JP2011033632A - Stator of rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery charge and discharge current detection apparatus that improves the detection accuracy of a charge and discharge current of a battery, and that certainly finds a failure of a current detection resistor. <P>SOLUTION: The battery charge and discharge current detection apparatus 100 detects a charge and discharge current of a battery 200 mounted on a vehicle using a shunt resistor 210 connected to a negative terminal of the battery 200, and includes a voltage amplifier 130 for detecting shunt voltage, an A/D 132, a current value calculation unit 150 for detecting the charge and discharge current of the battery 200 based on the detected shunt voltage, a shunt failure detection part 144 for detecting the presence of a failure of the shunt resistor 210, an alarm device 160 for notifying the outside when a failure is detected, and a communication processing part 170. The negative terminal of the battery charge and discharge current detection apparatus 100 for power supply connection is connected to the negative terminal of the battery 200. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a battery charge / discharge current detection device that detects a charge / discharge current of a battery mounted on a passenger car, a truck, or the like.

2. Description of the Related Art Conventionally, a battery remaining amount display device that detects a charge / discharge current of a battery based on a voltage across a current detection resistor inserted between a negative electrode side terminal of the battery and a ground is known (for example, a patent) Reference 1). In this battery remaining amount display device, the remaining amount of the battery is calculated and displayed by integrating the detected charge / discharge currents.
JP-A-6-176798 (page 4-5, Fig. 1-3)

  By the way, in recent years, computerization has progressed in order to improve the convenience of vehicles, and large current electric loads used during operation of power steering, brakes, and the like are increasing. For this reason, a large current may flow during the operation of the vehicle, and the following problems occur when the charge / discharge current of the battery is detected using the current detection resistor.

  When the vehicle body is used as a ground as with other in-vehicle devices, the voltage drop changes according to the current flowing through the current detection resistor. It becomes stable and the current detection accuracy decreases. Further, if the temperature rises when a current flows through the current detection resistor, a temperature drift of the resistance value occurs, so that the current detection accuracy further decreases.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a battery charge / discharge current detection device with improved detection accuracy of the battery charge / discharge current.

  In order to solve the above-described problem, a battery charge / discharge current detection device of the present invention detects a charge / discharge current of a battery mounted on a vehicle using a current detection resistor connected to a negative electrode side terminal of the battery. A charge / discharge current detecting device for detecting a voltage at both ends of a current detection resistor, and a current value detection for detecting a charge / discharge current of the battery based on a voltage at both ends of the current detection resistor detected by the voltage detection means. And an abnormality detection means for detecting the presence or absence of an abnormality in the current detection resistor, and a negative terminal for power connection is connected to the negative terminal of the battery.

  Since the negative terminal for power connection of the battery charge / discharge current detection device is connected to the negative terminal of the battery, not to the ground where one end of the current detection resistor (the opposite side of the battery) is connected, Even when a large current flows during cranking etc., the influence of the voltage drop due to the current detection resistor can be eliminated, and the current detection accuracy can be improved by stabilizing the operation of the battery charge / discharge current detection device. It becomes.

  Furthermore, it further includes connection switching means for connecting the bypass means in parallel with the current detection resistor when an abnormality is detected by the above-described abnormality detection means. Even if the resistance value of the current detection resistor becomes abnormally high or fusing, etc., it is possible to prevent the battery charge / discharge current detection device from completely floating from the ground. Communication can be performed reliably regardless of whether or not there is.

  The connection switching means described above is connected between the current detection resistor and the voltage detection means, and the bypass means is composed of two switches, and one switch is connected between the input terminals of the voltage detection means, It is desirable that the other switch be connected between the one of the switches that is not connected to the negative electrode terminal of the battery in the current detection resistor.

  Moreover, it is desirable to use the connection switching means as a bypass means for the current detection resistor by turning on the two switches as the bypass means described above.

  Further, it further includes a zero point correction unit that performs zero point correction of the current detection detection unit by realizing a state in which the voltage across the current detection resistor is virtually zero by switching the connection by the connection switching unit described above. It is desirable. By connecting the bypass means in parallel with the current detection resistor, the voltage across the current detection resistor can be virtually reduced to zero, so a state where no current flows through the current detection resistor can be created. Current detection accuracy can be improved by performing zero point correction using the detected voltage (or current) value.

