JPH05111171A - Hybrid charger - Google Patents

Abstract

PURPOSE:To provide an inexpensive quick charger having high capacity efficiency. CONSTITUTION:A built-in battery 1 having voltage higher by 10-40% than that of a battery 6 to be charged is connected in parallel with a charging power supply means 2 through a circuit interrupting means 3 which functions based on the voltage difference between the batteries 1 and 6. Quick charging is realized by means of the buit-in battery 1 resulting in an inexpensive quick charger having high capacity efficiency requiring no high capacity charging power supply means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid battery charger, and more particularly to a battery charger used for rapid charging of a storage battery.

[0002]

2. Description of the Related Art A storage battery is generally charged for several hours at night except for some uses. For example, a large-capacity storage battery for an electric car or an electric car is charged for 10 hours or more at night.
This is because these storage batteries only need to be charged during the night and there is no need for quick charging.

[0003]

However, in order to improve the operating rate of electric vehicles and electric vehicles, rapid charging is absolutely necessary. For example, 50% for 1 hour break
If the capacity can be recovered, the operating rate will rise by 50%.
Also, if electric vehicles become popular, 20-
30 minutes of rapid charging is needed.

In order to rapidly charge a large-capacity storage battery, in order to reduce the charging time to 1/2 or 1/4,
The charger output current must be increased by a factor of 2, 4, etc. Inevitably, the size of the transformer and rectifier will increase, and the cost of the charger will increase. Also, the versatility of the quick charging device itself is reduced. Further, in order to increase the charging output, it is necessary to increase the capacity of the input power source. When the input current capacity is 30 to 50 A or more, special wiring work for installing the charger is required. In addition to such direct costs, we are not impressed with the rapid charging of these applications because of the operating cost that electricity costs are cheap when using late night electricity for a long time, so we dare to charge in 2-3 hours. There is not much need for a quick charging device to complete the above. However, as mentioned above, with the increasing need to improve the operating rate of electric vehicles or electric vehicles,
A rapid charger suitable for these applications will be needed.

The present invention has been made in order to solve the above problems, and its object is to be more excellent in terms of cost and volume than a conventional charger having the same performance. It is to provide a quick charger.

[0006]

Therefore, as a means for solving the above problems, the present invention comprises a built-in storage battery, a charging power supply means, and a circuit shielding means, and the built-in storage battery is better than the storage battery to be charged. The voltage is high by 10 to 40%, and is connected in parallel to the charging power supply means through the circuit shielding means for rapidly charging the battery to be charged. A hybrid for shielding the circuit of the built-in storage battery when the voltage difference between the charged storage battery and the built-in storage battery becomes equal, and the charging power supply means for charging the built-in storage battery and the charged storage battery. Adopted a charger.

[0007]

EXAMPLES The present invention will be described in detail below with reference to specific examples. FIG. 1 shows one embodiment of a hybrid charger according to the present invention. In the figure, the one-dot chain line shows the hybrid charger. 1 is a storage battery built in this charging device (hereinafter referred to as built-in storage battery), 2 is charging power supply means for charging the storage battery, 3 is circuit shielding means, 4 is voltage detection means, and 5 is a storage battery to be charged. Connection plug for,
Reference numeral 6 is a rechargeable storage battery, and 7 is an AC power connection outlet. The built-in storage battery 1 is connected in parallel to the charging power supply means 2 via the circuit shielding means 3. Circuit shielding means 3
Is for shielding the circuit of the built-in storage battery 1 when the voltage difference between the charged storage battery 6 and the built-in storage battery 1 becomes equal. The charging power supply means 2 is configured to obtain a quasi-constant voltage characteristic applying a leakage of a transformer. The feature of this system is that a large charging current can flow when the storage battery voltage during charging is low, and the charging current can be reduced as the storage battery voltage increases due to charging. The built-in storage battery 1 is for rapidly charging the charged storage battery 6, and is required to have a higher voltage than the charged storage battery 6. When the rechargeable storage battery 6 is a lead storage battery having 6 cells, the built-in storage battery 1 is preferably a lead storage battery having 7 to 8 cells. 10
In the case of a 0V 48-cell lead-acid battery, a 54-60-cell lead-acid battery is suitable. In this embodiment, a general 6-cell lead storage battery is used as the battery to be charged and a 7-cell lead storage battery is used as the built-in storage battery 1.

In order to achieve the object of the present invention, the built-in storage battery 1 must have a higher voltage than the charged storage battery 6. If it is at least 10% or more, the rechargeable storage battery 6 can be charged well. However, even if it is set too high, waste is generated from the viewpoint of cost efficiency, and the upper limit of 40% is appropriate.

