In this paper, the geometry-electromagnetic character, thermal condition of the coils, and encapsulation number are coupled in the optimization design of an air core reactor, to realize the minimum usage of metal conductor. Combined with the equality constraint conditions for maximum temperature rise conservation, inductance conservation, and structure function of the reactor, the optimization design curves and results are achieved based on the initial design parameters. According to the design results, the temperature field simulation model of the reactor is established, and the results verify the correctness of the optimization method. Compared with the design method of 'equal height and heat flux' and thermal-electromagnetic character without considering the change of encapsulation number, the proportionality factor of metal conductor usage is 0.73 with the optimization method. It shows that the optimization method can significantly improve the utilization ratio of the conductor. Meanwhile, the influence of regularity on the electromagnetic efficiency, thermal efficiency, and other parameters is also obtained.

As one of the key technologies to solve the problem of high short-circuit current, the fault current limiter (FCL) has become a research hotspot in China and abroad. The overvoltage and protection measures of the FCL are the key technologies for its application. Therefore, this paper studies the lightning intruding overvoltage and protection measures for a 500 kV FCL based on a high coupled split reactor (HCSR). Firstly, according to the main topology of the system and the 500 kV HCSR-FCL structure, the lightning intruding overvoltage simulation model of the 500 kV station, including the nearby transmission lines, is established on the PSCAD (Power Systems Computer Aided Design) program. Secondly, the lightning overvoltage of the equipment in the station and the components of the HCSR-FCL are simulated and analyzed when the transmission lines nearby are subjected to lightning shielding failure and back flashover. Meanwhile, the influence of the HCSR-FCL on the lightning overvoltage of the equipment in the station are compared and analyzed before and after the HCSR-FCL is installed. The simulation results show that the overvoltage of the equipment in the station and the components of the HCSR-FCL is more serious when the shielding failure occurs in the transmission lines nearby. The HCSR-FCL can reduce the lightning overvoltage of the equipment in the station, but the maximum inter-terminal and inter-arm lightning overvoltage of the HCSR can reach 1064 kV and 790 kV, respectively, under the current limiting state and the current sharing state. Finally, methods of increasing the arresters on the transmission lines side of the HCSR-FCL and shunt capacitor between each module of the HCSR-FCL are proposed to reduce the lightning overvoltage. The lightning impulse withstand voltage of each component of the HCSR is also proposed: The inter-terminal lightning impulse withstand voltage of HCSR is 170 kV. The inter-arm lightning impulse withstand voltage of HCSR is 200 kV. The terminal-to-ground lightning impulse withstand voltage of the HCSR-FCL is 1550 kV.

No abstract

No abstract

No abstract