  Further, it is preferable that the abnormality detection unit described above detects the presence or absence of abnormality based on the voltage across the current detection resistor detected by the voltage detection unit. When the voltage across the normal range is detected, the abnormality of the current detection resistor can be reliably detected. Moreover, since the voltage across the current detection resistor is detected for detecting the charge / discharge current of the battery, it is possible to detect an abnormality in the current detection resistor without adding a special configuration.

  Further, it is preferable that the apparatus further includes temperature detecting means for detecting the temperature of the current detection resistor described above, and the abnormality detecting means detects presence / absence of an abnormality based on the temperature detected by the temperature detecting means. Accordingly, it is possible to detect an abnormality such as when the resistance value is abnormally high and the heat generation amount exceeds the allowable range. In addition, if the temperature of the current detection resistor is known, temperature compensation can be performed based on the relationship between the resistance value of the current detection resistor measured in advance and the temperature, and current detection accuracy can be easily increased. it can.

  In addition, it is desirable to further include notification means for notifying the abnormality detected by the abnormality detection means described above. As a result, it is possible to detect the abnormality of the current detection resistor and perform notification so as to reduce the load current in advance and take measures such as repair or replacement so as not to further deteriorate the state.

  Moreover, it is desirable that the above-mentioned notification means notifies the abnormality to the external control device by wireless communication means not via a communication line. When the resistance value of the current detection resistor becomes abnormally high or fusing occurs, if the battery charge / discharge current detection device is completely lifted from the ground, a signal is sent via the communication line with the ground as the potential reference. However, wireless communication using radio waves or infrared rays that do not pass through the communication line eliminates such inconvenience, and thus communication can be performed reliably regardless of whether the current detection resistor is abnormal.

  The notification means described above is preferably an alarm device that visually or audibly notifies an abnormality. As a result, the abnormality or the like can be directly notified to the driver or the like without using another device (such as an external control device).

  In order to solve the above-described problem, the battery charge / discharge current detection device of the present invention detects a charge / discharge current of a battery mounted on a vehicle using a current detection resistor connected to a negative terminal of the battery. A battery charge / discharge current detection device for detecting a charge / discharge current of a battery based on a voltage detection means for detecting a voltage across the current detection resistor and a voltage across the current detection resistor detected by the voltage detection means. A value detecting means and an abnormality detecting means for detecting the presence or absence of an abnormality in the current detection resistor, and connecting the negative electrode side terminal for power connection to the negative electrode side terminal of the battery and connecting them in parallel with the current detection resistor. It further includes first and second diodes having opposite polarities. As a result, when an abnormality occurs in the current detection resistor and the voltage across the terminal becomes higher than the forward voltage drop of the diode, a current flows between the battery and the ground via the first and second diodes. be able to. Therefore, it is possible to prevent the battery charge / discharge current detection device from completely floating from the ground, and it is possible to reliably perform communication regardless of whether the current detection resistance is abnormal. Further, by using the first and second diodes capable of flowing the charging / discharging current of the battery, the charging / discharging operation of the battery can be continued even when an abnormality occurs in the current detection resistor.

It is a figure which shows the functional block of the battery charging / discharging electric current detection apparatus of one Embodiment. It is a figure which shows the specific structure of the battery charging / discharging electric current detection apparatus shown in FIG. It is a flowchart which shows the main operation | movement flow which performs electric current detection in a battery charging / discharging electric current detection apparatus. It is a flowchart which shows the specific example of abnormality determination of shunt resistance performed in step 100 of FIG. It is a flowchart which shows the specific example of the process at the time of the shunt abnormality performed in step 101 of FIG. It is a flowchart which shows the specific example of the 0 point correction process performed in step 103 of FIG. It is a figure which shows the modification which prevents that a ground floats when abnormality arises in shunt resistance. 6 is a flowchart in the case where connection switching is performed by a ground switching unit as necessary in a process when a shunt abnormality is performed when an abnormality occurs in a shunt resistor.

