Vehicle heating system

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

[Technical field]

[0001] The present invention relates to a vehicle heating system. [Background technology]

[0002] 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 gets in. In this 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 gets in. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-11686 A Summary of the Invention [Problem to be solved by the invention]

[0004] A PTC (Positive Temperature Coefficient) heater may be installed as a heat source for the vehicle heating system. The power consumption of a PTC heater is the largest when it is turned on, and decreases over time. In addition, the power consumption of the starter is large when the engine is started. 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.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a vehicle heating device capable of avoiding power shortages. [Means for solving the problem]

[0006] 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 said processor; having The processor operates in conjunction with a program contained in the memory; The above The PTC heater is turned on before the engine starts. At the same time, the DC-DC converter is started to operate. A total power consumption of auxiliary devices including a 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. Effect of the Invention

[0007] According to the present invention, it is possible to avoid power shortages. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a vehicle to which a heating device according to this embodiment is applied. [Diagram 2] FIG. 2 is a diagram showing an example of the change in temperature over time in the heating portion of the PTC heater. [Diagram 3] FIG. 3 is a diagram showing an example of the change over time in power consumption in the heating portion of the PTC heater. [Figure 4] FIG. 4 is a time chart illustrating the operation of the control device. [Diagram 5] FIG. 5 is a flowchart illustrating the flow of operations of the control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not shown.

[0010] 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 wiring 22, a starter 24, a high-voltage battery 26, and high-voltage wiring 28.

[0011] 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, which will be described later. Hereinafter, devices connected to the low-voltage system wiring 22, such as the starter 24, may be referred to as accessories.

[0012] 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.

[0013] 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.

[0014] The DCDC converter 30 is located between the low-voltage wiring 22 and the high-voltage wiring 28. The DCDC converter 30 is electrically connected to the low-voltage wiring 22 and is also 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.

[0015] The blower fan 32 is electrically connected to the low-voltage wiring 22. The blower fan 32 supplies air to a heat exchanger of the vehicle-mounted air conditioner, and sends the air after heat exchange into the vehicle interior.

[0016] The coolant for cooling the engine 12 is guided to a heat exchanger of the vehicle air conditioner. When a sufficient amount of time has passed since the engine 12 was started, the temperature of the engine 12 coolant rises to, for example, about 80°C. When the coolant reaches such a temperature, the coolant can serve as a heat source for the heat exchanger. In other words, when the engine 12 has finished warming up, heating can be performed using the heat of the engine 12 that is transferred through the coolant.

[0017] However, before the engine 12 has finished warming up, the temperature of the engine 12 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.

[0018] Therefore, in this embodiment, the coolant for the engine 12 is guided to a heat exchanger of the vehicle air conditioner, and the PTC heater 34 is installed in the heat exchanger of the vehicle air conditioner. As will be described later, before the engine 12 is completely warmed up, the PTC heater 34 is turned on to provide a heating function using the heat of the PTC heater 34.

[0019] The PTC heater 34 is electrically connected to the low-voltage wiring 22. The PTC heater 34 has one or more heating units 50 that generate heat according to the current flowing therethrough. 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 case where the PTC heater 34 has multiple heating units 50, each of the multiple heating units 50 can be turned on independently. In other words, in the PTC heater 34, the number of heating units 50 to be turned on can be changed as desired.

[0020] The heating portion 50 of the PTC heater 34 is heated in accordance with the electrical resistance characteristics of a positive temperature coefficient thermal resistor.

[0021] Fig. 2 is a diagram showing an example of a time transition of temperature in the heating unit 50 of the PTC heater 34. Fig. 3 is a diagram showing an example of a time transition of power consumption in the heating unit 50 of the PTC heater 34. The time axis in Fig. 2 and the time axis in Fig. 3 are assumed to be the same. In Fig. 2 and Fig. 3, it is assumed that the heating unit 50 is turned on at timing T0.

[0022] 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 suddenly rises in the relationship between the temperature and the electrical resistance value.

[0023] When the temperature of the heating part 50 is lower than the Curie temperature H1, the electrical resistance value of the heating part 50 is low, and a current easily flows through the heating part 50. Therefore, the heating part 50 generates heat in accordance with the current flowing therethrough, and as shown in FIG. 2, the temperature of the heating part 50 rises from temperature H0.

[0024] Furthermore, when the temperature of the heating unit 50 is temperature H0, current flows easily as described above, and therefore the power consumption of the heating unit 50 becomes large, as shown in Fig. 3 as power consumption P0. Then, when the temperature of the heating unit 50 rises from temperature H0, the electrical resistance value of the heating unit 50 increases, and therefore the power consumption of the heating unit 50 decreases from power consumption P0, as shown in Fig. 3.

[0025] 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.

