JP6588818B2 - Power distribution system and control method thereof - Google Patents

Description

  The present invention relates to a power distribution system and a control method thereof.

  Conventionally, for example, a high-voltage battery having a battery voltage of 42 V and a low-voltage battery having a battery voltage of 12 V are provided, and power from the high-voltage battery is supplied to electrical components having a required power of 250 W or more. In addition, a power distribution system that supplies power from a low-voltage battery has been proposed for electrical components whose required power is less than 250 W. In this power distribution system, the diameter of the high-voltage battery-side electric wire or the like can be reduced (see, for example, Patent Document 1).

JP 2002-109963 A

  Here, in a vehicle that uses a motor for traveling of the vehicle, such as an EV vehicle, two batteries are installed, a battery for traveling and a battery for auxiliary machines, and one DCDC converter is installed. Is preferred. However, since the battery for traveling is, for example, about 200V to 400V, when the battery for auxiliary equipment is provided with two batteries as in the power distribution system described in Patent Document 1, the battery for traveling is also used. In addition, at least three batteries and two DCDC converters are required. That is, a battery for driving (for high voltage) having a battery voltage of 200V to 400V, a battery for low voltage having a battery voltage of 12V, and a battery for medium voltage having a battery voltage of 42V (voltage is higher than that of the battery for driving). At least three batteries (referred to as low and medium voltage batteries) and two DCDC converters for making 12V and 48V. In addition, when the load of 42V can be limited, the 42V battery can be deleted, but even in that case, 42V can be reduced from a 12V battery or a traveling (high voltage) battery having a battery voltage of 200V to 400V using a dedicated DCDC converter. It is necessary to supply a DCDC converter separately from a DCDC converter for supplying a 12V battery from a traveling (high voltage) battery having a battery voltage of 200V to 400V, and two batteries are required for two batteries. A DC / DC converter is required, which increases the price.

  Here, the present inventor is considering mounting an auxiliary machine driven at a low pressure such as 12V and a heater driven at a medium pressure such as 24V on the vehicle. Since two batteries (for example, for 12V and 24V) are required for the machine, at least three batteries or two batteries and two DCDC converters including the traveling battery are required.

  The present invention has been made in order to solve such problems. The object of the present invention is to install two batteries and a DCDC converter mounted on a vehicle when a medium pressure drive load such as a heater is mounted. It is an object of the present invention to provide a power distribution system capable of appropriately driving both a heater and an auxiliary machine driven at a voltage lower than that of the heater, and a control method thereof.

  A power distribution system according to the present invention includes a traveling battery that is provided to drive a motor for traveling a vehicle and that can output a first voltage, a function that steps down the first voltage to obtain a second voltage, and the first A DC / DC converter having a function of stepping down one voltage to obtain an intermediate voltage between the first voltage and the second voltage; a general load driven by the DC / DC converter and the second voltage; A load path for connecting the DC / DC converter and a heater driven by the intermediate voltage, and a path for the heater that is driven by the intermediate voltage, First switch means provided on the downstream side of the branch point of the heater path and switchable between a conduction state and a cutoff state, and a second switch provided on the heater path and switchable between a conduction state and a cutoff state Means, The auxiliary load battery which is connected to the downstream side of the first switch means in the general load path and is a secondary battery capable of outputting the second voltage, the DC / DC converter, the first and first Control means capable of controlling two switch means, and when the control means drives both the heater and the general load, the control means controls the DC / DC converter to output the second voltage and A first control for setting the first switch means to a conductive state and the second switch means to a conductive state; controlling the DC / DC converter to output the intermediate voltage; and setting the first switch means to a cutoff state; The second control for holding the second switch means in a conductive state is executed alternately and repeatedly.

