JP7337567B2 - power supply - Google Patents

Description

The present invention relates to a power supply device.

Conventionally, as a power supply device, for example, in Patent Document 1, a plurality of batteries are mounted in an electric vehicle, a plurality of batteries are connected in parallel when running, and a plurality of batteries are connected in series when charging. A device is described.

JP 2018-85790 A

By the way, it is desired that the electric vehicle battery control device described in Patent Document 1 described above, for example, accurately detects the voltages of the plurality of batteries and charges the plurality of batteries to the maximum charge amount allowed. .

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a power supply device capable of properly charging and discharging the power of the first and second battery modules.

In order to solve the above-described problems and achieve the object, the power supply device according to the present invention includes a first battery module and a second battery module capable of charging and discharging electric power, and the first battery module and the second battery module. and a series circuit in which the first battery module and the second battery module are connected in series by controlling the switch, or the first battery module and the second battery module are connected in parallel. a control unit forming a parallel circuit connected to a series voltage detector for detecting the voltage of the series circuit including the first battery module and the second battery module; and the series voltage detector and a parallel voltage detector, which is a different voltage detector and detects the voltage of the parallel circuit including the first battery module and the second battery module.

In the above power supply device, the parallel voltage detector preferably has higher resolution than the serial voltage detector.

In the above power supply device, the control unit controls charging in the series circuit and the parallel circuit until charging rates of the first battery module and the second battery module reach an allowable upper limit threshold, and Preferably, the allowable upper limit threshold in the case of forming a circuit is higher than the allowable upper limit threshold in the case of forming the series circuit.

The power supply device according to the present invention can apply a voltage detector suitable for detecting the voltage of each of the series circuit and the parallel circuit, and can accurately detect the voltage of each of the series circuit and the parallel circuit. can. As a result, the power supply device can properly charge and discharge the power of the first and second battery modules.

FIG. 1 is a block diagram showing a configuration example of a power supply device according to an embodiment. FIG. 2 is a diagram showing error ranges by the total voltage detector and the single voltage detector according to the embodiment. FIG. 3 is a block diagram showing an example of voltage detection in a series circuit according to the embodiment. FIG. 4 is a block diagram showing an example of voltage detection of a parallel circuit according to the embodiment. FIG. 5 is a flowchart illustrating an operation example of the power supply device according to the embodiment;

A form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. In addition, various omissions, substitutions, or changes in configuration can be made without departing from the gist of the present invention.

[Embodiment]
A power supply device 1 according to an embodiment will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of a power supply device 1 according to an embodiment. FIG. 2 is a diagram showing error ranges W1 and W2 by the total voltage detector 40 and the single voltage detector 50 according to the embodiment. FIG. 3 is a block diagram showing an example of voltage detection of the series circuit P according to the embodiment. FIG. 4 is a block diagram showing an example of voltage detection of the parallel circuit Q according to the embodiment.

The power supply device 1 is mounted in a vehicle such as an electric vehicle (EV), a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), or the like. The power supply device 1 charges power supplied from an external charger and supplies the charged power to the motor M. As shown in FIG. The power supply device 1 is connected to, for example, a 350 kW (800 V) ultra-rapid charger 2, a 150 kW (400 V) rapid charger, an 11 kW (22 kW) home charger, and supplied with power. As shown in FIG. 1, the power supply device 1 includes a first battery 10 as a first battery module, a second battery 20 as a second battery module, a switch section 30, and a total battery as a serial voltage detector. It includes a voltage detection section 40 , a single voltage detection section 50 as a parallel voltage detector, and a control section 60 .

The first battery 10 is a storage battery that can charge and discharge electric power. The first battery 10 is, for example, a lithium ion battery with a maximum voltage of 500 V, and is configured by connecting a plurality of battery cells in series. The first battery 10 is connected in series or parallel to the second battery 20 via a battery connection switch 31, which will be described later.

The second battery 20 is a storage battery that can charge and discharge electric power. The second battery 20 is, for example, a lithium ion battery with a maximum voltage of 500 V, and is configured by connecting a plurality of battery cells in series. The second battery 20 has a capacity equivalent to that of the first battery 10 and is connected in series or parallel to the first battery 10 via a battery connection switch 31 .

