JP2006139963A - Battery cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery cooling device capable of maintaining a battery temperature in an appropriate temperature range.
A battery cooling device 1 sets a high-voltage battery 12 mounted on a vehicle, a cooling fan 18 that cools the high-voltage battery 12, a travel route of the vehicle, and road information related to the set travel route. And the car navigation system 30 for acquiring road traffic information, the temperature sensor 14 for detecting the temperature of the high voltage battery, the high voltage when the vehicle travels on the travel route based on the battery temperature Tb, road information, and road traffic information. A BATT ECU 10 that predicts the temperature of the battery 12 and drives the cooling fan when the predicted battery temperature Tbf is predicted to be equal to or higher than a predetermined temperature Tmax is provided.
[Selection] Figure 1

Description

  The present invention relates to a battery cooling device, and more particularly to a vehicle battery cooling device.

In general, a battery has a significant decrease in performance and a lifetime when it is heated to a high temperature. Therefore, conventionally, a battery cooling device that suppresses a temperature rise due to heat generation of the battery by introducing outside air into the battery housing chamber when the battery is hot to cool the battery and prevents a decrease in performance and life has been used. (For example, refer to Patent Document 1).
JP-A-9-275601

  However, since a large-capacity battery used in a hybrid vehicle or the like has a large heat capacity and is difficult to cool, the temperature does not drop immediately even when cooling is started. Further, since cooling is performed from the outside of the battery, there is a time delay until the inside of the battery is cooled. Therefore, for example, in a traveling state in which charging / discharging is frequently performed, the battery temperature may rise beyond the appropriate temperature range due to heat generated by charging / discharging.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a battery cooling device that can maintain the temperature of the battery in an appropriate temperature range.

  A battery cooling device according to the present invention includes a battery mounted on a vehicle, cooling means for cooling the battery, travel route setting means for setting a travel route of the vehicle, and information on the travel route set by the travel route setting means. When it is predicted that the temperature of the battery when traveling on the travel route will be equal to or higher than a predetermined temperature based on the travel route information acquired by the travel route information acquisition means and the travel route information acquisition means. And a control means for driving the means.

  According to the battery cooling device of the present invention, when it is predicted that the battery temperature will rise above a predetermined temperature based on the travel route information related to the set travel route, the cooling means is driven to lower the battery temperature in advance. It is done. As a result, the temperature of the battery can be maintained in an appropriate temperature range.

  The battery cooling device according to the present invention is preferably a car navigation system in which the travel route information acquisition unit guides the vehicle to the destination, and the travel route information is physical information of roads constituting the travel route. .

  In this case, physical information on the road, for example, whether the road is flat, uphill or downhill, road gradient, curvature, traffic light arrangement, and the like are obtained from the car navigation system. Therefore, the battery temperature when traveling along the travel route can be predicted based on these pieces of information.

  In addition, it is preferable that the travel route information acquisition unit further includes a road traffic information communication system that acquires road traffic information from outside the vehicle, and the travel route information includes road traffic information of the road.

  In this case, road traffic information on the travel route, for example, traffic jam information, construction information, and the like can be obtained from the road traffic information communication system. Therefore, it is possible to predict the battery temperature when the vehicle travels on the travel route in consideration of road traffic information in addition to physical road information. As a result, the battery temperature can be predicted more accurately.

  The battery cooling device according to the present invention includes a battery temperature acquisition unit that acquires the temperature of the battery, and the battery temperature when the vehicle travels along the travel route based on the battery temperature and the travel route information acquired by the battery temperature acquisition unit. It is preferable that a battery temperature prediction unit for prediction is provided, and the control unit drives the cooling unit when the battery temperature predicted by the battery temperature prediction unit is predicted to be equal to or higher than a predetermined temperature.

  In this case, since the battery temperature when traveling on the set travel route is predicted from the actual battery temperature acquired by the battery temperature acquisition means and the travel route information, the battery temperature can be predicted more accurately. it can. And since the drive of a cooling means is controlled based on this battery estimated temperature, it becomes possible to hold | maintain the temperature of a battery more appropriately in a suitable temperature range.

