2 ACI Motor Control Benchmark Application

The ACI Motor Control Benchmark simulates the sensorless AC induction motor control application. The application performs all the typical operations: analog-to-digital converter (ADC) reads for sensing phase currents, transform blocks that operate on the sensed current and PWM writes to control phase voltages. No special external hardware is needed to provide stimulus as the application has a block of code that models the behavior of an induction motor. To simulate closed loop behavior, the expected current from the motor model is fed into the ADC via the DAC modules. A single ADC is configured to sense the phase A and phase B currents via two channels sequentially. Phase C current is not sensed as it can be derived from phase A and phase B currents. Three PWM writes simulate control of duty cycle of the three phase A, B and C voltages. Figure 2-1 represents the execution blocks in the control loop interrupt routine of the benchmark application. The control loop interrupt is triggered at a rate of 2 KHz and 1024 iterations of the control loop interrupt routine are executed before the application terminates.

In this block diagram, the dark gray blocks represent the peripheral accesses, the light gray blocks represent the control algorithms and the white blocks represent the code blocks that are not part of a real ACI motor control application but are used in the benchmark for simulating the behavior of the motor.

Figure 2-1 ACI Motor Benchmark Application Block Diagram