The switch unit 30 has a switch 31 for battery connection, a switch 32 for charger connection, and a switch 33 for motor connection. The battery connection switch 31 switches the connection between the first battery 10 and the second battery 20, a series circuit P (see FIG. 3) in which the first battery 10 and the second battery 20 are connected in series, or a second A parallel circuit Q (see FIG. 4) is formed by connecting the first battery 10 and the second battery 20 in parallel. The battery connection switch 31 has switches 31a, 31b, 31c, and 31d. The switch 31a is arranged on the positive electrode side of the first battery 10 and has a fixed contact n1, a selective contact n2, and a selective contact n3. The fixed contact n1 is connected to the positive terminal of the first battery 10, the selective contact n2 is connected to the negative terminal of the second battery 20, and the selective contact n3 is connected to the rapid/domestic charger 3 and the positive terminal of the second battery 20. Connected.

The switch 31b is arranged on the negative electrode side of the first battery 10 and has a fixed contact n4, a selective contact n5, and a selective contact n6. A fixed contact n4 is connected to the negative pole of the first battery 10, a selective contact n5 is connected to the ultra-rapid charger 2 and the motor M, and a selective contact n6 is connected to the rapid/domestic charger 3 and the second battery 20. It is connected to the negative pole.

The switch 31c is arranged on the positive electrode side of the second battery 20 and has a fixed contact n7, a selective contact n8, and a selective contact n9. A fixed contact n7 is connected to the positive terminal of the second battery 20, a selective contact n8 is connected to the ultra-rapid charger 2 and the motor M, and a selective contact n9 is connected to the rapid/domestic charger 3 and the first battery 10. It is connected to the positive electrode.

The switch 31d is arranged on the negative electrode side of the second battery 20 and has a fixed contact n10, a selective contact n11, and a selective contact n12. The fixed contact n10 is connected to the negative pole of the second battery 20, the selective contact n11 is connected to the positive pole of the first battery 10, and the selective contact n12 is connected to the quick/home charger 3 and the negative pole of the first battery 10. Connected.

The charger connection switch 32 switches electrical connection between the super-rapid charger 2 and the rapid/domestic charger 3 and the first battery 10 and second battery 20 . The charger connection switch 32 has switches 32a, 32b, 32c, and 32d. The switches 32 a and 32 b are switches for switching electrical connection between the series circuit P including the first and second batteries 10 and 20 and the super rapid charger 2 . The switch 32 a is connected to the positive terminal of the second battery 20 in the series circuit P, and the switch 32 b is connected to the negative terminal of the first battery 10 in the series circuit P. In the power supply device 1, the connector of the ultra-rapid charger 2 is attached to the ultra-rapid inlet of the vehicle, and by turning on the switches 32a and 32b, the first and second batteries 10 and 20 forming the series circuit P are activated. Charge super fast. On the other hand, the power supply device 1 stops the super-rapid charging of the first and second batteries 10, 20 forming the series circuit P by turning off the switches 32a, 32b.

The switches 32 c and 32 d are switches for switching electrical connection between the parallel circuit Q including the first and second batteries 10 and 20 and the rapid/home charger 3 . The switch 32c is connected to the positive terminals of the first and second batteries 10, 20 in the parallel circuit Q, and the switch 32d is connected to the negative terminals of the first and second batteries 10, 20 in the parallel circuit Q. In the power supply device 1, for example, the connector of the rapid/home charger 3 is attached to the rapid inlet of the vehicle, and the switches 32c and 32d are turned on to form a parallel circuit Q of first and second batteries 10. , 20. On the other hand, the power supply device 1 stops rapid charging of the first and second batteries 10 and 20 forming the parallel circuit Q by turning off the switches 32c and 32d.

