Fixed-speed motor systems have already been supplanted by variable-speed synchronous motors controlled by inverter-based drives.This has led to a significant boost in the energy efficiency of many pieces of industrial hardware, as the motor’s operation can better match the requirements of the application it is undertaking. This has only been the first stage of the evolutionary process however, as there is still a great deal of scope for improvement. The trapezoidal waveforms currently used for driving these motors are not actually that efficient when compared to what sinusoidal waveforms can achieve.
Sinusoidal motor driving will deliver faster, quieter and smoother action, allowing greater economy and user convenience to be witnessed. The construction of these waveforms is, of course, a more complex process, with considerable computational effort required. Vector control (also known as field oriented control) has become the accepted method for determining the voltage needed, based on the position of the rotor (as detected using magnetic sensor devices) or by monitoring the back EMF in each of the motor windings.
With the introduction of its proprietary Vector Engine (VE) technology, Toshiba has been able to embed the sophisticated vector control equations needed for generating sinusoidal motor drive waveforms into a dedicated hardware solution with customisable firmware. This means that the system microcontroller/microprocessor does not need to get involved, and its resources can be utilised elsewhere. This approach enables 70% faster execution times than conventional software-only vector control solutions can offer - thus permitting markedly faster rotor speeds to be supported and system power consumption to be substantially reduced.
To find out more about how Toshiba is changing the way in which motor control technology is implemented click here: