直流融冰装置测试用等效模拟负载的温升计算与试验

Experiment and Calculation of Temperature Rise of Equivalent Simulation Load Used in DC De-icer Equipment Test

直流融冰技术是电网防御冰灾的重要技术。现有的直流融冰装置性能检测主要进行短路或开路试验,无法完全模拟实际运行条件下的融冰状态。为了设计直流融冰装置全压大电流试验中所用的模拟负载,以10 MW直流融冰装置为例,根据传热学和计算流体力学（CFD）的基本理论,以水作为模拟负载的导电和散热介质,建立功率1/100的缩比负载的物理模型。采用有限元方法对缩比模型的流场分布和温升进行了数值仿真计算,并开展等效物理试验测量负载模型的温升。最后,根据单台直流融冰装置的实际功率要求,设计了全压大电流负载装置的电气结构及散热方式。结果表明：模拟负载装置以17 m3/h作为入口流速,可以满足极板温升70℃的设计要求值,验证了以水电阻作为直流融冰装置试验的等效模拟负载的可行性。

DC de-icer technology is an important technology to defense ice disaster in power grids. In the process of the existing DC de-icer performance tests, open-circuit voltage or short-circuit current alone is taken as detection object, which can not simulate the real ice-melting conditions totally. To design simulation load used in DC de-icer test with full voltage and high current, a 10 MW DC de-icer was taken as an example. Based on the computational fluid dynamics（CFD） and the heat transfer theory, a 1/100 scaled power simulation load was designed, using water as conductive and cooling medium for the simulation load. Then, the fluid field distribution and temperature rise of scaled model were calculated by using the finite element method, and the confirmatory physical tests were conducted to measure the temperature rise of load device. At last, according to the actual power requirements of a DC de-icer, the electrical structure and heat dissipation of full-voltage and high-current load device were designed. The results show that the temperature rise of electrodes can meet the design requirements of 70 ℃, where the inlet flow rate of simulation load reaches 17 m3/h. The feasibility of equivalent simulation load in DC de-icer test using water medium is verified.