JP7629327B2 - Vehicle heating system - Google Patents

Description

The present invention relates to a vehicle heating device.

For example, Patent Document 1 discloses a vehicle air conditioner capable of performing pre-air conditioning, which performs heating operation using a heat pump cycle before the vehicle enters the vehicle. In such a vehicle air conditioner, the load of heating operation using a heat pump cycle during pre-air conditioning is reduced compared to normal air conditioning after the vehicle enters the vehicle.

JP 2011-11686 A

A PTC (Positive Temperature Coefficient) heater is sometimes installed as a heat source for the vehicle's heating system. The power consumption of a PTC heater is greatest when it is turned on, and decreases over time. Also, when the engine is started, the power consumption of the starter is large. For these reasons, if the power consumption of the PTC heater is large when the engine is started, there is a risk of a power shortage occurring.

The present invention aims to provide a vehicle heating device that can avoid power shortages.

In order to solve the above problems, a vehicle heating device according to the present invention comprises:
a PTC heater that is heated according to the electrical resistance characteristics of a positive temperature coefficient thermistor;
A control device that controls the supply of power to the PTC heater;
a DC-DC converter connected to a low-voltage system wiring to which a starter for starting an engine is electrically connected and to a high-voltage system wiring to which a high-voltage battery having a voltage higher than that of the low-voltage system wiring is electrically connected, the DC-DC converter stepping down a DC voltage of the high-voltage system wiring and supplying the DC voltage to the low-voltage system wiring;
Equipped with
the PTC heater is electrically connected to the low-voltage wiring;
The control device includes:
one or more processors;
one or more memories coupled to the processor;
having
The processor operates in conjunction with a program contained in the memory;
turning on the PTC heater and starting operation of the DCDC converter before starting the engine;
A total power consumption of the auxiliary devices including the power consumption of the PTC heater when the engine is started is derived;
If the total power consumption at the time when a start request to start the engine is received is equal to or greater than a predetermined threshold, the current of the PTC heater is reduced and then the engine is started.

The present invention makes it possible to avoid power shortages.

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 the change in temperature over time in the heating portion of the PTC heater. FIG. 3 is a diagram showing an example of the change over time in power consumption in the heating portion of the PTC heater. FIG. 4 is a time chart illustrating the operation of the control device. FIG. 5 is a flowchart illustrating the flow of operations of the control device.

The following describes in detail an embodiment of the present invention with reference to the attached drawings. The dimensions, materials, and other specific values shown in the embodiment are merely examples to facilitate understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements that have substantially the same function and configuration are given the same reference numerals to avoid duplicated explanations, and elements that are not directly related to the present invention are not illustrated.

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. The vehicle 1 is a hybrid vehicle equipped with an engine 12 and a drive motor 14. The vehicle 1 is equipped with a low-voltage battery 20, low-voltage system wiring 22, a starter 24, a high-voltage battery 26, and high-voltage system wiring 28.

The low-voltage battery 20 is, for example, a lead-acid battery. The voltage of the low-voltage battery 20 is, for example, 12 V. The low-voltage battery 20 is electrically connected to the low-voltage system 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 a control device 42 described below. Hereinafter, devices connected to the low-voltage system wiring 22, such as the starter 24, may be referred to as accessories.

The 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 system 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 the high-voltage system wiring 28. The drive motor 14 is driven by power supplied from the high-voltage battery 26 through the high-voltage system wiring 28.

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

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

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

The coolant that cools the engine 12 is guided to a heat exchanger in the vehicle air conditioning system. After a sufficient amount of time has passed since the engine 12 was started, the temperature of the engine 12 coolant will rise to, for example, about 80°C. When the coolant reaches that temperature, it can be used as a heat source in the heat exchanger. In other words, once the engine 12 has finished warming up, heating can be performed using the heat of the engine 12 that is transferred through the coolant.

However, before the engine 12 has finished warming up, the temperature of the engine 12's cooling water has not risen sufficiently, so even if the blower fan 32 is turned on, the air may not be warmed by the heat exchanger, and the heating function may not be achieved.

