The use of static plant to reduce the effects of system disturbances

The concept of electromagnetic compatibility (EMC) has begun to gain acceptance. This seeks to ensure that electric plant is designed to be immune to certain reasonable levels of disturbance and that, on the other hand, its emission of disturbances is limited to an appropriate level for its size and situation. Disturbances to the system voltage may be regular or irregular and may affect amplitude, waveshape and frequency. The author discusses various forms of disturbance and the different types of equipment to overcome them. In particular the author discusses loss of power supply, system frequency variation, static VAr compensators, waveform distortion, harmonic filters, and short-circuit current limiters