Lagrange Modeling and a Novel Passivity-Based Control of a Single-phase inverter Applied in Neutral-Line Active Power Filter

In this paper, we apply passivity-based control theory in a single-phase pulse-width modulation (PWM) voltage-source inverter using Euler-Lagrange(EL) dynamics equation. The EL model derived from the Lagrange function and EL equation indicates the accordance with the time-domain model of state equation. If proper damping was injected into the system through the controller designed, Energy-dissipative properties of the model could be fully retained, i.e., the energy storage function H(x) and its differential H dot , which denotes the change rate of H(x), meet the request of the Passivity theory. Based on the EL model, passivity-based controllers are then synthesized using the techniques of energy shaping and damping injection, which have the features of enhanced robustness, guaranteed zero steady-state error, faster response and good stability at moment of load disturbance. Furthermore, we introduce a method of a single-phase inverter applied in the neutral-line active power filter system through a novel topology. Finally, simulation results on a 10 kVA neutral-line active power filter provide verification of the salient features above.