Distance protection based on parameter identification considering transformer characteristics

Abstract

The distance protection method with parameter identification can distinguish internal fault from external fault correctly and avoid the transient overreach effectively based on the accurate secondary signal data. However, due to the limitation of the frequency band of the electromagnetic transformer, the secondary signal distortion is caused when the transient signal is transmitted, which limits the application of the parameter identification principle. Here, a matching method of line model and transformer type for relay protection is proposed. Analysed the appropriate frequency band of line model and transformer linear transfer frequency band and the electrical signal beyond their intersection should be filtered out. The simulation results show that this method improves the accuracy of the operation. This method not only makes sense to the practical application of distance protection based on the principle of parameter identification, but also has some reference value to other engineering applications.

Keywords

• parameter estimation
• relay protection
• power system transients
• power system faults
• fault location
• power transformer protection
• transformer characteristics
• distance protection method
• internal fault
• external fault
• accurate secondary signal data
• electromagnetic transformer
• secondary signal distortion
• transient signal
• parameter identification principle
• matching method
• line model
• relay protection
• appropriate frequency band
• transformer linear transfer frequency band
• electrical signal