JP2021052453A - Conversion device and conversion system - Google Patents

Abstract

To suppress a breakdown voltage rise of an apparatus in a configuration in which a battery outputs a high voltage.SOLUTION: A conversion device 30 comprises a first voltage conversion unit 31 and a plurality of second voltage conversion units 32. The first voltage conversion unit 31 performs a first conversion operation for performing voltage conversion upon a voltage applied to a first power path 61A and applying an output voltage to a second power path 62A, and a second conversion operation for performing voltage conversion upon the voltage applied to the second power path 62A and applying an output voltage to the first power path 61A. Each of the plurality of second voltage conversion units 32 is electrically connected to a battery 20 in such a manner that a voltage within a range of a breakdown voltage of the second voltage conversion unit 32 is inputted.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a conversion device and a conversion system.

Electric vehicles have problems of increasing the cruising range and shortening the battery charging time. In view of these issues, it is predicted that the battery capacity will increase and the battery pressure will increase (high voltage) in the future.

By increasing the pressure of the battery, it is expected that the quick charge output will be improved. On the other hand, when the pressure of the battery is increased, it is necessary to increase the withstand voltage of the device (for example, DC / DC converter) connected to the battery. In Patent Document 1 below, a technique for switching the connection of a plurality of batteries in an electric vehicle, connecting them in series during charging and connecting them in parallel during traveling, thereby shortening the charging time and avoiding high withstand voltage of the device. Has been proposed.

Japanese Unexamined Patent Publication No. 2018-85790 Japanese Unexamined Patent Publication No. 2019-47677

In the technique disclosed in Patent Document 1, since a plurality of batteries are connected in parallel when the vehicle is running, it is possible to suppress a high withstand voltage of the device connected to the batteries. However, if the structure is such that the vehicle is always connected in parallel when the vehicle is running as in the technique of Cited Document 1, there is a problem that the battery cannot run in a state of outputting a high voltage.

In order to enable the battery to run in a state where it outputs a high voltage, it is necessary to make the device connected to the battery a high withstand voltage device corresponding to the high voltage of the battery. However, when such a high withstand voltage device is used, there arises a problem that the device mounted on the vehicle becomes large.

An object of the present disclosure is to provide a technique for suppressing high withstand voltage of a device in a configuration in which a battery outputs a high voltage, and realizing high efficiency and redundancy.

The conversion device according to the first aspect of the present disclosure is
A conversion device that converts the power supplied from a battery equipped with multiple power storage units.
A first voltage converter electrically connected to a first power path, which is a path for supplying power from the battery,
A plurality of second voltage converters electrically connected to the battery via a conductive path,
With
The first voltage conversion unit performs a first conversion operation of converting the voltage applied to the first power path into a voltage and applying an output voltage to the second power path, and a voltage applied to the second power path. The second conversion operation of converting and applying the output voltage to the first power path is performed.
Each of the plurality of second voltage conversion units is electrically connected to a part of the battery so that a voltage within the withstand voltage range of the second voltage conversion unit is input.

The conversion device according to one aspect of the present disclosure can suppress high withstand voltage of the device in a configuration in which the battery outputs a high voltage, and can realize high efficiency and redundancy.

FIG. 1 is a block diagram schematically illustrating a conversion system including the conversion device according to the first embodiment of the present disclosure. FIG. 2 is a block diagram illustrating a part of the conversion system of FIG. FIG. 3 is a schematic diagram schematically illustrating a vehicle equipped with the conversion system of FIG. FIG. 4 is a circuit diagram showing a specific configuration example of the second DC / DC converter used in the conversion system of FIG. FIG. 5 is a block diagram showing a specific example different from that of FIG. 2 for a part of the conversion system of FIG.

The embodiments of the present disclosure are listed and illustrated below. The features [1] to [11] shown below may be combined in any way within a consistent range.

[1] A conversion device that converts electric power supplied from a battery including a plurality of power storage units, and is a first voltage conversion electrically connected to a first electric power path which is a path for supplying electric power from the battery. The first voltage conversion unit includes a unit and a plurality of second voltage conversion units that are electrically connected to the battery via a conductive path, and the first voltage conversion unit converts a voltage applied to the first power path into a voltage. Then, a first conversion operation of applying an output voltage to the second power path and a second conversion operation of voltage-converting the voltage applied to the second power path and applying an output voltage to the first power path are performed. Each of the plurality of second voltage conversion units is a conversion device that is electrically connected to a part of the battery so that a voltage within the withstand voltage range of the second voltage conversion unit is input.

The conversion device of the above [1] can be configured to realize bidirectional voltage conversion with the battery side as the input side and the output side by the first voltage conversion unit, and can perform voltage conversion by each of the plurality of second voltage conversion units. It can be compatible with the configuration. Moreover, since each of the plurality of second voltage converters is electrically connected to a part of the battery so that a voltage within the withstand voltage range of the second voltage converter is input, the battery outputs a high voltage. Even with the configuration, it is possible to suppress the high withstand voltage of the device. Further, in the above conversion device, since a plurality of output paths based on voltage conversion can be secured by a plurality of second voltage conversion units, redundancy can be achieved.

[2] A plurality of connection target parts are predetermined in the battery, and each of the connection target parts is a different part in the battery, and each of the plurality of second voltage conversion units is a plurality of connection targets. The conversion device according to [1], which is provided corresponding to each of the parts, and each input voltage corresponding to the voltage across each of the plurality of connection target parts is input to each of the plurality of second voltage conversion units. ..

The conversion device described in the above [2] can be connected without concentrating the power supply sources of the plurality of second voltage conversion units, and each second voltage conversion unit can be connected from the corresponding connection target portion. It can be operated independently based on power.

[3] A connection portion is provided such that at least a part thereof is interposed in the path between the battery and the auxiliary machine, and the connection portion inputs a voltage within the withstand voltage range of the auxiliary machine to the auxiliary machine. The conversion device according to [1] or [2], which makes the battery and the auxiliary machine conductive.

The conversion device described in the above [3] can be made conductive so as to input a voltage within the withstand voltage range of the auxiliary machine even if the battery outputs a high voltage.

[4] The connection unit includes a connection circuit that constitutes an energization path between the battery and the auxiliary machine, and a connection control unit that controls the connection circuit, and a candidate portion serving as a power supply source is provided. A plurality of the connection circuits are defined in advance in the battery, and the connection circuit has a configuration in which the energization path is switched so as to select a supply source for supplying electric power to the auxiliary machine from the plurality of candidate portions, and the connection control unit is configured. The conversion device according to [3], wherein the power supply source selected by the connection circuit is determined based on the respective states of the plurality of candidate sites.

