Abstract:This paper applies frequency domain parasitic capacitance method to calculate the Hertz bearing current density of variable frequency driven motor. The parasitic capacitances of the motor system are studied as the research object in this method. A 3kW variable frequency driven motor is studied as the research object in this paper and impedance characteristic of the parasitic capacitance is confirmed by the method of analysis. The impedance characteristic of the parasitic capacitance is also measured to by impedance analyzer check calculation results. According to variable frequency driven motor system coupling capacitance model the bearing current linear differential equation is formulated and solved by the linear expansion general approach. Consequently the electric discharge current is confirmed. The experiment method of measuring the bearing current is improved, and the experimental platform is built. The calculated result of the bearing current is conforming to the measurement value. This kind of bearing current density calculation method provides a theoretical basis for the quantitative evaluation of bearing damage.
王禹,白保东,刘威峰,陈德志. 频域寄生电容法变频电机Hertz轴承电流密度计算[J]. 电工技术学报, 2015, 30(2): 189-195.
Wang Yu,Bai Baodong,Liu Weifeng,Chen Dezhi. Hertz Bearing Current Density Calculation of Variable Frequency Driven Motors by Frequency Domain Parasitic Capacitance Method. Transactions of China Electrotechnical Society, 2015, 30(2): 189-195.
[1] 钟玉林, 赵争鸣. 改进式SHEPWM对三电平变频器系统的共模电压和轴电压的抑制作用[J]. 电工技术学报, 2009, 24(6): 48-55. Zhong Yulin, Zhao Zhengming. Common mode voltage and shaft voltage suppression on a three-level NPC inverter system applying improved SHEPWM[J]. Transactions of China Electrotechnical Society, 2009, 24(6): 48-55. [2] 孟进, 马伟明, 张磊, 等. 考虑PWM调制策略的逆变器共模和差模干扰源模型[J]. 电工技术学报, 2007, 22(12): 92-97. Meng Jin, Ma Weiming, Zhang Lei,et al. DM and CM EMI sources modeling for inverters considering the PWM strategies[J]. Transactions of China Electrotech- nical Society, 2007, 22(12): 92-97. [3] 高强, 徐殿国. PWM逆变器输出端共模与差模电压d v /d t 滤波器设计[J]. 电工技术学报, 2007, 22(1): 79-84. Gao Qiang, Xu Dianguo. Design of common-mode and differential-mode voltage dv/dt filter at PWM inverter output terminals[J]. Transactions of China Electrotechnical Society, 2007, 22(1): 79-84. [4] 袁佳歆, 潘建兵, 饶斌斌, 等. 三相逆变器的最小共模电压PWM控制[J]. 电工技术学报, 2012, 27(8): 42-48. Yuan Jiaxin, Pan Jianbing, Rao Binbin, et al. Research on minimum common-mode voltage PWM control strategy for three-phase inverters[J]. Transactions of China Electrotechnical Society, 2012, 27(8): 42-48. [5] Chen S, Lipo T A, Fitzgerald D. Modeling of motor bearing currents in PWM inverter drives[J]. IEEE Transactions on Industry Applications, 1995, 32(6): 388-393. [6] Muetze A, Binder A. Practical rules for assessment of inverter-induced bearing currents in inverter-fed AC motors up to 500kW[J]. IEEE Transactions on Industrial Electronics, 2007, 54(3): 1614-1622. [7] Busse D F, Erdman J M, Kerkman R J. The effects of PWM voltage source inverters on the mechanical performance of rolling bearings[J]. IEEE Transactions on Industry Applications, 1997, 33(2): 250-259. [8] Erdman J M, Kerkman R J, Schlegel D W. Effect of PWM inverters on AC motor bearing currents and shaft voltages[J]. IEEE Transactions on Industry Applications, 1996, 32(2): 250-259. [9] Busse D F, Erdman J M, Kerkman R J. Bearing currents and their relationship to PWM drive[J]. IEEE Transactions on Power Electronics, l997, 12(2): 243-252. [10] Wang S. Development of theoretical contact width formulas and a numerical model for curved rough surfaces[J]. Journal of Tribology Transactions of the ASME, 2004, 129(4): 735-742. [11] Marc Carpino, Gita Talmage. Minimum film thickness in a gas foil journal bearing with an unbalanced rotor[J]. Tribology Transactions, 2010, 53(3): 433-439. [12] Kataoka Takumi, Kikuchi Takashi, Ashihara, et al. Measurement of oil film thickness in the main bearings of an operating engine using thin-film electrode[C]. SAE Technical Papers, 2011. [13] Zhang Jie, Drinkwater B W, Dwyer Joyce R S. Acoustic measurement of lubricant-film thickness distribution in ball bearings[J]. Journal of the Acoustical Society of America, 2006, 119(2): 63-71. [14] Muetze A, Binder A. Calculation of motor capacitances for prediction of the voltage across the bearings in machines of inverter-based drive systems[J]. IEEE Transactions on Industry Applications, 2007, 43(3): 665-672.