SYSTEM FOR CAUSING TEMPERATURE RISE IN BATTERY

• US 20120153877A1
• Filed: 12/20/2011
• Published: 06/21/2012
• Est. Priority Date: 12/20/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation, Nippon Soken, Inc.
• Original Assignee: DENSO Corporation, Nippon Soken, Inc.
• Inventors: BABA, Hiroyasu, IRITANI, Kunio, TOKUNAGA, Masao
• Granted Patent: US 8,766,566 B2
• Time in Patent Office: Days
• US Class Current: 318/139
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery temperature rise causing system has a converting unit for converting voltage of electric power held in one of a rechargeable battery and a capacitor and applies the converted voltage to the other one, and a control unit controlling the converting unit to alternately perform first transfer of electric power from the battery to the capacitor and second transfer of electric power from the capacitor to the battery while changing the first transfer for the second transfer each time the battery voltage reaches a lower limit and changing the second transfer for the first transfer each time the battery voltage reaches an upper limit, and to increase temperature of the battery due to heat generated by electric current flowing through the battery during the electric power transfer.

Claims

1. A battery temperature rise causing system, comprising:

a rechargeable battery that holds electric power;

an accumulator that accumulates the electric power received from the battery;

a voltage converting unit that performs voltage conversion of the electric power between the battery and the accumulator; and

a control unit that receives a battery temperature of the battery and controls the converting unit, when the received battery temperature is lower than a reference value, to increase the battery temperature while alternately transferring electric power from the accumulator to the battery and from the battery to the accumulator,

wherein the control unit receives a battery voltage of the battery and controls the converting unit to change a transfer direction of the electric power between the battery and the capacitor each time the received battery voltage reaches a battery upper limit or a battery lower limit.

2. The system according to claim 1, wherein the control unit controls the converting unit to transfer the electric power from the battery to the accumulator in response to the battery voltage reaching the battery upper limit and to transfer the electric power from the accumulator to the battery in response to the battery voltage reaching the battery lower limit.

3. The system according to claim 1, wherein the control unit receives an accumulated power voltage of the accumulator and controls the converting unit to change the transfer direction of the electric power between the battery and the capacitor each time the accumulated power voltage reaches an accumulator upper limit or an accumulator lower limit.

4. The system according to claim 3, wherein the control unit controls the converting unit to perform the transfer of the electric power from the accumulator to the battery in response to the accumulated power voltage reaching the accumulator upper limit and to perform the transfer of the electric power from the battery to the accumulator in response to the accumulated power voltage reaching the accumulator lower limit.

5. The system according to claim 3, wherein the control unit controls the converting unit to transfer the electric power from the accumulator to the battery when a predetermined period of time has elapsed from a start of the transfer of the electric power from the battery to the accumulator before the accumulated power voltage reaches the accumulator upper limit.

6. The system according to claim 3, wherein the control unit controls the converting unit to transfer the electric power from the battery to the accumulator when a predetermined period of time has elapsed from a start of the transfer of the electric power from the accumulator to the battery before the accumulated power voltage reaches the accumulator lower limit.

7. The system according to claim 1, wherein the control unit receives a conversion current flowing through the converting unit and controls the converting unit to change the transfer direction of the electric power between the battery and the capacitor each time the conversion current reaches a conversion upper limit.

8. The system according to claim 1, wherein the control unit controls the converting unit, when the voltage of the battery is lower than a predetermined value, to stop transferring the electric power between the battery and the accumulator.

9. A battery temperature rise causing system, comprising:

a rechargeable battery that holds electric power;

an accumulator that accumulates the electric power received from the battery;

a voltage converting unit that performs voltage conversion of the electric power between the battery and the accumulator; and

a control unit that receives a battery temperature of the battery and controls the converting unit, when the received battery temperature is lower than a reference value, to increase the battery temperature while alternately transferring electric power from the accumulator to the battery and from the battery to the accumulator,

wherein the control unit stores in advance data indicating a relation between frequency in the transfer of the electric power and calorific power, generated in the battery due to the alternated transfer of the electric power, for each of levels of the battery temperature on condition that a battery voltage of the battery is lower than a battery upper limit and is higher than a battery lower limit, determines an optimum frequency at which the calorific power corresponding to the received battery temperature is maximized, and controls the converting unit to change a transfer direction of the electric power between the battery and the capacitor at the optimum frequency.