The conversion device described in [4] above has a configuration in which a part of the battery can be selected as a power supply source for the auxiliary equipment, and even if the battery outputs a high voltage, the high withstand voltage of the auxiliary equipment is suppressed. Can be done. Moreover, since the conversion device can select the power supply source for the auxiliary machine from a plurality of candidate parts, the power supply source can be switched as needed, and redundancy can be realized.

[5] The conversion device according to [4], wherein the connection circuit has a plurality of semiconductor relays and selects a power supply source based on the on / off state of each of the plurality of semiconductor relays.

Since the conversion device described in [5] above can switch the power supply source to the auxiliary machine by turning on / off the semiconductor relay, it has a long life, can be switched with good responsiveness, and is switched by a connection circuit that is less likely to be a noise source. Can be realized.

[6] The charging device includes a charging device and a conversion control unit, and the charging device applies a DC voltage based on the power from the outside when power is supplied from the outside of the vehicle on which the conversion device is mounted. When applied to the two power paths, the conversion control unit causes the first voltage conversion unit to perform the second conversion operation when the charging device applies the DC voltage to the second power path [1] to [1]. 5] The conversion device according to any one of.

In the conversion device described in [6] above, when power is supplied from the outside of the vehicle, a relatively low DC voltage is applied to the second power path by the charging device, and this DC voltage is applied to the first voltage conversion unit. Can boost the voltage and supply power for charging to the battery. In particular, the conversion device can also serve as the first voltage conversion unit without using a dedicated boost converter to boost the DC voltage applied by the charging device when charging based on the power supply from the charging device. Therefore, the device configuration can be simplified.

The conversion device is not limited to the configuration of the above [6]. In the conversion device according to any one of [1] to [5] provided with a charging device, the charging device is provided from the outside when power is supplied from the outside of the vehicle on which the conversion device is mounted. A DC voltage based on the electric power of the above may be applied to the first electric power path. Alternatively, in the conversion device according to any one of [1] to [5] provided with a charging device, the charging device is external when power is supplied from the outside of the vehicle equipped with the conversion device. A DC voltage based on the electric power from the power storage unit may be applied to each of the plurality of power storage units. In this case, the conversion device includes a switching circuit capable of switching the connection destination (charging current supply destination) from the charging device to each of the plurality of power storage units, and a switching control unit capable of controlling the switching circuit. Is desirable.

[7] The battery has a configuration in which a plurality of the power storage units are connected in series, and each of the plurality of the power storage units is each of the plurality of connection target portions [1] to [6]. The conversion device according to one.

The conversion device described in [7] above makes it possible to output a higher voltage from the battery by connecting a plurality of power storage units in series, and inputs a voltage based on each power storage unit to each second voltage conversion unit. It is possible to suppress the increase in pressure resistance.

[8] The conversion device according to any one of [1] to [7], wherein the rated voltage of each of the connection target parts is smaller than the withstand voltage of any of the plurality of second voltage conversion units.

The conversion device described in [8] above can more reliably prevent a voltage exceeding the withstand voltage of the second voltage conversion unit from being input to the second voltage conversion unit.

[9] A conversion system including the battery and the conversion device according to any one of [1] to [8] that converts the electric power supplied from the battery.

The conversion system described in the above [9] is a system capable of suppressing a high withstand voltage of the device in a configuration in which the battery outputs a high voltage.

[10] The conversion system according to [9], further including an inverter in which electric power is supplied from the battery via the second power path, and a motor in which electric power is supplied via the inverter.

The conversion system described in the above [10] is a system capable of operating the motor based on the electric power output from the battery at a high voltage, and at the same time, suppressing the increase in the withstand voltage of the device.

[11] A vehicle including a load to which electric power converted or transmitted by the conversion system is supplied, and the conversion system according to any one of [9] and [10].

The vehicle described in the above [11] is a vehicle capable of suppressing a high withstand voltage of the device in a configuration in which the battery outputs a high voltage.

<First Embodiment>
As shown in FIGS. 1 and 2, the conversion system 4 according to the embodiment of the present disclosure includes a power supply system 10, a load 7, a high-voltage auxiliary machine 8, a motor 12, an inverter 14, a capacitor 16, a switch unit 18, and the like. The power supply system 10 includes a battery 20, a converter 30, a first DC / DC converter 31, a plurality of second DC / DC converters 32A and 32B, a low-voltage battery 24, a connection unit 36, a switching unit 50, an in-vehicle charger 28, and the like. The power supply system 10 is a system capable of outputting electric power to a motor 12, a load 7, a high-voltage auxiliary machine 8, and the like. As shown in FIG. 3, the conversion system 4 is mounted on the vehicle 1 and functions as an in-vehicle conversion system. As shown in FIGS. 2 and 3, the vehicle 1 includes a conversion system 4 and a load to which electric power converted or transmitted by the conversion system 4 is supplied, and the load is a load 7, a high-voltage auxiliary machine 8, or the like. ..

The battery 20 includes a plurality of power storage units 20A and 20B. The battery 20 functions as a power supply device. Each of the plurality of power storage units 20A and 20B is a battery unit composed of chargeable and dischargeable storage batteries. The battery 20 is a high-voltage battery unit capable of outputting a voltage larger than that of the low-voltage battery 24, and is also referred to as a high-voltage battery unit below. Each of the power storage units 20A and 20B is, for example, a 400V specification battery unit. The 400V specification means that the charge voltage and output voltage ratings are 400V. The plurality of power storage units 20A and 20B are connected in series. Each of the power storage units 20A and 20B may be a unit of a plurality of batteries, or may be a single battery. As the batteries constituting the power storage units 20A and 20B, known batteries such as lithium ion batteries can be adopted, but the types of batteries are not limited.

The conversion device 30 is a device that converts the electric power supplied from the battery 20. The conversion device 30 includes at least the first DC / DC converter 31 and the second DC / DC converters 32A and 32B. In addition to the first DC / DC converter 31 and the second DC / DC converters 32A and 32B, the conversion device 30 includes a connection circuit 40, a control unit 48, a switching unit 50, an in-vehicle charger 28, a first power path 61, and a second power path. 62, wiring 64A, 64B, 66A, 66B, 68A, 68B and the like are included.

