Project 2 - Modeling of 3 phase Induction Motor Drive
EV REFRESHER BATCH-5
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DIRECT TORQUE CONTROL OF AN INDUCTION MOTOR
The electrical energy is supplied by a three-phase AC/DC diode rectifier connected to a 460 V, 60 Hz grid equivalent. The DC bus is connected to a three-phase, two-level converter. This converter generates the variable voltage and frequency required for the variable-speed operation of the 150 HP induction motor. In addition, a braking chopper is connected to the DC bus in order to dissipate the kinetic energy of the motor during deceleration.
Direct torque control (DTC) is a technique that allows you to instantaneously control the motor magnetic flux and its electromagnetic torque in a decoupled way. Controlling the torque directly permits accurate static and dynamic speed regulation. The main components of the DTC subsystem are:
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Flux and Torque Calculation — The stator flux linkage is estimated by integrating the stator voltages, and torque is calculated based on the estimated flux and the motor currents.
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Speed Regulator — The regulator compares the actual motor speed with the speed reference and generates the torque reference.
THE DESIGN PARAMETER TO BE TAKEN ARE
Design Parameters:
- Power = 100 HP
- DC Voltage = 800 V
- Output Voltage = 460 VRMS – line to line
- Initial Speed = 1500 RPM
- Final Speed = 1000 RPM
- Initial Load Torque = 10 Nm
- Final Torque=20 Nm
- Torque Step Time = 0.1 secs
FILE OF MATLAB MODLE PARAMETER
THE SIMULATION RESULT
Run the simulation and observe the waveforms on Scope2. Initially, the flux reference is set to 0.9 V.s.
At 0.1 s, the speed reference is set to 1500 RPM and the motor starts to accelerate. The motor speed precisely follows the speed reference, whose maximum rate of change is limited to 1200 rpm/s.
INPUT VOL ,CURRENT '
THE GRAPH SHOWS THE SPEED AND TORQUE