[0026] At timing T1, since it becomes difficult for the current to flow as described above, the power consumption of the heating unit 50 becomes power consumption P1, which is smaller than the power consumption P0, as shown in Fig. 3. Then, after timing T1, the temperature of the heating unit 50 is maintained at the Curie temperature H1, so the power consumption of the heating unit 50 is maintained at the power consumption P1, as shown in Fig. 3.

[0027] In this way, the power consumption of the heating unit 50 is the largest at the timing T0 when the heating unit 50 is turned on, and the power consumption decreases as time passes. The time from timing T0 to timing T1 depends on the temperature inside the vehicle or the outside temperature, but is, for example, about several minutes.

[0028] Moreover, 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.

[0029] Returning to Fig. 1, the coolant temperature detector 36 is provided in the flow path of the coolant of the engine 12. The coolant temperature detector 36 detects the temperature of the coolant of the engine 12. The interior temperature detector 38 detects the temperature inside the vehicle. The outside air temperature detector 40 detects the outside air temperature.

[0030] 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 stored in the memory to control the entire vehicle 1. For example, the processor of the control device 42 cooperates with the programs stored in the memory to control the supply of power to the PTC heater 34.

[0031] For example, in winter, the driver may get into the vehicle 1 and want to turn on the heater at the same time as the engine 12 starts. In this case, the engine 12 has not yet been warmed up, so the PTC heater 34 is turned on. As described above, the power consumption of the heating unit 50 of the PTC heater 34 is the largest when the heater is turned on. Therefore, if the PTC heater 34 is turned on at the same time as the engine 12 starts, the maximum power consumption of the PTC heater 34 is superimposed on the power consumption of the starter 24. This may cause a power shortage in the low-voltage wiring 22.

[0032] In addition, the power consumption of the starter 24 and the PTC heater 34 is larger 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 timing as the start of the engine 12. 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.

[0033] Therefore, the control device 42 of this embodiment turns on the PTC heater 34 before starting the engine 12. In other words, when a predetermined heating start condition is satisfied 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 power consumption for turning on the PTC heater 34 compared to the timing of power consumption for starting the engine 12.

[0034] 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. Also, when the control device 42 detects that the driver's door is opened or closed while the engine 12 is stopped, the control device 42 may turn on the PTC heater 34. Also, when the control device 42 detects that the driver is seated by a sensor provided on the driver's seat while the engine 12 is stopped, the control device 42 may turn on the PTC heater 34. Also, when the control device 42 detects that the driver is seated by an optical camera, a thermal camera, or the like while the engine 12 is stopped, the control device 42 may turn on the PTC heater 34.

[0035] By turning on the PTC heater 34 before starting the engine 12, the timing at which the maximum power consumption of the PTC heater 34 occurs can be shifted from the timing at which the power consumption of the starter 24 occurs. 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.

[0036] However, depending on the start timing of the engine 12, there are cases where the power shortage cannot be avoided. For example, assume that the driver's seating is detected and the PTC heater 34 is turned on before the engine 12 is started. Here, assume that the driver starts the engine 12 without delay after sitting in the seat. In such a case, the engine 12 may be started before the power consumption of the heating unit 50 becomes sufficiently small. In that case, the power consumption of the starter 24 and the power consumption of the PTC heater 34 are superimposed, and a power shortage may still occur in the low-voltage wiring 22.

[0037] Therefore, the control device 42 of this embodiment turns on the PTC heater 34 before starting the engine 12, and derives the total power consumption of the accessories, including the power consumption of the PTC heater, in the case where 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.

[0038] Fig. 4 is a time chart for explaining the operation of the control device 42. In the example of Fig. 4, it is assumed that the engine 12 is off and a predetermined heating start condition is satisfied at timing T10. 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 that a power shortage caused by turning on the PTC heater 34 can be avoided.

[0039] In addition, the control device 42 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 through 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.

[0040] At a timing T11 after the timing T10, the control device 42 receives a request to start the engine 12. The engine start flag in Fig. 4 is kept in the on state from the reception of the start request until the start operation of the engine 12 is completed.

[0041] In FIG. 4, it is assumed that the total power consumption of the auxiliary devices is equal to or greater than a predetermined value at the timing T11 when the start request is received. The control device 42 turns off the PTC heater 34 at the timing T11 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 some of the heating units 50. Note that, if the total power consumption of the auxiliary devices is less than a predetermined value at the timing T11 when the start request is received, the control device 42 may maintain the number of heating units 50 that are turned on without turning off the heating units 50.

[0042] When temporarily reducing the current of the PTC heater 34 at timing T11, the control device 42 causes the DC-DC converter 30 to continue operating, and causes the current of the DC-DC converter 30 to be maintained at the first predetermined value i1.

[0043] At a timing T12 after the 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 that 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 system wiring 22 can be avoided. When the engine 12 is turned on, the heat of the engine 12 causes the temperature of the coolant to rise.

