JP2009284731A - Vehicle power supply - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the exhaust amount of an inflammable gas while reducing cost for components, and to improve safety by detecting the exhaust amount of the inflammable gas under a maintenance-free condition for a long period of time. <P>SOLUTION: A vehicle power supply includes a battery for traveling 1 to supply electric power to the motor by which the vehicle is traveled, and a gas detector 3 to detect the exhaust amount of gas exhausted by charging/discharging the battery for traveling 1. The gas detector 3 has: a detecting circuit 4 for detecting the charging/discharging condition of the charged/discharged battery for traveling 1; a memory unit 5 storing gas data to calculate the exhaust amount of an inflammable gas in the battery for traveling 1 from the charging/discharging condition of the charged/discharged battery for traveling 1; and a calculating circuit 6 to calculate the exhaust amount of the inflammable gas exhausted from the battery for traveling 1 from the charging/discharging condition of the charged/discharged battery for traveling 1, which is detected by the detecting circuit 4 and gas data stored in the memory unit 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power supply device for a vehicle that supplies electric power to a motor that is mounted on an electric vehicle and runs an automobile, and in particular, a power supply for a vehicle that detects the discharge amount of combustible gas discharged by opening a safety valve of a battery. Relates to the device.

  A power supply device for a vehicle stores a large number of rechargeable batteries in an outer case. When the battery is charged / discharged in an abnormal state, gas is generated inside the battery to increase the internal pressure of the battery. The battery is provided with a safety valve in order to prevent the internal pressure from rising and bursting. Therefore, when the internal pressure becomes abnormally high, the safety valve opens, and gas and electrolyte are discharged from the inside of the battery. In the nickel metal hydride battery and the lithium ion battery, combustible gas is discharged from the opened safety valve. The discharged combustible gas fills the outer case of the power supply device. The combustible gas accumulated in the outer case causes various adverse effects such as a reduction in safety. In order to avoid this adverse effect, a power supply device has been developed that operates a ventilation fan by providing a gas sensor in an exterior case to detect the concentration of combustible gas (see Patent Document 1).

  In this power supply device, a gas sensor that detects flammable gas is provided in an outer case that houses a fuel cell, and a ventilation fan that ventilates internal air is provided in a ventilation port provided in the outer case. This power supply device detects the concentration of combustible gas with a gas sensor, and when the concentration reaches a set value, it operates a ventilation fan to ventilate. In the power supply device with this structure, when the combustible gas is discharged from the fuel cell, the ventilation fan is operated, so that the combustible gas concentration in the outer case can be lowered to a safe concentration.

  However, in reality, a gas sensor that detects the concentration of a combustible gas, for example, a gas sensor that detects the hydrogen concentration in a nickel metal hydride battery, is extremely expensive and accurately detects the gas concentration over a long period of time. It is extremely difficult. For this reason, in order to accurately detect the concentration of the combustible gas, for example, it is necessary to replace an extremely expensive gas sensor every year, and the cost of parts becomes extremely high. For this reason, for example, it is very difficult to adopt this structure in a power supply device for a vehicle made of a nickel metal hydride battery or a lithium ion battery.

  Furthermore, a charge control device has been developed that detects the state in which gas is discharged from the lead battery from the voltage and charging time and stops charging when the gas is discharged (see Patent Document 2). Although this device can stop charging so as to prevent the generation of gas, it cannot be used safely when charging cannot be stopped normally. The vehicle power supply device controls the combustible gas not to be discharged from the traveling battery in a normal state, so that the combustible gas is not discharged. However, when a circuit for controlling charging / discharging fails and does not operate normally, the battery is charged / discharged in an abnormal state and combustible gas is discharged. Therefore, the high safety of the power supply device for vehicles cannot be guaranteed by the control for preventing the discharge of the combustible gas.