  Hereinafter, a battery charge / discharge current detection device according to an embodiment to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a diagram illustrating functional blocks of a battery charge / discharge current detection device according to an embodiment. The battery charge / discharge current detecting device 100 shown in FIG. 1 has a voltage (a voltage appearing at both ends of a shunt resistor 210 as a current detecting resistor inserted between a negative terminal of an in-vehicle battery 200 and a ground (for example, a vehicle body). The operation of detecting the charging / discharging current of the battery 200 based on the shunt voltage is performed.

  The battery charge / discharge current detection device 100 includes a power supply circuit 110, a GND (ground) switching unit 120, a voltage amplification unit 130, analog-digital converters (A / D) 132 and 142, a temperature detection unit 140, and a shunt abnormality detection unit. 144, a current value calculation unit 150, a zero point correction unit 152, a storage unit 154, an alarm device 160, and a communication processing unit 170.

  The power supply circuit 110 generates an operating voltage to be supplied to each part of the battery charge / discharge current detection device 100. The power supply circuit 110 has two terminals for connecting power (a negative terminal and a positive terminal). The negative terminal for power connection is the negative terminal of the battery 200 and the positive terminal for power connection. Are connected to the positive terminal of the battery 200, respectively.

  The ground switching unit 120 is connected between the shunt resistor 210 and the voltage amplification unit 130 and in parallel with the shunt resistor 210. The ground switching unit 120 includes two switches SW1 and SW2. When the voltage appearing at both ends of the shunt resistor 210 is applied to the voltage amplifier 130, only the switch SW2 is turned on and the switch SW1 is turned off. At the time of zero point correction, only the switch SW1 is turned on and the switch SW2 is turned off. Further, by turning on both the switches SW1 and SW2, the ground switching unit 120 can be used as a bypass means for the shunt resistor 210, and the energization path can be bypassed via the shunt resistor 210.

  The voltage amplifier 130 amplifies the shunt voltage appearing at both ends of the shunt resistor 210. The amplified shunt voltage is converted into digital data (shunt voltage data) by the analog-digital converter 132. The temperature detector 140 detects the temperature of the shunt resistor 210. The voltage corresponding to the detected temperature is converted into digital data (shunt temperature data) by the analog-digital converter 142.

  The shunt abnormality detection unit 144 detects whether or not the shunt resistor 210 is abnormal based on the shunt voltage data and the shunt temperature data. The current value calculation unit 150 calculates the charge / discharge current of the battery 200 (current flowing through the shunt resistor 210) based on the shunt voltage data. In addition, the current value calculation unit 150 performs temperature compensation based on the shunt temperature data, and performs a process of correcting a change in the resistance value of the shunt resistor 210 due to temperature.

  The zero point correction unit 152 performs a zero point correction process after switching the connection state of the two switches SW1 and SW2 in the ground switching unit 120. The result is stored in the storage unit 154 and held.

  When the abnormality of the shunt resistor 210 is detected by the shunt abnormality detection unit 144, the alarm device 160 notifies the outside to that effect. When the abnormality of the shunt resistor 210 is detected by the shunt abnormality detection unit 144, the communication processing unit 170 transmits that fact to the ECU 300 as an external control device by communication.

  FIG. 2 is a diagram illustrating a specific configuration of the battery charge / discharge current detection device 100 illustrated in FIG. 1. For example, a configuration realized using a microcomputer is illustrated. The internal configuration of the battery charge / discharge current detection device 100 shown in FIG. 2 is as follows when it corresponds to the functional block shown in FIG.

  (1) The switch SW1 in the ground switching unit 120 is configured by a MOS-FET (MOS1), and the switch SW2 is configured by a MOS-FET (MOS2). A signal for turning on and off the MOS1 and MOS2 is input from the microcomputer 180.

  (2) The temperature detection unit 140 includes a voltage dividing circuit including a resistor 143 and a thermal element 141. The thermal element 141 is an element whose resistance value changes depending on temperature, and is attached to the shunt resistor 210 directly or via a predetermined substrate and thermally coupled thereto. In the example shown in FIG. 2, when the temperature of the shunt resistor 210 increases, the temperature of the thermal element 141 also increases, and accordingly, the resistance value of the thermal element 141 increases, and the shunt temperature output from the analog-digital converter 142 is increased. The value of data increases.

