JP4035913B2 - Charged state detection device for assembled battery and vehicle control device using the device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an assembled battery charge state detection device particularly suitable for an electric vehicle or a hybrid vehicle, and a vehicle control device including the detection device.
[0002]
[Prior art]
The drive battery of an electric vehicle has an assembled battery structure in which several tens to several tens of volt battery modules are connected in series, and this is housed in one package and mounted on the vehicle body as a battery pack. . In a hybrid vehicle and an electric vehicle equipped with such a battery pack, accurately grasping the remaining capacity of the assembled battery, the degree of deterioration, etc. is one of the factors for improving the running and charging performance.
[0003]
Therefore, conventionally, the battery voltage is measured for each battery module or for several battery modules, and is used as one of the parameters for grasping the remaining capacity and the state of deterioration of the assembled battery. These battery voltage (hereinafter abbreviated as individual voltage) detection means are incorporated in the battery pack and insulate other controls from the high voltage.
[0004]
The individual voltage detecting means transfers the measured individual voltage data to a controller mounted on a traveling control unit that performs vehicle control and traveling control by serial communication or the like, and the controller determines the battery state.
[0005]
[Problems to be solved by the invention]
However, such a system configuration has a problem that a time difference occurs in the sampling time of the individual voltage with respect to the sampling time of the total current by the current sensor. In the controller for determining the battery state, the sampling time of the individual voltage = the time when the data is transferred, but the actual individual voltage data is the data at the time when it was previously sampled by the individual voltage detecting means. There is a problem that the total current data and the individual voltage data are not synchronized, and the calculation accuracy of the battery state deteriorates.
[0006]
Therefore, the present invention provides an electric vehicle capable of grasping a more accurate battery state by realizing individual voltage and total current synchronous detection in the assembled battery individual voltage detection means and the total current detection means. The purpose is to provide a hybrid vehicle.
[0007]
[Means for Solving the Problems]
According to the state of charge detection device of the present invention as set forth in claim 1, voltage detection is carried out to individually detect each module voltage of a large number of battery modules that are connected in series with each other and constitute a high voltage assembled battery. A circuit, a current detection circuit that detects a total current of the assembled battery, and a battery state calculation unit that calculates a charge state of the assembled battery according to the voltage and current detected by the voltage detection circuit and the current detection circuit; In a state of charge detection device for an assembled battery comprising :
The current detection circuit detects a total current of the assembled battery by a current sensor provided between the assembled battery and a power converter connected to the assembled battery, and the battery calculation unit outputs The voltage detection timing and the current detection timing are synchronized by performing voltage detection by the voltage detection circuit and current detection by the current detection circuit based on the signal to be detected .
[0008]
According to this, a more accurate battery state can be detected by detecting the voltage and current in synchronization.
[0009]
According to another aspect of the present invention, the battery module and the voltage detection circuit are housed in one package.
[0010]
According to the vehicle control device of claim 3, a plurality of battery modules that are connected in series to form a high-voltage assembled battery, and voltage detection that individually detects each module voltage of the battery module sequentially. A battery pack having a circuit, a current detection circuit for detecting a total current of the assembled battery, and the voltage detection circuit and the current detection circuit calculate a state of charge of the assembled battery according to the detected voltage and current. includes a state of charge detecting device of the assembled battery having a battery state calculating means, depending on the charge state of the battery detected by the charging state detection device, and a driving source control circuit for controlling the drive source of the vehicle, the The current detection circuit detects a total current of the assembled battery by a current sensor provided between the assembled battery and a power converter connected to the assembled battery,
The voltage detection timing and the current detection timing are synchronized by performing voltage detection by the voltage detection circuit and current detection by the current detection circuit based on a signal output from the battery calculation means .
[0011]
According to this, by detecting the voltage and current at the same timing, it is possible to properly control the drive source of the vehicle by detecting the accurate state of charge of the assembled battery.
[0012]
According to a fourth aspect of the present invention, the current detection circuit, the charge state detection circuit, and the drive source control circuit are housed in a different package from the battery pack.
[0013]
Furthermore, in the vehicle control apparatus according to claim 5, the voltage detected by the voltage detection circuit is transmitted to the charge state detection circuit by communication.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the configurations of the following embodiments, and can naturally be configured using a replaceable known circuit.
[0015]
【Example】
An embodiment of the vehicle control apparatus of the present invention will be described with reference to FIGS.
