David C Caldwell

US Patent:

54932041, Feb 20, 1996

Filed:

Aug 4, 1994

Appl. No.:

8/285840

Inventors:

David J. Caldwell - Hermosa Beach CA

Assignee:

The Aerospace Corporation - El Segundo CA

International Classification:

G05F 500

US Classification:

323299

Abstract:

A peak power tracker apparatus is used for controlling the negative impedance of converter for transferring maximum power from a solar array source to a battery and load typically used in space vehicles, by capacitive differentiation sensing the solar array source voltage for sensing the peak power point at which the source voltage first begins to become unstable and collapses, and then providing a step down control signal which controls a current mode pulse width modulator to control the converter to vary the negative impedance into the solar array then reserving back to a stable point at which the tracker then provide a linear ramp signal to the modulator to control the converter to drive the source voltage again to the peak power point, so as to alternate the feedback loop and source voltage between a stable point and the peak power point so as to transfer maximum power while preventing the source voltage to pass through an unstable point for discontinuous but stable operation at peak power transfer which is independent of array performance and is adaptable to a wide range of power sources.