A multi-resolution control strategy for DSP controlled 400Hz shunt active power filter in an aircraft power system

A multi-resolution control strategy is proposed for a DSP-controlled 400 Hz Active Power Filter(APF) to reduce the real-time computational requirements. In this manner, the current loop bandwidth is extended for better harmonic compensating performance. By rearranging the computational elements into high and low computational groups, the proposed control strategy takes best advantages of the DSP computation resources to increase the control frequency for the high computational group. Based on the control bandwidth, analysis is presented in determining the sampling frequency for the low computational group. A 20 kVA prototype is setup to verify the validity of the proposed strategy. Experimental results show that the proposed control strategy achieves good current compensating effects and dynamic performance.