GENERATION CONTROL SCHEMES FOR PREVENTING OVERLOADING OF EHV SUBSTATION MAIN TRANSFORMER

摘要

The main purpose of this paper is to study the control of power plant generation under outage of main transformer in the adjoining substation. The control of power plant generation aims to prevent overloading of the remaining transformer and hence to maintain system operation security. The proposed control methods include two schemes of operation on the generating units: Direct Transfer Trip (DTT) and Generation Reduction (GR). A sample local power system with an EHV substation and two generation plants is investigated and thus the two control schemes are illustrated by analyzing system power flow and system dynamics. It is found that, in view of preventing substation transformers from overloading, the DTT scheme results in a better system performance than the GR scheme does.