The first DC / DC converter 31 corresponds to an example of the first voltage conversion unit. The first DC / DC converter 31 is composed of a known isolated bidirectional DCDC converter. The first DC / DC converter 31 is electrically connected to the first power path 61, which is a path for supplying power from the battery 20. Further, the first DC / DC converter 31 is electrically connected to the second power path 62, which is a path for supplying power to the motor 12 side. The first power path 61 includes a power path 61A which is a conductive path on the high potential side and a power path 61B which is a conductive path on the low potential side. The second power path 62 includes a power path 62A which is a conductive path on the high potential side and a power path 62B which is a conductive path on the low potential side. One end of the power path 61A is electrically connected to the high potential side electrode having the highest potential in the battery 20. The electric power path 61A has a potential similar to that of the high potential side electrode. The other end of the power path 61A is electrically connected to the first DC / DC converter 31. One end of the power path 61B is electrically connected to the low potential side electrode having the lowest potential in the battery 20. The electric power path 61B has a potential similar to that of the low potential side electrode. The other end of the power path 61B is electrically connected to the first DC / DC converter 31. The first DC / DC converter 31 performs a first conversion operation of converting the voltage applied to the first power path 61 to a desired output voltage of the voltage of the second power path 62. Further, the first DC / DC converter 31 performs a second conversion operation of converting the voltage applied to the second power path 62 to a desired output voltage of the voltage of the first power path 61. Specifically, the voltage of the first power path 61 is the potential difference between the power lines 61A and 61B. Specifically, the voltage of the second power path 62 is the potential difference between the power lines 62A and 62B. The first conversion operation is a step-down operation in which a relatively high first voltage applied to the first power path 61 is stepped down and a relatively low second voltage is applied to the second power path 62. The first voltage is, for example, a DC voltage of about 800 V. The second voltage is, for example, a DC voltage of about 400 V. The second conversion operation is a boosting operation in which a relatively low third voltage applied to the second power path 62 is boosted and a relatively high fourth voltage is applied to the first power path 61. The third voltage is, for example, a DC voltage of about 400 V, which is about the same as the second voltage. The fourth voltage is, for example, a DC voltage of about 800 V, which is about the same as the first voltage. The specific examples of the above-mentioned input voltage and output voltage in each of the first conversion operation and the second conversion operation are merely examples, and are not limited to the above-mentioned values.

Each of the plurality of second DC / DC converters 32A and 32B corresponds to an example of the second voltage conversion unit. The second DC / DC converters 32A and 32B are electrically connected to the battery 20 via the wirings 64A, 64B, 66A and 66B. Wiring 64A, 64B, 66A, 66B corresponds to an example of a conductive path. The second DC / DC converters 32A and 32B are composed of, for example, known isolated DCDC converters. Specifically, both the second DC / DC converters 32A and 32B are step-down DC / DC converters that convert a relatively high voltage supplied from the battery 20 into a voltage lower than this supply voltage (for example, 12V). It is a DC converter. As shown in FIG. 2, the second DC / DC converters 32A and 32B both supply the converted voltage to the low-voltage battery 24.

The second DC / DC converter 32A is electrically connected to the wirings 64A and 64B, which are paths for supplying electric power from a part of the battery 20. The second DC / DC converter 32A is also electrically connected to the wirings 68A and 68B electrically connected to the low voltage battery 24. One end of the wiring 64A is electrically connected to the electrode on the high potential side of the power storage unit 20A forming a part of the battery 20, and has the same potential as the electrode on the high potential side of the power storage unit 20A. The electric power path 61A and the wiring 64A have the same potential. The other end of the wiring 64A is electrically connected to the second DC / DC converter 32A. One end of the wiring 64B is electrically connected to the electrode on the low potential side of the power storage unit 20A, and has the same potential as the electrode on the low potential side of the power storage unit 20A. The other end of the wiring 64B is electrically connected to the second DC / DC converter 32A. The second DC / DC converter 32A performs a voltage conversion operation of converting the voltage of the wirings 64A and 64B into a voltage and making the voltage of the wirings 68A and 68B a desired output voltage. The voltage of the wirings 64A and 64B is the voltage applied to the wirings 64A and 64B, and is the potential difference between the wirings 64A and 64B. The voltage of the wirings 68A and 68B is a voltage applied to the wirings 68A and 68B, and is a potential difference between the wirings 68A and 68B. Specifically, the voltage conversion operation of the second DC / DC converter 32A is a step-down in which a relatively high DC voltage applied to the wirings 64A and 64B is stepped down and a relatively low DC voltage is applied to the wirings 68A and 68B. It is an operation. The potential difference between the wirings 64A and 64B, which is the input voltage in the voltage conversion operation of the second DC / DC converter 32A, is the voltage across the power storage unit 20A, for example, about 400V. The potential difference between the wirings 68A and 68B, which is the output voltage in the voltage conversion operation of the second DC / DC converter 32A, is, for example, 12V.

The second DC / DC converter 32B is electrically connected to the wirings 66A and 66B, which are paths for supplying electric power from a part of the battery 20. The second DC / DC converter 32B is also electrically connected to the wires 68A and 68B electrically connected to the low voltage battery 24. One end of the wiring 66A is electrically connected to the electrode on the high potential side of the power storage unit 20B forming a part of the battery 20, and has the same potential as the electrode on the high potential side of the power storage unit 20B. The wiring 64B and the wiring 66A have the same potential. The other end of the wiring 66A is electrically connected to the second DC / DC converter 32B. One end of the wiring 66B is electrically connected to the electrode on the low potential side of the power storage unit 20B, and has the same potential as the electrode on the low potential side of the power storage unit 20B. The other end of the wiring 66B is electrically connected to the second DC / DC converter 32B. The second DC / DC converter 32B performs a voltage conversion operation of converting the voltage of the wirings 66A and 66B into a voltage and making the voltage of the wirings 68A and 68B a desired output voltage. The voltage of the wirings 66A and 66B is a voltage applied to the wirings 66A and 66B, and is a potential difference between the wirings 66A and 66B. Specifically, the voltage conversion operation of the second DC / DC converter 32B is a step-down in which a relatively high DC voltage applied to the wirings 66A and 66B is stepped down and a relatively low DC voltage is applied to the wirings 68A and 68B. It is an operation. The potential difference between the wirings 66A and 66B, which is the input voltage in the voltage conversion operation of the second DC / DC converter 32B, is the voltage across the power storage unit 20B, for example, about 400V. The potential difference between the wirings 68A and 68B, which is the output voltage in the voltage conversion operation of the second DC / DC converter 32B, is, for example, 12V.

Specific examples of the above-mentioned input voltage and output voltage when operating the second DC / DC converters 32A and 32B are merely examples, and are not limited to the above-mentioned values.

