APPLICATION OF A CORRECTION CURRENT INJECTION POWER FLOW ALGORITHM TO AN UNBALANCED 4-WIRE DISTRIBUTION NETWORK INCORPORATING TN-C-S EARTHING

Power flow analysis of distribution networks incorporating Low Voltage (LV) consumer representations needs to be cognisant of both a highly unbalanced load structure as well as the provision of the grounding network between the consumer and grid operator (TN-C-S earthing). In this paper, the asymmetrical 3-phase (plus neutral) power flow problem is solved by a correction current injection method using a complex Y matrix approach in consideration of a representative Irish urban distribution network. This methodology offers a much improved and more robust alternative for ill-conditioned asymmetrical network scenarios compared to the standard power flow methodologies such as the Newton-Raphson methods or the forward-backward sweep approach (which encounters convergence issues as a consequence of the complex earthing arrangements). The model refers to a 4-wire representation of a suburban distribution network within Dublin city, Ireland, which incorporates consumer connections at single-phase (230V-N). Investigations relating to a range of network issues are presented. More specifically, network issues considered include voltage unbalance/rise and the network neutral earth voltage (NEV) for increasing levels of micro/small wind generation technologies with respect to a modeled urban wind resource.