JP2019047569A - Vehicular power distribution box - Google Patents

Abstract

To provide a vehicular power distribution box in which a component can be shared.SOLUTION: A vehicular power distribution box 1 includes a high-voltage battery 2, a plurality of semiconductor interrupters 15A to 15D that are disposed on respective electrical paths 21 between the semiconductor interrupters 15A to 15D and a plurality of high-voltage loads 5A to 5D for receiving power supply from the high-voltage battery 2 and that interrupt the electrical paths 21, and a control unit 16 that controls the plurality of semiconductor interrupters 15A to 15D. The semiconductor interrupters 15 each have a current detection unit 36 that detects the current value of current flowing through the electrical path 21, and a semiconductor switch 32 that interrupts the electrical path 21. The control unit 16 controls the semiconductor interrupters 15 to interrupt the electrical paths 21 on the basis of the respective interruption characteristics corresponding to the high-voltage loads 5. For each of the interruption characteristics, an interruption time t required for the semiconductor switch 32 to complete interruption of the electrical path 21 is set according to the current value of current flowing through the electrical path 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a distribution box for a vehicle.

  Circuit breakers for protecting high voltage circuits are mounted on vehicles such as electric vehicles (EVs), hybrid vehicles (HEVs), and plug-in hybrid vehicles (PHEVs) (see Patent Documents 1 and 2). Patent Document 1 discloses a high voltage distribution box in which a mechanical circuit breaker corresponding to a high voltage circuit is used. Patent Document 2 discloses an automotive power supply box in consideration of fuse maintenance.

JP 2003-250215 A JP, 2015-177589, A

  However, in the conventional circuit breaker, it is necessary to select fuses corresponding to various high voltage loads, or to design a new one for each vehicle, and there is room for improvement.

  An object of this invention is to provide the distribution box for vehicles which can achieve sharing of components.

  In order to achieve the above object, a distribution box for a vehicle according to the present invention is disposed in each electric path between a power supply and a plurality of loads supplied with electric power from the power supply, and a plurality of circuits for interrupting each electric path And a control unit for controlling the plurality of semiconductor circuit breakers, each of the semiconductor circuit breakers interrupting the electric circuit, and a current detection unit detecting a current value of the current flowing through the electric circuit. A semiconductor switch, and the control unit controls each of the semiconductor circuit breakers to shut off the electric path based on the interruption characteristic corresponding to each load, and each of the interruption characteristics is the electric path And a cut-off time until the electric switch is cut by the semiconductor switch is set in accordance with the current value of the current flowing through the switch.

  In the vehicular distribution box, preferably, the cutoff characteristic is set based on a load characteristic of the load and a wire smoke characteristic of a wire forming the electric path.

  In the vehicle distribution box, the semiconductor circuit breaker further includes a temperature detection unit that detects a temperature of the semiconductor switch, and a voltage detection unit that detects a voltage between two points on the electric path sandwiching the semiconductor switch. It is preferable that the control unit controls the electric path to be disconnected based on at least one of the temperature and the voltage regardless of the blocking characteristic.

  The vehicle distribution box further includes a main relay disposed on an electric path between the power supply and the plurality of semiconductor circuit breakers and opening / closing the electric path based on a control signal from the control unit, The semiconductor circuit breaker is preferably connected in parallel downstream of the main relay.

  ADVANTAGE OF THE INVENTION According to the distribution box for vehicles which concerns on this invention, it is effective in the ability to achieve sharing of components.

FIG. 1 is a block diagram showing a schematic configuration of a vehicular distribution box according to the embodiment. FIG. 2 is an exploded perspective view showing a schematic configuration of a vehicular distribution box according to the embodiment. FIG. 3 is a plan view of the vehicular distribution box according to the embodiment. FIG. 4 is an external view of the semiconductor circuit breaker according to the embodiment. FIG. 5 is a block diagram showing a schematic configuration of the semiconductor circuit breaker according to the embodiment. FIG. 6 is a diagram showing an example of the interrupting characteristics of the semiconductor circuit breaker according to the embodiment.

  Hereinafter, an embodiment of a vehicle distribution box according to the present invention will be described in detail with reference to the drawings. The present invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily conceived by those skilled in the art or those that are substantially the same. Moreover, various omissions, replacements, and changes can be made to the components in the following embodiments without departing from the scope of the invention. Furthermore, the configurations described below can be combined as appropriate.