Each of the second DC / DC converters 32A and 32B is electrically connected to a part of the battery 20 so that a voltage within the range of each withstand voltage is input. The withstand voltage of each of the second DC / DC converters 32A and 32B is a predetermined operation guarantee voltage, which is a predetermined fixed value. In this configuration, a plurality of power storage units 20A and 20B are connected in series to form the battery 20, and each of the plurality of power storage units 20A and 20B is a plurality of connection target parts. The connection target portion is a portion that supplies a DC voltage based on the voltage across itself as an input voltage to the second voltage conversion unit corresponding to itself. For example, the power storage unit 20A, which is one connection target part, is a part that supplies a DC voltage based on the voltage across itself as an input voltage to the second DC / DC converter 32A corresponding to itself. Further, the power storage unit 20B, which is another connection target part, is a part that supplies a DC voltage based on the voltage across itself as an input voltage to the second DC / DC converter 32B corresponding to itself. The rated voltage of each of the storage units 20A and 20B, which is the connection target portion, is smaller than the withstand voltage of any of the plurality of second DC / DC converters 32A and 32B. In the above description, the "DC voltage based on the voltage across itself" may be a DC voltage having the same magnitude as the voltage across itself, and is a DC voltage slightly lower than the voltage across itself. There may be.

Specifically, the second DC / DC converter 32A is electrically connected to the power storage unit 20A so that a voltage within the withstand voltage range of the second DC / DC converter 32A is input. The second DC / DC converter 32B is electrically connected to the power storage unit 20B so that a voltage within the withstand voltage range of the second DC / DC converter 32B is input. Each of the second DC / DC converters 32A and 32B has, for example, an input voltage of 400V. The withstand voltage of each of the second DC / DC converters 32A and 32B is higher than the voltage across each of the power storage units 20A and 20B when fully charged, and is higher than the voltage across the battery 20 when fully charged (for example, 800V). Is also a low voltage. The voltage across the battery 20 when fully charged is the voltage across the entire storage units 20A and 20B connected in series. A voltage is applied between the wiring 64A and the wiring 64B connected to each input terminal of the second DC / DC converter 32A within a range not exceeding the voltage across the power storage unit 20A when fully charged. The voltage across the power storage unit 20A when fully charged is a voltage within the withstand voltage range of the second DC / DC converter 32A, and is, for example, 400V. A voltage is applied between the wiring 66A and the wiring 66B connected to each input terminal of the second DC / DC converter 32B within a range not exceeding the voltage across the power storage unit 20B when fully charged. The voltage across the power storage unit 20B when fully charged is a voltage within the withstand voltage range of the second DC / DC converter 32B, and is, for example, 400V.

As shown in FIG. 2, the output terminals of the second DC / DC converters 32A and 32B are connected in parallel and connected to the input terminal of the low voltage battery 24. Specifically, the output terminals on the high potential side of the second DC / DC converters 32A and 32B are electrically connected to the electrodes on the high potential side of the low voltage battery 24 via the wiring 68A. The low-potential side output terminals of the second DC / DC converters 32A and 32B are electrically connected to the low-potential side electrodes of the low-voltage battery 24 via the wiring 68B. The output terminal of the low voltage battery 24 is electrically connected to the load 7. The low-voltage battery 24 is charged by the voltage input from the second DC / DC converters 32A and 32B, and supplies electric power to the load 7.

FIG. 4 shows the configuration of the second DC / DC converter 32A. The specific configuration of the second DC / DC converter 32B is the same as the configuration of the second DC / DC converter 32A shown in FIG. The second DC / DC converter 32A includes a capacitor 80, a DC / AC converter 82, a transformer 84, and a rectifying unit 86. The DC / AC converter 82 includes switch elements 82A, 82B, 82C, 82D constituting a full bridge circuit. The input terminals of the DC / AC converter 82 are connected to both terminals of the capacitor 80. The output terminals of the DC / AC converter 82 are connected to both terminals of the primary winding of the transformer 84. The DC / AC converter 82 converts the DC voltage input from the capacitor 80 side into an AC voltage and outputs it to the primary winding of the transformer 84. The rectifying unit 86 includes a switch element 86A, a switch element 86B, an inductor 86C, and a capacitor 86D. The input side of the rectifying unit 86 is connected to both terminals of the secondary winding of the transformer 84. The secondary winding of the transformer 84 is a coil of the center tap. The rectifying unit 86 rectifies the AC voltage generated in the secondary winding of the transformer 84, smoothes it, and outputs it as a DC voltage. The first DC / DC converter 32A converts the high DC voltage input from the capacitor 80 side into the low DC voltage and supplies it to the low voltage battery 24. Each switch element constituting the first DC / DC converter 32A is composed of, for example, a FET (Field Effect Transistor) having a recirculation diode. The switch element may be a semiconductor element other than the FET, for example, a GaN-HEMT (High Electron Mobility Transistor) or the like.

As shown in FIG. 1, the inverter 14 is configured as a circuit that supplies electric power for driving the motor 12 to the motor 12. The pair of input terminals of the inverter 14 are electrically connected to the power lines 62A and 62B, respectively, via the switches 18A and 18B constituting the switch unit 18. The electric power supplied from the battery 20 can be supplied to the inverter 14 via the first electric power path 61, the first DC / DC converter 31, the second electric power path 62, and the switch unit 18. The output terminal of the inverter 14 is connected to the input terminal of the motor 12. The motor 12 is an electric drive device such as a main engine motor. Electric power is supplied to the motor 12 via the inverter 14. The output voltage of the battery 20 is about 800 V, but the inverter 14 is supplied with a voltage of about 400 V stepped down by the first DC / DC converter 31. The inverter 14 generates electric power for driving the motor 12 based on the input electric power corresponding to 400 V. That is, the inverter 14 supplies the high voltage required to rotate the motor 12 at high speed during high-speed running. A capacitor 16 is provided between the conductive path connected to the input terminal on one side of the inverter 14 and the conductive path connected to the input terminal on the other side.

Each of the switches 18A and 18B constituting the switch unit 18 is composed of, for example, a semiconductor relay or an electromagnetic relay. Both the switches 18A and 18B are turned on when an on instruction is given from the external device, and are turned off when an off instruction is given from the external device. The control device that controls the switches 18A and 18B may be the control unit 48 or another device. The switch 18A is interposed between the conductive path connected to the input terminal on one side of the inverter 14 and the power path 62A, and switches the path between them between the conductive state and the non-conductive state. The switch 18B is interposed between the conductive path connected to the input terminal on the other side of the inverter 14 and the power path 62B, and switches the path between them between the conductive state and the non-conductive state. When the switches 18A and 18B are in the off state, power is not supplied from the second power path 62 side to the inverter 14 side. When both the switches 18A and 18B are in the ON state, power can be supplied from the second power path 62 side to the inverter 14 side when the first conversion operation is being performed by the first DC / DC converter 31.

