Motor Power Rating Research Articles

FEA-based pole arc optimization and sensitivity analysis of 8/6 SRM for EV application

The optimization of the pole arcs and sensitivity analysis of a 4-phase 8/6 Switched Reluctance Motor (SRM) using the Finite Element Analysis (FEA) technique for the Electric Vehicle (EV) application is presented in this article. The motor's power rating is estimated from the tractive force of an e-rickshaw(3-wheeler). Optimizing the pole arc in SRMs is essential for obtaining an optimal balance of performance, efficiency, and operating smoothness. This makes it a vital part of SRM design. The motor performance is analyzed by fixing the stator pole arc while varying the rotor pole arc and vice versa. The main performance attributes like torque, torque ripple, torque per rotor volume, and efficiency of an 8/6 SRM with various pole arc values are examined using the transient FEA method. A sensitivity analysis is conducted to evaluate the range of variation in the performance parameters of the motor when the pole arcs vary. Various performance indices, such as torque, torque ripple (TR), efficiency, and Torque Per Volume (TPV), are considered for the analysis. The sensitivity analysis is carried out based on the transient analysis. Finally, based on the findings, the optimal combination of pole arcs is determined and analyzed the performance using the FEA method. An electromagnetic design tool called Infolytica MOTORSOLVE is used to construct the FEA models and extract the characteristics.

Comparative Performance Assessment of Sizing of Electric Motor through Analytical Approach for Electric Vehicle Application

For battery electric vehicle (BEV), electric motor is the only power source. The motor drive system in electric vehicle has many challenges like cost, weight, efficiency, detail torque speed characteristics, motor power rating. Accurate motor power rating prediction is very much necessary to fulfil the performance requirement of electric vehicle. Selection of oversized motor for Electric vehicle application results into overprice motor, more energy consumption and decline in vehicle range. Due to this there will expansion of battery size and increases the overall cost of vehicle. On the other hand, selection of undersized motor leads to poor vehicle performance that limits the drivability of vehicle. This paper gives detailed calculations of motor rating of electric motor. New approach is developed to predict the correct power rating of motor without affecting the desired vehicle performance. According to the requirement, accurate prediction of power rating of motor has been taken for cost efficient and upgradation the performance of motor. The work presented in this paper adopts a method of vehicle performance assessment on the basis of comparison with four different methods with new developed method. Traction motor is major & most expensive component of EV. Selection of motor play’s crucial role in the development of electric vehicle. Undersized and oversized motor results in rise in cost of motor which ultimately increases the cost of vehicle. But by using appropriate motor this cost been reduced up to 50-60% with performance enhancement.

An Unequal Split Dual Three-Phase PMSM With Extended Torque-Speed Characteristics for Automotive Application

High gradability and wide operating speed range are critical requirements for heavy-duty trucks and off-road electric vehicles. The motor power rating used for such applications can be reduced by selecting a motor with a wide constant power speed range (CPSR). However, permanent magnet synchronous motors (PMSMs) with wide CPSR have limited overloading capability. The operating speed range, as well as the overloading capability, can be improved by increasing the base speed of a low CPSR three-phase PMSM, which results in overdesign. Further, using multigear transmission to achieve a wide operating speed range with a low power motor increases system weight, drivetrain complexity, and maintenance requirement. This article proposes a dual three-phase interior PMSM with an unequal split winding configuration and zero degree winding displacement (uneq0-PMSM) to extend the constant power region and improve the overloading capability without any machine overdesign. The winding split ratio for the proposed configuration is decided to achieve the desired torque-speed characteristic shape for a given requirement. Further, a transition algorithm for smooth changeover between two-winding operation during low-speed and one-winding operation for high-speed is also proposed. The proposed concepts are experimentally validated on a 1.5-kW uneq0-PMSM with 1:3 winding split ratio.

Fuzzy logic field-oriented control of an induction motor and a permanent magnet synchronous motor for hybrid/electric vehicle traction applications

This paper presents a fuzzy logic field-oriented control scheme capable of controlling a hybrid/electric vehicle using a variety of traction motor topologies. The control scheme uses fuzzy logic controllers created in MATLAB/Simulink to control the vehicle's speed, the motor's current and the motor's flux which can be applied to an induction motor or a permanent magnet synchronous motor. A comparison between the fuzzy logic controllers and their PID counterpart's performance is also given. The fuzzy logic speed controllers provide comparable accelerator pedal and brake pedal angles to a person controlling the vehicle, leading to realistic vehicle dynamics. The simulations show that the fuzzy logic current and flux controllers can be used on any motor topology and power rating. This control scheme can be used during the design process of a hybrid or electric vehicle without the need for re-tuning whenever the motor configuration changes.

