Power control device and power control method for measuring open-circuit voltage of battery

Patent metadata

Field	Value
Publication number	US-9331512-B2
Application number	US-201314395072-A
Country	US
Kind code	B2
Filing date	Mar 26, 2013
Priority date	May 11, 2012
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A power control device includes a relay switch, a controller, a sensor and a battery controller. The relay switch is configured to turn electricity on and off between a battery for supplying a load with electric power and the load. The controller predicts load power characteristics indicating characteristics of power consumed by the load over time, and predicts, based on the predicted load power characteristics, charge/discharge power characteristics indicating characteristics of charge/discharge power of the battery over time. The sensor detects voltage between the terminals of the battery. The controller specify a voltage detection period from the charge/discharge power characteristics that was predicted, over which the charge/discharge power of the battery is equal to or less than a prescribed power over a prescribed period. The battery controller turns off the relay switch and detects the voltage between the battery terminals during the voltage detection period.

First claim

The invention claimed is:

1. A power control device comprising:
a relay switch configured to be connected between a battery for supplying a load with electric power and the load, the relay switch being configured to switch between turning electricity on and off from the battery;
a controller programmed to predict a load power characteristic indicating power consumed by the load over time, and to predict, based on the predicted load power characteristic, a charge/discharge power characteristic indicating power charged/discharged by the battery over time;
a sensor configured to detect voltage between terminals of the battery; and
a battery controller operatively coupled to the relay switch, and programmed to selectively control the relay switch,
the controller being programmed to specify a voltage detection period from the charge/discharge power characteristic that was predicted, over which the power charged/discharged by the battery is equal to or less than a prescribed power over a prescribed period, and
the battery controller being programmed to turn off the relay switch and to detect an open-circuit voltage based on the voltage between terminals of the battery during the voltage detection period.

2. The power control device according to claim 1 , further comprising
power-generating means for generating electric power and charging the battery using the generated electric power;
the controller being further programmed to predict a generated-power characteristic indicating the electric power generated by the power-generating means over time, and
the controller being further programmed to predict the charge/discharge power characteristic from the generated-power characteristic and the load power characteristic.

3. The power control device according to claim 2 , further comprising
an external power source capable of charging the battery;
the controller being further programmed to cause the battery to charge using the external power source during a period obtained by subtracting the voltage detection period from a period set in advance in which it is possible to charge the battery using electric power from the external power source.

4. The power control device according to claim 3 , wherein
the external power source is a commercial power source; and
the controller being further programmed to cause the battery to charge using electric power from a commercial power source during a midnight-power time slot.

5. The power control device according to claim 2 , wherein
the controller is further programmed to predict a necessary state of charge for the battery from the load power characteristics; and
the controller is further programmed to set a target value for charging the battery, in accordance with the necessary state of charge that was predicted.

6. The power control device according to claim 2 , wherein
the controller is further programmed to set a charging time period, which is obtained by subtracting the voltage detection period from a period set in advance in which it is possible to charge the battery using electric power from the external power source; and
the controller being further programmed to cause the battery to charge to a fully-charged state during the charging time period.

7. The power control device according to claim 2 , wherein
the prescribed period is set to be equal to or greater than a period from when the relay switch is turned off until when the voltage between the terminals of the battery stabilizes.

8. The power control device according to claim 1 , further comprising
an external power source capable of charging the battery;
the controller being further programmed to cause the battery to charge using the external power source during a period obtained by subtracting the voltage detection period from a period set in advance in which it is possible to charge the battery using electric power from the external power source.

9. The power control device according to claim 8 , wherein
the external power source is a commercial power source; and
the controller being further programmed to cause the battery to charge using electric power from a commercial power source during a midnight-power time slot.

10. The power control device according to claim 9 , wherein
the controller is further programmed to predict a necessary state of charge for the battery from the load power characteristics; and
the controller is further programmed to set a target value for charging the battery, in accordance with the necessary state of charge that was predicted.

11. The power control device according to claim 9 , wherein
the controller is further programmed to set a charging time period, which is obtained by subtracting the voltage detection period from a period set in advance in which it is possible to charge the battery using electric power from the external power source; and
the controller being further programmed to cause the battery to charge to a fully-charged state during the charging time period.

12. The power control device according to claim 9 , wherein
the prescribed period is set to be equal to or greater than a period from when the relay switch is turned off until when the voltage between the terminals of the battery stabilizes.

13. The power control device according to claim 8 , wherein
the controller is further programmed to predict a necessary state of charge for the battery from the load power characteristics; and
the controller is further programmed to set a target value for charging the battery, in accordance with the necessary state of charge that was predicted.

14. The power control device according to claim 8 , wherein
the controller is further programmed to set a charging time period, which is obtained by subtracting the voltage detection period from a period set in advance in which it is possible to charge the battery using electric power from the external power source; and
the controller being further programmed to cause the battery to charge to a fully-charged state during the charging time period.

15. The power control device according to claim 8 , wherein
the prescribed period is set to be equal to or greater than a period from when the relay switch is turned off until when the voltage between the terminals of the battery stabilizes.

16. The power control device according to claim 1 , wherein
the controller is further programmed to predict a necessary state of charge for the battery from the load power characteristics; and
the controller is further programmed to set a target value for charging the battery, in accordance with the necessary state of charge that was predicted.

17. The power control device according to claim 1 , wherein
the controller is further programmed to set a charging time period, which is obtained by subtracting the voltage detection period from a period set in advance in which it is possible to charge the battery using electric power from the external power source; and
the controller being further programmed to cause the battery to charge to a fully-charged state during the charging time period.

18. The power control device according to claim 1 , wherein
the prescribed period is set to be equal to or greater than a period from when the relay switch is turned off until when the voltage between the terminals of the battery stabilizes.

19. A power control method for controlling electric power comprising:
predicting a load characteristic indicating electric power consumed by a load over time, the load being driven by electric power supplied fr

Assignees

• Nissan Motor

Inventors

• Tsukamoto Yukari

Classifications

• B60L58/15

  Preventing overcharging · CPC title

• B60L2210/40

  DC to AC converters · CPC title

• B60L8/003

  Converting light into electric energy, e.g. by using photo-voltaic systems · CPC title

• B60L50/16

  with provision for separate direct mechanical propulsion · CPC title

• Y04S30/14

  Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing · CPC title