|PWM STRATEGIES OF THREE-LEVEL INVERTERS|
In the area of high voltages and powers, a high quality inverter-fed ac drive is more easily obtained by the use of three-level inverters. The inverter modulation strategy has an important influence on the quality of the drive therefore the selection of PWM method requires a special attention. The two- and three-phase carrier-based PWM strategies which insure the lowest motor harmonic current and torque pulsations are investigated for the whole voltage control area of the three-level inverters. It is shown that these PWM methods depend on the magnitude of the output voltage therefore the simple carrier-based realization requires certain approximations.
|Key Words:||three-level inverter, modulation strategies, carrier-based realization|