Optimization and Analysis of Transient Temperature Calculations for Frequency Converter in Changing Working Condition

In order to realize the application of digital twin technology, it is necessary to study the transient physical field of the research object. For frequency converters, their transient temperature is the focus of attention. Finite element transient simulation calculations generally require a lot of time. To address this problem, this study proposes a quick calculation method that combines fluid field simulation and heat transfer theoretical calculations. It first calculates the fluid field inside the frequency converter through simulation software and obtains the boundary conditions of the heat source. Then use the theory of heat transfer to establish a heat transfer model for the frequency converter, thereby obtaining the transient equation of the temperature change of the frequency converter with time. This calculation method does not require energy calculations, and can also avoid repeated iterative processes of transient calculations, which can significantly reduce the solution time. Finally, this paper verifies the accuracy of the calculation method through experiments. The accuracy of this method meets the engineering needs and can provide certain reference significance for the transient temperature analysis of electrical cabinets.