Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Stationary Reference Frame Voltage Controller for Single Phase Grid Connected Inverter for Stand Alone Mode
Authors Chang-Pyo Hong ; Hag-Wone Kim ; Kwan-Yuhl Cho ; Byoung-Kuk Lim
DOI 10.6113/TKPE/2015.20.6.517
Page pp.517-525
ISSN 1229-2214
Keywords Single phase PWM inverter; Stand alone mode; Controller; Nonlinear load; Feedforward
Abstract A grid connected inverter must be operated as the main electricity source under an isolated condition caused by the grid problem. Conventionally, the dual loop controller is used for the grid inverter, and the controller is used for control under the stand-alone mode. Generally, the PI(Proportional - Integral) controller is highly efficient under a synchronous reference frame, and stable control can be available. However, in this synchronous frame-based control, high-quality DSP is required because many sinusoidal calculations are necessary. When the PI control is conducted under a stationary frame, the controller constructions are made simple so that they work even with a low-price micro controller. However, given the characteristics of the PI controller, it should be designed with the phase of reference voltage considered. Otherwise, the phase delay of the output voltage can occur. Although the current controller also has a higher bandwidth than the voltage controller, distortion of the voltage is difficult to avoid only by the rapid response of the PI controller, as a sudden load change can occur in the nonlinear load. In this study, a new control method that solves the voltage controller bandwidth problem and rapidly copes with it even in the nonlinear load situation is proposed. The validity of the proposed method is proved by simulation and experimental results.