AN1953 Application note introduces how to use the ST7MC microcontroller to implement Power Factor Correction (PFC) inside a motor control application.
The document describes an application where the ST7MC microcontroller manages a boost stage to achieve Power Factor Correction (PFC) in transition mode. This setup allows the microcontroller's resources to be used for motor control functions for induction and permanent magnet synchronous motors. The system operates with a fixed ON-time and variable frequency, suitable for power below 600W.
To implement this, the text details modifications required on the ST7MC Starter Kit hardware, including replacing specific components like capacitors and resistors to handle a bus voltage of 400-500V. It also outlines the connection between the modified starter kit and an external "Add On" power board, specifying the wiring for PWM signals and zero-crossing detection.
| Power rating | below 600W |
|---|---|
| Output voltage target | 400V |
| ADC sampling method | average of eight ADC conversions |
| Interrupt service routine frequency | every 1ms |
| PWM adjustment interval | Each 20ms |
| Bus voltage range | 400-500 Volt |
The aim is to give an example of how to use the ST7MC microcontroller to implement the Power Factor Correction (PFC) inside a motor control application.
The hardware consists of the ST7MC Starter Kit plus an additional external power board called "Add On".
Extra information about motor control related routines can be found in application note AN1904.