Controlling a dispatch operation of an energy storage system

Abstract

Systems and methods of controlling a dispatch operation of an energy storage system are provided. In particular, a degradation value of a present dispatch state of an energy storage system can be determined. The present dispatch state can specify one or more energy storage units presently coupled to the system. The degradation value can be determined based at least in part on one or more operating parameters, such as temperature, open circuit voltage, charge or discharge current, and/or contactor life. The degradation value can then be compared against one or more degradation values associated with one or more candidate dispatch states. A dispatch state can then be selected based on the comparison. One or more energy storage units can be selectively coupled to the energy storage system based at least in part on the selected dispatch state.

What is claimed is: 
     
         1 . A method of actively controlling a dispatch operation of an energy storage system, the method comprising:
 receiving, by one or more control devices, data indicative of a present dispatch state associated with an energy storage system, the energy storage system comprising a plurality of energy storage units coupled in parallel, the present dispatch state specifying the energy storage units presently coupled to the system;   identifying, by the one or more control devices, one or more candidate dispatch states associated with the energy storage system, each of the one or more candidate dispatch states being different from the present dispatch state;   selecting, by the one or more control devices, at least one of the one or more candidate dispatch states as a selected dispatch state based at least in part on a performance model, the performance model modeling the performance of the one or more candidate dispatch states as a function of one or more operating parameters; and   controlling, by the one or more control devices, operation of the energy storage system based at least in part on the selected dispatch state.   
     
     
         2 . The method of  claim 1 , wherein the operating parameters are measured operating parameters. 
     
     
         3 . The method of  claim 1 , wherein selecting, by the one or more control devices, the candidate dispatch state as a selected dispatch state based at least in part on a performance model, comprises:
 determining, by the one or more control devices, a degradation value for each of the one or more candidate dispatch states based on the performance model; and   selecting, by the one or more control devices, the candidate dispatch state as the selected dispatch state based at least in part on the degradation value.   
     
     
         4 . The method of  claim 3 , wherein identifying, by the one or more control devices, the selected dispatch state based at least in part on the degradation value comprises performing an optimization routine based at least in part on the performance model. 
     
     
         5 . The method of  claim 4 , wherein the optimization routine comprises:
 during each of a plurality of time periods, identifying, by the one or more control devices, a candidate dispatch state by incrementally adjusting a number of energy storage units to be coupled to the system; and   for each candidate dispatch state, determining, by the one or more control devices, a degradation value for the candidate dispatch state associated with the incremental adjustment.   
     
     
         6 . The method of  claim 5 , wherein incrementally adjusting a number of energy storage units to be coupled to the system comprises decreasing or increasing a number of energy storage units to be coupled to the system. 
     
     
         7 . The method of  claim 1 , wherein the one or more operating parameters comprise at least one of an open circuit voltage, a temperature, a current or a contactor life associated with the respective energy storage units. 
     
     
         8 . The method of  claim 1 , wherein the one or more candidate dispatch states are identified at least in part from a lookup table associated with the energy storage system. 
     
     
         9 . The method of  claim 1 , wherein the performance model takes into account one or more constraints. 
     
     
         10 . The method of  claim 10 , wherein the one or more constraints comprise at least one of the power commitment, a power, a current, a voltage characteristic, or a temperature associated with the energy storage system. 
     
     
         11 . The method of  claim 1 , wherein controlling, by the one or more control devices, operation of the energy storage system based at least in part on the selected dispatch state comprises coupling one or more energy storage devices to the energy storage system in accordance with the selected dispatch state. 
     