10. The system according to claim 9, wherein the control unit stores in advance the data indicating the relation between the frequency and the calorific power for each of levels of remaining capacity in the battery, selects the relation corresponding to a present level of remaining capacity, determines the optimum frequency, at which the calorific power corresponding to the received battery temperature is maximized, by using the selected relation, and controls the converting unit to change the transfer direction of the electric power at the optimum frequency.

11. The system according to claim 9, wherein the control unit changes a value of the optimum frequency in response to a change in a value of the received battery temperature, and controls the converting unit to change the transfer direction of the electric power at the optimum frequency set at the changed value.

12. A battery temperature rise causing system, comprising:

a rechargeable battery that holds electric power;

an accumulator that accumulates the electric power received from the battery;

a voltage converting unit that performs voltage conversion of the electric power between the battery and the accumulator; and

a control unit that receives a battery temperature of the battery and controls the converting unit, when the received battery temperature is lower than a reference value, to increase the battery temperature while alternately transferring electric power from the accumulator to the battery and from the battery to the accumulator,

wherein the control unit stores in advance data indicating a relation between frequency in the transfer of the electric power and battery current flowing through the battery, for each of levels of battery temperature on condition that a battery voltage of the battery is lower than a battery upper limit and is higher than a battery lower limit, determines an optimum frequency at which calorific power generated in the battery due to the alternated transfer of the electric power is maximized, by using the relation corresponding to the level of the received battery temperature, and controls the converting unit to change a transfer direction of the electric power between the battery and the capacitor at the optimum frequency.

13. The system according to claim 12, wherein the control unit stores in advance the data indicating the relation between the frequency and the battery current for each of levels of remaining capacity in the battery, selects the relation corresponding to an electric current level of remaining capacity, determines the optimum frequency, at which the calorific power corresponding to the received battery temperature is maximized, by using the selected relation, and controls the converting unit to change the transfer direction of the electric power at the optimum frequency.

14. The system according to claim 12, wherein the control unit changes a value of the optimum frequency in response to a change in a value of the received battery temperature, and controls the converting unit to change the transfer direction of the electric power between the battery and the capacitor at the optimum frequency set at the changed value.

15. A battery temperature rise causing system, comprising:

a rechargeable battery that holds electric power;

an accumulator that accumulates the electric power received from the battery or accumulates electric power regenerated in an electric motor;

a voltage converting unit that performs voltage conversion of the electric power between the battery and the accumulator;

an inverter that converts an accumulated power voltage of the electric power accumulated in the accumulator into an alternating current voltage and applying the alternating current voltage to the electric motor to drive the electric motor during running of a vehicle; and

a control unit that receives a battery temperature of the battery and controls the converting unit, when the received battery temperature is lower than a reference value, to increase the battery temperature while alternately transferring electric power from the accumulator to the battery and transferring electric power from the battery to the accumulator,

wherein the control unit determines a driving voltage, required to drive the electric motor, according to a running condition of the vehicle, receives the accumulated power voltage of the accumulator and a battery voltage of the battery, and controls the converting unit according to the driving voltage, the accumulated power voltage and the battery voltage to alternately perform the transfers of the electric power.

16. The system according to claim 15, wherein, when the determined driving voltage is lower than a predetermined threshold value being equal to a maximum of a voltage required to drive the electric motor while the accumulated power voltage is higher than the determined driving voltage, the control unit controls the converting unit to alternately perform the transfers of the electric power.

17. The system according to claim 15, wherein the control unit controls the converting unit to transfer the electric power from the battery to the accumulator in response to the battery voltage reaching an upper limit and to transfer the electric power from the accumulator to the battery in response to the battery voltage reaching a lower limit.

18. The system according to claim 15, wherein the control unit controls the converting unit to transfer the electric power from the accumulator to the battery in response to the accumulated power voltage reaching an upper limit and, to transfer the electric power from the battery to the accumulator in response to the accumulated power voltage reaching a lower limit.

19. The system according to claim 18, wherein the control unit controls the converting unit to transfer the electric power from the accumulator to the battery when a predetermined period of time has elapsed from a start of the transfer of the electric power from the battery to the accumulator before the accumulated power voltage reaches the upper limit.

20. The system according to claim 18, wherein the control unit controls the converting unit to transfer the electric power from the battery to the accumulator when a predetermined period of time has elapsed from a start of the transfer of the electric power from the accumulator to the battery before the accumulated power voltage reaches the lower limit.