Objectives learned in this build level:

• Evaluate the open-loop operation of the system
• Use the HAL object to set up the MCU controller and initialize the inverter
• Verify the PWM and ADC driver modules
• Become familiar with the operation of CCS

Because this system is running with open-loop control, the ADC measured values are only used for instrumentation purposes in this build level. Only bias power supply for MCU controller and gate drivers is used in this build level. The high-voltage AC and DC power supply are not implemented on the inverter.

In this build level, the board is executed in open-loop fashion with a fixed duty cycle. The duty cycles are set to 50% for the motor. This build level verifies the sensing of feedback values from the power stage and also operation of the PWM gate driver and makes sure there are no hardware issues. Additionally calibration of input and output voltage sensing can be performed in this build level. The software flow for this build level is shown in Figure 4-1.

Figure 4-1 Control Software Block Diagram: Build Level 1 – Offset Validation