Distributed automatic voltage control (DAVC)

The use of reactive power control as a means of controlling voltages in low-voltage (230 V/400 V) distribution networks is considered. The proposal is to use spare capacity in power electronic interfaces such as inverters in domestic photovoltaic (PV) and micro combined heat and power (CHP) units to generate or consume reactive power according to locally measured voltage. This Distributed Automatic Voltage Control (DAVC) is proposed as a means of allowing greater penetration of low-carbon technologies into existing distribution systems. A detailed model of a real distribution system in the UK has been used to determine that DAVC can be effective in controlling voltages despite the low X-upon-R ratio typical of low-voltage distribution networks. A slight increase in network losses is predicted but this could be justified by the allowance of a greater penetration of PV and a reduced need to curtail its generation due to network voltage rise. A significant reduction in source power factor is also noted.