The high-voltage auxiliary machine 8 is a high-voltage load to which a high voltage is applied. The high-voltage auxiliary machine 8 corresponds to an example of the auxiliary machine. The high-voltage auxiliary machine 8 may be, for example, an air conditioner, a heater, or the like, or may have a load other than these. The high voltage applied to the high-voltage auxiliary machine 8 is, for example, 400 V, which is higher than the low voltage applied to the load 7. The high-voltage auxiliary machine 8 has a configuration capable of conducting conduction with the wirings 64A, 64B, 66A, 66B via the connection circuit 40, and electric power can be supplied from any of the power storage units 20A, 20B via the connection circuit 40.

The connection portion 36 is a device in which at least a part thereof is interposed in the path between the battery 20 and the high-voltage auxiliary machine 8. The connection portion 36 may conduct the battery 20 and the high-voltage auxiliary machine 8 so as to input a voltage within the withstand voltage range of the high-voltage auxiliary machine 8 to the high-voltage auxiliary machine 8. The withstand voltage of the high-voltage auxiliary machine 8 is a predetermined operation guarantee voltage, which is a predetermined fixed value. The connection unit 36 includes a connection circuit 40 and a control unit 48.

The connection circuit 40 is a circuit that constitutes an energization path between the battery 20 and the high-voltage auxiliary machine 8. The connection circuit 40 has a plurality of switches 41, 42, 43, 44. The plurality of switches 41, 42, 43, 44 are all semiconductor relays. In this configuration, a plurality of candidate sites serving as power supply sources for the high-voltage auxiliary machine 8 are predetermined in the battery 20. Specifically, the power storage unit 20A is defined as the first candidate site, and the power storage unit 20B is defined as the second candidate site. The connection circuit 40 is configured to switch the energization path so that the supply source for supplying electric power to the high-voltage auxiliary machine 8 is selected from a plurality of candidate sites. The connection circuit 40 selects a power supply source when supplying power to the high-voltage auxiliary machine 8 based on the on / off state of each of the plurality of switches 41, 42, 43, and 44. When the switches 41, 42 are turned on and the switches 43, 44 are turned off in the plurality of switches 41, 42, 43, 44, the wiring 64A conducts with one input terminal of the high-voltage auxiliary machine 8, and the wiring 64B becomes It conducts with the other input terminal of the high voltage auxiliary machine 8. In this case, the power storage unit 20A, which is the first candidate site, is selected, and the voltage across the power storage unit 20A is supplied to the high-voltage auxiliary machine 8. When the switches 43, 44 are turned on and the switches 41, 42 are turned off in the plurality of switches 41, 42, 43, 44, the wiring 66A conducts with one input terminal of the high-voltage auxiliary machine 8, and the wiring 66B. Conducts with the other input terminal of the high voltage auxiliary machine 8. In this case, the power storage unit 20B, which is the second candidate site, is selected, and the voltage across the power storage unit 20B is supplied to the high-voltage auxiliary machine 8. One end of the switch 41 is electrically connected to the wiring 64A, and the other end of the switch 41 is electrically connected to the other end of the switch 43 and one input terminal. One end of the switch 42 is electrically connected to the wiring 64B, and the other end of the switch 42 is electrically connected to the other end of the switch 44 and the other input terminal. One end of the switch 43 is electrically connected to the wiring 66A, and the other end of the switch 43 is electrically connected to the other end of the switch 41 and one input terminal. One end of the switch 44 is electrically connected to the wiring 66B, and the other end of the switch 44 is electrically connected to the other end of the switch 42 and the other input terminal.

The control unit 48 is a device that controls the connection circuit 40. The control unit 48 corresponds to an example of the connection control unit. The control unit 48 is a device having a calculation function and an information processing function, and is composed of, for example, an information processing device such as a microcomputer. The control unit 48 controls switching of a plurality of switches 41, 42, 43, 44. If the control unit 48 appropriately controls the switching of the plurality of switches 41, 42, 43, 44, the voltage across the power storage unit 20A is input to the input terminal of the high-voltage auxiliary machine 8 and the input of the high-voltage auxiliary machine 8. It is possible to switch between a state in which the voltage across the power storage unit 20B is input to the terminal. Further, the control unit 48 can also control the first DC / DC converter 31 and the second DC / DC converters 32A and 32B. The control unit 48 corresponds to an example of a conversion control unit.

The in-vehicle charger 28 corresponds to an example of a charging device. The in-vehicle charger 28 is electrically connected to the power lines 62A and 62B. The vehicle-mounted charger 28 applies a DC voltage based on the external power to the second power path 62 when power is supplied to the vehicle-mounted charger 28 from the outside of the vehicle 1 on which the conversion device 30 is mounted. obtain. Specifically, for example, when the in-vehicle charger 28 receives electric power from commercial electric power supplied to a home, the in-vehicle charger 28 converts this electric power and applies a desired DC voltage to the electric power paths 62A and 62B. The DC voltage applied to the power paths 62A and 62B by the vehicle-mounted charger 28 is, for example, 400V. The in-vehicle charger 28 may include a charging device for wireless power transmission.

The switching unit 50 is a circuit that switches the connection destination when the battery 20 is charged by the electric power supplied from a quick charging device such as a charging stand. The high potential side terminal having the highest potential in the battery 20 is electrically connected to the power line 58 via the switch 53. The power line 58 is a power line that can be electrically connected to one of the power lines of the quick charging device when the quick charging device is connected to the vehicle 1. When the switch 53 is on, the power path 61A and the power line 58 are in a conductive state, and when the switch 53 is off, the power path 61A and the power line 58 are in a non-conducting state. The low potential side terminal having the lowest potential in the battery 20 is connected to the power line 59 via the switch 54. The power line 59 is a power line that can be electrically connected to the other power line of the quick charging device when the quick charging device is connected to the vehicle 1. When the switch 54 is on, the power path 61B and the power line 59 are in a conductive state, and when the switch 54 is off, the power path 61B and the power line 59 are in a non-conducting state. The power line 62A is electrically connected to the power line 58 via the switch 51. When the switch 51 is on, the power path 62A and the power line 58 are in a conductive state, and when the switch 51 is off, the power path 62A and the power line 58 are in a non-conducting state. The power line 62B is electrically connected to the power line 59 via the switch 52. When the switch 52 is on, the power path 62B and the power line 59 are in a conductive state, and when the switch 52 is off, the power path 62B and the power line 59 are in a non-conducting state. The control device that controls the switches 51, 52, 53, 54 may be the control unit 48 or another device. Hereinafter, an example in which the control unit 48 controls the switches 51, 52, 53, 54 will be described.

