Comprehensive Evaluation Of Main Electrical Connection In Smart Substation Considering Coordination Between Substation And Power Grid

As the foundation and important support of smart grid, smart substation implements the collection, analysis and sharing of operation data, realizes energy conversion and control, and also acts as the core of strong smart grid construction. Along with the advancement of smart substation, the new generation smart substation which integrates equipment and function has been put forward, impelling the development and application of disconnecting circuit breaker, manifesting the overall integration design concepts and offering greater possibilities of main electrical connection optimization.The present evaluation and selection of main electrical connection only considers the transmission capacity and reliability requirement of substation itself, and ignores the impact between substation and power grid. As substation plays a more important role in power grid, comprehensive evaluation of main electrical connection in smart substation should not only depend on connection forms, but also need to analyze the influence of different main electrical connection schemes on the power gird with consideration of the role and position of substation in the gird.This paper first introduces the reliability analysis model of main electrical connection based on fault combination algorithm, and proposes corresponding evaluation indicators of reliability, economy and flexibility. Combined with the technical characteristics and applications of disconnecting circuit breaker, the effect of this integrated equipment on main electrical connection optimization is analysed. Then, the model of comprehensive evaluation of main electrical connection considering coordination between substation and power grid is established in this paper. Main electrical connection in substation is included in the grid simulation, and fast topology analysis methods are put forward. Besides, power flow calculation and load shedding strategy is illustrated. Thus, evaluation and optimal selection of main electrical connection schemes is realized based on reliable and economic performance of power grid including substation connection. At last, for the typical design schemes of smart substation, this paper comprehensively evaluates different connection forms with conventional equipment and disconnecting circuit breaker, and the results confirm the feasibility of main electrical connection optimization with disconnecting circuit breaker. Taking the IEEE-RBTS and the IEEE-RTS 79 for example, this paper calculates the reliability indicators of power grid which considers the influence of main electrical connection, and the results validate the rationality of power grid analysis model including substation connection. Based on this model, different main electrical connection schemes with disconnecting circuit breaker in each substation of IEEE-RTS79 are comprehensively evaluated by reliable and economic indicators and the optimal scheme is selected.