Analysis and mitigation of transient overvoltage with integration of small scale power-electronic interfaced DG

As the amount of non-scheduled small scale distributed generation (DG) units are increasing, lack of fault ride through (FRT) capability of these generators may have an adverse affect on the overall power system. This study focuses on the basics of transient overvoltage issue arising under faulty condition with integration of power-electronic (PE) interface based DG units in a system. Reasons behind this overvoltage issue and its impact on DG integration with present grid standard have been investigated. A methodology has been utilized to overcome this overvoltage issue in a system, which has conventional generator as well as wide penetration of full-converter based solar and wind generation. An IEEE industrial test system with varieties of motor loads has been used to carry out the analysis and to verify the methodology.