An Anti-Islanding Protection for VSM Inverters in Distributed Generation

Virtual synchronous machine (VSM) technology is an attractive control method for an inverter-based distributed generation (DG) due to having the voltage, and frequency support functionality. Embedding an anti-islanding protection (AIP) scheme with a high accuracy is a requirement for DG inverters due to the safety concern of the personnel, and hazardous operation. This paper presents a novel hybrid AIP scheme for VSM inverters for integration of DG sources into the grid. The main advantage of this AIP scheme is that the proposed scheme can be embedded into the control of the DG inverters without a need of additional part in the hardware of the inverter, and any change in the controller. A detailed modeling of its implementation with the inverter control is presented, and the performance of the AIP scheme is verified by simulations, and experiments. It is shown that the AIP scheme detects the islanding condition successfully, and isolates the inverter from the grid after it experiences an islanding condition.