Advanced power quality rating under the conditions of deregulated markets

The deregulation and the competition on the energy market defy every utility to operate the power system more efficiently and cost-effectively. In order to meet the customers requirements of delivering of energy with different power quality grades becomes more and more important. An energy price scale in line with the expenses for providing a better power quality helps the utilities to optimise their operating costs for the grid and to meet the customers wishes as best as possible. The grade of power quality is defined by the network usage contract. Unless otherwise expressly agreed it is not necessary to prove the power quality all over the line by measurements. However it should be documented by the utility, especially for customers with contractual agreements regarding the power quality. Based on state of the art power quality measurement systems for online monitoring, the presented paper suggests several methods for an enhanced power quality rating. Starting from the rating algorithms provided by actual standards these methods are extended to be more detailed and reliable. Several new quality parameters like planning reserve or quality index are introduced.