[Embodiment]
FIG. 1 is a block diagram showing a schematic configuration of a vehicular distribution box according to the embodiment. FIG. 2 is an exploded perspective view showing a schematic configuration of a vehicular distribution box according to the embodiment. FIG. 3 is a plan view of the vehicular distribution box according to the embodiment. FIG. 4 is an external view of the semiconductor circuit breaker according to the embodiment. FIG. 5 is a block diagram showing a schematic configuration of the semiconductor circuit breaker according to the embodiment. FIG. 6 is a diagram showing an example of the interrupting characteristics of the semiconductor circuit breaker according to the embodiment. Here, the X direction in FIGS. 2 to 4 is the width direction of the vehicle distribution box in the present embodiment. The Y direction is the depth direction of the vehicle distribution box in the present embodiment, and is a direction orthogonal to the width direction. The Y1 direction is the front direction, and the Y2 direction is the back direction. The Z direction is the vertical direction of the vehicle distribution box in the present embodiment, and is a direction orthogonal to the width direction and the depth direction. The Z1 direction is upward, and the Z2 direction is downward.

  The vehicle distribution box 1 according to the present embodiment is, for example, an electric connection box mounted on a vehicle such as an electric vehicle (EV), a hybrid vehicle (HEV), and a plug-in hybrid vehicle (PHEV). As shown in FIG. 1, the vehicle distribution box 1 is disposed between the high voltage battery 2 and the inverter 3 and the plurality of high voltage loads 5A (5) to 5D (5), and the high voltage battery 2; Electrical connection and electrical disconnection between the inverter 3 and the like are performed. In the following description, the electrical connection is also referred to as “connection” and the electrical disconnection as “disconnection”.

  The high voltage battery 2 is a power supply which is mounted on the above-described vehicle and supplies power for driving the inverter 3 and the like. The high voltage battery 2 includes, for example, a battery pack to which a plurality of battery cells are connected, and supplies DC power. The high voltage battery 2 is not limited to the assembled battery as long as it can supply direct current power, and may have any form. The high voltage battery 2 is connected to the pair of power supply terminals 11A (11) and 11B (11) on the vehicle power distribution box 1 side. The pair of power supply terminals 11A and 11B are provided, for example, in one of the width directions (X directions) of the vehicular distribution box 1, as shown in FIGS. 2 and 3.

  The inverter 3 and the plurality of high voltage loads 5A to 5D are mounted on the above-described vehicle, and are operated by being supplied with DC power from the high voltage battery 2. The inverter 3 mainly converts a direct current from the high voltage battery 2 into an alternating current, and drives an alternating current motor for driving a vehicle by the alternating current. The inverter 3 is connected to a pair of inverter terminals 12A (12) and 12B (12) on the vehicle distribution box 1 side. The plurality of high voltage loads 5A to 5D are various devices such as, for example, an electric compressor, a DC / DC converter, an on-vehicle charger, and a PTC (Positive Temperature Coefficient) heater. Each high voltage load 5 is connected to a pair of load terminals 13 on the vehicle distribution box 1 side. Specifically, high voltage load 5A is connected to load terminals 13AA and 13AB, and high voltage load 5B is connected to load terminals 13BA and 13BB. High voltage load 5C is connected to load terminals 13CA and 13CB, and high voltage load 5D is connected to load terminals 13DA and 13DB. As shown in FIGS. 2 and 3, the load terminal 13 is provided, for example, in the back direction (Y2 direction) which is one of the depth directions (Y direction) orthogonal to the width direction of the vehicular distribution box 1.

  The vehicular distribution box 1 includes a pair of main relays 14A (14) and 14B (14), a plurality of semiconductor circuit breakers 15A (15) to 15D (15), and a control unit 16. The pair of main relays 14, the plurality of semiconductor circuit breakers 15, and the control unit 16 are housed in the housing 7 as shown in FIGS. 2 and 3. The housing 7 is composed of an upper cover 8 and a lower cover 9. Upper cover 8 and lower cover 9 are made of insulating synthetic resin or the like.