The motor connection switch 33 switches electrical connection between the first battery 10 and the second battery 20 and the motor M. As shown in FIG. The switch 33 for motor connection has switches 33a and 33b. The switches 33a and 33b are switches for switching electrical connection between the motor M and the series circuit P including the first battery 10 and the second battery 20 . The switch 33 a is connected to the positive terminal of the second battery 20 in the series circuit P, and the switch 32 b is connected to the negative terminal of the first battery 10 in the series circuit P. The power supply device 1 supplies power to the motor M from the first and second batteries 10 and 20 forming the series circuit P by turning on the switches 33a and 33b. On the other hand, the power supply device 1 stops power supply to the motor M from the first and second batteries 10 and 20 that form the series circuit P by turning off the switches 32a and 32b.

The total voltage detection section 40 detects the voltage of the series circuit P including the first battery 10 and the second battery 20 . The total voltage detector 40 has a lower resolution than the single voltage detector 50 and has a wider voltage detection range than the single voltage detector 50 . Here, the resolution is the ability to identify physical quantities such as voltage. In general, the higher the resolution, the finer the physical quantity can be detected, but the detection range of the physical quantity to be detected becomes narrower. On the other hand, if the resolution is low, the physical quantity cannot be detected finely, but the detection range of the physical quantity to be detected is widened. The total voltage detection unit 40 has a detection range of, for example, 0 V to 1280 V, a detection error of the total voltage detection unit 40, for example, ±10 V, and a charging rate margin of about 3%. Is required.

The total voltage detection unit 40 has one end connected to the positive electrode of the second battery 20 and the other end connected to the negative electrode of the first battery 10 in a series circuit P in which the positive electrode of the first battery 10 is connected to the negative electrode of the second battery 20 . It is connected to the. In the series circuit P, the total voltage detection unit 40 detects the potential difference between the positive electrode of the second battery 20 and the negative electrode of the first battery 10 in a wide voltage detection range with low resolution. The total voltage detection unit 40 is connected to the control unit 60 and outputs a voltage value representing the detected potential difference to the control unit 60 .

The single voltage detector 50 is a voltage detector different from the total voltage detector 40 and detects the voltage of the parallel circuit Q including the first battery 10 and the second battery 20 . The single voltage detection unit 50 has higher resolution than the total voltage detection unit 40 and has a narrower voltage detection range than the voltage detection range of the total voltage detection unit 40 . The single voltage detection unit 50 has a detection range of, for example, 0 V to 640 V, a detection error of the single voltage detection unit 50, for example, ±5 V, and a charging rate of about 1.5%. of margin is required. The single voltage detector 50 can reduce the charging rate margin by 1.5% compared to the total voltage detector 40 . In this way, if the margin of the charging rate can be reduced by 1.5%, the power supply device 1 can earn a driving distance of about 33 km in an EV capable of driving 500 km from a 100% fully charged state, for example.

The single voltage detection unit 50 has a parallel circuit Q in which the positive electrodes of the first battery 10 and the second battery 20 are connected together and the negative electrodes of the first battery 10 and the second battery 20 are connected together. and the positive electrodes of the second batteries 10, 20, and the other end is connected to the negative electrodes of the first and second batteries 10, 20. In the parallel circuit Q, the single voltage detection unit 50 detects the potential difference between the positive electrodes of the first and second batteries 10 and 20 and the negative electrodes of the first and second batteries 10 and 20 with high resolution and a narrow voltage detection range. do. Since the single voltage detection unit 50 has a higher resolution than the total voltage detection unit 40, the error range W1 of the voltage detection by the single voltage detection unit 50 is set to the voltage detection by the total voltage detection unit 40, as shown in FIG. It can be smaller than the error range W2. The single voltage detection unit 50 is connected to the control unit 60 and outputs a voltage value representing the detected potential difference to the control unit 60 .

