JPH04125033A - Two-voltage battery - Google Patents

Abstract

PURPOSE:To get a two-voltage battery, wherein charge quantity and discharge quantity are balanced, by supplying first load with power from one of a plurality of batteries, and supplying second load with power from the plurality of batteries connected in series, and changing the battery connected to the first load over to the other battery when the output voltage of the battery has dropped below the specified value. CONSTITUTION:Batteries 11, 12, 13, and 14 are connected in series to constitute an integrated battery 1. Load 41 is connected to the battery 1. Load 43 is connected to, for example, the battery 11, and when the voltage between the positive and negative terminals of the battery 11 has dropped below the specified value, the load 43 is connected to the battery 12. Hereby, the overdischarge or the overcharge of each battery can be prevented, and the charge quantity and the discharge quantity can be balanced between each battery.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a battery for supplying voltage to a group of loads having different rated voltages, and for example, to a two-voltage battery used in a vehicle.

<Prior art> In order to reduce the weight of wiring and ensure component compatibility and longevity, a battery that supplies power with two rated output voltages (hereinafter referred to as a two-voltage battery) has been considered. There is. An example of such a battery is shown in FIG.

In FIG. 3, 811, 812. B13 and B14 are batteries each having a rated output voltage of 12 [V].

Battery Bl 1. B12. B13 and B14 are connected in series to form a battery 102 with a rated voltage of 48 [V].

A load 131 with a rated voltage of 48 [V] and a power generator 11141 are connected to the e terminal of the battery B14. Also,
A load 132 with a rated voltage of 12 [V] is connected to the ■ terminal of the battery B11, and the O terminal is grounded.

According to the above configuration, a power supply voltage of 48 [V] is applied to the load 131 by the battery 102. Further, a power supply voltage of 12 [V] is applied to the load 132 by the battery 811.

Then, the generator 141 charges the battery 102 during rest, and at the same time, the individual batteries B11. B12.
B13. B14 is also charged.

<Problem to be solved by the invention> Battery B12. B13. B14 supplies power to the load 131. Further, battery B11 supplies power to both load 131 and load 132.

Therefore, the current discharged by battery B11 is B11
Since the capacity of the load 132 is insufficient and the output voltage decreases, the load 132
There was a risk that the operation of the machine would be hindered.

On the other hand, the generator 141 causes batteries B11°B12. B
13. When charging battery B14, battery B11. B1
2. B13. Since B14 are connected in series, the current flowing through each individual becomes equal.

Therefore, when the capacity of battery 811 is insufficient, battery 812. B13. The battery 811 is not sufficiently charged within the time required to sufficiently charge B14.

Then, when battery B11 continues charging in an attempt to recover from the insufficient capacity of battery B11, battery B12. B13
．． B14 had the problem of overcharging and deteriorating durability.

In addition, battery B11. B12. Although it has been considered to charge Bl3°B14 individually, the device becomes complicated and there are practical problems.

The present invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a two-voltage battery in which charging time and discharge amount are balanced between each battery.

<Means for Solving the Problems> The present invention provides a high voltage battery configured by connecting a plurality of batteries in series, and a high voltage battery connected between the positive and negative terminals of one of the batteries constituting the high voltage battery. A second load connected between the positive and negative terminals of the high voltage battery and the positive and negative terminals of the battery to which the first load is connected are detected, and the voltage between the positive and negative terminals is detected. a voltage detecting means that outputs a switching signal when the voltage falls below a predetermined value; and a voltage detecting means that outputs a switching signal when the voltage falls below a predetermined value; The present invention is characterized by comprising a switching means for switching and connecting one load to another.

<Operation> The first load is supplied with electric power using one of the plurality of batteries as a power source. Further, the second load is supplied with power using a high voltage battery configured by connecting a plurality of batteries in series.

Further, the output voltage of the battery supplying power to the first load is detected by the voltage detection means.

Then, when the output voltage of the battery to which the first load is connected falls below a predetermined value, the first load is switched and connected to another one of the batteries constituting the high voltage battery. After that, when the output voltage of the battery to which the first load is connected drops below a predetermined value, the first load is switched and connected to one of the next batteries.

By repeating the following operations, it is possible to prevent one of the plurality of batteries from becoming over-discharged, and it is also possible to prevent each battery from being overcharged. As a result, the charging capacity and discharge amount are balanced between each battery.

