Topology and PWM Method Dependency of High Frequency Leakage Current Characteristics of Voltage Source Inverter Driven AC Motor Drives

2012-09-20
Cetin, N. Onur
Hava, Ahmet Masum
In PWM inverter based AC motor drives, high frequency common-mode voltage (CMV) causes high frequency common-mode current (CMC, motor leakage current). With its magnitude reaching ampere levels, the CMC can induce bearing failures, drive nuisance trips, EMC issues etc. The CMC is dependent on the inverter topology (two or three-level), PWM method (pulse pattern), and the filters if active/passive mitigation methods used. This paper investigates the CMV/CMC properties of the two and three-level VSIs [with and without common-mode inductor (CMI)] for various PWM methods. It shows the peak CMC is highly dependent on the PWM method and pulse sequence (in addition to dv/dt). The PWM methods pulse pattern and sequence analyses are supported by detailed experiments to illustrate that the reduced CMV PWM methods with proper pulse sequences yield low peak CMC and the inclusion of a CMI filter provides further suppression. Furthermore, the high frequency CMV/CMC spectra for various PWM methods are provided comparatively. It is shown that when the common-mode resonant frequency coincides with the dominant CMV frequency, the CMC can be amplified. As a result a comprehensive leakage current evaluation is provided in the paper. The information is useful for design and implementation of motor drive PWM algorithms and high frequency EMC filters in terms of CMV/CMC performance considering CMV/CMC reduction.

Suggestions

Common-Mode Voltage Reduction Pulsewidth Modulation Techniques for Three-Phase Grid-Connected Converters
Hou, Chung-Chuan; Shih, Chih-Chung; Cheng, Po-Tai; Hava, Ahmet Masum (2013-04-01)
This paper experimentally investigates the performance of three-phase voltage source pulsewidth modulation (PWM) converter, with the grid interfaced photovoltaic energy conversion system being the main application. In such applications the ground leakage current [common mode current (CMC)] should be much less than an ampere and this is difficult to obtain in transformerless (direct) connected systems. With the target being the reduction of the common mode voltage (CMV) and CMC, the converter performance is ...
Compatibility Issues Between the Filter and PWM Unit in Three-Phase AC Motor Drives Utilizing the Pure Sine Filter Configuration
Cetin, N. Onur; Hava, Ahmet Masum (2011-11-01)
Inserted between the inverter and the ac motor for the purpose of providing clean sinusoidal voltage at the motor terminals, the pure sine filter (PSF) involves common-mode and differential-mode suppression components. When using PSF in a motor drive and employing advanced pulsewidth modulation (PWM) techniques with discontinuous modulation waveforms, a large common-mode current may circulate through the inverter and the filter resulting in overcurrent stress in the inverter and significant acoustic noise i...
Performance Characteristics of the Reduced Common Mode Voltage Near State PWM Method
Un, E.; Hava, Ahmet Masum (2009-07-01)
The Near State PWM (NSPWM) method, which has low common mode voltage and low common mode current, is proposed for three-phase voltage source inverter drives. The method is described and its voltage linearity, output current ripple, DC bus current ripple, common mode voltage and output line-to-line pulse patterns are thoroughly studied and compared with classical PWM methods. The theory, simulation, and laboratory experiments illustrate that in the high modulation index operating range NSPWM has superior ove...
Performance analysis and comparison of reduced common mode voltage PWM and standard PWM techniques for three-phase voltage source inverters
Un, E; Hava, Ahmet Masum (2006-03-23)
This paper investigates the performance characteristics of the reduced common mode voltage (RCMV) PWM methods for three phase voltage source inverters and provides a comparison with the standard PWM methods. PWM methods are reviewed and their pulse patterns and common mode voltage patterns illustrated. The AC output current ripple, DC link input current ripple, and output voltage linearity characteristics of each modulation method are thoroughly investigated by analytical methods and simulations. The analys...
Performance characteristics of the reduced common mode voltage Near State PWM method
Un, Emre; Hava, Ahmet Masum (2007-09-05)
The Near State PWM (NSPWM) method, which has low common mode voltage/current is proposed for three-phase voltage source inverter drives. The method is described and its voltage linearity, output current ripple, DC bus current ripple, common mode voltage and output line-to-line pulse patterns are thoroughly studied and compared with classical PWM methods. The theory, simulation, and laboratory experiments illustrate that NSPWM has low common mode voltage, results in less common mode current, has low switchin...
Citation Formats
N. O. Cetin and A. M. Hava, “Topology and PWM Method Dependency of High Frequency Leakage Current Characteristics of Voltage Source Inverter Driven AC Motor Drives,” 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53521.