电缆温度的暂态计算对其传输容量的合理分配及安全预警具有重要意义。然而在实际计算直埋电缆的温度时,存在电缆绝缘材料及周围土壤的热参数(密度、比热容、导热率)不易获取,或绝缘材料的热参数因老化而改变等问题,使得数值方法和传统...电缆温度的暂态计算对其传输容量的合理分配及安全预警具有重要意义。然而在实际计算直埋电缆的温度时,存在电缆绝缘材料及周围土壤的热参数(密度、比热容、导热率)不易获取,或绝缘材料的热参数因老化而改变等问题,使得数值方法和传统热路法难以实现对电缆温度的精确计算。当电缆状况和敷设环境已知时,在传统电缆热路模型的基础上,提出了一种通过信赖域算法后,再根据实测量温度来拟合改进的热路模型参数的方法,并得出电缆的缆芯和表面温度简化计算式,避免了绝缘层和敷设环境热参数难以获取的问题,减小了电缆温度的计算量。最后使用110 k V XLPE电缆开展直埋电缆的温升实验,将实测温度与计算值对比,仅存在较小的误差,证明了热路参数拟合和温度简化计算式的准确性。展开更多
Hermetically Sealed Electromagnetic Relay(HSER), used in aviation and aerospace,demands high reliability due to its critical applications. Given its complex operating conditions, efficient thermal analysis is essentia...Hermetically Sealed Electromagnetic Relay(HSER), used in aviation and aerospace,demands high reliability due to its critical applications. Given its complex operating conditions, efficient thermal analysis is essential for optimizing reliability. The commonly used Finite Element Method(FEM) is often time-consuming and may not be efficient or adaptable for complex multi-dimensional system calculations and design processes. This paper introduces an analysis method for thermal networks based on matrix perspective technology, encompassing matrix transformation, backpropagation of the heat path model, temperature rise calculation, solution comparison, and product implementation. Using the similarity theory of heat circuits, a basic thermal unit is established. Based on the fundamental connection between key components, a thermal network for a typical HSER is designed. An experimental system is set up, and the thermal network model's accuracy is confirmed using test data. Employing the topology analysis method, the topology of the thermal network is analyzed under both coil-energized and de-energized states. Potential thermal paths are identified, leading to optimized solutions for the HSER. Utilizing these solutions, the thermal path matrix topology model is backpropagated to the thermal path for temperature rise calculations. When compared to prototype HSER test data, the efficiency and accuracy of this matrix topology-based analysis method are confirmed.展开更多
由于芯片集成度的提高,改善电路性能的同时也导致功率密度增加。为了防止芯片过热,保证芯片可靠、稳定的工作,设计了一款基于电流比较的新型过温保护电路。电路通过产生与绝对温度(正/负温度系数PTAT/CTAT)相关的电流并进行电流比较,输...由于芯片集成度的提高,改善电路性能的同时也导致功率密度增加。为了防止芯片过热,保证芯片可靠、稳定的工作,设计了一款基于电流比较的新型过温保护电路。电路通过产生与绝对温度(正/负温度系数PTAT/CTAT)相关的电流并进行电流比较,输出包含温度信息的逻辑控制信号,实现对芯片工作状态的控制。对电路的工作原理进行了详细的分析和推导,并给出了电路中核心器件的参数设置。基于UMC 0.6μm Bi CMOS工艺进行了流片并对电路进行了测量,热关断、开启温度分别为125℃和114℃,具有11℃的温度滞回量;转换速率26.2 V/℃,具有高灵敏度、高精度的特点;当供电电压发生变化时,电路性能稳定,具有较好的应用前景。展开更多
气体绝缘开关设备(GIS)电缆终端的轴向传热特性对电缆资产的可靠性与利用率均有重要意义。文中建立GIS电缆终端等效热路模型,理论分析其传热特性与载流热点,通过搭建110 k V GIS电缆终端大电流实验平台,激励800~1 200 A稳态负荷电流,量...气体绝缘开关设备(GIS)电缆终端的轴向传热特性对电缆资产的可靠性与利用率均有重要意义。文中建立GIS电缆终端等效热路模型,理论分析其传热特性与载流热点,通过搭建110 k V GIS电缆终端大电流实验平台,激励800~1 200 A稳态负荷电流,量化分析其轴向传热特性与影响范围。结果显示,GIS电缆终端轴向传热程度与载荷大小正相关,当载荷为1 200 A时,至高点温度为93.0℃,最大轴向温差可达15.4℃,已超过电缆线路的额定载流量。分析表明,GIS电缆终端轴向传热明显,其影响范围为尾管后1 m左右,顶推弹簧截面处的导体为温度至高点,环境温度对GIS电缆终端与电缆本体影响权重等同并呈线性规律。研究结果可为电力调度及运行维护部门评估电缆线路载流量提供参考。展开更多
