JPS5826537A - Storage battery charger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a charging device for charging relatively large-capacity storage batteries used in electric vehicles and other electric vehicles, etc., in a relatively short time with a limited charging capacity. It is something.

Conventionally, charging devices for the purpose of rapid charging or high-efficiency charging have used a multi-stage charging method in which the current is switched to a lower value near the point of rapid increase in gas generation. For example, ζ is the conventional 6 in Figure 1.
Charging characteristics during fixed current charging are shown. Here, the first stage charging is performed at the battery voltage near the point where gas generation increases (in the case of lead-acid batteries,
Detects approximately 2.4■) per cell and switches to the second stage of charging, charging with the initial current of approximately A, and then in the sixth stage charging with the initial current of approximately μ. It is controlled as follows. In the above method, the second stage charging is performed at a value higher than the first stage detection voltage (approximately 2.4V) by 5V (for example, 2.4V).
A common method is to perform charging to a voltage of 6V), and then terminate charging when a preset timer time is reached. In such a charging device, the second
In order to obtain a sufficient amount of charge for each stage, it is necessary to increase the detection voltage value, the output voltage of the charging device is also required to be sufficiently high, and the amount of gas generated by the storage battery also increases, so there is a risk of inconvenience. The economy was not favorable for storage batteries either.

In addition, when the discharge amount of the storage battery to be charged differs or when the storage battery temperature changes, the amount of charge is optimized by correcting the detected voltage or changing the timer setting time each time. The settings depended largely on experience, and I was not completely satisfied with the settings.

The present invention solves the above-mentioned problems, and will be explained in detail below with reference to Examples. Figure 2 shows the basic characteristics of five-stage charging according to the present invention, where the first stage charging is constant current charging, and the second stage charging is near the detection voltage (approximately 2.4 V).
Constant voltage charging at 5th stage charging is carried out at a current value of the final value of 2nd stage charging, usually at a current of about A in the 1st stage. In this case, the voltage during the second stage charging is approximately 2
, 4V, but the same charging amount can be obtained in the same time as the conventional second stage shown in FIG. This is because the current is not reduced all at once as shown in FIG. After the second stage charging decreases to the initial charging current of about A, it switches to the fifth stage charging, and constant current charging is performed with this charging current.

With the charging device having the charging characteristics described above, there is no need to increase the output voltage of the rectifier during the second stage charging, and
During the 6th stage charging, the initial charging current is approximately A, so a somewhat higher voltage (approximately 2.6 V per city battery) is required, and there is no need to increase the capacity of the transformer or rectifying element. . Further, until the second stage charging is completed, the storage battery voltage is below the gas generation rapid point, so that unnecessary gas is not generated and the temperature of the storage battery does not rise much, making it possible to charge efficiently. Furthermore, the present invention allows the above-mentioned charging characteristics to be controlled so that the charging time of each stage is constantly maintained at an optimum state without being affected by the storage battery temperature, discharge rate, etc.

Next, an embodiment of the charging device is shown in the block diagram of FIG. ，
6 and 7 are two timer parts for charging the first, second and sixth stages respectively; 8 is a temperature detection part; 9 is a λ comparison control part which is a storage battery to be charged; The signal is compared with the reference value, and the rectifier ti2 is kept at the desired constant voltage value or constant current value, and the signals of the timer part 5.6 and 7 are compared with the set voltage and current (
The next stage of charging is switched by one of the signals from the rectifying section 2 and the timer section 5, 6,
It has the function of giving 7+. Also, between the second stage timer part 6 and the fifth stage timer part 7 (this is the fifth stage timer setting which is proportional to the second stage charging setting value or operating value). For example, when the fifth stage is C'!', the configuration switches to C'!'.Therefore, even if the battery voltage drops during charging, such as a lead-acid battery at the end of its life, the capacity will change. 100% or more of
The voltage signal is compared with the reference value of the comparison control section 5, and - constant voltage charging of about 2.4 V is performed for each cell of the rectification section 2. Note that - the second stage charging is performed until the charging current drops to about A of the second stage charging current, but the time to reach that point varies depending on the temperature of the storage battery 9 and the amount of electricity that has been discharged. .

