Determining the actual benefits of Volt/Var Optimization

If feeder loading and operating conditions were very consistent from day to day, determining the benefits of a Volt/Var Optimization (VVO) scheme operating in the distribution system would be a simple matter of comparing the results with VVO on and off. However, the electrical conditions of every feeder can vary significantly from day to day which makes this problem challenging. This paper presents different methodologies for the evaluation of effectiveness of a VVO scheme when the data with VVO scheme on and off are available. The presented methods differ in a way they treat variables, other than the status of the VVO scheme, that affect energy consumption and load demand, such as weather, day of week, time of day, etc. The effectiveness of a VVO scheme is expressed in terms of saved kWh and reduced peak demand per reduction in voltage delivered to the load. Other indicators include improvement in power factor and quality of voltage delivered to the customers.