  In the battery cooling device according to the present invention, the battery temperature predicting means predicts the charge / discharge amount of the battery when traveling on the travel route based on the travel route information, and the battery temperature according to the charge / discharge amount. Is preferably predicted.

  In this case, the charge / discharge amount of the battery when traveling on the travel route based on the travel route information is predicted, and the heat generation amount of the battery is obtained from the predicted charge / discharge amount. Since the battery rising temperature is calculated from the heat generation amount of the battery and the heat capacity of the battery, which is a known value, the battery temperature can be predicted.

  According to the present invention, when the battery temperature is predicted to be equal to or higher than the predetermined temperature, the cooling unit is driven to reduce the battery temperature in advance, so that the battery temperature can be maintained in an appropriate temperature range. Become.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts.

  First, the overall configuration of the battery cooling device according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing an overall configuration of a battery cooling device 1 that cools a high-voltage battery 12 mounted on a hybrid vehicle.

  The hybrid vehicle is equipped with a hybrid system that uses the engine 42 that is an internal combustion engine and the electric motor 24 in combination. This hybrid system has three modes: a mode that travels using the power of the engine 42, a mode that generates power using the power of the engine 42 and travels using the electric motor 24, and a mode that travels using only the electric motor 24 with the engine 42 stopped. . These three driving modes are switched so as to be most efficient according to the driving state of the vehicle.

  For example, the start is performed only by the driving force of the electric motor 24, and when the engine reaches a traveling state with good engine efficiency, the engine 42 is switched to traveling. During traveling, the power distribution between the electric motor 24 and the engine 42 is adjusted to be optimum according to the traveling state. When a large driving force is required, such as during acceleration, both the engine 42 and the electric motor 24 are driven.

  Further, at the time of braking, the electric motor 24 is rotated by the power transmitted from the wheels to operate as a generator, and the kinetic energy is converted into electric energy and collected in the high voltage battery 12.

  The electric motor 24 is an AC synchronous motor and is driven by AC power output from the inverter 22. Further, as described above, the electric motor 24 can also generate power (regenerative power generation) using power from the wheels.

  Each of the electric motor 24 and the engine 42 is controlled by a hybrid system electronic control unit (hereinafter referred to as “HV ECU”) 20 and an engine electronic control unit (hereinafter referred to as “EFI ECU”) 40.

  Each of the HV ECU 20 and the EFI ECU 40 is stored by a microprocessor that performs calculations therein, a ROM that stores programs for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, and a 12V battery. It has a backup RAM for storing the contents.

  The HV ECU 20 is connected to an accelerator position sensor 26 that detects the accelerator opening, a shift position sensor 27 that detects a shift position of the transmission, and the like.

  The HV ECU 20 calculates the required driving force requested by the driver based on the accelerator opening, the shift position, and the like. The HV ECU 72 sets target outputs of the electric motor 24 and the engine 42 according to the required driving force, the state of charge of the high-voltage battery 12 (hereinafter referred to as “SOC: State of Charge”), the traveling state of the vehicle, and the like. The set target engine output is output to the EFI ECU 40.

  The EFI ECU 40 controls the operation of the engine 21 by adjusting the intake air amount, the fuel injection amount, and the like based on the input target engine output.

  On the other hand, the HV ECU 20 controls the operation of the electric motor 24 based on the set target motor output. More specifically, the HV ECU 20 is connected to a resolver 28 that detects the rotational speed of the electric motor 24, a current sensor 29 that detects a phase current flowing through the three-phase wire 23, and the like. The electric motor 24 is driven by performing switching control of the inverter 22 based on the input signal from and the set target motor output.

  The inverter 22 converts electric power stored in the high voltage battery 12 from direct current to alternating current based on a switching signal from the HV ECU 20 and supplies the electric power to the electric motor 24. Further, the electric power regenerated by the electric motor 24 is converted from alternating current to direct current and stored in the high voltage battery 12.

