JP2014193014A - Charge controller, charger and charge control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge controller capable of preventing reduction of service life of a lead battery by performing refresh charge when needed.SOLUTION: A charge controller 100 controls charging of a lead battery 150. An SOC detection section 101 detects SOC of the lead battery 150. A sulfation generation amount detection section 103 calculates a relationship between the time and the reduction amount of the SOC from the detection result of the SOC input by the SOC detection section 101 and the time measured by a timer 102 to estimate the generation of sulfation. A charge control section 105 reads the estimation result of the generation of sulfation from a storage 104 and controls a charge unit 106 to switch between an ordinary charge and refresh charge on the basis of the read estimation result.

Description

  The present invention relates to a charging control device, a charging device, and a charging control method for controlling charging of a lead battery.

  Generally, in a lead battery, poorly soluble sulfation (lead sulfate; PbSO4) is generated due to a decrease in SOC (State Of Charge) and standing. When sulfation occurs, the battery capacity when the lead battery is fully charged decreases.

  For this reason, conventionally, for example, by periodically charging the lead battery once every seven days, sulfation is eliminated, and a decrease in battery capacity when the lead battery is fully charged is avoided ( For example, Patent Document 1).

Japanese Patent No. 4687768

  However, conventionally, since refresh charging is performed regularly regardless of the amount of sulfation, the frequency of refresh charging is more than necessary, and the electrode material is damaged, leading to deterioration of the life of the lead battery. is there.

  An object of the present invention is to provide a charge control device, a charge device, and a charge control method capable of suppressing deterioration of the life of a lead battery by performing refresh charging as necessary.

  A charge control device according to the present invention is a charge control device that controls charging of a lead battery, and includes a detection unit that detects a remaining capacity of the lead battery, and a decrease in the remaining capacity detected by the detection unit. A control unit that determines whether or not to refresh charge the lead battery based on the relationship between the amount of decrease and time.

  A charging device according to the present invention is a charging device for charging a lead battery, a detection unit for detecting a remaining capacity of the lead battery, and a decrease amount and a time when the remaining capacity detected by the detection unit is decreased. A control unit that determines whether or not the lead battery is refresh-charged based on the relationship, and a charging unit that performs refresh charging when the control unit determines that the refresh charging is performed.

  The charge control method according to the present invention is a charge control method in a charge control device for charging a lead battery, the step of detecting a remaining capacity of the lead battery, and a decrease amount when the detected remaining capacity decreases. Determining whether to refresh charge the lead battery based on the relationship with time.

  According to the present invention, it is possible to suppress deterioration of the life of the lead battery by performing refresh charging as necessary.

The block diagram which shows the structure of the charging device which concerns on embodiment of this invention The flowchart which shows the sulfation generation | occurrence | production estimation method in embodiment of this invention The flowchart which shows the charge switching method in embodiment of this invention The figure which shows the relationship between SOC and time in embodiment of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
<Configuration of charge control device>
A configuration of charging control apparatus 100 according to the embodiment of the present invention will be described with reference to FIG.

  The charge control device 100 mainly includes an SOC detection unit 101, a timer 102, a sulfation generation amount detection unit 103, a storage unit 104, and a charge control unit 105. The power reception control device 100 controls charging of the lead battery 150.

  The SOC detector 101 detects the SOC (remaining capacity) of the lead battery 150 every predetermined time. The SOC detection unit 101 sequentially outputs the SOC detection result to the sulfation generation amount detection unit 103. Here, the SOC is an index that represents the state of charge of the lead battery 150, and is a value that represents the percentage of the charge amount with respect to the full charge amount as a percentage, with the capacity at the time of full charge being 100%.

  The timer 102 measures time according to an instruction from the sulfation generation amount detection unit 103.

  The sulfation generation amount detection unit 103 obtains the relationship between the decrease amount and time when the SOC decreases from the SOC detection result input from the SOC detection unit 101 and the time measured by the timer 102.

  Specifically, the sulfation generation amount detection unit 103 causes the timer 102 to start measuring time when the SOC detection result is input from the SOC detection unit 101. The sulfation generation amount detection unit 103 obtains the SOC reduction amount from the previous and current SOC detection results, and obtains the elapsed time from the previous time to the current time from the measurement result of the time acquired from the timer 102. Then, the sulfation generation amount detection unit 103 obtains a differential value obtained by differentiating the decrease amount with the elapsed time, estimates the occurrence of sulfation from the obtained differential value, and stores the estimation result in the storage unit 104. A method for estimating the occurrence of sulfation will be described later.

