The Design And Realize Of The Loosely Coupled Transformer For The Contactless Charging System Of The Electric Vehicle

The issues of the environmental and energy become increasingly prominent, oneof the most effective solution that can solve those issues in the traffic field is todevelop the high efficiency and pollution-free pure electric vehicles. Its non-contactcharger has the advantage of no contact wear loss when uses frequently, more safetywhen uses in the humid environment, more convenient to use and the bright future ofactual application. The loosely coupled transformer is the main component in the non-contact power transfer and has a big influence on the whole system’s powertransmission characteristic, working air gap and the system shift performance.Therefore, the design and the realizable of the loosely coupled transformer hasimportant theoretical and practical significance. This article is based on the model ofthe loosely coupled transformer, do the research of four different basic compensationtopology characteristics, present a optimize method to design the loosely coupledtransformer and choose its parameters of the compensation circuit, then a new looselycoupled transformer is designed.Firstly, from the magnetic circuit theory, the loosely coupled transformer modelis obtained, then get the leakage inductance model. Analyze the four basiccompensation topology characteristics and combine with the requirement of thenon-contact charging electric vehicle, choose the SS as the system’s compensationtopology and then verify its characteristic.Secondly, according to the character that the loosely coupled transformer hasmany variables, put forward a optimize method of designing the turns ratio, system’sworking frequency. Based on the proposed method, a planar W type loosely coupledtransformer is built which can achieve a3kW non-contact power transfer and theexperimental results is consistent with the design requirement.Again, analyze the influence of the loosely coupled transformer’s transmissionpower and put forward the optimize goal of the transformer. Based on optimization ofthe planar W type loosely coupled transformer, the finally transformer is designedwhich is a planar W type loosely coupled transformer.Finally, the performance of the new loosely coupled transformer was tested, thetest results show that the new type of loosely coupled transformer performance meetthe design requirements.