Adaptive Power Control for Energy Harvesting

Abstract

Advances in the arts are disclosed with novel methods and circuit systems for controlling power in an energy harvesting system. Techniques and related systems for controlling power output of an energy harvesting device provide for monitoring at least one power parameter at a power source and monitoring at least one power parameter at a load such as a storage medium. The power source output is adjusted in order to optimize energy harvesting and/or storage based on real-time performance parameters.

1 . A method for controlling power in an energy harvesting system comprising the steps of:
 monitoring at least one power parameter at a power source;   monitoring at least one corresponding power parameter at a load operably coupled to the power source;   responsive to a lower monitored power source parameter threshold, increasing power source output; and   responsive to an upper monitored power source parameter threshold, decreasing power source output.   
     
     
         2 . The method according to  claim 1  wherein the power source charges a storage battery. 
     
     
         3 . The method according to  claim 1  wherein the power source charges a storage capacitor. 
     
     
         4 . The method according to  claim 1  wherein at least one power parameter comprises voltage. 
     
     
         5 . The method according to  claim 1  wherein at least one power parameter comprises current. 
     
     
         6 . The method according to  claim 1  wherein the responsive change to the power source output comprises changing the voltage to maximize power output. 
     
     
         7 . The method according to  claim 1  wherein the responsive change to the power source output comprises changing the current to maximize power output. 
     
     
         8 . A method according to  claim 1  wherein the power source consists of one or more selections from the group of sources: photovoltaic; electromechanical; thermoelectric; electrochemical; piezoelectric. 
     
     
         9 . A method for controlling power in an energy harvesting system comprising the steps of:
 monitoring at least one power parameter at a variable power source;   monitoring at least one corresponding power parameter at a storage medium operably coupled to the variable power source;   responsive to a lower monitored power source parameter threshold, increasing variable power source output current;   responsive to an upper monitored power source parameter threshold, decreasing variable power source output current; and   thereby maintaining maximum power point tracking in the energy harvesting system.   
     
     
         10 . An energy harvesting system comprising:
 at least one power source;   at least one power source monitor for monitoring a power parameter at a power source;   at least one load operably coupled to the power source;   a load monitor for monitoring a power parameter at a load; and   a control module for using the monitored parameters to control power supplied to the load by the power source.   
     
     
         11 . An energy harvesting system according to  claim 10  further comprising a regulator module operably coupled between a power source and a load for regulating power source output voltage for maximum power output. 
     
     
         12 . An energy harvesting system according to  claim 10  further comprising a regulator module operably coupled between a power source and a load for regulating power source output current for maximum power output. 
     
     
         13 . An energy harvesting system according to  claim 10  wherein the power source consists of one or more selections from the group: photovoltaic; electromechanical; thermoelectric; electrochemical; piezoelectric. 
     
     
         14 . An energy harvesting system according to  claim 10  wherein the load comprises a storage battery. 
     
     
         15 . An energy harvesting system according to  claim 10  wherein the load comprises a storage capacitor. 
     
     
         16 . A control circuit for maximizing power delivered to a load, comprising:
 a power source for producing a current and a voltage;   a load for receiving current and voltage from the power source;   monitoring circuitry for monitoring the relative power levels of the source and the load;   controlling circuitry for adjusting the power source current and voltage in response to the monitored power levels of the source and the load such that the power output of the source is maintained at an optimum level.   
     
     
         17 . A control circuit according to  claim 16  wherein the controlling circuitry is configured for adjusting the power source output current limit in order to maximize power delivered to the load. 
     
     
         18 . A control circuit according to  claim 16  wherein the controlling circuitry is configured for adjusting the power delivered to the load in order to maximize power produced by the source. 
     
     
         19 . A control circuit according to  claim 16  wherein the controlling circuitry further comprises an integrator for monitoring input voltage and changing an output current of a regulator in order to maximize power at the source and power at the load. 
     
     
         20 . A control circuit according to  claim 16  further comprising one or more power source selected from the group: photovoltaic; electromechanical; thermoelectric; electrochemical; piezoelectric. 
     
     
         21 . A control circuit according to  claim 16  wherein the load further comprises a storage battery. 
     
     
         22 . A control circuit according to  claim 16  wherein the load further comprises a storage capacitor.