Voltage Oriented Control of a Single-Phase LVDC Distribution Network Inverter

Capacitor voltage oriented PI control is implemented to control the phase voltage of a customer-end single-phase inverter in a low-voltage DC (LVDC) distribution system. Synchronous dq-frame is used to control the phase voltage to avoid the drawbacks of the PI control, such as possible steady-state error. In the paper the controller equations are derived from the system equations and then the controllers are simplified and their performances are studied. In addition to using different controller structures also different synchronization methods are considered. Finally, the measurements are made with two different control system structures, namely, PI control and PI control with capacitor voltage error feedforward, to verify the simulation results. The study reveals that the synchronous frame control is a suitable control method to control the phase voltage of the LVDC customer-end inverter. It also shows that the controller structures can be simplified drastically if the load is resistive.