Use of Electric Spring System with Adaptive Fuzzy Logic Controller for Power Distribution Networks

Power distribution system is a highly critical infrastructure for modern power grid. In recent years, with the large scale integration of intermittent renewable energy generation which causes instability in the power grid, the power quality problems in distribution system have earned widespread attention. Electric spring (ES), a new smart grid technology, has earlier been used for providing voltage and power stability in a weakly regulated/stand-alone renewable energy source power grid. It has been proposed as a demand-side management technique to provide voltage and power regulation. 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 (RES). Existing ES applications mainly involve the regulations of grid voltage and utility frequency. This project 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. In this project, it was shown that it has good low-voltage ride through ability for system disturbance or unexpected fault. There is also low impact to the utility system in comparison with active detection methods. However, a fuzzy logic control and a more accurate restrain region threshold need to be developed in order to enhance this potential technology for use within future high-penetration networks. Matlab/simulink simulations are presented in order to show the outstanding performance of the proposed design approach.