Furthermore, the power supply device can detect the discharge of the electrolyte and indirectly detect the discharge of the combustible gas. Since this power supply device indirectly detects the discharge of the flammable gas, the safety can be further improved as compared with the device of Patent Document 2 that prevents the discharge of the gas. This device detects the discharge of the electrolyte discharged together with the flammable gas with a pair of electrodes. The pair of electrodes is disposed at a position where the discharged electrolyte solution flows. When the electrolytic solution is discharged from the battery, it flows between the pair of electrodes to reduce the electrical resistance between the electrodes. Since this structure can detect the presence or absence of the electrolyte from the electrical resistance between the electrodes, the sensor can be made cheaper than the gas sensor. However, the sensor with this structure detects the discharge of the electrolytic solution, and cannot directly detect the discharge amount of the combustible gas. The opened safety valve discharges both flammable gas and electrolyte, but the discharge of flammable gas and electrolyte does not necessarily have a specific correlation, and the discharge of flammable gas is reduced by the discharge of electrolyte. It cannot be specified. For this reason, the sensor whose electrode detects the electrolyte solution can detect that the safety valve is opened and combustible gas is discharged, but cannot accurately detect the discharge amount of combustible gas.
JP-A-11-86891 JP 7-298508 A

  The present invention has been developed for the purpose of solving the conventional drawbacks. An important object of the present invention is to detect combustible gas emissions while reducing component costs, and to improve safety by detecting combustible gas emissions in a maintenance-free state over a long period of time. The object is to provide a power supply device for a vehicle.

Means for Solving the Problems and Effects of the Invention

The vehicle power supply device of the present invention has the following configuration in order to achieve the above-described object.
The power supply device for a vehicle includes a traveling battery 1 that supplies electric power to a motor that travels the vehicle, and a gas detection unit 3 that detects an amount of gas discharged by charging and discharging the traveling battery 1. The gas detection unit 3 detects the charge / discharge state of the battery 1 for traveling that is charged and discharged, and the amount of combustible gas discharged from the battery 1 for traveling from the charge / discharge state of the battery 1 that is charged / discharged. The battery 5 is discharged from the traveling battery 1 based on the storage unit 5 storing gas data to be calculated, the charge / discharge state of the traveling battery 1 detected by the detection circuit 4, and the gas data stored in the storage unit 5. And an arithmetic circuit 6 for calculating the amount of combustible gas discharged.

  The vehicle power supply apparatus described above can detect the amount of combustible gas emission while reducing component costs. This is because, instead of detecting the combustible gas with the gas sensor, the discharge amount of the combustible gas is calculated based on the gas data from the charge / discharge state of the battery. This power supply device can calculate the gas discharge amount without deteriorating like a gas sensor. For this reason, the characteristic which can detect the discharge | emission amount of combustible gas and can improve safety | security in a maintenance-free state over a long period of time is implement | achieved. In particular, the power supply apparatus described above calculates and detects the amount of combustible gas discharged, and thus has a feature that can improve safety even when the battery cannot be charged and discharged in a normal state.

In the vehicle power supply device of the present invention, the detection circuit 4 can detect the charge / discharge state from the current and voltage of the battery 2 to be charged / discharged.
This vehicle power supply device is equipped with a circuit for detecting current and voltage in order to control charging and discharging of the battery. Therefore, this power supply device can detect the amount of combustible gas discharged by using a circuit already equipped in the detection circuit without providing a special circuit for detecting the discharge of combustible gas.

In the vehicle power supply device of the present invention, the detection circuit 4 can detect the charge / discharge state from the current, voltage and remaining capacity of the battery 2 to be charged / discharged.
This power supply unit can also detect the amount of flammable gas discharged by using the circuit already equipped in the detection circuit without providing a special circuit to detect the flammable gas discharge. By detecting the charge / discharge state in consideration, the discharge amount of the combustible gas can be detected more accurately.

  The power supply device for a vehicle according to the present invention can include a plurality of unit cells 2 in which the traveling battery 1 can be charged, and an exterior case 7 that is closed and is not sealed, which houses the unit cells 2.

  Further, the power supply device for a vehicle according to the present invention includes a ventilation fan 8 connected to the outer case 7 of the traveling battery 1, and the operation of the ventilation fan 8 from the traveling battery 1 calculated by the arithmetic circuit 6. And a control circuit 9 that controls the amount of combustible gas discharged.

