An objective for power electronics engineers: optimize the life-time cost

In the past, power electronic engineers normally tried to optimize the manufacturing costs of a product. It is demonstrated that it is more important to optimize life-time cost than manufacturing cost. For power electronic systems the most important after sales costs are the costs for loss energy. An estimation of the cost of loss energy is done. For the examples of a switch mode power supply and an electric locomotive it is shown, that the costs are significant high compared to the price of the product itself. Some approaches to increase efficiency are presented. An important issue is the selection of an effective system structure. Other possibilities to reduce losses are `oversizing´, optimized switching frequency, optimized snubbers, intelligent modulation techniques, multi-level-inverters, low-slip-machines, conductors with reduced skin-effect related losses or avoiding noload