JP2005312276A - Condition monitor for onboard storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condition monitor for onboard storage batteries, capable of monitoring the usage condition of main machine storage batteries and an auxiliary machine storage battery with high accuracy and integrally. <P>SOLUTION: This condition monitor for the onboard storage batteries comprises a main machine detecting means that detect the usage condition of the main machine storage batteries that are mounted on a vehicle as traveling and driving sources, the auxiliary detection means that detect the usage condition of the auxiliary storage battery that drives an auxiliary electric load on the vehicle, and a data-transmitting means that transmits the detection results of the main machine detecting means and the auxiliary machine detecting means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a device for monitoring the use state of a storage battery for a driving drive source and a storage battery for an auxiliary electric load mounted on an electric vehicle or the like.

  A storage battery that can be repeatedly charged and discharged is used as a travel drive source of an electric vehicle driven by a motor or a hybrid vehicle in which a motor and an engine are used together. Nickel-metal hydride batteries and lithium batteries with high weight energy density are generally used for this storage battery, but they are vulnerable to overcharge and overdischarge, and if used under specified conditions, they will cause significant capacity reduction and abnormal heat generation. May become impossible. For this reason, for the purpose of monitoring the usage state of the storage battery, for example, a storage battery state monitoring device as disclosed in Patent Document 1 or Patent Document 2 has been developed.

  On the other hand, a vehicle is provided with a large number of auxiliary electric loads that share functions such as measurement, control, and the like, and is usually driven by a power supply voltage lower than that of a traveling drive source. Auxiliary storage batteries are used to drive these auxiliary electrical loads, and the output of the main storage battery for the travel drive source is generally transformed by a voltage converter and charged. The use state of the auxiliary battery and the operating state of the voltage converter are monitored and controlled by the vehicle integrated control device together with a large number of auxiliary electric loads.

However, in the above-described conventional method, the main engine storage battery is monitored separately by the dedicated monitoring device, and the auxiliary storage battery is monitored separately by the vehicle integrated control device. For this reason, the monitoring function is not unified, and reference information as a reference for state detection is separately held, and monitoring is performed while exchanging information between both devices, and there is a complicated software. In addition, an information transmission unit and a wire harness are necessary for exchanging information, and it is necessary to pay attention to ensuring noise resistance performance and stabilizing the power supply voltage of the apparatus, which also costs hardware. Furthermore, since both information is not synchronized, real-time monitoring and control is difficult, and there is still room for improvement in terms of accuracy.
JP 2001-333501 A JP 2002-84669 A

  The present invention has been made in view of the above background, and provides an in-vehicle storage battery state monitoring device that can monitor the use state of a main engine storage battery and an auxiliary storage battery with high accuracy and in a unified manner. Moreover, the state monitoring apparatus which can stabilize the terminal voltage at the time of charge of an auxiliary machine storage battery is provided. Furthermore, the present invention provides a state monitoring device that is not affected by noise, has a stable power supply voltage, and is excellent in economic efficiency.

  An in-vehicle storage battery state monitoring device of the present invention that solves the above-described problems includes a main unit detection means that detects a use state of a main unit storage battery for a travel drive source mounted on a vehicle, and an auxiliary device that drives an auxiliary electrical load of the vehicle. An auxiliary machine detecting means for detecting a use state of the storage battery, and a main engine detecting means and an information transmitting means for transmitting a detection result of the auxiliary machine detecting means. In addition, it is preferable to have a monitoring unit that takes in the detection results of the main unit detection unit and the auxiliary unit detection unit and monitors the usage state of the main unit storage battery and the auxiliary unit storage battery. Each of the main machine detection means and the auxiliary machine detection means preferably includes at least one of a voltage detection unit, a current detection unit, and a temperature detection unit. The monitoring unit may monitor at least one of overcharge, overdischarge, and overheat of the main unit storage battery and the auxiliary unit storage battery.

