JP2022149837A - Heating system of vehicle - Google Patents

Abstract

To avoid power shortage.SOLUTION: A heating system of a vehicle comprises: a PTC heater which is heated according to electric resistance characteristic of a positive temperature coefficient thermistor; and a controller which controls power supply to the PTC heater. The controller includes: one or more processors; and one or more memories which are connected with the processors. The processor cooperates with a program included in the memory to activate the PTC heater before starting up an engine and derives total power consumption of auxiliary machines including power consumption of the PTC heater when the engine is to be started up. When the total power consumption is a prescribed threshold value or more at the time of receiving a start request to start up the engine, the engine is started up after decreasing the electric current of the PTC heater.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heating device for a vehicle.

For example, Patent Literature 1 discloses a vehicle air conditioner capable of performing pre-air conditioning in which a heating operation is performed by a heat pump cycle before boarding. In such a vehicle air conditioner, the load of heating operation by the heat pump cycle during pre-air conditioning is reduced compared to normal air conditioning after boarding.

JP 2011-11686 A

A PTC (Positive Temperature Coefficient) heater is sometimes provided as a heat source for a vehicle heating device. The power consumption of the PTC heater is the largest when it is turned on, and decreases with the passage of time. Also, when starting the engine, the starter consumes a large amount of power. For these reasons, if the power consumption of the PTC heater is large when the engine is started, power shortage may occur.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vehicle heating device capable of avoiding power shortage.

In order to solve the above problems, the vehicle heating device of the present invention includes:
a PTC heater heated according to the electrical resistance characteristics of the positive temperature coefficient thermistor;
a control device for controlling power supply to the PTC heater;
with
The control device is
one or more processors;
one or more memories connected to the processor;
has
the processor cooperates with a program contained in the memory;
Turning on the PTC heater before starting the engine,
Deriving the total power consumption of the auxiliary equipment including the power consumption of the PTC heater when starting the engine,
If the total power consumption at the timing of receiving the start request for starting the engine is equal to or greater than a predetermined threshold, the current of the PTC heater is reduced before starting the engine.

According to the present invention, power shortage can be avoided.

FIG. 1 is a schematic diagram showing the configuration of a vehicle to which a heating device according to this embodiment is applied. FIG. 2 is a diagram showing an example of temporal transition of the temperature in the heating portion of the PTC heater. FIG. 3 is a diagram showing an example of temporal transition of power consumption in the heating portion of the PTC heater. FIG. 4 is a time chart explaining the operation of the control device. FIG. 5 is a flow chart for explaining the operation flow of the control device.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

FIG. 1 is a schematic diagram showing the configuration of a vehicle 1 to which a heating device 10 according to this embodiment is applied. Vehicle 1 is a hybrid vehicle having an engine 12 and a drive motor 14 . Vehicle 1 includes low-voltage battery 20 , low-voltage wiring 22 , starter 24 , high-voltage battery 26 and high-voltage wiring 28 .

Low-voltage battery 20 is, for example, a lead-acid battery. The voltage of the low voltage battery 20 is, for example, 12V. The low-voltage battery 20 is electrically connected to the low-voltage wiring 22 . The starter 24 is electrically connected to the low voltage system wiring 22 . The starter 24 starts the engine 12 under the control of the control device 42, which will be described later. Hereinafter, devices connected to the low-voltage wiring 22, such as the starter 24, may be called auxiliary devices.

High voltage battery 26 is, for example, a lithium ion battery. The voltage of the high-voltage battery 26 is, for example, 200 V, which is higher than the voltage of the low-voltage battery 20 and the voltage of the low-voltage wiring 22 . The high voltage battery 26 is electrically connected to the high voltage system wiring 28 . The drive motor 14 is electrically connected to high-voltage wiring 28 . The drive motor 14 is driven by power supplied from a high voltage battery 26 through a high voltage system wiring 28 .

The heating device 10 of the vehicle 1 is, for example, an in-vehicle air conditioner capable of sending warm air into the vehicle. The heating device 10 of the vehicle 1 includes a DCDC converter 30 , a blower fan 32 , a PTC heater 34 , a cooling water temperature detector 36 , a vehicle interior temperature detector 38 , an outside air temperature detector 40 and a controller 42 .