FIG. 2 shows a built-in storage battery 1 in a fully charged state and a charged storage battery 6 in a discharged state in the above embodiment.
It is a figure which shows the charging characteristic in the case of. When the connection plug 5 is connected to the storage battery 6 to be charged, the voltage of the storage battery 6 to be charged is lower than the voltage of the internal storage battery 1 because the storage battery 6 to be charged is in a discharged state. Therefore, the circuit shielding means 3 is in the ON state, and due to the voltage difference between the two, a current IB flows from the built-in storage battery 1 toward the charged storage battery 6, and charging of the charged storage battery 6 is started. At this time, the charging current IC also flows from the charging power supply means 2 connected in parallel to the built-in storage battery 1 to the storage battery 6 to be charged. Now, assuming that the open circuit voltage of the built-in storage battery 1 is EA, the internal resistance is RA, the open circuit voltage of the charged storage battery 6 is EB, and the internal resistance is RB, the voltage VA immediately after the connection plug 5 is joined to the charged storage battery 6 Is given by VA = EA-IB * RA = EB + (IB + IC) * RB + [Delta] V [Delta] V is the difference voltage between the built-in storage battery 1 and the rechargeable storage battery 6 when stable. The charging current of the rechargeable storage battery 6 flowing at this time is approximately as follows. (IB + IC) = IC + (EA−EB) / (RA + RB) Since the internal resistance of RA + RB is very small, when the capacity of the built-in storage battery 1 and the rechargeable storage battery 6 is set to 500 Ah, the transient current is 300 to 400 A. Becomes This is indicated by the point X in FIG. 2, but within 1-2 seconds, discharge polarization occurs in the built-in storage battery 1 and charge polarization occurs in the charged storage battery 6, and the transient current drops to point VA, and the built-in storage battery The IB current flows at a voltage difference ΔV between the storage battery 6 to be charged. The IB current also decreases as ΔV decreases, and ΔV = 0 at the VC point, and I
The B current also becomes zero. The circuit shielding means 3 is turned off by this voltage detected by the voltage detecting means 4, and the charging current IC is not shunted to flow into the built-in storage battery 1. This indicates that the charging voltage of the rechargeable storage battery 6 has reached the open circuit voltage of the built-in storage battery 1 and the voltage difference between the two has become zero. From the point VC to the point VD, the charging voltage increases due to the IC current of the charging power supply means 2, and the rechargeable storage battery 6 can be completely charged by charging during this period. In this embodiment, since the output current of the charging power supply means 2 is set small, it takes a relatively long time.

SB in FIG. 2 indicates the quantity of electricity charged by the built-in storage battery 1, and SC indicates the quantity of electricity charged by the charging power supply means 2. This amount of electricity varies depending on the capacity of the built-in storage battery 1 and the charged storage battery 6 or the difference in the number of cells,
Similar to the above, when the capacity of both storage batteries is equivalent to 50 Ah,
Built-in storage battery 1: Charged storage battery 6 becomes about 4: 1 and VC
It can be seen that the charging time to the point is reduced to 1/5. V
The voltage at the point C is 2.35 V per cell, and normally when the charging voltage reaches this level, the capacity of the rechargeable storage battery 6 has recovered to 90%. If the charging circuit is cut off in this state, it is possible to charge the battery in a time less than 30 minutes to recover 50% of the rated capacity.

When the storage battery 6 to be charged is not connected,
The built-in storage battery 1 is charged by the charging power supply means 2.
In this case, even if the capacity of the charging power supply means 2 is small, it can be charged without delay if it takes time. Therefore, in the case of charging for a long time at night, the capacity of the charging power supply means 2 is set to the internal storage battery 1 It can be reduced to about 1/10 of the capacity. Therefore, in the case of a 50Ah storage battery, 5A
The output charging power supply means 2 is sufficient. 100A
The size of the output charger is generally about 50 x 50 x 50 cm, while the output of 5 A is 10
It becomes about 10 × 10 cm, which is very advantageous in terms of cost and space.

FIG. 3 is a modification of the expression of the characteristic diagram of FIG. 2, and the charging regulation shows the output characteristic of the charging power supply means 2. The VA point in the figure is
The internal storage battery 1 and the to-be-charged storage battery 6 are tangentially connected via the connection plug 5, and a comparatively stable state is shown after a transient state of 1 to 2 seconds has passed. Immediately, a current of about 100 A flows through the rechargeable storage battery 6 at the beginning of charging, and the voltage at that time is 13V. At this time, the sharing of the charging current is about 8A for IC and about 92A for IB. VB, VC as charging progresses
Then, IB becomes 0 at VC, and the charged storage battery 6 is charged between VC and VD in accordance with the charging regulation of the charging section.

[0013]

The hybrid charger according to the present invention is very excellent in cost and volume compared with the conventional charger having the same performance, and is widely used in electric vehicles and various electric power vehicles. Contribution Contribute.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram in one example of the present invention.

FIG. 3 is a characteristic diagram in one example of the present invention.

[Explanation of symbols]

 1 Built-in storage battery 2 Charging power supply means 3 Circuit shielding means 4 Voltage detection means 5 Connection plug 6 Charged storage battery

Claims (1)

[Claims] 1. A built-in storage battery 1, a charging power supply means 2, and a circuit shielding means 3 are provided, and the built-in storage battery 1 has a voltage higher than that of a charged storage battery 6 by 10 to 40% and a circuit shielding means. It is connected in parallel to the charging power supply means 2 via 3 and is for rapidly charging the charged storage battery 6, and the circuit shielding means 3 connects the charged storage battery 6 and the built-in storage battery 1. A hybrid charger for shielding the circuit of the built-in storage battery 1 when the voltage difference becomes equal, and for charging power supply means 2 for charging the built-in storage battery 1 and the charged storage battery 6.