Power grid three-phase load unbalance compensation method based on active filter

Abstract

The invention discloses a power grid three-phase load unbalance compensation method based on an active filter, which belongs to the technical field and comprises the following steps of S1, conducting load compensation current detection based on a vector orientation method, S2, a parallel active filter control structure, S3, setting a compensation structure and circuit parameters of the three-phase four-wire active filter, and S4, performing simulation verification. According to the power grid three-phase load unbalance compensation method based on the active power filter, an active power filter compensation system model is built, a basic formula is deduced, element parameters are determined, a simulation model is built, five modules of the compensation system are designed, and the provided strategy not only compensates load unbalance, andthe imbalance caused by extreme conditions can be compensated; and the method can improve three-phase imbalance, can suppress negative-sequence, zero-sequence and harmonic current, and improves power factors.

Description

Technical field [0001] The present invention relates to the field of three-phase load unbalanced compensation techniques, and in particular, to the three-phase load imbalance compensation method based on the active filter. Background technique [0002] The three-phase four-wire distribution system has been widely used in the residential and construction site due to its good economic benefits. [1-2]. Using a single-phase load on the feed line in the system can cause uneven load current, load imbalance results in excessive neutral currents, transformer overheating, and increased loss, reduce system efficiency. When there is a three-phase imbalance problem, the system must be loaded compensation. Three-phase imbalance is divided into fault imbalance and normal imbalance, wherein the failure imbalance is mainly caused by an asymmetric fault (single-phase short-circuit fault), the normal imbalance is that the load random distribution is not balanced. Since the reactive compensator can...

AI Technical Summary

Problems solved by technology

They are unreasonable distribution of three-phase loads, random changes in power loads, and weak awareness of supervision and distribution transformer loads.

In the three-phase four-wire power system, the unbalanced three-phase load will not only cause the current to pass through the neutral line, increase the loss, but also damage the transformer, reduce the efficiency of the motor, etc.

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