D and Q Axis in Motors — Lesson 6

This lesson covers the concept of D and Q axis in motors, specifically focusing on the Permanent Magnet Synchronous Motor (PMSM) and Interior Permanent Magnet Synchronous Motor (IPMSM). It explains why these axes are important, how they are used to calculate torque, and their physical presence in the motor. The lesson also delves into the interaction between the rotating rotor, oscillating currents, and the magnetic field, which collectively produce torque. It further discusses the concept of changing the reference frame to the rotor to simplify the understanding of motor operations. The lesson concludes with the explanation of voltage equations and the equivalent circuit of an IPMS motor.

Video Highlights

00:18 - Introduction
00:52 - The d-q axis frame
06:07 - Discussion on the relationship between voltage, current, and torque in a motor
08:10 - Two types of flux change
15:48 - Explanation of the equivalent circuit analysis

Key Takeaways

- The D and Q axis are crucial in calculating torque in motors.
- The interaction between the rotor, oscillating currents, and the magnetic field results in torque.
- Changing the reference frame to the rotor simplifies the understanding of motor operations.
- The voltage in each axis is influenced by the current or flux in the perpendicular axis, leading to cross-coupling.
- The equivalent circuit of an IPMS motor includes a voltage source, resistive drop, back EMF term, and an inductor.