Fuzzy logic field-oriented control of an induction motor and a permanent magnet synchronous motor for hybrid/electric vehicle traction applications

This paper presents a fuzzy logic field-oriented control scheme capable of controlling a hybrid/electric vehicle using a variety of traction motor topologies. The control scheme uses fuzzy logic controllers created in MATLAB/Simulink to control the vehicle's speed, the motor's current and the motor's flux which can be applied to an induction motor or a permanent magnet synchronous motor. A comparison between the fuzzy logic controllers and their PID counterpart's performance is also given. The fuzzy logic speed controllers provide comparable accelerator pedal and brake pedal angles to a person controlling the vehicle, leading to realistic vehicle dynamics. The simulations show that the fuzzy logic current and flux controllers can be used on any motor topology and power rating. This control scheme can be used during the design process of a hybrid or electric vehicle without the need for re-tuning whenever the motor configuration changes.

Dynamic Modeling and Analysis of Power Sharing Control Strategy Based Fuel Cell/Battery Assisted Hybrid Electric Vehicle System

A dynamic modeling of Fuel cell/Battery assisted hybrid electric vehicle system is presented in this article and two suitable power sharing control strategies are integrated into the system with the objective of minimizing the fuel consumption and maximizing the battery life through its safe operating limit. This prominent goal is accomplished into the developed hybrid vehicle system by incorporating suitable control strategies without compromising the drivability of the vehicle. The proposed hybrid electric vehicle is capable of sustaining the peak power demand and utilizes the regenerative power in an effective manner for charging the energy storage system which could be possible with the relative power control strategy. In this paper, the proposed vehicle is modeled for its different hybridized configurations utilizing the model components such as dynamic PEM-Fuel Cell (PEMFC) system modeled by NARX network, Ni-MH battery system, DC/AC converters, PMAC traction motor and a power sharing controller. The proposed hybrid electric vehicle with two control strategies are modeled and evaluated in a MATLAB/Simulink environment. Simulations and comparison results shows that the PEMFC system assisted by battery during peak power demand accomplishes an improved fuel economy of hydrogen consumption and maximizes the battery SOC at the end of the driving schedule in a safe operating limit, which has a greater influence on the battery life cycle. Also, a comparative analysis is performed for the suitable selection of PMAC motor power rating to be adopted into the proposed vehicle model based on the fuel economy and efficient utilization of the battery.

Design of a Five-Phase Brushless DC Motor for a Safety Critical Aerospace Application

This paper describes a five-phase brushless dc (BLDC) motor designed for an electrohydrostatic actuation system (EHA) suited to the thin and optimized wings. The foundation of the design is a motor with fault tolerance and high reliability, compact structure, and low weight. The motor power rating is 12 kW at 12 000 rpm, and a “wet” form of construction is used where hydraulic oil is present in the motor to reduce the number of oil seals of the EHA for enhanced reliability and lifetime. The losses and thermal behavior are evaluated for an optimized design. Fault tolerance for BLDC motors is discussed. A five-phase motor has been manufactured, and test results are presented to validate the design.

Induction motor model selection criterion for parameter estimation in speed sensorless drive

In the parameter estimation algorithm of speed sensorless induction motor drive, the complete model of induction motor is replaced with its reduced order model by many researchers. However, no guideline is available in the literature for the selection of appropriate model under various operating conditions. In this paper, a detailed investigation is done regarding the possibility of such replacement for machines of any power rating and under different working conditions. A systematic comparative analysis is carried out which includes eigenvalue study on four machines of different power ratings with respect to changes in input frequency, slip and winding resistances. This is followed by Kalman's observability test and a computer simulation to demonstrate the relative performance of reduced order model when fed separately from an AC voltage source and then from a sinusoidal PWM inverter circuit. The study presented in this paper reveals that the selection of reduced order model should be made after considering various factors like motor power rating, ratio of leakage reactance to winding resistance, magnetising reactance, range of input frequency, range of operating slip depending upon the load and possible variation in the winding resistances. A comparative guideline is proposed in this regard which was found missing in the available literature.