  In addition, a control method for a power distribution system according to the present invention includes a travel battery provided to drive a vehicle travel motor and capable of outputting a first voltage, and the first voltage is stepped down to a second voltage. A DC / DC converter having a function and a function of stepping down the first voltage to obtain an intermediate voltage between the first voltage and the second voltage, and the DC / DC converter and the second voltage. A general load path connecting a general load to be driven; a heater path branching from the general load path and connecting the DC / DC converter and the heater driven by the intermediate voltage; and the general load A first switch means provided downstream of the branch point of the heater path and switchable between a conductive state and a cut-off state, and a switch provided between the heater path and the conductive path and the cut-off state. Possible second A control method for a power distribution system comprising: switch means; and an auxiliary battery connected to a downstream side of the first load means in the general load path and capable of outputting the second voltage. A control step for controlling the DC / DC converter and the first and second switch means. In the control step, when both the heater and the general load are driven, the DC / DC A first control for controlling the converter to output the second voltage and setting the first switch means to the conductive state and the second switch means to the conductive state; and controlling the DC / DC converter to control the intermediate voltage. And the second control for alternately turning on the first switch means and keeping the second switch means in a conductive state. Characterized in that it run.

  According to the power distribution system of the present invention, when both the heater and the general load are driven, in the second control, the DC / DC converter is controlled to output the intermediate voltage, the first switch means is turned off, and the first switch means is turned off. 2 The switch means is turned on. For this reason, the intermediate voltage is supplied to the heater, and the heater can be driven at the intermediate voltage. At this time, since the auxiliary battery is connected downstream of the first switch means, the general load can be driven by the second voltage from the auxiliary battery.

  In the first control, the DC / DC converter is controlled to output the second voltage, and the first switch means and the second switch means are turned on. For this reason, the second voltage is supplied to the general load path, which is the path on the general load side, and the general load can be driven. At this time, although the intermediate voltage is not supplied to the heater and the second voltage is supplied, the heater does not rapidly decrease in temperature when the intermediate voltage is not supplied.

  Then, by repeating the first control and the second control alternately, the general load can be driven while heating the heater. Therefore, when the heater is mounted, the number of batteries mounted on the vehicle can be reduced, and both the heater and the auxiliary machine driven at a lower voltage than the heater can be appropriately driven.

  In the power distribution system according to the present invention, it is preferable that the period of the first control is shorter than the period of the second control.

  According to this power distribution system, since the period of the first control is shorter than the period of the second control, the period of the first control is lengthened to prevent the heater from being easily raised and easily lowered. The heater can be operated properly.

  Further, in the power distribution system according to the present invention, when the control means stops the supply of the intermediate voltage to the heater, the second switch at a timing when the output voltage of the DC / DC converter is the second voltage. It is preferred to turn the means off to a blocking state.

  According to this power distribution system, when the supply of the intermediate voltage to the heater is stopped, the second switch means is turned off at the timing when the output voltage of the DC / DC converter is the second voltage, so as to be cut off. For this reason, it is not necessary to use expensive switch means for arc countermeasures or the like.

  In the power distribution system according to the present invention, the heater includes a plurality of heaters, and the heater path has a plurality of branch paths each branched to a plurality of heaters, each connected to one of the plurality of heaters. 2 switch means is provided in each of the plurality of branch paths, and the control means is configured to drive one or more of the plurality of heaters and the general load when the plurality of heaters are driven. Of these, when the other heaters other than the one or more are further driven, it is preferable to turn on the second switch means for driving the other heaters during the first control so as to be in the conductive state.

  According to this power distribution system, when the other heater is driven, the second switch means for driving the other heater is turned on during the first control so as to be in a conductive state. For this reason, it is not necessary to use expensive switch means for arc countermeasures or the like.

  According to the present invention, when the heater is mounted, the number of batteries mounted on the vehicle and two DCDC converters can be appropriately driven for both the heater and the auxiliary device driven at a voltage lower than the heater. it can.

It is a circuit block diagram of the power distribution system which concerns on this embodiment. It is a state transition diagram of the power distribution system shown in FIG. It is a timing chart of the power distribution system shown in FIG.

  Hereinafter, the present invention will be described according to preferred embodiments. Note that the present invention is not limited to the embodiments described below, and can be appropriately changed without departing from the spirit of the present invention. Further, in the embodiment described below, there is a part where illustration or description of a part of the configuration is omitted, but details of the omitted technology are within a range in which there is no contradiction with the contents described below. Needless to say, known or well-known techniques are applied as appropriate.

  FIG. 1 is a circuit configuration diagram of a power distribution system 1 according to the present embodiment. As shown in FIG. 1, the power distribution system 1 according to the present embodiment includes a high-voltage power source (traveling battery) 10, a DC / DC converter 20, a general load path L <b> 1, a heater path L <b> 2, and a first switch unit. (First switch means) 40, second switch section (second switch means) 50, auxiliary battery (auxiliary battery) 60, and power supply controller (control means) 70 are provided.

