Electric machine

Abstract

To provide an electric machine that can reliably detect abnormal heat generation in an electric component regardless of a heat capacity of a heat transfer path from the electric component to a temperature detector or an ambient temperature of the electric component.SOLUTION: An electric machine A1 includes a functional unit 1 including an electric component 11, a control unit 4 that controls the electric component 11, and a protection unit 2 that detects a component temperature of the electric component 11 and performs a protection operation to suppress increase in the component temperature when the detected component temperature becomes equal to or higher than a preset protection temperature. The control unit 4 includes a normal operation unit 41 that normally operates the functional unit 1 in a standard state where an ambient temperature of the electric component 11 is equal to or higher than a discrimination temperature that is lower than the protection temperature, and a preheating unit 42 that increases the ambient temperature in a low temperature state where the ambient temperature of the electric component 11 is lower than the discrimination temperature.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to electrical devices. [Background technology]

[0002] Conventionally, electrical devices in which electrical components are arranged inside a housing are known. Patent Document 1 discloses an inverter device as an example of such electrical devices. The inverter device described in Patent Document 1 includes a die-cast case, a main body cover, and a surface cover. The die-cast case is equipped with a plurality of electrical components, such as a diode module constituting a forward conversion section, an intelligent power module constituting an inverse conversion section, a current detector for detecting the output current of the inverter, and an electrolytic capacitor for smoothing a DC voltage. These electrical components are surrounded by the die-cast case, the main body cover, and the surface cover.

[0003] Furthermore, methods for detecting temperature abnormalities in electrical components have been devised. For example, Patent Document 2 discloses a method for detecting temperature abnormalities in a component that needs to be protected from temperature abnormalities by attaching a thermostat to the component. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-303779 [Patent Document 2] JP 2008-104245 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above electric device, if a thermostat is attached to detect abnormal heat generation in an electric component as in Patent Document 2, the following phenomenon may occur. For example, if the heat capacity of the heat transfer path from the electric component to the thermostat is large and the ambient temperature of the electric component is low, it takes time for the temperature of the part where the thermostat is attached to rise in response to abnormal heat generation in the electric component. As a result, the temperature difference between the temperature detected by the thermostat and the temperature of the electric component increases over time, and there is a risk that the temperature of the electric component will reach its destruction temperature (the withstand temperature of the electric component) before the temperature detected by the thermostat reaches the operating temperature of the thermostat.

[0006] The present disclosure has been devised in consideration of the above-mentioned circumstances, and its purpose is to provide an electrical device that can reliably detect abnormal heat generation in an electrical component regardless of the heat capacity of the heat transfer path from the electrical component to the temperature detector or the ambient temperature of the electrical component. [Means for solving the problem]

[0007] The electrical device provided by the present disclosure comprises a functional unit including an electrical component, a control unit that controls the electrical component, and a protection unit that detects a component temperature of the electrical component and performs a protective operation to suppress an increase in the component temperature when the detected component temperature becomes equal to or higher than a predetermined protection temperature, wherein the control unit includes a normal operation unit that operates the functional unit normally in a standard state in which the ambient temperature of the electrical component is equal to or higher than a discrimination temperature that is lower than the protection temperature, and a pre-heating unit that increases the ambient temperature in a low temperature state in which the ambient temperature is lower than the discrimination temperature.

[0008] In a preferred embodiment of the electrical equipment, the normal operation unit controls the electrical components so that, in the standard state, the output of the functional unit is a first output, and the preheating unit controls the electrical components so that, in the low temperature state, the output of the functional unit is a second output smaller than the first output.

[0009] In a preferred embodiment of the electric device, the preheating section includes a heater for increasing an ambient temperature of the electric component, and the heater is operated in the low temperature state.

[0010] In a preferred embodiment of the electrical device, the electrical device further comprises a detection unit that detects the ambient temperature.

[0011] In a preferred embodiment of the electrical device, when starting up the functional unit, the control unit continues the process of raising the ambient temperature using the preheating unit for a predetermined period of time, and then causes the functional unit to operate normally using the normal operation unit.

