Coordinated control of energy storage devices and photovoltaic inverters for voltage regulation based on multi-agent system

Distributed photovoltaic (PV) integration with high penetration has resulted in increasing problems of overvoltage and undervoltage in low-voltage (LV) distribution networks. This paper proposes a coordinated control scheme of energy storage devices and PV inverters to solve the voltage rise/drop issues. And the scheme is guided by voltage-power sensitivity. When the voltage exceeds the upper limit, the energy storage devices are charged instead of curtailing the active power of PV inverters, and the stored energy is discharged after making use of the reactive power of PV inverters when the voltage is less than the lower limit. What's more, in view of the situation that the number of monitoring devices is much smaller than that of network nodes, a voltage estimation algorithm is proposed, in which the feeder is divided into multiple regions and the voltage extremums of each region are estimated on the basis of voltage drop theory. Both voltage estimation algorithm and regulation scheme are implemented by a multi-agent system with a redundant communication scheme to improving the reliability. Finally, the proposed method is evaluated in a LV distribution network model in Matlab, and the results verify the effectiveness.