The DCDC converter 30 is located between the low voltage system wiring 22 and the high voltage system wiring 28 . The DCDC converter 30 is electrically connected to the low-voltage wiring 22 and electrically connected to the high-voltage wiring 28 . The DCDC converter 30 steps down the DC voltage of the high-voltage wiring 28 and supplies it to the low-voltage wiring 22 .

Blower fan 32 is electrically connected to low-voltage wiring 22 . The blower fan 32 supplies air to the heat exchanger of the in-vehicle air conditioner, and sends the air after heat exchange into the vehicle.

Cooling water for cooling the engine 12 is led to a heat exchanger of an in-vehicle air conditioner. When a sufficient amount of time has passed since the engine 12 was started, the cooling water of the engine 12 rises to about 80° C., for example. When the cooling water reaches such a temperature, it can be the heat source in the heat exchanger. That is, when the warm-up of the engine 12 is completed, the heat of the engine 12 transferred through the cooling water can be used for heating.

However, before the warm-up of the engine 12 is completed, the temperature of the cooling water of the engine 12 has not risen sufficiently. It may not work.

Therefore, in this embodiment, in addition to the cooling water of the engine 12 being led to the heat exchanger of the vehicle air conditioner, the PTC heater 34 is installed in the heat exchanger of the vehicle air conditioner. As will be described later, the PTC heater 34 is turned on before the warm-up of the engine 12 is completed, so that the heat of the PTC heater 34 performs the heating function.

The PTC heater 34 is electrically connected to the low-voltage wiring 22 . The PTC heater 34 has one or more heating portions 50 that generate heat according to the flowing current. In the example of FIG. 1, three heating units 50 are shown. The number of heating units 50 is not limited to three, and may be one, two, or four or more. In the PTC heater 34, when there are a plurality of heating units 50, the plurality of heating units 50 can be turned on independently. That is, in the PTC heater 34, the number of heating units 50 to be turned on can be arbitrarily changed.

The heating portion 50 of the PTC heater 34 is heated according to the electrical resistance characteristics of a positive temperature coefficient thermistor (Positive Temperature Coefficient Thermal Resistor).

FIG. 2 is a diagram showing an example of the temperature transition over time in the heating portion 50 of the PTC heater 34. As shown in FIG. FIG. 3 is a diagram showing an example of temporal transition of power consumption in the heating unit 50 of the PTC heater 34. As shown in FIG. It is assumed that the time axis of FIG. 2 and the time axis of FIG. 3 are common. 2 and 3, it is assumed that the heating unit 50 is turned on at timing T0.

At timing T0 when the heating unit 50 is turned on, the temperature of the heating unit 50 is assumed to be a temperature H0 lower than the Curie temperature H1 of the positive temperature coefficient thermistor. The Curie temperature H1 is an index determined by the material of the positive temperature coefficient thermistor, and can be arbitrarily set according to the composition of the material. The Curie temperature H1 indicates the temperature at which the electrical resistance sharply rises in the relationship of the electrical resistance to the temperature.

When the temperature of the heating part 50 is lower than the Curie temperature H1, the electric resistance value of the heating part 50 is low, and the current easily flows through the heating part 50 . Therefore, the heating unit 50 generates heat according to the flowing current, and as shown in FIG. 2, the temperature of the heating unit 50 rises from the temperature H0.

Further, when the temperature of the heating unit 50 is the temperature H0, the electric current easily flows as described above, so that the power consumption of the heating unit 50 increases as shown in FIG. Then, when the temperature of the heating unit 50 rises from the temperature H0, the electric resistance value of the heating unit 50 rises. Therefore, as shown in FIG. 3, the power consumption of the heating unit 50 decreases from the power consumption P0. go.

As shown in FIG. 2, when the temperature of the heating part 50 rises to the Curie temperature H1, the electric resistance value rises sharply, so that it becomes difficult for current to flow through the heating part 50 . Then, after the timing T1 when the Curie temperature H1 is reached, the temperature of the heating unit 50 is maintained at the Curie temperature H1.

Further, at the timing T1, as described above, it is difficult for the current to flow, so that the power consumption of the heating unit 50 is P1, which is smaller than the power consumption P0, as shown in FIG. Since the temperature of the heating unit 50 is maintained at the Curie temperature H1 after the timing T1, the power consumption of the heating unit 50 is maintained at the power consumption P1 as shown in FIG.

