脉冲高功率耗能电阻热阻抗模型与系统动态仿真分析

Thermal Impedance Model and System Dynamic Simulation Analysis of Pulsed High Power Dissipation Resistor

直流耗能电阻运行过程中受到脉冲高功率冲击,热特性迥异于目前普遍的稳态发热的电力电子装置,需要采用新的温度计算模型和系统设计方法。为此提出了基于热学原理的温变等效热电模型,讨论分析边界条件、材料属性和尺寸对直流耗能装置温度的影响规律,并提出优化措施。建立了自然冷却和水冷2种方式的直流耗能电阻动态系统仿真模型,其中自然冷却系统采用随温度变化的辐射和自然对流热阻模型,有效提升了模型的精度,并通过试验验证;采用瞬态热源与准稳态冷却系统耦合策略,将直流耗能电阻与水冷冷却系统模型有效集成,进行系统动态仿真分析,并提出直流耗能电阻冷却系统最优功率设计方法。该方法提出的仿真模型和冷却系统设计方法性能优异,满足工程应用需求。

The DC energy dissipating device is subject to instantaneous high-power shocks during operation,and its thermal characteristics are very different from the current steady-state heating power electronic devices.Thus,a new temperature calculation model and system design method are required to be adopted.We propose a thermoelectric equivalent model based on thermal principles,discuss and analyze the influences of boundary conditions,material properties,and diameter on the temperature of a DC energy-consuming device,and propose optimization measures.Moreover,we establish a dynamic system simulation model of DC energy dissipating devices in two modes:natural cooling and water cooling.A model of radiation and natural convection thermal resistance that changes with temperature is used in the natural cooling system,which can effectively improve the accuracy of the model and is verified by experiments.In this paper,a coupling strategy of transient heat source and quasi-steady-state cooling system is used to effectively integrate the DC energy dissipating device with the water-cooled cooling system model,and the system dynamic simulation analysis is performed.Thereby,an optimal power design method of DC energy dissipation device cooling system is proposed.The simulation model and cooling system design method presented in this paper have excellent performance and meet the needs of engineering applications.