10-04-2017, 08:47 PM
TO DEVELOP A SPEED CONTROL SYSTEM FOR AC MOTOR USING MULTILEVEL (3,5,7) INVERTERS.
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INTRODUCTION
Dc motor have been used during the last century in industries for variable speed control applications because its flux and torque can be controlled easily changing the field and armature current respectively.
Farther four quadrant operation of induction motor was achieved.
Induction motor popularly used in industries due to ruggedness and robustness.
To reduces the harmonics we use the multilevel inverter.
The performance of the multilevel inverter is better than a classical inverters
The THD of the multilevel inverter is low as compare to classical inverter
features
They are suitable for high-voltage and high-current applications
They have higher efficiency because the devices can be switched at low frequency
No EMI problem exists
Power factor is close to unity
CONCLUSION
Microcontroller based multilevel inverter fed induction motor drive is simulated using Matlab Simulink and the hardware is implemented on two prototype boards. The multilevel inverter output has reduced harmonics. This reduces the heat generated in the stator winding of the induction motor. The torque of the motor is improved due to the elimination of the fifth harmonic, which produces negative torque. A Microcontroller based gating circuit generates the pulses required by the inverter. The induction motor drive system is successfully fabricated and tested..