  The high-voltage battery 12 is formed by connecting, for example, 28 battery modules 12A (see FIG. 2) in which six 1.2V cells are connected in series, for a total of 168 cells. Therefore, a high voltage of 210.6V is secured. The high voltage battery 12 is housed in the battery pack 13 together with the system main relay and the like and mounted on the vehicle.

  The high voltage battery 12 is repeatedly discharged by regenerative braking when the vehicle is accelerated and the like, and is recharged by regenerative braking. Therefore, the battery electronic control unit (hereinafter referred to as “BATT ECU”) 10 manages the SOC within an appropriate range. .

  The BATT ECU 10 is similar to the HV ECU 20 and the like, and is stored by a microprocessor that performs calculations, a ROM that stores a program for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, and a 12V battery. It is composed of a backup RAM or the like that holds the contents.

  Further, the BATT ECU 10 includes a temperature sensor 14 that detects the temperature of the high-voltage battery 12, a voltage sensor 15 that detects the voltage of the high-voltage battery 12, a current sensor 16 that detects the charge / discharge current of the high-voltage battery 12, and the like. It is connected. The temperature sensor 14 functions as battery temperature acquisition means.

  The BATT ECU 10 detects the SOC by integrating the detected charge / discharge currents, and outputs the SOC to the HV ECU 20 so that the SOC is maintained within the control target range. Further, the BATT ECU 10 monitors the detected temperature and voltage of the high voltage battery 12 and protects the high voltage battery 12 by stopping charging / discharging when an abnormality is detected.

  The BATT ECU 10 controls the driving of the cooling fan 18 according to the temperature of the high voltage battery 12 in order to ensure the battery performance against the heat generated by charging / discharging of the high voltage battery 12, and the temperature of the high voltage battery 12 is controlled. Adjust to an appropriate range.

  Further, the BATT ECU 10 predicts the charge / discharge amount of the high-voltage battery 12 when traveling along this travel route based on road information and road traffic information of the travel route input from the car navigation system 30 described later. Based on the calorific value obtained from the predicted charge / discharge amount and the battery temperature detected by the temperature sensor 14, the battery temperature when traveling along this travel route is predicted. When the predicted battery temperature (hereinafter referred to as “battery predicted temperature”) is predicted to rise above a predetermined temperature, the cooling fan 18 is driven. That is, the BATT ECU 10 functions as battery temperature prediction means and control means.

  In the present embodiment, an air-cooling cooling method is employed in which the cooling fan 18 cools the high voltage battery 12 by flowing cooling air into the battery pack 13 in which the high voltage battery 12 is housed. That is, the cooling fan 18 functions as a cooling unit. FIG. 2 shows a flow of cooling air for cooling the high voltage battery 12. The suction port of the intake duct 62 is installed on the right side of the rear seat, for example. The air taken in from the passenger compartment by the cooling fan 18 is introduced from the upper side of the battery pack 13 through the intake duct 62, and is caused to flow between the battery modules 12 </ b> A constituting the high voltage battery 12 from the top to the bottom, thereby causing the high voltage battery. 12 is cooled. The air heat-exchanged by cooling passes through the exhaust duct 66 from the lower side of the battery pack 13 and is discharged into the trunk room and outside the vehicle.

  The hybrid vehicle includes a car navigation system 30 that guides the vehicle to a destination. The car navigation system 30 of this embodiment is a system that uses a GPS (Global Positioning System) and a road traffic information communication system (VICS), and is an electronic control device for a car navigation system (hereinafter referred to as “NAVI ECU”). ”).

  The NAVI ECU 32 detects the vehicle position based on the GPS satellite signal received by the GPS receiver 34. The travel distance is calculated based on the vehicle speed signal, and the vehicle traveling direction is detected according to the signal from the gyro sensor.

  On the other hand, the VICS receiver 36 acquires road traffic information provided from the VICS center using radio wave beacons, optical beacons, and FM multiplex broadcasting. The types of road traffic information include, for example, traffic jams, accidents, construction regulations, required time, and highway entrance closure information. The road traffic information acquired from the VICS center is output to the NAVI ECU 32.