  The storage unit 104 sequentially stores the estimation result of the occurrence of sulfation input from the sulfation generation amount detection unit 103.

  The charging control unit 105 reads the estimation result of the occurrence of sulfation from the storage unit 104, and performs switching control between the normal charging and the refresh charging for the charging unit 106 based on the read estimation result. Note that a charge switching method will be described later.

<Configuration of charging device>
A configuration of charging apparatus 140 in the embodiment of the present invention will be described with reference to FIG.

  The charging device 140 mainly includes the charging control device 100, the charging unit 106, and the charging connector 107. Note that the configuration of the charging control apparatus 100 has been described above, and will be omitted.

  The charging unit 106 performs normal charging or refresh charging of the lead battery 150 by accumulating electric power supplied from a power source (not shown) via the charging connector 107 in the lead battery 150 according to the control of the charging control unit 105. The charging unit 106 increases the charging current or the charging voltage when performing refresh charging as compared with when performing normal charging.

  The charging connector 107 is connected to a power source (not shown).

  The SOC detection unit 101, the timer 102, the sulfation generation amount detection unit 103, the charging control unit 105, and the charging unit 106 may be housed in one housing to constitute the charging device 140, or may be a separate housing. The charging device 140 may be configured by being housed respectively.

  The load 160 is operated by the electric power stored in the lead battery 150.

  The charging device 140 having the above configuration is, for example, a vehicle (not shown) that travels with electric power such as a HEV (Hybrid Electric Vehicle), a PEV (Plug-in Electric Vehicle), or an EV (Electric Vehicle) together with the lead battery 150 and the load 160. Can be installed.

<Sulfation occurrence estimation method>
The sulfation occurrence estimation method in the embodiment of the present invention will be described with reference to FIG.

  First, the SOC detection unit 101 determines whether or not charging is in progress (step ST201).

  If charging is being performed (step ST201: Yes), charging control apparatus 100 ends the process.

  On the other hand, when SOC is not being charged (step ST201: No), SOC detection unit 101 detects the SOC (step ST202).

  Next, the sulfation generation amount detection unit 103 calculates a decrease amount of the SOC detected last time and the SOC detected this time. Further, the sulfation generation amount detection unit 103 determines whether or not a differential value (dSOC / dt) obtained by differentiating the calculated decrease amount by the measurement waiting time M is 0 or less and larger than the threshold value α (step ST203).

  When the differential value is 0 or less and larger than the threshold value α (step ST203: Yes), the sulfation generation amount detection unit 103 adds “1” to the sulfation generation amount variable Sul and updates the sulfation generation amount variable Sul (step ST203: Yes). Sul = Sul + 1) (step ST204). Then, the sulfation generation amount detection unit 103 stores the updated sulfation generation amount variable Sul in the storage unit 104.

  Further, the charging control apparatus 100 returns the process to step 201 when the measurement waiting time M has elapsed from the previously detected time (step ST205).

  On the other hand, when the differential value is greater than 0 or less than or equal to threshold α (step ST203: No), charging control apparatus 100 skips step ST204 and proceeds to step ST205. At this time, the sulfation generation amount variable Sul stored in the storage unit 104 is not updated.

<Charging switching method>
A charge switching method in the embodiment of the present invention will be described with reference to FIG.

  First, the charging control unit 105 determines whether or not the sulfation occurrence amount variable Sul read from the storage unit 104 is larger than the threshold value β (step ST301).

  When sulfation generation amount variable Sul is larger than threshold β (step ST301: Yes), charging unit 106 performs refresh charging under the control of charging control unit 105 (step ST302).

  Next, charging section 106 determines whether or not charging has ended (step ST303).

  When charging ends (step ST303: Yes), charging device 140 ends the process.

  On the other hand, when charging is not finished (step ST303: No), charging device 140 determines whether or not charging is completed because the battery is fully charged (step ST304).

  When charging is not completed (step ST304: No), charging unit 106 returns to the process of step ST302.

  On the other hand, when charging is completed (step ST304: Yes), the charging control unit 105 resets the sulfation generation amount variable Sul stored in the storage unit 104 (step ST305), and ends the process.

  Further, in step ST301, charging unit 106 performs normal charging under the control of charging control unit 105 (step ST306) when sulfation generation amount variable Sul is equal to or less than threshold value β (step ST301: No).

