Compensator for electric-railway non-power compensation and electric-energy quality control

Abstract

The invention is concerned with the compensation equipment that uses for electrification railroad reactive power compensation and the electrical energy quality control, including: two groups of passive filters using to provide reactive power for electrification railroad locomotive and filters the harmonic current of the electrification locomotive; two groups of contravariant equipments using to create current that can control the breadth value, the phase and the frequency; two groups of transformers using to coupling the current from the two contravariant equipments to the supply are of the electrification railroad; the public direct-current unit using to transform the active power between the two groups of contravariant equipments and provide the direct-current to the two groups of contravariant equipments. The invention can process power factor compensation for the electrification railroad supply system, control the quality of the electricity energy.

Description

technical field [0001] The invention relates to a compensation device for reactive power compensation and power quality control of electrified railways, in particular to a reactive power compensation for electrified railways, and control of power quality including negative sequence, harmonics, voltage fluctuations and flicker. The utility model relates to a comprehensive compensating device for governance, which belongs to the field of electrified railway power supply. Background technique [0002] For the power supply system, the electrified railway is a typical unbalanced nonlinear impact load, which has a serious adverse effect on the normal safety and economic operation of the power grid. First, the electric railway load generally adopts single-phase power supply. For the three-phase system, the load has a strong asymmetrical characteristic, which generates a very large fundamental negative sequence current (including harmonic components), and the three-phase power suppl...

AI Technical Summary

Problems solved by technology

First, the electric railway load generally adopts single-phase power supply. For the three-phase system, the load has a strong asymmetrical characteristic, which generates a very large fundamental negative sequence current (including harmonic components), and the three-phase power supply system of the power grid operates symmetrically. and rotating electrical equipment; it will also have adverse effects on the traction load of the electric railway; second, the electric locomotive is a high-power single-phase rectification load, which generates large harmonics, which seriously distorts the waveform quality of the power supply public network; Third, the electric railway load has the characteristics of high power and impact, which causes serious deviation and fluctuation of the voltage of the grid power supply system, affecting the power quality and safe operation of the grid; fourth, the power factor of the electric railway load is low, and the impact is large. Increase the offset of power supply voltage, make reactive power compensation difficult, and make the operation less economical

[0003] The traditional traction substation adopts fixed capacitance compensation, the compensation capacity cannot track the load change, and the situation of reactive power feedback often occurs, and the operation economy is poor; moreover, due to the existence of current harmonics and negative sequence components, the safety of capacitor operation in the traction substation is limited. If it is not guaranteed, not only the operation loss will be very large, but also the normal operation of the electric railway equipment will be affected

[0004] The use of balance transformers or other transformers with special structures can improve the imbalance of the power supply system to a certain extent, but other devices must be used to improve the power factor or suppress harmonics, and the price of such special transformers is relatively expensive

[0005] The use of thyristor controlled reactor (hereinafter referred to as TCR) type static var compensator (hereinafter referred to as SVC) can effectively improve the imbalance of the power supply system and reduce the negative sequence current, but the TCR itself will produce a large number of harmonics during operation. , a large-capacity filter must be used to remove the harmonics of the electric iron itself and the harmonics generated by the TCR, and the equipment occupies a large area; since the SVC can only output reactive current, a large capacity is required to compensate the negative sequence in the traction grid and reactive current, the overall equipment investment is huge; in addition, the reactor loss in the TCR is very severe, and the operation and maintenance costs are extremely high

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