a bulky braking resistor, which is not conducive to the lightweight of the vehicle, and also brings about the problem of heat dissipation; in addition, it also causes relatively large harmonic pollution to the AC power grid

The use of PWM rectifiers can overcome many of the above defects of diode rectifiers, but the capacity of a single PWM rectifier is difficult to achieve several megawatts, and the large capacity of a single unit is not conducive to the flexible configuration of the power supply system capacity, and will also reduce the reliability of power supply

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