Power supply control apparatus and temperature control method

Abstract

A power control device controls temperature of an apparatus having a cooling mechanism and a heat generating component. The power control device includes a nonvolatile storage unit that stores information indicating unique characteristics including thermal resistance and thermal capacity of the apparatus for each current of the heat generating component, a current measurement unit configured to measure a current flowing through the heat generating component, a temperature measurement unit configured to measure a current temperature of the heat generating component, and a control unit configured to perform cooling control on the apparatus. The control unit estimates a temperature rise value after a certain delay time based on the current, the temperature, and the information on the unique characteristics, and performs the cooling control on the apparatus based on the estimated temperature after the delay time.

Description

Technical Field

[0001] This disclosure relates to a power control device and a temperature control method. Background Technology

[0002] For example, in recent years, an increasing number of electrical components containing semiconductor devices have been generating significant amounts of heat when powered on, particularly for devices installed in vehicles. Furthermore, devices installed in vehicles need to be smaller and lighter than those in the prior art.

[0003] However, when attempting to provide sufficient cooling capacity to avoid the adverse effects of temperature rise due to heat generation, radiators (heat sinks), cooling fans, etc., increase the size and weight of the device. Furthermore, insufficient cooling capacity can lead to malfunctions due to abnormal temperature increases.

[0004] For example, patent document JP-A-2018-180257 discloses a temperature control method for an image monitoring device. Patent document JP-A-2018-180257 discloses adjusting the current flowing through the cooling unit when the measured temperature exceeds the set temperature.

[0005] On the other hand, patent document JP-A-H08-33104 discloses a cooling method for an electric power conversion device in an electric vehicle. JP-A-H08-33104 discloses a technique for saving electrical energy consumed in operating a cooling fan and reducing the noise of the cooling fan. JP-A-H08-33104 illustrates the following: detecting and controlling the temperature Tfn of the thermal radiation fan mounted on the semiconductor device of the electric motor power conversion device of the electric vehicle, the current value Ia flowing through the device, and the voltage value Vdc; estimating the junction temperature Tjn of the semiconductor device; and controlling the cooling fan speed when the junction temperature Tjn is equal to or lower than the maximum usage setting value Tjmax. The configuration of the device described in JP-A-H08-33104 includes a heat loss calculation circuit, a thermal resistance calculation circuit, and a thermal resistance fan speed data table.

[0006] For example, as in patent document JP-A-H08-33104, calculations can be performed considering heat loss and thermal resistance to improve the accuracy of temperature control. However, in actual temperature control, there is a time delay between the point in time when the control variable changes and the point in time when the changed control variable is reflected in the output temperature. Therefore, there is a tendency for the control variable to be excessive or insufficient, or for the temperature change of the control result to become larger. In addition, there are individual differences specific to each device in various equipment. Therefore, there is a possibility that the performance of temperature control will vary due to the influence of individual differences. Summary of the Invention

[0007] In view of the foregoing, this disclosure has been made, and the purpose of this disclosure is to provide a power control device and a temperature control method that can prevent temperature from changing beyond what is necessary and is unlikely to be affected by individual differences between devices.

[0008] To achieve the above objectives, a power control device according to this disclosure is as follows. A power control device for controlling the temperature of a device, wherein a cooling mechanism and a heating element that heats up when energized are mounted on the device, the power control device comprising: a non-volatile storage unit storing information indicating specific characteristics, including the thermal resistance and thermal capacity of the device for each current of the heating element; a current measuring unit configured to measure a current I flowing through the heating element; a temperature measuring unit configured to measure a current T1 of the heating element; and a control unit configured to perform cooling control on the device, wherein the control unit estimates a temperature rise ΔT2 after a specific delay time t2 from the measurement of the current temperature T1 based on the current I measured by the current measuring unit, the temperature T1 measured by the temperature measuring unit, and the information about the specific characteristics stored in the non-volatile storage unit, and performs the cooling control on the device based on the estimated temperature T2 after the delay time t2.

[0009] To achieve the above objectives, a temperature control method according to this disclosure is as follows. A temperature control method for controlling the temperature of a device having a cooling mechanism and a heating element heated by electricity mounted thereon, the temperature control method comprising: calculating and storing information indicating specific characteristics in a calibration process, the specific characteristics including the thermal resistance and thermal capacity of the device for each current of the heating element; acquiring a current temperature T1 and a current I flowing through the heating element by measurement; estimating a temperature rise ΔT2 after a specific delay time t2 from the measurement of the current temperature T1 in an estimation process based on the stored thermal resistance and thermal capacity and the acquired current I; and performing the cooling control based on the estimated temperature after the delay time t2, wherein the calibration process is performed prior to the estimation process.

