JP5267050B2 - Battery level monitor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery remaining amount monitoring device that monitors a battery remaining amount by using a charging cable. <P>SOLUTION: The battery remaining amount monitoring device monitors a remaining amount of a battery mounted in a vehicle. The battery remaining amount monitoring device includes: a battery controller that detects a battery remaining amount so as to calculate battery state of charge information corresponding to the remaining amount and controls a charging current flowing in a charging power line in accordance with the battery state of charge information; and a current monitor part that monitors a charging current by a current sensor and calculates the battery remaining amount by detecting the battery state of charge information from the charging current so as to display the battery remaining amount. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a technique for monitoring a remaining battery level, and more particularly to a technique for monitoring a remaining battery voltage of a vehicle such as a plug-in hybrid vehicle (PHV) or an electric vehicle (EV).

Conventionally, vehicles such as PHV and EV have a mechanism to start charging when a power plug for charging is inserted into an outlet, and in order to complete charging in as short a time as possible, the charging system is charged until it is fully charged. In general, charging is performed at a maximum constant current that can be taken out of the battery. However, it takes time to charge the in-vehicle battery, and usually several hours are required from the state where the remaining amount of the in-vehicle battery is close to 0 to the full charge.
Therefore, there is a request that the vehicle user wants to check the remaining battery level outside the vehicle.

  According to Patent Document 1, a fuel cell and an electric double layer capacitor are connected in parallel to supply power. The DC / DC converter boosts the voltage of the fuel cell and the electric double layer capacitor and outputs electric power. An output switch is provided on the output path of the DC / DC converter. The control IC can turn on / off the output power by controlling the output switch. When the fuel cell is out of fuel or the fuel cell is abnormal, the control IC controls the output switch to intermittently change the output power. As a result, when connected to a mobile phone as a mobile electronic device, the user can recognize when the mobile phone's charging instruction lamp is blinking, indicating that the fuel has run out or the fuel cell is abnormal. There has been proposed a power supply device that can recognize an internal state such as a remaining battery level while improving the battery power.

According to Patent Document 2, it is related to a controller that controls a charger of an electric vehicle, and it is proposed that a charging state can be monitored indoors when charging. That is, it is composed of an in-vehicle controller that controls the charging state of the battery, a charger connected to the battery, and an indoor controller connected to the charger, and an abnormality during charging is also output to the indoor controller. Yes. However, the charger from the indoor controller requires a dedicated communication line.
According to Patent Document 3, the first communication system unit provided on the electric vehicle side and the second communication system unit provided on the power supply side for supplying charging electric power to the electric vehicle supply power. To communicate between the information equipment installed indoors and the information equipment installed in the electric vehicle by communicating via the power supply line for supplying charging power to the electric vehicle from the side Proposals have been made to simplify the construction of such communication systems.

However, in order to know the remaining amount of the in-vehicle battery, it is necessary to communicate with the battery controller on the vehicle side, and in addition to the power cable for charging, it is necessary to add a new communication device between the vehicle and the charging outlet. is there. As a result, there is a problem that the vehicle cost increases and the PHV becomes more expensive.
JP 2006-314156 A JP 9-233720 A JP 2004-222176 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a battery remaining amount monitoring device that monitors a remaining battery amount using a charging cable.

A battery remaining amount monitoring system that monitors the remaining amount of a battery mounted on a vehicle, which is one aspect, includes a charge controller, a current monitoring device, and a charging power line.
The charge controller detects the remaining amount of the battery, calculates battery charge state information corresponding to the remaining amount, and controls the grid current. The current monitor device monitors the grid current with a current sensor, detects the battery charge state information from the grid current, calculates the remaining battery level, and displays the remaining battery level. The charging power line connects the charge controller and the current monitoring device.

  In addition, the charge controller includes a battery remaining amount detecting unit that detects a remaining amount of the battery, a control unit that controls a system current corresponding to the battery charge state information, and an instruction from the control unit. A current switching unit that switches between interruption and conduction, and an impedance variable unit that is provided in a rectification unit for charging the battery and varies the amount of battery charging current according to an instruction from the control unit.

  Further, the current monitoring device includes the current sensor that detects the battery charge state information from the grid current, a battery remaining amount calculation unit that calculates a remaining amount of the battery corresponding to the battery charge state information, and the battery A battery remaining amount display unit that displays the remaining amount of the battery calculated by the remaining amount calculating unit.

  With the above configuration, the charge amount of the in-vehicle battery can be monitored on the charging outlet side during charging. In addition to the standard equipment and the battery cable for charging (+,-, ground), a new communication device is not added, which can be realized at low cost.

  It is possible to monitor the remaining amount of on-vehicle battery at home using the charging cable.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration when charging a PHV vehicle 1. The PHV vehicle 1 includes a battery 2 and a charge controller 3.

  For charging the battery 2, power is supplied from the electric wire 5 (for example, power transmission line) to the outlet 8 through the distribution board 6 arranged in the house 4 through the indoor wiring 7, and inserted into the outlet 8. This is performed by the charge controller 3 through the plug 9 and the charge plug 10.

  The remaining battery level is monitored by the current sensor 12, the remaining battery level calculation unit 13, and the remaining battery level display unit 14. The current flowing through the charging cable 11 is controlled according to battery charge state information described later generated by the charge controller 3. The current is monitored by the current sensor 12, and the battery charge state information is analyzed from the monitoring result to calculate the remaining battery level. Thereafter, the calculation result is notified to the battery remaining amount display unit 14.

  The battery charge state information calculated by the battery remaining amount calculation unit 13 is transmitted into the house 4 by means such as power line communication (PLC) or wireless communication so that the battery charge state can be monitored in the house 4. May be. The charging current may be direct current or alternating current.

  Note that a direct current after AC / DC conversion (rectification / smoothing) on the vehicle side is referred to as a charging current. A commercial AC current (AC100V, AC200V, etc.) supplied from the house side to the car by a charging cable is called a system current.

FIG. 2 is a block diagram showing configurations of the charge controller 3 and the current monitor device 26.
The charge controller 3 includes a control unit 21, a battery remaining amount detection unit 22, a rectification unit 23, and a current switching unit 24.

  The control unit 21 includes a CPU, a programmable device, and a memory. The control unit 21 controls each unit of the charge controller 3 and starts controlling the current opening / closing unit 24 and the impedance variable unit 25 according to a charge start command. Further, the control unit 21 issues a command to the impedance variable unit 25 based on the current control table corresponding to the remaining battery level stored in the memory, and controls the charging current at regular intervals.

The remaining battery level detection unit 22 calculates the remaining battery level from the voltage of the battery 2 and the like. The function of the battery remaining amount detection unit 22 may be provided in the control unit 21.
The current monitoring device 26 includes a remaining battery level calculation unit 13 and a remaining battery level display unit 14.

  The battery remaining amount calculation unit 13 includes, for example, a current / voltage converter (I / V converter), an analog / digital converter (A / D converter), a CPU for calculating time, and a memory, and includes a current sensor. The current value detected at 12 is converted by an analog / digital converter. Thereafter, based on the converted current value, the CPU calculates the remaining battery capacity based on the same current limit table stored in the control unit 21 stored in the memory.

The remaining battery level display unit 14 displays the digital data output from the remaining battery level calculation unit 13 as the remaining battery level.
(Current interruption time variable method)
The variable current interruption time method will be described.