  Furthermore, in the vehicle power supply device of the present invention, the arithmetic circuit 6 can calculate the combustible gas concentration in the outer case 7 from the combustible gas discharge amount of the traveling battery 1.

Furthermore, the power supply device for a vehicle according to the present invention includes a ventilation fan 8 that ventilates the air in the exterior case 7 and a control circuit 9 that controls the operation of the ventilation fan 8. The control circuit 9 is an arithmetic circuit 6. The operation of the ventilation fan 8 can be controlled by the detected combustible gas concentration.
Since the power supply device operates the ventilation fan by calculating the gas concentration from the combustible gas discharge amount calculated by the arithmetic circuit, the safety can be improved by reducing the combustible gas concentration in the outer case. In particular, this power supply unit calculates the amount of flammable gas discharged from the charge / discharge state of the battery, so it does not detect the increase in the flammable gas concentration in the outer case and operate the ventilation fan. By operating the ventilation fan before the gas concentration becomes high, it is possible to reliably prevent the increase in the combustible gas concentration, and to improve safety.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below exemplifies a vehicle power supply device for embodying the technical idea of the present invention, and the present invention does not specify the vehicle power supply device as follows.

  Further, in this specification, for easy understanding of the scope of claims, numbers corresponding to the members shown in the embodiments are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  A vehicle power supply device shown in FIG. 1 includes a travel battery 1 that supplies electric power to a motor that travels the vehicle, and a gas detection unit 3 that detects the amount of gas discharged by charging and discharging the travel battery 1. With.

  The traveling battery 1 includes a plurality of rechargeable batteries 2 in an outer case 7 that is closed but not sealed. The exterior case 7 is connected to a ventilation fan 8, and the operation of the ventilation fan 8 is controlled by a control circuit 9. The battery 2 disposed in the outer case 7 is a nickel metal hydride battery, which is connected in series to increase the output voltage. However, the battery can be any battery that can be charged, such as a lithium ion battery, and can be any battery that opens a safety valve and discharges combustible gas. The ventilation fan 8 can be used in combination with a cooling fan that blows air to the battery 2 to cool it. The ventilation fan 8 exhausts the combustible gas filling the exterior case 7 to the outside, so that the outside air is forcibly blown to the exterior case 7 or the exterior case 7 is sucked and exhausted to the outside. Anything that inhales outside air can be used.

  The control circuit 9 controls the operation of the ventilation fan 8 so that the concentration of the combustible gas in the outer case 7 is lower than the set value. The combustible gas concentration in the exterior case 7 is calculated and detected by an arithmetic circuit 6 described later. Therefore, the control circuit 9 controls the operation of the ventilation fan 8 by the combustible gas concentration in the outer case 7 detected by the arithmetic circuit 6. For example, the control circuit 9 controls the operation of the ventilation fan 8 so that the combustible gas concentration in the outer case 7 is 1% or less. The control circuit 9 controls the operation and stop of the ventilation fan 8, and further controls the rotational speed of the ventilation fan 8 so that the combustible gas concentration in the outer case 7 is lower than the set value. The control circuit 9 for controlling the rotational speed of the ventilation fan 8 rotates the ventilation fan 8 at a low speed when the combustible gas discharge amount calculated by the arithmetic circuit 6 is smaller than the set value, and the combustible gas discharge amount is reduced. In a state where it exceeds the set value, the ventilation fan 8 is rotated at a high speed. Further, the control circuit 9 can increase the rotational speed of the ventilation fan 8 in proportion to the amount of combustible gas discharged. Furthermore, the arithmetic circuit 6 calculates the amount of combustible gas discharge from the charge / discharge state of the battery 2 to be charged / discharged. Since the arithmetic circuit 6 calculates the amount of combustible gas discharged in the battery 2 and detects the amount discharged from the battery 2, it can detect the amount of combustible gas discharged faster than that discharged from the battery 2. Therefore, the control circuit 9 that controls the operation of the ventilation fan 8 from the combustible gas discharge amount calculated by the arithmetic circuit 6 predicts that the combustible gas is discharged to the outer case 7 and the gas concentration becomes high, The operation of the ventilation fan 8 can be controlled.

