Common mode and differential mode characteristics of AC motor for EMC analysis

High‐frequency modelling of permanent magnet synchronous motor with star connection

“…The model calculated impedance fits quite well with the measured ones, which indicates that most of the CM effects in the motor can be well interpreted by the model proposed in this study. The model has largely enhanced the characteristics at the middle frequency range, especially in the frequency range of 100-500 kHz, compared with the models proposed in [10,11,13,14,21,22]. The resonance (point K in Fig.…”

“…With the merits of low noise, low inertia, high efficiency, and low maintenance cost, a permanent magnet synchronous motor (PMSM) has attracted growing international attention and has been widely applied in pulse width modulation (PWM) inverter-fed adjustable speed drive (ASD) system nowadays [1,2]. In such a PWM inverter-fed ASD system, the line-to-line voltage across motor terminals contains multiple high-frequency harmonic components, generated by high dv/dt or di/dt of the modern transistors, such as insulated gate bipolar transistor and metaloxide-semiconductor field-effect transistor [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Thus, the inverter is considered as the source of electromagnetic interference (EMI), and the parasitic capacitances and inductances existing in PMSM have provided propagation paths for conducted EMI emissions.…”

“…The high-frequency modelling of the motor is recommended in the earliest designing stage of the ASD system. Then, many high-frequency models for induction motors [10][11][12][13][14][15][16][17][18][19][20], brushless dc motor [21], and PMSM [22] have been proposed, respectively. Some simple models [15][16][17][18][19] are very helpful in estimating electric discharge machining current, overvoltage on motor terminals as well as bearing voltage/current, but these models are inadequate to analyse the conducted EMI emissions in the system because they cannot represent both CM and differential mode (DM) impedances of the motor very well.…”

“…The frequency range of the model only covers from 10 to 300 kHz. Meanwhile, some obvious deviations between the measured and model calculated CM and DM impedances, especially in the middle frequency range (10 kHz to 1 MHz), can be observed in the literature [10,11,13,14,21]. Another high-frequency model [20] for an induction motor applied in the ASD system is proposed based on the vector fitting (VF) method [23][24][25].…”

“…Some simple models [15–19] are very helpful in estimating electric discharge machining current, overvoltage on motor terminals as well as bearing voltage/current, but these models are inadequate to analyse the conducted EMI emissions in the system because they cannot represent both CM and differential mode (DM) impedances of the motor very well. The models presented in [10–14, 21, 22] have more complicated structures and can illustrate both CM and DM impedances of the motor correctly. However, the model proposed in [12] is also insufficient to analyse the conducted EMI emissions in the ASD system, due to the limited frequency range of the model.…”