Mixed traction power supply equipment and control method

Abstract

The invention relates to a composite type traction power supply device which can enhance the performance of the entire power supply device and reduce the cost. The traction power supply device adopts the technical proposal that the traction power supply device comprises a diode rectification set (1), and is characterized in that a PWM rectification set (5) and a central control unit are also arranged, wherein, the diode rectification set and the PWM rectification set are respectively connected at the alternating current side and the direct current side, so as to form parallel relationship; the central control unit calculates the given values of a d shaft current and a q shaft current of each PWM rectifier unit in the PWM rectification set by detecting the two-phase alternating-current voltage, the two-phase alternating-current and the direct-current output voltage of the diode rectification set, transmits the given values to each PWM rectifier unit in the PWM rectification set through a CAN network and realizes coordination control for the diode rectification set and the PWM rectification set. The invention also discloses a control method of the device.

Description

technical field [0001] The invention relates to a power supply conversion device and a control method, in particular to a hybrid traction power supply device and a control method for traction power supply of rail transit vehicles. Background technique [0002] The development of urban rail transit is not only an effective measure to alleviate urban traffic congestion, but also an inevitable requirement for improving the urban living environment and promoting sustainable urban development. [0003] At present, my country's urban rail transit power supply devices use diode rectifiers, and the power supply voltage is 750V or 1500V. This kind of diode rectifier has been used for decades. Its biggest advantage is its simple structure and reliable performance. Some shortcomings are also becoming more and more prominent: [0004] 1. The energy cannot flow in both directions; the energy when the vehicle brakes cannot be fed back to the grid, resulting in a great waste of energy; ...

AI Technical Summary

Problems solved by technology

[0004] 1. The energy cannot flow in both directions; the energy when the vehicle brakes cannot be fed back to the grid, resulting in a great waste of energy;

[0005] 2. There is no output voltage adjustment function, and the output voltage fluctuates greatly; the fluctuation of AC input voltage and the switching between different operating conditions of the vehicle will cause large fluctuations in DC voltage (500-900V), which is not conducive to the reliable operation of the vehicle at full power ;

[0006] 3. It is necessary to add a bulky brake resistor device, which is not conducive to the light weight of the vehicle

[0007] 4. Larger harmonic pollution to the AC power grid

Therefore, some people propose to simply replace the diode rectifier in the existing traction power supply system with the PWM rectifier, but the PWM rectifier is very complicated in circuit structure and control algorithm compared with the diode rectifier, the cost is greatly increased, and the reliability is reduced

In addition, in order to reduce AC harmonics, power devices are in frequent switching states. If the PWM rectifier works in a high-power state for a long time, the energy loss will be serious.

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