  The high-voltage power supply 10 is a battery that can output a first voltage (for example, a voltage of 200 to 400 V), and a traveling battery that outputs the first voltage to a load driven by the first voltage such as a traveling motor. The high voltage power supply 10 is connected to a DC / DC converter 20.

  The DC / DC converter 20 has a function of reducing the first voltage to a second voltage (for example, 12V to 15V voltage). The DC / DC converter 20 also has a function of reducing the first voltage to an intermediate voltage (for example, 24 V) between the first voltage and the second voltage.

  The general load path L1 is a connection line that connects the DC / DC converter 20 and a general load driven by the second voltage. The heater path L2 is a connection line that branches from the general load path L1 and connects the DC / DC converter 20 to, for example, a heating wire heater H that is driven by an intermediate voltage. Here, in this embodiment, there are a plurality (two) of heaters H. The heater path L2 has a plurality (two) of branch paths L21 and L22 that are branched into a plurality (two) and are respectively connected to one of the plurality of heaters H.

  The first switch unit 40 is provided downstream of the branch point B of the heater path L2 in the general load path L1 (on the general load side and opposite to the high-voltage power supply 10). The switch means can be switched by. In the present embodiment, for example, an N-type MOSFET is used for the first switch unit 40, but the present invention is not limited to this, and a mechanical relay or another semiconductor relay may be used.

  Note that the first switch unit 40 and a part of the general load path L1 and the heater path L2 that are the peripheral part of the branch point B constitute a system-specific distributor 30.

  The 2nd switch part 50 is a switch means which is provided on the path | route L2 for heaters, and can be switched with a conduction | electrical_connection state and interruption | blocking state. Specifically, there are a plurality (two) of the second switch units 50, and each is provided on the branch paths L21 and L22. That is, the switch unit 51 is provided on the first branch path L21, and the switch unit 52 is provided on the second branch path L22. Moreover, although the mechanical relay is employ | adopted as each switch part 51 and 52, it is not restricted to this in particular, A semiconductor relay may be employ | adopted.

  The auxiliary battery 60 is a battery connected to the downstream side of the first switch unit 40 in the general load path L1 and capable of outputting the second voltage. The auxiliary battery 60 is composed of a rechargeable secondary battery.

  The power controller 70 is a control unit capable of controlling the DC / DC converter 20 and the first and second switch units 40 and 50. The power supply controller 70 receives, for example, an input signal H1SW for turning on or off the first heater H1, and an input signal H2SW for turning on or off the second heater H2. The power supply controller 70 receives the first voltage from the DC / DC converter 20 and outputs a control signal OUT that instructs whether the voltage is stepped down to the second voltage or the intermediate voltage. The DC / DC converter 20 performs a step-down operation so that the voltage indicated by the control signal OUT is obtained.

  In addition, the power supply controller 70 outputs a control signal V_NSW for turning on and off the first switch unit 40. The first switch unit 40 is switched between a conduction state and a cutoff state based on the control signal V_NSW. When the first switch unit 40 is in a conductive state, the DC / DC converter 20 and the general load are in a conductive state, and when the first switch unit 40 is in a cutoff state, the DC / DC converter 20 and the general load are in a cutoff state. . In the example shown in FIG. 1, since the first switch unit 40 is a MOSFET, the control signal V_NSW is a signal input to the gate electrode of the MOSFET.

  Furthermore, the power supply controller 70 outputs control signals H1CNT and H2CNT for turning on and off the second switch unit 50 (51, 52). The second switch unit 50 (51, 52) is switched between a conduction state and a cutoff state based on the control signals H1CNT and H2CNT. When the second switch unit 50 (51, 52) is turned on, the DC / DC converter 20 and the heater H are turned on, and when the second switch unit 50 (51, 52) is turned off, the DC / DC converter is turned on. 20 and the heater H are cut off. In the example shown in FIG. 1, since the second switch unit 50 (51, 52) is a mechanical relay, the control signals H1CNT and H2CNT are electric power signals supplied to coils constituting the mechanical relay.

  In such a power distribution system 1, the three states are changed according to the input states of the input signals H1SW and H2SW for turning on or off the first and second heaters H1 and H2.

