Synthetic grading evaluation of power quality based on cask principle

In a liberalized electricity market, it is not surprising that different customers need different power quality level with different price. So how to define a synthetic grading evaluation of power quality (PQSGE) became a concerned problem. In this paper, based on four electromagnetic compatibility (EMC) levels, all individual indices of power quality(PQ) were divided into five classes (Class I -Class V); On this basis, a novel PQSGE method based on cask principle was represented, which is easily understood and manipulated by operators, customers and regulators. A case study based on actual monitoring data of PQ showed that the overall quality levels of the assessed site qualitatively reflected the levels of electromagnetic environment and also expressed the characteristics of loads served by the site. The PQSGE can work together with the market mechanism of future electricity market to promote utilities and end-users to improve the overall level of PQ, reduce the whole socio-economic losses caused by power disturbances and ultimately support a future digital society.