1 Answers
The limitations of stepped wave inverters are:
- Presence of low-frequency harmonics–Increases motor losses at all speeds—Required to derates the motor.
- Develops pulsating torques due to 5th, 7th, 11th, and 13th harmonics–Cause jerky motion of rotor at low speeds.
- At low speeds harmonic content will increase–Machine saturates at light loads due to high (V/f) ratio–Causes overheating of the machine at low speeds.