[0016]
FIG. 1 is a schematic diagram of the system configuration of the present invention. Reference numeral 19 denotes a battery for traveling, which has an assembled battery structure in which several tens of battery modules having a voltage of about several volts to several tens of volts are connected in series.
[0017]
Reference numeral 1 denotes an individual voltage detection means that insulates the battery module 19 of the running battery from other control systems, measures the voltages V1 to Vn of each battery module 19 individually, and outputs the measurement data to the signal 201 by serial communication. is doing. The individual voltage detection means 1 will be described later.
[0018]
A battery pack 30 includes the traveling battery 19 and the individual voltage detecting means 1 in one package and is mounted on the vehicle as a traveling power supply unit.
[0019]
Reference numeral 40 denotes a traveling motor, which is driven by converting electric power stored in the traveling battery 19 with 50 traveling inverters. And the motor 40 for driving | running | working which is a drive source of an electric vehicle or a hybrid vehicle is driven.
[0020]
Reference numeral 60 denotes current detection means, which measures the total current Ib of the battery module flowing through the traveling battery 19 using a magnetic balance type current sensor or the like, and outputs a voltage as a signal 601.
[0021]
Reference numeral 70 denotes a travel control unit, which is a travel control device composed of a travel inverter 50, a current detection means 60, a controller 80, and the like, and is a package different from the battery pack 30.
[0022]
Reference numeral 80 denotes a controller for controlling this system, which inputs various sensor signals of the vehicle (for example, an accelerator sensor 84, a brake sensor 85, a shift sensor 86, etc.), and controls the traveling inverter 50 by a microcomputer to drive the vehicle. Driving of the vehicle is controlled by driving the motor 40.
[0023]
The battery state calculation means 81 in the controller 80 detects the state of charge of the assembled battery based on signals from the current detection means 60 and the individual voltage detection means 1. Since this detection method is generally known, a description thereof will be omitted.
[0024]
Further, the vehicle control means 82 calculates the torque required to drive the vehicle from the information on the battery charge state from the battery state calculation means 81 and the signals of the sensors 84, 85, 86 described above. For the torque calculation method, see, for example, Japanese Patent Application Laid-Open No. 11-6449.
[0025]
Further, the torque control device 83 performs current control of the traveling inverter 50 according to the torque calculated by the vehicle control means 82. Moreover, when charging the battery 19 for driving | running | working, it cooperates with the charger outside or inside this system, and performs charge control. Then, the battery module voltages V1 to Vn and the total current Ib of the traveling battery 19 are detected via the signal 201 and the signal 601, and the remaining capacity and the deterioration degree of the traveling battery 19 are calculated and monitored. Accordingly, the running ability and charging performance of the system are improved by limiting the running capacity and controlling the charging current accordingly.
[0026]
And the battery pack 301 is demonstrated based on FIG. 3 and FIG. 4 below. It is a block diagram which shows the voltage detection apparatus of the assembled battery which converts each module voltage of the assembled battery 19 into a digital signal, and is the assembled battery 19, the differential type voltage detection circuits 201-220, and the A / D conversion circuits 5-8. A photocoupler element 20a is shown.
[0027]
FIG. 4 is a block diagram showing an embodiment of a battery monitoring device using the voltage detection device of FIG.
[0028]
1 is a CPU for controlling the voltage of a battery, 2 is a selector circuit for distributing a clock signal made of a demultiplexer (hereinafter also referred to as a clock signal selector circuit), and 3 is a selector circuit for distributing a control signal made of a demultiplexer (hereinafter, called (Also referred to as a control signal selector circuit) 4 is a selector circuit for selecting a digital signal comprising a multiplexer (hereinafter also referred to as a data selector circuit), 5 to 10 are A / D conversion circuits, and 201 to 220 and 13 are differential types. A voltage detection circuit, 14 is an analog amplifier circuit, 15 is a current sensor, 101 to 120 are battery modules (also simply referred to as modules) of the assembled battery 19. However, in FIG. 4, the battery modules 106 to 120, the differential voltage detection circuits 206 to 220, and the A / D conversion circuits 6 to 8 are not shown.
