JPH08186901A - Ventilating fan controller - Google Patents

Abstract

PURPOSE: To avoid the waste of battery power by driving a ventilating fan only when the battery of an assembled battery is not overcharged or not overdischarged. CONSTITUTION: When a voltage detector 3 detects that the voltage of the entire assembled battery 1 exceeds a first voltage during the charging of the battery 1 or the regenerating period of a motor 2, a fan controller 4 outputs a signal of high level. Thus, a transistor Tr and a relay 5 are turned ON to supply a voltage to a fan motor 6, and a ventilating fan exhausts hydrogen generated by overcharging out of a vehicle. Similarly, even when the voltage of the entire battery 1 drops below a second voltage, a voltage is supplied to the motor 6, and the fan exhausts the hydrogen generated by overdischarging out of the vehicle. Thus, since the hydrogen in the battery is exhausted out of the vehicle by rotating the fan only in the case of the overcharging or overdischarging, the power consumption of the battery is not wasted but the hydrogen can be efficiently exhausted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan drive control device for discharging hydrogen generated from a battery for an electric vehicle to the outside of the vehicle by using a ventilation fan.

[0002]

2. Description of the Related Art A vehicle battery is constructed by connecting a plurality of rechargeable batteries in series, and the battery is charged using a charger. On the other hand, since the running motor of the electric vehicle has the same structure as the generator, when a force is applied to the motor in a direction opposite to the driving direction, electric power (regenerative energy) is generated. Therefore, the battery can be charged by using this regenerative energy. Therefore, in the electric vehicle, both charging by the charger and charging using the regenerative energy of the motor are performed. However, the battery inside the battery has a property of generating hydrogen when overcharged or overdischarged, and it is necessary to quickly discharge the hydrogen generated from the battery to the outside of the vehicle in order to improve charging efficiency and safety.

FIG. 4 is a diagram showing a method of discharging hydrogen generated in a battery. In FIG. 4A, the ventilation fan 102 provided on the bottom side of the battery 101 discharges hydrogen in the battery to the outside of the vehicle, and the fan 102 is constantly rotated while the vehicle is running. In FIG. 4B, a discharge pipe 103 is connected to each of the batteries 101a in the battery, and hydrogen is discharged to the outside through the discharge pipe 103. In FIG. 4C, a discharge pipe 105 is provided above the battery storage case 104, and hydrogen is discharged to the outside through the discharge pipe 105. Since hydrogen is lighter than air, if a discharge pipe 105 is provided above the battery as shown in FIG. 4B or 4C, hydrogen can be discharged to the outside without providing a fan.

[0004]

However, as shown in FIG. 4 (a).
Each of the discharge methods (c) to (c) has the following drawbacks. In FIG. 4A, since the fan 102 is constantly rotated while the vehicle is traveling, the fan 102 is rotated even when hydrogen is not generated from the battery 101, and the power of the battery 101 is wastefully consumed. . Further, when the ambient temperature is low, such as in winter or late at night, the battery 10
As a result, the charge and discharge efficiency of the battery 101 may be deteriorated. On the other hand, in FIG.
Since the exhaust pipe 103 is provided for each of the batteries 101a in the battery, it is costly and the size of the entire battery becomes large. Similar to FIG. 4B, the size of the entire battery is increased in FIG.
The installation location of 04 is limited.

In order to eliminate the drawbacks of FIGS. 4A to 4C, the battery voltage V is always within a predetermined voltage range (V
_The battery voltage is controlled so that it falls within _L <V <V _H ),
It may be possible to reduce the amount of hydrogen generated from the battery, but a new circuit to control the battery voltage is required,
costly.

