Dynamic Characteristics Analysis Of Power Split Device In HEV

Power split device (PSD) is the core component of hybrid electric vehicle (HEV),and its dynamic performance is related to transmission performance of parallel-serieshybrid electric vehicle. Prius are the most successful products of HEV currently,which are developed by Toyota. It has applied international patents for powercoupling device. In order to develop HEV quickly in our country, PSD withindependent intellectual property rights must be developed. Combining with thenational natural science foundation of China:“Design theory and method for powercoupler of hybrid electric vehicle in multi-field coupling (51075179)”, drivingmechanism, and contact analysis of transmission gear, and the test signal processingof bench test and dynamic performance of PSD are researched in this paper.(1) The working principle of traditional automotive differential is analyzed. Itpoints out that the THS of Toyota hybrid power system and PSD of differentialcoupling hybrid electric vehicle have similar functions. Through the Advisor, therotational speed and torque of PSD are simulated. The left and right half axis gearhave great speed difference, which always has been working.(2) Gear parameter of PSD is redesigned in this paper. Contact analysis oftransmission gear of PSD is studied by finite element analysis. The variable regularityof stress of PSD is discussed. At the same time, the law of stress dispersion anddistribution are pointed out.(3) The denoising method is researched based on wavelet threshold. Someproblems of the basis function, the number of decomposition layers, the determinationof threshold, and the determination of threshold function are discussed. A newthreshold function is proposed in this paper. The denoising performance is verified bythe square-wave signal and Leleccum signal effectively. The test signals, which areobtained by bench test of PSD, are processed by wavelet threshold.(4) A multi-joint rigid and flexible body dynamic simulation model of PSD isconstructed. Two conditions which include normal working and failure are simulationanalyses for PSD. It points out that the mesh impact of gear connected to the generator is smaller, and the mesh impact of gear connected to the motor is bigger. Atthe same time, rotate speed of planetary gear has huge swings under failure condition.This research provides reference for test data denoising and dynamicperformance of PSD, and has a certain engineering significance.