  The conventional power supply device that detects the combustible gas concentration in the outer case by the gas sensor and controls the operation of the ventilation fan cannot theoretically eliminate the adverse effect of temporarily increasing the combustible gas concentration in the outer case. This is because the ventilation fan is operated by detecting the increase in the concentration of the combustible gas, and therefore there is a time delay for the ventilation fan to discharge the combustible gas and reduce the gas concentration.

  On the other hand, the arithmetic circuit 6 that calculates the amount of combustible gas discharged from the charge / discharge state of the battery 2 can detect the amount of combustible gas generated inside the battery 2. For this reason, it is predicted that gas will be discharged from the battery 2, and the ventilation fan 8 is operated before the gas is discharged, so that the internal air can be ventilated so that the combustible gas concentration in the outer case 7 does not increase. .

  The gas detector 3 does not detect the gas concentration of the outer case 7 with a gas sensor. The gas detector 3 calculates and detects the amount of combustible gas discharged from the state in which the battery 2 is charged and discharged. The gas detection unit 3 includes a detection circuit 4 that detects a charging / discharging state of the traveling battery 1 to be charged / discharged, and a combustible gas discharge amount of the traveling battery 1 from a charging / discharging state of the charging / discharging battery 1. From the storage unit 5 that stores the gas data for calculating the charging / discharging state of the traveling battery 1 detected by the detection circuit 4 and the gas data stored in the storage unit 5, the traveling battery 1 is discharged. And an arithmetic circuit 6 for calculating the amount of combustible gas discharged.

  The detection circuit 4 detects the current and voltage of the battery 2 constituting the traveling battery 1 and outputs a charge / discharge state for charging / discharging the battery 2 to the arithmetic circuit 6. More preferably, the detection circuit 4 detects the temperature in addition to the current and voltage, further detects the remaining capacity of the battery 2, and outputs the charge / discharge state to the arithmetic circuit 6. The vehicle power supply device includes a circuit that detects current, voltage, temperature, and remaining capacity in order to charge and discharge the battery 2 in a normal state. Therefore, the detection circuit 4 outputs a charge / discharge state composed of the current, voltage, temperature, and remaining capacity of the battery 2 to the arithmetic circuit 6 to the arithmetic circuit 6 by using a circuit already installed in the vehicle power supply device.

  The detection circuit 4 independently detects the charge / discharge state of each battery 2 constituting the battery 1 for traveling, or detects the charge / discharge states of a plurality of batteries 2 connected in series in units of modules or units. Or the charge / discharge state of the entire battery for traveling is detected and output to the arithmetic circuit 6. A power supply device using nickel-metal hydride batteries as a battery module is formed by connecting a plurality of batteries in series to form a battery module, which is connected in series to form a battery for traveling. The state can be detected, or the charge / discharge state of one unit can be detected with a plurality of battery modules as one unit. Moreover, in the power supply device which uses a lithium ion battery as a battery, the charge / discharge state of each battery connected in series is detected by a detection circuit, or a plurality of batteries are regarded as one unit, and the charge / discharge state of one unit Can be detected. In particular, the gas detector that detects the charging / discharging state of each battery or each battery module constituting the battery for traveling and outputs it to the arithmetic circuit, the arithmetic circuit determines the amount of combustible gas generated in each battery or each battery module. Since the calculation is performed from the charge / discharge state, the amount of combustible gas generated can be detected with higher accuracy.