As shown in FIG. 3, the above-mentioned conversion system 4 is mounted on a vehicle such as a PHEV (Plug-in Hybrid Electric Vehicle) or an EV (Electric Vehicle). The conversion system 4 can charge the battery (high-voltage battery unit) 20 and the low-voltage battery 24 with AC power supplied from an external AC power source. The conversion system 4 supplies the electric power of the battery (high-voltage battery unit) 20 and the low-voltage battery 24 to the motor 12, the auxiliary machine load 6, and the like when the vehicle is running. The auxiliary machine system load 6 is an accessory device necessary for operating an engine, a motor, and the like, and mainly includes a cell motor, an alternator, a radiator cooling fan, and the like. The auxiliary machine system load 6 may include a load 7 (lighting, wiper drive unit, navigation device, etc.) and a high-pressure auxiliary machine 8 (air conditioner, heater, etc.).

The control for connecting the high-voltage auxiliary machine 8 is as follows. In this configuration, the control unit 48 functions as an example of the connection control unit. The control unit 48 determines the power supply source selected by the connection circuit 40 based on each state of the plurality of candidate parts (that is, each state of the plurality of power storage units 20A and 20B) at least while the vehicle 1 is traveling. To do. Specifically, a battery sensor 26 is provided, and the battery sensor 26 can detect the values of the output voltages (voltages across the ends) of the power storage units 20A and 20B and output the values to the control unit 48. The control unit 48 compares the output voltages (voltages across the ends) of the power storage units 20A and 20B at least while the vehicle 1 is traveling, and selects the one having the larger output voltage as the power supply source to the high-voltage auxiliary machine 8. For example, if the power storage unit 20A has a larger output voltage (voltage across) than the power storage unit 20B, the switches 41 and 42 are turned on and the switches 43 and 44 are turned off, and the power based on the power storage unit 20A is supplemented with high voltage. Supply to machine 8. Conversely, if the power storage unit 20B has a higher output voltage (voltage across) than the power storage unit 20A, the switches 43 and 44 are turned on and the switches 41 and 42 are turned off, and the power based on the power storage unit 20B is increased to a high voltage. It is supplied to the auxiliary machine 8. The conversion device 30 can perform the control for determining the power supply source other than while the vehicle 1 is running. For example, the conversion device 30 may perform the control when the vehicle 1 is in the starting state.

The controls for quick charging are as follows. In the following description, the case where a relatively high voltage is supplied from the quick charging device to perform charging is described as "first quick charging". The "relatively high voltage" in the first rapid charging is a voltage that exceeds the voltage specifications of the power storage unit 20A and the power storage unit 20B. Specifically, the "relatively high voltage" is a voltage that exceeds the withstand voltage of the second DC / DC converters 32A and 32B, and is, for example, 800V. Further, when charging is performed by supplying a voltage relatively lower than that at the time of the first quick charging from the quick charging device, it is described as "second quick charging". The "relatively low voltage" in the second rapid charging is, for example, a voltage equal to or lower than the voltage specifications of the power storage unit 20A and the power storage unit 20B. Specifically, the "relatively low voltage" is a voltage equal to or lower than the withstand voltage of the second DC / DC converters 32A and 32B, and is, for example, 400V.

When the above "first quick charge" is performed, for example, the control unit 48 controls the switches 53 and 54 to be in the on state and the switches 51 and 52 to be in the off state. When the switching unit 50 is switched in this way, a DC voltage (for example, a voltage of 800 V) based on the electric power from the quick charging device is applied between the power paths 62A and 61B, and the power storage units 20A and 20B are charged. In the charging mode in which the "first rapid charging" is performed, the operations of the first DC / DC converter 31 and the second DC / DC converters 32A and 32B may be stopped, or may be operated as needed.

When the above "second quick charge" is performed, for example, the control unit 48 controls the switches 51 and 52 to be in the on state and the switches 53 and 54 to be in the off state. When the switching unit 50 is switched in this way, a DC voltage (for example, a voltage of 400 V) supplied based on the power from the quick charging device is applied between the power paths 62A and 62B. In this state, for example, the control unit 48 causes the first DC / DC converter 31 to perform the second conversion operation. The control unit 48 boosts the DC voltage applied between the power lines 62A and 62B while the above "relatively low voltage" is applied between the power lines 62A and 62B, and the DC voltage between the power lines 62A and 61B ( For example, the operation of applying a voltage of 800 V) is performed by the first DC / DC converter 31. By such an operation, the power storage units 20A and 20B are charged. In the charging mode in which the "second quick charging" is performed, the operations of the second DC / DC converters 32A and 32B may be stopped, or may be operated as needed.

The control when a household commercial power source is connected to the vehicle 1 is as follows. When a commercial power source for home use is connected to the vehicle 1 and power based on this commercial power source is supplied to the vehicle-mounted charger 28, the vehicle-mounted charger 28 converts the power supplied from the commercial power source into electric power. A DC voltage is applied between the power lines 62A and 62B. At this time, the voltage applied by the vehicle-mounted charger 28 between the power paths 62A and 62B is about the same as the above-mentioned "relatively low voltage", and is equal to or less than the withstand voltage of the second DC / DC converters 32A and 32B. It is a voltage, for example, 400V. A known method may be used for the operation of the in-vehicle charger 28 to output a desired DC voltage based on the electric power from the commercial power source. In this way, when the vehicle-mounted charger 28 applies a DC voltage based on the external power to the second power path 62 when the power is supplied from the outside of the vehicle 1, the control unit 48 performs the second conversion operation. Let the first DC / DC converter 31 do this. The control unit 48 boosts the DC voltage applied between the power lines 62A and 62B while the above "relatively low voltage" is applied between the power lines 62A and 62B, and the DC voltage between the power lines 62A and 61B ( For example, the operation of applying a voltage of 800 V) is performed by the first DC / DC converter 31. By such an operation, the power storage units 20A and 20B are charged. In the charging mode in which charging is performed based on a commercial power source for home use, the operations of the second DC / DC converters 32A and 32B may be stopped or may be operated as needed.

Examples of the effects of the present disclosure are as follows. The conversion device 30 can realize bidirectional voltage conversion with the battery 20 side as the input side and the output side by the first DC / DC converter 31. On the other hand, the conversion device 30 can perform voltage conversion by each of the plurality of second DC / DC converters 32A and 32B. That is, the conversion device 30 can achieve both different voltage conversions. Moreover, each of the plurality of second DC / DC converters 32A and 32B is electrically connected to a part of the battery 20 so that a voltage within the withstand voltage range of the second DC / DC converters 32A and 32B is input. Therefore, the conversion device 30 can suppress the increase in withstand voltage of the device even when it is applied to a system in which the battery 20 outputs a high voltage.

