Mixed active power filter based on ip-iq detection method and hysteresis control

Abstract

The invention relates to a mixed active power filter based on an ip-iq detection method and hysteresis control. The mixed active power filter comprises an ip-iq harmonic current detection circuit, a hysteresis control circuit, a PF (passive filter) circuit, an APF (active power filter) circuit, a coupling transformer circuit and the like. The ip-iq harmonic current detection circuit detects harmonic current of instantaneous current of each phase in a three-phase circuit, the detected harmonic current is inputted into the hysteresis control circuit to generate a hysteresis control signal, the hysteresis control circuit automatically adjusts a hysteresis width to fix switching frequency, the hysteresis control signal is inputted into the APF circuit to generate compensating current for counteracting the harmonic current, and the APF circuit is serially connected with one branch of the PF circuit and then connected into the coupling transformer circuit. The harmonic current in the harmonic three-phase circuit is effectively filtered out by combining functional advantages of an APF and the PF, performance is improved, and the total cost of the filter is reduced.

Description

technical field [0001] The invention relates to the field of power quality and power harmonic control, in particular to a hybrid active filter based on ip-iq detection method and hysteresis control. Background technique [0002] Nonlinear loads and various time-varying power electronic devices are widely used in the power grid, and a large number of harmonic currents are generated during the application process, resulting in distortion of the normal current waveform and causing serious damage to the power grid. Therefore, it is extremely urgent to suppress the harmonic current and improve the operating environment of the entire power system. At present, the solution to this problem is mainly to use a passive filter PF, an active filter APF and a hybrid active filter. What passive filter PF adopts is LC passive filter. This kind of filter is simple in structure, low in cost, and only consists of inductors and capacitors, and is quite mature in technology. The disadvantage ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a hybrid active filter, which is used to solve the problem of harmonic current filtering in the power system by combining the advantages of active and passive filtering methods, and reduce the cost of harmonic current filtering. cost, while improving the speed and accuracy of harmonic current filtering

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