This paper analyzes a 220kV main and auxiliary bus Ⅱ section bus trip accident in a 500kV substation.Through the inspection of primary equipment and secondary equipment, combined with the on-site processing conditions such as the inspection of the knife switch body, the test opening and closing inspection, and the inspection of the state of the switch, the opening principle of the accident knife switch is studied.It was found that the cause of the accident was the jamming of the transmission parts and the contamination between the dynamic and static contacts, which caused the failure of the switch to open.In addition, the position of the switch is wrongly judged, and the dynamic and static contacts of the main bus switch are in virtual connection, causing arc discharge and tripping of the bus differential protection action.In response to such accidents, this paper proposes to carry out the 220kV busbar reconstruction project to realize the optimization and reinforcement of local grids and other follow-up measures.In order to solve the problem of unstable grid structure after connecting to multiple substations in the same section of 220kV busbar of similar 500kV substation, improve the reliability of power supply and ensure the stable operation of the power grid.

为实现高精度的多自由度超声波电动机控制,提出一种新型的基于压力传感器的电机力矩测试机构,并阐述了测试原理和方法.实验证明,该测试机构满足电机力矩的测试要求,具有精度高、结构巧妙和体积紧凑等特点.

For the inequality of capacitance current and testing voltage of various equipments,the test of AC withstanding voltage of power plant's electrical equipment requires four or more testing transformers with different models and capacity volumes. The different capacity volumes of transformers lead to limited scope of applications and low efficiency of devices. A method of incomplete resonance at the power-frequency is put forward to complete the test of AC withstanding voltage of power plant's medium-voltage electrical equipment.