Community Energy Storage for Neutral Voltage Rise Mitigation in Four-Wire Multigrounded LV Feeders With Unbalanced Solar PV Allocation

The traditional neutral voltage problem in low-voltage (LV) four-wire multigrounded distribution networks can be aggravated due to an unbalanced allocation of one-phase photovoltaic (PV) units. Inherent limitations restrict the performance of the traditional strategies to mitigate the combined effect of load and PV unbalance. To overcome the shortcoming of traditional approaches, a new dynamic mitigation approach using community energy storage (CES) is proposed in this paper. A power balancing algorithm is developed to perform the balancing operation while minimizing power drawn from the CES. A charge/discharge control strategy is developed that will continuously balance and dynamically adjust the power exchange with the grid in a real time, and mitigate the neutral current and neutral voltage rise. To investigate the applicability of the proposed approach under physical time delays associated with battery and PV systems, a suitable dynamic model is developed. An Australian LV distribution system is used to verify the proposed approach under daylong variations of load and PV, and also during short-term variations of PV output caused by cloud passing.