Voltage detection-type active filter for improving electric energy quality of PCC position

Abstract

The invention provides a voltage detection-type active filter for improving electric energy quality of a PCC position. The voltage detection-type active filter comprises a power electronic converter,an LCL filtering circuit, a DC-side capacitor, a network-side current detection interface circuit, a DC-side voltage detection interface circuit, a PPC voltage and zero-crossing detection circuit anda processor, wherein the processor is connected with the power electronic converter, the network-side current detection interface circuit, the DC-side voltage detection interface circuit and the PPC voltage and zero-crossing detection circuit, the power electronic converter is connected with the LCL filtering circuit and the DC-side capacitor, the LCL filtering circuit is connected with the network-side current detection interface circuit, and the DC-side capacitor is connected with the DC-side voltage detection interface circuit. By the voltage detection-type active filter, a PCC harmonic voltage is only extracted, a current is not extracted, the hardware structure is simplified, the influence speed is increased, the designated subharmonic voltage can be eliminated, the voltage detection-type active filter is simple to control and simple and convenient to operate, the method is reasonable, and power grid compensation can be performed in real time.

Description

technical field [0001] The invention relates to the filtering technical field of power systems, in particular to a voltage detection active filter for improving power quality at a PCC. Background technique [0002] The power quality problem has always been one of the hot spots in the power system. With the surge of nonlinear loads in the power system, the problem of harmonic current and voltage distortion becomes more prominent. As one of the effective methods to solve harmonic problems, active power filter is widely used in power system. From the way of accessing the power grid, it is divided into two types: series type and parallel type. At present, the parallel type is widely used. The traditional shunt active filter detects the harmonic current of the load, and the compensation device generates a compensation current equal to the harmonic current and opposite in polarity, so that the load current only contains the fundamental component. [0003] However, with the agg...

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Problems solved by technology

[0003] However, with the aggravation of load power electronics, the nonlinear loads in the distribution network have many and scattered characteristics. Obviously, the active power filter based on the current detection method has been exhausted in terms of compensation effect and economy. Not applicable, and it is difficult to quickly and correctly extract harmonic voltage when the grid voltage, frequency, and phase fluctuate, and the control method is complicated

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