[0010] The power control device and temperature control method disclosed herein can prevent temperature changes from exceeding the necessary level, while being less likely to be affected by individual differences between devices.

[0011] The present disclosure has been briefly described above. The details of the disclosure will be further elucidated by reading the aspects for implementing the disclosure described below with reference to the accompanying drawings. Attached Figure Description

[0012] Figure 1This is a circuit diagram illustrating an example configuration of a temperature control device according to an embodiment of the present disclosure.

[0013] Figure 2 It is a perspective view showing the state of the radiator being installed near the heat source to be cooled.

[0014] Figure 3 It is a perspective view showing the radiator removed from the vicinity of the heat source to be cooled.

[0015] Figure 4 This is a flowchart illustrating a specific example of the calibration process for a temperature control device.

[0016] Figure 5 This is a graph illustrating an example of the relationship between current and thermal resistance.

[0017] Figure 6 This is a flowchart illustrating an example of temperature control operation of a temperature control device. Detailed Implementation

[0018] Specific embodiments according to this disclosure will be described with reference to the accompanying drawings. In the following description, an example of the power control device according to this disclosure being applied to a temperature control device installed in a vehicle will be described; however, this disclosure is not limited to this example and can be applied to various power control devices, such as DC / DC converters, each having a switching function.

[0019] <Overview of Temperature Control Equipment>

[0020] <Uses of the equipment>

[0021] Figure 1 An example configuration of a temperature control device 100 (power control device) according to an embodiment of the present disclosure is shown.

[0022] Figure 1 The temperature control device 100 shown can be used to achieve control in order to effectively cool electrical components, etc., under appropriate conditions. These electrical components have components such as various power semiconductor devices that generate heat according to energized operation.

[0023] For example, when a power semiconductor device is powered on, power loss occurs due to its internal resistance, and the temperature rises due to the heat generated corresponding to the power loss. Furthermore, when the temperature rises abnormally, the likelihood of malfunction or failure in components such as semiconductors is high; therefore, cooling is necessary to stop the abnormal temperature rise.

[0024] As a common cooling method, a heat sink (heat fin) is used. In many cases, forced cooling is achieved by using an electric fan or a Peltier element. That is, by rotating an electric fan to blow air, cooling can be achieved based on the amount of air blown. Additionally, by energizing a Peltier element, the vicinity of the heat source can be cooled.

[0025] However, when cooling capacity is increased more than required, large radiators and large electric fans are needed. Furthermore, the high-speed rotation of the electric fan increases power consumption and can generate noise from blowing air, mechanical vibration, etc. Additionally, Peltier elements consume a significant amount of power. Especially in the case of devices installed in vehicles, it is necessary to reduce size, weight, and power consumption; therefore, achieving sufficient cooling performance without increasing the external dimensions, weight, or power consumption of the cooling mechanism is crucial.

[0026] Configuration of Temperature Control Device 100

[0027] Figure 1 The temperature control device 100 shown implements a control function to maintain the temperature rise caused by heat generated at a portion of the switching circuit 12 within an appropriate range. Furthermore, the temperature control device 100 performs temperature control based on device-specific data obtained through calibration, which will be described later. However, when the predetermined specific data is stored in a non-volatile memory 28 or the like, the temperature control device 100 does not require calibration. Therefore, only the functions and components required for calibration need not necessarily be installed on the temperature control device 100.

[0028] exist Figure 1 For example, the device (controlled device) controlled by the temperature control device 100 includes a power supply 11, a switching circuit 12, a load 13, and a gate driver 14. The load 13 corresponds to, for example, a motor installed in a vehicle, a lamp for lighting, a heater, etc.

[0029] In this controlled device, DC power supplied from power source 11 is supplied to load 13 through power line 15, input terminal 12a, switching circuit 12, output terminal 12b, resistor 25 and current path 16.

[0030] The switching circuit 12 includes two semiconductor switching elements FET1 and FET2 connected in series with opposite polarities. The semiconductor switching elements FET1 and FET2 are power MOS field-effect transistor (FET) devices.

