'Third era' for drives could cut motor energy use by 40%
An American technology firm claims to have developed software that can be added to almost any AC drive to cut the energy consumed by the motor up to 40%, as well as improving the motor's performance. AC Kinetics (ACK), based in New York State, contends that its technology represents a “third era” for variable speed drives, following V/f controls in 1960s and vector controls in the 1980s.
“We have developed several algorithms for electric motor control that reduce energy consumption by 10–40%, while simultaneously improving motor performance,” explains ACK president, Dr Neil Singer. “Our technology also enables motors to run cooler, and therefore last longer.” The energy savings are in addition to those normally achieved by using VSDs.
Dr Singer says that AC Kinetics is already in talks with VSD manufacturers about testing and possibly adopting the new technology. He predicts that the first drives implementing the new algorithms could go on sale before the end of 2013.
The algorithms run in real time on standard drive hardware, and can replace the control algorithms on most existing AC drives. The initial version of the software needs to be able to measure the motor current, which may limit its implementation on some drives.
According to Singer (above), the ACK software does not need a lot of memory or computing power to operate. “We did a lot of work to get it to work with existing microcontrollers,” he says. For example, it will run on TI’s Piccolo devices that are used widely in motor controls.
ACK is not revealing precisely how its architecture works, but says that it has been designed “from the ground up to realise rapid dynamic performance, while minimising losses in the motor”. The technology integrates real-world, non-linear motor phenomena, including core losses, non-linear inductances, and saturation, in the motor and inverter.