The control section 60 controls the switch section 30 . The control unit 60 includes an electronic circuit mainly composed of a well-known microcomputer including a CPU, a ROM constituting a storage unit, a RAM, and an interface. The control unit 60 controls the motor connection switch 33 to switch electrical connection between the motor M and the series circuit P including the first battery 10 and the second battery 20 . The control unit 60 controls the charger connection switches 32 a and 32 b to switch the electrical connection between the series circuit P including the first and second batteries 10 and 20 and the super rapid charger 2 . The control unit 60 controls the charger connection switches 32 c and 32 d to switch the electrical connection between the parallel circuit Q including the first and second batteries 10 and 20 and the quick/home charger 3 . The control unit 60 controls the battery connection switch 31 to form a series circuit P in which the first battery 10 and the second battery 20 are connected in series, or a series circuit P in which the first battery 10 and the second battery 20 are connected in parallel. A parallel circuit Q is formed.

For example, when detecting that the connector of the super-rapid charger 2 is attached to the super-rapid inlet of the vehicle, the control unit 60 controls the battery connection switch 31 to connect the first battery 10 and the second battery. 20 are connected in series to form a series circuit P. Specifically, as shown in FIG. 3, the control unit 60 connects the fixed contact n7 and the selective contact n8, connects the fixed contact n10 and the selective contact n11, connects the selective contact n2 and the fixed contact n1, A series circuit P is formed by connecting the fixed contact n4 and the selective contact n5. Then, the control unit 60 turns on the charger connection switches 32a and 32b to electrically connect the super rapid charger 2 and the series circuit P to each other. Then, the control unit 60 charges the first and second batteries 10 and 20 forming the series circuit P with the power supplied from the super-rapid charger 2 . At this time, the control unit 60 controls charging until the charging rates of the first battery 10 and the second battery 20 reach the allowable upper limit threshold. Generally, in consideration of deterioration, damage, etc., a battery has a charging rate smaller than a charging rate of 100% (for example, about 80%) as an upper limit threshold for charging. Considering the error due to the resolution of the total voltage detection unit 40, the allowable upper limit threshold of the charging rate when the series circuit P is formed is a threshold smaller than the upper limit threshold (80%) during charging (for example, about 70%). ). The control unit 60 estimates the charging rate based on the voltage or the like detected by the total voltage detecting unit 40, and when the estimated charging rate reaches the allowable upper limit threshold for series (for example, about 70%), the charger is connected. The switches 32a and 32b for , are turned off to electrically disconnect the super-rapid charger 2 and the series circuit P to complete charging. Note that the control unit 60 turns off the motor connection switch 33 when the first and second batteries 10 and 20 are charged by the super-rapid charger 2 .

Further, when the control unit 60 detects that the connector of the quick/home charger 3 is attached to the quick inlet of the vehicle, the control unit 60 controls the battery connection switch 31 to A parallel circuit Q is formed by connecting the batteries 20 in parallel. Specifically, as shown in FIG. 4, the control unit 60 connects the fixed contact n1 and the selective contact n3, connects the fixed contact n7 and the selective contact n9, connects the fixed contact n4 and the selective contact n6, A parallel circuit Q is formed by connecting the fixed contact n10 and the selective contact n12. Then, the controller 60 turns on the charger connection switches 32c and 32d to electrically connect the rapid/home charger 3 and the parallel circuit Q. FIG. Then, the control unit 60 charges the first and second batteries 10 and 20 forming the parallel circuit Q with the power supplied from the quick/home charger 3 . At this time, the control unit 60 controls charging until the charging rates of the first battery 10 and the second battery 20 reach the allowable upper limit threshold. The permissible upper limit threshold in the case of forming the parallel circuit Q is set higher than the permissible upper limit threshold in the case of forming the series circuit P, for example, about 80%.

This is because the single voltage detection section 50 has a higher resolution than the total voltage detection section 40 , so that errors due to the resolution can be made smaller than the total voltage detection section 40 . As a result, the single voltage detection unit 50 can detect the voltage more accurately than the total voltage detection unit 40, so the allowable upper limit threshold for parallel use (for example, about 70%) is lower than the allowable upper limit threshold for series use (for example, about 70%) 80%) can be increased, and charging can be performed up to the upper limit threshold of charging. The control unit 60 estimates the charging rate based on the voltage or the like detected by the total voltage detecting unit 40, and when the estimated charging rate reaches an allowable upper limit threshold value for parallel use (for example, about 80%), the charger is connected. The switches 32c and 32d for are turned off to electrically disconnect the rapid/domestic charger 3 and the parallel circuit Q to complete the charging. When the first and second batteries 10 and 20 are charged by the quick/home charger 3, the control unit 60 turns off the motor connection switch 33. FIG.

