Hardware Realization of a Residential Static Var Compensator

Conservation by Voltage Reduction (CVR) is the implementation of a distribution voltage strategy whereby all distribution voltages are lowered to the minimum allowed by the equipment manufacturer. This strategy is rooted in the fact that many loads consume less power when they are fed with a voltage lower than nominal. Electric utility companies consider CVR as a potential solution for managing power in distribution networks. However, a difficult challenge is to keep end-of-line (EOL) voltages within an acceptable range of the ANSI Standard C84.1. Therefore, to achieve maximum benefit from CVR, electric utilities should be able to regulate residential voltages depending on load requirements. Hence, there is a need for a local solution which can regulate residential voltage levels from the first customer on the distribution feeder until the EOL of the distribution network. Such a solution will not only provide flexibility to electric utilities for better control over residential voltages but it can also maximize the benefits from CVR. The goal of this research is to develop a Residential Static Var Compensator (RSVC) that will allow electric utility companies to develop strategies for CVR and other applications. The proposed RSVC is in fact a reactive power compensator that can regulate a residential load voltage with a fixed capacitor in shunt with a reactor controlled by two bidirectional switches. The two switches are turned on and off in a complementary manner using a pulse-width modulation (PWM) technique that allows the reactor to function as a continuously-variable inductor. The proposed vii RSVC has several advantages compared to a conventional thyristor-based static var compensator (SVC), such as a quasi-sinusoidal inductor current, sub-cycle reactive power controllability, lower footprint for reactive components, and its realization as a single-phase device.