An object of the present invention is to provide a ventilation fan control device in which the ventilation fan is driven only when the batteries constituting the battery pack are overcharged or overdischarged so that the battery power is not wasted. Especially.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIG. 1 showing an embodiment. The present invention is generated from an assembled battery 1 constructed by connecting a plurality of rechargeable batteries in series. Ventilation fan that discharges hydrogen to the outside of the vehicle and fan drive control means 4, 5, 6, T for controlling the drive of this ventilation fan
It is applied to the ventilation fan control device equipped with r and
Is provided with overcharge / discharge detection means 3 for detecting that the battery constituting the battery has been overcharged or overdischarged.
The fan drive control means 4, 5, 6, Tr is configured to drive the ventilation fan only when it is detected that the battery is overcharged or overdischarged. Claim 2
In the ventilation fan control device according to claim 1, when the voltage of the entire battery pack exceeds the first voltage, it is determined that the battery has been overcharged, and the voltage of the whole battery pack is the first voltage. The overcharge / discharge detection means 3 is configured to determine that the battery has been overdischarged when the voltage falls below the second voltage which is lower than the voltage. According to a third aspect of the present invention, in the ventilation fan control device according to the second aspect, when the voltage of the entire assembled battery exceeds the first voltage, or the voltage of the entire assembled battery falls below the second voltage. The fan drive control means 4, so that the ventilation fan is driven for a predetermined time from the point when
5, 6 and Tr are configured. According to a fourth aspect of the present invention, in the ventilation fan control device according to the second aspect, when the voltage of the entire assembled battery once exceeds the first voltage and then falls below the first voltage, or the entire assembled battery. The fan drive control means 4, 5, 6 and Tr are configured to drive the ventilation fan for a predetermined time, starting from the time point when the voltage of 1 drops below the second voltage and then exceeds the second voltage. . The invention described in claim 5 is the invention according to claim 2.
In the ventilation fan control device described in any of 1 to 4, while the voltage of the entire battery pack exceeds the first voltage, the voltage difference between the voltage of the whole battery pack and the first voltage is continuously calculated. Then, the fan drive control means 4, 5, 6 and Tr are configured so as to determine the drive start timing and drive period of the ventilation fan based on the integrated value of the calculation results. According to a sixth aspect of the present invention, in the ventilation fan control device according to any one of the second to fourth aspects, the ventilation fan control device according to the length of the period in which the voltage of the entire battery pack exceeds the first voltage. The fan drive control means 4, 5, 6, Tr are configured so as to determine the drive start timing and the drive period.

[0008]

According to the first aspect of the invention, the ventilation fan is driven only when the batteries constituting the assembled battery 1 are overcharged or overdischarged, so that the power consumption of the battery is not wasted. According to the second aspect of the present invention, it is determined that the battery is overcharged when the voltage of the entire battery pack exceeds the first voltage, and the battery is overdischarged when the voltage of the whole battery pack is lower than the second voltage. By making a determination, it is possible to easily detect that the battery is overcharged or overdischarged. In the invention according to claim 3, the ventilation fan is driven for a predetermined time starting from a time point when the voltage of the whole battery pack exceeds the first voltage or a time point when the voltage of the whole battery pack falls below the second voltage. By doing so, the power consumption of the battery is reduced. In the invention according to claim 4, when the voltage of the whole assembled battery once falls below the first voltage after exceeding the first voltage, or when the whole assembled battery voltage falls below the second voltage, the second By driving the ventilation fan for a predetermined time starting from the time point when the voltage is exceeded, hydrogen generated by overcharging or overdischarging is efficiently discharged to the outside. In the invention according to claim 5, while the voltage of the assembled battery 1 exceeds the first voltage, the voltage difference between the entire voltage of the assembled battery and the first voltage is continuously calculated, and the calculation result Since the integrated value is further calculated, the amount of hydrogen generated can be accurately detected. In the invention according to claim 6, the drive start timing and drive period of the ventilation fan are determined according to the length of the period during which the voltage of the entire battery pack exceeds the first voltage, and the ventilation fan is determined according to the amount of hydrogen generated. To drive.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. It is not limited to.

[0010]

FIG. 1 is a block diagram of an embodiment of a ventilation fan control device. In this embodiment, an example in which the ventilation fan control device is installed in an electric vehicle will be described. In FIG.
Reference numeral 1 denotes an assembled battery which constitutes a battery, and is constituted by connecting a large number of batteries in series. Reference numeral 2 is a running motor for an electric vehicle, and 3 is a voltage detection unit for detecting the voltage of the entire assembled battery. The voltage detection unit 3 outputs a fan drive instruction signal when the voltage of the entire assembled battery exceeds the voltage V _H or falls below the voltage V _L. The voltage V _H is a voltage value indicating that the battery is overcharged, and the voltage V _L is a voltage value indicating that the battery is overdischarged.

Reference numeral 4 denotes a fan control section for controlling the drive of a ventilation fan (not shown). When a high level signal is output from the fan control section 4, the transistor Tr is turned on and a current flows through the relay 5, and its contact point. Is closed, current flows through the fan motor 6, and the ventilation fan rotates. Reference numeral 7 denotes a DC-DC converter that converts the voltage of the entire battery pack into low snow pressure and outputs the low snow pressure. The output voltage of the DC-DC converter 7 is supplied to the fan motor 6 via the relay 5.

FIG. 2 (a) is a diagram showing a temporal change in the voltage of the entire battery pack, and FIG. 2 (b) is a diagram showing a temporal change in the voltage supplied to the fan motor 6, which will be hereinafter referred to as FIG. , 2, the operation of this embodiment will be described. Figure 2 while the vehicle is running
As shown in (a), the voltage of the entire assembled battery gradually decreases. However, when the motor 2 starts the regenerative operation at the time t1, the charging current is supplied from the motor 2 to the assembled battery 1, and the voltage of the assembled battery 1 gradually increases. And
When the voltage of the assembled battery 1 exceeds the voltage V _H at time t2, the voltage detection unit 3 outputs a fan drive instruction signal. As a result, the fan control unit 4 outputs a high level signal, the transistor Tr is turned on, the contact of the relay 5 is closed, and the DC
-The output voltage of the DC converter 7 is supplied to the fan motor 6 to rotate the ventilation fan (see FIG. 2B). Then, the hydrogen existing in the battery is discharged outside the vehicle by the ventilation fan. As a result, hydrogen generated by overcharging the battery is promptly discharged outside the vehicle.

