Research And Design Of 220kV Automatic Switch Device In 500kV Substation

With the rapid development of power system, access to large capacity power generating units, new transmission lines and substations investment, it will inevitably lead to sustained growth of short circuit current, resulting in the problem of 500kV ’substation 220kV side bus short-circuit current exceeding. Open loop operation mode in 220kV side system is a kind of important short-circuit current limiting measures, but it will put a great impact on the reliability of the power grid. Needing to install the automatic switch device, so that the 220kV side system when the main power is lost can put into standby power supply to ensure the reliability of power supply. Therefore, this paper focuses on the research, design and application of 220kV side system automatic switch device in 500kV substation.Firstly, according to the analysis of 220kV side connection mode and operation characteristic in 500kV substation, the design ideas of auto-switch mode are presented. Auto-switch mode is the basis of the design of automatic switch device. According to the auto-switch design criterion and the main connection mode, the basic principle of using the main transformer as the main power supply and bus coupler circuit breaker as auto-switch circuit breaker is determined. By comparing with the conventional HOkV and the following medium and low pressure automatic switch devices, determine the auto-switch mode based on main transformer tripping starting criteria, combination of checking without pressure and checking the same period, priority setting.Secondly, according to the 220kV side of the 500kV substation auto-switch mode, put forward the functional requirements of the automatic switch device, complete the hardware design ideas, give the plug-in type of hardware design. Combined with the specific functional requirements and configuration requirements of the key plug-ins, the corresponding requirements analysis was carried out to determine the type of device selection. On the basis of this, it discusses the harm of electromagnetic compatibility and electromagnetic interference to each hardware plug-in, and puts forward the corresponding anti-interference measures.Thirdly, according to the implementation logic of each function of the equipment, the design of software program is completed. The software program design includes the main program design, the sampling interrupt service subroutine design and the fault processing program design. Through the analysis of the commonly used data algorithm, the Fu Liye algorithm is selected as the sampling interrupt service subroutine. On the basis of 220kV side system auto-switch mode, detailed design of fault handling procedures, and the core of the starting logic criterion, charging logic criterion and discharge logic logic diagram design criterion.Finally, the paper summarizes the research and design work of the full text, and discusses the future research and development.