Week 3 Session 7
Q1. Compare the different motors used in EV and list down the advantages and disadvantages of each.
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| DC | IM | PMSM | SRM | |
| Power Density | Low | Medium | Very High | Medium |
| Efficiency | Low | Medium | Very High | Medium |
| Controllability | Very High | Very High | High | Medium |
| Reliability | Medium | Very High | High | Very High |
| Cost | Low | Very Low | High | Low |
Advantages & Disadvantages :
1. Brushed DC Motor
| Advantages | Disadvantages |
|
- It gives max torque at low speeds. - Simple control methods. |
- High maintenance cost due to brush assembly. - Low efficiency & limited speed due to friction in brushes. - Bulky Structure. |
2. BLDC Motor.
| Advantages | Disadvantages |
|
- Compact Size. - No rotor copper loss. - High efficiency than brushed type. - Low maintenance cost. |
- Expensive due to electronic control system. - Centrifugal forces on rotor magnets. - Temperature constraints for PM limits torque production. |
3. Permanent Magnet Synchronous Motor (PMSM).
| Advantages | Disadvantages |
|
- Can be used without gear system in different speed range. - More efficient, simple construction and compact. - Best suitable for in-wheel application. |
- High cost due to PM. - Eddy current loss in PM during high speed operation. - Centrifugal forces on PM at speed and risk of damage. |
4. Induction Motor.
| Advantages | Disadvantages |
|
- Simple and rugged construction. - Only one rotating part. - Simple maintenace and low cost. - High starting torque and self starting. |
- Single phase IM is not self starting. - Speed control is difficult. - Low power factor due to high magnetising inrush current. |
5. Switched Reluctance Motor (SRM).
| Advantages | Disadvantages |
|
- Wide constant power operation region. - Fault tolerance. - Simple Maintenance. |
- Increased vibrations and noise. - Complex control. |
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