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Comparative analysis of electric motor drives employed for propulsion purpose of Battery Electric Vehicle (BEV) systems

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This paper presents an analysis of electric motor drives for the propulsion system of a battery electric vehicle (BEV). It offers a comprehensive review and mathematical analysis of both AC and DC motor drives commonly used in electric vehicle (EV) applications. Various types of electric motor drives have been utilized for EV propulsion, and among them, the Permanent Magnet Synchronous Motor (PMSM) drive stands out as the optimal choice. The PMSM drive demonstrates superior performance and numerous advantages, including a robust structure, high efficiency, compact size, reduced maintenance costs, and minimal torque ripple. These characteristics make it a more suitable option for EV propulsion compared to other motors. This study investigates the performance of the PMSM drive in comparison to other competitive electric motor drives used in EV propulsion systems, namely the Brushless DC Motor (BLDCM), the Induction Motor (IM), and the Switched Reluctance Motor (SRM). The evaluation focuses on key criteria for electric motors—output power and torque densities, essential for effective application in EV propulsion systems. The paper introduces novel mathematical and analytical relationships between two prominent PM motor families: the PMSM and the BLDCM. Both motors are highly competitive in terms of power and torque output. The mathematical analysis and graphical plot simulation results demonstrate that the PMSM drive offers the highest power and torque densities among the three motor drives. Specifically, the PMSM drive exhibits 29.90% greater power and torque densities than the BLDCM drive, 88.68% greater than the SRM drive, and an impressive 200% greater than the IM drive, all under the same operating parameters such as power factor, size, rating, and efficiency. These findings highlight the significant advantages of the PMSM drive, positioning it as a superior choice for electric vehicle propulsion systems.
*Corresponding author: Simon Fekadeamlak Gebremariam
Copyright © 2023 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0.
Comparative analysis of electric motor drives employed for propulsion purpose of
Battery Electric Vehicle (BEV) systems
Simon Fekadeamlak Gebremariam * and Tebeje Tesfaw Wondie
Department of Electrical and Computer Engineering, Woldia Institute of Technology (WiT), Woldia University, Ethiopia.
International Journal of Science and Research Archive, 2023, 10(02), 10971112
Publication history: Received on 11 November 2023; revised on 22 December 2023; accepted on 25 December 2023
Article DOI: https://doi.org/10.30574/ijsra.2023.10.2.1074
Abstract
This paper presents an analysis of electric motor drives for the propulsion system of a battery electric vehicle (BEV). It
offers a comprehensive review and mathematical analysis of both AC and DC motor drives commonly used in electric
vehicle (EV) applications. Various types of electric motor drives have been utilized for EV propulsion, and among them,
the Permanent Magnet Synchronous Motor (PMSM) drive stands out as the optimal choice. The PMSM drive
demonstrates superior performance and numerous advantages, including a robust structure, high efficiency, compact
size, reduced maintenance costs, and minimal torque ripple. These characteristics make it a more suitable option for EV
propulsion compared to other motors. This study investigates the performance of the PMSM drive in comparison to
other competitive electric motor drives used in EV propulsion systems, namely the Brushless DC Motor (BLDCM), the
Induction Motor (IM), and the Switched Reluctance Motor (SRM). The evaluation focuses on key criteria for electric
motorsoutput power and torque densities, essential for effective application in EV propulsion systems. The paper
introduces novel mathematical and analytical relationships between two prominent PM motor families: the PMSM and
the BLDCM. Both motors are highly competitive in terms of power and torque output. The mathematical analysis and
graphical plot simulation results demonstrate that the PMSM drive offers the highest power and torque densities among
the three motor drives. Specifically, the PMSM drive exhibits 29.90% greater power and torque densities than the
BLDCM drive, 88.68% greater than the SRM drive, and an impressive 200% greater than the IM drive, all under the same
operating parameters such as power factor, size, rating, and efficiency. These findings highlight the significant
advantages of the PMSM drive, positioning it as a superior choice for electric vehicle propulsion systems.
Keywords: BEV; PMSM drive; BLDCM drive; SRM drive; IM drive; Power density; Torque density
1. Introduction
Electric motors are the brain and core element of an EV. The electric motors that are used for automotive purposes need
to meet certain characteristics like high power density, high efficiency, high speed ranges, low torque ripple, high
