Immersion and invariance based active disturbance rejection control for LCL grid-connected inverter

Abstract

To improve the anti-disturbance ability of LCL grid-connected inverter system, a novel immersion and invariance based on active disturbance rejection control(I&I-ADRC) scheme is proposed in this paper. First, the target system with stronger anti-disturbance ability is immersed into the ADRC standard model by using the target system mapping method of immersion and invariance control. Then, the disturbance estimated by extended state observer (ESO) is compensated, and the immersion and invariance(I&I) control law is adopted to design the state error feedback（SEF）control law, thus I&I-ADRC is built, which has improved anti-disturbance ability and dynamic response performance. The stability of grid-connected inverter system is proved by Lyapunov theory. Simulation results show that the proposed strategy can effectively suppress the disturbance and has better tracking performance.

Keywords

• lcl filter
• grid-connected inverter
• active disturbance rejection control
• immersion and invariance control
• state error feedback