Modelling of voltage regulation issues in SWER systems using PSCAD/EMTDC

An economic (low-cost) distribution system, called Single Wire Earth Return (SWER), has been used extensively in remote parts of Queensland and other states of Australia to deliver electrical energy to small customer loads, scattered sparsely over vast areas. Ergon Energy Corporation, a distribution utility in Queensland, has identified voltage regulation as one of the key issues being faced in this area, as loads continue to grow in rural distribution networks. In order to study voltage regulation issues of these systems, suitable models must be developed.Commercial software packages which are currently used by Ergon Energy, such as DINIS and PSS Adept do not offer all features required for modeling the SWER distribution systems in complete detail. Therefore, custom modeling using more flexible software tools available is deemed necessary. One such a software tool is PSCAD/EMTDC (PSCAD) developed by the Manitoba HVDC Research Centre in Canada. This is a commercial software package based on similar algorithms to most common electromagnetic transient programs such as EMTP or ATP.In this paper, modelling of SWER systems using PSCAD is discussed. Building blocks for the models of the distribution system components are developed. The effectiveness of this modelling approach is demonstrated using case studies of a real SWER distribution system. By using these models, the voltage regulation problem and the suitability of the proposed voltage control methods can be studied for a large network.