  The NAVI ECU 32 outputs the map information read by the DVD-ROM player, the calculated vehicle position, road traffic information, and the like to the display 38. The display 38 displays map information, road traffic information, and the like input from the NAVI ECU 32 using graphics and characters.

  In the car navigation system 30, when a destination is set, a route search is executed and a travel route from the current point to the destination is set. Even when the destination is not set, for example, when traveling on a single road such as an expressway, this road may be set as the travel route. Further, physical information (road information) of roads constituting the set travel route, for example, flat roads, uphill roads, downhill roads, road gradients, curvatures, traffic light arrangements, and the like are acquired. That is, the car navigation system 30 functions as a travel route setting unit and a travel route information acquisition unit. The acquired road information, road traffic information, own vehicle position, and the like of the travel route are output to the HV ECU 20.

  The BATT ECU 10, the HV ECU 20, the NAVI ECU 30, and the EFI ECU 40 are connected via a communication line 50 such as a CAN (Controller Area Network), for example, and are configured to be able to exchange data with each other. .

  Next, the operation of the battery cooling device 1 will be described with reference to FIG. Here, FIG. 3 is a flowchart showing a processing procedure (first control mode) of cooling control of the high-voltage battery 12 by the battery cooling device 1. This process is performed by the BATT ECU 10, and is repeatedly executed at a predetermined timing from when the power of the BATT ECU 10 is turned on to when it is turned off.

  In step S100, road information such as the road gradient and curvature of the set travel route is read from the car navigation system 30. In the subsequent step S102, the battery temperature Tb and the battery voltage Vb of the high voltage battery 12 are read. Next, in step S104, based on the road information read in step S100, the charge / discharge amount Cb of the high voltage battery 12 when traveling on the set travel route is predicted.

  Subsequently, in step S106, the battery temperature Tb, the battery voltage Vb read in step S102, and the amount of heat generated according to the charge / discharge amount Cb of the high voltage battery 12 predicted in step S104 are set. The battery temperature when traveling along the travel route is predicted. For example, when traveling on a road that continues up and down, for example, the assist amount and the regeneration amount of the electric motor 24 increase and the charge / discharge amount Cb of the high voltage battery 12 increases, so that the heat generation amount increases and the battery temperature increases. Tb rises.

  In subsequent step S108, a determination is made as to whether or not the battery temperature predicted in step S106 (hereinafter referred to as “battery predicted temperature Tbf”) rises above a predetermined temperature Tmax (eg, 60 ° C.). Here, when it is determined that the predicted battery temperature Tbf does not rise above the predetermined temperature Tmax, the process is temporarily exited. On the other hand, when it is determined that the predicted battery temperature Tbf rises above the predetermined temperature Tmax, the process proceeds to step S110.

  In step S <b> 110, a cooling start point and a cooling start time for executing control for lowering the temperature in advance (hereinafter referred to as “predictive cooling control”) before the temperature of the high voltage battery 12 rises are set. More specifically, the ROM of the BATT ECU 10 defines the relationship between the battery temperature Tb of the high voltage battery 12, the distance to the point where the charge / discharge amount Cb of the high voltage battery 12 increases, and the cooling start point. A map (cooling start point map) is stored. And a cooling start point map is searched by battery temperature Tb and charging / discharging amount increase point, and a cooling start point is calculated | required. As shown in FIG. 4, the cooling start point map is set so that the cooling start point becomes closer to the vehicle position as the battery temperature Tb increases. Further, the cooling start point is set to be farther from the vehicle position as the distance to the point where the charge / discharge amount Cb increases. Further, the cooling start time is obtained from the distance from the vehicle position to the cooling start point and the average vehicle speed.

