Case of study
Sensorless Brushless DC Reference Software for White Goods
With Infineon XC16x processor
Brushless DC in the White Goods and Appliances
Targeted primarily to the design and development in the white goods industry, this BLDC reference software kit is meant to give the customer a ready to use platform: it is conceived to be used upon an Infineon Motor Control StarterKit, an hardware platform enabled to drive either Brushless, V/F Induction or Field Oriented Control software modules.
The white goods & appliances market is widely deploying electronically-controlled motors to obtain better overall performance while maintaining competitive prices: it is certainly true that the brushless, commutated motor is more expensive when compared to its traditional brushed or induction counterpart; it requires dedicated control circuitry and a power conversion stage.
However, the global result is an increase in the appliance’s thermal efficiency, thus leading to lower overall costs.
Brushless Application Software
The BLDC reference software is intended to give the customer a ready to use platform: it is conceived to be used upon an Infineon Motor Control StarterKit ASM750 (265 V AC maximal voltage supply), enabling either Brushless, V/F Induction or Field Oriented Control software modules.
A three phases, three poles brushless DC motor has been used in the demo.
- Startup Procedure and positioning (phasing)
- Single shunt current acquisition
- Hall Sensor based position feedback
- Back-EMF Sensorless position detection
- Matlab Modeling and simulation tools
- Diagnostic/Debug software
In order to control the torque and speed of a BLDC-brushless DC one needs to know the rotor position, the current in each phase, and the speed. With sensorless approach the position is determined through the evaluation of zero crossing of back EMF, which permits to use motors without Hall position sensors. By using a single shunt placed in the DC line along with the position information, it is possible to determine the instant phase current, while the speed is evaluated using the zero crossing frequency. Learn more in the Brushless DC Application Note.
The BLDC Application software is based on the XC16x 16 bit Infineon microcontroller family.
See more at http://www.infineon.com/