M.R. Vatani - Electrical Engineering Department Amirkabir University of Technology Tehran, Iran
M.J. Sanjari - Electrical Engineering Department Amirkabir University of Technology Tehran, Iran
G. Gharehpetian - Electrical Engineering Department Amirkabir University of Technology Tehran, Iran
J.S. Moghani - Electrical Engineering Department Amirkabir University of Technology Tehran, Iran

This paper presents a new fast and reliable method for islanding detection based on measuring the utility current signal processed by discrete wavelet transform. This signal is measured before the main circuit breaker and its feature extracted by discrete wavelet transform. This feature is wavelet coefficientenergy and distinguishes the islanding conditions from nonislanding ones. Because of changing in measuring point of current signal from point of common coupling in traditional methods to before the main circuit breaker in proposed method, and using its transient data, this new method detects theislanding conditions faster than the other methods. The proposed method is useful for islanding detection in the networks with multiple distributed generations. To confirm the accuracy of this method, the method has been validated through several scenarios. Simulation results supported the robustness of the proposed method for the application considered

Islanding detection; Discrete wavelet transform; Transient signal; Feature extraction; Utility circuit breaker