DC-TO-400HZ INVERTER

NDT TECHNOLOGIES, INC. HAS RECENTLY DEMONSTRATED THE FEASIBILITY OF A SIMPLE, LIGHTWEIGHT, HIGH-EFFICIENCY POWER CONDITIONING MODULE. THE MODULE IS VERY VERSATILE AND CAN BE USED AS A BUILDING BLOCK FOR A WIDE VARIETY OF APPLICATIONS SUCH AS: FOUR-QUADRANT BI-DIRECTIONAL DC-AC INVERSION, LINE VOLTAGE REGULATION, UNINTERRUPTIBLE POWER SUPPLIES, ACTIVE POWER FILTERING, DC ISOLATION, POWER FACTORCOMPENSATION, AND FOUR-QUADRANT BI-DIRECTIONAL VOLTAGE/FREQUENCY CONVERSION. FURTHERMORE, IN MANY CASES, USE OF THE MODULE CAN ELIMINATE HEAVY AND EXPENSIVE LOW-FREQUENCY TRANSFORMERS AND OTHER INDUCTIVE SYSTEM COMPONENTS. IN PARTICULAR, THIS NEW MODULE APPEARS WELL-SUITED AS A DC-TO-400HZ INVERTER. THE PRESENT PROTOTYPE USES CLAMP-DIODE SWITCHING, WHICH, DUE TO THE REVERSE REDOVERY CHARACTERISTICS OF DIODES, CAUSES CERTAIN PROBLEMS. THESE PROBLEMS INCLUDE EMI/RFI, HIGH SWITCHING STRESSES AND UNNECESSARILY HIGH SWITCHING LOSSES. TO REMEDY THESE SHORTCOMINGS, IT IS PROPOSED TO REPLACE THE PRESENT CLAMP-DIODE SWITCHING APPROACH WITH A QUASI-RESONAMT SWITCHING SCHEME. QUASI-RESONANT SWITCHING ALLOWS SWITCHING FREQUENCIES UP TO THE MEGA-HERTZ RANGE. ITOFFERS MANY ADVANTAGES, SUCH AS: LOW EMI/RFI, LOW SWITCHING STRESSES AND SWITCHING LOSSES, EXTREMELY HIGH POWER DENSITIES AND, THEREFORE, EXTREMELY LIGHTWEIGHT AND COMPACT POWER CONDITIONING MODULES.