  The pair of main relays 14A and 14B are disposed on the electric path 4 (4A, 4B) between the high voltage battery 2 and the inverter 3, and open and close the electric path 4. Here, the open state of the main relays 14A and 14B means that the main relays 14A and 14B are in the off state and the electric path 4 is shut off. On the other hand, when the main relays 14A and 14B are in the closed state, it means that the main relays 14A and 14B are in the on state and the electric path 4 is energized. Each of the main relays 14A, 14B is configured of, for example, a bus bar, a semiconductor relay, or the like. The bus bar is a conductive member that constitutes a part of the electric path 4 and is made of, for example, a metal material such as a copper alloy. The semiconductor relay is for bidirectionally interrupting and energizing the electric paths 4A and 4B, and includes, for example, at least one power MOS-FET. Although the main relay 14 is configured to include the power MOS-FET, the present invention is not limited to this, and the main relay 14 may be configured by a so-called mechanical relay. The main relay 14A constitutes a part of the electric path 4A on the positive electrode side of the electric path 4, one of which is connected to the power supply terminal 11A and the other one of which is connected to the inverter terminal 12A. The main relay 14A is connected to the control unit 16, and shuts off or energizes the electric path 4A on the positive electrode side based on a control signal 23 from the control unit 16. The main relay 14B constitutes a part of the electric path 4B on the negative electrode side of the electric path 4, one of which is connected to the power supply terminal 11B and the other one of which is connected to the inverter terminal 12B. The main relay 14B is connected to the control unit 16, and shuts off or energizes the electric path 4B on the negative electrode side based on the control signal 23 from the control unit 16. The control signal 23 received by each main relay 14 may be the same or different.

  The plurality of semiconductor circuit breakers 15A to 15D are disposed on the respective electric paths 21 between the high voltage battery 2 and the plurality of high voltage loads 5A to 5D. Each electric path 21 is configured to branch from the electric path 4A between the main relay 14A and the inverter 3 and to be connected to each high voltage load 5. That is, the plurality of semiconductor circuit breakers 15A to 15D are connected in parallel downstream of the main relay 14A. Each semiconductor circuit breaker 15 protects an electric circuit including each high voltage load 5 from an overcurrent, and interrupts the electric path 21 according to the current value of the current flowing through the electric path 21. Here, the electric path 22 is configured to branch from the electric path 4 B of the main relay 14 B and the inverter 3 and to be connected to each high voltage load 5. Each of the semiconductor circuit breakers 15 constitutes a part of the electric path 21, one of which is connected to the electric path 4A, and the other one of which is connected to the load terminals 13AA, 13BA, 13CA, 13DA. Each semiconductor breaker 15 is mounted on, for example, the upper surface (direction Z1) of the control substrate 17 as shown in FIG. Each semiconductor circuit breaker 15 is connected to the control unit 16, and shuts off each electric path 21 based on each control signal 24 from the control unit 16. On the other hand, each semiconductor breaker 15 outputs temperature information, voltage information, and current information, which will be described later, to the control unit 16 as the breaker signal 25. As shown in FIG. 4, each semiconductor circuit breaker 15 includes a pair of terminal portions 30 and a plurality of control terminals 31. One of the pair of terminal portions 30 is connected to the load terminal 13 (including 13AA, 13BA, 13CA, 13DA), and the other is connected to the main relay 14A via the electric path 21. Each of the plurality of control terminals 31 is a pin terminal formed in an L shape in the front direction (Y1 direction), and is connected to the control unit 16. Each semiconductor breaker 15 is comprised including the semiconductor switch 32, the temperature detection part 33, the voltage detection part 34, the gate drive part 35, and the electric current detection part 36, as shown in FIG. That is, the plurality of semiconductor circuit breakers 15A to 15D have the same configuration regardless of the type of the high voltage load 5.

  The semiconductor switch 32 constitutes a part of the electric path 21 and blocks the electric path 21. The semiconductor switch 32 is formed of, for example, a power MOS-FET (Metal-Oxide-Semiconductor Field-Effect Transistor), which is a type of field effect transistor. In the semiconductor switch 32, the drain D is connected to the electric path 21 on the main relay 14A side, and the source S is connected to the electric path 21 on the load terminal 13 side. The gate G of the semiconductor switch 32 is connected to the gate drive unit 35, and cuts off the electric path 21 in accordance with the gate signal from the gate drive unit 35. Here, when the semiconductor switch 32 is in the OFF state, the electric path 21 is cut off, and when the semiconductor switch 32 is in the ON state, the electric path 21 is energized.

  The temperature detection unit 33 is a temperature sensor which is disposed in the vicinity of the semiconductor switch 32 and detects the temperature of the semiconductor switch 32. The temperature detection unit 33 includes, for example, a thermistor. The temperature detection unit 33 is connected to any one of the plurality of control terminals 31 and is connected to the control unit 16 via the control terminal 31. The temperature detection unit 33 constantly outputs the temperature of the semiconductor switch 32 to the control unit 16 as temperature information.

  The voltage detection unit 34 detects a voltage (potential difference) between two points on the electric path 21 sandwiching the semiconductor switch 32. As shown in FIG. 5, for example, between the source S and the drain D in the semiconductor switch 32, between two points on the electrical path 21 is not limited to this. The voltage detection unit 34 is connected to the pair of control terminals 31 among the plurality of control terminals 31, and is connected to the control unit 16 via the pair of control terminals 31. The voltage detection unit 34 constantly outputs a voltage value between two points on the circuit 21 as voltage information to the control unit 16.