[0012] In a preferred embodiment of the electrical device, the functional unit is a power conversion unit that converts an input first power into a second power and outputs it, the electrical component includes at least one switching element, and the control unit controls the electrical component by outputting a drive signal to the at least one switching element. Effect of the Invention

[0013] In the electric device of the present disclosure, when the ambient temperature (detection value) is below the discrimination temperature and is in a low temperature state, such as when the electric device is started, the preheating unit raises the ambient temperature of the electric component, and when the ambient temperature (detection value) is equal to or higher than the discrimination temperature, the functional unit operates normally. In other words, the electric device of the present disclosure raises the ambient temperature of the electric component moderately and then operates the functional unit normally. With this configuration, the component temperature detected by the protection unit (including, for example, a thermostat) reaches the protection temperature (the temperature at which the protection unit performs a protection operation) before the temperature difference between the component temperature detected by the protection unit and the actual component temperature of the electric component becomes excessively large. In other words, it is possible to prevent the actual component temperature of the electric component from reaching the destruction temperature. Therefore, the electric device of the present disclosure can reliably detect abnormal heat generation of the electric component regardless of the heat capacity of the heat transfer path from the electric component to the protection unit or the ambient temperature of the electric component. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic diagram showing a component layout of the electrical device according to the first embodiment. [Diagram 2] FIG. 2 is a functional block diagram of the electrical device according to the first embodiment. [Diagram 3] 5A to 5C are diagrams illustrating examples of the operation of the electric device according to the first embodiment and a comparative electric device. [Figure 4] FIG. 11 is a schematic diagram showing a component layout of an electrical device according to a second embodiment. [Diagram 5] FIG. 11 is a functional block diagram of an electrical device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the electrical device of the present disclosure will now be described with reference to the drawings. In the following, identical or similar components are designated by the same reference numerals and redundant description will be omitted.

[0016] 1 and 2 show an electric device A1 according to a first embodiment. Fig. 1 is a schematic diagram showing a component layout of the electric device A1. Fig. 2 is a functional block diagram of the electric device A1. The electric device A1 of this embodiment is a power conversion device that converts an input first power into a second power and outputs the second power, and specifically, is a converter device that converts DC power or AC power into DC power, or an inverter device that converts AC power or DC power into AC power.

[0017] The electric device A1 includes a functional unit 1, a protective unit 2, a detecting unit 3, and a control unit 4. As shown in FIG. 1, the functional unit 1, the protective unit 2, the detecting unit 3, and the control unit 4 are housed in a housing 90 of the electric device A1. In addition to these, a heat sink 91 is housed in the housing 90 of the electric device A1. In this disclosure, the housing of a certain component includes not only the case where the entire component is housed, but also the case where a part of the component is housed, unless otherwise specified. A cooling device 92 is attached to the heat sink 91. The cooling device 92 cools each component in the electric device A1. The cooling device 92 has, for example, a fan, and releases heat transferred to the heat sink 91 to the outside by operating the fan. The cooling device 92 may be partly housed in the housing 90, or may be disposed outside the housing 90.

[0018] The functional unit 1 is a central part of the electric device A1. The functional unit 1 is controlled by the control unit 4, and in one example, is a power conversion unit that converts an input first power into a second power and outputs it. The relative magnitude relationship between the first power and the second power, and whether the first power and the second power are AC power or DC power, may be any combination. Note that the functional unit 1 is not limited to a power conversion unit. The functional unit 1 includes an electric component 11.

[0019] The electric component 11 includes at least one switching element (e.g., a MOSFET, an IGBT, or a bipolar transistor). In this embodiment, the electric component 11 is a semiconductor device in which a plurality of switching elements are full-bridge connected. In this example, the electric component 11 converts input DC power (first power) into AC power (second power) by switching on and off the plurality of switching elements by a drive signal input from the control unit 4. The electric component 11 is, for example, a component that functions as an inverter circuit, and in this example, the functional unit 1 is a switching regulator. Note that the configuration of the electric component 11 is not limited to the above example. Unlike this example, the electric component 11 may be a semiconductor device in which a plurality of switching elements are half-bridge connected, or may be a semiconductor device composed of one switching element. For example, the electric component 11 may include other active elements such as diodes and relays, or passive elements such as resistors, capacitors, reactors, and transformers, instead of or in addition to the switching elements.