  (3) The alarm device 160 includes an LED 162 and a speaker 164. An LED 162 is used to visually notify the abnormality. For example, the LED is turned on when an abnormality occurs. A speaker 164 is used to audibly notify the abnormality. For example, a predetermined warning sound is output from the speaker 164 when an abnormality occurs.

  (4) The communication processing unit 170 includes a communication controller 172 and a driver 174. The communication controller 172 performs a modulation process by converting a shunt abnormality signal output from the microcomputer 180 when the abnormality occurs in the shunt resistor 210 into a predetermined format for digital communication (for example, LIN). The modulated signal (digital modulation signal) is transmitted from the driver 174 to the ECU 300 via the communication line.

  (5) The microcomputer 180 includes a CPU 182, a ROM 184, a RAM 186, and an input / output processing unit (I / O) 188, and the CPU 182 executes a predetermined operation program stored in the ROM 184. The operations of the shunt abnormality detection unit 144, the current value calculation unit 150, and the zero point correction unit 152 illustrated in FIG. 1 are performed. A RAM 186 is used as the storage unit 154. In the present embodiment, each operation of the shunt abnormality detection unit 144, the current value calculation unit 150, and the zero point correction unit 152 is performed using the microcomputer 180, but the same operation is performed by a dedicated logic circuit. Also good.

  The voltage amplifying unit 130 needs to amplify positive and negative shunt voltages (charge / discharge currents of the battery 200). Therefore, the voltage amplifying unit 130 needs to be configured for this purpose. Since it is applicable as it is, details are omitted. Specifically, an amplifier that amplifies the positive shunt voltage and an amplifier that amplifies the negative shunt voltage are provided separately, and the output of one of the amplifiers is used depending on the polarity of the shunt voltage. A method of amplifying the shunt voltage after applying a predetermined bias voltage with an amplifier so as to obtain a shunt voltage (or negative shunt voltage) is conceivable.

  The voltage amplification unit 130 and the analog-digital converter 132 described above are used as voltage detection means, the current value calculation unit 150 is used as current value detection means, the shunt abnormality detection unit 144 is used as abnormality detection means, an alarm device 160, and a communication processing unit 170. The temperature detection unit 140 and the analog-digital converter 142 correspond to the temperature detection unit, the ground switching unit 120 corresponds to the connection switching unit and the bypass unit, and the zero point correction unit 152 corresponds to the zero point correction unit.

  The battery charge / discharge current detection device 100 of this embodiment has such a configuration, and the operation thereof will be described next. FIG. 3 is a flowchart showing a main operation flow for performing current detection in the battery charge / discharge current detection device 100. This main operation flow is performed at regular time intervals (for example, every 4 msec). Alternatively, a part or the whole may be executed irregularly by an interrupt operation or the like.

  First, the shunt abnormality detection unit 144 determines whether or not there is an abnormality in the shunt resistor 210 (step 100). If there is an abnormality, an affirmative determination is made, and the shunt abnormality detection unit 144 sends an instruction to the ground switching unit 120 to perform processing at the time of the shunt abnormality (step 101).

  On the other hand, if there is no abnormality in the shunt resistor 210, a negative determination is made in the determination in step 100, and then the zero point correction unit 152 determines whether it is the timing for the zero point correction (step 102). For example, if zero point correction is performed at intervals of 3 seconds and the interval is measured by a timer, the step is performed by checking whether a time-up signal is output from the timer after 3 seconds have elapsed since the timer was started. 102 determinations can be made. When the timing for zero point correction has arrived, an affirmative determination is made in the determination in step 102, and then the zero point correction unit 152 performs zero point correction processing (step 103) and resets the timer (step 104). .

  After the timer is reset, or when the timing for the zero point correction has not arrived, a negative determination is made in the determination in step 102, and then the current value calculation unit 150 stores the zero point correction stored in the storage unit 154. The processing data is read (step 105), and the charge / discharge current (battery current) of the battery 200 flowing through the shunt resistor 210 is calculated based on the shunt voltage (step 106). The value of the battery current obtained by the calculation is sent from the communication processing unit 170 to the ECU 300 (step 107). In this way, a series of battery current detection operations are completed.

