輪轂電機(jī)驅(qū)動(dòng)電動(dòng)汽車機(jī)電耦合垂向動(dòng)力學(xué)特性

李天成 鄧兆祥 張河山 盧泮蘋 曾鵬飛

摘要：電動(dòng)車用輪轂電機(jī)受路面激勵(lì)和車重的雙重作用，定轉(zhuǎn)子相對(duì)偏心進(jìn)而產(chǎn)生不平衡磁拉力，其垂向分量與車輛懸架系統(tǒng)的垂向振動(dòng)相耦合，影響電動(dòng)汽車的平順性、舒適性等性能。針對(duì)這一機(jī)電耦合問(wèn)題，以一臺(tái)永磁式輪轂電機(jī)為研究對(duì)象，利用磁場(chǎng)疊加法獲得負(fù)載氣隙磁密分布，引入復(fù)數(shù)相對(duì)磁導(dǎo)和偏心磁導(dǎo)修正系數(shù)，建立考慮定子開(kāi)槽效應(yīng)的電機(jī)偏心磁場(chǎng)和不平衡磁拉力解析模型，并通過(guò)有限元仿真和樣機(jī)試驗(yàn)驗(yàn)證了解析模型的有效性。根據(jù)懸架系統(tǒng)的垂向振動(dòng)與電機(jī)偏心不平衡磁拉力的實(shí)時(shí)耦合關(guān)系，利用拉格朗日法求解車輛動(dòng)力學(xué)方程，建立1/4車身垂向耦合振動(dòng)模型。以輪轂電機(jī)定子垂向振動(dòng)加速度、車身垂向振動(dòng)加速度、懸架動(dòng)撓度和輪胎動(dòng)載荷為主要指標(biāo)，研究機(jī)電耦合效應(yīng)對(duì)車輛垂向動(dòng)力學(xué)特性的影響，揭示不平衡磁拉力輸出特性與車輛動(dòng)力學(xué)響應(yīng)之間的機(jī)電耦合機(jī)理。研究結(jié)果表明，機(jī)電耦合效應(yīng)使電動(dòng)汽車的平順性、操穩(wěn)性和安全性等性能總體下降。

關(guān)鍵詞：輪轂電機(jī)；磁隙偏心；機(jī)電耦合；不平衡磁拉力；垂向動(dòng)力學(xué)特性

中圖分類號(hào)：TM341????????? 文獻(xiàn)標(biāo)志碼：A????????? 文章編號(hào)：1000-582X（2024）01-069-15

Vertical dynamic characteristics of electromechanical coupling of in-wheel motor drive system for electric vehicle

LI Tiancheng1a，， DENG Zhaoxiang1a，1b， ZHANG Heshan2， LU Panping1a， ZENG Pengfei1a

（1a. College of Mechanical and Vehicle Engineering; 1b. The State Key Laboratory of Mechanical Transmissions， Chongqing University， Chongqing 400044， P. R. China; 2. College of Traffic & Transportation， Chongqing Jiaotong University， Chongqing 400074， P. R. China）

Abstract： Due to the double action of road excitation and vehicle weight， the stator and rotor of the in-wheel motor （IWM） for electric vehicles （EVs） are relatively eccentric， thus generating an unbalanced magnetic force （UMF）. When the vertical component of UMF is coupled with the vertical vibration of the suspension system of the vehicle， the ride comfort and other properties of EV are affected. To study this electromechanical coupling problem， by taking a permanent magnet IWM as the research object， the vertical dynamic characteristics of electromechanical coupling of an IWM drive system for electric vehicle were investigated. Firstly， the air gap flux density distribution of IWM under load was obtained by superposition method of magnetic field. By introducing complex relative permeance and correction coefficient of permeance when the motor was eccentric， analytical models of the eccentric magnetic fields of IWM and UMF were obtained with the stator slotting effect taken into account， and the validity of the analytical models was verified by finite element simulation and prototype test. Then， according to the real-time coupling relationship between the vertical vibration of the suspension system and the eccentric UMF of IWM， the dynamic equation of the vehicle was solved by using the Lagrangian method， and the vertical coupling vibration model of a quarter car body was established. Finally， taking the vertical vibration acceleration of the stator of IWM， the vertical vibration acceleration of the car body， the dynamic deflection of the suspension and the dynamic load of the tire as the main indexes， the effect of electromechanical coupling on the vertical dynamic characteristics of EV was studied， and the mechanism of electromechanical coupling between the output characteristics of UMF and dynamic response of EV was revealed. The results show that the electromechanical coupling effect impairs the ride stability， operation stability and safety of EV.

Keywords： in-wheel motor; magnetic gap eccentricity; electromechanical coupling; unbalanced magnetic force; vertical dynamic characteristics

輪轂電機(jī)驅(qū)動(dòng)系統(tǒng)具有高集成度、高功率密度等優(yōu)勢(shì)，能夠優(yōu)化車身結(jié)構(gòu)，提高車輛的空間利用率，但也會(huì)增加整車非簧質(zhì)量，使車輛平順性變差。馬英等[1]研究表明因驅(qū)動(dòng)電機(jī)布置于車輪內(nèi)部，簧載質(zhì)量和非簧載質(zhì)量之比減小，輪胎接地性能惡化。……