CONTROLLING BATTERIES FOR ELECTRIC BUS

• US 20150280466A1
• Filed: 10/01/2014
• Published: 10/01/2015
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: New Flyer Industries Canada ULC (NFI Group, Inc.)
• Original Assignee: New Flyer Industries Canada ULC (NFI Group, Inc.)
• Inventors: Naylor, David Glen, OWEN, Robert Brydon Thomas
• Granted Patent: US 9,748,777 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 1/06 using only one supply
• CPC Class Codes: B60L 1/14 to electric lighting circuits
• CPC Class Codes: B60L 2200/18 Buses
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/62 Vehicle position
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/12 by confirmation, e.g. of the input
• CPC Class Codes: B60L 2250/16 by display
• 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 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/30 : Constructional details of charging stations
• CPC Class Codes: B60L 53/32 : by charging in short intervals along the itinerary, e.g. during short stops
• CPC Class Codes: B60L 53/65 : involving identification of vehicles or their battery types
• CPC Class Codes: B60L 58/12 : responding to state of charge [SoC]
• CPC Class Codes: B60L 58/21 : having the same nominal voltage
• CPC Class Codes: H02J 2310/48 : for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/00041 : in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/00047 : with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0013 : acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0014 : Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0048 : Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0049 : Detection of fully charged condition
• 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 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

An onboard charging system for an electric vehicle is configured to communicate with a power supply through exchange of control signals on a power supply line by modulating a charging current being supplied to the charging system. The charging system is capable of communicating fault and battery parameter data to the power supply, as well as a requested charging current used to regulate the power supply output. The power supply may convert high voltage AC power into a controllable DC output supplied directly to the electric vehicle, thereby providing a convenient means for the vehicle to initiate charging during operations. Connection between the electric vehicle and the power supply may be effected using an extendible and retractable electrical connection, such as a mechanical pantograph.

Claims

1. A charge control system for one or more energy storage devices, comprising:

a power supply line connectable to a power supply to transmit a charge current for the one or more energy storage devices;

a charge controller configured to monitor one or more parameters indicative of respective states of charge in the one or more energy storage devices and to control the charge current for the one or more energy storage devices based on the one or more monitored parameters; and

a communication subsystem coupled to the power supply line and the charge controller, the communication subsystem configured to receive control signals generated by the charge controller for transmission to the power supply and to modulate the charge current on the power supply line according to the control signals received from the charge controller.

2. The system of claim 1, wherein the communication subsystem is further configured to detect charge current modulations on the power supply line representing control signals generated by the power supply and to generate control signals for execution by the charge controller based on the detected charge current modulations.

3. The system of claim 1, wherein the charge current comprises:

a direct current (DC) component corresponding to a charging current for the one or more energy storage devices, the DC component supplied by the power supply in response to the control signals generated by the charge controller; and

an alternating current (AC) component corresponding to modulations of the charge current representing control signals transmitted over the power supply line.

4. The system of claim 1, wherein the charge control system is installed on a mobile transport vehicle, and the power supply comprises a high voltage source situated externally to the mobile transport.

5. A method of charging a plurality of energy storage devices, comprising:

supplying a charging current to a first grouping of the energy storage devices comprising one or more energy storage devices currently connected to a power supply line;

selecting an energy storage device for connection to the power supply line from a second grouping of the energy storage devices comprising one or more energy storage devices not currently connected to the power supply line; and

connecting the selected energy storage device to the power supply line when it is determined that a group voltage of the one or more energy storage devices in the first grouping and the voltage of the energy storage device selected from the second grouping are within a specified maximum difference of each other.

6. The method of claim 5, wherein the one or more energy storage devices in the first grouping are connected in parallel to the power supply line.

7. The method of claim 6, wherein the selected energy storage device from the second grouping is connected to the power supply line in parallel with the one or more energy storage devices in the first grouping.

8. The method of claim 5, wherein the selected energy storage device has a lowest voltage among the one or more energy storage devices in the second grouping.

9. The method of claim 8, further comprising:

measuring a voltage of each energy storage device in the second grouping; and

determining the lowest voltage energy device in the second grouping based on comparison of the measured voltages.

10. The method of claim 9, further comprising:

monitoring the group voltage of the one or more energy storage devices in the first grouping connected to the power supply line; and

determining when to connect the selected energy storage device from the second grouping to the power supply line based on comparison of the monitored group voltage and the measured voltage of the selected energy storage device.