Next, an operation example of the power supply device 1 will be described. Here, an operation example during battery charging will be described. FIG. 5 is a flow chart showing an operation example of the power supply device 1 according to the embodiment. As shown in FIG. 5, the control unit 60 of the power supply device 1 determines whether or not it is super rapid power supply (step S1). For example, when detecting that the connector of the super-rapid charger 2 is attached to the super-rapid inlet of the vehicle, the control unit 60 determines that the super-rapid power supply is being performed. If the super-rapid power supply is selected (step S1; Yes), the controller 60 forms a series circuit P (step S2). The control unit 60 forms a series circuit P by controlling, for example, the battery connection switch 31 to connect the first battery 10 and the second battery 20 in series.

Next, the control unit 60 performs battery charging (step S3). For example, the control unit 60 turns on the charger connection switches 32a and 32b to supply power supplied from the ultra-rapid charger 2 to the first and second batteries 10 forming the series circuit P. , 20. Next, the controller 60 detects the voltage of the series circuit P using the total voltage detector 40 (step S4). Next, the control unit 60 determines whether charging is completed (step S5). For example, when the charging rate based on the voltage or the like detected by the total voltage detecting section 40 reaches the allowable upper limit threshold for series (for example, about 70%), the control section 60 determines that the charging is completed. When the charging is completed (step S5; Yes), the control unit 60 terminates the ultra-rapid charging process. On the other hand, if the charging is not completed (step S5; No), the controller 60 returns to step S3 to charge the battery.

In the above-described step S1, if the super-rapid power supply is not performed (step S1; No), the control unit 60 determines whether it is fast charging or home charging (step S6). For example, when detecting that the connector of the rapid/home charger 3 is attached to the rapid inlet of the vehicle, the control unit 60 determines that rapid charging is being performed. If the charging is rapid charging or home charging (step S6; Yes), the controller 60 forms a parallel circuit Q (step S7). The control unit 60 forms a parallel circuit Q by controlling, for example, the battery connection switch 31 to connect the first battery 10 and the second battery 20 in parallel.

Next, the controller 60 charges the battery (step S8). The control unit 60, for example, turns on the charger connection switches 32c and 32d to supply the power supplied from the quick/home charger 3 to the first and second batteries 10 and 20 forming the parallel circuit Q. to charge. Next, the control unit 60 detects the voltage of the parallel circuit Q using the single voltage detection unit 50 (step S9). Next, the control unit 60 determines whether charging is completed (step S10). For example, when the charging rate based on the voltage or the like detected by the single voltage detection section 50 reaches an allowable upper limit threshold value for parallel (for example, about 80%), the control section 60 determines that charging is completed. When the charging is completed (step S10; Yes), the control unit 60 terminates the rapid charging or household charging. On the other hand, if the charging is not completed (step S10; No), the controller 60 returns to step S8 to charge the battery. In step S6 described above, if the charging is not rapid charging or household charging (step S6; No), the control unit 60 returns to step S1 described above to determine whether or not super-rapid power feeding is being performed.

As described above, the power supply device 1 according to the embodiment includes the first battery 10 and the second battery 20 capable of charging and discharging electric power, the battery connection switch 31, the control unit 60, and the total voltage detection unit 40. , and a single voltage detection unit 50 . A battery connection switch 31 switches connection between the first battery 10 and the second battery 20 . The control unit 60 controls the switch 31 for connecting the batteries to connect a series circuit P in which the first battery 10 and the second battery 20 are connected in series, or a parallel circuit in which the first battery 10 and the second battery 20 are connected in parallel. Form a circuit Q. Total voltage detector 40 detects the voltage of series circuit P including first battery 10 and second battery 20 . The single voltage detection section 50 is a voltage detection section different from the total voltage detection section 40 and detects the voltage of the parallel circuit Q including the first battery 10 and the second battery 20 .

