Research On Substation Area Construction Mode And Control Strategy

At present,the control system of substations is decentralized and independent.There are many problems such excessive equipment,high cost,with heavy operation maintenance workload.And it is difficult to give full play to the technical advantage of substation-area information sharing.The promotion and improvement of the control system is limited.With the development of power system,in particularly with the large-scale access of new energy source and the widly application of AC/DC hybrid transmission technology,there are many new and higher requirements for the substation control system.Therefore,combined with the technical features of intelligent substation,deeply develop researching on substion control system based on substation-area information.It has important theoretical and practical significance to ensure the safe and stable operation of power system and improve the reliability of power supply.This paper mainly researchs on the constucton mode and control stategy of substation control system,such as automatic switchover,under frequency and under voltage load shedding,reactive power and voltage control.In the research of construction mode of substation-are control system,considering the technical features and information requirements of substation control function,the design principle and function configuration scheme of the substation control system are put forward.On the basis,combined with the technical development of protection and system protection,this paper puts forward two construction modes inorde to meet the requirements of different engineering applications.One mode integrates substation control system with substation protection system,the other mode desigens substation control system independently.In the research on substation-area automatic switchover,a general automatic switchover based on substation-area information is proposed in order to solve the problems of too many sorts of automatic switchover and the difficulty to adapt to various operation mode of power system.The method takes the basic unit of automatic switchover as the core.Through reasonable combination of the basic unit,the required automatic switchover modes under various operation mode are formed.At the same time,by using the switch state information and current information of branchs,the operation mode of the substation can be on-line indetified.Based on the result of on-line ubdetufication,the automatic switchover function is adjusted in order to improve the self-adaptive capability.In addition,according to the problems of traditional automatic switchover such as adaption to security and stable control system,distributed generation access and over load causing by automatic switchover,an imporved automatic switchover control stategy is proposed which based on substation-area information.It can improve the control proformance of automatic switchover under different operating conditions.In the research on under frequency and under voltage load shedding,this paper presents a scheme of load shedding optimization method.The method measures and calculatses the real time load level on line.Comprehensive considering the effects of the importance of outgoing lines,the autoregulator of loads,and other factors,the model is solved by partial exhaustive method,and the load shedding line is determined.On the basis of ensuring the load shedding,it can improve the accuracy of load shedding and the power supply reliability of the important load.In the research on reactive power and voltage control,in order to solve the problem of traditional nine-area method is not considered the coupling of reactive power and voltage,a reactive power and voltage control method based on five-area is adapted.At the same time,the function is transferred from the traditional substation level to the bay level.It is realized by substation-area control system in bay level in order to improve the response speed and reliability of reactive power and voltage control.In the substation-area control system,the fault line selection function is integrated to reduce the equipment cost.In this paper,the fault line selection method of the neutral point grounded by arc suppression coil is studied.A fault line selection method based on information fusion technology is proposed.The method makes use of steady state information and transient information for fault line selection to improve the accuracy and reliability.In addition,according to the actual application requirements of the project,according to the proposed method and the optimal control strategy of substation-area automatic switchover,the software program is developed.And the method is simulatied by using C language and PSCAD.The correctness of program and the performance of the methe are verified by thedigital simulation results.Finally,the work of this paper is summarized and the future work is prospected.