<Example> FIG. 1 shows the configuration of an example of the present invention. In this example,
This is a two-voltage battery mounted on a car.

11, 12, 13, and 14 are batteries, and the rated voltage of all of them is 12 [V]. Battery 11.1
2.13.14 are connected directly and have a rated voltage of 48 [V
] constitutes a high voltage battery 1.

A negative terminal of the battery 11 is connected to one end of the relay contact 21 and is grounded. Battery 12.13.
The negative terminal of 14 is a diode 31, 32, 33, respectively.
It is connected to one end of relay contact 22, 23, 24 through.

In addition, the other ends of the relay contacts 21.22, 23.24 are connected to the first
is connected to a load 43 and a terminal 44a of a capacitor 44. The load 43 is a drive circuit for a lamp or a relay, and has a rated voltage of 12[VI. Also] Nden 1 no 44
is installed to temporarily supply power to the load 43, as will be described later.

The positive terminals of the batteries 11.12.13.14 are respectively connected to relay contacts 25.26.27.28 via diodes 34.35.36.37. The other ends of the relay contacts 25, 26, 27° 28 are connected to a load 43 and a capacitor 44.

A second load 41 such as a starter or a fan eater and a generator 42 are further connected in parallel to the positive terminal of the battery 14 . The rated voltage of the load 41 and the generator 42 is 48 [Vl.

The differential amplifiers 71, 72, 73, 74 measure the voltage between the positive and negative terminals of the battery 11, 12, 13, 14, respectively, and output a voltage signal having a value proportional to the voltage between the positive and negative terminals.

The output terminals of differential amplifiers 71, 72, 73, and 74 are A/D
It is connected to an external signal input section 51 such as a converter. The external signal input section 51 includes differential amplifiers 71.72, 73.74.
The voltage signals inputted from the MPU 52 are respectively converted into digital signals and inputted to the MPU 52.

The MPU 52 outputs a switching signal based on the digital signal. The switching signal is amplified by the external device control section 53, and then sent to the relay drive circuit 61゜62.63.64.65.
．． 66, 67, or 68.

Relay drive circuit 61. ．． 62,63.64.65°66
．． 67.68 are relay contacts 21°22.23 respectively
．． It corresponds to 24.25.26, 27.28. Then, when a switching signal is input to each relay drive circuit,
When the relay contact corresponding to the relay drive circuit is closed and no switching signal is input, the relay contact corresponding to the relay circuit is open.

Note that the voltage detection means is configured by the differential amplifiers 71, 72, 73, 74, the external signal input section 51, the MPtJ 52, and the external device control section 53, and the relay contact 21
．． 22.23.24, 25° 26.27.28 and relay drive circuit 61° 62.63, 64, 65.66.6
7.68 constitutes the switching means.

FIG. 2 is a flowchart showing the operation of the MPU 52. The operation will be explained based on FIG.

Step 300 is a state in which the ignition (not shown) is turned on, and the MPU 52 starts operating when the ignition is turned on.

In step 301, a switching signal is input to the relay drive circuits 61 and 65. Therefore, since relay contacts 21.25 in FIG. 1 are closed, load 43 and capacitor 44 are connected between the positive and negative terminals of battery 11.

Next, in step 302, it is detected whether the voltage between the positive and negative terminals of the battery 11 is equal to or higher than a predetermined value. When the determination in step 302 is YES, the capacity of the battery 11 is sufficient, and step 302 is continued until the determination is NO.

Conversely, when the determination in step 302 is No, the -1 battery 11 has insufficient capacity, and the process proceeds to step 303.

In step 303, the switching signal input to the relay drive circuits 61, 65 is stopped, and the relay contacts 21, 25
open. Then, in the next step 311, a switching signal is input to the relay drive circuits 62 and 66. Therefore, since the relay contacts 22, 26 in FIG.

The operations from step 311 to step 333 are a repetition of the operations from step 301 to step 303. However, the load 43 and capacitor 44 are
From step 11 to step 313, the battery 12 is connected, and from step 321 to step 323, the battery 13 is connected.
In step 331 to step 333, battery 1 is
Connected to 4.

