Depot charging of an electric vehicle fleet

Abstract

Vehicle depots or yards adapted to charge multiple electric vehicles include multiple charging electrodes to simultaneously direct power to multiple electric vehicles. The charging electrodes may direct power to the electric vehicles from an utility grid or from a secondary power source.

1 - 20 . (canceled) 
     
     
         21 . A depot configured to charge a fleet of electric buses, comprising:
 a plurality of charging electrodes configured to charge battery systems of the electric buses;   a rectifier configured to receive AC current from a power grid and convert to DC current directed to a common busbar, the common busbar configured to distribute the DC current to each of the charging electrodes, the charging electrodes being electrically connected to the common busbar in parallel; and   a control system configured to manage power between the power grid and the common busbar, wherein the control system is configured to selectively discharge power from battery systems of the electric buses to the power grid and/or a battery pack of the depot.   
     
     
         22 . The depot of  claim 21 , wherein each of the plurality of electric buses comprises an AC contactor, an isolation transformer, and a converter that receives and converts AC current from the depot for delivery to the respective battery system of the respective electric bus,
 wherein the isolation transformer isolates the respective electric bus from other of the plurality of electric buses connected to the common busbar.   
     
     
         23 . The depot of  claim 22 , wherein the isolation transformer is configured to step down voltage of the AC current received for delivery to the battery system of the respective electric bus. 
     
     
         24 . The depot of  claim 22 , wherein the converter is a bi-directional inverter configured for AC to DC conversion and DC to AC conversion, and
 wherein the converter is configured to convert DC power from the respective battery system of the respective bus to AC power and direct AC power to the power grid via the common busbar.   
     
     
         25 . The depot of  claim 21 , wherein the control system is distributed between the electric buses and the depot, and wherein the control system comprises multiple controllers or control units in one or more of the electric buses and in the depot. 
     
     
         26 . The depot of  claim 21 , wherein the control system comprises one or more controllers and one or more DC-DC converters on the electric buses to control power on the common busbar. 
     
     
         27 . The depot of  claim 21 , wherein each electric bus comprises an isolated DC-DC charger controlled by the control system to control charging of the respective electric bus. 
     
     
         28 . The depot of  claim 21 , wherein the control system is configured to control the discharge of power from at least one of the electric buses and direct the discharged power to other of the plurality of electric buses. 
     
     
         29 . The depot of  claim 21 , wherein the control system is configured to track a total energy consumed at the depot by the electric buses during a time frame, and
 wherein based on the total energy consumed, the control system is configured to direct power from one or more solar panels and/or battery systems of the depot when a total energy consumption exceeds a threshold value that will result in increased demand charges.   
     
     
         30 . The depot of  claim 21 , wherein the control system is configured to determine, based on historic energy consumption data of the depot, a maximum permissible energy consumption (Emax) for a current reference time period without triggering a demand rate increase. 
     
     
         31 . A depot configured to charge a fleet of electric buses, comprising:
 a plurality of parking locations, each of the plurality of parking locations configured to receive a respective electric bus of the fleet of electric buses;   a plurality of charge cables, each of the plurality of charge cables having a plug end positioned proximate to a corresponding one of the plurality of parking locations and configured couple to a charge port of the respective electric bus to charge the respective electric bus;   a common busbar to receive converted DC current from a power grid and distribute the converted DC current to each of the charging cables, the plurality of electric buses being electrically connected via the respective cable to the common busbar in parallel; and   a control system configured to manage power between the power grid and the common busbar, wherein the control system is configured to selectively discharge power from battery systems of the electric buses to the power grid and/or a battery pack of the depot.   
     
     
         32 . The depot of  claim 31 , further comprising:
 a plurality of transformers, each of the plurality of transformers positioned between the common busbar and a rectifier.   
     
     
         33 . The depot of  claim 32 , wherein the depot is configured to simultaneously charge a plurality of electric buses from the fleet of electric buses, each of the plurality of electric buses parked in a respective parking location and electrically connected to the corresponding one of the charging cables. 
     
     
         34 . The depot of  claim 33 , wherein each of the plurality of electric buses comprises an AC contactor, an isolation transformer, and a converter that receives and converts AC current from the depot for delivery to the respective battery system of the respective electric bus. 
     
     
         35 . The depot of  claim 34 , wherein the isolation transformer isolates the respective electric bus from other of the plurality of electric buses connected to the common busbar. 
     
     
         36 . The depot of  claim 35 , wherein the converter is a bi-directional inverter configured for AC to DC conversion and DC to AC conversion. 
     
     
         37 . The depot of  claim 36 , wherein the converter is configured to convert DC power from battery system of the respective bus to AC power and direct AC power to the power grid via the common busbar. 
     
     
         38 . A method of charging a fleet of electric buses, comprising:
 converting, by a rectifier, AC current from a power grid to DC current;   directing the converted DC current to a common busbar,   electrically connecting the electric buses to the common busbar in parallel;   distributing, by the common busbar, the converted DC current to charging electrodes of each of the electric buses; and   managing, by a control system, power between the power grid and the common busbar by selectively discharging power from battery systems of the electric buses to the power grid and/or a battery pack of a corresponding charging depot.   
     
     
         39 . The method of  claim 38 , wherein each of the electric buses comprises an AC contactor, a transformer, and a converter, the method further comprising:
 receiving and converting, by the converter, AC current from the depot for delivery to the respective battery system of the respective electric bus; and   isolating, by the transformer, a respective electric bus from other of the electric buses connected to the common busbar.   
     
     
         40 . The method of  claim 39 , wherein the converter is a bi-directional inverter configured for AC to DC conversion and DC to AC conversion, the method further comprising:
 converting, by the converter, DC power from the respective battery system of a respective electric bus to AC power and directing AC power to the power grid via the common busbar.