Thus, the power consumption of the heating unit 50 is the highest at timing T0 when it is turned on, and the power consumption decreases as time elapses. Also, the time from timing T0 to timing T1 depends on the temperature inside the vehicle or the temperature outside, but is, for example, several minutes.

Also, the power consumption of the entire PTC heater 34 is the sum of the power consumptions of the respective heating units 50 . Therefore, the power consumption of the PTC heater 34 increases as the number of the heating units 50 through which the current flows, that is, the number of the heating units 50 in the ON state increases. Hereinafter, turning on the PTC heater 34 means turning on at least one heating unit 50 among the heating units 50 in the OFF state. Turning off the PTC heater 34 indicates turning off one or more heating units 50 among the heating units 50 in the ON state.

Returning to FIG. 1 , the coolant temperature detector 36 is provided in the coolant flow path of the engine 12 . A cooling water temperature detector 36 detects the temperature of the cooling water of the engine 12 . The vehicle interior temperature detector 38 detects the temperature inside the vehicle. The outside temperature detection unit 40 detects the outside temperature.

Controller 42 includes one or more processors and one or more memories coupled to the processors. The memory includes a ROM storing programs and the like, and a RAM as a work area. The processor of the control device 42 cooperates with the programs contained in the memory to control the vehicle 1 as a whole. For example, the processor of controller 42 cooperates with a program contained in memory to control the power supply to PTC heater 34 .

For example, in winter, the driver may want to get into the vehicle 1 and have the heating function at the same timing as the engine 12 is started. In such a case, since warming up of the engine 12 is not completed, the PTC heater 34 is turned on. As described above, the power consumption of the heating portion 50 of the PTC heater 34 is the largest at the ON timing. Therefore, when the PTC heater 34 is turned on at the same timing as the start of the engine 12 , the maximum power consumption of the PTC heater 34 is superimposed on the power consumption of the starter 24 . As a result, power shortage may occur in the low-voltage wiring 22 .

Moreover, the power consumption of the starter 24 and the power consumption of the PTC heater 34 are larger than those of other auxiliary devices connected to the low-voltage wiring. Therefore, at the same timing as the start of the engine 12, the DCDC converter 30 may be caused to supply power from the high-voltage wiring 28 to the low-voltage wiring 22 in some cases. However, if the power consumption obtained by superimposing the maximum power consumption of the PTC heater 34 on the power consumption of the starter 24 is compensated for by the power through the DCDC converter 30, the size of the DCDC converter 30 must be increased.

Therefore, the control device 42 of the present embodiment turns on the PTC heater 34 before starting the engine 12 . In other words, the control device 42 turns on the PTC heater 34 when a predetermined heating start condition is satisfied while the engine 12 is stopped. That is, the control device 42 advances the power consumption timing for turning on the PTC heater 34 ahead of the power consumption timing for starting the engine 12 .

Specifically, when the controller 42 receives a command to turn on the PTC heater 34 from the remote communication device carried by the driver while the engine 12 is stopped, the controller 42 turns on the PTC heater 34 . Further, the control device 42 may turn on the PTC heater 34 when opening and closing of the driver's door is detected while the engine 12 is stopped. Further, the control device 42 may turn on the PTC heater 34 when a sensor provided on the driver's seat detects that the driver is seated while the engine 12 is stopped. Further, the control device 42 may turn on the PTC heater 34 when the driver is detected by an optical camera, a thermal camera, or the like while the engine 12 is stopped.

By turning on the PTC heater 34 before starting the engine 12, the timing at which the PTC heater 34 consumes the maximum power can be shifted from the timing at which the starter 24 consumes power. As a result, power shortage in the low-voltage wiring 22 due to superimposition of the maximum power consumption of the PTC heater 34 on the power consumption of the starter 24 can be avoided.

However, depending on the start timing of the engine 12, power shortage may not be avoided. For example, it is assumed that the seating of the driver is detected and the PTC heater 34 is turned on before the engine 12 is started. Here, it is assumed that the driver starts the engine 12 without delay after taking the seat. In such a case, the engine 12 may start before the power consumption of the heating unit 50 becomes sufficiently small. In this case, the power consumption of the PTC heater 34 combined with the power consumption of the starter 24 may still cause a power shortage in the low-voltage wiring 22 .

Therefore, the control device 42 of the present embodiment turns on the PTC heater 34 before starting the engine 12, and derives the total power consumption of the auxiliary equipment including the power consumption of the PTC heater when the engine is started. do. Then, if the total power consumption at the timing of receiving the start request to start the engine 12 is equal to or greater than a predetermined threshold, the control device 42 temporarily reduces the current of the PTC heater 34 and then starts the engine 12 .

