大容量抽水蓄能发电机断路器发热特性仿真与散热优化方法

Heating Characteristic Simulation and Heat Dissipation Optimization Design of Pumped Storage Circuit Breaker

过高的温升会加速真空断路器结构老化、降低机械强度,基于温升仿真分析的断路器散热优化设计对断路器性能提升具有重要意义。为此通过建立大容量抽水蓄能发电机断路器电磁仿真模型,计算不同通流情况下的电磁损耗,并基于各端面接触电阻损耗,获得总发热损耗参数。在此基础上,建立包含对流、传导、辐射热传递模式的断路器自然对流仿真模型,从增强自然对流、辐射两方面对断路器散热结构进行优化设计。研究结果表明,在通流12.5 kA情况下,断路器监测点最高温升为133.7 K,辐射功率占比约23%。通过增加散热片及热管,最高温升能够降低至109.5 K。增大断路器部件表面发射率能够低成本实现辐射功率提升,从而将最高温升进一步降低至96.9 K。通过断路器稳态通流温升实验,验证了仿真可靠性,监测点温升的仿真与实验平均误差小于2.1 K。

Excessive temperature rise will accelerate the aging of vacuum circuit breakers and reduce mechanical strength.The heat dissipation optimization design of circuit breakers is of great significance to the stable operation of circuit breakers.Therefore,the electromagnetic simulation model of circuit breaker using for large capacity pumped storage was established.The electromagnetic loss of 12.5 kA was calculated.The total loss based on the contact resistance was obtained.A natural convection simulation model of circuit breaker including considering convection,conduction,and radiation was established.Then the heat dissipation structure of circuit breaker was designed and optimized to enhance natural convection and radiation.The results show that the maximum temperature rise of the circuit breaker is 133.7 K under the conduction current of 12.5 kA,and the radiation power accounts for 23%.By adding heat sinks and heat pipes,the maximum temperature rise can be reduced to 109.5 K.Increasing the surface emissivity of the circuit breaker component can achieve a low-cost radiation power increase and further reduce the maximum temperature rise to 96.9 K.Finally,the reliability of the simulation results is verified by carrying out the steady-state current temperature rise experiment of the circuit breaker.The average error between the simulation and experiment of the temperature rise of the monitoring point is less than 2.1 K.