  The items for monitoring the usage state of the storage battery are generally three items: a voltage value, a current value, and a storage battery temperature, and a voltage detection unit, a current detection unit, and a temperature detection unit may be provided as detection means. However, the present invention is not limited to this, and detection means such as leakage current and ambient temperature may be provided depending on the type of storage battery. In a storage battery with a small capacity and a low terminal voltage, the three items are not essential, and may be appropriately selected in consideration of importance. In general, each detection means is driven by a power source and outputs a detection result in the form of an electrical signal.

  The number of detection means is not particularly limited. In a main storage battery configured by connecting a large number of unit cells in series, there are a method of providing one voltage detection unit at an output terminal and a method of providing a voltage detection unit for each of a plurality of cell groups. Which method is selected depends on whether charge / discharge control is performed in a batch of storage batteries or in units of cell groups, and is selected in consideration of costs. For items determined to be important, the detection means can be doubled to increase the reliability.

  The information transmission means is means for transmitting the detection results of the main machine detection means and the auxiliary machine detection means to the monitoring means or other devices. In general, the electrical signal as a detection result is subjected to signal processing such as amplification to transmit an analog electrical signal, and analog / digital conversion is performed as necessary to transmit a digital electrical signal.

  The monitoring means takes in an electrical signal from each detecting means or information transmitting means, and performs monitoring based on this. In overcharge monitoring, for example, the terminal voltage generated at the output terminal of the main engine storage battery is detected, and when it becomes higher than the allowable upper limit value, it is determined that the battery is overcharged and the charging operation is forcibly terminated. ing. Similarly, in the overdischarge monitoring, as an example, the terminal voltage generated at the output terminal of the main engine storage battery is detected, and when it becomes lower than the allowable lower limit value, it is determined that the overdischarge occurs and the vehicle is stopped. I have to. In the overheat monitoring, as an example, when the temperature of the main engine storage battery exceeds an allowable value, it is determined as overheating, and charging and discharging of the storage battery are stopped. That is, when overheating occurs, neither charging operation nor running of the vehicle is performed, and the cause of overheating is investigated.

  The monitoring method performed by the above-described monitoring means has been described by taking the main battery as an example, but the same applies to the auxiliary battery. Depending on the degree of fluctuation of the detection result, an alarm for notifying a malfunction or a command for stopping the charging operation or cutting off the load may be transmitted.

  The monitoring means may determine a control voltage for the auxiliary storage battery. In other words, the monitoring means may determine the control voltage for charging the auxiliary machine storage battery based on the information of the main battery storage battery and the terminal voltage of the auxiliary machine storage location, and perform the necessary control.

  It is preferable that the monitoring means holds reference information that serves as a reference when monitoring is performed based on the detection results of the main machine detection means and the auxiliary machine detection means. The reference information is a reference amount when the electrical signal obtained as a detection result is converted into a physical quantity or when the magnitude relation is compared, and is held in the form of a reference voltage, for example. The reference information is individually provided for each detection unit of the main unit storage battery and the auxiliary unit storage battery, but may be common if the specifications of the detection unit are the same.

  A dedicated microcomputer may be applied to the monitoring means. In this case, an input / output unit for capturing the detection result and a storage unit for recording necessary information are provided. Alternatively, the monitoring means may be provided inside the vehicle comprehensive control device and take in the detection result. In this case, a monitoring function may be added to the existing vehicle integrated control device. In either case, the monitoring of the main storage battery and the monitoring of the auxiliary storage battery, which were conventionally performed by separate devices, can be performed at the same time, and signal processing can be performed under exactly the same conditions, so high-precision and centralized monitoring is possible. It has become.

  The monitoring means preferably transmits the monitoring result to the vehicle integrated control device or the vehicle driver. As described above, the monitoring results include physical quantities such as voltage value, current value, and storage battery temperature, determination results of failure states such as overcharge, overdischarge, and overheating, alarms or instructions for stopping charging operation and vehicle running. . These monitoring results are transmitted to the vehicle integrated control device, and the vehicle integrated control device controls the auxiliary machinery electric load and the mechanism part based on the command, and stops the charging operation and the vehicle running. At the same time, the monitoring result is finally transmitted to the vehicle driver for recognition by numerical display or lamp display.