FIG. 4 is a time chart for explaining the operation of the control device 42. As shown in FIG. In the example of FIG. 4, at timing T10, it is assumed that the engine 12 is off and a predetermined heating start condition is satisfied. As a result, the controller 42 turns on the PTC heater 34 at timing T10. At timing T10 when the PTC heater 34 is turned on, power is not consumed by the starter 24, so power shortage due to the PTC heater 34 being turned on can be avoided.

In addition, the controller 42 starts operating the DCDC converter 30 in parallel with turning on the PTC heater 34 . Then, the current flowing through the low-voltage wiring 22 through the DCDC converter 30, that is, the current of the DCDC converter 30 rises from the reference value i0 to the first predetermined value i1.

Assume that the controller 42 receives a request to start the engine 12 at timing T11 after timing T10. The engine start flag in FIG. 4 is turned on from the reception of the start request until the start operation of the engine 12 is completed.

In FIG. 4, it is assumed that the total power consumption of the accessories is equal to or greater than a predetermined value at timing T11 when the start request is received. The controller 42 turns off the PTC heater 34 at timing T11 to temporarily reduce the current of the PTC heater 34 . At this time, the control device 42 may temporarily reduce the current of the PTC heater 34 , and may turn off part of the heating unit 50 instead of turning off the entire heating unit 50 . Note that when the total power consumption of the auxiliary equipment is less than the predetermined value at the timing T11 when the start request is received, the control device 42 does not turn off the heating units 50, and the number of heating units 50 to be turned on. may be maintained.

When temporarily decreasing the current of the PTC heater 34 at the timing T11, the control device 42 continues the operation of the DCDC converter 30 and maintains the current of the DCDC converter 30 at the first predetermined value i1.

At timing T12 after timing T11, the control device 42 causes the starter 24 to start the engine 12 . At this time, since the current of the PTC heater 34 is temporarily reduced, the power consumption of the PTC heater 34 is suppressed. Therefore, even if the starter 24 consumes power, power shortage in the low-voltage wiring 22 can be avoided. When the engine 12 is turned on, the heat of the engine 12 increases the temperature of the cooling water.

Assume that the starting operation of the engine 12 is completed at timing T13 after timing T12. Then, the controller 42 turns on the PTC heater 34 to increase the current of the PTC heater 34 . At this time, the control device 42 turns on the heating unit 50 that has been temporarily turned off. Since the time from timing T11 to timing T13 is short, the temperature drop of the PTC heater 34 during this time is small. Also, since the PTC heater 34 is turned on again, the temperature of the PTC heater 34 can be maintained at the temperature required for heating until the engine 12 is completely warmed up.

For example, assume that the blower fan 32 is turned on at timing T14 after timing T13. A blower fan 32 supplies air to a heat exchanger in which a heated PTC heater 34 is installed. Therefore, the air is warmed by the heat of the PTC heater 34, and the warmed air is sent into the vehicle.

Assume that at timing T15 after timing T14, the temperature of the cooling water reaches a predetermined temperature H10 indicating that the warm-up of the engine 12 is completed. Then, the controller 42 turns off the PTC heater 34 . Since the warm-up is completed, even if the PTC heater 34 is turned off, the air is warmed by the heat of the engine 12 transferred to the cooling water, and the warmed air is sent into the vehicle.

When the PTC heater 34 is turned off, the controller 42 reduces the current of the DCDC converter 30 to a second predetermined value i2 that is less than or equal to the first predetermined value i1. This is because turning off the PTC heater 34 reduces the power required in the low-voltage wiring 22 .

FIG. 5 is a flow chart for explaining the operation flow of the control device 42. As shown in FIG. The controller 42 executes a series of processes in FIG. 5 when a predetermined heating start condition is satisfied.

The control device 42 first acquires the current SOC (State Of Charge) of the high-voltage battery 26, and determines whether the current SOC is equal to or higher than a predetermined value (S10). The predetermined value is, for example, 10%, but it is not limited to the exemplified value and can be set arbitrarily.

