Novel Harmonic Free Single Phase Variable Inductor Based on Active Power Filter Strategy

This paper presents a variable inductor for single phase system which employs a new control method based on active power filter schemes. The novel variable inductor combines an active power filter circuit and a control circuit. The active power filter circuit is based on a single phase inverter with four controllable switches, a standard H-bridge inverter. The AC side of the inverter is connected to an aid harmonic elimination winding of the variable inductor. Its DC side is connected to a filter capacitor and the secondary winding of variable inductor through the control circuit based on buck circuit. The inverter switches are controlled to shape the current through the filter inductor such that the primary current is in the same shape as the input voltage, and in the same time supply the active power consumer of control circuit. The controller is based on a conceptually simple control scheme, the energy balance concept. The advantages of new variable inductor are simplicity of control circuits, low cost and good response. In theory, the harmonic current component of the variable inductor is zero. The feasibility of this theory is verified by using Matlab/Simulink simulation results