  The memory | storage part 5 has memorize | stored the gas data for calculating flammable gas discharge | emission amount from the charging / discharging state of the battery 2 to be charged / discharged. The storage unit 5 stores gas data in order to actually charge and discharge the traveling battery 1 in a predetermined charging / discharging state and calculate the amount of combustible gas discharged in this charging / discharging state. The battery 2 is in a state where gas is generated in a specific state. Further, the amount of gas generated in a state where gas is generated is proportional to the integrated value of the current. 2 and 3 show a state in which the nickel-metal hydride battery is charged or discharged at a constant current and the voltage changes to increase the internal pressure. FIG. 2 shows the characteristics of the battery to be charged, and FIG. 3 shows the characteristics of the battery to be discharged. FIG. 2 shows a state where the internal pressure of the battery to be charged gradually increases from a specific voltage. The internal pressure of the battery is increased because gas is generated inside the battery. In other words, the internal pressure of the battery increases in proportion to the amount of gas generated. Therefore, in FIG. 2, an increase in the internal pressure of the battery indicates an increase in the amount of gas generated inside the battery. As the battery approaches full charge, the battery rises to a specific voltage and generates gas. In the nickel metal hydride battery, the battery voltage rises to the peak voltage and is fully charged, that is, the remaining capacity becomes 100%. In the figure, the internal pressure rises before the battery voltage rises to the peak voltage. That is, gas is generated inside before the battery is fully charged and the remaining capacity reaches 100%. Similarly, as shown in FIG. 3, when the voltage of the battery suddenly decreases, the internal pressure increases. That is, in the discharged battery, gas is generated from the state where the voltage is lowered to the minimum voltage, and the internal pressure is increased.

  As shown in FIG. 2, the battery to be charged is in a state where gas is generated when the voltage rises to a predetermined voltage and the remaining capacity becomes nearly fully charged, for example, when the remaining capacity exceeds 90%. From FIG. 3, the discharged battery is in a state where gas is generated when the voltage drops to a predetermined voltage and is close to complete discharge, for example, when the remaining capacity becomes 10% or less. Accordingly, the storage unit 5 has a remaining capacity (for example, 90%) at which a charged battery generates gas and a remaining capacity (for example, 10%) at which a discharged battery generates gas. The remaining gas generation capacity is stored in the gas data. Furthermore, since the gas generated in the battery is generated by a chemical reaction inside the battery (Faraday's law), the amount of gas generated is proportional to the integrated value of the flowing current. Therefore, the arithmetic circuit 6 can calculate the amount of gas generated by “current integrated value × constant”. Since this constant differs between the battery to be charged and the battery to be discharged, the storage unit 5 stores the constant for the battery being charged and the constant for the battery being discharged as gas data. Furthermore, this constant varies with the temperature of the battery. Therefore, the memory | storage part 5 has memorize | stored the constant of the charge condition with respect to temperature, and the constant in a discharge state as gas data. A power supply device that stores constants that differ depending on temperature as gas data in the storage unit 5 and corrects the temperature based on the temperature can detect the amount of combustible gas discharged from the traveling battery 1 more accurately. However, the amount of combustible gas discharged from the battery for traveling can be calculated by an arithmetic circuit without being corrected by temperature, and therefore it is not always necessary to store a constant for temperature in the storage unit.

  The gas generated inside the battery 2 raises the internal pressure of the battery 2, opens the safety valve, and discharges the gas to the outside of the battery 2. The storage unit 5 stores, as gas data, the opening pressure of the safety valve and the volume of the air gap in the battery, or the amount of valve opening gas for opening the safety valve. The internal pressure of the battery 2 is proportional to the amount of gas generated and inversely proportional to the internal volume. Therefore, in order for the internal pressure to increase to the valve opening pressure of the safety valve, it is necessary to generate a predetermined gas. In other words, the safety valve does not open until a predetermined amount of gas is generated, and the combustible gas is not discharged outside the battery 2. In order for the arithmetic circuit 6 to detect the opening of the safety valve, the storage unit 5 stores the valve opening gas amount necessary for the safety valve to open as gas data, or the valve opening pressure and the void volume are stored as gas data. It is stored as data. The power supply device that stores the valve opening gas amount in the storage unit 5 assumes that the safety valve opens when the gas amount calculated by the arithmetic circuit 6 becomes higher than the valve opening gas amount necessary to open the safety valve. Calculate flammable gas emissions. Further, in the power supply device that stores the valve opening pressure and the void volume as gas data, the arithmetic circuit 6 calculates the gas generation amount in the battery, calculates the internal pressure from the gas generation amount and the void volume, and the calculated internal pressure is opened. When the valve pressure is exceeded, the safety valve opens and the amount of combustible gas discharged is calculated.