[0031] In other words, the drain terminal (D) of semiconductor switching element FET1 is connected to the input terminal 12a, and the source terminals (S) of semiconductor switching element FET1 and semiconductor switching element FET2 are connected to each other. The drain terminal (D) of semiconductor switching element FET2 is connected to the output terminal 12b.

[0032] By applying an electrical signal SG1, which is a binary signal, to the gate terminals (G) of the semiconductor switching elements FET1 and FET2 via the gate driver 14, the semiconductor switching elements FET1 and FET2 can be switched between on (conducting) and off (not conducting). That is, the on / off state between the input terminal 12a and the output terminal 12b in the switching circuit 12 can be switched using the electrical signal SG1.

[0033] When the switching circuit 12 is in the ON state, current I flows through current path 16, and power is supplied to load 13. When the switching circuit 12 is in the OFF state, current I is cut off, and therefore the power supplied to load 13 is cut off. Furthermore, for example, when the switching circuit 12 is controlled by pulse width modulation (PWM), the magnitude (RMS value) of current I can be adjusted.

[0034] Meanwhile, in order to measure the current I in the switching circuit 12 of the controlled device, a resistor 25 and an amplifier 22 are provided. The resistance of the resistor 25 is very small, so that the current I is unaffected. The amplifier 22 detects the voltage drop caused by the current I flowing through the resistor 25 and generates an amplified electrical signal SG3.

[0035] Furthermore, amplifier 21 is configured to detect the potential difference between the input terminal 12a and the output terminal 12b of the switching circuit 12. Amplifier 21 detects the potential difference without affecting the operation of the switching circuit 12 and generates an electrical signal SG4 corresponding to the potential difference.

[0036] Meanwhile, in the controlled device, the energization of the switching circuit 12 generates power losses and heat within the semiconductor switching elements FET1 and FET2. In other words, the semiconductor switching elements FET1 and FET2 act as heat sources, and their temperature rises. To prevent this temperature rise, a cooling unit 17 is provided. In addition to a heat sink, which will be described later, the cooling unit 17 also includes a cooling mechanism capable of active control, such as an electric fan or a Peltier element.

[0037] The heat source temperature measuring device 24 includes a sensor capable of detecting temperature, such as a thermistor, and is capable of detecting the temperature near the semiconductor switching elements FET1 and FET2, which serve as heat sources. The heat source temperature measuring device 24 generates an electrical signal SG2 indicating the detected temperature.

[0038] Temperature measuring device 23 detects the temperature at a location slightly away from the heat source. Specifically, it detects the temperature of the outer surface of the heat sink cooling the semiconductor switching elements FET1 and FET2. In this embodiment, for example, a non-contact measuring device such as a radiation thermometer is used as temperature measuring device 23. Temperature measuring device 23 generates an electrical signal SG5 indicating information about the detected temperature.

[0039] Figure 1 The temperature control device 100 shown is controlled by a control unit 26. In this embodiment, a microcomputer is used as the control unit 26. The control unit 26 includes non-volatile memory 28.

[0040] Control unit 26 can switch the switching circuit 12 on / off by controlling the electrical signal SG1 output from port P1. Electrical signal SG2 output from heat source temperature measuring device 24 is input to port P2 of control unit 26. Electrical signal SG3 output from amplifier 22 is input to port P3 of control unit 26. Electrical signal SG4 output from amplifier 21 is input to port P4 of control unit 26.

[0041] The control unit 26 can sequentially sample the analog levels of the electrical signals SG2 to SG4 input to ports P2 to P4 respectively, and convert the analog levels into digital signals to obtain information about each signal. Additionally, the control unit 26 can acquire information about the electrical signal SG5 output from the temperature measuring device 23 via, for example, communication at port P5.

[0042] Furthermore, the control unit 26 can control the state of the cooling unit 17 by outputting an electrical signal SG6 to port P6. That is, the cooling unit 17 can be controlled by the electrical signal SG6 to promote cooling, and the cooling unit 17 can be controlled by the electrical signal SG6 to suppress cooling.

[0043] The operation unit 27, connected to port P7 of the control unit 26, can receive instructions based on user switching operations. The control unit 26 can perform controls such as mode switching according to the instructions from the operation unit 27.

[0044] <Example of a controlled object>

[0045] Figure 2 and 3 The image shows an example of the appearance near the heat source to be cooled. Figure 2 The image shows the state with the heat sink installed. Figure 3 The image shows the state after the heatsink has been removed.