starting torque, high reliability, and reduced weight. Hence, all available electric motors for EV propulsion d o not have
equal importance, as all have their own merits and demerits. Regarding applications for EV propulsion systems, PMSM
drive, BLDC motor, Induction motors, Reluctance motors, and Brushed DC motors are widely used.
1.1. Brushed DC Motor
A brushed DC motor is an internally commutated electric motor that uses a mechanical commutator and an electric
brush for contact and is powered by a direct current power source. Brushed motors were the first commercially
important application of electric power to drive mechanical energy, and DC distribution systems have been used to
power motors in commercial and industrial facilities for more than a century. The speed and torque characteristics of a
brushed motor can be changed depending on how the field is connected to the power supply to produce a constant
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speed or a speed that is inversely proportional to the mechanical load. This makes them able to achieve high torque at
low speeds. Brushed motors are still applicable in electric propulsion (traction) systems, massive cranes, paper
machines, and steel rolling mills. Even though they have good speed torque characteristics, these motors suffer from
wear and tear due to the presence of brush contacts. The wearing of the commutator segments occurs because o f the
continuous cutting with brushes, and hence the friction between the brushes and commutator segments limits the
maximum speed of the motor. Thus, brushed DC motors have low efficiency, low reliability, and a higher need for
maintenance and repair, mainly due to the presence of the mechanical commutator segments and electrical brushes,
even if interesting advancements have been made with slippery contacts. Furthermore, brushed DC motors have a lower
power density when compared to PMSM, BLDC motor, SRM, and induction motors for use in electric vehicles [1] [2].
a
b
Figure 1 (a) Cut-away view of Brushed DC Motor [3] (b) Speed Vs Torque Vs Power curve [4]
1.2. Switched Reluctance Motor (SRM)
The switched reluctance motor (SRM) is a special-purpose electric motor family designed to run by reluctance torque,
i.e., torque is produced in such motors by a variable reluctance technique. Unlike the conventional brushed DC motor
types, electric power is delivered to the stator windings rather than the rotor conductors. When stator coils (windings)
are energized, variable reluctance is set up in the air gap between the stator and the rotor. Hence, the rotor tends to
move to a position of least reluctance, thus causing torque. This significantly simplifies mechanical design as electric
power does not have to be delivered to the moving part (rotor). However, it complicates the electrical design as some
sort of switching system needs to be used to deliver power to the different windings. SRM can be applied for different
purposes, like robotic control applications, washing machines, vacuum cleaners, and automobiles. But, due to its
electrical design complexity, high torque ripple, audible acoustic noise and vibration problems, lower power density,
and lower efficiency, SRM is mostly applied to electric vehicle propulsion systems due to its high starting torque [5] [6].
a
b
Figure 2 (a) Appearance of switched reluctance machine 8/6. [7] (b) Torque speed characteristics of SRM [8]
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1.3. Induction Motor
An induction motor, also known as an asynchronous motor, is a type of AC electric motor in which the electric current
in the rotor required to develop torque is generated by electromagnetic induction from the revolving magnetic field of
the stator winding [9]. Because of its high efficiency, superior speed control, lack of commutators and low cost, three-
phase induction motors are commonly utilized in electric vehicles [10]. But, compared to the PMAC motor families, they
have large rotor inertia, higher torque ripple, lower power and torque density, and hence lower speed dynamic response
[11].
a
b
Figure 3 (a) Cut-away view of squirrel cage IM [12]; (b) Speed Vs Torque Vs Power curve of IMs [13]
1.4. BLDC Motor
BLDC motor is an AC permanent magnet motor family with a trapezoidal back EMF waveform. Unlike the brushed DC
motor, the BLDC motor doesn’t have brushes, slip rings, and field windings, and the mechanical commutation is replaced
by electronic commutation, which makes it have higher efficiency, less maintenance, reduced weight, and a compact
size [14]. In comparison to the above three motors, the BLDC motor offers higher power density, higher dynamic
response, larger torque output, lower torque ripple, high speed ranges, higher reliability, and less maintenance needs.
Hence, the BLDC motor is suitable for EV propulsion systems.
a
b
Figure 4 (a) Cut-away view of BLDC motor (b) Speed versus Torque versus Power curve [15]
1.5. PMSM Drive
A permanent-magnet synchronous motor (PMSM) is an AC motor family that uses permanent magnets instead of
electromagnets, which are embedded in the steel rotor to create a constant air gap magnetic field. The stator carries
