Integration of Distributed Energy Resources in Low Voltage Electricity Networks

The introduction of distributed energy resources (DER) is leading to significant changes in the way in which power systems are planned, operated and maintained. DER includes many different types of technology, ranging from producers of electricity such as microgeneration units to consumers of electricity such as heat pumps and electric vehicles. High penetrations of these new technologies are introducing new challenges for power systems as existing electricity networks were not originally designed to accommodate them. This thesis investigates the potential impact of DER in distribution systems, in particular low voltage residential networks, in terms of end-user voltage levels and thermal loading of network equipment. Deterministic and stochastic methods are used to analyse low voltage residential test networks. Acceptable penetration levels of various DER technology are assessed while maintaining the network within permissible operating limits. A stochastic assessment of the network with various penetration levels of DER is also performed to incorporate a number of the uncertainties associated with DER, such as time-of-use and energy requirements. In order to accommodate high penetrations of DER on existing low voltage distribution networks, a method for controlling their operation in a coordinated manner is proposed. The method controls the operation of DER units in order to fully utilise the available capacity of the network while maintaining acceptable operating limits. While