[0029]
Each of the battery modules 101 to 120 is formed by cascading 12 unit cells. Battery module 101 has the highest module voltage, and battery module 120 has the lowest module voltage. Reference numeral 20 denotes a serial signal line group for connecting the selector circuits 2 to 4 and the A / D conversion circuits 5 to 10. In this embodiment, each signal line is a photocoupler (for example, 20a) for protection of the CPU 1. have. Each of the A / D conversion circuits 5 to 10 is a switching input type A / D conversion circuit with 5 channel inputs, and the channels of the A / D conversion circuits 5 to 10 are synchronously switched by an input switching signal. .
[0030]
As can be seen from FIG. 4, the module voltage of the module 101 is converted into a signal voltage with respect to a predetermined reference potential 1 by the differential voltage detection circuit 201 and then A / D converted by the A / D conversion circuit 5. The Similarly, the module voltage of the module 102 is converted into a signal voltage with respect to a predetermined reference potential 1 by the differential voltage detection circuit 202 and then A / D converted by the A / D conversion circuit 5. The module voltage 103 is converted to a signal voltage corresponding to a predetermined reference potential 1 by the differential voltage detection circuit 203 and then A / D converted by the A / D conversion circuit 5, and the module voltage of the module 104 is converted. Is converted to a signal voltage corresponding to a predetermined reference potential 1 by the differential voltage detection circuit 204 and then A / D converted by the A / D conversion circuit 5, and the module voltage of the module 105 is detected by the differential voltage detection. The signal is converted into a signal voltage corresponding to a predetermined reference potential 1 by the circuit 205 and then A / D converted by the A / D conversion circuit 5.
[0031]
Similarly, the module voltages of the battery modules 106 to 110 are input to the A / D conversion circuit 6 through the differential voltage detection circuits 206 to 210, and the module voltages of the battery modules 111 to 115 are different. The dynamic voltage detection circuits 211 to 215 are input to the A / D conversion circuit 7, and the module voltages of the battery modules 116 to 120 are input to the A / D conversion circuit 8 through the differential voltage detection circuits 216 to 220. Is done.
[0032]
The total voltage of the assembled battery 19 is converted into a signal voltage with respect to a predetermined common ground potential by the differential voltage detection circuit 13 and then A / D converted by the A / D conversion circuit 9, and the current of the assembled battery 19 is amplified by an amplifier circuit. A / D conversion is performed by the A / D conversion circuit 19 through 14.
[0033]
Outputs of the A / D conversion circuits 5 to 10 are selected in time sequence by the data selector circuit 4 and read into the CPU 1 as a signal SIN.
[0034]
The A / D conversion circuits 5 to 10 are synchronous operation serial output type A / D conversion circuits, and the conversion data, that is, the serial digital signal is output in synchronization with the clock pulse input after the digital signal is determined.
[0035]
More specifically, the A / D conversion circuit 5 has an analog input terminal for inputting an analog signal, a data output terminal for outputting a digital signal as a serial signal, and a control command input for receiving a control command as a serial signal. Terminal and a clock pulse input terminal to which a clock pulse for synchronization is input. When a read command is input to the control command input terminal, an analog signal is read and then the next clock pulse is input. As a result, an 8-bit serial digital signal is output. The other A / D conversion circuits 6 to 10 have the same structure.
[0036]
Next, the differential voltage detection circuits 201 to 220 for detecting each module voltage of the assembled battery 19 will be described with reference to FIG.
[0037]
In this embodiment, a total of 240 single cells constituting the assembled battery 19 are divided into 20 battery modules 101 to 120 connected in cascade, and the battery modules 101 to 105 are further connected to a first voltage. The battery modules 106 to 110 constitute a second voltage detection block, the battery modules 111 to 115 constitute a third voltage detection block, and the battery modules 116 to 120 constitute a detection block. A fourth voltage detection block is configured.
[0038]
The first voltage detection block has a reference potential 1 that is a first reference potential, the second voltage detection block has a reference potential 2 that is a second reference potential, and the third voltage detection block has a first potential. The fourth voltage detection block has a reference potential 4 that is a fourth reference potential.
[0039]
In this embodiment, the reference potential 1 is set to the lower terminal voltage of the battery module 103 (the higher terminal voltage of the battery module 104). The lower terminal voltage of the third battery module from the high potential side in the block (the higher terminal voltage of the second battery module from the lower side) is set.
