Traction power supply direct hanging type high voltage comprehensive compensation device

Abstract

The invention discloses a traction power supply direct hanging type high voltage comprehensive compensation device, which belongs to the field of electric energy quality control. The traction power supply direct hanging type high voltage comprehensive compensation device comprise 2 K-level cascade arms, 2k energy storage capacitors, and K isolated type both-way DC converts (2). A rectification side voltage converter (3) is connected with an inversion side voltage converter (4) through a high frequency isolating transformer (5). K DC leading-out terminals of the rectification side voltage converter (3) are connected in parallel with power units corresponding to left K-level cascade arms (1-1) through the energy storage capacitors; The K DC leading-out terminals of the inversion side voltage converter (4) are connected in parallel with power units corresponding to right K-level cascade arms (1-2) through the energy storage capacitors; and the level number K is a positive integer from 1 to 100. The traction power supply direct hanging type high voltage comprehensive compensation device can directly access a traction network without an input-output line frequency transformer through an AC reactor, and can realize the comprehensive compensation including negative sequence, idle work, and harmonic wave.

Description

technical field [0001] The invention relates to a device for improving power quality, in particular to a high-voltage comprehensive compensation device for traction power supply that is directly connected to a grid without the coupling of a power frequency transformer. Background technique [0002] As a large-capacity single-phase nonlinear load, when an electric locomotive is connected to a three-phase symmetrical power system through a traction transformer, a large amount of negative sequence current, harmonic current and reactive component are usually injected into it, which affects the power quality of the power supply system. China's traction power supply system is a different-phase power supply mode. The commonly used phase sequence rotation technology and the use of balancing transformer technology can only improve the influence of negative sequence current within a certain range. Due to the randomness of traction loads in space and time distribution, they The effects...

AI Technical Summary

Problems solved by technology

China's traction power supply system is a different-phase power supply mode. The commonly used phase sequence rotation technology and the use of balancing transformer technology can only improve the influence of negative sequence current within a certain range. Due to the randomness of traction loads in space and time distribution, they The effects that can be produced are limited, and sometimes have a negative impact on the performance of the system

In addition, the inherent electrical phase separation link of the out-of-phase power supply mode is its weak link, and has a great constraint effect on high-speed and heavy-load operation

The use of the same-phase power supply mode can avoid or reduce the phase separation link of the traction network, and then solve a series of problems caused by the electric phase separation, and greatly improve the transport capacity of the train. However, the disadvantage of the same-phase power supply scheme is that it is easy to cause negative sequence current, resulting in The imbalance problem is more serious

Active power filters and reactive power compensation circuits (Reactive Power Compensation, RPC) are effective solutions to improve power quality. However, in high-voltage applications, due to the limitations of device withstand voltage and capacity levels, commonly used The method is to connect to the high-voltage power grid through a power frequency transformer. The bulky power frequency transformer greatly increases the cost and volume of the power electronic conversion device, and limits the efficiency of the system. It is difficult to popularize and apply it in the traction power supply system.

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