A learning backstepping controller for voltage source inverter with nonlinear loads

An inverter with an output LC filter can be used for generation of sinusoidal output voltage with low harmonic distortion, suitable for distributed generation systems. However, with the growing number of electronic devices with rectifiers at the front end of their power supply, the nonlinearities of the load current in power systems are increasing. As such designing an inverter system with a nonlinear controller that can take into account this nonlinearity in the load current and generate a high quality sinusoidal output voltage has become of great interest to the academic and industrial communities. In this paper, a nonlinear backstepping controller combined with a periodic disturbance learning observer is proposed for the control of a single-phase H-Bridge inverter with an output LC filter. A Lyapunov stability analysis is utilized to demonstrate system stability. Simulation results validate the performance of the control scheme in the presence of nonlinear loads in terms of tracking objective and system stability.