Basis for a Wireless Network for EMC Measurements in Electric Substations

Switching operations of power equipment such as disconnect switch and circuit breakers in high voltage substations produce high frequency transient currents, which propagate along the busbars. The busbars then act as antennae, producing transient electromagnetic fields in the switchyards. In electromagnetic compatibility (EMC) considerations, the resulting fields are important sources of electromagnetic interference (EMI); moreover, highly sophisticated, new technology equipment are being introduced into substation environment for measurement, control, protection and communication purposes. These equipment are located close to other switching equipment in switchyards. Hence, to establish the electromagnetic compatibility of the electronic equipment, it is desirable to quantify the high voltage environment. This paper describes a new digital wireless measurement system that is based on bluetooth technology and which could be used in power stations or other similar harsh environment. It comprises a remote acquisition unit (RAU), a wireless data communication network (WDCN) and a PC-based control platform. The performance and capability of the system was assessed against another measurement system based on fiber optics technology and was found to be more portable, easier to install and cheaper. The limitations of the wireless system are considered and ways of addressing them in the future are discussed.