  FIG. 4 is a flowchart showing a specific example of the determination of abnormality of the shunt resistance performed in step 100 of FIG. First, the shunt abnormality detection unit 144 reads the shunt temperature data output from the analog-digital converter 142 (step 200), and based on the read shunt temperature data, the temperature of the shunt resistor 210 is the upper limit value of the allowable value. It is determined whether or not a certain Tmax is exceeded (step 201). If it exceeds, an affirmative determination is made and it is determined that the shunt is abnormal (step 202).

  Further, the shunt abnormality detection unit 144 reads the shunt voltage data output from the analog-digital converter 132 (step 203), and the shunt voltage exceeds the allowable upper limit value Vmax based on the read shunt voltage data. It is determined whether or not it is lower than the lower limit value Vmin (steps 204 and 205). If any of these is true, an affirmative determination is made at each step, and it is determined that the shunt is abnormal (step 206).

  FIG. 5 is a flowchart showing a specific example of the shunt abnormality process performed in step 101 of FIG. First, the shunt abnormality detection unit 144 sends an instruction to the ground switching unit 120 to switch the ground connection state (step 300). Specifically, the switch SW1 is turned off and the switch SW2 is turned on when the battery current is detected, and both the switches SW1 and SW2 are turned on. Thereafter, the LED 162 is turned on and an alarm sound is output from the speaker 164 using the alarm device 160 (step 301), and a shunt abnormality signal is transmitted to the ECU 300 using the communication processing unit 170 (step 302).

  FIG. 6 is a flowchart showing a specific example of the zero point correction process performed in step 103 of FIG. First, the zero point correction unit 152 sends an instruction to the ground switching unit 120 to turn off the switch SW2 and turn on the switch SW1 (steps 400 and 401). Thereby, the input terminals of the voltage amplifying unit 130 are short-circuited via the switch SW1, so that a state where the current flowing through the shunt resistor 210 is 0A and the shunt voltage is 0V is virtually generated.

  The zero point correction unit 152 records the shunt voltage obtained corresponding to such a connection state as the zero point in the storage unit 154 (step 402). Thereafter, the zero point correction unit 152 sends an instruction to the ground switching unit 120 to switch off the switch SW1 and switch on the switch SW2 (steps 403 and 404). The current value calculation unit 150 obtains the shunt voltage after the zero point correction by subtracting the zero point value stored in the storage unit 154 in this way from the actually obtained shunt voltage value. An accurate shunt current can be calculated.

  Thus, in the battery charge / discharge current detection device 100 of the present embodiment, the negative terminal for power connection is not the ground to which one end of the shunt resistor 210 (the side opposite to the battery 200) is connected, but the battery 200 Since it is connected to the negative terminal, the influence of the voltage drop due to the shunt resistor 210 can be eliminated even when a large current flows when cranking the engine or using a large current electric load such as power steering. The current detection accuracy can be improved by stabilizing the operation of the battery charge / discharge current detection device 100. Further, by detecting and notifying the abnormality of the shunt resistor 210, it becomes possible to reduce the load current in advance and take measures such as repair or replacement so as not to further deteriorate the state.

  Further, the shunt abnormality detection unit 144 detects the presence or absence of an abnormality based on the shunt voltage, and can reliably detect an abnormality in the shunt resistor 210 when a shunt voltage outside the normal range is detected. In addition, since the shunt voltage is detected for detecting the charging / discharging current of the battery 200, the abnormality of the shunt resistor 210 can be detected without adding a special configuration.

  Further, the shunt abnormality detection unit 144 detects the presence or absence of abnormality based on the shunt temperature detected using the temperature detection unit 140, and the resistance value of the shunt resistor 210 becomes abnormally high, so that the heat generation amount is within an allowable range. It is possible to detect abnormalities such as exceeding. If the temperature of the shunt resistor 210 is known, temperature compensation can be performed based on the relationship between the resistance value of the shunt resistor 210 measured in advance and the temperature, and the current detection accuracy can be easily increased. it can. In particular, the abnormality of the shunt resistor 210 can be reliably detected by detecting the shunt temperature using the thermal element 141 thermally coupled to the current detection resistor. Further, when the shunt resistor 210 is thermally coupled to the negative terminal of the battery 200, the battery temperature can be detected. Therefore, the abnormality of the battery 200 can be detected by detecting the abnormality of the shunt resistor 210. Can also be detected.

