Abstract
To increase the power density of the inverters for power industry, the new air cooling system of high power inverters were developed. Parallel air flow inverters carrying 18 differential units were introduced without unit fan because of easier maintenance and lower cost. Realizing the systems for inverter design, we proposed a useful and epoch-making analysis method named “Air flow equivalent circuits analysis combined with finite element method”. The inverters were divided into a small block and analyzed individually, and their results of the resistances were built into equivalent circuits. The proposed analysis method enables to calculate the wind velocities and pressure drops of the whole inverter panels, which unable to be solved in case of FEM analysis with the numerous mesh for the whole ones. Air flow resistances of merging ducts including the smaller parts could be evaluated in the methods. Therefore, we contribute to decrease the cooling design time within 1 second at the process of mass-produced design.