Patent · US Expired

Active snubber for an inverter

US4849873A · kind A · utility

18Cited by
6References
18Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 5, 1987
Grant dateJul 18, 1989
Priority date
Expiry dateNov 5, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02M1/344
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Active snubber structure and method for use with an electronic power inverter to reduce turn off losses in electronic switches in the power inverter. The snubber structure includes a resistor and a capacitor connected in series with each other and in parallel with the load on the power inverter and parallel, inverse connected silicon controlled rectifiers connected in parallel with the resistor for selectively shorting the resistor. In the method of use of the active snubber structure, electrical energy is stored in the capacitor connected in parallel with the load during on time of the inverter and the resistor is shorted immediately prior to the off time of the inverter whereby the capacitor charges substantially to the value of the source of direct current electrical energy during the on time of the inverter and on shorting of the resistor during off time of the inverter, the voltage across the load changes slowly so that the switches of the inverter can transition from on through a resistor like turn off stage, to completely off before there is appreciable voltage across them.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.