  The notification means described above is preferably an alarm device that visually or audibly notifies an abnormality. As a result, the abnormality or the like can be directly notified to the driver or the like without using another device (such as an external control device).

  In addition, when an abnormality is detected in the shunt resistor 210, the ground switching unit 120 that connects the bypass means in parallel with the shunt resistor 210 is used, so that the resistance value of the shunt resistor 210 becomes abnormally high, fusing, etc. Even when the battery charging / discharging current detection device 100 occurs, it is possible to prevent the battery charge / discharge current detection device 100 from completely floating from the ground. ECU 300 can be notified by communication.

  Further, by connecting a bypass means by the ground switching unit 120 in parallel with the shunt resistor 210, the voltage across the shunt resistor 210 can be virtually reduced to 0, so that no current flows through the shunt resistor 210. The current detection accuracy can be increased by performing zero-point correction using the voltage (or current) detection value at this time.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the above-described embodiment, the connection state by the ground switching unit 120 is switched when an abnormality occurs in the shunt resistor 210 (step 300 in FIG. 5), but the ground is prevented from floating by another method. May be.

  FIG. 7 is a diagram illustrating a modification in which the ground is prevented from floating when an abnormality occurs in the shunt resistor 210. The ground (GND) automatic switching unit 190 shown in FIG. 7 includes first and second diodes 192 and 194 that are connected in parallel with the shunt resistor 210 and have opposite polarities. Even if an abnormality occurs in the shunt resistor 210 and the voltage at both ends thereof becomes higher than the forward voltage drop of the first diode 192 (including the case where the shunt resistor 210 is opened due to melting, etc.), the first diode 192 Current can flow between the battery 200 and the ground. Therefore, it is possible to prevent the battery charge / discharge current detection device 100 from completely floating from the ground, and reliably communicate regardless of whether or not the shunt resistor 210 is abnormal (even if an abnormality occurs). Can be done. Further, by using the first and second diodes 192 and 194 as power elements capable of flowing the charging / discharging current of the battery 200, charging and discharging of the battery 200 is possible even when an abnormality occurs in the shunt resistor 210. The discharge operation can be continued. The configuration shown in FIG. 7 may be used together with the ground switching unit 120 shown in FIG. 1 or may be replaced with the ground switching unit 120.

  In the above-described embodiment, the connection of the ground switching unit 120 is always switched (step 300 in FIG. 5) as the shunt abnormality processing (step 101 in FIG. 3). However, the connection switching is performed only when necessary. It may be.

  FIG. 8 is a flow chart in the case where the connection switching by the ground switching unit 120 is performed as necessary in the processing at the time of the shunt abnormality performed when the abnormality occurs in the shunt resistor 210. Note that the flowchart shown in FIG. 8 shows an operation procedure that focuses only on ground switching, and a notification that is made when an abnormality occurs is omitted.

  When an abnormality occurs (affirmative determination at step 500), the shunt abnormality detection unit 144 determines whether or not ground switching is necessary (step 501). For example, when it is determined that the shunt resistor 210 is abnormal based on the shunt temperature, but the resistance value or shunt voltage of the shunt resistor 210 is in a normal range, or when the shunt resistor 210 is short-circuited, the shunt voltage is in the normal range. In the case where the voltage is lower than the threshold value, the shunt resistor 210 is abnormal but the ground switching is not necessary. On the other hand, when the shunt voltage becomes higher than the normal range or when the shunt voltage fluctuates rapidly and is not stable, it is necessary to switch the ground, and an affirmative determination is made in the determination of step 501, and the ground switching is performed. (Step 502).

