Permanent-magnet synchronous motors (PMSMs) have been widely used as the driving core in electric vehicles due to the high power/torque density and high efficiency. Recent years have witnessed a great effort on the vibration and noise of PMSMs in order to ensure the driving comfort. In this paper, the state of the art and recent progress of the electromagnetic vibration and noise of PMSMs for electric vehicles are presented, with emphasis on the induced mechanism, prediction method, suppression method, and sound quality. The future trends faced are also described.

Electromagnetic Vibration and Noise of the Permanent-Magnet Synchronous Motors for Electric Vehicles: An Overview

Spread-spectrum (SS)-based pulsewidth modulation (PWM) techniques play an important role when tackling the electromagnetic interference (EMI) problem in the switch-mode power supply (SMPS) domain. They achieve the best EMI noise reduction and emerge as a promising and very effective solution to comply with electromagnetic standards. The current work provides an insight into the SS techniques: its history, its types, and mainly its ability to mitigate the EMI problem in the SMPS domain. Moreover, it gives a short review of the different SS-based PWM techniques going from the most basic and simple, i.e., the periodic modulation, to the most developed and complex, i.e., the random and chaotic modulations. Besides, a short review of the different implementation methods was addressed and they were categorized into analog and digital implementation techniques where its pros and cons were provided. Finally, a new fast digital implementation method based on a dsPIC33F microcontroller is presented. Its effectiveness was proved and its advantages over the reviewed implementation techniques were recognized. It reached a 20 dBuV EMI level reduction when the digital chaotic and periodic profiles were embedded into a boost converter prototype.

A Review of Spread-Spectrum-Based PWM Techniques—A Novel Fast Digital Implementation

This paper proposed a novel hybrid random pulsewidth modulation (HRPWM) technique based on the modified space vector PWM for three-phase voltage source inverters to eliminate the PWM acoustic noise. Due to PWM technique and switching losses considerations, ear-piercing high-frequency noise from motor is common. The proposed HRPWM technique is able to remove the high-frequency unpleasant acoustic noise more effectively than the conventional RPWM with lower switching losses and shorter random frequency range. In addition, the PWM harmonics in phase voltage and phase current are reduced significantly. The HRPWM method is simple to implement and does not employ additional circuits in drive system. Finally, the effectiveness of the proposed approach has been confirmed by detailed experimental results.

Hybrid RPWM Technique Based on Modified SVPWM to Reduce the PWM Acoustic Noise

Since electrical machines are the largest consumer of electricity worldwide, their fault diagnostic at the incipient stage and condition monitoring is essential for better reliability, economy, and safety of operation. Out of several condition monitoring techniques, motor current signature analysis is gaining heightened popularity because of its non-invasive nature, the least number of sensors required and versatility of compatible algorithms. In this study, the best characteristics of infinite impulse response (IIR) filter are exploited to observe the broken rotor bar (BRB) frequencies with good legibility in current and voltage spectrum of the grid and inverter-fed motor, respectively. The causes of various harmonics in the stator current spectrum are first investigated for better understanding. The results are taken based on simulation and measurements taken from the laboratory setup. It is observed that a better tuning of IIR filters can make diagnostic algorithms capable of detecting the frequencies of interest by effectively attenuating the fundamental component and reducing its spectral leakage. Moreover, in case of direct torque control-based industrial inverter-fed motors, the current cannot be a good candidate for fault diagnostics rather the phase voltage can be effectively used for the detection of BRBs.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-epa.2019.0350

Broken rotor bar fault detection of the grid and inverter-fed induction motor by effective attenuation of the fundamental component

The permanent magnet synchronous motors (PMSMs) with space vector pulsewidth modulation (SVPWM) technique will inevitably introduce sideband current harmonic components around the carrier frequency. The armature reaction field caused by the sideband current interacts with the permanent magnet field, generating sideband electromagnetic force and resulting in high-frequency noise. This paper provides a comparative study of the sideband electromagnetic force in internal and external rotor PMSMs with SVPWM technique. First, the analytical model of the electromagnetic force in internal and external rotor PMSMs is established based on the Maxwell tensor method. The source, spatial order, and frequency of the electromagnetic force is obtained. Then, the spatial and temporal characteristics of the sideband force in internal and external rotor PMSMs with different pole and slot combinations are derived and investigated. The results show that the frequency characteristics of the zeroth order sideband force in internal and external rotor PMSMs introduced by SVPWM are identical. However, the frequency characteristics demonstrate significant differences for the nonzeroth order sideband force. Finally, the theoretical analysis is validated through the finite element and experimental results, respectively. This study is benefit for the source identification and reduction of high-frequency acoustic noise for PMSMs.

Comparative Study of Sideband Electromagnetic Force in Internal and External Rotor PMSMs With SVPWM Technique

One of the problems of the pulse-width-modulation (PWM)-controlled ac machines is the acoustic noise that could become unacceptable when used in sensitive environments. Random PWM (RPWM) in industrial and commercial adjustable-speed drives (ASD) results in the partial transfer of power from the discrete spectrum (narrowband noise) of the output voltage to the continuous spectrum (wideband noise), with advantageous effects on reducing the acoustic noise in the motor drive system. In this paper, the theoretical power spectrum analysis as the basis for RPWM is presented. Five state-of-the-art RPWM strategies, their voltage, current, and acoustic noise spectra characteristics are quantitatively evaluated. The PWM schemes and theoretical analysis are validated through a 2.2-kW 380-V 50-Hz ASD induction machine experimental setup. The results provide valuable data for practicing engineering community to choose the best option in real-world applications.

Performance Characterization of Random Pulse Width Modulation Algorithms in Industrial and Commercial Adjustable-Speed Drives

One of the problems of the pulse width modulation (PWM) controlled AC machines is the acoustic noise that could become unacceptable when used in sensitive environments. Random PWM (RPWM) in industrial and commercial adjustable speed drives (ASD) results in the partial transfer of power from the discrete spectrum (narrowband noise) of the output voltage to the continuous spectrum (wideband noise), with advantageous effects on reducing acoustic noise in the motor drive system. In this paper, the theoretical power spectrum analysis as the basis for RPWM is presented. Five state-of-the-art RPWM strategies, their voltage, current and acoustic noise spectra characteristics are quantitatively evaluated. The PWM schemes and theoretical analysis are validated through a 2.2kW, 380V, 50Hz ASD, induction machine (IM) experimental setup. The results provide valuable data for practicing engineering community to choose the best option in real world applications.

Guangtong Shen

Papers

Performance Characterization of Random Pulse Width Modulation Algorithms in Industrial and Commercial Adjustable-Speed Drives

Performance characterization of random pulse width modulation algorithms in industrial and commercial adjustable speed drives