基金国家自然科学基金资助项目(51577106)supported by The National Natural Science Foundation of China(No.51207081)
文摘电缆温度的暂态计算对其传输容量的合理分配及安全预警具有重要意义。然而在实际计算直埋电缆的温度时,存在电缆绝缘材料及周围土壤的热参数(密度、比热容、导热率)不易获取,或绝缘材料的热参数因老化而改变等问题,使得数值方法和传统热路法难以实现对电缆温度的精确计算。当电缆状况和敷设环境已知时,在传统电缆热路模型的基础上,提出了一种通过信赖域算法后,再根据实测量温度来拟合改进的热路模型参数的方法,并得出电缆的缆芯和表面温度简化计算式,避免了绝缘层和敷设环境热参数难以获取的问题,减小了电缆温度的计算量。最后使用110 k V XLPE电缆开展直埋电缆的温升实验,将实测温度与计算值对比,仅存在较小的误差,证明了热路参数拟合和温度简化计算式的准确性。
基金supported by the National Natural Science Foundation of China (No. 52177134)。
文摘Hermetically Sealed Electromagnetic Relay(HSER), used in aviation and aerospace,demands high reliability due to its critical applications. Given its complex operating conditions, efficient thermal analysis is essential for optimizing reliability. The commonly used Finite Element Method(FEM) is often time-consuming and may not be efficient or adaptable for complex multi-dimensional system calculations and design processes. This paper introduces an analysis method for thermal networks based on matrix perspective technology, encompassing matrix transformation, backpropagation of the heat path model, temperature rise calculation, solution comparison, and product implementation. Using the similarity theory of heat circuits, a basic thermal unit is established. Based on the fundamental connection between key components, a thermal network for a typical HSER is designed. An experimental system is set up, and the thermal network model's accuracy is confirmed using test data. Employing the topology analysis method, the topology of the thermal network is analyzed under both coil-energized and de-energized states. Potential thermal paths are identified, leading to optimized solutions for the HSER. Utilizing these solutions, the thermal path matrix topology model is backpropagated to the thermal path for temperature rise calculations. When compared to prototype HSER test data, the efficiency and accuracy of this matrix topology-based analysis method are confirmed.
文摘由于芯片集成度的提高,改善电路性能的同时也导致功率密度增加。为了防止芯片过热,保证芯片可靠、稳定的工作,设计了一款基于电流比较的新型过温保护电路。电路通过产生与绝对温度(正/负温度系数PTAT/CTAT)相关的电流并进行电流比较,输出包含温度信息的逻辑控制信号,实现对芯片工作状态的控制。对电路的工作原理进行了详细的分析和推导,并给出了电路中核心器件的参数设置。基于UMC 0.6μm Bi CMOS工艺进行了流片并对电路进行了测量,热关断、开启温度分别为125℃和114℃,具有11℃的温度滞回量;转换速率26.2 V/℃,具有高灵敏度、高精度的特点;当供电电压发生变化时,电路性能稳定,具有较好的应用前景。
文摘气体绝缘开关设备(GIS)电缆终端的轴向传热特性对电缆资产的可靠性与利用率均有重要意义。文中建立GIS电缆终端等效热路模型,理论分析其传热特性与载流热点,通过搭建110 k V GIS电缆终端大电流实验平台,激励800~1 200 A稳态负荷电流,量化分析其轴向传热特性与影响范围。结果显示,GIS电缆终端轴向传热程度与载荷大小正相关,当载荷为1 200 A时,至高点温度为93.0℃,最大轴向温差可达15.4℃,已超过电缆线路的额定载流量。分析表明,GIS电缆终端轴向传热明显,其影响范围为尾管后1 m左右,顶推弹簧截面处的导体为温度至高点,环境温度对GIS电缆终端与电缆本体影响权重等同并呈线性规律。研究结果可为电力调度及运行维护部门评估电缆线路载流量提供参考。