windings connected to an AC power supply to generate a rotating magnetic field (as in the case of asynchronous motors).
It has a multiphase stator (usually three phase and/or, in some cases, five phase), and the stator electrical frequency is
directly proportional to the rotor speed in steady state. At synchronous speed, the rotor poles lock onto the rotating
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magnetic field. PMSM has the same principle of operation as that of the classical synchronous machine except that it has
permanent magnets in place of the field winding and has no rotor conductors, which leads it to have zero copper loss in
the rotor. The adoption of permanent magnets in the rotor dynamics improves efficiency, avoids the requirement for
brushes and slip rings, as well as alleviates the complications associated with control techniques, especially vector
control. In such motors, neodymium magnets are the most widely employed magnets. Although, in recent years, due to
the significant volatility in the pricing of neodymium magnets, much study has focused on ferrite magnets as an
alternative [16] [17] [18]. The combination of an inner permanent magnet rotor and outer windings offers the
advantages of low rotor inertia, reduced motor size, compact structure, efficient heat dissipation, high power density,
high efficiency, high torque inertia ratio, high speed range, high air-gap flux, and no conversion spark (since there are
no brushes) over other kinds of electric motors [17]. Thus, PMSM drive tops all the electric motor preferences available
for EV propulsion systems.
a
Figure 5 (a) Cutaway view of PMSM [19] (b) Speed vs Torque vs Power graph [20]
The internal parts of the stator and rotor along with the permanent magnet can be seen as in figure (6):
a
b
Figure 6 Constructions of a PMSM (a) Standard (b) Inside-out [21]
2. Drivetrain of electric vehicles
The electric vehicle drivetrain requirements and specifications available in the world market are given in tables 1 and
2 [22] [23]. From these tables, it could be observed that PMSM, BLDC motor, and induction motor are the most popular
from the manufacturer’s vantage point. An overall comparison of electric motors based on EV requirements is required
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to select an appropriate motor that can mostly fulfill the EV motor technology requirements. The following are the most
important criteria and required features of electric vehicle motor drives:
High dynamic performance;
High power density;
Fault tolerance capability;
Reduced power loss and high overall efficiency;
Reduced size and weight;
Cost-effective;
Reduced maintenance and operating costs;
Electromagnetic interface (EMI) suppression capability in motor controllers;
Low/reduced torque ripples;
High produced torque at low speed,
Enhanced energy management system for regenerative braking system;
High reliability and robustness of the motor at different operating states;
Table 1 Available Electric Vehicles in the world market [24]
No
Name of EV
Electric Motor type
Manufacturer
Company
Passenger/seat
capacity
Country
1
Fiat Panda Elettra
Brushed DC motor
Fiat
5
Italy
2
Buddy
Brushed DC motor
Buddy electric
3
Norway
3
PSA Peugeot-Citroën/
Berlingo
Brushed DC motor
PSA Group
5 or 7
France
4
Tesla Model S
Induction motor
Tesla
5
USA
5
Tesla Model X
Induction motor
Tesla
5
USA
6
Toyota RAV4
Induction motor
Toyota
5
Japan
7
GM EV1
Induction motor
General Motors
2
USA
8
ZeCar
Induction motor
Stevens Vehicles
5
UK
10
Toyota Prius
PMSM
Toyota
5
Japan
11
Nissan Leaf
PMSM
Nissan
5
Japan
12
Kia Soul EV
PMSM
Kia
5
S/ Korea
13
Honda Insight
PMSM
Honda
5
Japan
14
Lucas Chloride
SRM/ SynRM
Lucas chloride EV
systems
5
UK
15
BYD E6
BLDC
BYD Auto
5
China
16
Mitsubishi i-MiEV
BLDC
Mitsubishi
4
Japan
17
BMW-i3
BLDC
BMW
5
Germany
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Table 2 Requirements of electric motors used in EV [23]
Type of
Motor
Max. Speed
(Km/hr)
Advantages
Disadvantages
Brushed DC
motor
Up to 80
Maximum torque at low speed
Bulky structure
Low efficiency
Heat generation at brushes
Induction
motor
Up to 160
The most mature commutator-less motor drive
system
Can be operated like a separately excited DC
motor by employing field orientation control
Complicated control
Always lagging power factor
Low efficiency with lighter
loads
PMSM
Up to 160
Operable in different speed ranges without
using gear systems
Highly Efficient
Compact size
Suitable for in-wheel application
High torque even at very low speeds
High power density
Huge iron loss at high speeds
during in-wheel operation
SRM/
SyrnRM
Up to 160
Simple and robust construction
Low cost
High speed
Less chance of hazard
Long constant power range
High power density
Fault tolerant
Efficient
Small
Very noisy
Low efficiency
Larger and heavier than PM
machines
Complex design and control
Problems in controllability and
manufacturing
Low power factor
BLDC motor
Up to 160
No rotor copper loss
More efficiency than induction motors
Lighter
Smaller
Better heat dissipation
More reliability
More torque density
More specific power
Short constant power range
Decreased torque with increase
in speed
High cost because of PM
