Acoustic Signature Analysis and Sound Source Localization for a Three-Phase AC Induction Motor

As part of the recent electrification of the transportation industry, internal combustion engines are being coupled with or replaced by electric motors. This movement towards an electrified drivetrain poses new noise, vibration, and harshness (NVH) challenges related to electric motors. In this paper, the acoustic signature of an electric motor was analyzed to obtain a better understanding of the sound generated by these motors. This work provides an insight into an acoustic measurement technique that can be used to identify certain frequency bands that significantly contribute to the perceived sound. In the first part, the structural response of the motor was correlated with its acoustic spectra. Furthermore, data from acoustic and structural measurements were used to analyze the order content of the signal and identify critical contributors to the overall perceived sound. The differences between data captured by microphones in different positions around the motor helped to localize components of the overall sound. The results provide some discussion about techniques to decrease the overall sound. The technique described in this paper can be extended to fan-cooled motors that are used in vehicles such as golf carts or as auxiliary motors in electric/hybrid vehicles, as well as across a wide range of industrial applications.

Characteristics of the Polishing Effects for the Stainless Tubes in Magnetic Finishing with Gel Abrasive

Magnetic abrasive finishing (MAF) is a fast, high efficiency and high-precision polishing method on the surface machining of the metals. Furthermore, MAF also can be utilized to polish the stainless tubes in industrial applications; however, stainless tubes are often a non-magnetic material that makes it difficult for the magnetic field line to penetrate into the stainless tubes, thus reducing the magnetic forces in the inner tubes polishing. That is why stainless tubes are not easy to finish using traditional MAF. Therefore, magnetic finishing with gel abrasive (MFGA) applies gels mixed with steel grit and abrasives that were developed to improve the polishing efficiency and surface uniformity of the steel elements. In this study, a guar gum or silicone gel mixed with steel grit and silicon carbides are used as the magnetic abrasive gel to polish the stainless inner tubes. A DC motor was used to control the rotation speed of the chuck and an AC induction motor connected with an eccentric cam to produce the reciprocating motion of the workpiece were utilized to finish the inner surface of stainless tubes in the polishing process. The parameters of abrasive concentration, abrasive particle sizes, rotation speeds of motor and electric currents were used to investigate the surface roughness and the removal of materials from the stainless tubes. The experimental results showed that since guar gum had better fluidity than the silicone gel did, guar gum created excellent polishing efficiency in MFGA. Furthermore, the surface roughness of the stainless tube decreased from 0.646 μm Ra to below 0.056 μm Ra after processing for 30 min with the parameters of current 3A, gel abrasive with guar gum, rotational speed 1300 rpm and vibration frequency 4 Hz.

SPWM Fed Induction Motor Drive Performance Using SIMULINK

In the former times, IC engines were used for transportation by most of the vehicles. But due to the depletion of fossil fuels day to day, the world is moving towards the Electric Vehicles (EVs) to overcome this problem. Electric Vehicles have higher efficiency and weight/power ratio. In general, DC motors were used in electric vehicles. The DC motors could not meet the requirements of customer needs because of its low speed range. In the recent studies, an AC Induction motor has several advantages over DC motors because of its robustness, high speed range, and efficiency and weight/power ratio. This paper presents the performance analysis of AC Induction motor when fed with the Single-Phase Inverter. The gate pulses are given by using Sinusoidal Pulse Width Modulation (SPWM) technique. The results are then compared with the performance of DC motor using MATLAB/SIMULINK.

Experimental Investigations of Instantaneous Angular Speeds and Torsional Vibration in an AC Motor Driven Rotor System Involving a Variable Frequency Drive

Torsional vibration of a complex electro-mechanical system consisting of a VFD controller and AC induction motor is investigated in this thesis to study the dynamical behavior of a rather complex motor drive, used to power a DC generator and a set of heat-generation resistors for achieving various levels of nominal loads over a wide range of nominal frequencies/speeds. Two magnetic encoders are placed at two locations to record the arrival times of two arrays of teeth in connection with a data acquisition system. Through a Matlab-coded algorithm, the instantaneous angular speeds and their harmonic compositions up to 16th order of the mean motor speed can be accurately discerned. The model and the algorithms developed in this thesis can be used in a variety of machines and testing systems powered by induction motors and regulated by variable-frequency-drive controllers for design, condition monitoring and identification of sources of noise and disastrous vibration.

Experimental Investigations of Instantaneous Angular Speeds and Torsional Vibration in an AC Motor Driven Rotor System Involving a Variable Frequency Drive

Torsional vibration of a complex electro-mechanical system consisting of a VFD controller and AC induction motor is investigated in this thesis to study the dynamical behavior of a rather complex motor drive, used to power a DC generator and a set of heat-generation resistors for achieving various levels of nominal loads over a wide range of nominal frequencies/speeds. Two magnetic encoders are placed at two locations to record the arrival times of two arrays of teeth in connection with a data acquisition system. Through a Matlab-coded algorithm, the instantaneous angular speeds and their harmonic compositions up to 16th order of the mean motor speed can be accurately discerned. The model and the algorithms developed in this thesis can be used in a variety of machines and testing systems powered by induction motors and regulated by variable-frequency-drive controllers for design, condition monitoring and identification of sources of noise and disastrous vibration.

Integrated Charger-Inverter for High-Performance Electric Motorcycles

A high-performance electric motorcycle (HPEM) integrated charger-inverter (ICI) with an induction motor (IM) is proposed in this article. Typical components are shared in drive and charge modes, resulting in savings of weight, volume, and cost. A two-stage ICI for AC induction motor powertrain with power factor correction (PFC) and battery charger functions is considered. Despite high voltage ripple on the DC link, a high bandwidth nonlinear controller can reject such a drawback and adequately provide a constant current or constant voltage charging process. The simulation results of 7 kW ICI are provided to validate the effectiveness and feasibility of the proposed system. Finite element analysis (FEA) determines the torque and losses of IM in charging mode.

Experimental and Theoretical Performance Analysis of Emission and Combustion Characteristics of Diesel Engine using Bio Diesel as an Alternate Fuel

In this study the biodiesel derived from different vegetable oil esters (VOE) including Jatropha and Karanja is compared with diesel. The efficiency, emission and combustion properties of different VOE in single cylinder compression ignition engine were compared with Diesel. The main objective of our study is the theoretical and experimental comparison of the efficiency, emission and combustion properties of biodiesel using Jatropha and Karanja esters with diesel. Vegetable oil from Jatropha and Mahua was transesterified and used in a turbocharged engine water-cooled single-cylinder Diesel Engine attached to an ac induction motor with a current of 0 to 5kw. Brake thermal efficiency is decreased by around 1.4 percent for Jatropha, 2.0 percent for Karanja compared to Diesel. Brake specific fuel consumption improved by 0.2 percent for Jatropha and 3.4 percent for Karanja compared to Diesel.