複合動力電動車即時節能動力分配策略

Abstract

本研究提出一新型的複合動力電動車架構，採用50 kW直流無刷馬達搭配傳動齒輪箱，作為前輪間接驅動動力源；後輪則由兩顆盤型28 kW永磁同步馬達置於輪內，作為後輪直接驅動動力源。此複合動力架構，不但能提供車輛多自由度的控制性能，也能藉由操作各馬達的輸出力矩於高效率區間，達到提升整體行車效率與續航力之效果。本研究係以粒子群最佳化法，設計一套即時節能動力分配策略，此策略將於行車過程中，即時的分配各馬達動力，以持續的將各馬達操作於高效率區域，使行車時能在滿足駕駛者的加速性需求下，將行車效率最佳化。除此之外，為了提升策略的安全性與實用性，本研究整合即時節能動力分配策略與車身穩定控制，並以動力分配的方式避免輪胎打滑與轉向失控的問題。 最後，本研究除了使用軟體驗證所提出的策略之性能，還將即時節能動力分配策略建置於數位訊號處理器(digital signal processor, DSP)中，並以硬體即時模擬平台(hardware-in-the-loop, HIL)進行驗證。實驗結果顯示，即時節能動力分配策略確實能在不失駕駛者對車輛動態之需求與行車安全為前提下，在車輛進行直線以及轉向操作時，即時的分配動力以達到節能行車之效果。

This research proposes a new structure of power train for electric vehicle (EV), the power train of EV consists of three motors: an 50-kW indirectly-driven front traction motor with gearbox to reduces the motor speed by 6 times and two 28-kW directly-driven in-wheel motors installed inside both rear wheels. This power sources configuration not only provide the vehicle good performance for planar motion control, but also improve driving efficiency of vehicle by torque distribution of three motors. This research proposes a real-time optimization of torque distribution among three motors by particle swarm optimization (PSO). The torque distribution strategy will adjust torque command of motors by PSO that motors can be operated in high efficiency region, which the torque distribution algorithm can improves driving efficiency by minimizing each instantaneous power. In addition, in order to enhance the safety of vehicle driving, this research further develop the strategy by integrating electronic stability program (ESP), which composes by slip ratio controller (SRC) and direct yaw-moment controller (DYC). Finally, this study not only verifies the performance of the proposed strategy by using software simulation, but also builds the real-time energy economy torque distribution strategy in the digital signal processor (DSP), which certificated by the hardware-in-the-loop (HIL). Experimental results show that the torque distribution strategy can keep the driving safety by ESP and save energy on real-time when EV is driving on straight and curve roads.