Blog

Motors used in EVs – BLDC, Induction, SRM, Permanent Magnet Motors for Electric Vehicles


Last updated: Feb 2020 by Narasimhan Santhanam



This posevnext-logo-v-smallt is a part of EV Next’s EV Perspectives.

EV Nexta division of EAI, is a leading market intelligence & strategic consulting firm for the Indian e-mobility sector.


 

Introduction

Different types of motors exhibit different characteristics, which makes it important to evaluate motors on some basic parameters for choosing a particular type of motor for an electric vehicle.

Electric motors used in electric vehicle should have important attributes like simple design, high specific power, low maintenance cost, and good control. Motors that are widely used by electric vehicle manufacturers are DC brushed motors, DC brushless motors, Induction (Asynchronous) motor, Synchronous motor and Switched Reluctance motor. The comparison of few motors are mentioned below

Motor Type Advantage Disadvantage Used by
Brushed DC Motor[1] Maximum torque at low speed
  • Bulky structure
  • Low efficiency
  • Heat generation at brushes
Fiat Panda Elettra (SeriesDC motor), ConceptorG-Van (Separatelyexcited DC motor)
Permanent Magnet Brushless DC Motor (BLDC)   
  • 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
Toyota Prius (2005)
Permanent Magnet Synchronous Motor (PMSM)
  • Operable in different speed ranges without using gear systems
  • Efficient
  • Compact
  • Suitable for in-wheel application
  • High torque even at very low speeds
  • Huge iron loss at high speeds during in-wheel operation
Toyota Prius, Nissan Leaf, Soul EV
Induction Motor (IM)
  • The most mature commutatorless motor drive system
  • Can be operated like a separately excited DC motor by employing field orientation control
  Tesla Model S, Tesla Model X, Toyota RAV4, GM EV1
Switched Reluctance Motor(SRM)Synchronous Reluctance Motor (SynRM)
  • Simple and robust construction
  • Low cost
  • High speed
  • Less chance of hazard
  • Long constant power range
  • High power density
  • Robust
  • 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
Chloride Lucas
PM assisted Synchronous Reluctance Motor
  • Greater power factor than SynRMs
  • Free from demagnetizing problems observed in IPM
  BMWi3
Axial Flux Ironless Permanent Magnet Motor
  • No iron used in outer rotor
  • No stator core
  • Lightweight
  • Better power density
  • Minimized copper loss
  • Better efficiency
  • Variable speed machine
  • Rotor is capable of being fitted to the lateral side of the wheel
  Renovo Coupe

Source 

 

Motor Type Power (kW) Base Speed (rpm) Minimum Speed (rpm)
HEV BEV
IM 57 93 3000 12,000
SRM 42 77 2000 12,000
BLDC 75 110 4000 9000

Power comparison of different motors having the same size    

Today’s automakers use three different types of electric motors in green cars: the BLDC motor, brushed DC motor, and AC induction motor.

Permanent Magnet motors for example provide high power density as well as very high efficiency. The downside is that these motors are very expensive and also suffer from problems such as demagnetization of the magnets if the temperature exceeds the curie point. The motor in Nissan Leaf is a permanent magnet motor

Induction motors on the other hand are cheap to manufacture and maintain but suffer from lower efficiency as well as power density compared to their Permanent Magnet counterparts. Tesla model S uses an Induction motor

In addition to these two there are also Synchronous Brushed motor and Switched Reluctance motor (used in Holden/ECOmmodore)

IMG_1276 

48 V 1kW BLDC Traction Motor suitable for Electric Auto-Rickshaws


 

evnext-logo-v-smallKnow more on how EV Next can assist your business in your strategy for the e-mobility and electric vehicles sectors, Here

Wish to know everything about India’s EV market from one place? Check out the India EV Expert Guide, an 800 page comprehensive guide to the Indian EV marketHere


 

See also the blog posts

Check out the following sections for comprehensive inputs on Indian EV ecosystem (click on each section for more details)


Categories: E-mobility, Electric Vehicles, EV Motors, EV Powertrain

Author - Narasimhan Santhanam


Thank you for reading this post – hope it was helpful. You can connect with me at narsi@eai.in. My detailed profile here and my LinkedIn profile here

Related Posts


About EAI and BioBiz for Bio-CNG

BioBiz for bio-CNG, EAI's specialized consulting division for bio-CNG, provides assistance in market research, strategy consulting, technology vendor/supplier finder assistance and more for the complete bio-CNG value chain – feedstock sourcing, logistics, pre-processing techniques, anaerobic digestion, biogas scrubbing, biogas upgradation, end user markets for bio-CNG and digestate, and more. Send a note to consult@eai.in if you wish to take BioBiz’s assistance for the Indian bio-CNG market.

About EAI & EV Next

EV Next, EAI's specialized consulting division, provides assistance in market research, strategy consulting, technology vendor/supplier finder assistance and more for the complete EV value chain - Li-ion & Lead Acid Battery Cells & Battery Packs, BMS, Battery Manufacturing equipment, EV charging station, battery swapping station, Li-ion & Lead Acid battery recycling, and for a range of electric vehicles - e-bikes, electric bicycles, electric scooters, electric motorbikes, electric autos, e-autos, e-rickshaws, electric trucks, electric LCVs, electric buses and more. Send a note to consult@eai.in if you wish to take EV Next assistance for the Indian electric vehicle market.



Devising Your EV Strategy: White Paper from EAI.


Leave a Comment ( 0 ) →



Leave a Comment

X

Name

Email

Mobile

Company Name

X

Name(*)

Email(*)

Mobile

Company Name

X

Name(*)

Email(*)

Mobile

Company Name

X

Name(*)

Email(*)

Mobile

Company Name

//