EV Motors and Controllers - II — Lesson 4

This lesson covers the dynamics of a vehicle and how to derive motor specifications from vehicle specifications. It explains the forces acting on a vehicle, including the acceleration force, gradient force, rolling resistance friction, and air drag. The lesson also discusses how these forces affect the vehicle's speed and acceleration. It further elaborates on the concept of traction force, which is the force that the motor delivers to the vehicle. The lesson then delves into the calculation of the vehicle's steady-state speed and how the torque applied by the motor affects this speed. Finally, it explains how to plot the torque-speed curve and power-speed curve for the motor based on different operating modes.

Video Highlights

00:22 - Introduction and forces acting on a vehicle
02:35 - How the traction force and gradient force come from the motor and how it is related to the torque applied by the motor on the wheel
04:29 - Air drag affect and motor derived from vehicle dynamics
09:20 - How to plot the velocity and distance of a vehicle as a function of time
19:26 - How torue and power speed curves are generated and depicted
21:42 - Discussion on Energy consumption

Key Takeaways

- The forces acting on a vehicle include the acceleration force, gradient force, rolling resistance friction, and air drag.
- The traction force, delivered by the motor, contributes to the acceleration of the vehicle.
- The vehicle's steady-state speed can be calculated using the torque applied by the motor.
- The torque-speed curve and power-speed curve for the motor can be plotted based on different operating modes.
- The energy efficiency of a vehicle can be determined by the torque applied by the motor.