  The monitoring means obtains control information necessary for controlling the voltage converter for converting the terminal voltage of the main unit storage battery to charge the auxiliary storage battery by calculation, and transmits the control information to the voltage converter. Also good. In general, a voltage converter converts a primary input voltage with a specified transformation ratio to obtain a secondary output voltage, a control unit that specifies and controls the transformation ratio of the transformation unit, and drives the control unit And a power supply unit. Here, the primary input voltage is equivalent to the terminal voltage of the main battery, and the secondary output voltage is equivalent to the terminal voltage of the auxiliary battery. Therefore, when charging the auxiliary storage battery, it is easy for the monitoring means to determine the control voltage for obtaining the desired secondary output voltage from the acquired information of the main storage battery and the voltage value of the auxiliary storage battery. The determined control voltage is transmitted to the control unit of the voltage converter, and feedback control is performed. This method is synchronous control using voltage values of the primary and secondary at the same time, and can stabilize the secondary output voltage, that is, the terminal voltage of the auxiliary storage battery with high accuracy.

  It is preferable that the main machine detection unit, the auxiliary machine detection unit, the information transmission unit, and the monitoring unit operate with a common power source as the voltage converter. In general, a stabilized power supply is used for the power supply unit of the voltage converter. By using this in common, noise countermeasures and stabilization of the power supply voltage can be easily and economically performed.

  The in-vehicle storage battery state monitoring device of the present invention takes in the detection results of both the main machine detection means and the auxiliary machine detection means and performs signal processing under the same conditions, so that highly accurate and integrated monitoring is possible. In the configuration in which the control voltage for obtaining the desired secondary output voltage is transmitted to the voltage converter that charges the auxiliary storage battery, the terminal voltage of the auxiliary storage battery during charging can be stabilized with high accuracy. Further, in a configuration that operates with a power supply common to the voltage converter, noise countermeasures and power supply voltage stabilization can be easily and economically performed.

  The best mode for carrying out the present invention will be described with reference to the functional block diagram of FIG. In the figure, broken arrows indicate the flow of signals, information, and control, and switches and connection connectors are omitted for simplicity. The in-vehicle storage battery state monitoring device 1 of the present invention includes a main unit detection unit 11 that detects a use state of a main unit storage battery 61, an auxiliary unit detection unit 21 that detects a use state of an auxiliary unit storage battery 62, an information transmission unit 31, It is comprised with the monitoring determination part 41 corresponded to the monitoring means.

  The main engine storage battery 61 mounted on the vehicle is configured by connecting a large number of unit cells such as nickel metal hydride batteries and lithium batteries in series, a motor 64 is connected to the output terminal via an inverter circuit 63, and a charge switch 66. A charging terminal 65 is attached via the. The main engine storage battery 61 is charged from the charging terminal 65 to a terminal voltage of about 300 V by an external power source, and supplies the charged energy to the motor 64 to drive the vehicle. A voltage detector 12, a current detector 13, and a temperature detector 14 are provided as main engine detectors 11 for detecting the usage state of the main battery 61, and detect the terminal voltage, output current, and storage battery temperature, respectively.

  A large number of auxiliary electric loads 67 are connected to the output terminal of the auxiliary battery 62, and are charged to a terminal voltage of about 14V in order to drive them. As an auxiliary machine detection means 21 for detecting the usage state of the auxiliary battery 62, a voltage detection unit 22, a current detection unit 23, and a temperature detection unit 24 are provided to detect a terminal voltage, an output current, and a storage battery temperature, respectively. Yes.

  As an example of these detection means, the voltage detectors 12 and 22 are electrostatic voltage dividing type voltage sensors, the current detectors 13 and 23 are DC current sensors utilizing the Hall effect, and the temperature detectors 14 and 24 are A resistance temperature detector, a thermocouple, or the like is used, each driven by a power source, and an electric signal is output as a detection result.

  The information transmission means 31 includes an electric signal from the voltage detection unit 12, the current detection unit 13, and the temperature detection unit 14 on the main unit storage battery 61 side, a voltage detection unit 22, a current detection unit 23 on the auxiliary machine storage battery 62 side, and a temperature. The electric signal of the detection unit 24 is captured, signal processing is performed, and the signal is transmitted to the monitoring determination unit 41.

