Three-phase active filter and non-quantized hysteresis control method for railway power distribution system

Abstract

The invention discloses a three-phase active filter used in a railway power distribution system and a non-quantized hysteresis control method. The three-phase active filter includes a hysteresis control module, and the hysteresis control module is used to implement the following steps: obtain a given reference compensation current value and a load feedback current value, use the difference between the two as an error current, and Within a working cycle, the error current is discretely sampled to obtain a discrete sequence of digital points, and multiple adjacent digital points are regarded as a group to calculate the average value of the error current of each group of digital points, and according to each group of digital points The average value of the error current controls the hysteresis loop width adjustment amount and switching frequency corresponding to the time of the next group of adjacent digital points. On the one hand, the invention can improve the accuracy of current tracking compensation, and on the other hand, can also ensure the safety of the filter circuit.

Description

technical field [0001] The invention belongs to the technical field of track power supply, and more specifically relates to a three-phase active filter and a non-quantized hysteresis control method for a railway power distribution system. Background technique [0002] With the rapid development of the domestic economy, the pressure on urban traffic operations is gradually increasing. Large and medium-sized cities in China have successively opened railways to ease the pressure on traffic operations. Railways have become an inevitable trend in future urban traffic. The power distribution system of each station is particularly important, including Scheduling, lighting, warning, elevators, turnstiles, etc. Due to the use of many modern precision power equipment, certain harmonics and reactive power will inevitably be injected into the power grid, which will seriously affect the power quality of the low-voltage distribution network, resulting in distortion of the voltage and curr...

AI Technical Summary

Problems solved by technology

However, in practical applications, the change of the error current is irregular, and it is easily affected by the sudden change of current and voltage, which makes the compensation current difficult to predict, and difficult to quantify and accurately calculate.

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