A large signal stabilizer for high damping performance of PWM load converter with input LCL-filter

This paper develops a robust tool for the treatment of AC side stability problems occurring in interconnecting PWM voltage source converter with passive LCL filter. An LCL filter can reduce the harmonics introduced by PWM switching frequency and guarantee low currents THD using small component values comparing to the L filter solution. Nevertheless, the additional poles introduced by the LC part induce resonance in the system, leading to stability problems. To deal with this problem, in this contribution, a large signal stabilizing supervisor based on the indirect Lyapunov theory will be designed. The main objective of this stabilizer is to ensure both efficiency and robustness damping proprieties by the using of the Lyapunov method for the generation of power stabilizing signals. The stability phenomenon is highlighted and the effectiveness of the global stabilizer is validated by experimental results.