Methods for electric bus charging to increase battery life

• US 9,496,735 B2
• Filed: 09/21/2011
• Issued: 11/15/2016
• Est. Priority Date: 09/21/2010
• Status: Active Grant

• Current Assignee: Proterra Powered LLC
• Original Assignee: Proterra AG
• Inventors: Sarkar, Reuben, McGrath, Seamus, Finnern, Michael Alan
• Primary Examiner(s): Fantu, Yalkew
• Assistant Examiner(s): Hernandez, Manuel
• Application Number:
  US13/825,531
• Publication Number:
  US 20130229153A1
• Time in Patent Office: 1,882 Days
• Field of Search: 320/109
• US Class Current: 1/1
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 2200/18 Buses
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2240/667 Precipitation
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 2260/58 Departure time prediction
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/18 Cables specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/63 : in response to network capacity
• CPC Class Codes: B60L 53/64 : Optimising energy costs, e.g. responding to electricity rates
• CPC Class Codes: B60L 53/65 : involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/665 : Methods related to measuring, billing or payment
• CPC Class Codes: B60L 55/00 : Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• CPC Class Codes: B60L 58/14 : Preventing excessive discharging
• CPC Class Codes: B60L 58/15 : Preventing overcharging
• CPC Class Codes: B60L 58/16 : responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/18 : of two or more battery modules
• CPC Class Codes: B60L 58/21 : having the same nominal voltage
• CPC Class Codes: B60L 58/25 : by controlling the electric load
• CPC Class Codes: B60L 58/26 : by cooling
• CPC Class Codes: H01M 10/441 : for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/46 : Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 16/00 : Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 2220/20 : Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0068 : Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: Y02E 60/00 : Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

The invention provides for an energy storage system that has a first plurality of battery cells that each are capable of a first C-rate. The plurality of battery cells can be charged at an equivalent rate on a kWh/minute basis as a second plurality of battery cells that each are capable of second C-rate, with the second C-rate being higher than the first C-rate. The first plurality of battery cells may have an energy storage capacity which is approximately twice the energy storage capacity for the second plurality of cells.

Claims

1. A method of charging an energy storage system of an electric bus at a charging station, the bus being configured to operate along a route and be charged at multiple charging events along the route, the method comprising:

electrically connecting the bus with the charging station for a first charging event of the multiple charging events;

receiving, at a control system, information relating to charging, the information including at least (a) a current state of charge of the bus and (b) information related to the route of the bus;

determining using the control system, based at least on the received information, an amount of energy needed by the bus until a second charging event, the second charging event being a charging event subsequent to the first charging event; and

charging the energy storage system with the determined amount of energy at the first charging event, wherein the charging includes;

(i) providing a first amount of energy to the energy storage system, the first amount of energy being smaller than the determined amount of energy;

(ii) discharging a second amount of energy from the energy storage system after providing the first amount of energy, the second amount of energy being smaller than the first amount of energy; and

(iii) providing a third amount of energy to the energy storage system after the discharging, the third amount of energy being a remaining amount of energy needed to charge the energy storage system with the determined amount of energy; and

electrically disconnecting the bus from the charging station after the first charging event.

2. The method of claim 1, wherein the determining further includes establishing what charging rate should be used to provide the determined amount of energy.

3. The method of claim 1, wherein the receiving information further includes receiving information related to (c) a current time of day of the first charging event, and (d) a forecasted weather along the route of the bus.

4. The method of claim 3, wherein the receiving information further includes receiving information related to (e) the demand rate of electricity supplied to the charging station at the current time.

5. The method of claim 1, wherein the receiving information further includes receiving information related to a route profile of the bus between the first charging event and the second charging event.

6. The method of claim 1, wherein the receiving information further includes receiving information related to a load on the utility grid supplying the charging station during the first charging event.

7. The method of claim 1, wherein the receiving information includes receiving information from the bus and receiving information from an external source remote from the bus and the charging station.

8. The method of claim 1, wherein determining the amount of energy includes determining the amount of energy based on at least a forecasted weather condition along the route of the bus.

9. The method of claim 8, wherein determining the amount of energy includes increasing the determined amount of energy when hot weather is forecasted compared to when cooler weather is forecasted.

10. The method of claim 1, wherein determining the amount of energy includes increasing the determined amount of energy during the night and early morning as compared to other times.

11. A method of charging an energy storage system of an electric bus at a charging station, the bus being configured to operate along a route and be charged at a first charging event and a second charging event subsequent to the first charging event along the route, the method comprising:

electrically connecting the bus with the charging station for the first charging event;

receiving, at a control system, information relating to charging, the information including at least (a) a current state of charge of the bus, (b) distance to the second charging event, and (c) demand rate of electricity at a current time;

determining using the control system, based at least on the received information, (i) an amount of energy needed by the bus to reach the second charging event and (ii) a rate of charging; and

charging the energy storage system with the determined amount of energy during the first charging event, wherein the charging includes;

(i) providing a first amount of energy to the energy storage system at the determined rate, the first amount of energy being smaller than the determined amount of energy;

(ii) discharging a second amount of energy from the energy storage system after providing the first amount of energy, the second amount of energy being smaller than the first amount of energy; and

(iii) providing a third amount of energy to the energy storage system after the discharging, the third amount of energy being a remaining amount of energy needed to charge the energy storage system with the determined amount of energy; and

electrically disconnecting the bus from the charging station after the first charging event.

12. The method of claim 11, wherein the receiving information further includes receiving information related to (d) a forecasted weather along the route of the bus, and (e) information related to the route of the bus.

13. The method of claim 12, wherein determining the amount of energy needed by the bus includes increasing the determined amount of energy when hot weather is forecasted compared to when cooler weather is forecasted.

14. The method of claim 11, wherein determining the amount of energy needed by the bus further includes determining the amount of energy based on historical passenger load data of the bus.

15. The method of claim 11, wherein determining the amount of energy needed by the bus further includes determining the amount of energy based on an historical HVAC usage data of the bus.

16. A method of charging an energy storage system of an electric bus at a charging station, the bus being configured to be charged at multiple charging events along a route, the method comprising:

electrically connecting the bus with the charging station for a first charging event of the multiple charging events;

receiving, at a control system, information relating to charging, the information including at least (a) a current state of charge of the bus (b) information related to the route of the bus, (c) forecasted weather along the route, and (d) a current cost of electricity;

determining using the control system, based at least on the received information, (i) an amount of energy needed by the bus until a second charging event subsequent to the first charging event, and (ii) a charging rate; and

charging the energy storage system with the determined amount of energy during the first charging event, wherein the charging includes;

(i) providing a first amount of energy to the energy storage system, the first amount of energy being smaller than the determined amount of energy;

(ii) discharging a second amount of energy from the energy storage system after providing the first amount of energy, the second amount of energy being smaller than the first amount of energy; and

(iii) providing a third amount of energy to the energy storage system after the discharging, the third amount of energy being a remaining amount of energy needed to charge the energy storage system with the determined amount of energy; and

electrically disconnecting the bus from the charging station after the first charging event.

17. The method of claim 16, wherein determining the amount of energy needed by the bus includes increasing the determined amount of energy when hot weather is forecasted compared to when cooler weather is forecasted.

18. The method of claim 16, wherein determining the amount of energy needed by the bus includes increasing the determined amount of energy during the night and early morning as compared to other times.

19. The method of claim 16, wherein determining the amount of energy needed by the bus further includes determining the amount of energy based on an historical HVAC usage data of the bus.

20. The method of claim 16, wherein determining the amount of energy needed by the bus further includes determining the amount of energy based on historical passenger load data of the bus.