  In step S112, it is determined whether or not the flag F_YOSOKU indicating that the predicted cooling control is being executed is turned on, that is, whether or not the predicted cooling control is being executed. Here, when the flag F_YOSOKU is on, that is, when the predictive cooling control is being executed, the process proceeds to step S126. On the other hand, when the flag F_YOSOKU is off, that is, when the predictive cooling control is not being executed, the process proceeds to step S114.

  In step S114, it is determined whether or not the battery temperature Tb is higher than a predetermined temperature Tmin1 (for example, 8 ° C.). If the battery temperature Tb is higher than the predetermined temperature Tmin1, the process proceeds to step S116. On the other hand, when the battery temperature Tb is equal to or lower than the predetermined temperature Tmin1, that is, when the temperature of the high voltage battery 12 is already low, the process proceeds to step S122.

  In step S116, a determination is made as to whether or not the cooling start point set in step S110 has been reached or whether or not the cooling start time has elapsed. Here, when the cooling start point has been reached or when the cooling start time has elapsed, the flag F_YOSOKU is turned on in step S118, and the cooling fan 18 is driven in the subsequent step S120, whereby the high-voltage battery. 12 is cooled. Thereafter, the process is temporarily exited.

  On the other hand, if the cooling start point has not yet been reached and the cooling start time has not elapsed, the flag F_YOSOKU is turned off in step S122, and the cooling fan 18 is stopped in the subsequent step S124. Thereafter, the process is temporarily exited.

  When the flag F_YOSOKU is on in step S112, that is, when the predictive cooling control is being executed, in step S126, it is determined whether or not the battery temperature Tb is higher than a predetermined temperature Tmin2 (for example, 5 ° C.). If the battery temperature Tb is higher than the predetermined temperature Tmin2, the flag F_YOSOKU is turned on in step S128, and the cooling fan 18 is driven in the subsequent step S130, so that the predicted cooling control is continuously executed. . Thereafter, the process is temporarily exited.

  On the other hand, when the battery temperature is equal to or lower than the predetermined temperature Tmin2, that is, when the temperature of the high voltage battery 12 has sufficiently decreased, the flag F_YOSOKU is turned off in step S132, and the cooling fan 18 is stopped in the subsequent step S134. Predictive cooling control is stopped. Thereafter, the process is temporarily exited.

  Here, FIG. 5 shows an example of the battery temperature change when the predicted cooling control is performed. Based on road information and road traffic information, for example, when it is predicted that the charge / discharge amount Cb will increase after time t2 and the battery temperature Tb will rise above the predetermined temperature Tmax (see the alternate long and short dash line), at time t1 The cooling fan 18 is driven in advance, and the temperature of the high voltage battery 12 is lowered in advance. Therefore, even if the charge / discharge amount Cb increases after time t2 and the heat generation amount of the high voltage battery 12 increases, the battery temperature Tb is held in an appropriate temperature range equal to or lower than the predetermined temperature Tmax.

  According to the present embodiment, the predicted battery temperature Tbf is obtained from the charge / discharge amount Cb of the high-voltage battery 12 predicted based on road information such as the gradient and curvature of the road constituting the travel route, and this predicted battery temperature Tbf. Is predicted to rise above the predetermined temperature Tmax, the cooling fan 1 is driven to lower the battery temperature Tb in advance. As a result, the temperature of the high voltage battery 12 can be maintained in an appropriate temperature range.

  In addition to the road information of the set travel route, the charge / discharge amount Cb of the high voltage battery 12 and the predicted battery temperature Tbf can be obtained by further considering the VICS road traffic information, and the driving of the cooling fan 18 can be controlled. (Second control mode). Next, the second control mode will be described with reference to FIG. FIG. 6 is a flowchart showing another processing procedure (second control mode) for predictive cooling control by the battery cooling device 1. This process is also performed by the BATT ECU 10, and is repeatedly executed at a predetermined timing from when the power of the BATT ECU 10 is turned on to when it is turned off.

  In step S200, road information such as the gradient and curvature of the roads constituting the travel route is read, and road traffic information such as traffic jams and accidents is read. Subsequently, in step S202, the battery temperature Tb and the battery voltage Vb of the high voltage battery 12 are read.