  Further, in some batteries including a safety valve, after the safety valve is opened due to an increase in internal pressure and flammable gas is discharged, the safety valve is closed again when the internal pressure drops below a predetermined pressure. In the case of this battery, even if the safety valve is opened, not all of the internal combustible gas is discharged, and the amount of gas generated is not necessarily the amount of combustible gas discharged. This is because combustible gas that is not discharged remains in the gap of the battery when the internal pressure of the battery drops below a predetermined pressure and the safety valve is closed. Therefore, in the battery in which the opened safety valve is closed after the combustible gas is discharged, the arithmetic circuit calculates the combustible gas discharge amount by subtracting the residual gas amount from the gas generation amount. The residual gas amount can be calculated from the valve closing pressure of the safety valve and the void volume in the battery. Therefore, the storage unit stores the remaining gas amount remaining in the battery as the gas data in a state where the safety valve is closed, or stores the valve closing pressure and the void volume as the gas data. In addition, in a battery where the safety valve is not closed after the safety valve is opened due to an increase in internal pressure, even if the internal pressure drops below a predetermined pressure, all the flammable gas generated in the battery will be released when the safety valve is opened. Assume that the amount of gas generated is the amount of combustible gas discharged.

  In the power supply device that stores the gas data necessary for calculating the opening of the safety valve in the storage unit 5, the arithmetic circuit 6 can detect the opening timing of the safety valve. Therefore, the ventilation fan 8 is operated before the safety valve is opened, and the concentration of the combustible gas in the outer case 7 of the traveling battery 1 can be controlled to a low concentration more quickly. However, the power supply device does not necessarily have to store gas data for calculating the opening of the safety valve. This power supply unit stores gas data for calculating the amount of combustible gas discharged when the safety valve is opened in the storage unit, and the arithmetic circuit calculates the amount of combustible gas discharged from the charge / discharge state of the battery. To do. The storage unit uses a constant for calculating the amount of combustible gas discharge from the remaining capacity at which the battery starts to generate gas and the integrated value of current, or gas data for calculating the opening of the safety valve as a lookup table. I remember it. However, the storage unit can also store a constant for calculating the amount of combustible gas discharge and a remaining capacity as a function that varies depending on the integrated value of temperature and current.

  The arithmetic circuit 6 calculates the amount of combustible gas discharged from the traveling battery 1 from the charge / discharge state of the battery 2 input from the detection circuit 4 and the gas data stored in the storage unit 5. When the charge / discharge state of the battery 2 such as current, voltage, temperature, and remaining capacity is input from the detection circuit 4, the arithmetic circuit 6 is stored in the storage unit 5 from the input charge / discharge state of the battery 2. Based on the gas data, the combustible gas emission is calculated. The arithmetic circuit 6 calculates the amount of combustible gas discharge in the following steps shown in FIGS.

(1) Battery is charged (flow chart in FIG. 4)
[Step of n = 1]
The arithmetic circuit 6 compares the remaining capacity of the battery 2 to be charged, which is input from the detection circuit 4, with the remaining capacity of gas generation stored as gas data in the storage unit 5, for example, 90%. Determine whether the remaining capacity has been exceeded. This step is looped until the remaining capacity exceeds the remaining gas generation capacity.
[Steps n = 2, 3]
When the remaining capacity of the battery 2 exceeds the remaining gas generation capacity, integration of charging current is started. The integrated value of the charging current is calculated by integrating the charging current input from the detection circuit 4. Further, the gas generation amount is calculated from the product of the integrated value of the charging current and the constant stored in the storage unit 5. Since the integrated value of the current increases as the battery is charged, the gas generation amount is calculated from the product of the increasing integrated value and a constant.
[Step n = 4]
The calculated gas generation amount is compared with the valve opening gas amount stored in the storage unit 5, and when the gas generation amount exceeds the valve opening gas amount, it is determined that the safety valve is opened. Alternatively, the arithmetic circuit 6 determines the opening of the safety valve from the gas generation amount, the void volume of the battery 2 and the opening pressure of the safety valve. The steps of n = 2 to 3 are looped until it is determined that the safety valve is opened.
[Step n = 5]
When the safety valve is opened, the amount of combustible gas discharged from the battery 2 is calculated from the amount of gas generated calculated from the product of the integrated current value and the constant. In a battery in which the opened safety valve is closed after flammable gas is discharged, the calculation circuit calculates the amount of flammable gas discharged by subtracting the amount of residual gas remaining in the battery after closing the valve from the amount of gas generated. To do. In addition, in a battery in which the opened safety valve is not closed even after the internal pressure is reduced, the arithmetic circuit sets the amount of gas generated in the battery as the amount of combustible gas discharge.

