An electrical motor drive refers to the system that controls the speed, torque, and direction of an electric motor. The primary purpose of motor drives is to regulate the performance of electric motors in various applications, such as industrial machinery, robotics, electric vehicles, and HVAC systems. Motor drives are essential for achieving precise control and efficiency in motor-driven systems.
Regulating the electric power sent to an electric motor is a task performed by high-speed switching transistors inside a motor drive, modulating the pulse-width of a high-frequency square wave to the motor. The high-speed switching happening inside of a motor “drive” circuit results in the drive drawing current from the AC power source as high-frequency pulses rather than as sinusoidal waves. These current pulses tend to distort the voltage of the AC power source so that other devices powered by the same AC source will “see” high-frequency noise on the power lines. This is true for DC and AC motor drives alike:
In order to mitigate this noise line reactors are used.
Further Reading/reference:
- Application of line reactors to AC and DC motors
- Download complete PDF article on Motor Drive Features and Application of Line Reactors Handbook PDF Download
- DC injection braking
- Dynamic braking of AC Induction Motors
- Regenerative braking of AC Induction Motors
- Braking using Plugging