     
         12 . An energy storage system comprising:
 a plurality of energy storage units coupled in parallel; and   a system controller communicatively coupled to a plurality of contactors used to selectively couple the plurality of energy storage units to the energy storage system, the system controller comprising at least one processor and a non-transitory computer-readable medium storing instructions that, when executed by the at least one processor, cause the system controller to perform operations, the operations comprising:   receiving data indicative of a present dispatch state associated with the energy storage system, the present dispatch state specifying the energy storage units presently coupled to the system;   identifying one or more candidate dispatch states associated with the energy storage system, each of the one or more candidate dispatch state being different from the present dispatch state;   selecting at least one of the one or more candidate dispatch states as a selected dispatch state based at least in part on a performance model, the performance model modeling the performance of the one or more candidate dispatch states as a function of one or more measured operating parameters; and   controlling operation of the energy storage system based at least in part on the selected dispatch state.   
     
     
         13 . The energy storage system of  claim 12 , wherein selecting the candidate dispatch state as a selected dispatch state based at least in part on a performance model comprises:
 determining a degradation value for each of the one or more candidate dispatch states; and   selecting the candidate dispatch state as the selected dispatch state based at least in part on the degradation value.   
     
     
         14 . The energy storage system of  claim 12 , wherein identifying the selected dispatch state based at least in part on the degradation value comprises performing an optimization routine based at least in part on the performance model. 
     
     
         15 . The energy storage system of  claim 14 , wherein the optimization routine comprises:
 during each of a plurality of time periods, identifying a candidate dispatch state by incrementally adjusting a number of energy storage units to be coupled to the system; and   for each candidate dispatch state, determining a degradation value for the candidate dispatch state associated with the incremental adjustment.   
     
     
         16 . The energy storage system of  claim 15 , wherein the optimization routine further comprises:
 during each time period of the plurality of time periods, comparing the degradation value associated with the candidate dispatch state identified in the present time period with the degradation value associated with the candidate dispatch state identified in the previous time period; and   selecting the present candidate dispatch state as a selected dispatch state when the degradation value associated with the candidate dispatch state identified in the present time period is less than the degradation value associated with the candidate dispatch state identified in the previous time period.   
     
     
         17 . A system controller for controlling one or more energy storage units in an energy storage system, the system controller comprising at least one processor and a non-transitory computer-readable medium storing instructions that, when executed by the at least one processor, cause the system controller to perform operations, the operations comprising:
 receiving data indicative of a present dispatch state associated with an energy storage system, the energy storage system comprising a plurality of energy storage units coupled in parallel, the present dispatch state specifying the energy storage units presently coupled to the system;   identifying one or more candidate dispatch states associated with the energy storage system, each of the one or more candidate dispatch state being different from the present dispatch state;   selecting at least one of the one or more candidate dispatch states as a selected dispatch state based at least in part on a performance model, the performance model modeling the performance of the one or more candidate dispatch states as a function of one or more measured operating parameters; and   controlling operation of the energy storage system based at least in part on the selected dispatch state.   
     
     
         18 . The system controller of  claim 17 , wherein selecting the candidate dispatch state as a selected dispatch state based at least in part on a performance model comprises:
 determining a degradation value for each of the one or more candidate dispatch states; and   selecting the candidate dispatch state as the selected dispatch state based at least in part on the degradation value.   
     
     
         19 . The system controller of  claim 17 , wherein identifying the selected dispatch state based at least in part on the degradation value comprises performing an optimization routine based at least in part on the performance model, and wherein the optimization routine comprises:
 during each of a plurality of time periods, identifying a candidate dispatch state by incrementally adjusting a number of energy storage units to be coupled to the system; and   for each candidate dispatch state, determining a degradation value for the candidate dispatch state associated with the incremental adjustment.   
     
     
         20 . The system controller of  claim 19 , wherein the optimization routine further comprises:
 during each time period of the plurality of time periods, comparing the degradation value associated with the candidate dispatch state identified in the present time period with the degradation value associated with the candidate dispatch state identified in the previous time period; and   selecting the present candidate dispatch state as a selected dispatch state when the degradation value associated with the candidate dispatch state identified in the present time period is less than the degradation value associated with the candidate dispatch state identified in the previous time period.