Analytical analysis of shunt active power filters based on voltage detection

This paper presents a transfer-function approach to analyze filtering characteristics of a shunt active power filter (SAPF) based on voltage detection. An analytical model of the representative voltage-sensing SAPF is presented first. The issue of filter stability is then addressed. Characteristic equations in terms of system parameters are provided for the determination of system stability. The gain of a reference current generator is a critical parameter of the SAPF. The impact of the gain on filter stability, harmonic compensation, and resonance damping are addressed numerically. Finally digital simulations are performed for the validation of the analytic models as well as the analytical results.