JP2007159267A - Controller for storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an energy recovery efficiency by promptly increasing the temperature of a storage system up to an efficiently usable temperature without generating condensation at a secondary battery. <P>SOLUTION: An ECU executes a program including the following steps of: (S100) detecting a cabin temperature TH(A); (S200) detecting a secondary battery temperature TH(B); (S400) detecting an absolute humidity D(1) of cabin air in the case of TH(A)>TH(B) (YES in S300); (S500) detecting an absolute humidity D(2) of secondary battery-side air; and (S700) increasing the temperature of the secondary battery by operating an electric fan in the case of D(2)>D(1) (YES in S600). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a system for adjusting the temperature of a power storage mechanism such as a secondary battery mounted on a vehicle such as an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, and in particular, increases the temperature of the power storage mechanism to allow an allowable input. The present invention relates to a control device that relaxes restrictions on output power and improves fuel consumption.

  An electric vehicle, a hybrid vehicle, and a fuel cell vehicle that obtain a driving force of a vehicle with an electric motor are equipped with a secondary battery as a power source for traveling. An electric vehicle drives a motor by driving an electric motor using electric power stored in the secondary battery. A hybrid vehicle drives an electric motor using the electric power stored in the secondary battery to drive the vehicle, or assists an engine with the electric motor to drive the vehicle. A fuel cell vehicle drives a vehicle by driving an electric motor using electric power from the fuel cell, or drives an electric motor using electric power stored in a secondary battery in addition to electric power from the fuel cell. To do.

  Since these secondary batteries require high voltage and high output, for example, about 30 battery modules in which about 1.2V battery cells are connected in series are connected in series to form a battery pack. is doing. In a hybrid vehicle or the like, such a secondary battery that has not been mounted on a conventional vehicle that uses only an internal combustion engine as a drive source of the vehicle must be mounted. In vehicles, consider the mounting position of secondary batteries with a large volume among the electrical equipment mounted on the vehicle, from the viewpoint of effective use of the cabin space and cargo space, and ensuring safety in the event of a collision. There is a need. In this examination, it is necessary to consider the size of the secondary battery (height, length in the width direction of the vehicle, length in the front-rear direction of the vehicle) or the temperature of the secondary battery. There is.

  Such a secondary battery exhibits desired output performance as long as the use temperature is always within a predetermined range, and can continue to be used for a longer period of time. Therefore, conventionally, the secondary battery is warmed up to ensure the output performance of the secondary battery when the secondary battery is used in an extremely cold state, or the battery is cooled to ensure the life of the secondary battery. It is considered to be.

  Japanese Patent Application Laid-Open No. 10-252467 (Patent Document 1) discloses an electric vehicle-mounted battery temperature adjustment device that increases the efficiency of heat utilization during battery cooling or warm-up. This electric vehicle-mounted battery temperature adjusting device includes an introduction flow path from the cabin to the inside of the battery storage case, and a discharge flow path from the battery storage case to the outside of the vehicle, and is used for air conditioning of the cabin. The air that has been passed through the battery storage case cools or warms up the vehicle propulsion battery stored in the battery storage case, and discharges the air used to cool or warm up the battery. The gas is discharged out of the vehicle through the flow path, and when the gas is released from the battery, the gas is discharged out of the vehicle through the discharge flow path.

According to this battery temperature adjustment device mounted on an electric vehicle, an introduction flow path from the cabin to the inside of the battery storage case and a discharge flow path from the battery storage case to the outside of the vehicle are provided, and air used for air conditioning of the cabin is provided. It is introduced into the battery storage case through the introduction flow path, and the air used for cooling or warming up the vehicle propulsion battery stored in the battery storage case is discharged outside the vehicle through the discharge flow path. Therefore, sufficient air conditioning in the cabin and sufficient cooling / warming up of the battery can be suitably achieved, and wasteful use of energy can reduce energy waste. Furthermore, even when a battery that may release gas is used, the released gas is once accumulated in the battery storage case and then discharged to the outside of the vehicle through the discharge passage, so that the gas leaks into the cabin. The habitability is not impaired.
JP-A-10-252467