[0020] 1, the electric component 11 is attached to a heat sink 91 in a housing 90 of the electric device A1. Thus, heat from the electric component 11 is transferred to the heat sink 91. Then, the heat is released to the outside via a cooling device 92. Unlike this example, the electric component 11 may be attached to a circuit board, and the heat sink 91 may be disposed so as to be in contact with the electric component 11.

[0021] The protection unit 2 detects the component temperature of the electric component 11. When the detected temperature becomes equal to or higher than a preset protection temperature, the protection unit 2 performs a protection operation for the electric component 11. The protection unit 2 includes a thermostat 21. The thermostat 21 has a sensor for detecting temperature, and the sensor detects the temperature at the installation position as the component temperature of the electric component 11. The sensor may be a mechanical detection sensor using a bimetal or a shape memory alloy, or an electrical detection sensor using a thermistor, a resistance temperature detector, a thermocouple, or the like. When the detected component temperature becomes equal to or higher than the protection temperature, the thermostat 21 outputs a protection temperature reached signal to a protection function unit (not shown). Unlike this example, the thermostat 21 may output a protection temperature not reached signal while the detected component temperature is lower than the protection temperature. The thermostat 21 is disposed around the electric component 11 (for example, within 1 cm from the electric component 11). In addition, since the installation position of the thermostat 21 is slightly offset from the installation position of the electric component 11, the component temperature detected by the thermostat 21 is slightly offset from the actual component temperature of the electric component 11. In the following, the actual component temperature of the electric component 11 is referred to as the "actual component temperature", and the component temperature detected by the thermostat 21 is referred to as the "detected component temperature". In the example shown in FIG. 1, the thermostat 21 is attached to the heat sink 91, as is the electric component 11. The protection function unit includes, for example, a heat dissipation fan, and operates the heat dissipation fan when a protection temperature reached signal is input (or a protection temperature not reached signal is not input). This reduces the component temperature of the electric component 11 or keeps the component temperature of the electric component 11 near the protection temperature. Alternatively, the protection function unit may stop the operation of the electric component 11 when a protection temperature reached signal is input (or a protection temperature not reached signal is not input). With this configuration, the protection unit 2 suppresses an increase in the component temperature of the electric component 11, so that the component temperature of the electric component 11 does not exceed the destruction temperature (temperature resistance of the electric component 11) of the electric component 11. The specific value of the protection temperature is not limited in any way, but is set based on the destruction temperature of the electric component 11, and is, for example, 100° C. Note that the protection unit 2 may be a temperature sensor including a thermistor or a thermocouple, instead of the thermostat 21.In this case, the protection function unit may determine whether or not the component temperature of the electric component 11 is equal to or higher than the protection temperature based on the measurement value of the temperature sensor.

[0022] The detection unit 3 detects the ambient temperature of the electric component 11. The detection unit 3 is, for example, a thermostat. The detection unit 3 detects the temperature of the installation position as the ambient temperature, and when the detected ambient temperature becomes equal to or higher than a preset discrimination temperature, outputs a discrimination temperature reaching signal to the control unit 4. Unlike this example, the detection unit 3 may output a discrimination temperature not reaching signal while the detected ambient temperature is below the discrimination temperature. The detection unit 3 is disposed around the electric component 11, and the ambient temperature detected by the detection unit 3 is the ambient temperature of the area including the electric component 11. As shown in FIG. 1, the thermostat 21 is also disposed around the electric component 11, so the ambient temperature detected by the detection unit 3 is the ambient temperature of the area including not only the electric component 11 but also the thermostat 21. The detection unit 3 is attached to the heat sink 91, for example, in the same manner as the electric component 11 and the thermostat 21. In the example shown in FIG. 1, the detection unit 3 and the thermostat 21 are disposed at equal distances from the electric component 11. As a result, the ambient temperature detected by the detector 3 and the component temperature detected by the thermostat 21 (the component detected temperature of the electrical component 11) become approximately the same value. The specific value of the discrimination temperature is not limited in any way, but is, for example, 20°C.