Sensorless detection of mechanical faults in electromechanical systems

Practical early fault detection and diagnosis systems must exhibit high level of detection accuracy, while exhibiting acceptably low false alarm rates. Further, it is desirable not to make use of add-on sensors, and require minimal information regarding the specific machine component parameters and design. In this paper the development and experimental demonstration of a sensorless detection and diagnosis system is presented for incipient faults in electromechanical systems, such as electric motors. The developed system uses recent developments in dynamic recurrent neural networks and wavelet signal processing. The signals utilized are only the motor currents and voltages, whereas the transient mechanical speed is estimated from these measurements using a recently developed speed filter. The effectiveness of the fault diagnosis system is demonstrated by detecting a wide range of mechanical faults at varying levels of deterioration. Furthermore, the ability of the diagnosis system to discriminate between false alarms and actual incipient failure conditions is demonstrated. Experimental test results from small machines, 2.2 kW, and large machines, 373 and 597 kW, are presented demonstrating the effectiveness of the proposed approach to scale-up with motor power rating.

Determination of Power Rating of Three-Phase Induction Motors which Work Frequently, Intermittently, and Periodically Based upon Losses

This paper proposes a novel approach for determining the power rating of three-phase induction motors which work frequently, intermittently, and periodically based upon losses. The approach is also based on the following aspects: (1) there are several processes in a period; (2) the output power of a process varies with time; (3) the experienced time of a process, the switched-off time between two adjacent processes, and the cycle time are perhaps very short; (4) the rotational angle of the motor in a process is given; (5) the moment of inertia and the load torque of the motor drive system referred at the motor axis in a process are provided. The relationship between total losses and slip is formulated and the motor drive model differential equation presented. From the relationship and the differential equation, the heat due to losses of a process can be calculated, and then the total heat of a period can also be worked out. Accordingly, the average total losses of a period can be obtained by dividing the total heat of a period by the cycle time. Whether the rated power of the motor is fit for the application depends on the results from comparing average total losses with its rated value. To determine a motor's power rating, relevant parameters must be known. This paper introduces a mathematical model for extrapolating those figures from a manufacturer's catalog data. Data used in the estimation include rated levels for power, voltage, speed, current, efficiency, power factor, and the ratio relating the breakdown torque to the rated torque. Estimated parameters include equivalent circuit parameters and others. Among these are the magnetizing branch current of the per-phase " o " type equivalent circuit referred to the stator, rated core losses, rated mechanical losses, etc. The approach presented in this paper is used to determine the power rating of induction motors which operate in the interested application. Since the approach is based upon quantitative calculation of losses, overheating will not be caused. The approach is particularly effective when there is frequent starting, with brief experienced times and switched-off times. The method has successfully determined the power rating of the pusher drive motor in high-speed palletizers (the motor starts 24 times a minute).

A split-wound induction motor design to improve the reliability of PWM inverter drives

Stator windings have been designed for the three-phase induction motor to protect the PWM inverter bridge against simultaneous-conduction fault currents. Rather than adding inductance in each inverter leg to control fault currents, the design lets the primary leakage inductance of the motor stator windings perform the fault current control function. Appropriate separation of the windings in the stator slots increases the protection afforded. A 4 kW, two-pole, squirrel-cage induction motor, together with a 5 kW MOSFET inverter drive switching at 20 kHz, illustrates that excellent motor performance is possible with the new winding configurations. The motor power rating and torque/slip curves obtained at various speed settings with the new drive are close to those of a motor using standard stator windings. The protection afforded by the windings is shown to increase with the motor power and voltage rating.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A Simple but Reliable Loss Model for Inverter-Supplied Induction Motors

A semiempirical induction motor loss model is developed as a function of motor power rating. The aim is the estimation of losses caused by harmonic-distorted (e.g., PWM) current and voltage supplies. The model may consider harmonics between about 100 and 20 000 Hz and is constructed for power ratings between 1 and 1000 kW. Losses in rotor, stator, and iron (including most important stray losses) are separately estimated and suitably combined. This leads to a simple penalization factor for the time-harmonic currents, which is a function of motor size and which is quasi-linearly depending on harmonic frequency. Total losses are then calculated by the superposition of separate harmonic current or voltage effects. The penalization factor is experimentally verified. The importance of iron (plus stray) losses has been clearly shown. The model predictions are in close agreement with loss measurements on inverter-fed induction motors.

An improved stepped wave current source inverter

A new method of synthesizing stepped current waveform with (12n±l)th harmonic components is proposed. Suitable cascaded inverter configuration and commutation scheme are developed. Such a system requires a Y-Y transformer of 0·3 times the motor power (kVA) rating. The results have been experimentally verified.