[0046] In a device to be cooled (to be controlled), for example, such as Figure 3 As shown, circuit board 52 is mounted on housing 51, and heat source 53 is connected to circuit board 52. Heat source 53 corresponds to Figure 1 The semiconductor switching elements FET1 and FET2 are used in the process. Figure 1 The heat source temperature measuring device 24 shown is installed at a location that can measure the temperature near the heat source 53, that is, at the temperature measuring point TP1.

[0047] The heat generated by the energization of heat source 53 is transferred to the metal busbar 54 via thermal conduction, and further transferred from the busbar 54 to the heat sink 55 via thermal conduction. To achieve sufficient cooling performance, Figure 2 The radiator 55 shown has sufficient size and a large number of blades to increase the surface area that can be further exposed to the outside air.

[0048] Furthermore, sufficient cooling performance cannot be obtained solely through natural air cooling using radiator 55. Therefore, by using... Figure 1 The cooling unit 17 shown includes an electric fan that blows air, forcing the air in contact with the surface of the radiator 55 to flow, thereby improving cooling performance. Furthermore, by increasing the rotational speed of the electric fan, the amount of air blown per unit time can be increased, and the overall cooling performance of the cooling unit 17, including the radiator 55 and the electric fan, can be improved.

[0049] Figure 1 The temperature measuring device 23 shown measures the temperature. Figure 2 The temperature at the temperature measurement point TP2 shown. That is, the surface temperature of the heat sink 55 is measured near the center of the outer surface of the heat sink 55. The temperature measuring device 23 is only used for calibration as described later and is not used for subsequent actual cooling control.

[0050] <Calibration Process>

[0051] The calibration process for temperature control device 100 is as follows: Figure 4 As shown in the diagram. That is, in order to obtain data indicating the characteristics specific to the device to be cooled (controlled), Figure 1 The control unit 26 of the temperature control device 100 shown executes... Figure 4 The calibration process shown.

[0052] For example, when a user operates the operation unit 27, a mode switching command is given to the control unit 26, and it can be started by executing a pre-installed program. Figure 4 The calibration process is described below.

[0053] The control unit 26 first controls the electrical signal SG1 and performs power-on control in S11, causing the current I to flow through the switching circuit 12 at a first predetermined value (i1). Under this control, the current I with the first predetermined value i1 flows from the power supply 11 to the load 13 through the semiconductor switching elements FET1 and FET2 in the switching circuit 12.

[0054] In the next step S12, the control unit 26 simultaneously measures the temperature at two points using the heat source temperature measuring device 24 and the temperature measuring device 23 respectively, and detects the temperature difference ΔT(i1) between the two points corresponding to the current I with a first predetermined value i1.

[0055] When performing calibration, it is necessary to eliminate the effects of instantaneous temperature changes that are unrelated to the static characteristics of the device, and therefore the measurement should be performed in a temperature-saturated and stable state. That is, the measurement of S12 should be performed after a sufficient time has elapsed following the change in current I and when the temperature is sufficiently stable.

[0056] In the next step, S13, the control unit 26 observes the voltage of the electrical signal SG4. As a result, it detects the potential difference ΔV between the input and output of the switching circuit 12. The potential difference ΔV detected in S13 is associated with a first predetermined value i1 of the current I.

[0057] In S14, based on the current I corresponding to the first predetermined value i1 and the potential difference ΔV obtained in S13, the control unit 26 calculates the power loss P(i1) in the switching circuit 12 by the following equation.

[0058] P(i1)=ΔV×I······(1)

[0059] Next, in S15, the control unit 26 changes the control quantity of the electrical signal SG1 and performs power-on control, causing the current I to flow through the switching circuit 12 at a second predetermined value (i2). Therefore, the current I with the second predetermined value i2 flows from the power supply 11 to the load 13 through the semiconductor switching elements FET1 and FET2 in the switching circuit 12.

[0060] In the next step, S16, the control unit 26 simultaneously measures the temperature at two points using the heat source temperature measuring device 24 and the temperature measuring device 23 respectively, and detects the temperature difference ΔT(i2) between the two points corresponding to the current I with a second predetermined value i2. Furthermore, as in S12, the measurement in S16 is performed after a sufficient time has elapsed following the change in current I and when the temperature is sufficiently stable.