  Next, charging section 106 determines whether or not charging has ended (step ST307).

  When charging ends (step ST307: Yes), charging device 140 ends the process.

  On the other hand, when charging is not finished (step ST307: No), charging device 140 determines whether or not charging is completed because the battery is fully charged (step ST308).

  When charging is not completed (step ST308: No), charging unit 106 returns to the process of step ST306.

  On the other hand, when charging is completed (step ST308: Yes), charging device 140 ends the process.

<Relationship between SOC and time>
The relationship between the SOC and time in the embodiment of the present invention will be described with reference to FIG. In FIG. 4, the SOC decreases due to use of the electric power stored in the lead battery 150 in the load 160 after time t0 to t1 and time t2, and decreases due to leaving (discharging) at time t1 to t2.

  When the lead battery 150 is not charged, as shown in FIG. 4, the SOC of the lead battery 150 gradually decreases due to use or discharge in the load 160. In general, the reduction amount of the SOC is more gradual in the decrease due to the discharge due to the standing than in the decrease in use in the load 160. The charging control apparatus 100 can estimate the sulfation occurrence section K by obtaining a differential value for each measurement waiting time M at times t1 to t2. Therefore, the charging control apparatus 100 can minimize the frequency of refresh charging by determining whether or not to perform refresh charging according to the length of the sulfation occurrence section K.

<Effect of Embodiment>
According to the present embodiment, it is possible to suppress deterioration of the life of the lead battery by performing refresh charging as necessary.

  Further, according to the present embodiment, since the SOC is detected for each measurement waiting time M and the sulfation occurrence amount variable is compared with the threshold value β, the frequency of the determination process whether to perform refresh charging is minimized. Power consumption can be reduced.

  In addition, according to the present embodiment, when the charging device and the lead battery are mounted on a vehicle, it is possible to reduce the troublesomeness such as the replacement work of the lead battery in the vehicle accompanying the deterioration of the life of the lead battery. .

<Modification of the present embodiment>
In the present embodiment, refresh charging is performed when the sulfur generation amount variable Sul is larger than the threshold value β, but the differential value obtained by differentiating the SOC reduction amount with respect to time is equal to or less than 0 and greater than the threshold value α continues for a predetermined time. At this time (for example, when K> predetermined time γ in FIG. 4), refresh charging may be performed.

  Further, in the present embodiment, the relationship between the SOC and time is obtained by differentiation (by inclination), but the relationship between the SOC and time may be obtained by a method other than differentiation.

  The charging control device, the charging device, and the charging control power method according to the present invention are suitable for controlling the charging of the lead battery.

DESCRIPTION OF SYMBOLS 100 Charge control apparatus 101 SOC detection part 102 Timer 103 Sulfation generation amount detection part 104 Memory | storage part 105 Charging control part 106 Charging part 107 Charging connector 140 Charging apparatus 150 Lead battery 160 Load

Claims (6)

A charge control device for controlling charge of a lead battery,
A detection unit for detecting the remaining capacity of the lead battery;
A control unit for determining whether to refresh charge the lead battery based on a relationship between a decrease amount and time when the remaining capacity detected by the detection unit decreases;
A charge control device. The controller is
Differentiating the amount of decrease with time to determine the relationship;
The charge control device according to claim 1. The detector is
Detecting the remaining capacity every predetermined time;
The controller is
The amount of decrease is calculated from the remaining capacity detected at the previous time and the current time by the detection unit, and a differential value obtained by differentiating the amount of decrease at a predetermined time is compared with a first threshold value. When the number of times equal to or greater than the first threshold is equal to or greater than a second threshold, the lead battery is determined to be refresh-charged;
The charge control device according to claim 1. A charging device for charging a lead battery,
A detection unit for detecting the remaining capacity of the lead battery;
A control unit for determining whether to refresh charge the lead battery based on a relationship between a decrease amount and time when the remaining capacity detected by the detection unit decreases;
A charging unit that performs refresh charging when it is determined by the control unit to perform refresh charging;
A charging device. The lead battery;
A charging device according to claim 4;
A vehicle with A charge control method in a charge control device for charging a lead battery,
Detecting the remaining capacity of the lead battery;
Determining whether to refresh charge the lead battery based on the relationship between the amount of decrease and time when the remaining capacity detected decreases; and
A charge control method.

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