If the current SOC is less than the predetermined value (NO in S10), control device 42 terminates the series of processes. In this case, since the SOC of the high-voltage battery 26 is low, power is not supplied from the high-voltage wiring 28 to the low-voltage wiring 22 and the PTC heater 34 is not turned on. Note that the control device 42 may notify the driver that the current SOC is less than a predetermined value and cause the driver to charge the high-voltage battery 26 .

If the current SOC is equal to or higher than the predetermined value (YES in S10), the control device 42 acquires the temperature inside the vehicle from the vehicle interior temperature detection section 38 and acquires the outside temperature from the outside temperature detection section 40 (S11).

Next, the control device 42 derives the number of heating units 50 to be turned on based on the temperature inside the vehicle and the outside temperature (S12). For example, the memory of the control device 42 stores in advance a map in which the temperature inside the vehicle, the outside temperature, and the number of heating units 50 are associated. This map is set, for example, so that the number of heating units 50 increases as each temperature decreases. The control device 42 refers to this map to derive the number of heating units 50 to be turned on.

Next, the control device 42 starts the operation of the DCDC converter 30 (S13). In parallel with the start of the operation of the DCDC converter 30, the control device 42 turns on the heating units 50 of the PTC heater 34 by the number derived in step S12 (S14).

Next, the control device 42 derives the total power consumption of the accessories (S15). For example, the memory of the control device 42 stores in advance a representative value of the standby power consumption of all the accessories before starting the engine 12 and a representative value of the power consumption of the starter 24 when the engine 12 is started. there is The control device 42 obtains the current value of the PTC heater 34 and derives the current power consumption of the PTC heater 34 from the obtained current value. The controller 42 sums the representative value of the standby power, the representative value of the power consumption of the starter 24 and the current power consumption of the PTC heater 34 to derive the total power consumption.

Next, the controller 42 determines whether or not a request to start the engine 12 has been received (S16). If a request to start engine 12 has not been received (NO in S16), control device 42 returns to step S15 and repeats derivation of total power consumption until a request to start engine 12 is received. Note that if the current SOC becomes equal to or less than a predetermined value before receiving the request to start the engine 12 , the control device 42 may turn off the PTC heater 34 and stop the operation of the DCDC converter 30 .

If a request to start engine 12 has been received (YES in S16), control device 42 determines whether or not the total power consumption derived in step S15 is equal to or greater than a predetermined threshold (S17). The predetermined threshold is set based on the step-down capability of the DCDC converter 30, for example. For example, the predetermined threshold is set to a larger value as the step-down capability of the DCDC converter 30 is higher.

If the total power consumption is equal to or greater than the predetermined threshold (YES in S17), the control device 42 determines the number of heating units 50 to be cut off among the heating units 50 to which current is flowing, that is, the number of heating units 50 to be turned off. A number is derived (S20). For example, the memory of the control device 42 stores in advance a map in which the difference value between the total power consumption and the predetermined threshold is associated with the number of the heating units 50 to be turned off. This map is set such that the greater the difference between the total power consumption and the predetermined threshold value, the greater the number of heating units 50 that are turned off. The control device 42 derives the difference value between the current total power consumption and the predetermined threshold value, applies it to this map, and derives the number of the heating units 50 to be turned off.

Next, the control device 42 turns off the heating portion 50 of the PTC heater 34 by the number derived in step S20 to reduce the current of the PTC heater 34 (S21). As a result, power consumption in the low-voltage wiring 22 is reduced by the amount that the heating unit 50 is turned off, and power shortage in the low-voltage wiring 22 can be avoided even when the engine 12 is started by the starter 24 . In the memory of the control device 42 , the priority of the heating units 50 to be turned on may be set among the plurality of heating units 50 . The control device 42 may turn off the number of heating units 50 derived in step S20 in descending order of priority among the heating units 50 in the ON state.

Next, the control device 42 transmits a starting command for starting the engine 12 to the starter 24 (S22). As a result, the starter 24 that has received the start command starts the engine 12 .

Next, the control device 42 determines whether or not the starting operation of the engine 12 has been completed (S23). If the starting operation of the engine 12 has not been completed (NO in S23), the control device 42 waits until the starting operation of the engine 12 is completed.

When the starting operation of the engine 12 is completed (YES in S23), the control device 42 turns on the heating unit 50 that was turned off in step S21, thereby increasing the current of the PTC heater 34 (S24). Proceed to processing. In other words, the control device 42 returns the power consumption of the PTC heater 34 to the power consumption immediately before turning off the heating unit 50 by supplying the heating unit 50 with the current cut off in step S21. The starter 24 does not consume electric power after the starting operation of the engine 12 is completed. Therefore, even if the power consumption of the PTC heater 34 is restored after the starting operation of the engine 12 is completed, power shortage in the low-voltage wiring 22 can be avoided.

