Electric vehicle charging to reduce utility cost

Abstract

A method for controlling the charging of one or more electric vehicles at one or more charging stations in a geographic locality includes determining if the charging event of an electric vehicle of the one or more electric vehicles increases a demand billing rate. The demand billing rate may be a cost per unit of energy in the locality. The method also includes charging the electric vehicle at the charging event such that the demand billing rate is not increased.

1 - 20 . (canceled) 
     
     
         21 . A method used by a control system to charge a vehicle at a charging station in a geographic location, comprising:
 using, by the control system, a rolling time window of one or more charging events of the vehicle at the charging station to avoid increasing utility cost calculations of the one or more charging events by:
 sliding, when a first time window of the rolling time window ends, the rolling time window a predetermined amount along a time axis to start a second time window of the rolling time window; 
 dropping portions of an energy consumption curve of the rolling time window as the rolling time window drops out of the second time window thereby freeing up energy capable of being consumed by the vehicle at the charging station in the second time window; and 
 upon determining that the freed up energy in the second time window is sufficient to provide an additional energy (E ADDITIONAL ) to the vehicle at a default charging rate without increasing the utility cost calculations of the one or more charging events, charging the vehicle at the default charging rate. 
   
     
     
         22 . The method of  claim 21 , wherein the control system using the rolling time window further comprises:
 upon determining that the freed up energy in the second time window is insufficient to provide the additional energy (E ADDITIONAL ) to the vehicle at the default charging rate, charging the vehicle at a lower charging rate than the default charging rate so that that a maximum amount of energy (E MAX ) that can be consumed by the charging station within the second time window is not exceeded.   
     
     
         23 . The method of  claim 21 , wherein the control system using the rolling time window further comprises:
 resetting a total energy count by starting a third time window after the second window;   sliding, when the second time window of the rolling time window ends, the rolling time window another predetermined amount on the time axis to start the third time window of the rolling time window;   dropping portions of the energy consumption curve of the rolling time window as the rolling time window drops out of the third time window thereby freeing up energy capable of being consumed in the third time window   upon determining that the freed up energy in the third time window is sufficient to provide another additional energy to the vehicle at the default charging rate, charging the vehicle at the default charging rate.   
     
     
         24 . The method of  claim 21 , wherein the utility cost calculations comprise a cost per unit of energy and accounts for a demand charge for energy consumed by the charging station. 
     
     
         25 . A method of using a control system to control charging of one or more electric vehicles at one or more charging stations in a geographic locality, the method comprising:
 determining, by the control system, a maximum amount of energy (E MAX ) that can be consumed by the one or more charging stations within a reference time window without increasing a demand billing rate, E MAX  being determined based on a schedule optimization routine that considers a charging schedule of the one or more electric vehicles operating in the geographic locality and one or more vehicle-specific factors;   determining, by the control system, a total amount of energy already consumed (E USED ) by the one or more charging stations in the reference time window by tracking E USED  between a first time and a second time in the reference time window and summing the tracked E USED  between the first time and the second time in the reference time window;   determining, by the control system, an amount of energy needed (E NEED ) by the one or more electric vehicles based on summing the tracked E USED  and E MAX .   
     
     
         26 . The method of  claim 25 , wherein the step of determining, by the control system, E USED  comprises determining the total energy consumed by each of the one or more charging stations in the reference time window up to a current time. 
     
     
         27 . The method of  claim 25 , wherein the step of determining, by the control system, E NEED  is further based on a residual state-of-charge (SOC) of a battery capacity of the one or more electric vehicles before charging begins. 
     
     
         28 . The method of  claim 27 , further comprising:
 notifying, by the one or more vehicle, to the control system a current SOC prior to, or after, docking with the one or more charging stations.   
     
     
         29 . The method of  claim 25 , wherein the step of determining, by the control system, E MAX  is calculated based on historic energy consumption data of the one or more electric vehicles. 
     
     
         30 . The method of  claim 25 , further comprising:
 upon determining, by the control system, that E USED  and a minimum amount of energy (E MIN ) needed by the one or more electric vehicles until a next charging event is greater than E MAX , providing at a reduced charging rate an amount of energy to the one or more electric vehicles that is equal to E MIN .   
     
     
         31 . The method of  claim 30 , further comprising:
 determining, by the control system, the reduced charging rate based on whether a demand limit for the reference time window is exceeded.   
     
     
         32 . The method of  claim 30 , further comprising:
 selecting, by the control system, the reduced charging rate so that only an available amount of energy equal (E AVAILABLE ) is provided to the one or more electric vehicles in a remaining amount of time in the reference time window.   
     
     
         33 . The method of  claim 32 , further comprising:
 providing a remaining amount of energy to the one or more electric vehicles after expiry of the reference time window.   
     
     
         34 . The method of  claim 25 , further comprising:
 upon determining that a minimum amount of energy (E MIN ) needed by the one or more electric vehicles until a next charging event will cause a total energy consumed in the reference time window to exceed E MAX , de-rating a charge current so that only an available amount of energy equal (E AVAILABLE ) in the reference time window is provided to the one or more electric vehicles.   
     
     
         35 . The method of  claim 25 , further comprising:
 upon determining that an amount of energy equal to an available amount of energy equal (E AVAILABLE ) in the reference time window is insufficient for the one or more electric vehicles to complete a route, providing an additional energy (E ADDITIONAL ) to the one or more electric vehicles after the reference time window ends and a new reference time window begins.   
     
     
         36 . The method of  claim 25 , wherein the step of determining, by the control system, the maximum amount of energy (E MAX ) comprises determining the maximum amount of energy (E MAX ) capable of being consumed in the reference time window without triggering a rate hike. 
     
     
         37 . The method of  claim 25 , further comprising:
 generating, by the control system, an energy consumption curve comprising a plurality of time periods of the reference time window, wherein each time period comprises points reflecting the one or more vehicles being charged prior to a current time and plateaus reflecting time periods when the one or more charging stations is idle corresponding to when the one or more vehicles are not being charged.   
     
     
         38 . The method of  claim 21 , further comprising:
 upon determining, by the control system, that the E USED  and a minimum amount of energy (E MIN ) needed by the one or more electric vehicles until a next charging event is greater than E MAX , deactivating, by the control system, energy for one or more non-essential power consumption sources of the one or more vehicles during travel to a next charging event.   
     
     
         39 . The method of  claim 38 , wherein the non-essential power consumption sources are deactivated by the control system based on a time of day and/or a prevailing weather condition. 
     
     
         40 . A charging station for an electric vehicle, comprising:
 charging electrodes configured to electrically couple with charge-receiving electrodes of an electric vehicle during a charging event; and   a control system configured to:   use a rolling time window of one or more charging events of the vehicle at the charging station to avoid increasing utility cost calculations of the one or more charging events by:   sliding, when a first time window of the rolling time window ends, the rolling time window a predetermined amount along a time axis to start a second time window of the rolling time window;   dropping portions of an energy consumption curve of the rolling time window as the rolling time window drops out of the second time window thereby freeing up energy capable of being consumed by the vehicle at the charging station in the second time window; and   upon determining that the freed up energy in the second time window is sufficient to provide an additional energy (E ADDITIONAL ) to the vehicle at a default charging rate without increasing the utility cost calculations of the one or more charging events, charging the vehicle at the default charging rate.