  The variable current reduction time table shown in FIG. 3 is stored in a memory included in the control unit 21 and the remaining battery level calculation unit 13. The current reduction time variable table has data of “remaining battery amount” and “reduction time” (battery charge state information). For example, the “remaining battery level” indicates the remaining battery level in 10 stages, with 100% when the battery 2 is fully charged and 0% when there is no remaining battery level. The “reduction time” stores the time for controlling the current switching unit 24 so as to correspond to 10 stages of “battery remaining amount”. When the current switching unit 24 is a circuit breaker, the off time (breaking time) of the circuit breaker is stored. In the example of FIG. 3, when “remaining battery” is “0”%, “reduction time” is “1Δt” seconds, and when “remaining battery” is “10”%, “reduction time” is “2Δt” seconds. ... If the "remaining battery capacity" is "100"%, the "reduction time" is "11 [Delta] t" seconds. For example, Δt is 0.1 seconds.

The operation during battery charging will be described.
First, when the vehicle 1 and the current monitoring device 26 are connected by the charging cable 11, a charging start command is notified to the control unit 21.

Next, when the control unit 21 acquires the charge start command, the current switching unit 24 is brought into a chargeable state. For example, the circuit breaker is turned on.
Next, the control unit 21 obtains the remaining amount of the battery 2 from the remaining battery level detection unit 22, determines a time (battery charge state information) to cut off the charging current, and controls the current opening / closing unit 24 at a certain period T. .

  The battery remaining amount calculation unit 13 which monitors the charging current with the current sensor 12 measures the time when the charging current is cut off, searches the predetermined current reduction time variable table shown in FIG. 3 and selects the remaining amount. Then, the battery remaining amount display unit 14 is notified.

  4 is a diagram showing the charging current Ic on the vertical axis and the time on the horizontal axis from the start of charging to the completion of charging (system current, which is alternating current, is detected and rectified by a current sensor to be converted into a DC current. Diagram showing converted waveform). The current is controlled corresponding to the battery charge state information at every fixed period T (t1, t2,... Tm + 2). For example, T is 10 minutes.

  An example in the case of changing the current interruption time in method 1 of FIG. 5 will be described. When the remaining battery level is 80%, the charge controller 3 selects a reduction time corresponding to 80% of the current interruption time variable table (time when the charge current is interrupted in the variable current interruption time method) 9Δt, and the charging current interruption time A charging current in which 9Δt is cut off is generated.

The battery remaining amount calculation unit 13 detects the charging current interruption time of 9Δt from the charging current, and selects the battery remaining amount corresponding to 9Δt from the current reduction time variable table. Thereafter, the user is informed that the remaining battery level is 80%. Similarly, when the remaining battery level is 20%, 3Δt is detected, and the remaining battery level corresponding to 3Δt is selected from the current reduction time variable table.
(Current reduction time variable method)
The operation at the time of charging in the variable current reduction time method will be described.

First, the vehicle 1 and the current monitoring device 26 are connected by the charging cable 11 in the same manner as the variable current interruption time method.
Next, when the charge start command is transmitted to the control unit 21, the control unit 21 sets the current switching unit 24 in a state where it can be charged. For example, the circuit breaker is turned on.

  Next, the control unit 21 determines the time (battery charge state information) for obtaining the remaining battery level from the remaining battery level detection unit 22 and reducing the charging current, and controls the impedance variable unit 25 for each constant period T to control the current. Reduce.

  The remaining battery level calculation unit 13 that monitors the charging current by the current sensor 12 measures the time (battery charge state information) when the charging current is reduced, and stores the remaining time from the predetermined current reduction time variable table shown in FIG. The amount is calculated and notified to the battery remaining amount display unit 14.

  An example in the case of changing the current reduction time in method 2 in FIG. 5 will be described. The control unit 21 adjusts the impedance variable unit 25 to reduce the charging current for a period of 9Δt when the remaining battery level is 80%. For example, the impedance variable unit 25 is adjusted to reduce the current value so as to be a preset current value (0.6 Imax: 60% of the maximum value of the charging current).

