Analysis of Resonance and Filtering Effect Based on the Dynamics Modeling of TAPF

A TAPF device consisting of Active Power Filter and Thyristor Switched Filter is presented in this paper to balance filtering effect, device capacity and economic benefit. Firstly, the dynamic model of the TAPF system is established under the condition of harmonic current according to the Norton´s theorem, and the resonance between the TAPF and the power grid is analyzed. Then the expressions of the harmonic currents flowing into the power grid and TAPF are given by impedance distribution theorem. The analysis results show that there is no resonance between the TAPF and the power grid and the TAPF device can suppress the harmonic current effectively in the system.