Management of Voltage Dip Performance for Large Industrial Customers

- In the management of Power Quality to customers, voltage dip performance has often been done on the basis of contracted or regulatory voltage dip limits [3]. In South Africa, such limits were statistically derived for various voltage levels using (limited) data available for all measured sites in South Africa over a period of a few years. A very different approach was introduced by the National Energy Regulator of South Africa in 2003 [1] Under a framework agreed by all stakeholders, licensees are required to implement a Power Quality Management System which focuses on "continued improvement" through the interaction between the licensee and its customers based on more transparent communication on the causes and impacts on customers (including financial impacts) of such events. This paper discusses these two approaches in managing voltage dips - i.e. (1) contractual dip performance or regulatory minimum standards vs. (2) "continuous improvement" that underlies the new South African framework. Emphasis is placed on the benefits gained from utilising active interaction and the impact this has on the relationship between utility and customer. Specific case studies investigating the implementation of the PQMS with large industrial customers are discussed.