Fundamental concepts of regulating distribution system voltages

A power distribution system distributes power from a substation to the point of power utilization. Voltage drops occur naturally on distribution systems. It is designed to keep the voltages near the nominal values, and usually within a few percent limit. Besides load balancing, electric utilities commonly use both voltage regulators and shunt capacitors to maintain voltages within the design limits. This paper addresses what factors to be considered when deciding whether regulators, capacitors, or load balancing or a combination is most appropriate to provide the needed voltage support