Therefore, in this embodiment, the engine 12 cooling water is led to the heat exchanger of the vehicle air conditioner, and the PTC heater 34 is installed in the heat exchanger of the vehicle air conditioner. Then, as will be described later, before the engine 12 has finished warming up, the PTC heater 34 is turned on to provide a heating function using the heat of the PTC heater 34.

The PTC heater 34 is electrically connected to the low-voltage wiring 22. The PTC heater 34 has one or more heating sections 50 that generate heat according to the current flowing therethrough. In the example of FIG. 1, three heating sections 50 are shown. Note that the number of heating sections 50 is not limited to three, and there may be one, two, or four or more heating sections. In the case where the PTC heater 34 has multiple heating sections 50, each of the multiple heating sections 50 can be turned on independently. In other words, in the PTC heater 34, the number of heating sections 50 that are turned on can be changed as desired.

The heating portion 50 of the PTC heater 34 is heated according to the electrical resistance characteristics of a positive temperature coefficient thermal resistor.

Figure 2 is a diagram showing an example of the change over time in temperature in the heating section 50 of the PTC heater 34. Figure 3 is a diagram showing an example of the change over time in power consumption in the heating section 50 of the PTC heater 34. The time axis in Figure 2 and the time axis in Figure 3 are assumed to be the same. In Figures 2 and 3, it is assumed that the heating section 50 is turned on at timing T0.

At the timing T0 when the heating unit 50 is turned on, the temperature of the heating unit 50 is H0, which is 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 set arbitrarily depending on the composition of the material. The Curie temperature H1 indicates the temperature at which the electrical resistance value changes suddenly in the relationship between temperature and electrical resistance value.

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

When the temperature of the heating unit 50 is temperature H0, current flows easily as described above, and so the power consumption of the heating unit 50 becomes large, as shown in FIG. 3, as power consumption P0. When the temperature of the heating unit 50 rises from temperature H0, the electrical resistance value of the heating unit 50 increases, and so the power consumption of the heating unit 50 decreases from power consumption P0, as shown in FIG. 3.

As shown in FIG. 2, when the temperature of the heating unit 50 rises to the Curie temperature H1, the electrical resistance value rises rapidly, making it difficult for a current to flow through the heating unit 50. Then, after timing T1 when the Curie temperature H1 is reached, the temperature of the heating unit 50 is maintained at the Curie temperature H1.

At timing T1, as described above, it becomes difficult for current to flow, and therefore, as shown in FIG. 3, the power consumption of the heating unit 50 becomes power consumption P1, which is smaller than power consumption P0. Then, after timing T1, the temperature of the heating unit 50 is maintained at the Curie temperature H1, and therefore, as shown in FIG. 3, the power consumption of the heating unit 50 is maintained at power consumption P1.

In this way, the power consumption of the heating unit 50 is the highest when it is turned on at time T0, and decreases as time passes. The time from time T0 to time T1 depends on the temperature inside the vehicle or the outside temperature, but is, for example, about several minutes.

The total power consumption of the PTC heater 34 is the sum of the power consumption of each heating unit 50. Therefore, the greater the number of heating units 50 passing current, i.e., the greater the number of heating units 50 in the ON state, the greater the power consumption of the PTC heater 34. Hereinafter, turning on the PTC heater 34 refers to turning on one or more of the heating units 50 in the OFF state. Turning off the PTC heater 34 refers to turning off one or more of the heating units 50 in the ON state.

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

The control device 42 includes one or more processors and one or more memories connected to the processors. The memories include a ROM in which programs and the like are stored, 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 entire vehicle 1. For example, the processor of the control device 42 cooperates with the programs contained in the memory to control the supply of power to the PTC heater 34.