[0061] In the next step, S17, the control unit 26 observes the voltage of the electrical signal SG4 again. As a result, the potential difference ΔV between the input and output of the switching circuit 12 is detected. The potential difference ΔV detected in S17 is associated with a second predetermined value i2 of the current I.

[0062] In S18, based on the current I corresponding to the second predetermined value i2 and the potential difference ΔV obtained in S17, the control unit 26 calculates the power loss P(i2) in the switching circuit 12 by the following equation.

[0063] P(i2)=ΔV×I······(2)

[0064] In S19, based on the results obtained in the processes of S11 to S18, the control unit 26 calculates the device-specific thermal resistance Rth [°C / W] for various values ​​of current I.

[0065] Rth(I)=ΔT(I) / P(I)······(3)

[0066] In S20, the control unit 26 calculates the device-specific heat capacity Cth [J / ℃] for the value of current I.

[0067] Specifically, the specific heat is obtained using the following equations (4) and (5) based on the function of thermal storage, and the heat capacity Cth is calculated.

[0068] ΔT1=(Rth×P)×(EXP(-t1 / (Rth×Cth)))···(4)

[0069] Cth=K1×K2······(5)

[0070] ΔT1: The temperature rise of the heat source [°C] after a predetermined current has flowed for a predetermined time.

[0071] Rth: Thermal resistance calculated when a predetermined current flows [°C / W]

[0072] P: Power loss [W] calculated when a predetermined current flows.

[0073] T1: Scheduled time [seconds]

[0074] K1: Specific heat of the component [J / kg℃]

[0075] K2: Weight (estimated) of component (heat sink, plate) [kg]

[0076] EXP(): The exponential function passed as an argument within the parentheses.

[0077] Based on the results obtained in the processing of S11 to S19, the control unit 26 writes data including device-specific thermal resistance Rth and thermal capacity Cth for various values ​​of current I into the non-volatile memory 28 or a predetermined ROM (read-only memory).

[0078] <Example of a property>

[0079] Figure 5 An example is shown of the relationship between the current I flowing through the semiconductor switching elements FET1 and FET2 of the switching circuit 12 and the thermal resistance Rth that affects the temperature change characteristics when the portion of the semiconductor switching elements FET1 and FET2 used as a heat source is cooled.

[0080] exist Figure 5 In the example shown, it is assumed that the relationship between current I and thermal resistance Rth is linear. When the characteristics are linear as described above, such as in... Figure 4 In steps S11 to S18 shown, if the thermal resistance Rth for two types of predetermined current values ​​i1 and i2 can be specified, the thermal resistance Rth corresponding to other current values ​​can also be easily calculated through the calculation in S19. That is, the thermal resistance Rth corresponding to each current value can be obtained based on the difference between any current value and current value i1 or i2 and the slope of the change in thermal resistance Rth.

[0081] Even when the change in thermal resistance Rth is not linear, it is possible to repeat the process for each of three or more predetermined current values. Figure 4 The same process, from S11 to S18, is used to estimate the thermal resistance Rth for any current value through calculation.

[0082] <Temperature Control Operation>

[0083] Figure 6 An example of temperature control operation in temperature control device 100 is shown. During the execution... Figure 6 In the temperature control device 100 shown in the diagram, as Figure 4 The device-specific data obtained from the calibration results shown is pre-stored, for example... Figure 1 The non-volatile memory 28 shown is used.

[0084] In other words, the data corresponding to the thermal resistance Rth and thermal capacity Cth for each of the various current values ​​of the current I flowing through the switching circuit 12 are stored in the non-volatile memory 28. Therefore, the control unit 26 can use the data of thermal resistance Rth and thermal capacity Cth in the non-volatile memory 28 to perform temperature control.

[0085] In this embodiment, Figure 6The constant data of the delay time t2 required for the temperature control shown and the constant data Tth1 and Tth2 indicating two types of temperature thresholds are also predetermined and stored in the non-volatile memory 28.

[0086] Here, the constant data of the delay time t2 indicates the length of the delay time for temperature control and cooling control. In this temperature control, the temperature near the heat source drops below the maximum temperature at which device damage or functional failure occurs, and in this cooling control, operation can be ensured. The delay time t2 is determined by the cooling performance unique to the device.

[0087] The constant data Tth1 is a threshold value indicating the temperature [°C] near the heat source that requires enhanced cooling performance control in the cooling unit 17.