  In the above-described embodiment, the communication between the battery charge / discharge current detection device 100 and the ECU 300 is performed via the communication line. However, this communication is performed by wireless communication means not via the communication line. Also good. For example, the driver 174 shown in FIG. 2 may be replaced with a wireless driver using radio waves or an infrared driver using infrared rays. As a result, when the resistance value of the shunt resistor 210 becomes abnormally high or fusing occurs, the abnormality of the shunt resistor 210 is determined by communication regardless of whether or not the battery charge / discharge current detection device 100 floats from the ground. Can be notified. Of course, in this case, the ECU 300 side also needs to be equipped with a radio wave or infrared ray receiver.

DESCRIPTION OF SYMBOLS 100 Battery charge / discharge current detection apparatus 110 Power supply circuit 120 Ground (GND) switching part 130 Voltage amplification part 132, 142 Analog-digital converter (A / D)
140 Temperature detection unit 141 Thermal element 144 Shunt abnormality detection unit 150 Current value calculation unit 152 0 point correction unit 154 Storage unit 160 Alarm device 162 LED
164 Speaker 170 Communication processing unit 172 Communication controller 174 Driver 180 Microcomputer 182 CPU
184 ROM
186 RAM
188 I / O processor (I / O)
200 Battery 210 Shunt resistance 300 ECU

Claims (10)

In a battery charge / discharge current detection device for detecting a charge / discharge current of a battery mounted on a vehicle using a current detection resistor connected to a negative electrode side terminal of the battery,
Voltage detection means for detecting a voltage across the current detection resistor; current value detection means for detecting a charge / discharge current of the battery based on a voltage across the current detection resistor detected by the voltage detection means; and the current An abnormality detecting means for detecting the presence or absence of abnormality of the detection resistor, and connecting a negative side terminal for power connection to the negative side terminal of the battery,
The battery charge / discharge current detection device further comprising connection switching means for connecting a bypass means in parallel with the current detection resistor when an abnormality is detected by the abnormality detection means. In claim 1,
The connection switching means is connected between the current detection resistor and the voltage detection means, and the bypass means comprises two switches,
One switch is connected between the input terminals of the voltage detection means, and the other switch is connected between the one of the current detection resistors not connected to the negative terminal of the battery and the one switch. A battery charge / discharge current detector. In claim 2,
A battery charge / discharge current detection device using the connection switching means as a bypass means for the current detection resistor by turning on two switches as the bypass means together. In claim 2 or 3,
By turning on one of the switches as the bypass unit and turning off the other switch, a state in which the voltage across the current detection resistor is virtually zero is achieved. A battery charge / discharge current detecting device, further comprising a zero point correcting means for performing zero point correction. In claim 1,
By further switching the connection by the connection switching means, a zero point correction means for correcting the zero point of the current detection detection means is realized by realizing a state in which the voltage across the current detection resistor is virtually zero. A battery charge / discharge current detector. In claim 1,
The battery charge / discharge current detection device, wherein the abnormality detection means detects the presence or absence of abnormality based on a voltage across the current detection resistor detected by the voltage detection means. In claim 1,
Temperature detecting means for detecting the temperature of the current detection resistor,
The battery charge / discharge current detection device, wherein the abnormality detection means detects the presence or absence of abnormality based on the temperature detected by the temperature detection means. In claim 1,
A notification means for notifying the abnormality detected by the abnormality detection means to the outside;
The battery charging / discharging current detecting apparatus according to claim 1, wherein the notifying means notifies the external control device of an abnormality by wireless communication means not via a communication line. In claim 1,
A notification means for notifying the abnormality detected by the abnormality detection means to the outside;
The battery charging / discharging current detection device according to claim 1, wherein the notification means is an alarm device that visually or audibly reports an abnormality. In a battery charge / discharge current detection device for detecting a charge / discharge current of a battery mounted on a vehicle using a current detection resistor connected to a negative electrode side terminal of the battery,
Voltage detection means for detecting a voltage across the current detection resistor; current value detection means for detecting a charge / discharge current of the battery based on a voltage across the current detection resistor detected by the voltage detection means; and the current An abnormality detecting means for detecting the presence or absence of abnormality of the detection resistor, and connecting a negative side terminal for power connection to the negative side terminal of the battery,
The battery charge / discharge current detecting device further comprising first and second diodes having opposite polarities connected in parallel with the current detecting resistor.

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