  The monitoring determination unit 41 takes in the electrical signal of the detection result of each detection unit from the information transmission unit 31, and based on the stored reference information, each electrical signal has a physically meaningful voltage value and current value. Then, it is converted into a measured value of the storage battery temperature to grasp the usage state. Further, it is compared with a trip value or alarm value set in advance to determine whether the use state is normal or a malfunction has occurred, and an alarm or command is transmitted when a malfunction occurs. Reference information is required for each detection means, but may be common if the specifications of the detection means are the same. For example, if the measured temperature ranges and output specifications of the temperature detectors 14 and 24 of the storage batteries 61 and 62 are the same, only one piece of common reference information is sufficient.

  Monitoring by the monitoring determination unit 41 is performed as follows. When the main storage battery 61 is being charged from the charging terminal 65, the voltage value of the output terminal gradually increases as the amount of charge increases, and the voltage value gradually decreases when the main battery 61 is discharged due to vehicle travel. . Maintaining this voltage value within an appropriate range and not overcharging or overdischarging is important in securing the performance and life of the vehicle. Therefore, the trip upper limit value is set to a level lower than the upper limit of the appropriate range, and when the voltage value exceeds the trip upper limit value, it is determined that the battery is overcharged, and the charging switch 66 is opened to forcibly terminate the charging operation. I am trying to issue a command to do. Further, an alarm upper limit value is set at a level lower than the trip upper limit value, and an alarm for notifying overcharge is transmitted in advance when the voltage value exceeds the alarm upper limit value.

  The same applies to overdischarge while the vehicle is running. When the voltage value falls below the trip lower limit set to a level higher than the lower limit of the appropriate range, it is determined that the vehicle is overdischarged and a command is issued to stop the vehicle running. I am doing so. In addition, when the voltage value falls below the alarm lower limit value set to a level higher than the trip lower limit value, an alarm for notifying overdischarge is transmitted in advance.

  When the detected voltage value is between the alarm upper limit value and the alarm lower limit value, it is determined as a normal use state, and the charge amount is grasped from the voltage value.

  The monitoring of the voltage value of the auxiliary storage battery 62 is also the same. The charging operation is forcibly terminated at the trip upper limit value, and the auxiliary electric load 67 is shut off at the trip lower limit value. Note that it may be possible to safely stop the vehicle by running the vehicle for only a short time without interrupting only the minimum electric load necessary for running.

  There is no lower limit for monitoring the current value, and usually only the trip value on the upper limit side is set. When charging or discharging the storage battery, heat is generated to some extent inside the storage battery, but if the current value is too large, the battery is overheated. Therefore, the trip value is set to a level lower than the maximum allowable current, and when the detected current value exceeds the trip value, it is judged as an overcurrent state, forcibly stopping the charging operation or partially reducing the load. Is to be commanded. The partial reduction of the load is a limitation of the traveling speed in the main battery 61, and the selective interruption of the auxiliary electric load 67 corresponds to the auxiliary battery 62.

  The monitoring of the storage battery temperature is also the upper limit monitoring similar to the current value. When a trip value lower than the maximum allowable temperature specified in the storage battery specifications is set and the detected storage battery temperature exceeds the trip value, it is determined that the battery is overheated and the charging operation is forcibly stopped or part of the load. Command to mitigate. Note that a plurality of trip values may be set, and monitoring and control may be performed so as to limit the load stepwise depending on the degree of increase in the storage battery temperature.

  In addition to the above, even when a monitoring item is determined and a detection unit is provided, the monitoring determination unit 41 may appropriately capture a detection result and perform necessary signal processing. As the monitoring determination unit 41, a microcomputer having an input / output unit and a storage unit can be applied.