2.1. Advantages of PMSM drive over the corresponding motors:
The advantages of PMSM drive over the corresponding alternative motors types for EV propulsion applications are: [25]
[26] [27]
Advantages of PMSM drive over Brushed DC motor
Lighter in weight and smaller (compact) size;
Have less audible acoustic noise;
Spark-less and no fire hazards due to the elimination of carbon brushes;
Higher torque and power densities;
Comparatively negligible torque ripples;
Better heat regulation and dissipation;
Longer life span; and
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Higher dynamic response;
Advantages of PMSM drive over IM
Better dynamic performance characteristics, for it has lower rotor inertia;
Higher power and torque densities for medium power applications like EVs, resulting smaller and compact size;
Due to its higher torque to volume ratio it has better geometrical integration in to the engine cabinet, hence
reduces the overall curb weight of the vehicle;
Has the ability to maintain full torque at low speeds;
Lower current rating for inverter and improved battery utilization;
Due to its higher efficiency at low speeds, it is suitable for city automobiles, where frequent start-stop at low
speed. Hence, improving battery energy utilization and driving range;
Higher power factor;
Better heat dissipation; and
Less noisy and more reliable.
Advantages of PMSM drive over BLDC motor
Reduced current and torque ripple.
Higher power to weight ratio.
Higher and smooth torque and low noise due to lower ripples.
Highly efficient and more reliable.
Higher power density that would help in reducing the size and weight of the motor. Thus, PMSM drive gets
better than BLDC motor in terms of dynamic performance to use in EVs.
In general, the performance comparison of PMSM drive with the possible electric motors used in EV propulsion systems
can be summarized as shown in figure (7) based on ten motor performance characteristics, each with a maximum of ten
points, for a total of one hundred points [28]. Higher values indicate better performance. According to the findings,
PMSM drive is the best option for high-performance electric vehicles as a drivetrain.
Figure 7 Performance comparison of electric motors out of 100 points
3. Methodology
The methodology generally consists of the type and specifications of the Battery Electric Vehicle (BEV) chosen for
comparison, overall assumptions, and the major points considered to proceed with the comparison of the available
electric motor drives employed for the propulsion of the BEV system.
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3.1. Type and specification of the EV
To pursue with the performance analysis of the motors, a specific type of EV has been chosen (i.e., Nissan Leaf S Plus
BEV) and the motor rating requirements of the EV is given in table 3 [33] [34]:
Table 3 Motor specification for Nissan Leaf S Plus EV [33] [34]
Parameters
Description/Values
Model Type
EM57
Company
Nissan
Electric Motor Type
3 phase AC synchronous/ Permanent Magnet
Voltage rating
360 V-
Rated Power
80 kW
Rated Current
223 A
Rated Speed in rpm/ Base Speed
4600 r.p.m and base speed of the EV 320 rad/sec
Maximum Torque @ 80 kW
250 Nm
3.2. Assumptions Made
The general assumptions made to make comparisons b/n the motor drives are:
Electrical and mechanical loading of each motors under comparison are kept the same.
The same machine design and construction is considered.
The size, rating, power factor, and efficiency of each motor drive are considered to be the same.
The major comparing points this paper addresses are the power and torque density of each motor, which are required
to be as high as possible for EV applications. Therefore, each motor is compared based on its output power and torque.
4. Mathematical analysis, result and discussion
This section includes the mathematical and analytical analysis performed between the Permanent Magnet Synchronous
Motor (PMSM) and the other three motors. Subsequently, MATLAB simulation plots are generated from the
mathematical relations, and discussions are made accordingly.
4.1. PMSM Vs BLDC
In the above sections , it is shown that PMSM drive is the best selection for EV compared to Brushed DC motors, SRM,
Reluctance motors, Induction motors and BLDC motors. However, the ac synchronous family, i.e., the BLDC motor, is
highly competent with the PMSM drive, specifically in terms of its simple controllability and cost. Although the two
motors are highly competent to each other, PMSM has better features in terms of having a higher power output and
higher torque density. In this section a novel mathematical relationships b/n the two motors is addressed, hence the
power output ratio for the two motors is derived as follows, which is based on the equal cupper loss principle of their
stators. Let Im(PMSM) and Im(BLDC) be the peak value of PMSM stator currents and the peak values of BLDCM stator currents
respectively. The rms values of these currents can be calculated using equation (1):
 󰇛󰇜
 󰇛󰇜
……….. (1)
By equating the cupper losses of the two motors and substituting for the currents in terms of their peak currents, would
yield:


