Variable-speed motors with electronic controls are becoming more common as manufacturers seek to better control motors and save energy. The demand is to incorporate more functions into the same or a smaller space at a lower cost.
The Intero family of motor-drive power modules from International Rectifier, El Segundo, Calif., integrates the power stage with an embedded driver board. The combination cuts design time and space while not sacrificing performance. It delivers programmable drive control, current sensing, isolation, and gate-driver and power-stage protection. The first device, the PIIPM50P12B004, is a 50-A, 1,200-V module that controls three-phase ac induction, brushless dc, and industrial servomotors up to 15 kW with an onboard programmable 40-Mips DSP.
The modules use International Rectifier NPT IGBTs. The positive-only gate-drive IGBTs eliminate the need for a negative bias power supply, lowering power losses and reducing trailing currents for lower losses at higher frequencies. This lets the embedded driver board mount directly on top of the power stage.
The smaller size means smaller heat sinks and EMI filters. Also, the power stage can be placed closer to the motor, reducing cable length and noise.