For example, in winter, the driver may want to get into the vehicle 1 and turn on the heater at the same time as starting the engine 12. In such a case, the engine 12 has not yet warmed up, so the PTC heater 34 is turned on. As described above, the power consumption of the heating section 50 of the PTC heater 34 is greatest when it is turned on. For this reason, if the PTC heater 34 is turned on at the same time as starting the engine 12, the maximum power consumption of the PTC heater 34 is superimposed on the power consumption of the starter 24. This may result in a power shortage in the low-voltage wiring 22.

The power consumption of the starter 24 and the PTC heater 34 is greater than that of other accessories connected to the low-voltage wiring. For this reason, the DCDC converter 30 may be made to supply power from the high-voltage wiring 28 to the low-voltage wiring 22 at the same time as the engine 12 starts. However, if the power consumption of the starter 24 superimposed with the maximum power consumption of the PTC heater 34 is to be 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 this embodiment turns on the PTC heater 34 before the engine 12 starts. In other words, when a predetermined heating start condition is met while the engine 12 is stopped, the control device 42 turns on the PTC heater 34. That is, the control device 42 advances the timing of the consumption of power to turn on the PTC heater 34 compared to the timing of the consumption of power to start the engine 12.

Specifically, when the control device 42 receives a command to turn on the PTC heater 34 from a remote communication device carried by the driver while the engine 12 is stopped, the control device 42 turns on the PTC heater 34. The control device 42 may also turn on the PTC heater 34 when the opening or closing of the driver's door is detected while the engine 12 is stopped. The control device 42 may also turn on the PTC heater 34 when the driver's seat is detected by a sensor provided on the driver's seat while the engine 12 is stopped. The control device 42 may also 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 maximum power can be shifted from the timing at which the starter 24 consumes power. This makes it possible to avoid a power shortage in the low-voltage wiring 22 caused by the maximum power consumption of the PTC heater 34 being superimposed on the power consumption of the starter 24.

However, depending on the timing of starting the engine 12, it may not be possible to avoid a power shortage. For example, assume that the driver is detected as seated and the PTC heater 34 is turned on before the engine 12 is started. Now assume that the driver starts the engine 12 without delay after sitting down. In such a case, there is a risk that the engine 12 will start before the power consumption of the heating section 50 becomes sufficiently small. In that case, there is still a risk that a power shortage will occur in the low-voltage wiring 22 due to the power consumption of the starter 24 superimposed on the power consumption of the PTC heater 34.

The control device 42 of this embodiment therefore turns on the PTC heater 34 before starting the engine 12 and derives the total power consumption of the auxiliaries, including the power consumption of the PTC heater, when the engine is started. If the total power consumption at the time when the control device 42 receives a 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.

Figure 4 is a time chart explaining the operation of the control device 42. In the example of Figure 4, it is assumed that at timing T10, the engine 12 is off and a predetermined heating start condition is met. As a result, the control device 42 turns on the PTC heater 34 at timing T10. At timing T10 when the PTC heater 34 is turned on, no power is consumed by the starter 24, so it is possible to avoid a power shortage caused by turning on the PTC heater 34.

The control device 42 also starts the operation of the DCDC converter 30 in parallel with turning on the PTC heater 34. Then, the current flowing through the low-voltage system wiring 22 via the DCDC converter 30, i.e., the current of the DCDC converter 30, increases from the reference value i0 to the first predetermined value i1.

At timing T11 after timing T10, the control device 42 receives a request to start the engine 12. The engine start flag in FIG. 4 is in the on state 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 auxiliary equipment is equal to or greater than a predetermined value at timing T11 when the start request is received. At timing T11, the control device 42 turns off the PTC heater 34 to temporarily reduce the current of the PTC heater 34. At this time, the control device 42 only needs to temporarily reduce the current of the PTC heater 34, and is not limited to turning off all of the heating units 50, and may turn off only some of the heating units 50. Note that if the total power consumption of the auxiliary equipment is less than a predetermined value at timing T11 when the start request is received, the control device 42 may maintain the number of heating units 50 turned on without turning off the heating units 50.