[0023] The control unit 4 controls the functional unit 1 (electrical components 11). The control unit 4 is composed of, for example, a CPU (central processing unit) and a memory, and includes one or more ICs (integrated circuits). The control unit 4 includes a normal operation unit 41 and a preheating unit 42. In this embodiment, the normal operation unit 41 and the preheating unit 42 may be configured in a common IC, or may be configured in separate ICs.

[0024] The normal operation unit 41 normally operates the electric device A1 in a state where the ambient temperature of the electric component 11 is equal to or higher than the discrimination temperature (hereinafter referred to as the "standard state"). The determination of whether or not the state is the standard state is performed based on a discrimination temperature reached signal (or a discrimination temperature not reached signal) from the detection unit 3. That is, when the normal operation unit 41 receives a discrimination temperature reached signal (or does not receive a discrimination temperature not reached signal) from the detection unit 3, it determines that the state is the standard state and normally operates the electric device A1. The normal operation unit 41 controls the electric component 11 so that the output of the functional unit 1 becomes the first output in the standard state. For example, the normal operation unit 41 outputs a standard time drive signal to the electric component 11 to set the output of the functional unit 1 to the first output. The first output is not limited to any particular value, but may be, for example, a rated output. The operation performed by the normal operation unit 41 (the operation of setting the output of the functional unit 1 to the first output) is referred to as a "standard output operation".

[0025] The preheating unit 42 heats the electric component 11 in a state where the ambient temperature of the electric component 11 is lower than the discrimination temperature (hereinafter referred to as the "low temperature state"). The determination of whether or not the electric component 11 is in the low temperature state is performed based on the discrimination temperature reached signal (or the discrimination temperature not reached signal) from the detection unit 3. That is, when the discrimination temperature reached signal is not input from the detection unit 3 (or when the discrimination temperature not reached signal is input), the preheating unit 42 determines that the electric component 11 is in the low temperature state, and heats the electric component 11. In this embodiment, the preheating unit 42 controls the electric component 11 in the low temperature state so that the output of the functional unit 1 becomes the second output. For example, the preheating unit 42 outputs a low temperature drive signal to the electric component 11 to set the output of the functional unit 1 to the second output. The second output is smaller than the first output. For example, the second output is 10% to 30% of the first output, but is not limited to this example. The operation performed by the preheating unit 42 (the operation of setting the output of the functional unit 1 to the second output) is called a "low output operation". In this embodiment, since the electric component 11 generates heat when energized, the electric component 11 is operated at an output lower than the first output to warm up the electric component 11. The pre-heating unit 42 continues to warm up the electric component 11 while the electric component 11 is in a low-temperature state.

[0026] Next, an operation example of the electric device A1 will be described with reference to FIG. 3. FIG. 3(a) shows the changes in the actual part temperature (actual part temperature) L11 of the electric component 11 and the part temperature (detected part temperature) L12 detected by the thermostat 21 in the electric device to be compared, and FIG. 3(b) shows the changes in the actual part temperature (actual part temperature) L21 of the electric component 11 and the part temperature (detected part temperature) L22 detected by the thermostat 21 in the electric device A1. The electric device to be compared is configured not to perform low-power operation, and when the electric device to be compared is started, the output of the functional unit 1 is set to the first output. In each graph shown in FIG. 3, the horizontal axis is time and the vertical axis is temperature. In the operation example shown in FIG. 3, the cooling device 92 does not operate due to a malfunction or the like. Therefore, the actual part temperatures L11 and L21 of the electric component 11 rise over time when electricity is applied. 3, the ambient temperature of the electric component 11 is assumed to be less than the discrimination temperature when the electric device A1 and the comparative electric device are started (at time t0). As described above, in this embodiment, the ambient temperature detected by the detection unit 3 and the component detected temperature detected by the thermostat 21 are approximately the same value, so the ambient temperature of the electric component 11 changes in the same manner as the component detected temperatures L12 and L22 detected by the thermostat 21 (that is, in each of the operation examples shown in FIGS. 3(a) and 3(b), the ambient temperature of the electric component 11 overlaps with the component detected temperatures L12 and L22 detected by the thermostat 21).