(2) Battery is discharged (flow chart in FIG. 5)
[Step of n = 1]
The arithmetic circuit 6 compares the remaining capacity of the discharged battery 2 input from the detection circuit 4 with the remaining gas generation capacity stored as gas data in the storage unit 5, for example, 10%. It is determined whether or not the generated remaining capacity is reached. This step is looped until the remaining capacity becomes smaller than the remaining gas generation capacity.
[Steps n = 2, 3]
When the remaining capacity of the battery 2 becomes smaller than the remaining gas generation capacity, integration of charging current is started. The integrated value of the charging current is calculated by integrating the charging current input from the detection circuit 4. Further, the gas generation amount is calculated from the product of the integrated value of the charging current and the constant stored in the storage unit 5. Since the integrated value of the current increases with discharge, the gas generation amount is calculated from the product of the increasing integrated value and a constant.
[Step n = 4]
The calculated gas generation amount is compared with the valve opening gas amount stored in the storage unit 5, and when the gas generation amount exceeds the valve opening gas amount, it is determined that the safety valve is opened. Alternatively, the arithmetic circuit 6 determines the opening of the safety valve from the gas generation amount, the void volume of the battery 2 and the opening pressure of the safety valve. The steps of n = 2 to 3 are looped until it is determined that the safety valve is opened.
[Step n = 5]
When the safety valve is opened, the amount of combustible gas discharged from the battery 2 is calculated from the amount of gas generated calculated from the product of the integrated current value and the constant. In batteries where the opened safety valve is closed after flammable gas is discharged, the arithmetic circuit calculates the amount of flammable gas discharged by subtracting the amount of residual gas remaining in the battery after closing the valve from the amount of gas generated. To do. In addition, in a battery in which the opened safety valve is not closed even after the internal pressure is reduced, the arithmetic circuit sets the amount of gas generated in the battery as the amount of combustible gas discharge.

Further, the arithmetic circuit 6 controls the operation of the ventilation fan 8 by calculating the combustible gas concentration in the outer case 7 from the combustible gas discharge amount in the following flowchart shown in FIG.
[Steps n = 1 to 3]
It is determined whether the safety valve is opened. When the safety valve is opened, the ventilation fan 8 is operated weakly. If the safety valve is not opened, the operation of the ventilation fan 8 is stopped and this step is looped.
[Steps n = 4-6]
When the safety valve is opened and combustible gas is discharged from the traveling battery 1, the combustible gas concentration in the outer case 7 is calculated from the combustible gas discharge amount, and the calculated combustible gas concentration is If it is lower than the set value, the ventilation fan 8 is operated weakly.
[Steps of n = 7, 8]
When the combustible gas concentration in the outer case 7 becomes higher than the set value, the contactor of the traveling battery 1 is switched off to cut off the current and stop the vehicle, and the ventilation fan 8 is operated at the maximum air volume, The combustible gas is forcibly discharged from the case 7.

