Control method for active power filter based on double-side voltage information

Abstract

The invention discloses a control method for an active power filter based on double-side voltage information. The control method comprises the following steps of: carrying out phase locking on sampled power supply voltage to obtain a sine value of a phase angle and a starting point of power frequency cyclic waves by a digital phase-locked loop; comparing the sampled APF (Active Power Filter) direct-side capacitance voltage with a set value through a subtracter, sampling and storing and averaging according to the period of power supply voltage; carrying out PI (Proportional Integral) computation on an average value of the direct current side capacitance voltage at a starting point of the power frequency cyclic waves and outputting a fundamental wave active component amplitude of a load; multiplying the fundamental wave active component amplitude of the load with the sine value of voltage phase and outputting fundamental wave active current of the load; and subtracting the fundamental wave active current of the load from total current of the load, outputting compensation current required by the load and directly controlling a converter in a hysteresis comparison mode. According to the control method disclosed by the invention, start from a transmission angle of instantaneous active and reactive energy in the system, troublesome processes of detecting the active and reactive components are avoided and the suppression of harmonic current or compensation of reactive power is realized.

Description

technical field [0001] The invention relates to a control method of an active power filter based on double-side voltage information. Background technique [0002] Active Power Filter (APF) has been widely concerned as an effective means of dynamically suppressing harmonic current and compensating reactive power. The basic principle is to detect the harmonic current in the power grid, and then inject a current with the same amplitude and opposite phase as the original harmonic current into the grid through the controllable power semiconductor device, so that the total harmonic current of the power supply is zero, thus To achieve the purpose of real-time compensation of harmonic current. [0003] The control method of APF mainly includes two parts: the detection method of harmonic current and the control algorithm of compensation current. In the current algorithm research of APF, most of the harmonic currents in the system are first calculated by the instantaneous reactive p...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the disadvantages of traditional APF control algorithm, such as large amount of computation and complicated hardware implementation, the present invention provides a control method of active power filter based on double-side voltage information. From a different perspective, by obtaining AC and DC side voltage information and performing mathematical calculations, avoiding the cumbersome process of detecting active and reactive components, directly controlling the output current, quickly and dynamically suppressing harmonic current or compensating for reactive power

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