Improved selective harmonic elimination for reducing torque harmonics of induction motors in wide DC bus voltage variations

Conventionally, Selective Harmonic Elimination (SHE) method in 2-level inverters, finds best switching angles to reach first voltage harmonic to reference level and eliminate other harmonics, simultaneously. Considering Induction Motor (IM) as the inverter load, and wide DC bus voltage variations, the inverter must operate in both over-modulation and linear modulation region. Main objective of the modified SHE is to reduce harmonic torques through finding the best switching angles. In this paper, optimization is based on optimizing phasor equations in which harmonic torques are calculated. The procedure of this method is that, first, the ratio of the same torque harmonics is estimated, secondly, by using that estimation, the ratio of voltage harmonics that generates homogeneous torques is calculated. For the estimation and the calculation of the ratios motor parameter, mechanical speed of the rotor, the applied frequency, and the concept of slip are used. The advantage of this approach is highlighted when mechanical load and DC bus voltage variations are taken into consideration. Simulation results are presented under a wide range of working conditions in an induction motor to demonstrate the effectiveness of the proposed method.

[1]  Joachim Holtz,et al.  Low switching frequency and high dynamic pulsewidth modulation based on field-orientation for high-power inverter drive , 1992 .

[2]  Hiralal M. Suryawanshi,et al.  Closed-loop hybrid direct torque control for medium voltage induction motor drive for performance improvement , 2014 .

[3]  Shailendra Jain,et al.  Torque ripple reduction technique with improved flux response for a direct torque control induction motor drive , 2013 .

[4]  G. Narayanan,et al.  Reduction of Torque Ripple in Induction Motor Drives Using an Advanced Hybrid PWM Technique , 2010, IEEE Transactions on Industrial Electronics.

[5]  Eugene A. Klingshirn,et al.  Polyphase Induction Motor Performance and Losses on Nonsinusoidal Voltage Sources , 1968 .

[6]  V. S. S. Pavan Kumar Hari,et al.  Space-Vector-Based Hybrid PWM Technique to Reduce Peak-to-Peak Torque Ripple in Induction Motor Drives , 2016 .

[7]  Paul C. Krause,et al.  Method of Multiple Reference Frames Applied to the Analysis of Symmetrical Induction Machinery , 1968 .

[8]  M. Sanada,et al.  A PWM strategy for reducing torque-ripple in inverter-fed induction motor , 1992, Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting.

[9]  Tobias Geyer,et al.  Analytical expression of pulsating torque harmonics due to PWM drives , 2013, 2013 IEEE Energy Conversion Congress and Exposition.

[10]  Stuart D. T. Robertson,et al.  Torque Pulsations in Induction Motors with Inverter Drives , 1971 .

[11]  G. Narayanan,et al.  Evaluation and Minimization of Low-Order Harmonic Torque in Low-Switching-Frequency Inverter-Fed Induction Motor Drives , 2014, IEEE Transactions on Industry Applications.

[12]  Bimal K. Bose,et al.  Power Electronics and Ac Drives , 1986 .

[13]  Mohan V. Aware,et al.  Torque ripple reduction in five-phase direct torque controlled induction motor , 2014, 2014 IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES).

[14]  Weizhong Fei,et al.  Analytical investigation of sideband torque ripple in induction machine drive with SPWM and SVPWM techniques , 2014, 2014 17th International Conference on Electrical Machines and Systems (ICEMS).

[15]  Giuseppe S. Buja,et al.  Optimal Pulsewidth Modulation for Feeding AC Motors , 1977, IEEE Transactions on Industry Applications.

[16]  G. C. Jainy.  The Effect of Voltage Waveshape on the Performance of a 3-Phase Induction Motor , 1964 .

[17]  Andreas Steimel.  Direct self-control and synchronous pulse techniques for high-power traction inverters in comparison , 2004, IEEE Transactions on Industrial Electronics.