  FIG. 2 is a state transition diagram of the power distribution system shown in FIG. In the state transition diagram of FIG. 2, the voltage value in the section from the DC / DC converter 20 to the branch point B is VOUT, and the voltage value downstream of the connection point between the auxiliary battery 60 and the general load path L1 is V_N. The voltage value in the section from the branch point B to the second switch unit 50 is denoted as V_H.

  As shown in FIG. 2, in the first state ST1, all the heaters H1, H2 are in an off state, and in the second state ST2, at least one of the heaters H1, H2 is in an on state, and a first control described later is executed. It is a state to do. The third state ST3 is a state in which at least one of the heaters H1, H2 is on, and a second control to be described later is executed. In all of the first to third states ST1 to ST3, at least one of the many general loads is driven.

  First, in the first state ST1, the power supply controller 70 controls the DC / DC converter 20 to step down to the second voltage by the control signal OUT. Further, the power supply controller 70 transmits a control signal V_NSW for making the first switch unit 40 conductive. At this time, the power supply controller 70 transmits the control signals H1CNT and H2CNT indicating that the switch units 51 and 52 are turned off without being turned on.

  In such a first state ST1, voltage value VOUT = voltage value V_N = voltage value V_H = second voltage.

  When the power controller 70 inputs the input signal H1SW for turning on the first heater H1 or the input signal H2SW for turning on the second heater H2 from the first state ST1, the power distribution system 1 Transition to the second state ST2 (see symbol SW1).

  In the second state ST2, the power supply controller 70 executes the first control. That is, the power supply controller 70 controls the DC / DC converter 20 to step down the input voltage to the second voltage according to the control signal OUT. Further, the power supply controller 70 transmits a control signal V_NSW for making the first switch unit 40 conductive. At this time, the power supply controller 70 also transmits control signals H1CNT and H2CNT indicating that the corresponding second switch unit 50 (51, 52) is in a conductive state. The power supply controller 70 transmits control signals H1CNT and H2CNT indicating that the second switch unit 50 (51, 52) that is not applicable is in a cut-off state.

  More specifically, when an input signal H1SW for turning on the first heater H1 is input, the power supply controller 70 transmits a control signal H1CNT that makes the corresponding second switch unit 51 conductive. On the other hand, when an input signal H2SW for turning on the second heater H2 is input, the power supply controller 70 transmits a control signal H2CNT that makes the corresponding second switch unit 52 conductive. In addition, the switch units 51 and 52 corresponding to the heaters H1 and H2 that do not receive the input signals H1SW and H2SW for turning on are turned off.

  In such a second state ST2, as in the first state ST1, the voltage value VOUT = the voltage value V_N = the voltage value V_H = the second voltage. Furthermore, the second state ST2 is maintained for the first period (specifically, 100 ms). And after 1st period progress, the power distribution system 1 transfers to 3rd state ST3 (refer code | symbol SW2).

  In the third state ST3, the power supply controller 70 executes the second control. That is, the power supply controller 70 controls the DC / DC converter 20 to step down to an intermediate voltage according to the control signal OUT. Further, the power supply controller 70 transmits a control signal V_NSW for setting the first switch unit 40 to the cutoff state. Further, similarly to the second state ST2, the power supply controller 70 transmits control signals H1CNT and H2CNT indicating that the corresponding switch units 51 and 52 are kept in the conductive state. The power supply controller 70 transmits control signals H1CNT and H2CNT indicating that the non-applicable switch units 51 and 52 are kept in the cutoff state.

  In such third state ST3, voltage value VOUT = voltage value V_H = intermediate voltage. Furthermore, the third state ST3 is maintained for the second period (specifically, 400 ms). And after 2nd period progress, the power distribution system 1 transfers to 2nd state ST2 again (refer code | symbol SW3).

  Here, in order to appropriately drive the heaters H1 and H2, it is preferable that the first period is shorter than the second period. This is because if the second period is too short, the heaters H1 and H2 are difficult to raise the temperature and easy to lower the temperature.

  Further, as is apparent from FIG. 2, when the input signals H1SW and H2SW for turning off both the heaters H1 and H2 are input, the power supply controller 70 shifts to the first state ST1 (see symbol SW4). . On the other hand, when the input signals H1SW and H2SW for turning off both the heaters H1 and H2 are not input, the power distribution system 1 does not shift to the first state ST1 but the second state ST2 and the third state ST3. The transition continues repeatedly (see symbols SW2 and SW3). That is, the power supply controller 70 executes control that repeats the first control and the second control.

