JAJU802A January 2022 – October 2022
Today’s HVAC applications must meet a growing list of demands on low cost, smaller size, more comfort, more powerful and high energy efficiency. It is well known that PMSM is becoming increasingly popular over induction motor in HVAC applications. This reference design provides a true single chip solution for dual motor drives, including the front-end interleaved boost PFC. Implementation of controlling two motors using field oriented control (FOC) without position sensor, and an interleaved boost PFC using a single controller is illustrated. The overall system helps users to reduce the number of critical components in the bill of materials, reduce the size of bulky passive components, improve efficiency, minimize input-current harmonic content, maximize power factor, precisely regulate the DC bus, and save development time. This reference design based on TMS320F28002x or TMS320F28003x real-time controller family makes it easy to get started on an HVAC system outdoor unit controller design.
The ability to control multiple motors not only reduces system cost but also improves overall power efficiency and performance. For applications that operate dual motors, having both motors controlled by a single MCU enables the controller to coordinate how quickly it ramps one motor up relative to the speed of the other motor. And because both motors draw from the same current source, the PFC implementation can be coordinated as well for better results.
The reference design provides flexibility to support many different types of air conditioner systems, the hardware capabilities for more optional features beside motor drive and PFC like serial communication with indoor unit, stepper motor drive for electronic expansion valve, and temperature sensors for HVAC system control.