  The above power supply device detects the valve opening of the safety valve and operates the ventilation fan 8. The power supply device of the present invention calculates the flammable gas concentration of the outer case 7 from the flammable gas discharge amount, and is calculated. When the combustible gas concentration rises to the set concentration, the operation of the ventilation fan 8 can be started. Further, as the flammable gas concentration in the outer case 7 calculated from the flammable gas discharge amount increases, the rotation of the ventilation fan 8 is made faster so that the amount of flammable gas forcibly discharged from the outer case 7 is increased. Increasing the gas concentration in the outer case 7 can be more reliably prevented.

  Further, the above power supply device stores the remaining gas generation capacity and constants as gas data in the storage unit 5 and calculates the combustible gas discharge amount from these gas data by the arithmetic circuit 6. The unit 5 can store gas data that can directly calculate the amount of combustible gas discharge from the current, voltage, temperature, remaining capacity, etc. of the battery 2, and the arithmetic circuit 6 can also calculate the amount of combustible gas discharge. Therefore, the power supply device of the present invention does not specify the gas data to be stored in the storage unit 5 as the remaining gas generation capacity or the constant, but from the charge / discharge state of the battery 2 input from the detection circuit 4, the arithmetic circuit 6. Can be all data that can calculate the amount of combustible gas emission.

It is a schematic block diagram of the power supply device for vehicles concerning one Example of the present invention. It is a graph which shows the relationship between the voltage of a nickel metal hydride battery charged with a fixed electric current, and an internal pressure rise. It is a graph which shows the relationship between the voltage of a nickel hydride battery discharged with a fixed electric current, and an internal pressure rise. It is a flowchart in which an arithmetic circuit calculates combustible gas discharge | emission amount in the state in which a battery is charged. It is a flowchart in which an arithmetic circuit calculates combustible gas discharge | emission amount in the state in which a battery is discharged. It is a flowchart which calculates the combustible gas density | concentration of an exterior case from combustible gas discharge | emission amount, and controls the driving | operation of a ventilation fan.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery for driving | running | working 2 ... Battery 3 ... Gas detection part 4 ... Detection circuit 5 ... Memory | storage part 6 ... Arithmetic circuit 7 ... Exterior case 8 ... Ventilation fan 9 ... Control circuit

Claims (7)

For a vehicle comprising a traveling battery (1) for supplying electric power to a motor for traveling the vehicle, and a gas detection unit (3) for detecting the amount of gas discharged by charging and discharging the traveling battery (1) Power supply unit,
The gas detection unit (3) detects the charge / discharge state of the battery (1) for traveling to be charged / discharged, and the battery for traveling from the charge / discharge state of the battery (1) for charge / discharge. A storage unit (5) storing gas data for calculating a combustible gas discharge amount of the battery (1), a charge / discharge state of the battery (1) for traveling detected by the detection circuit (4), and storage A vehicle power supply device comprising: an arithmetic circuit (6) for calculating an amount of combustible gas discharged from the traveling battery (1) from gas data stored in the section (5).   The power supply device for a vehicle according to claim 1, wherein the detection circuit (4) detects a charge / discharge state from a current and a voltage of the battery (2) to be charged / discharged.   The power supply device for a vehicle according to claim 1, wherein the detection circuit (4) detects a charge / discharge state from the current, voltage and remaining capacity of the battery (2) to be charged / discharged.   The travel battery (1) comprises a plurality of unit cells (2) that can be charged, and an outer case (7) that houses the unit cells (2) but is closed but not sealed. The vehicle power supply described.   The ventilation fan (8) connected to the exterior case (7) of the battery for traveling (1), and the battery for traveling (1) calculated by the arithmetic circuit (6) for the operation of the ventilation fan (8). And a control circuit (9) that controls the amount of combustible gas discharged from the vehicle.   The vehicle power supply device according to claim 4, wherein the arithmetic circuit (6) calculates a combustible gas concentration in the outer case (7) from a combustible gas discharge amount of the traveling battery (1).   A ventilation fan (8) for ventilating the air in the outer case (7), and a control circuit (9) for controlling the operation of the ventilation fan (8), the control circuit (9) is the arithmetic circuit ( The power supply device for a vehicle according to claim 6, wherein the operation of the ventilation fan (8) is controlled by the combustible gas concentration detected in 6).

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