  Next, operation | movement of the power distribution system 1 which concerns on this embodiment is demonstrated along a timing chart. FIG. 3 is a timing chart of the power distribution system shown in FIG. In FIG. 3, when both the first heater H1 (one or more examples of the plurality of heaters) and the general load among the plurality of heaters H are driven, the second heater H2 (the plurality of heaters) is driven. A case of driving one example of other heaters excluding one or more of the above will also be described.

  First, it is assumed that at time 0, input signals H1SW and H2SW for turning off both the first and second heaters H1 and H2 are input to the power supply controller 70. In this case, the power distribution system 1 is in the first state ST1, and the power supply controller 70 sets the output voltage of the DC / DC converter 20 to the second voltage. In addition, the first switch unit 40 is turned on and both the second switch units 51 and 52 are turned off to turn off both the first and second heaters H1 and H2.

  Thereafter, it is assumed that an input signal H1SW for turning on the first heater H1 is input at time t1. In this case, the power distribution system 1 transits to the second state ST2, and the power supply controller 70 sets the second switch unit 51 in a conductive state. Thereby, the first heater H1 is turned on. In this case, the output voltage of the DC / DC converter 20 is maintained at the second voltage, and the first switch unit 40 is also maintained in the conductive state. Further, the second switch unit 52 is also maintained in a cut-off state. In addition, since the 1st switch part 40 is a conduction | electrical_connection state, while the 2nd voltage is supplied to a general load, the auxiliary battery 60 will be charged.

  Next, at time t2 when the first period has elapsed from time t1, the power distribution system 1 transitions to the third state ST3. As a result, the power supply controller 70 controls the DC / DC converter 20 to set the output voltage to the intermediate voltage, and puts the first switch unit 40 in the cutoff state. Further, the power controller 70 holds the second switch unit 51 in the conductive state. Note that the power supply controller 70 also holds the second switch unit 52 in the disconnected state. As a result, the intermediate voltage is supplied to the first heater H1, and the voltage from the auxiliary battery 60 is supplied to the general load.

  Next, it is assumed that an input signal H2SW for turning on the second heater H2 is input at time t3. In this case, the power supply controller 70 does not immediately turn on the second switch unit 52 and waits for the standby time Tw to elapse.

  Then, at time t4 when the second period has elapsed from time t2, that is, at time t4 when the standby time Tw has elapsed from time t3, the power distribution system 1 transitions to the second state ST2. The power supply controller 70 turns on the second switch unit 52 at this timing. That is, the power supply controller 70 turns on the second switch unit 52 during the first control to make it conductive. At time t4, the output voltage of the DC / DC converter 20 becomes the second voltage, and the first switch unit 40 is turned on. Moreover, since the 1st switch part 40 is a conduction | electrical_connection state, while the 2nd voltage is supplied to a general load, the auxiliary battery 60 will be charged.

  Thereafter, at time t5 when the first period has elapsed from time t4, the power distribution system 1 transitions to the third state ST3. As a result, the power supply controller 70 controls the DC / DC converter 20 to set the output voltage to the intermediate voltage and put the first switch unit 40 in the cut-off state, similarly to the time t3. Further, the power supply controller 70 holds the second switch parts 51 and 52 in the conductive state. Thus, an intermediate voltage is supplied to the first and second heaters H1 and H2, and a voltage from the auxiliary battery 60 is supplied to the general load.

  Next, it is assumed that an input signal H2SW for turning off the second heater H2 is input at time t6. In this case, the power supply controller 70 does not immediately turn off the second switch unit 52 and waits for the elapse of the standby time Tw.

  Then, at time t7 when the second period has elapsed from time t5, that is, at time t7 when the standby time Tw has elapsed from time t6, the power distribution system 1 transitions to the second state ST2. The power supply controller 70 turns off the second switch unit 52 at this timing. At this time, the output voltage of the DC / DC converter 20 is the second voltage. In other words, the power supply controller 70 turns off the second switch unit 52 at the timing when the output voltage of the DC / DC converter 20 is the second voltage, and puts it into the cut-off state. At time t7, the first switch unit 40 is turned on. Moreover, since the 1st switch part 40 is a conduction | electrical_connection state, while the 2nd voltage is supplied to a general load, the auxiliary battery 60 will be charged.