[0088] The constant data Tth2 is a threshold value indicating the temperature [°C] near the heat source that exceeds the cooling performance of the cooling unit 17 or a threshold value of the temperature at which the cooling control cannot be followed and heat generation needs to be suppressed or stopped.

[0089] Therefore, there is a relationship of “Tth1 < Tth2”.

[0090] For example, in Figure 1 the temperature control device 100 shown, the user performs a predetermined input operation using the operation unit 27 so that an instruction for switching to the “estimation mode” can be issued to the control unit 26. When the mode is switched to the “estimation mode”, the control unit 26 executes Figure 6 the normal operation process shown in as the “estimation mode”. The normal operation in Figure 6 will be described below.

[0091] In S31, in order to monitor the current value of the current I flowing through the switch circuit 12, the control unit 26 sequentially samples the electrical signal SG3 and reads its voltage. The control unit 26 obtains data of the thermal resistance Rth corresponding to the current value obtained in S31 from the non-volatile memory 28 (S32). In addition, the control unit 26 obtains data of the heat capacity Cth corresponding to the current value obtained in S31 from the non-volatile memory 28 (S33).

[0092] The control unit 26 samples the electrical signal SG4 and obtains its voltage value as the potential difference ΔV. The potential difference ΔV is the voltage difference between the input and output of the switch circuit 12. Then, the control unit 26 calculates the loss P [W] of the switch circuit 12 as the product of the potential difference ΔV and the value of the current I obtained in S31.

[0093] P = ΔV × I ······ (6)

[0094] In addition, the control unit 26 calculates the temperature rise value Tp corresponding to the loss P at the current time S34.

[0095] Tp = Rth × P ······(7)

[0096] Next, in S35, the control unit 26 uses the delay time t2 of the constant data to calculate the temperature rise value ΔT2 at the time point after the delay time t2 has elapsed from the current time as an estimated value.

[0097] ΔT2 = Tp × (-EXP(t2 / (Rth × Cth))) ······(8)

[0098] The control unit 26 samples the latest electrical signal SG2 and obtains the voltage value as the current temperature T1 of the heat source. Then, it calculates the estimated temperature T2 of the heat source at the time point after the delay time t2 has elapsed from the current time, and in S36, it compares the estimated temperature T2 with the temperature threshold Tth1.

[0099] T2 = T1 + ΔT2 ······(9)

[0100] When the condition "T2 < Tth1" is satisfied, the process proceeds from S36 to S37. In this case, since there is a margin in the current cooling state, the control unit 26 performs control to reduce the cooling performance of the cooling unit 17. Specifically, it reduces the rotational speed of the electric fan. This enables reduction of noise and power consumption.

[0101] When "T2 ≥ Tth1", the process proceeds from S36 to S38, and the estimated temperature T2 is compared with the temperature threshold Tth2. When the condition "Tth2 > T2 ≥ Tth1" is satisfied, the process proceeds from S38 to S39. In this case, since the current cooling performance is not sufficient to reach an appropriate level, the control unit 26 performs control to improve the cooling performance of the cooling unit 17. Specifically, the rotational speed of the electric fan is increased.

[0102] When the condition "T2 ≥ Tth2" is satisfied, the process proceeds from S38 to S40. In this case, since the cooling capacity of the cooling unit 17 is exceeded or the cooling control cannot appropriately follow the temperature change of the heat source, in S40, the control unit 26 stops the output of the electrical signal SG1 in order to cut off the power supply of the switch circuit 12. It should be noted that control can be performed in S40 in order to suppress the power supply of the switch circuit 12.

[0103] <Advantageous effects of the temperature control device>

[0104] According to the above temperature control device 100, by executing Figure 4The calibration process shown can acquire specific data for each current value in the actual device to be cooled, such as thermal resistance Rth. Provided this data is pre-stored in non-volatile memory 28, it can be used by the control unit 26 of the temperature control device 100 to... Figure 6 High-precision temperature control is achieved in the estimation mode shown.

[0105] In addition, Figure 6 In the estimated mode operation shown, the future temperature rise ΔT2 and the estimated temperature T2 are calculated after a delay time t2 from the current time, and the result of comparing the estimated temperature T2 with the thresholds Tth1 and Tth2 is reflected in the control. Therefore, delays in temperature control can be prevented.

