Reliability Evaluation Of Substation Bus Arrangements Considering Economical Operation Of Transformer

Power system reliability is the capacity that refers to uninterrupted power and electricity supply, also it ensure the acceptable quality standards and the required number of metrics for users. Power system reliability included abundant intensity and security. Abundant intensity, known as static reliability, is the ability of power system to meet the demand of electricity and electric energy under the static conditions. Security is called dynamic reliability, which endureed sudden disturbances power system and uninterrupted provide electricity and electric energy to users in the dynamic conditions. The economy and reliability of substation were mutual restrictive, and increased investment can enhance reliability, but the economy was constrsinted by the high investmen.The main electrical connection is the main part of electrical substation, and it is an integral part of the channel in power transmission power system. Its connection way is playing important role to transformer substation by itself in current supply reliability, flexibility of controller and rationality in economy.The transformer load factor of the economy were analysized, the way of economic operation of transformer were considered. The reliability of electrical equipment which involved in the main electrical were studied under the situation that the reliability of electrical equipment components and the types of electrical main connection parameters were be known; the combination of electrical equipment in the actual running state of the system components to simplify and mergers were considered; the non-expansion type of failure to create a new four-state model were established by using of the expansion of electrical equipment failures. In this paper, the system reliability of four common main electrical connection were analyzed by ueing Markov equation to calculate the reliability parameters for electrical equipment and the fault tree analysis of analytical method.To compare the single transformer to wiring, the system reliability of two transformers were parallel operated has improved significantly in increasing electrical power transformer of the main terminal. The annual investment and equivalent cost of power outage losses were calculated, aiming at four kinds of main electrical wiring, the change of investment after single and two transformers are parallel operating in the four kindsof the main electrical wiring were analyzed,and the spare transformers on the system power outage losses improvement was increased. If the increased transformer and the original transformer were parallel operated and reserved for each other, the economy will be significantly improved in power system. The system reliability and flexibility of scheduling has significantly improved with increasing of the power transformer.they provide a choice for the engineers to design new transforming station and the old station.