  However, the battery temperature adjustment device mounted on an electric vehicle disclosed in Patent Document 1 is merely a device for cooling or warming up a battery using air used for air conditioning of a cabin. That is, when the secondary battery is warmed up with air having a temperature higher than that of the secondary battery, condensation may occur depending on the temperature of the secondary battery.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to efficiently use the power storage mechanism without causing condensation in the power storage mechanism including a secondary battery that is a power source for traveling. An object of the present invention is to provide a control device for a power storage mechanism that can increase the energy recovery efficiency by quickly raising the temperature to a temperature that can be achieved.

  A control device for a power storage mechanism according to a first aspect of the present invention includes a supply means for supplying air in the vehicle compartment from the air inlet to the power storage mechanism, means for detecting the temperature of the air in the vehicle interior, When the temperature of the means for detecting the temperature and the temperature of the air in the vehicle interior is higher than the temperature of the power storage mechanism, the first absolute humidity is calculated based on the temperature of the air in the vehicle interior, And a calculating unit for calculating the second absolute humidity based on the control unit and controlling the supplying unit to supply air in the vehicle compartment to the power storage mechanism when the second absolute humidity is higher than the first absolute humidity. And control means.

  According to the first invention, in a power storage mechanism such as a secondary battery, when the temperature is low, the internal resistance of the secondary battery increases, the input / output power amount is limited, and the recovered energy amount during regenerative braking decreases. . For this reason, the secondary battery is warmed by the air in the passenger compartment. However, if high-humidity passenger compartment air is supplied to the low-temperature secondary battery without considering humidity, condensation occurs in the secondary battery. For this reason, comparing the absolute humidity of the passenger compartment air with the absolute humidity in the vicinity of the secondary battery, high-humidity passenger compartment air is supplied to the low-temperature secondary battery only when condensation does not occur in the secondary battery. Thus, the temperature of the secondary battery can be raised at an early stage, and the restriction on the input / output power amount can be relaxed quickly. As a result, the amount of energy recovered increases, and fuel efficiency can be improved. As a result, it is possible to quickly increase the temperature to a temperature at which the power storage mechanism can be used efficiently without causing condensation in the power storage mechanism including the secondary battery that is the power source for traveling, and to increase the energy recovery efficiency. A control device for a power storage mechanism can be provided.

  In the control device according to the second invention, in addition to the configuration of the first invention, the calculating means calculates the first absolute humidity based on the temperature and relative humidity of the air in the passenger compartment, and Means for calculating the second absolute humidity based on the temperature and the amount of saturated water vapor near the power storage mechanism are included.

  According to the second invention, the absolute humidity of the air in the passenger compartment is calculated based on the temperature and the relative humidity, and the absolute humidity on the power storage mechanism side is calculated based on the temperature and the saturated water vapor amount. Can be judged.

  In the control device according to the third invention, in addition to the configuration of the first or second invention, when the temperature of the power storage mechanism is higher than a predetermined threshold, the restriction on the input / output power amount is relaxed. It is a secondary battery.

  According to the third aspect of the invention, the internal resistance of the secondary battery is large when the temperature is low, and is small when the temperature is high. Limits can be relaxed early.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated. In the following description, a control device that controls the temperature of a secondary battery that is an example of a power storage mechanism will be described (for this reason, it will be described as a battery control device in the following), but the present invention is not limited to this. The power storage mechanism may be a capacitor instead of a secondary battery. In the following description, the vehicle is assumed to be a hybrid vehicle using an engine and a motor as drive sources, but may be an electric vehicle (EV) or a fuel cell vehicle equipped with a power storage mechanism (the power source of the EV is Not limited). Further, the mounting position of the power storage mechanism is not limited to the following description.