[0027] In the electric device to be compared, as shown in FIG. 3(a), when the electric device to be compared is started at time t0, the functional unit 1 is operated with the first output. Therefore, the electric component 11 of the functional unit 1 is energized, and the actual component temperature L11 gradually rises over time. In addition, with the rise in the actual component temperature L11, the component detection temperature L12 detected by the thermostat 21 of the protection unit 2 also gradually rises over time. However, if the heat capacity of the heat transfer path from the electric component 11 to the thermostat 21 is large, as shown in FIG. 3(a), the rate of increase of the actual component temperature L11 of the electric component 11 becomes larger than the rate of increase of the component detection temperature L12 detected by the thermostat 21, and the temperature difference between the actual component temperature L11 and the component detection temperature L12 becomes larger over time. As a result, the actual component temperature L11 reaches the destruction temperature at time t11 before the component detection temperature L12 becomes equal to or higher than the protection temperature. That is, in a comparative electric device that does not perform low-power operation, there is a risk that electric component 11 will be destroyed before the protective function of protector 2 operates.

[0028] On the other hand, as shown in FIG. 3(b), in the electric device A1, when the electric device A1 is started (at time t0), the ambient temperature is less than the discrimination temperature, so the preheating unit 42 (control unit 4) determines that the electric device A1 is in a low temperature state and operates the functional unit 1 at the second output. As a result, the electric component 11 is energized, and the electric component 11 generates heat, and the actual component temperature L21 rises. Then, the ambient temperature and the detected component temperature L22 rise with the rise in the actual component temperature L21. At this time, the actual component temperature L21 and the detected component temperature L22 rise at approximately the same rate of increase (note that in this embodiment, the ambient temperature is increased by the heat generated by the electric component 11, so strictly speaking, the rate of increase of the actual component temperature L21 is slightly greater than the rate of increase of the detected component temperature L22). After that, when the ambient temperature becomes equal to or higher than the discrimination temperature at time t21, the normal operation unit 41 (control unit 4) determines that the electric device A1 is in a standard state and operates the functional unit 1 at the first output. When the functional unit 1 switches from operating at the second output to operating at the first output, the load on the electric component 11 increases (for example, the current flowing therethrough increases), and the rate of increase of the actual component temperature L21 becomes higher than during operation at the second output (the period from time t0 to time t21). On the other hand, the detected component temperature L22 detected by the thermostat 21 also increases over time, but the rate of increase is smaller than the rate of increase of the actual component temperature L21. Therefore, after time t21, the temperature difference between the actual component temperature L21 and the detected component temperature L22 increases over time. After that, at time t22, the detected component temperature L22 becomes equal to or higher than the protection temperature, but at this time t22, the actual component temperature L21 has not yet reached the destruction temperature. In other words, the protection function by the protection unit 2 operates before the actual component temperature L21 reaches the destruction temperature. As a result, destruction of the electric component 11 is suppressed in the electric device A1.

[0029] The functions and effects of the electric device A1 are as follows.

