Allocation of power sources in an air conditioning system

Abstract

A method of allocating power sources in an air conditioning system includes determining a load demand of the air conditioning system; determining whether a demand response (DR) event or a time-of-use (ToU) high rate is occurring; in response to the DR event or ToU high rate not occurring, charging an energy storage device to an upper voltage, the charging performed at a predefined charging power level during a predefined charging period; in response to the DR event or ToU high rate occurring, determining an allocation of power sources to satisfy the load demand and discharging the energy storage device at a predefined discharging power level and a predefined discharging time period until the energy storage device reaches a lower voltage level or the DR event or ToU high rate is finished.

What is claimed is: 
     
         1 . A method of allocating power sources in an air conditioning system, the method comprising:
 determining a load demand of the air conditioning system;   determining whether a demand response (DR) event or a time-of-use (ToU) high rate is occurring;   in response to the DR event or ToU high rate not occurring, charging an energy storage device to an upper voltage, the charging performed at a predefined charging power level during a predefined charging period;   in response to the DR event or ToU high rate occurring, determining an allocation of power sources to satisfy the load demand and discharging the energy storage device at a predefined discharging power level and a predefined discharging time period until the energy storage device reaches a lower voltage level or the DR event or ToU high rate is finished.   
     
     
         2 . The method of  claim 1 , wherein the power sources include the energy storage device, an AC power grid and one or more auxiliary power sources. 
     
     
         3 . The method of  claim 2 , wherein the one or more auxiliary power sources include a DC power source. 
     
     
         4 . The method of  claim 2 , wherein the one or more auxiliary power sources include a photovoltaic source. 
     
     
         5 . The method of  claim 1 , wherein the load demand of the air conditioning system is predicted based on real-time or predicted weather conditions, including outdoor air temperature (OAT) and humidity. 
     
     
         6 . The method of  claim 1 , wherein the load demand of the air conditioning system is predicted based on one or more of past performance data, a set point, occupancy of a building conditioned by the air conditioning system, user preferences and a coefficient of performance of the air conditioning system. 
     
     
         7 . The method of  claim 1 , wherein the power sources include the energy storage device, an AC power grid and one or more auxiliary power sources;
 wherein determining the allocation of power sources to satisfy the load demand includes prioritizing one of the energy storage device, the AC power grid and the one or more auxiliary power sources to satisfy the load demand.   
     
     
         8 . The method of  claim 7 , wherein the one or more auxiliary power sources are prioritized over the AC power grid and the energy storage device to satisfy the load demand. 
     
     
         9 . The method of  claim 8 , wherein the one or more auxiliary power sources include a photovoltaic source. 
     
     
         10 . The method of  claim 7 , wherein the one or more auxiliary power sources are prioritized in response to a cost of electricity from the AC power grid, electricity production cost derived from a cost to charge the energy storage device and a thermal energy cost derived from coefficient of performance date of the air conditioning system. 
     
     
         11 . A method of allocating power sources in an air conditioning system, the method comprising:
 determining a load demand of the air conditioning system;   determining whether a utility event is occurring;   in response to the utility event not occurring, charging an energy storage device to an upper voltage, the charging performed at a predefined charging power level during a predefined charging period;   in response to the utility event occurring, determining an allocation of power sources to satisfy the load demand and discharging the energy storage device at a predefined discharging power level and a predefined discharging time period until the energy storage device reaches a lower voltage level or the utility event is finished.   
     
     
         12 . A system for allocating power sources in an air conditioning system, the system comprising:
 a first unit having a compressor and at least one fan;   a second unit in fluidly coupled to the first unit;   a controller in communication with the first unit, the controller configured to execute operations including:
 determining a load demand of the air conditioning system; 
 determining whether a demand response (DR) event or a time-of-use (ToU) high rate is occurring; 
 in response to the DR event or ToU high rate not occurring, charging an energy storage device to an upper voltage, the charging performed at a predefined charging power level during a predefined charging period; 
 in response to the DR event or ToU high rate occurring, determining an allocation of power sources to satisfy the load demand and discharging the energy storage device at a predefined discharging power level and a predefined discharging time period until the energy storage device reaches a lower voltage level or the DR event or ToU high rate is finished. 
   
     
     
         13 . A system for allocating power sources in an air conditioning system, the system comprising:
 a first unit having a compressor and at least one fan;   a second unit in fluidly coupled to the first unit;   a controller in communication with the first unit, the controller configured to execute operations including:
 determining a load demand of the air conditioning system; 
 determining whether a utility event is occurring; 
 in response to the utility event not occurring, charging an energy storage device to an upper voltage, the charging performed at a predefined charging power level during a predefined charging period; 
 in response to the utility event occurring, determining an allocation of power sources to satisfy the load demand and discharging the energy storage device at a predefined discharging power level and a predefined discharging time period until the energy storage device reaches a lower voltage level or the utility event is finished. 
   
     
     
         14 . A computer program embodied on a non-transitory computer-readable storage medium, the computer program including instructions for causing a processor to implement a process for allocating power sources in an air conditioning system, the process comprising:
 determining a load demand of the air conditioning system;   determining whether a demand response (DR) event or a time-of-use (ToU) high rate is occurring;   in response to the DR event or ToU high rate not occurring, charging an energy storage device to an upper voltage, the charging performed at a predefined charging power level during a predefined charging period;   in response to the DR event or ToU high rate occurring, determining an allocation of power sources to satisfy the load demand and discharging the energy storage device at a predefined discharging power level and a predefined discharging time period until the energy storage device reaches a lower voltage level or the DR event or ToU high rate is finished.   
     
     
         15 . A computer program embodied on a non-transitory computer-readable storage medium, the computer program including instructions for causing a processor to implement a process for allocating power sources in an air conditioning system, the process comprising:
 determining a load demand of the air conditioning system;   determining whether a utility event is occurring;   in response to the utility event not occurring, charging an energy storage device to an upper voltage, the charging performed at a predefined charging power level during a predefined charging period;   in response to the utility event occurring, determining an allocation of power sources to satisfy the load demand and discharging the energy storage device at a predefined discharging power level and a predefined discharging time period until the energy storage device reaches a lower voltage level or the utility event is finished.