US 5,923,100 AGranted

Apparatus for controlling a solar array power system

AssigneeLockheed Martin Corporation

InventorsFrederick E. Lukens, Robert L. Moser

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Abstract

A system for controlling power supplied by a solar array panel to one of either a load or a battery for optimal power consumption is disclosed. The solar array power control system of the present invention includes a power stage for directing the solar array to discharge an appropriate amount of current, a signal conditioner for receiving and conditioning voltage and current signals from the solar array and determining the signs of the time derivatives of solar array voltage and power, a processor for evaluating the signs of the time derivatives of solar array power voltage and for directing operation of either a battery current control mode or a peak power tracking mode and a high gain amplifier for directing an appropriate voltage to the power stage according to the operating mode. The signal conditioner, processor and high gain amplifier cooperate to determine whether the solar array is capable of supplying the power demanded by at least one of the battery and the load. When it has been determined that the required power level to be supplied from the solar array is within the capability of the solar array, the system commands the solar array to discharge the exact power demanded. In times when the solar array is not capable of completely satisfying the required power level, the system commands the solar array to discharge the maximum power available under the present conditions.

Claims36

Dependent claims

A satellite comprising:

means for converting solar energy into electric energy, wherein voltage and current signals output by said means for converting can be characterized by a power-voltage curve having a peak power point with zero slope, a first region to the left of said peak power point with a positive slope, and a second region to the right of said peak power point with a negative slope;
battery means for storing electric energy provided by said means for converting;
load means for receiving electric energy from at least one of said means for converting and said battery means, said battery means being capable of providing electric power to said load means, and for using said electric power to perform satellite tasks;
and
means for controlling application of electric energy produced by said means for converting to at least one of said battery means, for charging said battery means, and said load means, for performing said satellite task, wherein said means for controlling includes means for peak power tracking of an electric power signal supplied by said means for converting about said peak power point in only one of a battery current control mode, wherein said power output from said means for converting is in said second region, and a peak power tracker mode, wherein said power output from said means for converting is in said first region, wherein said means for peak power tracking includes means for receiving and measuring the voltage and current signals from the means for converting solar energy which additionally generates sign of the times derivatives for power and voltage output from the means for converting solar energy in order to determine an instantaneous operating power region on said power-voltage curve.

2 more elements

A system for controlling electrical energy provided by a solar array to at least one of a battery and a load member, wherein power output by the solar array is characterized by a power voltage curve having a peak power point with zero slope, a first region to the left of the peak power point having a positive slope, and a second region to the right of the peak power point having a negative slope, said system comprising:

means for receiving instantaneous inputs indicative of amounts of voltage and current being output by the solar array, current available from the battery and current needed for charging the battery;
means for outputting a control signal indicative of current to be supplied from the solar array to at least one of the battery and the load member;
and
means for processing said inputs to produce said control signal, wherein said means for processing includes means for peak power tracking of electric power provided by the solar array in only one of a battery current control mode, wherein the power output from the solar array is in the second region, and a peak power tracker mode, wherein the power output from the solar array is in the first region, wherein said means for peak power tracking comprises means for receiving and measuring the voltage and current output by the solar array and additionally generating a sign of the times derivatives of electric power and voltage output by the solar array wherein the sign of the times derivatives are used to determine an instantaneous operating power region on said power voltage curve.

1 more element

Dependencies are inferred from the claim text.