Accession Number : ADD009086

Title :   Power Frequency Converter.

Descriptive Note : Patent,


Personal Author(s) : Brooks,James L ; Bowers,James C ; Nienhaus,Harry A

Report Date : 06 Oct 1981

Pagination or Media Count : 8

Abstract : A power converter is described which provides precise waveshape regulation. An input power waveform (three-phase or single phase power) is rectified and modulated to form a chopped waveform within an envelope defined by the rectified input waveform. The modulation is removed by passing the chopped signal through a low-pass filter. The output of the low-pass filter, which is equal to the instantaneous value of the chopped waveform envelope times the instantaneous value of the duty cycle of the chopped waveform, is converted to a complete sine wave output voltage in a power inverter. The output of the power inverter is sampled and compared with a low-power reference waveform in a differential amplifier. The output of the differential amplifier is phase compensated for the effects of the low-pass filter and applied as an error signal to a pulse-width-modulated oscillator to adjust the duty cycle of the chopped waveform so that the sine wave output voltage follows the reference waveform. (Author)

Descriptors :   *Patents, *Frequency converters, *Inverter circuits, *Power equipment, *Rectifiers, Alternating current, Sine waves, Superlow frequency, Low pass filters, Low power, Signals, Input, Errors, Amplifiers, Modulation, Jobs, Filters, Voltage, Cycles, Power, Converters, Waveforms

Subject Categories : Electrical and Electronic Equipment
      Electric Power Production and Distribution

Distribution Statement : APPROVED FOR PUBLIC RELEASE