  The gate drive unit 35 is connected to the control unit 16 and outputs a gate signal to the gate G of the semiconductor switch 32 based on the control signal 24 from the control unit 16. When the gate drive unit 35 outputs a gate signal, a drive voltage is applied to the gate G of the semiconductor switch 32, and the semiconductor switch 32 is turned on.

  The current detection unit 36 detects the current value of the current flowing through the electric path 21. That is, the current detection unit 36 detects an overcurrent flowing to the high voltage load 5. The current detection unit 36 is connected to any one of the plurality of control terminals 31 and is connected to the control unit 16 via the control terminal 31. The current detection unit 36 constantly outputs the current value of the current flowing through the electric path 21 as current information to the control unit 16.

  The control unit 16 mainly includes, for example, a microcomputer, and is mounted on the control board 17. The control unit 16 outputs a control signal 23 for controlling the driving of each main relay 14 to the main relays 14A and 14B. The control signal 23 causes, for example, energization and interruption of the electric paths 4A and 4B by the respective semiconductor circuit breakers 15. The control unit 16 is connected to the external ECU 6 and can output the control signal 23 based on, for example, a control signal input from the external ECU 6. Control unit 16 may be configured to output control signal 23 based on circuit breaker signal 25 received from semiconductor circuit breakers 15A to 15D.

  The control unit 16 further controls the plurality of semiconductor circuit breakers 15A to 15D. The control unit 16 controls each of the semiconductor circuit breakers 15 to cut off the electric path 21 based on the cut-off characteristic corresponding to each of the high voltage loads 5. This cutoff characteristic is set based on the load characteristic of the high voltage load 5 and the wire smoke characteristic of the wire leading to the high voltage load 5 as shown in FIG. In the cutoff characteristics shown in FIG. 6, the vertical axis is time t [sec], and the horizontal axis is current I [A]. The blocking characteristics are set in a region surrounded by the illustrated wire smoke characteristics and the load characteristics. That is, the cutoff characteristics in the present embodiment are set based on load characteristics of various high voltage loads 5 connected to the vehicle distribution box 1 and based on electric wire smoke characteristics of electric wires connected to the high voltage load 5. Is set. In the cutoff characteristics, the cutoff time t until the semiconductor switch 32 cuts off the electric path 21 is set in accordance with the current value of the current I flowing through the electric path 21. For example, in the illustrated blocking characteristics, if the current value of the current I is less than a [A], the blocking time t becomes shorter as the current value becomes larger, and if the current value of the current I becomes a [A] or more, The electric path 21 is immediately shut off. The cutoff characteristic is configured to be rewritable to the control unit 16. For example, the control unit 16 receives the cutoff characteristic corresponding to the high voltage load 5 newly connected to the load terminal 13 from the external ECU 6, and newly stores the cutoff characteristic in the memory in the microcomputer or the cutoff characteristic in the memory Rewrite

  Next, the interruption | blocking operation | movement of the power distribution box 1 for vehicles which concerns on this embodiment is demonstrated. The semiconductor breaker 15 is activated, for example, in response to a control signal from the control unit 16, detects the current value of the current flowing through the electric path 21 by the current detection unit 36, and outputs it to the control unit 16 as current information. The control unit 16 monitors the current I flowing through the electric path 21 based on the current information output from each of the semiconductor circuit breakers 15. The control unit 16 outputs the control signal 24 to the corresponding semiconductor circuit breaker 15 when it is determined that the current I is an overcurrent based on the cutoff characteristic corresponding to the high voltage load 5. In the semiconductor breaker 15, the gate drive unit 35 outputs a gate signal to the semiconductor switch 32 based on the control signal 24 output from the control unit 16, and the semiconductor switch 32 shuts off the electric path 21 according to the gate signal. Do.

  As described above, the vehicle distribution box 1 according to the present embodiment replaces the conventional mechanical circuit breaker with a semiconductor circuit breaker that can set the interrupting characteristics according to the various high voltage loads 5. As there is no need to manufacture a circuit breaker for each vehicle, it is possible to reduce the number of parts and to share (standardize) parts. In addition, it is possible to reduce the part number for managing the parts. In addition, as with mechanical circuit breakers, it is not necessary to take design margins sufficiently in consideration of errors in the interrupting characteristics and physical deterioration, so vehicle weight increase can be suppressed without using thicker wires. And can be easily installed. Moreover, it is not necessary to consider the maintainability of parts, and the degree of freedom in the layout design of the vehicle can be improved.

