Overview
This reference design is a 3-phase brushless DC (BLDC) motor sensorless drive for fans, pumps and compressors based on the low-cost NXP® 56F801x digital signal controllers (DSCs).
- The concept is a closed-loop speed-controlled BLDC drive with no need for position or speed sensors
- AIt serves as a reference design for a BLDC motor sensorless control system, ideal for fan, pump and compressor applications
- Power stages used by the application are designed for 12V DC line voltage and 3Aor 8A output current
- The reference manual provides a detailed description of the application, including design of the hardware and the software
Features
- 3-phase brushless DC motor sensorless drive
- Designed to fit into fan, pump and compressor applications
- Uses 56F8013 32 MIPS Digital Signal Controller
- Available for two power stages and two motors
- Input power supply voltage +12 VDC for power stages
- Control techniques incorporate:
- Sensorless, trapezoidal control of 3-phase BLDC motor with back-EMF sensing
- ADC zero crossing sensing for sensorless control
- Closed-loop speed control using PI controller
- Adjustable DC-bus current limitation PI controller
- Motoring mode
- Both directions of rotation
- Speed range: 200-2000 and 800-8000 RPM (depending on the motor used)
- Manual interface (RUN/STOP switch, UP/DOWN pushbuttons)
- FreeMaster interface for monitoring, controlling and tuning
- Fault protection (DC-bus over-current, DC-bus under-voltage, DC-bus over-voltage)
- Automatic calibration of phase back-EMF measurements
- 20 kHz PWM switching frequency
- Easy to tune for different power stages and motors.