  FIG. 1 shows a cross-sectional view of a vehicle equipped with a battery control device according to the present embodiment. As shown in FIG. 1, this battery control device controls the temperature of a secondary battery disposed in a trunk room (a space other than the boarding space) on the vehicle rear side from the vehicle interior space (boarding space). The secondary battery is installed at a substantially central portion in the vehicle width direction so as to avoid tire houses on both sides in the vehicle width direction.

  The battery control device includes a chargeable / dischargeable secondary battery (nickel metal hydride battery or lithium ion battery) 100 that is a drive source of the vehicle, and an electric fan 200 for supplying air in the vehicle interior to the secondary battery 100. .

  In the secondary battery 100, for example, six square battery cells (usually an output voltage of about 1.2V) are connected in series to form one battery module, and a large number (20 to 30) of battery modules. Are connected in series to form a battery pack. In addition, the physique of this secondary battery 100 is a dimension which fits inside the rear side member of a vehicle width direction as an example.

  The battery control device cools the secondary battery 100 by supplying air in the vehicle interior space to the secondary battery 100 by being sucked by the electric fan 200 through the duct from the air suction port 210.

  The air inlet 210 is open to a rear package tray (usually a member on which an audio speaker or the like is installed) located at a lower part of the rear glass. That is, since the duct connected to the air suction port 210 is arranged so as to extend downward from above as shown in FIG. 1, the vehicle interior air flows downward from above as shown by the arrows in FIG. The vehicle interior air is sucked toward the secondary battery 100 by the electric fan 200 (flows between the battery modules), and then the air that has cooled the secondary battery 100 is connected to the rear of the secondary battery 100. It is discharged out of the vehicle through the duct 500.

  The ECU 1000 that realizes the battery control device according to the present embodiment includes a temperature sensor 1010 that detects the temperature in the vehicle interior, a vehicle interior temperature TH (A), and a temperature sensor 1020 that is provided in the secondary battery 100 to a secondary battery. The temperature TH (B) is input respectively. ECU 1000 controls electric fan 200 based on temperature information and the like input from each sensor. At this time, an operation command signal is output from ECU 1000 to electric fan 200.

  With reference to FIG. 2, a control structure of a program executed by ECU 1000 that realizes the battery control device according to the present embodiment will be described. Note that the program represented by this flowchart is repeatedly executed at a predetermined cycle time (for example, 80 msec).

  In step (hereinafter, step is abbreviated as S) 100, ECU 1000 detects vehicle interior temperature TH (A). At this time, the vehicle interior temperature TH (A) is detected based on a signal input from the temperature sensor 1010 to the ECU 1000.

  In S200, ECU 1000 detects secondary battery temperature TH (B). At this time, secondary battery temperature TH (B) is detected based on a signal input from temperature sensor 1020 to ECU 1000.

  In S300, ECU 1000 determines whether or not vehicle interior temperature TH (A) is higher than secondary battery temperature TH (B). If vehicle interior temperature TH (A) is higher than secondary battery temperature TH (B) (YES in S300), the process proceeds to S400. Otherwise (NO in S300), this process ends.

  In S400, ECU 1000 calculates absolute humidity D (1) from vehicle interior temperature TH (A) and relative humidity. In S500, ECU 1000 obtains a saturated water vapor amount near secondary battery 100 from secondary battery temperature TH (B), and calculates absolute humidity D (2). The absolute humidity is the amount of water dissolved as vapor in the air regardless of the temperature, and the unit is g / l, that is, the weight of water contained in 1 l of air (dry). Indicates. Relative humidity is the density or vapor pressure of saturated vapor at that temperature (the highest concentration of water that can be converted into water droplets if the amount dissolved as vapor in the air is large, but not water droplets). It is expressed by the relative ratio as 100%.

  In S600, ECU 1000 determines whether absolute humidity D (2) is higher than absolute humidity D (1). If absolute humidity D (2) is higher than absolute humidity D (1) (YES in S600), the process proceeds to S700. Otherwise (NO in S600), this process ends.