11. A method of charging a plurality of energy storage devices, comprising:

connecting an initial grouping of the energy storage devices to a power supply line, the initial grouping comprising one or more energy storage devices determined to have respective voltages within a specified maximum difference of each other;

supplying the initial grouping of energy storage devices with a charging current on the power supply line;

connecting a remainder of the energy storage devices not included in the initial grouping to the power supply line by, for each respective energy storage device in the remainder, connecting the respective energy storage device to the power supply line when it is determined that a group voltage of the one or more energy storage devices currently connected to the power supply line and the voltage of the respective energy storage device in the remainder are within a specified maximum difference of each other; and

discontinuing supply of the charging current on the power supply line when it is determined that the plurality of energy storage devices are charged to a specified full charge voltage.

12. The method of claim 11, wherein the one or more energy storage devices in the initial grouping are connected in parallel to the power supply line.

13. The method of claim 12, wherein each respective energy storage device in the remainder is connected to the power supply line in parallel with the one or more energy storage devices currently connected to the power supply line.

14. The method of claim 11, further comprising:

measuring an initial voltage of each of the plurality of energy storage devices; and

determining the initial grouping of the energy storage devices based on comparison of the measured initial voltages.

15. The method of claim 14, further comprising:

monitoring the group voltage of the one or more energy storage devices currently connected to the power supply line; and

determining when to connect the remainder of the plurality of energy storage devices to the power supply line, for each respective energy storage device in the remainder, based on comparison of the monitored group voltage and the measured initial voltage of the respective energy storage device in the remainder.

16. A method of drawing power from a plurality of energy storage devices, comprising:

supplying one or more loads with a current drawn from a first grouping of a plurality of energy storage devices connected to a power supply line;

selecting one or more energy storage devices for connection to the power supply line from a second grouping of the energy storage devices comprising one or more energy storage devices not currently connected to the power supply line; and

connecting the selected energy storage device(s) to the power supply line when it is determined that a group voltage of the one or more energy storage devices in the first grouping and the voltage of the energy storage device selected from the second grouping are within a specified maximum difference of each other.

17. The method of claim 16, wherein the one or more energy storage devices in the first grouping are connected in parallel to the power supply line.

18. The method of claim 17, wherein the selected energy storage device from the second grouping is connected to the power supply line in parallel with the one or more energy storage devices in the first grouping.

19. The method of claim 16, wherein the selected energy storage device has a highest voltage among the one or more energy storage devices in the second grouping.

20. The method of claim 19, further comprising:

measuring a voltage of each energy storage device in the second grouping; and

determining the highest voltage energy device in the second grouping based on comparison of the measured voltages.

21. The method of claim 20, further comprising:

monitoring the group voltage of the one or more energy storage devices in the first grouping connected to the power supply line; and

determining when to connect the selected energy storage device from the second grouping to the power supply line based on comparison of the monitored group voltage and the measured voltage of the selected energy storage device.

22. A method of drawing power from a plurality of energy storage devices, the method including:

connecting an initial grouping of the energy storage devices to a power supply line, the initial grouping comprising one or more energy storage devices determined to have respective voltages within a specified maximum difference of each other;

supplying one or more loads with a load current drawn from the initial grouping of energy storage devices on the power supply line;

connecting a remainder of the energy storage devices not included in the initial grouping to the power supply line by, for each respective energy storage device in the remainder, connecting the respective energy storage device to the power supply line when it is determined that a group voltage of the one or more energy storage devices currently connected to the power supply line and the voltage of the respective energy storage device in the remainder are within a specified maximum difference of each other; and

discontinuing supply of the load current on the power supply line when it is determined that the plurality of energy storage devices is depleted to a specified charge state.

23. The method of claim 22, wherein the one or more energy storage devices in the initial grouping are connected in parallel to the power supply line.

24. The method of claim 23, wherein each respective energy storage device in the remainder is connected to the power supply line in parallel with the one or more energy storage devices currently connected to the power supply line.

25. The method of claim 22, further comprising:

measuring an initial voltage of each of the plurality of energy storage devices; and

determining the initial grouping of the energy storage devices based on comparison of the measured initial voltages.

26. The method of claim 25, further comprising:

monitoring the group voltage of the one or more energy storage devices currently connected to the power supply line; and

determining when to connect the remainder of the plurality of energy storage devices to the power supply line, for each respective energy storage device in the remainder, based on comparison of the monitored group voltage and the measured initial voltage of the respective energy storage device in the remainder.