A Novel Islanding Detection Scheme for Synchronous Distributed Generation Using Rate of Change of Exciter Voltage over Reactive Power at DG-Side

Penetration of distributed generation (DG) in distribution networks is rapidly increasing. DGs' application enhances system's reliability and power quality. However, along their benefits, there are some issues. One of the most important issues of DGs' application is the islanding. This paper presents a novel passive islanding detection scheme for synchronous DG based. In the proposed scheme, rate of change of exciter voltage over rate of change of reactive power at the DG-side (dE/dQDG) is taken into account. In reality, the voltage and reactive power of load depend on the exciter of the synchronous generator. Therefore, due to lack of inertia, response of these parameters to small changes is faster than the other passive parameters such as frequency. However, the sensitivity of reactive power at the DGside and the exciter voltage is much more than reactive power and voltage of the load. So, the reactive power at DG-side and exciter voltage parameters are selected. The performance of the proposed method is investigated in MATLAB/Simulink software on a sample network in the presence of synchronous dieselgenerator. The simulation results indicate that the proposed method is capable to detect all islanding and non-islanding conditions even with zero non-detection zones (NDZs) of active and reactive power mismatch.