The battery remaining amount calculation unit 13 detects the time during which the current during the charging current is 9Δt is reduced from the charging current, and selects the battery remaining amount corresponding to 9Δt from the current reduction time variable table. Similarly, when the remaining battery level is 20%, the time during which the current during the period of 3Δt is reduced is detected, and the remaining battery level corresponding to 3Δt is selected from the current reduction time variable table.
(Current triangle wave reduction time variable method)
The operation at the time of charging in the current triangular wave reduction time variable method will be described.

First, the vehicle 1 and the current monitoring device 26 are connected by the charging cable 11 as in the current interruption time variable method and the current reduction time variable method.
Next, when the charge start command is transmitted to the control unit 21, the control unit 21 sets the current switching unit 24 in a state where it can be charged. For example, the circuit breaker is turned on.

  Next, the control unit 21 determines the time (battery charge state information) during which the remaining battery level is obtained from the remaining battery level detection unit 22 and the charging current is reduced. To reduce the current.

  The remaining battery level calculation unit 13 that monitors the charging current by the current sensor 12 measures the time (battery charging state information) when the charging current is reduced, and based on a predetermined current reduction time variable table shown in FIG. The remaining amount is calculated and notified to the battery remaining amount display unit 14.

  An example in which the current triangular wave reduction time is varied will be described in the method 3 of FIG. When the remaining battery level is 80%, the charge controller 3 selects 9Δt based on the current reduction time variable table, and the impedance variable unit 25 gradually reduces the charge current during the period of 9Δt.

Similarly, when the remaining battery level is 20%, 3Δt is selected based on the current reduction time variable table, and the impedance variable unit 25 gradually reduces the charging current during the period of 3Δt.
Next, the battery remaining amount calculation unit 13 detects the time during which the charging current during the 9Δt or 3Δt period is gradually reduced from the charging current, and determines the remaining battery amount corresponding to 9Δt or 3Δt from the current reduction time variable table. select.

The slope for forming the current waveform in a triangular waveform at the time of reduction is shown by a straight line in the method 3 in FIG. 5, but is not particularly limited, and may be a slope represented by a polynomial expression.
(Current reduction variable method)
The current reduction amount variable method will be described.

  FIG. 6 shows a current reduction amount variable table used when changing the current reduction amount. The current reduction amount variable table is stored in the memory of the control unit 21 and the battery remaining amount calculation unit 13. The current reduction time variable table has data of “battery remaining amount” and “reduction rate” (battery charge state information). For example, the “remaining battery capacity” indicates the remaining battery capacity in 10 stages, with 100% when the battery 2 is fully charged and 0% when there is no remaining capacity. The “reduction rate” stores charging current reduction ratios corresponding to 10 stages of “battery remaining amount” for controlling the impedance variable unit 25 (charging current reduction rate with respect to the maximum value of charging current). . In the example of FIG. 6, if the “remaining battery amount” is “0”%, the “reduction rate” is “5”%, and if the “remaining battery rate” is “10”%, the “reduction rate” is “10”. %: If the “remaining battery amount” is “100”%, the “reduction rate” is “55”%.

The operation during charging will be described.
First, the vehicle 1 and the current monitoring device 26 are connected by the charging cable 11.
Next, when a charge start command is transmitted to the control unit 21 on the vehicle side, the control unit 21 puts the current switching unit 24 into a chargeable state. For example, the circuit breaker is turned on.

  Next, the control unit 21 determines the amount (rate) (battery charge state information) by which the remaining battery level is obtained from the remaining battery level detection unit 22 and the charging current is reduced, and the impedance variable unit 25 is controlled every fixed period T. To do.

  The battery monitoring unit 13 that monitors the charging current with a current sensor in the house-side current monitoring device measures the amount (rate) (battery charge state information) that the charging current is reduced, and is determined in advance as shown in FIG. The remaining amount is calculated from the current reduction amount variable table shown in FIG.