In the conversion device 30, each connection target part is set as a different part in the battery 20, and each input voltage corresponding to the voltage across each in the plurality of connection target parts is applied to each of the plurality of second DC / DC converters 32A and 32B. Entered. Therefore, the conversion device 30 can connect the power supply sources of the plurality of second DC / DC converters 32A and 32B without concentrating them, and the respective second DC / DC converters 32A and 32B can be connected to the corresponding connection target portions. It can be operated independently based on the power from.

The connection portion 36 conducts the battery 20 and the high-voltage auxiliary machine 8 so as to input a voltage within the withstand voltage range of the high-voltage auxiliary machine 8 to the high-voltage auxiliary machine 8. Therefore, the conversion device 30 can be made conductive so as to input a voltage within the withstand voltage range of the high-voltage auxiliary machine 8 even if the battery 20 is configured to output a high voltage.

In the conversion system 4, a plurality of candidate parts to be power supply sources are predetermined in the battery 20, and the connection circuit 40 is energized so as to select a supply source for supplying power to the high-voltage auxiliary machine 8 from the plurality of candidate parts. It is configured to switch routes. Then, the connection control unit determines the power supply source selected by the connection circuit 40 based on the respective states of the plurality of candidate parts. Therefore, the conversion device 30 has a configuration in which a part of the battery 20 can be selected as a power supply source for the high-voltage auxiliary machine 8, and even if the battery 20 outputs a high voltage, the high-voltage auxiliary machine 8 is suppressed from increasing the withstand voltage. be able to. Moreover, since the conversion device 30 can select the power supply source for the high-voltage auxiliary machine 8 from the plurality of candidate parts, the power supply source can be switched as needed.

The connection circuit 40 has a configuration in which the power supply source for the high-voltage auxiliary machine 8 can be switched by turning on / off the plurality of switches 41, 42, 43, 44, and all of the plurality of switches 41, 42, 43, 44 are semiconductors. It is configured as a relay. Therefore, the connection circuit 40 has a long life, can be switched with good responsiveness, and is unlikely to be a noise source.

In the conversion device 30, the vehicle-mounted charger 28 applies a DC voltage based on the power from the outside to the second power path 62 when the power is supplied from the outside of the vehicle 1 on which the conversion device 30 is mounted. Then, the conversion control unit causes the first DC / DC converter 31 to perform the second conversion operation when the vehicle-mounted charger 28 applies a DC voltage to the second power path 62. That is, when power is supplied from the outside of the vehicle 1, the converter 30 applies a relatively low DC voltage to the second power path 62 by the vehicle-mounted charger 28, and applies this DC voltage to the first DC / DC converter 31. Can supply power for charging to the battery 20 by boosting the voltage.

The conversion device 30 does not use a dedicated boost converter to boost the DC voltage applied to the second power path 62 by the vehicle-mounted charger 28 when charging based on the power supply from the vehicle-mounted charger 28. The / DC converter 31 can also be used. Therefore, the conversion device 30 can simplify the device configuration. Further, the conversion device 30 can connect the vehicle-mounted charger 28 to the battery 20 via the first DC / DC converter 31, and the battery 20 can be connected to the second power path 62 through which the vehicle-mounted charger 28 can conduct. A voltage lower than the output voltage (for example, 400V) is applied. Therefore, the conversion device 30 can suppress the high pressure resistance of the in-vehicle charger 28.

In the conversion device 30, the rated voltage of each of the plurality of power storage units 20A and 20B to be connected is smaller than the withstand voltage of any of the plurality of second DC / DC converters 32A and 32B. Therefore, the conversion device 30 can more reliably prevent the second DC / DC converters 32A and 32B from being input with a voltage exceeding their respective withstand voltage.

<Other Embodiments>
The present disclosure is not limited to the embodiments described by the above description and drawings. For example, the features of the embodiments described above or below can be combined in any combination within a consistent range. Further, any of the features of the above-mentioned or later-described embodiments may be omitted unless it is clearly stated as essential. Further, the above-described embodiment may be modified as follows.

In the above embodiment, the number of power storage units configured as the battery unit and the number of the second voltage conversion units configured as the second DC / DC converter are the same, but the configuration of the conversion device is not limited to this configuration. The conversion device may differ in the number of battery units and the number of second DC / DC converters. For example, in the conversion device, three power storage units may be connected in series to form a battery, and two second DC / DC converters may be connected to each of the two power storage units.

In the above embodiment, the two storage units 20A and 20B are connected in series to form the battery 20, but the present invention is not limited to this example. In any of the configurations of the embodiment, three or more power storage units may be connected in series.

In the above embodiment, the two second DC / DC converters 32A and 32B are connected to each of the power storage units 20A and 20B, but the present invention is not limited to this example. In any of the configurations of the embodiment, three or more second voltage conversion units may be connected. For example, three second voltage conversion units may be connected to each of the three power storage units.

In the above embodiment, the two second DC / DC converters 32A and 32B are electrically connected to the common low-voltage battery 24 and connected so as to be able to supply power to the common load 7, but the present invention is limited to this example. Not done. In any of the configurations of the embodiment, as shown in FIG. 5, each of the plurality of second DC / DC converters 32A and 32B may be separately connected to each of the plurality of low voltage batteries 24A and 24B. .. Then, as shown in FIG. 5, each of the plurality of second DC / DC converters 32A and 32B is electrically connected to each of the plurality of loads 7A and 7B provided separately, and is connected to each of the loads 7A and 7B. On the other hand, the configuration may be such that electric power can be supplied separately. In the configuration of FIG. 5, the second DC / DC converter 32B is connected to the wirings 69A and 69B instead of the wirings 68A and 68B (FIG. 2). The conductive paths of the wirings 69A and 69B are electrically connected to both ends of the low-voltage battery 24B, and are electrically connected to both ends of the load 7B, respectively.

In the above embodiment, the circuit of FIG. 4 is used as a specific circuit of the second DC / DC converters 32A and 32B, but the present invention is not limited to this. The second DC / DC converters 32A and 32B may be any known DC / DC converter.

In the above embodiment, the case where each battery unit, the second DC / DC converters 32A and 32B, and the high-voltage auxiliary machine 8 have 400V specifications and a charging voltage of 800V or 400V is supplied from the quick charging device has been described. Not limited. The battery unit, the second DC / DC converters 32A and 32B, and the high-voltage auxiliary machine 8 may have specifications other than 400V. A charging voltage different from 800V or 400V may be supplied from the quick charging device.

In the above embodiment, the switches 41, 42, 43, 44 constituting the connection circuit 40 are semiconductor relays, but the switches 41, 42, 43, 44 may be electromagnetic relays. Further, the switches 51, 52, 53, 54, 18A and 18B may be semiconductor relays or electromagnetic relays.