[0030] In the electric device A1, when the ambient temperature of the electric component 11 is lower than a preset discrimination temperature, the preheating unit 42 heats the electric component 11. In this embodiment, the preheating unit 42 heats the electric component 11 by operating the electric component 11 so that the output of the functional unit 1 becomes the second output. As can be seen from FIG. 3(a), in the case where the preheating unit 42 is not provided (in the case of the comparative electric device), when the actual component temperature of the electric component 11 rises due to a failure of the cooling device 92 or the like, the temperature difference between the actual component temperature of the electric component 11 and the component detection temperature of the thermostat 21 becomes too large, and the actual component temperature of the electric component 11 exceeds the destruction temperature before the protective operation by the protective unit 2 is activated. In contrast, in the electric device A1, as can be seen from FIG. 3(b), the preheating unit 42 is provided, and the functional unit 1 starts normal operation (operation at the first output) after the ambient temperature of the electric component 11 becomes equal to or higher than the discrimination temperature. As a result, even if the actual component temperature of the electric component 11 rises due to a failure of the cooling device 92 or the like, the protection unit 2 activates a protective operation before the temperature difference between the actual component temperature of the electric component 11 and the component detected temperature of the thermostat 21 becomes large. In other words, the protection unit 2 activates a protective operation before the actual component temperature of the electric component 11 exceeds the destruction temperature, thereby preventing destruction of the electric component 11. Therefore, the electric device A1 can reliably detect abnormal heat generation of the electric component 11 even if the heat capacity of the heat transfer path from the electric component 11 to the thermostat 21 is large or the ambient temperature at startup is low.

[0031] In the electric device A1, the functional unit 1 is operated at the second output to warm the electric component 11. This allows the ambient temperature of the electric component 11 to be moderately warmed before the functional unit 1 is operated at the standard output (before it is operated at the first output). Furthermore, when the functional unit 1 is operated at the second output, the rate of increase in the actual component temperature in a low temperature state can be made smaller than when it is operated at the first output. Therefore, in the electric device A1, while the functional unit 1 is operated at the second output, the actual component temperature of the electric component 11 increases slowly, so that even if the heat capacity of the heat transfer path from the electric component 11 to the thermostat 21 is large, the temperature difference between the actual component temperature and the ambient temperature can be prevented from becoming large.

[0032] In the electric device A1, the protection unit 2 uses the thermostat 21 to determine whether the component temperature (component detection temperature) of the electric component 11 detected is equal to or higher than the protection temperature. As described above, the protection unit 2 may include a temperature sensor including a thermistor or a thermocouple instead of the thermostat 21. However, when configured with the thermostat 21, the component cost can be reduced compared to when configured with a temperature sensor or the like. Therefore, by using the thermostat 21 for temperature detection by the protection unit 2, the electric device A1 can reduce an increase in the cost of the electric device A1.

[0033] 4 and 5 show an electric device A2 according to a second embodiment. Fig. 4 is a schematic diagram showing a component layout of the electric device A2. Fig. 5 is a functional block diagram of the electric device A2. The electric device A2 is different from the electric device A1 in the configuration of the preheating unit 42.

[0034] As shown in FIG. 4 and FIG. 5, the preheating unit 42 of the electric device A2 includes a heater 421. As shown in FIG. 4, the heater 421 is housed in the housing 90. Unlike this example, the heater 421 may be disposed outside the housing 90. When the preheating unit 42 of the electric device A2 determines that the electric device A2 is in a low temperature state, the heater 421 is operated. This increases the ambient temperature of the electric component 11. Thereafter, when the ambient temperature becomes equal to or higher than the discrimination temperature, the preheating unit 42 stops the operation of the heater 421, and the normal operation unit 41 controls the electric component 11 so that the output of the electric device A2 becomes the first output (performs a standard output operation). The arrangement of the heater 421 is not limited as long as it can increase the ambient temperature of the electric component 11. In the example shown in FIG. 4, the heater 421 is disposed on the opposite side of the thermostat 21 and the detection unit 3 across the electric component 11. Unlike this example, the heater 421 may be arranged on the same side of the electrical component 11 as the thermostat 21 and the detection unit 3, or may be arranged on the opposite side of the electrical component 11 from the control unit 4.

[0035] The functions and effects of the electric device A2 are as follows.

[0036] In the electric device A2, similarly to the electric device A1, when the ambient temperature of the electric component 11 is lower than a preset discrimination temperature, the preheating unit 42 heats the electric component 11. Unlike the electric device A1, the preheating unit 42 in the electric device A2 heats the electric component 11 by operating the heater 421 in a low temperature state. Therefore, similarly to the electric device A1, the electric device A2 can reliably detect abnormal heat generation in the electric component 11 even when the heat capacity of the heat transfer path from the electric component 11 to the thermostat 21 is large or when the ambient temperature at the time of startup is low.