Conventionally, a voltage detector for detecting the voltage of the series circuit P with low resolution is used to detect the voltage of the parallel circuit Q as well. It was necessary to have a sufficient margin for charging. On the other hand, in the power supply device 1 according to the embodiment, a voltage detector suitable for detecting voltages of the series circuit P and the parallel circuit Q can be applied. Since each voltage can be detected with high accuracy, it is not necessary to provide a sufficient charging margin in the case of the parallel circuit Q. As a result, the power supply device 1 can appropriately charge and discharge the electric power of the first and second batteries 10 and 20, thereby extending the travel distance of the vehicle.

In the power supply device 1 described above, the single voltage detection section 50 has higher resolution than the total voltage detection section 40 . With this configuration, the power supply device 1 can reduce the error due to the resolution of the single voltage detection section 50 compared to the total voltage detection section 40, and can increase the accuracy of the voltage detected by the single voltage detection section 50. Thereby, in the case of the parallel circuit Q, the power supply device 1 can accurately estimate the charging rates of the first and second batteries 10 and 20, and can reduce the charging margin.

In the power supply device 1, the control unit 60 controls the series circuit P and the parallel circuit Q so that the charging rates of the first battery 10 and the second battery 20 reach the allowable upper limit threshold. The permissible upper limit threshold when the parallel circuit Q is formed is higher than the permissible upper limit threshold when the series circuit P is formed. With this configuration, the power supply device 1 can bring the parallel allowable upper limit threshold closer to the charging upper limit threshold than the series allowable upper limit threshold. As a result, the power supply device 1 can increase the amount of charge in the case of the parallel circuit Q as compared to the case of the series circuit P.

[Modification]
Next, modifications of the embodiment will be described. In the above description, the first and second batteries 10 and 20 are lithium-ion batteries with a voltage of 500V, but are not limited to this and may be other batteries.

Although the power supply device 1 has explained an example in which power is supplied from the series circuit P to the motor M, it is not limited to this, and power may be supplied from the parallel circuit Q to the motor M. Electric power may be supplied to the motor M from either one of the two batteries 20 .

It is conceivable that the controller 60 controls the charging rates of the first battery 10 and the second battery 20 in the series circuit P and the parallel circuit Q so that they are discharged to the allowable lower limit threshold. In this case, the allowable lower limit threshold when the parallel circuit Q is formed may be lower than the allowable lower limit threshold when the series circuit P is formed.

When the super-rapid charger 2 is charging the first and second batteries 10 and 20 of the series circuit P and the allowable upper limit threshold for series is reached, the power supply device 1 charges the first and second batteries 10, 20 is switched to a parallel circuit Q, the voltage of the power supplied from the ultra-rapid charger 2 is stepped down, and the first and second batteries 10 and 20 of the parallel circuit Q are charged until reaching the allowable upper limit threshold for parallel use. It is also possible.

1 power supply device 10 first battery (first battery module)
20 second battery (second battery module)
31 Battery connection switch (changeover switch)
40 total voltage detector (series voltage detector)
50 single voltage detector (parallel voltage detector)
60 control unit P series circuit Q parallel circuit

Claims (3)

a first battery module and a second battery module capable of charging and discharging electric power;
a selector switch for switching connection between the first battery module and the second battery module;
Controlling the switch to form a series circuit in which the first battery module and the second battery module are connected in series, or a parallel circuit in which the first battery module and the second battery module are connected in parallel. Department and
a series voltage detector that detects the voltage of the series circuit including the first battery module and the second battery module;
a voltage detector for parallel, which is different from the voltage detector for series and detects the voltage of the parallel circuit including the first battery module and the second battery module;
A power supply device comprising: The power supply device according to claim 1, wherein the parallel voltage detector has higher resolution than the series voltage detector. The controller controls the series circuit and the parallel circuit so that the charging rates of the first battery module and the second battery module reach an allowable upper limit threshold, and
The power supply device according to claim 1 or 2, wherein the allowable upper limit threshold when forming the parallel circuit is higher than the allowable upper limit threshold when forming the series circuit.

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