[0106] <Supplementary Notes>

[0107] Hereinafter, the characteristics of the embodiments of the power control device and temperature control method according to the present disclosure are briefly summarized in [1] to [4].

[0108] [1] A power control device (temperature control device 100) for controlling the temperature of a device, wherein a cooling mechanism and a heating element that heats up when energized are mounted on the device, the power control device comprising:

[0109] A non-volatile memory cell (non-volatile memory 28) stores information indicating specific characteristics, including the thermal resistance and thermal capacity of the device for each current of the heating element.

[0110] A current measuring unit (resistor 25, amplifier 22) measures the current I flowing through the heating component;

[0111] A temperature measuring unit (heat source temperature measuring device 24) measures the current temperature T1 of the heating element; and

[0112] Control unit (26), which performs cooling control on the device,

[0113] The control unit estimates the temperature rise ΔT2 after a specific delay time t2 from the measurement of the current temperature T1, based on the current I measured by the current measuring unit, the temperature T1 measured by the temperature measuring unit, and information about the specific characteristics stored in the non-volatile storage unit, and performs the cooling control on the device based on the estimated temperature T2 after the delay time t2 (S35 to S40).

[0114] In the power control device configured as described above in [1], since the control unit performs control based on the estimated temperature after a specific delay time t2 from a specific time point, the influence of the delay occurring in actual temperature control can be reduced, and temperature control with high precision can be achieved. In addition, since information indicating the unique characteristics of each device is obtained from the non-volatile storage unit, the control error caused by individual differences in the devices to be controlled can be reduced.

[0115] [2] In the power control device according to [1] above,

[0116] wherein the control unit determines a first temperature threshold Tth1 and a second temperature threshold Tth2 greater than the first temperature threshold Tth1, and calculates the estimated temperature T2 by adding the temperature rise value ΔT2 to the current temperature T1 (S36).

[0117] wherein, when the estimated temperature T2 is less than the first temperature threshold Tth1, the control unit suppresses the cooling performed by the cooling mechanism (S37).

[0118] wherein, when the estimated temperature T2 is equal to or greater than the first temperature threshold Tth1 and less than the second temperature threshold Tth2, the control unit promotes the cooling performed by the cooling mechanism (S39), and

[0119] wherein, when the estimated temperature T2 is equal to or greater than the second temperature threshold Tth2, the control unit suppresses the power supply to the heating component (S40).

[0120] In the power control device configured as described above in [2], appropriate control can be performed according to the actual temperature change of the device. That is, when the condition "T2 < Tth1" is satisfied, even if the cooling is suppressed, it is highly likely that the actual temperature after the delay time t2 from the current time will remain below the temperature threshold Tth2. In addition, when the condition "Tth1 ≤ T2 < Tth2" is satisfied, by promoting the cooling, it is highly likely that the actual temperature after the delay time t2 from the current time will remain below the temperature threshold Tth2. In addition, when the condition "T2 ≥ Tth2" is satisfied, control is performed not only by cooling but also by reducing the heat generation amount of the heating component, and abnormal rise of the actual temperature after the delay time t2 from the current time can be avoided.

[0121] [3] In the power control device according to [1] or [2] above,

[0122] wherein the control unit detects the temperature difference ΔT between two points at different positions (S12);

[0123] The control unit calculates the thermal resistance based on the detected temperature difference ΔT, and

[0124] The control unit stores the thermal resistance in the non-volatile memory unit (S19).

[0125] According to the power control device with the above [3] configuration, since the temperature difference ΔT obtained by actual measurement is used, the thermal resistance can be calculated with high accuracy under the condition that the influence of individual differences of the device can be compensated.

[0126] [4] A temperature control method for controlling the temperature of a device equipped with a cooling mechanism (cooling unit 17) and heat-generating components (semiconductor switching elements FET1, FET2) that are heated by energization, the temperature control method comprising:

[0127] In the pre-performed calibration process (see Figure 4 In the process, information indicating the unique characteristics of the thermal resistance (Rth) and thermal capacity (Cth) of the device for each current of the heating element is calculated and stored (S21);

[0128] The current I flowing through the heating element and the current temperature T1 (S31, S36) are obtained by measurement;

[0129] The temperature rise ΔT2 after a specific delay time t2 is estimated based on the stored thermal resistance and thermal capacity, and the acquired current I; and

[0130] The estimated temperature (T2) after the delay time t2 is reflected in the cooling control (S36 to S40).

