Building a three-phase PMSM sensorless FOC with Atmel

A three-phase Permanent Magnet Synchronous Motor (PMSM) sensorless FOC (Field Oriented Control) is typically found in a number of home appliances such as washing machines, dishwashers, dryers, refrigerators, air conditioners and pumps.

Key design considerations for a three-phase PMSM sensorless FOC include power efficient and acoustically quiet motor operation to meet governmental efficiency standards, low BOM cost and a compact, scalable FOC form factor.

“And that is precisely why Atmel’s XMEGA AVR (D or E series), coupled with our AVR1636 reference design, offers developers versatile integration capabilities along with comprehensive application support – facilitating FOC implementation that allows power efficient and acoustically quiet motor control application,” an Atmel engineering rep told Bits & Pieces.

“More specifically, there are three 16-bit timer/counters with up to four output compare or input capture channels, a high-resolution extension and advanced waveform extension (AWeX), an 8-channel Event System which allows peripherals to directly send, receive and react to synchronous or asynchronous events in a short, guaranteed response time.”

Additional integrated features include a feature-rich 300KS/s 12bit ADC with programmable gain amplifier up to 64x – with temperature, supply voltage and reference inputs; EEPROM for configuration parameters storage; two USART, one SPI and one I2C Serial Interfaces for system communication.

In terms of software and application support, Atmel offers AVR1636 reference design hardware; a firmware and PC configuration utility; AVR1610 pre-certified Class B library and design guide; Atmel Studio 6; Atmel Software Framework; Atmel Gallery; and free software libraries of production-ready source code.

Interested in learning more about building a three-phase PMSM sensorless FOC with Atmel’s AVR XMEGA? Be sure to check out some of the links below.

• Atmel ATXMEGA AVR Microcontroller Home Page
• Atmel AVR1636 Configurable Three Phase PMSM FOC Application Note
• Atmel AVR1610 Guide to IEC 60730 Class B Compliance with XMEGA
• Atmel Studio 6 Home Page
• Atmel Software Framework Home Page

Washing your clothes with Atmel MCUs

Washing machines. We all have them, or at the very least, use them to clean our clothes every so often. And yes, we’ve clearly come quite a long way since the very first electric washing machines were advertised in national newspapers during the early 1900’s.

Indeed, current-gen washing machines require support for motor controls, water level and temperature sensing, as well as an advanced UI (user interface) capable of withstanding harsh environments. And although one might not think it critical, standards-based, secure connectivity is also a must for appliances tapping into a home network.

As we’ve previously discussed on Bits & Pieces, Atmel’s extensive lineup of MCUs and touchscreen solutions are quite versatile and can be used for a number of applications, including washing machines.

First off, Atmel offers up a wide range of 8- and 32-bit microcontrollers that are dedicated to motor control – providing the appropriate support for BLDC motors, AC motors and switched reluctance motors.

Secondly, AVR 32-bit microcontrollers embed a digital signal processor (DSP) and a floating point unit (FPU) in select models, delivering the high performance required in advanced motor control solutions. Thirdly, many AVR microcontrollers include high-end PWM modules with dead-time insertion, fault management, synchronization with analog – making them a perfect choice for motor control.

In addition, AVR microcontrollers are offered in 105°C versions, as well as models up to 150°C, for a perfect match for washers with challenging temperature requirements. Meanwhile, Atmel provides an IEC 60730 Class B Library to support customers in the certification process, which dramatically speeds time to market. Plus, AVR 32-bit microcontrollers feature a multi-layer databus and DMA controller that make them a perfect fit for HMI applications where high bandwidth is required.

On the touch side, Atmel’s QTouch library offer designers the ability to easily add capacitive touch buttons, wheels and sliders – at no additional cost. In terms of reducing BOM, Atmel offers motor control and HMI touch in a single-chip, along with high power IOs that can directly drive LEDs and buzzers.

And last, but certainly not least, ZigBee PRO compatibility enables standards-compliant connectivity and smart metering, while node authentication capability supports smart meter infrastructure connections.

Interested in learning more? Additional information is available here.