Implementation of a new remote islanding detection method for wind-solar hybrid power plants

The integration of the distributed generation (DG) systems into the power grid is a significant issue to provide a reliable operation of the power system. DG systems must meet some technical requirements to achieve a successful grid connection. Islanding is also a vital issue for a reliable integration of DG systems with the grid. There have been many islanding detection methods researched in the literature, but most of them have some boundaries related to the local load and the inverter. In this study, a new remote islanding detection method is introduced for a developed wind-solar hybrid power plant, and a practical solution is researched by classifying the current methods. The proposed method monitors and controls the grid, local load and the output of the PV inverter in real time with the communication of circuit breakers. The proposed remote control system detects the changes in the currents of the circuit breakers, frequency and the active powers by checking the defined threshold values at all electrical branches of the hybrid DG system. When the breaker current goes to zero, or they are under/over defined threshold values, the circuit breakers are tripped by using a real-time control system that is developed with Labview. The proposed method also checks the frequency, active powers, and reactive powers with the currents in real-time, so it is independent of the load, and it is not inverter resident. Islanding detection time is just a cycle, and it is a considerably short response time according to the current standards. Non-detection zone (NDZ) is also zero in the proposed method. The experimental results prove that the developed remote islanding detection method is easily implemented in wind-solar DG systems, and it is also suitable for real system applications. (C) 2015 Elsevier Ltd. All rights reserved.