[0044] Assume that the starting operation of the engine 12 is completed at timing T13 after timing T12. 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 that was temporarily turned off. Since 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, 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 warm-up of the engine 12 is completed.

[0045] 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. Therefore, the air is heated by the heat of the PTC heater 34, and the heated air is sent into the vehicle interior.

[0046] At a timing T15 after the timing T14, the temperature of the cooling water reaches a predetermined temperature H10 indicating the completion of warming up the engine 12. When this happens, the control device 42 turns off the PTC heater 34. Since the warming up is completed, the air is heated by the heat of the engine 12 transferred to the cooling water, even if the PTC heater 34 is turned off, and the heated air is sent into the vehicle interior.

[0047] 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 when the PTC heater 34 is turned off. This is because turning off the PTC heater 34 reduces the power required in the low-voltage wiring 22.

[0048] Fig. 5 is a flow chart illustrating the flow of operations of the control device 42. When a predetermined heating start condition is met, the control device 42 executes a series of processes in Fig. 5.

[0049] 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 exemplified value and can be set arbitrarily.

[0050] 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. Note that the control device 42 may notify the driver that the current SOC is less than the predetermined value and cause the driver to charge the high-voltage battery 26.

[0051] If the current SOC is equal to or higher than the predetermined value (YES in S10), the control device 42 obtains the temperature inside the vehicle from the interior temperature detector 38 and the outside air temperature from the outside air temperature detector 40 (S11).

[0052] 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.

[0053] 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).

[0054] Next, the control device 42 derives the total power consumption of the accessories (S15). For example, a representative value of the standby power of the entire accessories 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 a 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.

[0055] Next, the control device 42 determines whether or not a start request for the engine 12 has been received (S16). If a start request for 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 start request for the engine 12 is received. Note that, if the current SOC becomes equal to or lower than a predetermined value before the start request for the engine 12 is received, the control device 42 may turn off the PTC heater 34 and stop the operation of the DC-DC converter 30.

[0056] When a request to start the engine 12 is received (YES in S16), the control device 42 judges 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 DC-DC converter 30. For example, the predetermined threshold is set to a larger value as the step-down capability of the DC-DC converter 30 is higher.

[0057] 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 to be cut off, that is, the number of heating units 50 to be turned off, among the heating units 50 through which current is flowing (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 number of heating units 50 to be turned off increases as the difference between the total power consumption and the predetermined threshold increases. The control device 42 derives the difference between the current total power consumption and the predetermined threshold, and applies this to the map to derive the number of heating units 50 to be turned off.

[0058] 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 system 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 system wiring 22 can be avoided. Note that the memory of the control device 42 may set a priority order of 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 by the number derived in step S20, in order of decreasing priority, among the heating units 50 that are on.

[0059] 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.

[0060] Next, the control device 42 determines whether or not the starting operation of the engine 12 is completed (S23). If the starting operation of the engine 12 is not completed (NO in S23), the control device 42 waits until the starting operation of the engine 12 is completed.

[0061] 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 process 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.

[0062] In step S17, if 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, since the total power consumption is less than the predetermined threshold, even if the engine 12 is started, no power shortage occurs in the low-voltage system wiring 22.

[0063] 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 detection unit 36. If the temperature of the coolant is equal to or higher than a predetermined temperature, the control device 42 determines that the warm-up is completed.

[0064] If the warm-up is not completed (NO in S30), the control device 42 waits until the warm-up is completed. If the warm-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 DC-DC 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.

[0065] As described above, in the heating device 10 of the vehicle 1 of this embodiment, the PTC heater 34 is turned on before starting the engine 12. Then, in the heating device 10 of the vehicle 1 of this embodiment, if the total power consumption of the accessories at the timing when the start request of the engine 12 is received is equal to or greater than a predetermined threshold, the current of the PTC heater 34 is temporarily reduced and then the engine 12 is started.

[0066] Therefore, according to the heating device 10 of the vehicle 1 of this embodiment, it is possible to avoid a power shortage in the low-voltage wiring 22 and to exert the heating function.

[0067] In addition, in the heating device 10 of the vehicle 1 of this embodiment, the peak of power consumption in the low-voltage wiring 22 is suppressed, so that the size of the DC-DC converter 30 that supplies power to the low-voltage wiring 22 can be prevented from increasing.

[0068] 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 the PTC heater 34 is installed inside a seat to heat the seat.

[0069] Although the 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 think of various modified or altered examples within the scope of the claims, and it is understood that such examples also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0070] 1 vehicle 10 Heating equipment 12 Engine 22 Low voltage wiring 24 Starter 26 High Voltage Battery 28 High voltage wiring 30 DC-DC Converter 34 PTC heater 42 Control device 50 Heating section

Claims

1. 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.

2. 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.

3. 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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