In the above embodiment, the battery sensor 26 is not limited to this configuration in which the output voltage of each of the storage units 20A and 20B is detected. For example, the battery sensor 26 may be configured to detect SOC (State Of Charge) and SOH (State Of Health) of the power storage units 20A and 20B. The control unit 48 may switch the connection circuit 40 so that the power supply source of the high-voltage auxiliary machine 8 is selected from the power storage units 20A and 20B, whichever has the larger SOC. Alternatively, the control unit 48 may switch the connection circuit 40 so that the power supply source of the high-voltage auxiliary machine 8 is selected from the power storage units 20A and 20B, whichever has the larger SOH.

In the above embodiment, a configuration in which a DC voltage is applied from the vehicle-mounted charger 28 to the second power path 62 has been exemplified, but the configuration is not limited to this configuration. For example, the in-vehicle charger 28 is a DC voltage based on the electric power from the outside when electric power (for example, electric power from a commercial power source) is supplied to the electric power 1 from the outside of the vehicle 1 on which the conversion device 30 is mounted. May be applied to the first power path 61. In this case, the vehicle-mounted charger 28 may operate so as to apply a DC voltage having a relatively high voltage (for example, 800V) exceeding the withstand voltage of the second DC / DC converters 32A and 32B between the power paths 61A and 61B. .. Alternatively, the in-vehicle charger 28 stores a plurality of DC voltages within the withstand voltage range (for example, 400 V) of the second DC / DC converters 32A and 32B based on the electric power from the outside (for example, the electric power from the commercial power source). The configuration may be such that it can be applied to each of the parts 20A and 20B. In this case, the conversion device 30 includes a switching circuit capable of switching the connection destination (power supply destination) from the in-vehicle charger 28 to each of the plurality of power storage units 20A and 20B, and a switching control unit for controlling the switching circuit. It is desirable to have. In this case, the switching circuit may have the same configuration as the connection circuit 40 described above, for example. Specifically, the switching circuit is composed of a plurality of switches and a conductive path, and the power supply destination from the vehicle-mounted charger 28 is selectively selected from the plurality of power storage units 20A and 20B by switching the plurality of switches. It is good that it is configured to be. In this case, the control unit 48 may function as an example of the switching control unit, or a control device other than the control unit 48 may function as an example of the switching control unit. In either case, the switching control unit controls the switching circuit so that the connection destination (power supply destination) from the in-vehicle charger 28 is selectively selected from the plurality of power storage units 20A and 20B. It is good.

In the above-described embodiment, the case where the electric power conversion system is mounted on the vehicle has been described, but the present invention is not limited to this. The power conversion system may be used for applications other than in-vehicle applications.

It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is not limited to the embodiments disclosed here, but includes all modifications within the scope indicated by the claims or within the scope equivalent to the claims. Is intended.

1: Vehicle 4: Conversion system 6: Auxiliary system load 7: Load 7A: Load 7B: Load 8: High-voltage auxiliary machine (auxiliary machine)
10: Power supply system 12: Motor 14: Inverter 16: Capacitor 18: Switch unit 18A: Switch 18B: Switch 20: Battery 20A: Power storage unit (connection target part, candidate part)
20B: Power storage unit (connection target part, candidate part)
24: Low-voltage battery 24A: Low-voltage battery 24B: Low-voltage battery 26: Battery sensor 28: In-vehicle charger (charging device)
30: Converter 31: 1st DC / DC converter (1st voltage converter)
32A: 2nd DC / DCDC converter (2nd voltage converter)
32B: 2nd DC / DCDC converter (2nd voltage converter)
36: Connection part 40: Connection circuit 41: Switch (semiconductor relay)
42: Switch (semiconductor relay)
43: Switch (semiconductor relay)
44: Switch (semiconductor relay)
48: Control unit (connection control unit, conversion control unit)
50: Switching unit 51: Switch 52: Switch 53: Switch 54: Switch 58: Power line 59: Power line 61: First power line 61A: Power line 61B: Power line 62: Second power line 62A: Power line 62B: Power line 64A: Wiring 64B: Wiring 66A: Wiring 66B: Wiring 68A: Wiring 68B: Wiring 69A: Wiring 69B: Wiring 80: Capsule 82: DC / AC converter 82A: Switch element 82B: Switch element 82C: Switch element 82D: Switch element 84 : Transformer 86: Rectifier 86A: Switch element 86B: Switch element 86C: inductor 86D: Capsule

Claims (7)

A conversion device that converts the power supplied from a battery equipped with multiple power storage units.
A first voltage converter electrically connected to a first power path, which is a path for supplying power from the battery,
A plurality of second voltage converters electrically connected to the battery via a conductive path,
With
The first voltage conversion unit performs a first conversion operation of converting the voltage applied to the first power path into a voltage and applying an output voltage to the second power path, and a voltage applied to the second power path. The second conversion operation of converting and applying the output voltage to the first power path is performed.
A conversion device in which each of the plurality of second voltage conversion units is electrically connected to a part of the battery so that a voltage within the withstand voltage range of the second voltage conversion unit is input. A plurality of connection target parts are predetermined in the battery, and each connection target part is set as a different part in the battery.
Each of the plurality of second voltage conversion units is provided corresponding to each of the plurality of connection target portions.
The conversion device according to claim 1, wherein each input voltage corresponding to the voltage across each of the plurality of connection target portions is input to each of the plurality of second voltage conversion units. Provided with at least a partial intervening connection in the path between the battery and the auxiliary equipment.
The conversion device according to claim 1 or 2, wherein the connection portion conducts between the battery and the auxiliary machine so as to input a voltage within the withstand voltage range of the auxiliary machine to the auxiliary machine. .. The connection unit includes a connection circuit that constitutes an energization path between the battery and the auxiliary machine, and a connection control unit that controls the connection circuit.
A plurality of candidate parts to be power supply sources are determined in advance in the battery.
The connection circuit has a configuration in which the energization path is switched so that a supply source for supplying electric power to the auxiliary machine is selected from the plurality of candidate sites.
The conversion device according to claim 3, wherein the connection control unit determines a power supply source selected by the connection circuit based on each state of the plurality of candidate parts. The conversion device according to claim 4, wherein the connection circuit has a plurality of semiconductor relays, and selects a power supply source based on the on / off state of each of the plurality of semiconductor relays. Further, it is provided with a charging device and a conversion control unit.
When power is supplied from the outside of the vehicle on which the conversion device is mounted, the charging device applies a DC voltage based on the power from the outside to the second power path.
Any one of claims 1 to 5, wherein the conversion control unit causes the first voltage conversion unit to perform the second conversion operation when the charging device applies the DC voltage to the second power path. The converter according to the section. With the battery
The conversion device according to any one of claims 1 to 6, which converts the electric power supplied from the battery.
Conversion system including.

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