Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Controls/MCUs

Motor control devt kit eases vector drive design

Posted: 15 Mar 2007 ?? ?Print Version ?Bookmark and Share

Keywords:flash memory? motor control? field-oriented control? ST? vector control?

Motor control development kit from ST

STMicroelectronics has announced a new motor control kit that enables the rapid development of high-performance vector-control applications, using both permanent magnet synchronous motors (PMSM) and three-phase AC induction motors, for cost-sensitive appliance, industrial and HVAC markets.

The kit have all the necessary firmware and hardwareincluding a 24Vdc permanent magnet motor for initial evaluationto allow the user to be up and running within minutes, and to continue through to development of the target application.

FOC algorithms
Vector or field-oriented control algorithms are widely used in high-performance drives, providing precise and responsive speed control and ensuring optimized efficiency during transient operations. They also have the practical advantage of using the same framework to control both asynchronous and synchronous motors, a cost-saving feature for development teams dealing with different applications and motor types. Moreover, most sensorless drive algorithms are based on field-orientation methodology, increasing opportunities to reduce the drive cost.

The STR750-MCKIT is based on the highly integrated STR750 MCU, with ARM7TDMI CPU core, whose rich embedded peripheral set includes a PWM timer with three-phase motor-control features, synchronized with a high-speed ADC, designed to simplify the implementation of complex vector mode projects. 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 GUI, or standalone operation using on-board push buttons and trimmers. Segger/IAR J-Link emulation is included, and the flash programming and real-time debugging capability allows the same hardware and firmware platform to be used from evaluation through to an advanced stage of development, removing the need for the user to build a platform before starting work on the target system. A debugger and programmer are also included.

54MIPS operation
The STR750 family is the first general-purpose ARM7 flash MCU to support full-spec, 54MIPS (at 60MHz) operation at both 3.3V and 5V, providing maximum flexibility in electrically noisy environments without additional costs. Aside from motor-friendly timer and ADC systems, its rich peripheral set includes innovative features such as a backup clock that operates if the main clock fails and a fast startup capability that allows it to begin executing code in only 55?s, instead of typically 1ms required by MCUs using a quartz crystal. It also features an automatic wake up (AWU) capability that removes the need for an external input to wake from low power stop or standby modes.

Its advanced timers and security features make the STR750 family suitable for motor control, in appliances such as washing machines, dishwashers and air conditioners; in low and medium range industrial drives and electric vehicles; in HVAC blowers and pumps; and in vending machines and office automation. Serial communications include up to three high-speed (2Mbps) UARTs with support for the LIN protocol, and a serial memory interface for glueless connection to external serial flash memory.

The family comprises some 30 derivatives, embedding between 64KByte and 256KByte of flash memory, plus an additional 16KByte bank of Read-While-Write flash for EEPROM emulation. Up to eight communication peripherals are available, including USB and CAN, as well as a 4-channel DMA controller that significantly reduces CPU loading, and a fast 10-bit ADC. Some members of the family are specified over an extended temperature range of -40C to +105C.

The STR750-MCKIT is available at $895, including a 24Vdc PMSM. An AC induction motor for use with the evaluation board can be ordered separately.

Article Comments - Motor control devt kit eases vector ...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top