An example in which the current reduction amount is varied in the method 4 shown in FIG. 8 will be described. When the remaining battery level is 80%, the charging controller 3 reduces the charging current by 45% during Δt.
The battery remaining amount calculation unit 13 detects a portion where the charging current is reduced by 45% during Δt, and selects the remaining battery amount corresponding to the 45% reduction from the current reduction amount variable table. Similarly, when the remaining battery level is 20%, the remaining battery level corresponding to the charging current of 15% is selected from the current reduction amount variable table during Δt.
(Variable current reduction code)
The current reduction code variable method will be described.

  FIG. 7 shows a current reduction code variable table used when changing the current reduction code. The current reduction code variable table is stored in the memory of the control unit 21 and the remaining battery level calculation unit 13. The current reduction code variable table has data of “battery remaining amount” and “communication code” (battery charge state information). For example, the “remaining battery capacity” indicates the remaining battery capacity in 10 stages, with 100% when the battery 2 is fully charged and 0% when there is no remaining capacity. The “communication code” stores the time for controlling the current switching unit 24 or the impedance variable unit 25 so as to correspond to the 10 levels of the “battery remaining amount”, and the communication code is a code indicating the timing for performing the cutoff or reduction. .

  When the current switching unit 24 controls the charging current in order to generate the “communication code” corresponding to the remaining battery level, for example, the current switching unit 24 turns on and off the circuit breaker. The charging current is controlled in order to generate a “communication code” by turning on / off the circuit breaker every nΔt.

  When the charging current is controlled to generate the “communication code” by the impedance variable unit 25, the impedance variable unit 25 is adjusted to reduce the charging current to a preset current value every nΔt. The charging current is controlled to generate a “code”.

  In the example of FIG. 7, “communication code” is “10000” if “battery remaining amount” is “0”%, and “communication code” is “10001” if “battery remaining amount” is “10”%. ... If the “remaining battery amount” is “100”%, the “communication code” is “11010”.

The first 1 bit is a start bit.
The operation during charging will be described.
First, the vehicle 1 and the current monitoring device 26 are connected by the charging cable 11.

Next, when the charge start command is transmitted to the charge controller 3, the control unit 21 sets the current switching unit 24 in a chargeable state. For example, the circuit breaker is turned on.
Next, the control unit 21 obtains the remaining battery level from the remaining battery level detection unit 22, decides the time for cutting off or reducing the charging current, and controls the current opening / closing unit 24 or the variable impedance unit 25 at a certain period T.

  The battery remaining amount calculation unit 13 that monitors the charging current by the current sensor 12 measures the time when the charging current is reduced, calculates the remaining amount from a predetermined current reduction amount variable table shown in FIG. The remaining amount display unit 14 is notified.

  An example in which the current reduction code variable is performed in method 5 of FIG. 8 will be described. In FIG. 8, when the “communication code” is “1” for every fixed period Δt, the charging current is cut off or reduced, and when it is “0”, the charging current is controlled to be Imax.

When the remaining battery level is 80%, the charge controller 3 controls the charging current and sends the communication code “11000”.
The battery remaining amount calculation unit 13 detects the communication code “11000” from the charging current, searches the detected communication code from the current reduction amount variable table, and selects the corresponding battery remaining amount. Similarly, when the remaining battery level is 20%, the remaining battery level calculation unit 13 detects the communication code “10010” and selects the remaining battery level corresponding to the communication code “10010” from the current reduction amount variable table.

The battery charge state information may be coded with the battery charge time together with the remaining battery charge code.
With the above-described configuration, a new communication device is not required on the vehicle side, and the remaining amount of the in-vehicle battery can be monitored on the charging outlet side using only the charging cable of the PHV or EV vehicle.

In addition to the remaining battery level, the required charging time can be monitored as information.
In addition to the standard equipment and the battery cable for charging (+,-, ground), a new communication device is not added to the vehicle side, which can be realized at low cost.