When the current to the PTC heater 34 is temporarily reduced at timing T11, the control device 42 continues 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, the current of the PTC heater 34 is temporarily reduced, so the power consumption of the PTC heater 34 is suppressed. Therefore, even if power is consumed by the starter 24, a power shortage in the low-voltage wiring 22 can be avoided. When the engine 12 is turned on, the heat of the engine 12 causes the temperature of the cooling water to rise.

At timing T13 after timing T12, the start-up operation of the engine 12 is completed. Then, the control device 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, which was temporarily turned off. Because the time from timing T11 to timing T13 is short, the temperature of the PTC heater 34 does not drop much during this time. In addition, because 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 warm-up of the engine 12 is completed.

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

At timing T15 after timing T14, the temperature of the cooling water reaches a predetermined temperature H10, which indicates that the warm-up of the engine 12 is complete. When this happens, the control device 42 turns off the PTC heater 34. Because the warm-up is complete, 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 interior.

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

Figure 5 is a flowchart explaining the flow of operation of the control device 42. When a predetermined heating start condition is met, the control device 42 executes the series of processes in Figure 5.

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

If the current SOC is less than the predetermined value (NO in S10), the control device 42 ends the series of processes. In this case, since the SOC of the high-voltage battery 26 is low, the supply of power from the high-voltage system wiring 28 to the low-voltage system wiring 22 and the turning on of the PTC heater 34 are not executed. The control device 42 may notify the driver that the current SOC is less than the predetermined value and prompt the driver to charge the high-voltage battery 26.

If the current SOC is equal to or greater than the predetermined value (YES in S10), the control device 42 obtains the interior temperature from the interior temperature detection unit 38 and the outside air temperature from the outside air temperature detection unit 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 air temperature (S12). For example, a map that associates the temperature inside the vehicle, the outside air temperature, and the number of heating units 50 is stored in advance in the memory of the control device 42. For example, this map is set so that the number of heating units 50 increases as each temperature is lower. 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 operation of the DCDC converter 30, the control device 42 turns on the heating units 50 of the PTC heaters 34 by the number derived in step S12 (S14).

Next, the control device 42 derives the total power consumption of the auxiliaries (S15). For example, a representative value of the standby power of the entire auxiliaries before the engine 12 is started, and a representative value of the power consumption of the starter 24 when the engine 12 is started are stored in advance in the memory of the control device 42. The control device 42 acquires the current current value of the PTC heater 34, and derives the current power consumption of the PTC heater 34 from the acquired current value. The control device 42 sums up 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 control device 42 determines whether or not a request to start the engine 12 has been received (S16). If a request to start the engine 12 has not been received (NO in S16), the control device 42 returns to step S15 and repeats the derivation of the total power consumption until a request to start the engine 12 is received. Note that if the current SOC becomes equal to or lower than a predetermined value before a request to start the engine 12 is received, the control device 42 may turn off the PTC heater 34 and stop the operation of the DCDC converter 30.

When a request to start the engine 12 is received (YES in S16), the control device 42 determines whether the total power consumption derived in step S15 is equal to or greater than a predetermined threshold (S17). The predetermined threshold is set, for example, based on the step-down capability of the DCDC converter 30. 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 derives the number of heating units 50 to which current is flowing, that is, the number of heating units 50 to be turned off (S20). For example, a map that associates the difference between the total power consumption and the predetermined threshold with the number of heating units 50 to be turned off is stored in advance in the memory of the control device 42. This map is set so that the greater the difference between the total power consumption and the predetermined threshold, the greater the number of heating units 50 to be turned off. The control device 42 derives the difference between the current total power consumption and the predetermined threshold, and applies this map to derive the number of heating units 50 to be turned off.

Next, the control device 42 turns off the heating units 50 of the PTC heater 34 by the number derived in step S20 to reduce the current of the PTC heater 34 (S21). This reduces the power consumption in the low-voltage wiring 22 by the number of heating units 50 that are turned off, and even if the engine 12 is started by the starter 24, a power shortage in the low-voltage wiring 22 can be avoided. Note that the memory of the control device 42 may set a priority order for the heating units 50 to be turned on among the multiple heating units 50. The control device 42 may turn off the heating units 50 that are on by the number derived in step S20, in order of decreasing priority.