  In S700, ECU 1000 outputs an operation command signal so as to operate electric fan 200, and raises secondary battery temperature TH (B).

  The operation of the battery control device according to the present embodiment based on the above structure will be described.

  For example, when the vehicle interior temperature TH (A) is higher than the secondary battery temperature TH (B) (YES in S300), for example, in winter, the electric fan 200 is operated to force warm air in the vehicle interior. Is fed into the secondary battery 100. As a result, the temperature of the secondary battery 100 (secondary battery temperature TH (B)) increases.

  At this time, when the absolute humidity D (2) in the vicinity of the secondary battery 100 is higher than the absolute humidity D (1) in the vehicle interior (S600), even if warm air is sent to the secondary battery 100 in this way, Condensation does not occur in the battery 100. When the temperature of the secondary battery 100 rises, the internal resistance of the secondary battery 100 is large and the input / output power amount is limited at low temperatures. In such a case, the amount of energy recovered during regenerative braking is reduced.

  However, in the present embodiment, the temperature of the secondary battery 100 rises early and the restriction on the input / output power amount is eased quickly. As a result, the amount of energy recovered increases, and fuel efficiency can be improved.

  Note that the battery control device that is the control device for the power storage mechanism according to the present embodiment is particularly effective in improving fuel efficiency when the outside air temperature is a certain low temperature. Therefore, it may be added as an execution condition of S700 that the outside air temperature is lower than a predetermined threshold value.

  Furthermore, since the battery control device that is the control device of the power storage mechanism according to the present embodiment has a variation in the performance of the secondary battery when there is a temperature variation between the battery packs of the secondary battery 100, This is effective when there is little variation in temperature between battery packs. Therefore, it may be added as an execution condition of S700 that the temperature variation of the secondary battery 100 is smaller than a predetermined range.

  Further, when the vehicle is equipped with a navigation device, the process of S700 is executed on the north side of the predetermined latitude in the northern hemisphere and on the south side of the predetermined latitude in the southern hemisphere. Also good.

  As described above, according to the battery control device that is the control device of the power storage mechanism according to the present embodiment, warm air in the vehicle interior is generated without causing condensation that adversely affects the durability and performance of the secondary battery. By using it, the temperature of the secondary battery can be raised at an early stage, and the restriction on the amount of input / output power can be relaxed at an early stage. As a result, the rechargeable battery can be charged with a larger amount of regenerative electric power, so that fuel efficiency can be improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a control block diagram of the battery control apparatus which concerns on embodiment of this invention. It is a flowchart which shows the control structure of the program performed with ECU of FIG.

Explanation of symbols

  100 secondary battery, 200 electric fan, 210 cooling air inlet, 500 exhaust duct, 1000 ECU, 1010, 1020 temperature sensor.

Claims (3)

A control device for a power storage mechanism mounted on a vehicle, wherein an air intake port is provided in the vehicle interior,
Supply means for supplying air in a vehicle compartment from the air inlet to the power storage mechanism;
Means for detecting the temperature of air in the passenger compartment;
Means for detecting the temperature of the power storage mechanism;
When the temperature of the air in the passenger compartment is higher than the temperature of the power storage mechanism, the first absolute humidity is calculated based on the temperature of the air in the passenger compartment, and the second absolute is calculated based on the temperature of the power storage mechanism. A calculating means for calculating humidity;
A power storage mechanism including control means for controlling the supply means so as to supply air in the vehicle compartment to the power storage mechanism when the second absolute humidity is higher than the first absolute humidity. Control device.   The calculating means calculates the first absolute humidity based on the temperature and relative humidity of the air in the passenger compartment, and also calculates the second absolute humidity based on the temperature of the power storage mechanism and the saturated water vapor amount near the power storage mechanism. The power storage mechanism control device according to claim 1, further comprising means for calculating   The storage device control device according to claim 1 or 2, wherein the power storage mechanism is a secondary battery in which a restriction on an input / output power amount is relaxed when a temperature is higher than a predetermined threshold value.

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