Investigating the impact of embedded generation on relay settingsof utilities electrical feeders

摘要

Since the late 1970s, intensive efforts have been made to utilizenrenewable energy sources to generate electric power. On the other hand,neconomical pressure experienced in recent years has led to thendevelopment of high efficiency combined heat and power schemes to usenthe normally wasted heat to generate electric power. Generators usednunder both schemes can be either synchronous or asynchronous types andnwhen they are integrated into utilities' distribution networks (DNs)nthey are commonly known as “embedded generators” (EGs).nPrevious experience has shown that the integration of EGs into DNs couldncreate safety and technical problems. They may contribute to faultncurrents, cause voltage flicker, interfere with the process of voltagencontrol, etc. This paper reports an investigation to determine thenimpact of the integration of EGs on the settings of protective devicesnof electrical feeders emanated from the substation to which EGs arenconnected. This study also covers the dynamic behavior of EG caused byndisturbances on the host network. Results obtained from several casenstudies presented and discussed