A Lyapunov-Function Based Controller for 3-Phase Shunt Active Power Filter and Performance Assessment Considering Different System Scenarios

 Abstract

The Shunt Active Power Filter (SAPF) is a custom power device that compensates for harmonics, reactive power, and distribution power network imbalances caused by customer-side nonlinear loads in current control mode (CCM). SAPF performance as a harmonic compensator depends on the control technique used for accurate detection of the harmonic current components requiring compensation. This study proposes a 3-phase SAPF based on a Lyapunov function control approach to compensate for harmonics resulting from customer-side nonlinearity in feeder currents. The proposed strategy utilizes a control law that ensures the Lyapunov function's derivative remains consistently negative across a range of stable states. The proportional-integral (PI) controller regulates the DC-link capacitor voltage at a constant reference. This Lyapunov function-based SAPF significantly reduces the rating required compared to two conventional methods. The harmonic compensation efficacy of the proposed SAPF is compared to two conventional approaches in four system scenarios, including increasing the harmonic-constrained penetration level of renewable energy. MATLAB/Simulink simulations show that the Lyapunov function-based controller's performance improves total harmonic distortion (THD) of source current, dynamic and steady-state performance compared to the other two conventional methods. Additionally, the SAPF demonstrates robust compensation performance when dealing with high penetration of renewable energy.

Keywords

SAPF, Lyapunov function, Harmonic compensation, Hysteresis controller, Renewable energy