When the regenerative operation of the motor 2 is completed at the time t3, the voltage of the whole assembled battery gradually decreases. When the voltage falls below the voltage V _H at time t4, the fan drive instruction signal is no longer output from the voltage detection unit 3, and the ventilation fan stops rotating.

After time t4, the voltage of the whole assembled battery gradually decreases, and when it falls below the voltage V _L at time t5, the voltage detecting unit 3
Outputs a fan drive instruction signal again, and the ventilation fan starts rotating. As a result, even if a part of the batteries constituting the assembled battery 1 undergoes polarity reversal to generate hydrogen, the hydrogen is promptly discharged outside the vehicle by the ventilation fan. Here, the reversal means that the positive electrode and the negative electrode of the battery are exchanged. The reversal occurs when the voltage of the whole assembled battery becomes sufficiently low and the terminal voltage of some batteries becomes zero volt.In such a case, the battery that became zero volt is replaced by another battery. Is charged in the opposite direction, causing reversal,
In addition, hydrogen is generated during the reversal. However, in this embodiment, the generated hydrogen can be quickly discharged by the ventilation fan.

On the other hand, it takes a certain amount of time from the overcharging or overdischarging of each battery constituting the assembled battery 1 until the hydrogen is actually generated from each battery, and the generated hydrogen diffuses. Takes some time. Further, the amount of hydrogen generated differs depending on the time of overcharge or overdischarge. Therefore, it is necessary to control the time and the operation period when the operation of the ventilation fan is started.

FIG. 3 is a diagram showing a delay time from the output of the fan drive instruction signal from the voltage detection unit 3 to the output of the high level signal by the fan control unit 4. FIG.
(A), after the voltage across the battery pack is temporarily exceeds the voltage V _H, an example of outputting a signal of a high level only from the fan control unit 4 a predetermined time starting from the time when below the re-voltage V _H. On the other hand, FIG. 3B shows an example in which the fan control unit 4 outputs a high-level signal for a predetermined time starting from the time when the voltage of the entire assembled battery exceeds the voltage V _H. When setting the delay time, either of FIGS. 3A and 3B may be switched and selected.

In FIGS. 3 (a) and 3 (b), the length of the period during which the high level signal is output may be determined by, for example, one of the following items (1) to (3). The area of the shaded area in FIG. 3 is calculated based on the equation (1), and the high-level output period t is determined so as to be proportional to the calculated value. The shaded area in the figure indicates the voltage of the entire battery pack and the voltage V
_It represents the integrated value of the voltage difference from _H.

[Equation 1] The high-level output period is determined so as to be proportional to the length of the period in which the voltage of the entire assembled battery exceeds the voltage V _H. When the voltage of the entire assembled battery exceeds the voltage V _H , a high level signal is output for a fixed time.

Among the above-mentioned items 1 to 3, the fan motor can be driven most efficiently, but a complicated calculation is required as compared with, and therefore any one of items 1 to 3 may be arbitrarily selected depending on the time and the case.

As described above, in the above embodiment, it is detected whether the battery is overcharged or overdischarged, and only when it is overcharged or overdischarged, the ventilation fan is turned to discharge the hydrogen in the battery out of the vehicle. Therefore, hydrogen can be efficiently discharged without wasting the power consumption of the battery. Further, unlike the conventional case, it is not necessary to provide a discharge pump for discharging hydrogen, so that the cost can be reduced. Further, since it is only necessary to provide a small ventilation fan in the battery case, the entire battery case can be downsized, and the vehicle layout design becomes easy. Further, since whether the battery is overcharged or overdischarged is determined by measuring the battery voltage, it is possible to easily and accurately estimate the overcharge or overdischarge of the battery.

In FIG. 3, the method of setting the delay time when the voltage of the whole assembled battery exceeds the voltage V _H has been described. However, when the voltage of the whole assembled battery is lower than the voltage V _L , FIG. One of the methods (a) and (b) may be selected.
Further, in the above-described embodiment, an example in which a dedicated exhaust fan is provided for discharging hydrogen has been described, but it may be shared with a fan provided for other purposes such as cooling the air conditioner.

In the embodiment thus constructed, the fan control section 4, the relay 5, the fan motor 6 and the transistor Tr correspond to the fan drive control means, and the voltage detection section 3 corresponds to the overcharge / discharge detection means. To do.

