With regards to FCL terminal fault and short-line fault in power transmission lines installed with inductive FCL, mathematical formula are presented, based on theoretical analysis and deduction, to properly describe the relationship .

With regards to FCL terminal fault and short-line fault in power transmission lines installed with serial-resonant FCL,the influence of current limiting inductance and its parallel stray capacitance on interrupting fault current,the first peak valve of transient recovery voltage and rate of rise of transient recovery voltage of circuit breakers are analyzed.

Research of busbar protection s logic on dead-zone fault of coupler;

According to the principle of BP-2B bus differential protection,filed bus wiring and power flow direction of 500 kV Gangcheng Substation under Zhanjiang Power Supply Bureau,the paper compares the effects of actuating bus separation pressboard on bus differential protection during bus fault and dead-zone fault in different cases.

This paper introduces the configuration of bus protection in dual-bus dual-subsection connection,and puts emphasis on analysis of action of bus differential protection in bus coupling breakers or sectional switches malfunction and dead-zone fault,and also expounds the differences between bus coupling breaker malfunction and sectional switch malfunction.