Economic Assessment Of Voltage Sag Based On Quality Engineering Theory

In power markets, power quality (PQ) problem is attached more and more importance. Voltage sag, as the most important PQ problems, may cause huge financial loss, which needs scientific method to evaluate. This paper introduces the quality loss function, signal-to-noise ratio (SNR) and quality cost in quality engineering theory to assess it. The proposed integrative economic loss function is based on the inverted normal probability loss function and SNR. Also, the concept of index of sag-caused loss is put forward, which is an important parameter for PQ evaluation. The steps of the elimination technology choice from the engineering viewpoint are brought forward. The improved quality cost model is proposed to choose the reasonable PQ elimination scheme. The simulated results show that this method could effectively assess financial losses caused by voltage sag and choose reasonable elimination technique which meets both economic and technical demands. Also the proposed approach would be an effective theoretic instruction for power quality evaluation, elimination and pricing.