Analysis of Three-Phase to Five-Phase System Under Unbalance condition

Abstract

Multi-phase (more than three phase) is being increasingly used in many applications. Due to higher phase numbers, there is more possibility for a multi-phase system to have unbalancing between different phase voltages in comparison to a three-phase system. Performance and behaviour of a multi-phase system under unbalance condition is of much importance. Conversion of an unbalanced system to a balanced system was proposed by C. L. Fortescue and balanced components was given the name ‘‘symmetrical components In this paper three-to-five phase transformation has been analysed under various unbalanced conditions using simulation and experimental analysis. Symmetrical components transformation of a five-phase system is presented and determination of active and reactive power with the help of symmetrical components is developed. Furthermore, sequence circuit of three-to-five phase transformation is developed to model various operating conditions. With this modelling, the degree and nature of different unbalances and their effects on the system can be predicted in advance. Both simulation and laboratory tests results for a three-to-five-phase transformation is presented. It has been concluded that experimental results are well in line with the analytical results.