[0040]
That is, in this embodiment, the reference potential of each differential voltage detection circuit in the same voltage detection block (a constant potential applied to one end of the input side resistor network) is made equal, and each voltage detection block has Different reference potentials 1 to 4 are applied. Further, each of the reference potentials 1 to 4 is set to an intermediate potential of each battery module in the voltage detection block (a value as close as possible to an intermediate value between the highest terminal voltage and the lowest terminal voltage). The terminal voltage of the battery module is used as 1-4.
[0041]
Next, FIG. 2 shows a timing chart when determining the individual voltage and total current data of the present invention. In this timing chart, the timing is controlled by a microcomputer incorporated in the controller 80.
[0042]
First, in order to synchronize the sampling of the battery module voltages V1 to Vn and the total current Ib, the controller 80 outputs a pulse signal having a predetermined cycle to the signal 211 as a synchronization signal (see FIG. 2A) and this pulse signal. Accordingly, the total current Ib is detected via the signal 601 (see FIG. 2E).
[0043]
Furthermore, the individual voltage detection means 1 measures the battery module voltages V1 to Vn in accordance with the timing of the signal 211 in FIG. 2A (see FIG. 2B), and the measurement data is transferred to the signal 201 by serial communication. (See FIG. 2C).
[0044]
Further, the controller 80 updates the battery module voltages V1 to Vn (see FIG. 2D) and the total current Ib in accordance with the reception of serial communication data of the battery module voltages V1 to Vn performed via the signal 201. Data is updated (see FIG. 2 (f)).
[0045]
With the above control, even in a system configuration in which the individual voltage detection means of the assembled battery and the current detection means of the total current are separated, the synchronous detection of the individual voltage and the total current can be realized, and a more accurate battery state can be achieved. It is possible to provide an electric vehicle or a hybrid vehicle that can be grasped and can properly drive the vehicle drive source (travel motor 40).
[Brief description of the drawings]
FIG. 1 is a system diagram of a vehicle control device of the present invention.
FIG. 2 is a timing chart showing voltage and current detection according to the present invention.
FIG. 3 is a block diagram showing an assembled battery voltage detection device that converts each module voltage of the assembled battery 19 into a digital signal.
4 is a block circuit diagram showing an embodiment of a battery monitoring device for an assembled battery using the voltage detection device for the assembled battery of FIG. 3. FIG.
[Explanation of symbols]
1 is an individual voltage detection means, 19 is an assembled battery, 30 is a battery pack, 40 is a motor for traveling, 50 is an inverter circuit, 60 is a current detection means, 70 is a travel control unit, 80 is a controller, 81 is a battery state calculation means .

Claims (5)

A voltage detection circuit that individually detects each module voltage of a large number of battery modules that are connected in series to form a high-voltage assembled battery, and a current detection circuit that detects the total current of the assembled battery; In a battery pack state of charge detection device comprising battery state calculation means for calculating the state of charge of the battery pack according to the voltage and current detected by the voltage detection circuit and the current detection circuit,
The current detection circuit detects a total current of the assembled battery by a current sensor provided between the assembled battery and a power converter connected to the assembled battery, and the battery calculation unit outputs An assembled battery charge state detection device , wherein voltage detection time and current detection time are synchronized by performing voltage detection by the voltage detection circuit and current detection by the current detection circuit based on a signal to be detected.   2. The battery charge state detection device according to claim 1, wherein the battery module and the voltage detection circuit are housed in one package. A battery pack having a number of battery modules that are connected in series to form a high-voltage assembled battery, and a voltage detection circuit that individually detects each module voltage of the battery module individually; Charging an assembled battery comprising: a current detection circuit for detecting a total current; and a battery state calculation means for calculating a charge state of the assembled battery according to the voltage and current detected by the voltage detection circuit and the current detection circuit. A state detection device, and a drive source control circuit that controls the drive source of the vehicle according to the state of charge of the battery detected by the charge state detection device;
The current detection circuit detects a total current of the assembled battery by a current sensor provided between the assembled battery and a power converter connected to the assembled battery, and the battery calculation unit outputs A vehicle control device that synchronizes voltage detection time and current detection time by performing voltage detection by the voltage detection circuit and current detection by the current detection circuit based on a signal to be detected .   4. The vehicle control device according to claim 3, wherein the current detection circuit, the charge state detection circuit, and the drive source control circuit are housed in a different package from the battery pack. apparatus.   5. The vehicle control device according to claim 4, wherein the voltage detected by the voltage detection circuit is transmitted to the charge state detection circuit by communication.

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