Reliability Evaluation And Optimization Design Of Power Converter

Power converters have been widely used in various fields, because of their excellentcomprehensive properties and energy efficiency. With the application of power converter,people pay more attention on converters’ reliability. However, a systematic and thoroughstudy on converters’ reliability has not been built yet, this result in a shortage of reliabilitygrowth. In this paper, reliability evaluation and optimal design of power converter is the maintarget. In the research of reliability evaluation, the data of life test is analysed, Mixed-Weibulldistribution model is constructed, then we can evaluate the reliability characteristics of powerconverter. In the research of reliability optimai design, based on the theory of complexnetwork, firstly set up the network model of power converter, then analysis the netwokcharacteristics to evaluate the difference of component importance, at last combined with theresult of component importance, a modified reliability allocation method is proposed, andsome measures for enhancing power converter reliability can be got.The main contents of this paper include:1. Considering power converters have several failure modes, we construct Mixed-Weibulldistribution model, Nonlinear Least Square theory is adopted to eatabish parameterestimation model, and Damped Newton Alogorithm is designed to solve the parameterestimation problem, finally a pratical example is used to verify the accurancy andprecision of this method.2. Referring to the theory of complex network, unweighted network model of powerconverter is constructed. And a method to evaluate component importance is proposed byusing importance evaluation matrix, in which we synthesize considering componentitself’s role in converter and adjacent components’ influence. Finally some praticalexamples are used to verify the validity of this method.3. Based on the result of component importance evaluation, an improved reliabilityallocation method is proposed, and a set of reliability optimal design method is putforward under the direction of reliability allocation, this method can guide the selectionof components’ rated electric stress. Finally, a experience of Buck converter verified thismethod is effective and feasible...