[0022]

As described in detail above, according to the present invention, the ventilation fan is driven only when the batteries constituting the assembled battery are overcharged or overdischarged, so that the power consumption of the battery is wasted. Hydrogen can be efficiently discharged to the outside without being consumed. According to the invention described in claim 2, when the voltage of the whole assembled battery exceeds the first voltage, it is determined that the battery has been overcharged, and when the voltage of the whole assembled battery falls below the second voltage, the battery is over-discharged. Since it is determined that the battery has been charged, it is possible to easily and accurately determine whether the battery is overcharged or overdischarged. According to the invention described in claim 3, the ventilation fan is operated for a predetermined time starting from a time point when the voltage of the whole battery pack exceeds the first voltage or a time point when the voltage of the whole battery pack falls below the second voltage. Since it is driven, the power consumption of the battery can be reduced. According to the fourth aspect of the invention, taking into consideration that it takes a certain amount of time from when the battery is overcharged or overdischarged until hydrogen is actually generated, the voltage of the entire assembled battery is When the voltage drops below the first voltage after once exceeding the voltage of, or the voltage of the entire battery pack falls below the second voltage, the second
Since the ventilation fan is driven for a predetermined time starting from the time point when the voltage exceeds the voltage, the hydrogen generated by overcharging or overdischarging can be efficiently discharged to the outside. According to the fifth aspect of the present invention, since the drive start timing and drive period of the ventilation fan are determined by integrating the voltage difference between the entire voltage of the battery pack and the first voltage, ventilation is performed according to the amount of hydrogen generated. The drive period of the fan can be changed. Therefore, the ventilation fan can be driven more efficiently, and battery power is not wasted. According to the invention of claim 6, since the drive start timing and the drive period of the ventilation fan are determined by the length of the period in which the voltage of the entire assembled battery exceeds the first voltage,
The ventilation fan can be driven efficiently according to the amount of hydrogen generated.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a ventilation fan control device according to the present invention.

FIG. 2A is a diagram showing a temporal change in voltage of the entire assembled battery, and FIG. 2B is a diagram showing a temporal change in voltage supplied to the fan motor.

FIG. 3 is a diagram showing a delay time from the output of a fan drive instruction signal from the voltage detection unit to the output of a high level signal by the fan control unit.

FIG. 4 is a diagram showing a conventional hydrogen discharging method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery assembly 2 Motor 3 Voltage detection part 4 Fan control part 5 Relay 6 Transistor 7 DC-DC converter

Claims (6)

[Claims] 1. A ventilation fan for discharging hydrogen generated from an assembled battery constituted by connecting a plurality of rechargeable batteries in series, and a fan drive control means for controlling driving of the ventilation fan. In a ventilation fan control device comprising: an overcharge / discharge detection means for detecting that the batteries constituting the assembled battery are overcharged or overdischarged, and the fan drive control means is operated by the overcharge / discharge detection means. A ventilation fan control device, which drives the ventilation fan only when overcharge or overdischarge is detected. 2. The ventilation fan control device according to claim 1, wherein the overcharge / discharge detection unit has a first voltage of the entire assembled battery.
When the voltage of the battery pack is overcharged, it is determined that the battery is overcharged, and when the voltage of the entire assembled battery is lower than a second voltage lower than the first voltage, it is determined that the battery is overdischarged. Ventilation fan control device. 3. The ventilation fan control device according to claim 2, wherein the fan drive control unit is configured such that when the voltage of the entire assembled battery exceeds the first voltage, or when the voltage of the entire assembled battery is A ventilation fan control device, characterized in that the ventilation fan is driven for a predetermined period of time starting from a time point when the voltage falls below the second voltage. 4. The ventilation fan control device according to claim 2, wherein the fan drive control means drops below the first voltage after the voltage of the entire battery pack has once exceeded the first voltage. At the time, or the voltage of the entire assembled battery is the second
Ventilation fan control device, characterized in that the ventilation fan is driven for a predetermined period of time starting from a time point at which the second voltage is exceeded after once lowering the voltage. 5. The ventilation fan control device according to any one of claims 2 to 4, wherein the fan drive control means is configured to operate the fan assembly while the voltage of the entire battery assembly exceeds the first voltage. Ventilation fan control, characterized in that the voltage difference between the voltage of the entire battery and the first voltage is continuously calculated, and the drive start timing and drive period of the ventilation fan are determined based on the integrated value of the calculation results. apparatus. 6. The ventilation fan control device according to claim 2, wherein the fan drive control unit sets a length of a period in which the voltage of the entire assembled battery exceeds the first voltage. A ventilation fan control device characterized in that a drive start timing and a drive period of the ventilation fan are determined in accordance with the above.