Chip-maker promises smaller, more reliable drives

International Rectifier claims that drives will become smaller and more reliable following its development of a new drive power management architecture that could halve the size of drive circuit boards and cut the number of parts needed by a quarter.

The architecture, dubbed Accelerator, is designed to fit between a drive`s microcontroller or DSP (digital signal processor) and the motor - either an AC induction machine or a brushless DC type.

The new architecture "delivers a speed range ten times wider than conventional designs, with significantly improved low-speed operation for AC inverter motor drives, by optimising dead time," explains David Tam, vice president for power integrated products at IR. "System performance is enhanced because the temperature-compensated current measurement technique enables torque precision as high as ±1%, versus ±2-3% in existing motor drives."

IR suggests that by simplifying drive power management, its system will allow drives-makers to concentrate on their control algorithms and HMIs.

IR has also developed a current-sensing IC with a built-in 1.5 ms over-current shutdown, that eliminates the need for external current-sensing protection circuits. It is said to simplify motor drive design in several ways, including eliminating bulky and slow opto or Hall effect sensors.