Next, the control device 42 transmits a start command to the starter 24 to start the engine 12 (S22). In response to the start command, the starter 24 starts the engine 12.

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

When the starting operation of the engine 12 is completed (YES in S23), the control device 42 increases the current of the PTC heater 34 (S24) by turning on the heating unit 50 that was turned off in step S21, and proceeds to the processing of step S30. In other words, the control device 42 returns the power consumption of the PTC heater 34 to the power consumption immediately before the heating unit 50 was turned off, by passing a current through the heating unit 50 that was cut off in step S21. The starter 24 does not consume power after the starting operation of the engine 12 is completed. Therefore, even if the power consumption of the PTC heater 34 is returned after the starting operation of the engine 12 is completed, a power shortage in the low-voltage wiring 22 can be avoided.

If the total power consumption is less than the predetermined threshold in step S17 (NO in S17), the control device 42 sends a start command to the starter 24 (S26) and proceeds to the processing of step S30. This is because the total power consumption is less than the predetermined threshold, so that starting the engine 12 will not cause a power shortage in the low-voltage wiring 22.

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

If the warm-up is not complete (NO in S30), the control device 42 waits until the warm-up is complete. If the warm-up is complete (YES in S30), the control device 42 turns off all heating elements 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 this embodiment, if the total power consumption of the accessories at the time when the engine 12 start request is received is equal to or greater than a predetermined threshold, the current of the PTC heater 34 is temporarily reduced before the engine 12 is started.

Therefore, the heating device 10 of the vehicle 1 of this embodiment can perform the heating function while avoiding power shortages in the low-voltage wiring 22.

In addition, in the heating device 10 of the vehicle 1 of this embodiment, the peak power consumption 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 can be prevented from increasing.

In the above embodiment, the heating device 10 of the vehicle 1 is 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 in which a PTC heater 34 is installed inside a seat to heat the seat.

Although an embodiment of the present invention has been described above with reference to the attached drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

REFERENCE SIGNS LIST 1 vehicle 10 heating device 12 engine 22 low voltage wiring 24 starter 26 high voltage battery 28 high voltage wiring 30 DCDC converter 34 PTC heater 42 control device 50 heating section

Claims (3)

a PTC heater that is heated according to the electrical resistance characteristics of a positive temperature coefficient thermistor;
A control device that controls the supply of power to the PTC heater;
a DC-DC converter connected to a low-voltage system wiring to which a starter for starting an engine is electrically connected and to a high-voltage system wiring to which a high-voltage battery having a voltage higher than that of the low-voltage system wiring is electrically connected, the DC-DC converter stepping down a DC voltage of the high-voltage system wiring and supplying the DC voltage to the low-voltage system wiring;
Equipped with
the PTC heater is electrically connected to the low-voltage wiring;
The control device includes:
one or more processors;
one or more memories coupled to the processor;
having
The processor operates in conjunction with a program contained in the memory;
turning on the PTC heater and starting operation of the DCDC converter before starting the engine;
A total power consumption of the auxiliary devices including the power consumption of the PTC heater when the engine is started is derived;
If the total power consumption at the time when a start request to start the engine is received 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 current to the PTC heater that has been decreased after the engine starting operation is completed;
2. A vehicle heating system according to claim 1. The PTC heater has one or more heating parts that generate heat in response to a current flowing therethrough,
The processor,
Before the engine is started, a current is passed through any one or more of the one or more heating sections to turn on the PTC heater;
If the total power consumption at the time when the start request is received is equal to or greater than a predetermined threshold, a current to any one or more of the heating units to which a current is flowing is cut off, thereby reducing a current to the PTC heater.
3. A vehicle heating system according to claim 1 or 2.

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