Switching Operation In Substation Research Articles

Characteristic Analysis of Transient Electromagnetic Disturbance Data in Substation

Characteristic analysis of transient electromagnetic disturbance data is very important. In this paper, the time-domain and frequency-domain characteristics of transient electromagnetic disturbance caused by switching operations in substations are analyzed. Two methods are adopted in time-domain analysis. One method is histogram and the other one is normality test. An appropriate procedure for the normality test is proposed. Furthermore, the method used in frequency- domain analysis is to obtain overall envelope. These statistical characteristic analysis methods are showed to be of great value in analyses of the measured samples. The simulation results showed that these methods are effective.

Near field coupling to shielded cable due to switching operation in substation

It is vital to study the electromagnetic coupling to shielded cable for improving electromagnetic antiinterference ability of secondary equipment in a substation. As a hybrid of method of moment (MoM) and transmission line method, a frequency domain model is put forward to study the near field coupling to shielded cable due to the switching operation in substation. Compared with the results of EMTP, the proposed method has been proven correct. Furthermore, this method overcomes the disadvantage of EMTP, which is only applicable for transient analysis of parallel conductors. As an example, the presented method is applied to evaluating the electromagnetic interference (EMI) to the shielded cable, whose shield is grounded at both ends, due to the switching operation in 500 kV air insulation substation (AIS).

Radiated immunity requirements for equipment operational during high-voltage network switching operations

It is well known that EMI arises from any operation that interrupts or changes an electrical current. During switching operations in substations, very fast, high field transients occur which can adversely affect, whether by radiated or conducted interference, the electronic equipment in equipment rooms unless it is adequately protected. The environment in which this equipment is installed therefore needs to be fully characterised in terms of electromagnetic interference levels. With this knowledge it is possible to provide adequate immunity for electronic equipment, and design efficient, effective and reliable protection, control and monitoring systems. The paper identifies two areas where the IEC 61000-4-10 Standard appears to be deficient. These are the required test frequencies of 10 kHz and 10 MHz, and testing at these frequencies are recommended at a repetition rate as determined by the formula given in the Standard.