GENEVA - STMicroelectronics has announced a new motor control kit, built around the recently-announced 32-bit STR750 microcontroller, designed to enable the rapid development of high-performance vector-control applications, using both permanent magnet synchronous motors (PMSM) and 3-phase AC induction motors, for cost-sensitive appliance, industrial, and HVAC markets. According to the company, the kit includes all necessary firmware and hardware - including a 24V DC permanent magnet motor for initial evaluation - to allow the user to be up and running within minutes, and to continue through to development of the target application.

Vector (or "field-oriented") control algorithms are widely used in high-performance drives, providing precise and responsive speed control, and guaranteeing optimized efficiency during transient operations, said STMicroelectronics. They also have the practical advantage of using the same framework to control both asynchronous and synchronous motors, a cost-saving feature for those dealing with a variety of applications and motor types. In addition, most sensor-less drive algorithms are based on field-orientation methodology, leading to further opportunities to reduce the drive cost.

The STR750-MCKIT is based on the integrated STR750 MCU, with ARM7TDMI CPU core, whose embedded peripheral set includes a PWM timer with three-phase motor-control features, synchronized with a high-speed analog-digital converter, designed to simplify the implementation of complex vector mode projects. Optimized and fully documented C firmware libraries for the control of both motor types are provided free in the kit, ensuring that most of the motor-control section of the application is already developed. Designing in the industry-standard ARM architecture saves development time compared to the use of a proprietary architecture.

The same hardware platform can be used for both PMSM and AC induction motors, operating at up to 48V; schematics are provided to minimize hardware design time. The kit allows real-time control and monitoring via a PC-based graphical user interface (GUI), or standalone operation using on-board push buttons and trimmers.

The STR750 family is said to be particularly suitable for motor control in appliances including air conditioners; in low and medium range industrial drives; in HVAC blowers and pumps; and in vending machines.

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Publication date:03/12/2007