Application of signal detection and processing on active power filter

The paper presents a fast response signal conditioning method. Signal processing circuit which meets the requirements for Active Power Filter is built. Instead of using the Phase Lock Loop which would be complex and long time-consuming, an improved harmonic current detection method with sine/cosine function is proposed. Simulation results show that, for the same inputs, the improved method has similar accuracy with the traditional one, but runs even faster. To ensure the accuracy and speed in signal processing, a fast response digital low-pass filter is designed. Testing results on the overall circuit show that each unit of the circuit is accurate and reliable, moreover, fully consistent with the design requirements.