……….. (2)
Substituting the rms currents in to equation (1) and solving for the peak current of PMSM drive in terms of the peak
current of BLDC motor gives:
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󰇛󰇜 󰇛󰇜
…………(3)
The maximum values of the induced EMF in BLDC motor and PMSM drive are equal and denoted by E m. In the case of
BLDC motor, only two phases conduct at the same time, and output power is contributed by the two phases only. On the
contrary, the PMSM drive has currents in all its phases and, hence, power output is contributed by all three phases.
Considering power angle at 90o for maximum power, where  becomes unity; the output power of the two motors
is given as:
 󰇛󰇜………… (4)
 󰇛󰇜……………(5)
 

 ……… (6)
The above relationship shows that the output power density of the PMSM drive is much greater than that of the BLDC
motor, i.e., considering a unity power factor for the BLDC motor, the PMSM drive output power density is superior by
over twenty percent, to be exact, 29.90%.
Figure 8 Output torque density and output power of PMSM drive and BLDC motor
If a base speed of 320 rad/sec with rated power of 80 kW and a maximum torque of 250 Nm of PMSM drive with the
same cupper loss compared with its counter BLDC motor is considered, the output torque and output power of the two
motors can be summarized as in figure (8). From this figure, it can be observed that the power output and torque density
of the PMSM drive is larger than that of the BLDC motor by 29.90%, which makes it suitable for applications that require
larger torque outputs like EVs, aircrafts, train, aerospace and industries.
4.2. PMSM Vs SRM
The performance comparison between PMSM drive and doubly salient SRM, in terms of power and torque density for
EV propulsion system applications, is done by considering the same size, rating, and design for the two machines. Hence,
the following equations are given to pursue the comparison.
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The electrical and mechanical output power of PMSM drive is determined using equations (7) and (8) [29].
󰇛󰇜 󰇡
󰇢
󰆹 ………… (7)
󰇛󰇜 󰇡
󰇢