For example, if the second stage charging time is 2 hours when the temperature is 60°C, it will be 1 hour at 45°C and 4 hours at 0°C.

Therefore, if the timer for the second stage is set to 1 hour and determined as shown in Fig. 4 based on the signal from the temperature detection section 8, the charging time for the second stage will drop to about a whisper of the charging current for the first stage. When I did,
It ends when the second stage timer part 6 reaches the time limit, and the sixth stage timer part 6 ends.
Move to step. In this way, by limiting the charging time in advance to one hour on the second stage timer, a current can be generated at the end of charging like a lead-acid battery at the end of its life, so overcharging will not occur. Also, when the temperature is different, the current drop time at the end of charging is different, but the second
Since the set time of the stage timer part 6 changes accordingly, the second stage charging is completed at an appropriate time and the process proceeds to the sixth stage charging. The 5th stage charging is set to a time proportional to the set time of the 2nd stage timer part 6 (double in Figure 4), so when this time limit is reached, charging will be completed. do. This proportionality coefficient can be determined once the current capacities of the storage battery 9 and the rectifier 2 are determined.

When the storage battery 9 is fully charged, 1 is charged at the end of the 6th stage charging.
It is best to choose a time that will allow you to achieve 20% charge. In addition, when the amount of discharge of the storage battery 9 is relatively small or when the amount of discharge varies depending on the discharge, the charging time of the fifth stage may be changed to the second stage.
By terminating charging in a time proportional to (for example, twice) the required charging time for each stage, there is an effect that even when the amount of discharge is small, the amount of charge can be made approximately 120% of the amount of discharge.

As described above, the present invention does not increase the capacity compared to conventional charging devices with constant voltage and constant current characteristics, and can shorten the charging time.Even if the battery temperature and discharge capacity are different, charging can be completed from the start to the end. In addition to being able to fully automate up to the point in time, the appropriate amount of charge can always be obtained, so the lifespan of the storage battery can be expected to be extended, and its industrial value is enormous.

[Brief explanation of the drawing]

Figure 1 is a conventional charging characteristic diagram, Figure 2 is a charging characteristic diagram according to the present invention, Figure 6 is a block diagram of a charging device according to an embodiment of the present invention, and Figure 4 is a diagram of the second stage and sixth stage. It is a temperature characteristic diagram of the timer setting of the eye. 2... Rectifier section Ro... Comparison control section 4...
Voltage and current detection section 5, 6.7... Timer part 8...
Temperature detection section 9...Storage battery applicant Yuasa Battery Co., Ltd. Figure 1

Claims (1)

[Claims] tl) It has a rectifying section that performs constant voltage constant current control, a charging positive current detecting section, and a comparison control section, and the first stage charging is constant current charging near the maximum current of the rectifying section. In the second stage charging, constant voltage charging is performed at the voltage at which the storage battery voltage has increased to the vicinity of the rapid gas generation point, and in the second stage charging, constant current charging is performed at the final current value of the second stage charging. A storage battery charging device that completes charging. (2) The patent states that the first stage charging time is switched to the second stage charging when the storage battery voltage rises near the gas generation rapid point or when the timer setting time is reached, whichever comes first. A storage battery charging device according to claim 1. (3) The second stage charging time is determined by the time when the charging current drops to about A of the maximum current of the rectifier, or when the timer setting time is reached, whichever comes first. The storage battery charging device according to claim 1, which switches to stage charging. (4) The storage battery charging device according to claim 1, wherein the second stage charging time is controlled by temperature control such that the second stage charging time is longer when the storage battery or its surrounding temperature is low and shorter when it is high. (5) The storage battery charging device according to claim 1, wherein the sixth stage charging time is the second stage charging time (the charging is completed in a time proportional to the second stage charging time).