Stationary frame voltage harmonic controller for standalone power generation

The paper presents a new control scheme for voltage control of voltage source inverter (VSI) with LC output filter. Proposed high performance control scheme with use of stationary regulators can be used in UPS or standalone power generation where sine wave output voltage is to be maintained. The proposed controller is able to compensate voltage distortion from unbalanced and nonlinear loads, thus controlling negative and positive voltage sequence and its harmonics. For the control purpose only voltage measurement in required. Besides, the controller can be further used in distributed power generation where the parallel operation is desired. In order to improve the parallel operation and sharing any kind of distorting loads, the proposed controller allows adjusting the gain of selected harmonics required for proper harmonic sharing. The proposed scheme is fully appropriate for digital implementation of UPS systems where high quality AC output voltage is in importance. The diagram block of the proposed controller is shown together with some simulation and experimental results. Presented controller shows outstanding performance under nonlinear and unbalanced loads which uses selective harmonic compensators.