  In addition, the monitoring determination unit 41 transmits the monitoring result to the vehicle integrated control device 71 by data communication. Thereby, measured values such as a voltage value, a current value, a storage battery temperature, a determination result of the use state of the storage battery, an alarm and a command are transmitted to the vehicle integrated control device 71, and are displayed and transmitted to the vehicle driver. . Further, based on the command, the vehicle comprehensive control device 71 performs control such as termination of the charging operation, stop of the vehicle travel, and interruption of the auxiliary electric load 67. The vehicle integrated control device 71 monitors and controls a large number of items in the vehicle including the auxiliary electric load 67. However, the storage battery 61, 62 can be directly displayed to the vehicle driver without going through this. The monitoring result may be transmitted.

  The voltage converter 81 converts the electrical energy stored in the main battery 61 into a different voltage form and charges the auxiliary battery 62. The voltage converter 81 is connected to the terminals of both the batteries 61 and 62, and The control unit 83 controls the transformation unit 82 and the power supply unit 84 that drives the control unit 83. As a typical example of DC voltage conversion, a pulse width control method will be described. Inside the transformer 82, the DC voltage of the main engine storage battery 61 is converted into a positive and negative rectangular wave pulse, transformed by a pulse transformer, rectified and smoothed, and the auxiliary machine A low DC voltage of the storage battery is generated, and the control unit 83 can change the transformation ratio by controlling the width of the rectangular wave pulse. Although the terminal voltage of both the storage batteries 61 and 62 changes every moment by charging / discharging, in order to keep the terminal voltage of the auxiliary machine storage battery 62 optimal, the state monitoring apparatus 1 can be applied.

  That is, the monitoring determination unit 41 can easily determine the desired control voltage of the auxiliary storage battery 62 based on the measured values of the terminal voltages of the storage batteries 61 and 62, and the value of the control voltage can be converted into a voltage converter. It may be transmitted to the control unit 83 of 81. Thereby, the control unit 83 can optimally control the width of the rectangular wave pulse of the transformer 82. This is real-time feedback control based on synchronized information, and extremely accurate management can be performed. The control voltage transmission method may be general-purpose communication or analog signal transmission.

  The power supply unit 84 of the voltage converter 81 uses a stabilized power supply that is less affected by ambient temperature and noise and has a constant output voltage, so that the control unit 83 can control the transformation unit 82 with high accuracy. ing. This stable power supply unit 84 is connected to the information transmission means 31 and used in common in the state monitoring device 1. By driving the detection means 12-14, 22-24, the weak electric signal that is output can be stabilized.

  FIG. 2 is a functional block diagram showing another example of the present invention, and the monitoring determination unit 41 is arranged inside the vehicle integrated control device 71. The electrical signals from the detection units 12 to 14 and 22 to 24 are taken into the monitoring determination unit 41 by the information transmission unit 31. The monitoring determination unit 41 operates in the same manner as in the form of FIG. 1, but the monitoring result is directly used inside the vehicle integrated control device 71.

  FIG. 3 is a functional block diagram showing still another example, in which the power supply unit 32 of the information transmission means 31 in the form of FIG. 2 is omitted and the power supply unit 84 of the voltage converter 81 is used in common. As a result, the electrical signals of the detection means 12-14 and 22-24 can be stabilized as described above.

  The above is the form of the present invention, and the effect will be described next. In the conventional configuration shown in FIG. 4, functions are shared and monitored by the monitoring unit 91 of the main storage battery 61 and the vehicle integrated control device 71 that monitors the auxiliary storage battery 62. Accordingly, there is a difference between the processing functions of the two, reference information is also held separately, and environmental conditions such as electrical noise conditions, power supply voltage fluctuations, and ambient temperature are also different. Moreover, when comparing the detection results of both, information must be exchanged by communication or the like, and synchronization has not been achieved. On the other hand, the monitoring determination unit 41 of the present invention performs monitoring determination by taking in both the detection result of the main machine detection means 11 and the detection result of the auxiliary machine detection means 21. Therefore, signal processing can be performed in synchronization under exactly the same conditions, and centralized monitoring is possible.

  Further, while the vehicle integrated control device 71 determines the installation location due to restrictions on the member arrangement of the entire vehicle, the monitoring determination unit 41 can be installed in the vicinity of the storage batteries 61 and 62. Therefore, the wiring harness can be routed easily and easily, and the weak electric signals of the detection means 12 to 14 and 22 to 24 are not affected by noise. Furthermore, the ambient temperature of the main engine storage battery 61 is sufficiently managed to maintain the performance, and the performance can be further stabilized if the monitoring / determination unit 41 is installed in the same place. As these comprehensive effects, highly accurate monitoring can be realized economically.

