A CLF-based nonlinear control technique for a grid-connected voltage source inverter with LCL filter used in renewable energy power conditioning systems

A novel control scheme based on the Control Lyapunov Function (CLF) is proposed in this paper for a grid-connected voltage source inverter with an LCL filter. The proposed control approach is able to significantly increase the bandwidth of the closed-loop control system and offer a very fast transient response compared to the conventional Proportional Resonant (PR) controllers. The proposed CLF-based controller guarantees the closed-loop stability and perfect disturbance rejection for the voltage source inverter with LCL-filter. The specific Lyapunov function proposed in this paper includes the integral of the errors in order to account for parameter uncertainties in the system model. The CLF-based controller is implemented on a 1kW voltage source inverter prototype to verify the performance of the proposed control scheme. The experimental results show a significant improvement in the performance of the converter with the proposed control scheme compared to the conventional PR controller.