CONTROL TECHNIQUE FOR CONVERTER-CONNECTED SMALL SCALE EMBEDDED GENERATION

Abstract

Small-scale embedded generation (SSEG) often generate direct current (DC) that is typically converted to alternating current for practical purposes as most modern uses of electricity require alternating current (AC). This conversion usually achieved through power electronic converters. Control of these converters is needed because SSEG installations may include a mix of SSEGs interfaced via single or three-phase converters, which may give rise to voltage unbalance problems. Therefore this paper focuses on controlling the power flow from converter-connected SSEG to the load or the distribution network. Control schemes are presented which allow controlling single-phase converter and independently each phase of the three-phase converter-interfaced SSEG during grid connected or stand alone operation. These controllers technique provide additional control flexibility to balance voltages in a distribution network with high penetration of SSEGs. The performance of these controllers is tested and explained using case studies implemented in Power system simulation program (PSCAD).