In step S17, when the total power consumption is less than the predetermined threshold (NO in S17), the control device 42 transmits a start command to the starter 24 (S26), and proceeds to the process of step S30. This is because the total power consumption is smaller than the predetermined threshold, so that even if the engine 12 is started, power shortage in the low-voltage wiring 22 does not occur.

In step S30, the control device 42 determines whether or not the warm-up is completed (S30). Specifically, the control device 42 acquires the temperature of the coolant from the coolant temperature detector 36 . If the temperature of the cooling water is equal to or higher than the predetermined temperature, the control device 42 determines that the warm-up is complete.

If the warm-up is not completed (NO in S30), the controller 42 waits until the warm-up is completed. When warming-up is completed (YES in S30), the control device 42 turns off all the heating units 50 of the PTC heater 34 (S31). Then, the control device 42 reduces the current of the DCDC converter 30 to a second predetermined value i2 that is equal to or less than the first predetermined value i1 (S32), and ends the series of processes.

As described above, in the heating device 10 of the vehicle 1 of this embodiment, the PTC heater 34 is turned on before the engine 12 is started. Then, in the heating device 10 of the vehicle 1 of the present embodiment, if the total power consumption of the accessories at the timing of receiving the start request of the engine 12 is equal to or greater than a predetermined threshold value, the current of the PTC heater 34 is temporarily reduced. , the engine 12 is started.

Therefore, according to the heating device 10 of the vehicle 1 of the present embodiment, power shortage in the low-voltage wiring 22 can be avoided, and the heating function can be exhibited.

In addition, in the heating device 10 of the vehicle 1 of the present embodiment, the power consumption peak in the low-voltage wiring 22 is suppressed, so that the size of the DCDC converter 30 that supplies power to the low-voltage wiring 22 is prevented from increasing. can do.

In addition, the heating device 10 of the vehicle 1 of the above-described embodiment was an in-vehicle air conditioner. However, the heating device 10 is not limited to an in-vehicle air conditioner. For example, the heating device 10 may be a seat heater or the like in which the PTC heater 34 is installed inside the seat to heat the seat.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope of the claims, and it should be understood that these also belong to the technical scope of the present invention. be done.

1 Vehicle 10 Heating Device 12 Engine 22 Low Voltage System Wiring 24 Starter 26 High Voltage Battery 28 High Voltage System Wiring 30 DCDC Converter 34 PTC Heater 42 Controller 50 Heating Unit

Claims (4)

a PTC heater heated according to the electrical resistance characteristics of the positive temperature coefficient thermistor;
a control device for controlling power supply to the PTC heater;
with
The control device is
one or more processors;
one or more memories connected to the processor;
has
the processor cooperates with a program contained in the memory;
Turning on the PTC heater before starting the engine,
Deriving the total power consumption of the auxiliary equipment including the power consumption of the PTC heater when starting the engine,
If the total power consumption at the timing of receiving the start request for starting the engine is equal to or greater than a predetermined threshold, the current of the PTC heater is reduced and then the engine is started.
Vehicle heating system. The processor increases the decreased current of the PTC heater after completion of the engine starting operation.
The heating device for a vehicle according to claim 1. The PTC heater has one or more heating units that generate heat according to the flowing current,
The processor
Before starting the engine, the PTC heater is turned on by passing a current through one or more of the one or more heating units,
If the total power consumption at the timing at which the start request is received is equal to or greater than a predetermined threshold, current is cut off to any one or more of the heating units through which the current is flowing. decrease the current of the PTC heater;
The heating device for a vehicle according to claim 1 or 2. Connected to a low-voltage wiring electrically connected to a starter for starting the engine and a high-voltage wiring electrically connected to a high-voltage battery having a voltage higher than the voltage of the low-voltage wiring, A DCDC converter that steps down the DC voltage of the high voltage system wiring and supplies it to the low voltage system wiring,
The PTC heater is electrically connected to the low-voltage wiring,
The processor turns on the PTC heater before starting the engine, and starts operating the DCDC converter.
A heating device for a vehicle according to any one of claims 1 to 3.

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