High Efficient Drive Technologies for Advanced Air-Conditioner Inverter System

摘要

In Japan, the energy-saving index of air conditioners changed from the coefficient of performance at the rated operation and to the annual performance factor, which is closer to the condition of actual use in Japan. Under this circumstance, efficiency improvement at low load operation is required for the inverter system. In response to this requirement, we have applied a MOSFET with a super junction structure (SJ-MOSFET) as a switching device for the compressor motor, and developed a new driving method named Smart PRE Switching. By this technology, we can overcome the disadvantage of MOSFET characteristic of a super junction structure and obtained high operating efficiency by 2-4% at low load operation mode, compared to the conventional IGBT inverter system.