  Note that the battery charge state information is transmitted to the house only at the start of charging, and then the grid current is monitored for a preset time, and is integrated using the current value detected during the monitoring period. The remaining battery level can also be estimated based on the above.

  The battery charge state information received by the current monitor device may be transmitted into the house by means of PLC or wireless communication so that the battery charge state information can be monitored (displayed) in the house.

  In addition, a current monitor BOX or the like may be provided in the middle of the cable for connecting the outlet on the house side and the charging port of the vehicle, and battery charge state information transmitted from the charge controller or the like may be received and displayed.

Moreover, you may charge not only alternating current but using a direct current using a solar cell etc. for charge.
The present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the gist of the present invention.

It is the figure which showed the structure in the case of charging a vehicle. It is a block diagram which shows the structure of a battery controller and a current monitor part. It is a figure which shows the table used with a current interruption time variable system, a current reduction time variable system, and a current triangular wave reduction time variable system. It is a figure which shows having controlled the charging current according to the battery charge condition information. It is a figure which shows the charging current controlled according to the battery charge state information of methods 1-3. It is a figure which shows the table used with an electric current reduction amount variable system. It is a figure which shows the table used with a current reduction code variable system. It is a figure which shows the charging current controlled according to the battery charge state information of methods 4 and 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Battery 3 Charge controller 4 House 5 Electric wire 6 Distribution board 7 Indoor wiring 8 Outlet 9 Plug 10 Charge plug 11 Charge cable 12 Current sensor 13 Battery remaining amount calculation part 14 Battery remaining amount display part 21 Control part 22 Battery remaining amount Detection unit 23 Rectification unit 24 Current switching unit 25 Impedance variable unit 26 Current monitoring device

Claims (6)

A battery remaining amount monitoring system for monitoring a remaining amount of a battery mounted on a vehicle,
A charge controller that detects a remaining amount of the battery, calculates battery charge state information corresponding to the remaining amount, and controls a system current;
A current monitor that monitors the grid current with a current sensor, detects the battery charge state information from the grid current, calculates the remaining battery level, and displays the remaining battery level;
A charging power line connecting the charge controller and the current monitoring device ,
The charge controller is
A battery remaining amount detection unit for detecting the remaining amount of the battery;
A controller that controls the grid current in response to the battery charge state information;
A current switching unit for switching off and switching on the grid current according to an instruction from the control unit;
An impedance variable unit that is provided in a rectifying unit for charging the battery and varies a battery charging current amount according to an instruction from the control unit ;
A battery remaining capacity monitoring system comprising: The current monitoring device includes:
The current sensor for detecting the battery charge state information from the grid current which is a commercial AC current supplied to the vehicle ;
A battery remaining amount calculation unit for calculating a remaining amount of the battery corresponding to the battery charge state information;
A remaining battery level display unit for displaying the remaining battery level calculated by the remaining battery level calculation unit;
The battery remaining amount monitoring system according to claim 1, comprising: The battery charge state information is
By controlling the current switching unit or the impedance variable unit in accordance with the remaining amount of the battery, the charging current reduction amount is made constant and the charging current reduction time is varied, or the charging current reduction is performed. 3. The battery remaining amount monitoring system according to claim 1, wherein the remaining amount of battery information is information for gradually increasing the amount of charging current and varying the reduction time of the charging current. The battery charge state information is
3. The information according to claim 1, wherein the impedance variable unit is varied in accordance with the remaining amount of the battery, the charge current reduction time is constant, and the charge current reduction amount is variable. The battery remaining amount monitoring system described. The battery charge state information is
3. The information according to claim 1, wherein the impedance variable unit is varied in accordance with the remaining amount of the battery, the charging current reduction time is constant, and the charging current reduction code is varied. The battery remaining amount monitoring system described. The battery remaining charge monitoring system according to any one of claims 2 to 4 , wherein the battery charge state information is generated at a constant cycle and is the charge current waveform corresponding to the battery charge state information.

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