考虑数值噪声的热-电耦合系统分析

Thermal-electric coupling systems analysis of electronic cabinets with consideration of numerical noises

由于仿真计算中数值噪声的影响,优化的设计函数常常是不光滑或不连续的,为多学科之间的解耦和优化计算带来较大困难。为此,借鉴全局优化的相关理论,提出了考虑数值噪声的热-电耦合系统分析方法。在解耦方法上,根据"同时分析和设计"(SAND)思想,将解耦问题转化为一个优化问题,在学科层引入Kriging替代模型以便过滤数值噪声,并采用极大似然估计法确定新增样本点的位置,较大程度上减少了解耦分析所需的重分析次数,通过一个典型的热-电耦合算例验证了模型和方法的有效性。

One of the difficulties in multidisciplinary design optimization for electronic cabinets is that the design functions are often not smooth or even discontinuous due to numerical noises. In order to solve this problem, a global optimization strategy for multidisciplinary systems was developed. Firstly, the system analysis problem was transformed into an optimization problem according to the idea of SAND （ simultaneous analysis and design） . Kriging models were introduced as surrogate models for the output variables of each subsystem in order to filter the numerical noises. The initial Kriging models were built by using sparse sample points. The location of next samples was determined by an “infill sampling criterion^ which was derived by the maximum likelihood estimation. When the simulation tools exhibit large numerical noises, this method can greatly reduce the number of subsystem simulations needed in system analysis compared with other methods, such as the fixed point iteration method. Lastly, a typical thermal-electric coupling problem was taken as an example for demonstration of the effectiveness of the proposed method.