Modeling and Suppression ofPWM Inverter's Adverse Effects

Analysis and Methodology for Determining the Parasitic Capacitances in VSI-fed IM Drives Based on PWM Technique

“…The procedures proposed for the development of this methodology are: a) determination of the equivalent circuit parameters of the three-phase induction motor in steady state and high frequency and [1,10,15,31] through typical laboratory test; b) establish settings of links between the PWM inverter and the motor for measurements of quantities of interest: common mode (V CM ) and shaft (V SHAFT ) voltages, leakage (I LEAKAGE ) and shaft (I SHAFT ) currents, developed by measuring circuit for this purpose [13,14]; c) calculate the values of the parasitic capacitances between stator and frame (C SF ), stator and rotor (C SR ), rotor and frame (C RF ) and bearings (C B ), using their characteristic equations [10,15]; d) using PSPICE [36] to simulate the system (three-phase induction motor fed by PWM inverter) with the high-frequency equivalent circuit in the same [6,16]; e) to obtain the waveforms characteristics of the EMI phenomena.…”

“…At high frequencies, the capacitive reactance among the various parts of the three-phase induction motor are shown in Figure 1, which illustrates the equivalent circuit of the threephase induction motor fed by PWM inverter [1,6,15]. The distributed parameters R, L, and C represent the high-frequency coupling between the windings of the stator and the rotor.…”

“…R W and L W represent the equivalent impedance of the driver through which circulates the bearing current and R g is the lead resistance connected between the frame and ground. Using the defined impedances shown by equations (1) through (4), one can obtain the high-frequency simplified circuit of the induction motor presented in Figure 2 [15]:…”

High frequency modeling of PMSM connected to long cable

“…the required signal and the differential mode noise take the same path which make it difficult to be deduced. In the literature, several researches efforts [1][2][3][4][5][6][7][8][9] have been carried out to model induction motor-inverterfeeding cables system with different degree of success, e.g. Erik [1] and Annette [2,3] provide an analysis based on reflected wave theory to show that the distributed LC of a cable and the PWM inverter switching action lead to motor over terminal voltage which, cause failure of the motor insulation.…”

“…In [4,5,6], differential and common mode modeling have been achieved to correct motor model at high frequency and to deal with shaft voltages and bearing currents due to common mode. In [7,8], high-frequency modeling for both long cable and induction motor have been achieved to deal with over voltages due wave reflection, in [9] a simulated results have been introduced to deal with suppression of inverter's adverse effect including EMI noise.…”