Improving the reliability of semiconductor converters for supplying electric drives of exhausters

Resumo

This article analyzes the existing methods of increasing reliability through multiple overstatement of the installed power of electric equipment according to the criterion of minimum total yearly costs. The proposed method of optimization of power circuits of semiconductor converters includes stages of choosing the configuration of power circuits on the basis of the limit of semiconductor switches and choosing the optimal number of phases and redundant units. The distinguishing characteristic of the method is the criterion used, namely, the probability of failure-free operation. This new method reduces the cost of installed power of a semiconductor converter compared to the known synthetic method on the level of total annual costs. It is shown that this method has some degree of flexibility; e.g., the development of the element base can be considered on the basis of the corresponding coefficients that depend on the operating temperature of power semiconductor valves. The proposed method can be successfully used in the design of semiconductor converters for supplying powerful electric drives, where, in the general case, the number of phases of a power circuit is not three. In this case, multiphase windings of an electric machine are connected according to a scheme with potential phase separation, which can be considered as an equivalent multiple redundancy system.