Then, in step 333, the switching signal input to the relay drive circuit 64, 68 is stopped, and the switching signal input to the relay contact 24.
After opening 28, the process returns to step 301.

As described above, the batteries that supply power to the load 43 and the capacitor 44 are switched in the order of battery 11 → battery 12 → battery 13 → battery 14 → battery 11. Therefore, battery 11.12.13.14
It is possible to prevent over-discharge of each of the batteries, and also to prevent the discharge Tifi of a particular battery from becoming more than the discharge 1 of other batteries.

Meanwhile, the battery 1 is charged by the generator 42.

At this time, for example, if the capacity of the battery 11 is insufficient and the load 43 is switched to the battery 12 (if switched, the battery 1
1 has a low internal resistance.

Generally, a battery has a property that the lower the internal resistance, the faster the battery is charged, so the battery 11
is charged faster than the other batteries 12, 13, 14. As a result, the battery 11 is sufficiently charged before the load 43 is connected to the battery 11 again.

Batteries 12, 13, and 14 are also charged in the same manner.

As described above, each battery 11°12.1
3.14 is fully charged without being overcharged.

Note that in this embodiment, since a relay was used as the switching means, the batteries 11, 12, 13. or 14 and load 43
It takes 20 to 30 msl to open the relay connecting the two and close the next relay. During this time, the load 43 is not connected to any battery, but power is supplied by the capacitor 44, and the load 43
has little impact.

Also, by using semiconductor elements such as transistors and MOSFETs instead of relays as switching means,
The time required for switching can be shortened to several [ms].

As described above, according to this embodiment, the batteries 11.12 and 13.14 with a rated voltage of 12 [V] are connected in series to constitute the battery 1 with a rated voltage of 48 [V], and the battery 1 has a rated voltage of 48 [V]. Connect the load 41 of 48 [V], and the rated voltage 1
For example, a load 43 of 2 [V] is connected to the battery 11,
When the voltage between the positive and negative terminals of the battery 11 drops below a predetermined value, the load 43 is connected to the battery 12.

Therefore, it is possible to prevent the discharge current value or charging current value of a specific battery from becoming larger than that of other batteries among the batteries 11, 12, 13, 14.

As a result, it is possible to prevent over-discharging or over-charging of each battery, and it is possible to maintain a balance in the amount of charge and discharge between the batteries. Therefore, since overcharging can be prevented, the durability of the battery can be improved.

Furthermore, since power can be supplied to the load 43 with sufficient capacity, the driving of the negative W 143 can be stabilized.

<Effects of the Invention> According to the present invention, a high voltage battery is configured by connecting a plurality of batteries in series, a first load is connected to one of the plurality of batteries, and a second load is connected to the high voltage battery. load is connected, and when the voltage between the positive and negative terminals of the battery to which the first load is connected drops below a predetermined value, the first load is switched and connected to another battery.

Therefore, it is possible to prevent the discharge current value or charging current value of a specific battery from becoming larger than that of other batteries. As a result, it is possible to prevent over-discharging or over-charging, and it is possible to maintain a balance in the amount of charge and discharge between the batteries.

Therefore, it is possible to supply stable power to the first load and the second load, and the durability of the battery is improved.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the implementation of the embodiment, FIG. 2 is a flowchart showing the operation of the embodiment, and FIG. 3 is a circuit diagram showing a conventional example. 1...48 [V] Battery, 11, 12.13°1
4,...12 [V] battery, 21.22, 23°2
4.25, 26.27.28...Relay contact, 42.
...48 [V] Negative load 43...12 [V] Negative load 52
...MPU, 61,62.63.64.65°66.
67.68...Relay drive circuit, 71.72°73.
74...Differential amplifier. Figure Figure Figure

Claims (1)

[Scope of Claims] A high-voltage battery configured by connecting a plurality of batteries in series; a first load connected between the positive and negative terminals of one of the batteries constituting the high-voltage battery; A second load connected between the positive and negative terminals of the high voltage battery and a voltage between the positive and negative terminals of the battery connected to the first load are detected, and when the voltage between the positive and negative terminals becomes equal to or less than a predetermined value. , voltage detecting means that outputs a switching signal; and when the switching signal is input, switching and connecting the first load between the positive and negative terminals of another battery of the high-voltage batteries. A two-voltage battery comprising: a switching means;