  In subsequent step S204, based on the road information and road traffic information read in step S200, the charge / discharge amount Cb of the high-voltage battery 12 when traveling on the set travel route is predicted. For example, when there is a traffic jam on the travel route scheduled to travel ahead, start, acceleration, and braking (regeneration) are frequently repeated, and the charge / discharge amount Cb of the high-voltage battery 12 increases. To do.

  Since the processing content in steps S206 to S234 is the same as the processing content in steps S106 to S134 described above, description thereof is omitted here.

  According to the present embodiment, the battery temperature Tb when the vehicle travels on the set travel route is predicted in consideration of road traffic information such as traffic congestion and accidents in addition to road information such as road gradient and curvature. . Therefore, since the battery temperature Tb can be predicted more accurately, the temperature of the high-voltage battery 12 can be more accurately held in the appropriate temperature range.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, the air-cooling type that cools the high-voltage battery 12 with the cooling air of the cooling fan 18 is adopted. However, the cooling method is not limited to the air-cooling type, and the high-voltage battery is circulated by circulating cooling water or the like. A water-cooling type for cooling can also be adopted.

  In the above embodiment, the case where the battery cooling device is applied to a high voltage battery mounted on a hybrid vehicle has been described as an example, but the present invention can also be applied to a high voltage battery mounted on an electric vehicle or the like.

  Moreover, road information and road traffic information may be acquired by data communication from an information providing base station installed outside the vehicle, or may be acquired from another vehicle by inter-vehicle communication. Furthermore, the configuration and function sharing of each electronic control unit are not limited to the above embodiment.

It is a block diagram which shows the whole structure of the battery cooling device which concerns on embodiment. It is a figure which shows the flow of the cooling air which cools a high voltage battery. It is a flowchart which shows the process sequence of the prediction cooling control by the battery cooling device which concerns on embodiment. It is a figure which shows the relationship between battery temperature and a cooling start point. It is a figure which shows the example of a battery temperature change when predictive cooling control is performed. It is a flowchart which shows the other process sequence of the prediction cooling control by the battery cooling device which concerns on embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Battery cooling device, 10 ... BATT ECU, 12 ... High voltage battery, 14 ... Temperature sensor, 15 ... Voltage sensor, 16 ... Current sensor, 18 ... Cooling fan, 20 ... HV ECU, 22 ... Inverter, 24 ... Electric motor , 30 ... car navigation system, 32 ... NAVI ECU, 34 ... GPS receiver, 36 ... VICS receiver, 38 ... display, 40 ... EFI ECU, 42 ... engine.

Claims (5)

A battery mounted on the vehicle;
Cooling means for cooling the battery;
Travel route setting means for setting the travel route of the vehicle;
Travel route information acquisition means for acquiring travel route information related to the travel route set by the travel route setting means;
Control means for driving the cooling means when it is predicted that the temperature of the battery when traveling on the travel route is higher than a predetermined temperature based on the travel route information acquired by the travel route information acquisition means. And a battery cooling device. The travel route information acquisition means is a car navigation system that guides the vehicle to a destination,
The battery cooling device according to claim 1, wherein the travel route information is physical information of roads that constitute the travel route. The travel route information acquisition means further includes a road traffic information communication system for acquiring road traffic information from outside the vehicle,
The battery cooling apparatus according to claim 2, wherein the travel route information includes road traffic information of the road. Battery temperature acquisition means for acquiring the temperature of the battery;
Battery temperature predicting means for predicting the temperature of the battery when traveling on the travel route based on the battery temperature acquired by the battery temperature acquisition means and the travel route information;
The control unit drives the cooling unit when the battery temperature predicted by the battery temperature prediction unit is predicted to be equal to or higher than the predetermined temperature. The battery cooling device described in 1.   The battery temperature predicting means predicts a charge / discharge amount of the battery when traveling on the travel route based on the travel route information, and predicts a temperature of the battery according to the charge / discharge amount. The battery cooling device according to claim 4.

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