[0131] [5] The temperature control method described in [4] above further includes:

[0132] The estimated temperature (T2) is calculated by adding the temperature rise (ΔT2) to the current temperature (T1);

[0133] If the estimated temperature (T2) is less than the first temperature threshold (Tth1), the cooling performed by the cooling mechanism is suppressed;

[0134] When the estimated temperature (T2) is equal to or greater than the first temperature threshold (Tth1) and less than the second temperature threshold (Tth2), cooling performed by the cooling mechanism is promoted; and

[0135] If the estimated temperature (T2) is equal to or greater than the second temperature threshold (Tth2), the power supply to the heating element is suppressed.

[0136] Wherein, the second temperature threshold (Tth2) is greater than the first temperature threshold (Tth1).

[0137] [6] According to the temperature control method described in [4] or [5] above, it also includes:

[0138] The temperature difference (ΔT) between two points at different locations is measured (S12).

[0139] The thermal resistance is calculated based on the detected temperature difference (ΔT); and

[0140] The thermal resistor is stored in a non-volatile memory cell (S19).

[0141] According to the temperature control method based on the process described above [4], since control can be performed based on the estimated temperature after a specific delay time t2 from a specific time point, the effects of delays occurring in actual temperature control can be reduced, and high-precision temperature control can be achieved. In addition, since information indicating the unique characteristics of each device is obtained in the calibration process, control errors caused by individual differences of the device to be controlled can be reduced.

Claims

1. A power control device for controlling the temperature of a device, wherein a cooling mechanism and a heating element that heats up when energized are mounted on the device, the power control device comprising: A non-volatile memory cell stores information representing specific characteristics, including the thermal resistance and thermal capacity of the device for each current of the heating element; A current measuring unit configured to measure the current flowing through the heating element; A temperature measuring unit configured to measure the current temperature of the heating element; as well as A control unit configured to perform cooling control on the device. The control unit estimates the temperature rise after a specific delay time from the measurement of the current temperature based on the current measured by the current measurement unit, the temperature measured by the temperature measurement unit, and information about the specific characteristics stored in the non-volatile storage unit. It calculates the estimated temperature by adding the temperature rise to the current temperature and performs the cooling control on the device based on the estimated temperature after the delay time.

2. The power control device according to claim 1, in, The control unit determines a first temperature threshold and a second temperature threshold that is greater than the first temperature threshold. Wherein, if the estimated temperature is less than the first temperature threshold, the control unit inhibits the cooling performed by the cooling mechanism. Wherein, if the estimated temperature is equal to or greater than the first temperature threshold and less than the second temperature threshold, the control unit facilitates cooling performed by the cooling mechanism, and Specifically, when the estimated temperature is equal to or greater than the second temperature threshold, the control unit suppresses the power supply to the heating element.

3. The power control device according to claim 1 or 2, in, The control unit detects the temperature difference between two points at different locations. The control unit calculates the thermal resistance based on the detected temperature difference, and The control unit stores the thermal resistance in the non-volatile memory unit.

4. A temperature control method for controlling the temperature of a device, wherein a cooling mechanism and a heating element that heats up when energized are mounted on the device, the temperature control method comprising: During the calibration process, information representing specific characteristics is calculated and stored, including the thermal resistance and thermal capacity of the device for each current of the heating element; The current temperature and the current flowing through the heating element are obtained by measurement; In the estimation process, the temperature rise after a specific delay time from the measurement of the current temperature is estimated based on the stored thermal resistance and thermal capacity and the obtained current. The estimated temperature is calculated by adding the temperature rise value to the current temperature; as well as Cooling control is performed based on the estimated temperature after the aforementioned delay time. The calibration process is performed before the estimation process.

5. The temperature control method according to claim 4 further includes: If the estimated temperature is less than a first temperature threshold, the cooling performed by the cooling mechanism is suppressed; When the estimated temperature is equal to or greater than the first temperature threshold and less than the second temperature threshold, cooling performed by the cooling mechanism is promoted. as well as When the estimated temperature is equal to or greater than the second temperature threshold, the power supply to the heating element is suppressed; Wherein, the second temperature threshold is greater than the first temperature threshold.

6. The temperature control method according to claim 4 or 5 further includes: The temperature difference between two points located at different points is detected. The thermal resistance is calculated based on the detected temperature difference; as well as The thermal resistance is stored in a non-volatile memory cell.

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