ITCmc300 is a sensorless constant V/Hz system with closed
loop speed control using the reactive power Model Reference Adaptive System speed
estimator. It is implemented in a DSP from one of the TMS320F240x or TMS320F280x
processors.
The ITCmc300 unit generates all the PWM signals for power supply &
breaking and measures all the necessary currents and voltages. It communicates in
real time with a microcontroller that implements the application inteligence and user
interface.
The DSP measures two of the motor phase currents and the inverter DC-bus
voltage and calculates the three phase voltages of the motor using the switching
functions. It then estimates the current speed and generates a PWM set
corresponding to the desired speed on the V/Hz characteristic by adjusting both the
magnitude and frequency of stator voltages and maintaining the air gap flux at the
desired steady-state level (scalar control).
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