  Next, at time t8 when the first period has elapsed from time t7, the power distribution system 1 transitions to the third state ST3. As a result, the power supply controller 70 controls the DC / DC converter 20 to set the output voltage to the intermediate voltage and put the first switch unit 40 in the cut-off state, similarly to the time t3. Further, the power controller 70 holds the second switch unit 51 in the conductive state. As a result, the intermediate voltage is supplied to the first heater H1, and the voltage from the auxiliary battery 60 is supplied to the general load.

  Next, it is assumed that an input signal H1SW for turning off the first heater H1 is input at time t9. In this case, the power supply controller 70 does not immediately turn off the second switch unit 51 and waits for the standby time Tw to elapse.

  Then, at time t10 when the second period has elapsed from time t8, that is, at time t10 when the standby time Tw has elapsed from time t9, the power distribution system 1 transitions to the first state ST1. The power supply controller 70 turns off the second switch unit 51 at this timing. At this time, the output voltage of the DC / DC converter 20 is the second voltage. That is, the power supply controller 70 turns off the second switch unit 51 at the timing when the output voltage of the DC / DC converter 20 is the second voltage, and puts it into a cut-off state. At time t10, the first switch unit 40 is turned on.

  Thus, according to the power distribution system 1 and the control method thereof according to the present embodiment, when both the heater H and the general load are driven, the intermediate voltage is controlled by controlling the DC / DC converter 20 in the second control. At the same time, the first switch unit 40 is turned off and the second switch unit 50 is turned on. For this reason, the intermediate voltage is supplied to the heater H, and the heater H can be driven at the intermediate voltage. At this time, since the auxiliary battery 60 is connected to the downstream side of the first switch unit H, the general load can be driven by the second voltage from the auxiliary battery 60.

  In the first control, the DC / DC converter 20 is controlled to output the second voltage, and the first switch unit 40 and the second switch unit 50 are made conductive. For this reason, the second voltage is supplied to the general load path L1, which is the path on the general load side, and the general load can be driven. At this time, the intermediate voltage is not supplied to the heater H and the second voltage is supplied, but the heater H does not rapidly decrease in temperature when the intermediate voltage is not supplied.

  The general load can be driven while heating the heater H by alternately repeating the first control and the second control. Therefore, when the heater H is mounted, the number of batteries mounted on the vehicle can be reduced, and both the heater H and the auxiliary machine (general load) driven at a voltage lower than the heater H can be appropriately driven.

  Furthermore, since the auxiliary battery 60 is a secondary battery and is provided on a path that can be charged during the first control, the auxiliary battery 60 is charged while the general load is driven while the heater H is heated. be able to.

  In addition, in the conventional power distribution system, the DC / DC converter 20 and the power supply controller 70 are often used, and the DC / DC converter 20 and the power supply controller 70 are improved in order to achieve the configuration according to the present embodiment. However, an additional distributor 30 for each system may be provided, and the number of configurations that increase is small. Furthermore, it is excellent in terms of cost and size as compared with an increase of one battery.

  In this embodiment, when the second voltage is 12 V, the intermediate voltage is 24 V, the first period is 100 ms, and the second period is 400 ms, the current for satisfying the target heater output is driven at 12 V. Therefore, even if the conductor cross-sectional area of the heater path L2 is reduced to 29%, the heat generation amount is the same. Since the weight of the electric wire is almost determined by the weight of the conductor, the weight of the electric wire can be reduced to 1/3 or less, and the amount of metal used for the conductor can be reduced to 29%, which can reduce the raw material cost.

  In addition, since the first period is shorter than the second period, it is possible to prevent the heater H from being easily raised and lowered easily due to the length of the first period, and to operate the heater H appropriately. .

  Further, when the supply of the intermediate voltage to the heater H is stopped, the second switch unit 50 is turned off at the timing when the output voltage of the DC / DC converter 20 is the second voltage, so as to be cut off. For this reason, it is not necessary to use expensive switch means for arc countermeasures or the like.

