Output Power Regulation of a Virtual Oscillator Controlled Inverter

An output power regulation strategy is presented for a virtual oscillator controlled inverter. With multiple inverters feeding a microgrid, an output power regulation technique is imperative to utilize these distributed energy sources efficiently and reducing the distribution line stress and losses, and equitably sharing revenue streams. It is demonstrated that a PI controller can be used to regulate the output power by tuning the current feedback gain of the virtual oscillator controller. Adjusting the current feedback gain affects the inverter terminal voltage magnitude. In order to investigate the local stability of the system, a linearization and eigenvalues analysis is performed. Further, explicit conditions are specified to ensure the local stability of the system with varying controller and load parameters. A polynomial Lyapunov function is determined using the sum of squares technique to investigate the global stability of the system. A brief overview illustrating the effect of variations in VOC-parameters on the system performance is provided. Simulation results establish the merits of the proposed control scheme.