Single-phase static converters for rural distribution system

This work presents the development of four-wire single-phase to three-phase static converters for rural distribution system. Component specification guidelines and control strategies of two proposed topologies are described. Both converters are based on a front-end half-controlled PWM rectifier that handles the DC bus voltage regulation as well as reduces the input current distortion. In order to provide three-phase four-wire system, two basic inverter topologies are considered: three-leg PWM-VSI with split DC link capacitors and four-leg PWM-VSI. Complete models are implemented in an electromagnetic transient simulation package (PSCAD/EMTDC ), where each converter is connected to a typical rural distribution network and supplies three-phase unbalanced loads. Performance analysis based on simulation results is carried out considering the occurrence of voltage sags.