There is nothing so new about using electric vehicles, but there is more stress on contemporary features with the evolution of technology. For example, pollution control is one of the essential factors associated with electric vehicles. It is the inclusion of such features that makes any electric vehicle ready for future mobility. The electric vehicle propulsion system is the second most essential element after the vehicle batteries.

The motor is, what is capable of replacing the Internal Combustion engine. There is a drastic evolution in the sector of power electronics and control techniques. The same has also created some space for the different electric vehicle motors to be part of all-electric vehicles. Moreover, the electric motors used for auto applications must-have features like better power density, enhanced starting torques, better efficiency, etc.

 

What are the different kinds of motors that are compatible with electric vehicles?

1. DC series
2. SRM (Switch Reluctance Motor)
3. Brushless DC
4. Three- Phase AC Induction
5. PMSM (Permanent Magnet Synchronous Motor)

 

DC Series

The enhanced starting torque capacity of the DC Series EV motors makes it a better match for all traction applications. Moreover, it was a massively popular traction application motor during the 1900s. There are quite a few advantages of choosing the DC Series Motor over others. For example, the capacity to withstand the random increase in the load and smoother speed control are two of the most common benefits.

Apart from these two, there are other perks of using DC too, making it a decent traction motor. However, there are limitations to using these electric vehicle motors as well. The most common in this case is the fact that DC is incredibly expensive to maintain. The brushes and commutators that are required to use this are costly.

 

 

SRM (Switch Reluctance Motor)

This is a type of non-permanent reluctance motor that comes with a double saliency. SRMs are quite simple and strong for robust applications. The SRM EV motors contain rotors that are nothing, but steel laminated with permanent magnets or zero windings on them. As a result, the motor inertia reduces, enhancing the acceleration speed. The fact that SRMs are quite robust, they are the perfect match for high-speed application. Moreover, one of the essential requirements of electric vehicles is good power density, and SRM can offer the same. Besides, the heat generation majorly takes place through the stator, and so the motor cools down quickly.

The most critical limitation of SRMs is the intricacy of control and the enhancement around the switch circuit. There are also quite a few noise issues. Moreover, if the SRMs enter the commercial market even once, they can replace induction motors and PMSM shortly.

 

 

Brushless DC

This one is the same as standard DC electric vehicle motor and controllers, but the only difference is that there are permanent magnets in this case. The term brushless comes in this case because there is no brush arrangement or a commutator. Moreover, the commutation occurs electronically in brushless DC, so the BLDC electric vehicle motors are zero-maintenance.

There are traction features present in BLDC motors like better starting torque, excellent efficiency of approximately 95-98%, and more. This type of motor is more compatible with a high-power density pattern approach. Besides, the BLDC variety is the best match for EV applications mainly due to the various traction features.

There are two major types of BLDC motors: the outrunner type and the in-runner type.

In the first type, the stator is inside, and the rotor remains outside the motor. Another name of this type of EV motor is the HUB motor. The reason for the term is that the outer rotor is straight off connected with the wheels. There is no requirement for an external gear system for such motors. As a result, the vehicle’s overall weight reduces due to the absence of a separate gear system. There is also a lack of space that is mandatory for mounting the EV motor, specifically in electric scooters.

The in-runner type motor is where the rotor is inside, and the stator is not just like the case in all other conventional motors. There is a requirement for an external transmission device so that transferring power to the wheel becomes easier. Therefore, the in-runner system is a little lighter than its counterpart.

 

 

Three-Phase AC Induction

In this case, the EV motors lack an excellent starting torque like the one present in DC motors based on the fixed frequency and fixed voltage operations. However, there is a scope of alteration by utilizing various control techniques like Variable Frequency, or Field Oriented Control (FOC) procedures.

By using such control procedures, the maximum torque is available at the motor’s start, which is the perfect match for traction application. On the other hand, the induction motors with a squirrel cage have better longevity due to low maintenance. The designing of all induction motors is possible with an efficiency rate of 92-95%. The disadvantage of the induction motor is the requirement of an intricate inverter circuit, making the motor control more challenging while also becoming bulky in high power applications, thereby, reducing the power density.

 

 

PMSM (Permanent Magnet Synchronous Motor)

Being very similar to the BLDC EV motors, the PMSM also comes with permanent rotor magnets. Another similarity of PMSMs with BLDCs is traction features like high efficiency and better power density. The significant difference is that BLDC comes with a trapezoidal back and the PMSM comes with a sinusoidal end. Moreover, a PMSM (Permanent Magnet Synchronous Motor) has better power ratings most of the time. Therefore, it is the perfect match for high performing applications like buses and cars. Although the cost is high, PMSMs are substantial competition to the BLDC EV motors. The majority of the auto manufacturers prefer PMSM EV motors for their electric and hybrid vehicles.