The optimal selection of mitigation methods against voltage dips and interruptions: a customer-based approach

Voltage dips and interruptions cause major economic damage. Not only do we have to consider potential loss of production, there is also loss of market, the loss of client thrust, comfort,... that make the energy consumers want to implement a certain form of protection for their systems. However, the abundance of available mitigation methods and the, in many cases, unknown interruption cost make the selection of the most cost-effective mitigation method very difficult. This optimal mitigation method cannot be calculated using traditional theoretical economic methods, and is not always obtained by the currently used selection methods in the industry. However, using an alternative selection method, an optimal mitigation method can be found. This paper describes the steps to be taken, to solve the selection problem by means of a practical example. The examined case is a 250 kVA installation with a high sensitivity to voltage dips (pc load), and without a full knowledge of the cost of a process interruption. The proposed method makes a cost-benefit analysis of all possible solutions resulting in an overview that gives the optimal solution for a certain interruption cost. This method makes it possible to clearly interpret the investment costs and to compare completely different mitigation methods, only using data and methods which are available to an industrial customer. As such, this paper is written from a customer point of view.