International Rectifier Said It Achieved Technology Breakthrough In Power Electronics Systems For Automotive Alternators

Autoparts Report, Nov 19, 2002

International Rectifier (IR), El Segundo, Calif., said it began the production of the first Active Integrated Rectifier Regulator (AIRR) for automotive alternators. The AIRR has been designed by IR to meet Delphi Corp.'s specifications for the alternator of the recently introduced DaimlerChrysler Maybach luxury vehicle, the company said.

The AIRR can generate substantially higher power levels in a smaller outline than traditional passive rectifiers and alternator regulators, IR said.

This technology breakthrough opens the path for future power electronics development for next generation starter-alternators, the company said.

The AIRR combines a voltage regulator, which controls the output voltage of the alternator, with an active rectifier in one and the same module. The rectifier converts the alternating current generated by the alternator into the direct current required by the car electrical loads and battery. Simply put, active rectification is the replacement of passive diodes with active FETs to dramatically reduce power losses and increase fuel economy, IR said.

In the last decade, the automotive industry has seen a dramatic rise in demand for electrical energy, especially in light vehicles. More and more formerly purely mechanical functions are replaced by electrical and electronic systems to increase fuel mileage, reliability and safety. "The development in electrical power generation in vehicles has been struggling to keep up with electrical power demand. The transition to new technologies for power generation has so far been too challenging to allow a widespread adoption," says Peter Sommerfeld, Director of Engineering, Power Generation Systems, Automotive Business Unit, at International Rectifier.

"Active rectification has been discussed for a long time. We are the first to develop the technology to the point where it can be implemented in a production vehicle."

As the automotive electrical power requirements continue to increase from hundreds of watts today to several kilowatts in the near future, alternator technology itself will change, moving to belt-driven or crankshaft-mounted starter alternators, IR said. The new power generation architecture will require a new set of expertise for implementation of the power electronics sub-system, it added.