Passivity-based control method of mid-point capacitor three-phase four-wire system SAPF (shunt active power filter)

Abstract

The invention discloses a passivity-based control method of a mid-point capacitor three-phase four-wire system SAPF (shunt active power filter). The method comprises steps as follows: acquiring a mathematical model of an SAPF output side in a three-phase static uvw coordinate system; obtaining a voltage component and an inductive current component at the common ground point of the SAPF output sidein a dq0 coordinate system; obtaining a harmonic current component of three-phase load current in the dq0 coordinate system; obtaining direct current side master control current and differential pressure control current; acquiring a component of reference current in the dq0 coordinate system; obtaining a switch function of an SAPF output side switch function in the dq0 coordinate system; and obtaining a switch function of the three-phase SAPF. The method has the benefits as follows: control under the power grid balance / imbalance condition can be realized without processing of positive and negative sequence components of harmonic; adjustable parameters can be reduced, the passive controller structure is simplified, the response speed is higher, the harmonic content of power current can befurther reduced, and the method has higher robustness.

Description

technical field [0001] The invention relates to the technical field of power grids, in particular to a passive control method for a capacitive midpoint three-phase four-wire parallel active filter. Background technique [0002] In recent years, with the development of power electronics technology, semiconductor nonlinear loads in power systems are increasing, and the introduction of these loads will generate a large number of harmonics and reactive power. Although the traditional passive filter is simple in structure and convenient in operation and maintenance, it can only eliminate specific harmonics, and it is easy to generate resonance with the power grid. Shunt Active PowerFilter (SAPF), as a new type of power electronic device with ideal performance, dynamically suppresses harmonics and compensates reactive power, has better compensation effect and economical efficiency compared with traditional passive filters. benefit and has been widely used. [0003] The developme...

AI Technical Summary

Problems solved by technology

[0003] The development of the three-phase three-wire system SAPF is relatively mature, but it ignores the processing of the zero-sequence component. When the load is unbalanced, the current cannot be fed back through the zero-sequence

However, the application of passive control based on the PCHD model to the capacitive mid-point three-phase four-wire SAPF is still in its infancy.

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