A Family of Voltage-Mode Control Methods for Active Power Filters and Comparative Analysis

This paper discusses a systematic method to analyze and design the control of parallel active power filters (PAPF). The discussion begins with the proposal of a novel voltage-mode control scheme. With the comparison with the widely-used current-mode control, the voltage-mode control is found more general and strait-forward for those PAPFs with the voltage- source inverter as power stage. In a view of the whole system, a general expression is proposed to abstractly describe linear control methods based on detected currents. A family of new voltage-mode control schemes is derived in a systematic way. The valid control methods are comparatively analyzed, focusing on the stability and the compensation characteristics both in steady and dynamic state. Some possible misinterpretations in reported control schemes are clarified. This paper gives not only a family of control methods for PAPF, but also a systematic way for electrical engineers to analyze and design the control method, and the generalization made in the article can also be useful for other works.