A Comparison Between Voltage Changes and ROCOF Relay Method in Islanding Detection in Presence of Different Multi-Distributed Generation Technologies

In this paper, islanding detection in the presence of different technologies of Distributed Generations (DGs), with different dynamic behaviors is discussed. Three types of DGs including Synchronous generator (SG), Wind Energy Conversation System (WECS) and Photovoltaic (PV) are considered. Also, switching of the induction motor, switching of the capacitor bank and DGs connection are studied in several cases. Switching of these utilities causes voltage sag and swell in the distribution network. Determine the exact threshold value for the correct detection in different scenarios and cases is the main discussed purpose of this paper. The network configuration with linear and nonlinear loads, DGs are simulated in PSCAD/EMTDC software. Islanding state using the voltage parameter changes in different scenario is detected. The threshold value of voltage changes in a different case study of scenarios for the best detection is set. Also, the results of the simulation are compared with the logic of Rate of Change of Frequency (ROCOF) relay method. According to different scenarios performance, the results of the simulation are discussed. As a comparison of two methods, in several cases the voltage measurement has better detection than ROCOF relay logic method. But, these results depend on the situation of the generation and consumption that is discussed in scenarios.

A Comparison Between Voltage Changes and ROCOF Relay Method in Islanding Detection in Presence of Different Multi-Distributed Generation Technologies Keywords:

Distributed Generation (DG) , Isanding Detection , Rate of Change of Frequency (ROCOF) , Voltage Changes