  In the configuration in which the control voltage of the auxiliary battery 62 is transmitted to the voltage converter 81, real-time feedback control based on synchronized information can be performed, so that the terminal voltage during charging of the auxiliary battery 62 can be stabilized with high accuracy. In addition, the state monitoring device 1 that commonly uses the power supply unit 84 of the voltage converter 81 has a stable power supply voltage in each unit, so that detection accuracy is improved and operation is stabilized.

  The on-board storage battery state monitoring device of the present invention can be widely applied to electric vehicles and hybrid vehicles regardless of the type of storage battery and charging / discharging method.

It is a functional block diagram which shows the state monitoring apparatus of the vehicle-mounted storage battery of this invention. It is a functional block diagram which shows another example of this invention. It is a functional block diagram which shows another example of this invention. It is a functional block diagram which shows the state monitoring apparatus of the conventional vehicle-mounted storage battery.

Explanation of symbols

1: Status monitoring device 11: Main machine detection means 21: Auxiliary machine detection means 12, 22: Voltage detection unit 13, 23: Current detection unit 14, 24: Temperature detection unit 31: Information transmission unit 32: Power supply unit of information transmission unit 41: Monitoring determination unit 61: Main machine storage battery 62: Auxiliary storage battery 63: Inverter circuit 64: Motor 65: Charging terminal 66: Charging switch 67: Auxiliary electric load 71: Vehicle integrated control device 81: Voltage converter 82: Transformer Unit 83: Control unit: 84: Power supply unit 91: Conventional monitoring unit for main storage battery 92: Conventional monitoring unit for auxiliary storage battery

Claims (11)

Main engine detection means for detecting a use state of a main engine storage battery for a traveling drive source mounted on a vehicle;
Auxiliary equipment detection means for detecting the usage state of an auxiliary battery that drives the electric load of the auxiliary equipment of the vehicle;
Information transmission means for transmitting detection results of the main machine detection means and the auxiliary machine detection means;
A state monitoring device for an in-vehicle storage battery, comprising:   The in-vehicle storage battery state monitoring device according to claim 1, further comprising a monitoring unit that captures detection results of the main unit detection unit and the auxiliary unit detection unit and monitors usage states of the main unit storage battery and the auxiliary unit storage battery.   The in-vehicle storage battery state monitoring device according to claim 1 or 2, wherein each of the main engine detection means and the auxiliary machine detection means includes at least one of a voltage detection unit, a current detection unit, and a temperature detection unit.   The in-vehicle storage battery state monitoring device according to claim 2 and 3, wherein the monitoring means monitors at least one of overcharge, overdischarge, and overheat of the main storage battery and the auxiliary storage battery.   The in-vehicle storage battery state monitoring device according to claim 2 and 3, wherein the monitoring means determines a control voltage of the auxiliary storage battery.   The in-vehicle storage battery state monitoring device according to claim 2, wherein the monitoring unit holds reference information serving as a reference when monitoring is performed based on detection results of the main engine detection unit and the auxiliary machine detection unit. .   The on-board storage battery status monitoring device according to claim 2, wherein the monitoring means is a dedicated microcomputer.   The in-vehicle storage battery state monitoring device according to claim 2, wherein the monitoring unit is disposed inside the vehicle integrated control device.   The in-vehicle storage battery state monitoring device according to claim 2, wherein the monitoring unit transmits a monitoring result to a vehicle integrated control device or a vehicle driver.   The monitoring means obtains control information necessary for controlling a voltage converter for converting the terminal voltage of the main battery and charges the auxiliary battery by calculation, and transmits the control information to the voltage converter. The in-vehicle storage battery state monitoring device according to 2-9.   The in-vehicle storage battery status monitoring device according to claim 10, wherein the main engine detection means, the auxiliary machine detection means, the information transmission means, and the monitoring means operate with a power source common to the voltage converter.

Images