Voltage Control in LV Networks Using Electric Springs with Coordination

Abstract

The increasing use of distributed generation like rooftop solar panels and charging of large fleets of electric vehicles will result in over-and under-voltage problems in the low voltage (LV) distribution networks. Distributed electric springs have been proposed as an effective way of controlling these voltage problems. However, when multiple distributed electric springs are activated in a system, each electric spring tries to correct the local voltage problem. As a result, two groups of electric springs located in two different sections of the same radial network can be competing against each other at any given time. In the past, droop control has been suggested as a solution to avoid this conflict. This paper highlights the problem with simple drop control of electric springs in a radial distribution network and presents coordination between electric springs as an alternative. A comparison between the droop control and the coordinated droop control option is presented in terms of their voltage control capability, and required compensator capacity. It is established by means of a case study on a typical European LV network with stochastic demand profile for different types of residential customers.