Pulse width modulation technique with harmonic injection in the modulating wave and discontinuous frequency modulation for the carrier wave to reduce vibrations in asynchronous machines

Abstract

A new carrier-based pulse-width modulation (PWM) technique to control power inverters is presented in this study. To generate the output waveform, this technique compares a harmonic-injection modulating wave and a frequency-modulated triangular carrier wave. The instantaneous frequency for the carrier wave is adjusted according to a periodic function synchronised with the fundamental term of the modulating wave. The main motivation for using this technique compared to a classic PWM sinusoidal technique revolves around the reduction of total harmonic distortion, the reduction of the distortion factor and the shift of temporal harmonics to higher frequencies for any modulation frequency order. Experimental results show that it is possible to optimise the time harmonics generated to minimise vibrations produced by an induction motor when it is fed with a DC/AC converter controlled by the proposed control strategy. This is made possible by using a control parameter that modifies the instantaneous frequency of the carrier wave without modifying the number of pulses per period of the modulating wave, i.e. the mean value of the carrier wave frequency. The proposed technique is applied to an open loop-controlled inverter that operates an induction motor, helping to reduce the vibration levels produced. Nomenclature A M control parameter to adjust the maximum frequency of the carrier wave K truncated level of the function that controls the carrier wave frequency ω i instantaneous pulsation of a carrier wave ω m pulsation of the modulating wave M frequency modulation order M average value of the frequency modulation order IET Power Electron.

Improved harmonic injection pulse‐width modulation variable frequency triangular carrier scheme for multilevel inverters

“…Shifting the temporal harmonics to higher frequencies, the reduction of THD and DF with a fewer number of pulses per cycle are the main advantages of using this technique compared to the conventional POD‐PWM and VFTC‐PWM techniques. A high fundamental with the signal quality of the content of other harmonics are required to have high torque for electrical motor applications [18, 19]. According to Table 2, the proposed modulation strategy has the maximum value of in all 5‐, 7‐ and 9‐level inverter.…”

“…HI wave is employed as the reference wave, but only 3rd and 9th harmonic orders are injected into the reference wave and their magnitudes are not controllable. This technique has minimised the vibrations by an induction motor [18, 19]. After that, an improved HIPWM‐FMTC technique is proposed to overcome the drawbacks of calculation time and fewer number of controllable parameters.…”

Pulse-Width Modulation Technique With Harmonic Injection in the Modulating Wave and Discontinuous Frequency Modulation for the Carrier Wave for Multilevel Inverters: An Application to the Reduction of Acoustic Noise in Induction Motors

“…This reduces the number of commutations for each cycle of each switch, and can further increase the voltage and power of the electrical machine. To increase the voltage of the fundamental term, a sine wave signal with harmonic injection is used as the modulating signal [30], [31], [32]. The vibration modes when the motor is supplied with a balanced three-phase wave are variable, and the acoustic level emitted by the motor with these supplies is limited by the international standards.…”

Hybrid Carrier Frequency Modulation Based on Rotor Position to Reduce Sideband Vibro-Acoustics in PMSM Used by Electric Vehicles

“…In order to reduce the sideband components, some effective methods have been presented. The most representative method is called the harmonics spread spectra (HSS) technique, used in modulations such as periodic signal-based dithering modulation [14,15] and random pulse width modulation (RPWM) [16]. The periodic dithering modulation transfers the fixed carrier frequency to the determined periodic ways including the sawtooth, sinusoidal, and square [12,15].…”