Control analysis of an active power filter using Lyapunov candidate

To reduce harmonic distortion in the power lines and to improve the system power quality, the applications of active power filter (APF) has attracted a lot of attentions. A Lyapunov-based current control method for APF system is proposed. The control law is derived from directly applying the Lyapunov stability theory to the integral controller, so that the closed-loop systems possess the better harmonic current elimination. The control strategy based on Lyapunov candidate is discussed in detail and it is shown that the proposed control method provides a general design framework for the model-based harmonic current elimination and reactive power compensation. The main advantage of this approach is that Lyapunov stability analysis can be used to obtain a set of proper parameters for the integral controller. The proposed controller is validated by carrying out some experiments. Computer simulations are presented to confirm the effectiveness of the proposed control strategy and the validity of the simulation technique. Experimental results are also presented to verify the theoretical and simulation studies.