  Further, in the vehicle distribution box 1 according to the present embodiment, the cutoff characteristics are set based on load characteristics of various high voltage loads 5 connected to the vehicle distribution box 1, and electric wires connected to the high voltage loads 5. Is set based on the electric wire smoke characteristic of Thereby, it is possible to obtain the same interrupting characteristics as the conventional mechanical circuit breaker, and to individually set the interrupting characteristics by the control unit 16 according to the various high voltage loads 5 to be connected. Become. That is, it is possible to absorb the specification difference between the vehicles (for example, the type of the high voltage load 5 and the current value at the time of interruption), and it is possible to easily share the parts. In addition, by optimizing the cutoff characteristics, it is possible to reduce the size of the wires that constitute the high voltage circuit.

  Further, in the vehicle power distribution box 1 according to the present embodiment, the plurality of semiconductor circuit breakers 15A to 15D are connected in parallel downstream of the main relay 14A. Unlike the low voltage system (12V system) load, the number and type of high voltage loads mounted on vehicles such as EVs are limited, so one vehicle distribution box 1 supports the load specifications of the vehicle It is possible to

  In the above embodiment, the control unit 16 cuts off the electric path 21 based on at least one of the temperature detected by the temperature detection unit 33 and the voltage detected by the voltage detection unit 34 regardless of the shutoff characteristic. It may be controlled to Thereby, even when the semiconductor circuit breaker 15 fails, the electric circuit including each high voltage load 5 can be protected from the overcurrent.

  Further, in the above embodiment, the control unit 16 individually switches the plurality of semiconductor circuit breakers 15A to 15D from the disconnection state to the conduction state. As a result, it is not necessary to consider the maintainability of parts, and the degree of freedom in layout design of the vehicle can be improved.

  Further, in the above embodiment, the semiconductor switch 32 is configured by a power MOS-FET, but is not limited to this, and may be configured by a plurality of power MOS-FETs, or a transistor And IGBT (Insulated Gate Bipolar Transistor) etc. may be comprised.

  Moreover, although the said embodiment demonstrated the case where this invention was applied to the high voltage battery 2 or the high voltage circuit containing the high voltage load 3, it is not limited to this, You may apply to a low voltage circuit.

1 Vehicle Distribution Box 2 High Voltage Battery 3 Inverter 4, 4A, 4B, 21, 22 Electric Path 5, 5A, 5B, 5C, 5D High Voltage Load 6 External ECU
7 Case 8 Upper cover 9 Lower cover 11, 11A, 11B Power supply terminal 12, 12A, 12B Inverter terminal 13 Load terminal 14, 14A, 14B Main relay 15, 15A, 15B, 15C, 15D Semiconductor circuit breaker 16 Control part 17 Control board 23, 24 Control Signal 25 Circuit Breaker Signal 30 Terminal 31 Control Terminal 32 Semiconductor Switch 33 Temperature Detector 34 Voltage Detector 35 Gate Driver 36 Current Detector

Claims (4)

A plurality of semiconductor circuit breakers disposed in each of the electric paths between the power source and the plurality of loads supplied with power from the power source and interrupting the respective electric paths;
A control unit that controls a plurality of the semiconductor circuit breakers;
Equipped with
Each of the semiconductor circuit breakers
A current detection unit that detects the current value of the current flowing through the electric path;
A semiconductor switch that shuts off the electric path;
Have
The control unit
Controlling each of the semiconductor circuit breakers so as to interrupt the electric path based on the interrupting characteristic corresponding to each load;
Each said blocking characteristic is
According to the current value of the current flowing through the electric path, the interruption time until the electric path is interrupted by the semiconductor switch is set.
Vehicle distribution box characterized by The blocking characteristic is
It is set based on the load characteristic of the load and the wire smoke characteristic of the wire that constitutes the electric path,
The vehicle distribution box according to claim 1. The semiconductor circuit breaker further comprises:
A temperature detection unit that detects the temperature of the semiconductor switch;
A voltage detection unit that detects a voltage between two points on the electric path sandwiching the semiconductor switch;
Equipped with
The control unit
The electric path is controlled to be interrupted based on at least one of the temperature and the voltage regardless of the interruption characteristic.
The vehicle distribution box according to claim 1. It further comprises a main relay disposed on an electric path between the power supply and the plurality of semiconductor circuit breakers and opening and closing the electric path based on a control signal from the control unit.
The plurality of semiconductor circuit breakers
Connected in parallel downstream of the main relay,
The distribution box for vehicles of any one of Claims 1-3.

Images