 ………… (8)
Where is the efficiency of the PMSM drive, is the number of stator phases,
is the maximum phase air-gap EMF
(volt),
󰆹maximum value of the stator phase current (Amp),  is the winding distribution factor of the motor which is
given to be 0.9,
 is the fundamental air-gap flux density (Tesla),
is the peak current density or loading (A/m2),
is stator inner diameter or air-gap diameter (mm), is the effective stack length (m), is angular speed (rad/sec) and
 is the power factor of the motor.
The power developed by the corresponding SRM drive is deduced using equation (9). The equation is a simplified form
that is done considering that only one phase conducts simultaneously () [30].
󰇛󰇜 
 

 ………… (9)
Where is the efficiency of the SRM drive, is global coefficient which is deduced to be (),
is the air-gap flux
density of the motor (Tesla),
is current density or loading (A/m2), is stator inner diameter or air-gap diameter
(mm), is the effective stack length (m), is angular speed (rad/sec) and  is the power factor of the motor.
The relative power density ratio between the two machines topologies can be determined if the linear current
density A, the air gap flux density power factor, rotational speed and the mechanical parameters are the same for
both machines PMSM and SRM:
Hence, the ratio of the power densities for the two motors are obtained as [30]:


󰇛󰇜


󰇡
󰇢
 ………… (10)


󰇛󰇜
󰇡
󰇢 ………… (11)
In accordance with the general assumptions made and for the sake of simplicity, it is considered that the motors have
the same efficiency and power factor. As a result, the power density ratio is determined as follows:

 
  ………… (12)
  ………… (13)
Equations (12) and (13) denote that the power density of the PMSM drive is 1.88 times the power density of the SRM
drive, or that the power density of the SRM drive is 0.5319 times the power density of the PMSM drive.
To compute the torque density of the motors, the general equation (14) can be used [31]:
 ………… (14)
For the PMSM drive, the torque density can be obtained using equation (15) [32]:
 󰇡
󰇢

 ………… (15)
󰇡
󰇢󰇛󰇜

 ………… (16)
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For the SRM drive, the torque density can be obtained using equation (17) [31]:
 
 
󰇛
󰇜 ………… (17)
The ratio of the torque densities for the two motors can be obtained by using equation (18).


󰇛󰇜



󰇛
󰇜 ………… (18)

  
  ………… (19)
In short, once the power density is obtained the torque density can be deduced using the relation:
………… (20)
Since the motors are considered to have the same speed, the ratio of torque density will be the same as the ratio of
power density of the motors.
Figure 9 Output torque density and output power density of PMSM drive and SRM drive
For a base speed of 320 rad/sec with rated power of 80 kW and a maximum torque of 250 Nm of PMSM drive with the
same efficiency, power factor and mechanical parameters compared with its counter SRM drive is considered, the
output torque and output power of the two motors can be summarized as in figure (9). From the figure, it can be noted
that the power output and torque density of the PMSM drive is larger than that of the SRM drive by 88.68 %. As a result,
the PMSM drive is superior compared to SRM drive for EV propulsion systems, which require higher torque and power
densities.
4.3. PMSM Vs IM
The power density of a PMSM drive is two to three times the power density of an induction motor for the same rating,
size, and design of the two motors [25] [26].
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1108
Hence, considering the power density of the PMSM drive to be twice that of the induction motor, the corresponding
power and torque densities will become:
  ………… (21)

 
  ………… (22)
To pursue the performance comparison between the two motors, the rotational angular speed is considered to be the
same for the two motors, which results direct relationship b/n the power and torque densities. Thus, the torque density
of the PMSM drive will be twice that of the induction motor.
  ………… (23)

