Use of Integrated Photovoltaic-Electric Spring System as a Power Balancer in Power Distribution Networks

Electric springs (ES) have been proposed as a demand-response technology for improving the stability and power quality of emerging power systems with high penetration of intermittent renewable energy sources. Existing ES applications mainly involve the regulations of grid voltage and utility frequency. This paper reports a power control and balancing technique for a new integrated configuration of ES and photovoltaic (PV) system, and discusses its possible use to achieve dynamic supply-demand balance in power distribution networks. The proposed system enables delivery of maximally harvested PV power to the grid via the ES, and concurrently controls the active power consumption of its ES-associated smart load so as to achieve supply-demand power balance of the overall system in real time. Importantly, battery storage is not necessary in the proposed design because the ES-associated smart-load power follows an appropriate consumption profile to compensate potential prediction errors of the PV power generation. Both simulation and experimental results are included to validate the proposed ES system.