匝间短路故障下干式空心电抗器电动力仿真研究

Study on Simulation of Electrodynamic Force in Dry-type Air-core Reactor Under Interturn Short Circuit Fault

干式空心电抗器运行过程中,由电动力引起的振动现象是其发生匝间短路故障的主要原因之一。为进一步研究电抗器匝间短路故障时电动力分布,利用有限元软件建立了5包封电抗器场-路耦合模型,对正常运行以及发生匝间短路故障的干式空心电抗器的磁场、电流以及电动力分布进行仿真研究。结果表明:正常运行的干式空心电抗器电动力呈现挤压电抗器的趋势;匝间短路发生时,短路匝内部会流过相位落后其余包封电流90°、幅值极大的短路电流;受短路电流及短路匝附近畸变磁场的影响,短路匝上电动力也会急剧增大,且相位也会发生变化。研究工作全面地揭示了电抗器匝间短路故障下工作状态,对电抗器设计和运维提供了理论参考。

During operation of dry-type air core reactor,the vibration caused by electrodynamic force is one of the main reasons of its interturn short circuit. In order to study further the electrodynamic force distribution of the reactor in the interturn short circuit,the field circuit coupling model of 5-encapsulated reactor is set up by using finite element software so to perform simulation study of the magnetic field,current and electrodynamic force distribution of dry-type air core reactor in normal operation and in the interturn short-circuit condition. The results show that the electrodynamic force of dry-type air core reactor in normal operation shows the trend of squeezing reactor. In case of interturn short circuit,the short-circuit current which phase lags other encapsulated current by 90°and the amplitude is extremely large will flow in the short circuit turn. The electrodynamic force on the short circuit turn will,due to to the influence of short circuit current and distortion electromagnetic field near the short circuit turn,increases rapidly and phase will also change. The study work comprehensively reveals the operation condition of the reactor under interturn short circuit and provides theoretical reference for the design,operation and maintenance of the reactor.