 
  ………… (24)
For a base speed of 320 rad/sec with rated power of 80 kW and a maximum torque of 250 Nm of PMSM drive with the
same efficiency, power rating, power factor and mechanical parameters compared with its counter IM drive is
considered, the output torque and output power of the two motors can be summarized as in figure (10). From this figure,
it can be noticed that the power and torque density of the PMSM drive is larger than that of the IM drive by 200%.
Consequently, the PMSM drive is superior compared to IM drive for EV propulsion systems, which require higher power
and torque densities.
Figure 10 Output torque density and output power of PMSM drive and IM drive
Generally, the performance comparison of the PMSM drive with BLDCM, SRM, and IM in terms of torque and power
densities is given in figure (11). The maximum possible output power and torque densities of the four motors when
chosen to be applied to the selected EV (i.e., the Nissan Leaf S Plus) is summarized in table 4. From figure (11) and table
4, it can be concluded that the PMSM drive is the best choice for electrical systems that require high power and torque
densities, like for EV propulsion systems.
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1109
Table 4 Summary of the power and torque densities of the four motors for the same physical parameters
Motor type
Max. Power Density
Max. Torque Density
PMSM drive
80 kW
250 Nm
BLDCM drive
61.6 kW
192.5 Nm
SRM drive
42.552 kW
132.975 Nm
IM drive
40 kW
125 Nm
Figure 11 Performance comparison of PMSM, BLDCM, SRM and IM drives in terms of Power and Torque densities
Figures (12) and (13) depict the comparison chart of the four motor drives in terms of power and torque densities,
where PMSM drive is superior of the three motor drives. The power and torque density of the PMSM drive is 29.90 %
superior than the BLDCM drive, 88.68% superior than the SRM drive and 200% superior than the IM drive.
International Journal of Science and Research Archive, 2023, 10(02), 10971112
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Figure 12 Comparison chart of the four Motor drives in terms of Power densities
Figure 13 Comparison chart of the four Motor drives in terms of torque densities
5. Conclusion
In this paper, a comprehensive investigation and analysis of electric motor drives employed for electric vehicle (EV)
applications has been conducted. The paper addresses the advantages and drawbacks of each motor drive, providing a
detailed comparison. Analytical and mathematical relationships between the Permanent Magnet Synchronous Motor
(PMSM), Brushless DC Motor (BLDCM), Switched Reluctance Motor (SRM), and Induction Motor (IM) drives have been
established for the purpose of comparison. Operational characteristics, specifically power and torque densities have
been subjected to mathematical and graphical analysis and simulation to establish a hierarchy among the electric
motors. The paper also delves into the mathematical and graphical analysis to demonstrate the superiority of the PMSM
drive over BLDCM, SRM, and IM in terms of power and torque densitiescrucial factors determining the suitability for
electric vehicle propulsion systems. According to the findings, the PMSM drive exhibits a significant advantage and
preference over the other three motors in terms of power and torque output. To further illustrate the comparison, the
Nissan Leaf S Plus BEV with a rated power and torque of 80 kW and 250 Nm, respectively, is considered. Based on the
mathematical relations indicating that the BLDCM has 0.7698 of the power and torque output of the PMSM, the SRM has
0.5319, and the IM has 0.5, it is evident that the PMSM emerges as the top choice for the propulsion of EV systems.
International Journal of Science and Research Archive, 2023, 10(02), 10971112
1111
Therefore, considering the comprehensive analysis and the specific comparison with the selected EV, the PMSM drive
has been identified as the number one choice for electric vehicle propulsion systems.
Compliance with ethical standards
Acknowledgement
We express our gratitude to everyone who supported and encouraged us in pursuing this research. Additionally, we
extend our thanks to IJSRA for their continuous and steadfast communication, as well as their valuable feedback, which
contributed to the publication of this research article.
Disclosure of conflict of interest
The authors declare no conflict of interest.
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