  Further, when driving another heater H (for example, when driving the second heater H2 while the first heater H1 is driven), to drive another heater H (for example, the second heater H2) during the first control. The second switch section 50 (52) is turned on to make it conductive. For this reason, it is not necessary to use expensive switch means for arc countermeasures or the like.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-described embodiments, and may be modified without departing from the spirit of the present invention, and may be appropriately changed within a possible range. These techniques may be combined.

  For example, in the present embodiment, the number of heaters H is two, but may be one, or may be three or more.

  Further, in the present embodiment, a signal from the power controller 70 is directly input to the first switch unit 40 and the second switch unit 50, and these are switched between a conduction state and a cutoff state. Between the power supply controller 70 and the first switch unit 40 and the second switch unit 50, other control units and circuits are interposed, and the first switch unit 40 and the second switch unit 50 are indirectly connected. It may be configured to be switched between a state and a cutoff state.

1: Power distribution system 10: High voltage power supply (battery for traveling)
20: DC / DC converter 30: Distributor by system 40: 1st switch part (1st switch means)
50, 51, 52: 2nd switch part (2nd switch means)
60: Auxiliary battery (auxiliary battery)
70: Power supply controller (control means)
B: Branch points H, H1, H2: Heater L1: General load path L2: Heater paths L21, L22: Branch paths ST1 to ST3: First to third states Tw: Standby time

Claims (5)

A travel battery provided to drive a vehicle travel motor and capable of outputting a first voltage;
A DC / DC converter having a function of stepping down the first voltage to a second voltage and a function of stepping down the first voltage to an intermediate voltage between the first voltage and the second voltage; ,
A general load path connecting the DC / DC converter and a general load driven by the second voltage;
A heater path that branches from the general load path and connects the DC / DC converter and a heater driven by the intermediate voltage;
A first switch means provided downstream of a branch point of the heater path in the general load path and switchable between a conduction state and a cutoff state;
A second switch means provided on the heater path and switchable between a conduction state and a cutoff state;
An auxiliary battery that is a secondary battery connected to the downstream side of the first switch means in the general load path and capable of outputting the second voltage;
Control means capable of controlling the DC / DC converter and the first and second switch means,
When both the heater and the general load are driven, the control means controls the DC / DC converter to output the second voltage, brings the first switch means into a conductive state, and the second switch means. And a second control for controlling the DC / DC converter to output the intermediate voltage, setting the first switch means in a shut-off state, and holding the second switch means in a conductive state. A power distribution system that executes control that alternately repeats control. The power distribution system according to claim 1, wherein a period of the first control is shorter than a period of the second control. When the supply of the intermediate voltage to the heater is stopped, the control means turns off the second switch means at a timing when the output voltage of the DC / DC converter is the second voltage, and puts it in a cut-off state. The power distribution system according to any one of claims 1 and 2. The heater is plural,
The heater path has a plurality of branch paths branched into a plurality and each connected to one of the plurality of heaters;
The second switch means is provided in each of the plurality of branch paths;
When the controller further drives one or more of the plurality of heaters and the general load, and further drives other heaters other than the one or more of the plurality of heaters, The power distribution system according to any one of claims 1 to 3, wherein the second switch means for driving the other heater is turned on during the first control to be in a conductive state. A running battery provided to drive a vehicle running motor and capable of outputting a first voltage; a function of stepping down the first voltage to obtain a second voltage; and stepping down the first voltage A DC / DC converter having a function of setting an intermediate voltage between one voltage and the second voltage; a general load path connecting the DC / DC converter and a general load driven by the second voltage; Branching from the general load path, connecting the DC / DC converter and the heater driven by the intermediate voltage, and a branch point of the heater path among the general load paths A first switch means provided on the downstream side and switchable between a conduction state and a cutoff state; a second switch means provided on the heater path and switchable between a conduction state and a cutoff state; and the general load path Of which 1 than switching means is connected to the downstream side, a control method of a power distribution system comprising a auxiliary battery is a secondary battery capable of outputting the second voltage,
A control step of controlling the DC / DC converter and the first and second switch means,
In the control step, when both the heater and the general load are driven, the DC / DC converter is controlled to output the second voltage, the first switch means is turned on, and the second switch means And a second control for controlling the DC / DC converter to output the intermediate voltage, setting the first switch means in a shut-off state, and holding the second switch means in a conductive state. A control method for a power distribution system, characterized by executing control that alternately repeats control.

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