[0037] In the electric device A2, the preheating unit 42 includes a heater 421, and in a low temperature state, the heater 421 is operated to raise the ambient temperature of the electric component 11. This allows the ambient temperature to be raised appropriately before the functional unit 1 is operated at the standard output (before being operated at the first output).

[0038] In the first and second embodiments, an example in which the functional unit 1 includes one electric component 11 has been described. Unlike this example, the functional unit 1 may include multiple electric components 11. For example, when the electric device of the present disclosure is an inverter device that converts commercial AC power into desired AC power, the functional unit 1 may include electric components 11 that configure a rectifier circuit and electric components 11 that configure an inverter circuit, and the input commercial AC power may be rectified by the rectifier circuit, converted into DC power, and then converted into the desired AC power by the inverter circuit. Furthermore, an electric component 11 that configures a smoothing circuit may be provided between the rectifier circuit and the inverter circuit. In a configuration in which the functional unit 1 includes multiple electric components 11, the protection unit 2 and the detection unit 3 may be provided for the electric component 11 that generates a large amount of heat among the multiple electric components 11. In addition, when switching between the first output and the second output as in the electric device A1, the protection unit 2 and the detection unit 3 may be provided for the electric component 11 that can be controlled by the control unit 4 (for example, the one that configures the inverter circuit) among the multiple electric components 11.

[0039] In the first and second embodiments, the detection unit 3 is configured with a thermostat, and outputs a discrimination temperature reaching signal when the detected ambient temperature becomes equal to or higher than a preset discrimination temperature. Unlike this example, the detection unit 3 may simply be a temperature sensor that measures the ambient temperature. The temperature sensor includes, for example, a thermistor or a thermocouple. In this modified example, the detection unit 3 outputs the measurement value of the ambient temperature to the control unit 4. Then, the control unit 4 (each of the normal operation unit 41 and the preheating unit 42) can determine whether the state is standard or low temperature depending on whether the inputted measurement value of the ambient temperature is equal to or higher than the discrimination temperature or lower.

[0040] In the first and second embodiments, an example has been shown in which the temperature detection of the protection unit 2 and the temperature detection of the detection unit 3 are performed separately. Unlike this example, the temperature detection of the protection unit 2 and the temperature detection of the detection unit 3 may be performed by a common temperature sensor. In this case, the protection function unit of the protection unit 2 determines whether or not the temperature is equal to or higher than the protection temperature from the detection value of the common temperature sensor, while the control unit 4 (the normal operation unit 41 and the preheating unit 42) determines whether or not the temperature is equal to or higher than the discrimination temperature (whether the temperature is in a standard state or a low temperature state) from the detection value of the common temperature sensor.

[0041] In the first and second embodiments, an example in which the detection unit 3 detects the ambient temperature of the electric component 11 is described. Unlike this example, the electric device of the present disclosure may be sequentially controlled so that, after start-up, the functional unit 1 is first operated at the second output (low output operation) (or the heater 421 is operated), and then, after a predetermined time has elapsed, the functional unit 1 is operated at the first output (standard output operation) (or the heater 421 is stopped). For example, the predetermined time is set based on the time from when the functional unit 1 is operated at the low output or when the heater 421 is operated until the ambient temperature reaches or exceeds the discrimination temperature. In such an example, the electric device of the present disclosure may not include the detection unit 3.

[0042] The electric device according to the present disclosure is not limited to the above-described embodiment. The specific configuration of each part of the electric device according to the present disclosure can be freely designed in various ways. [Explanation of symbols]

[0043] A1, A2: Electrical equipment, 1: Functional part, 2: Protection part, 3: Detection part, 4: Control part, 11: Electrical part, 41: Normal operation part, 42: Preheating part, 421: Heater

Claims

1. A functional unit including an electrical component; A control unit that controls the electrical components; a protection unit that detects a component temperature of the electrical component, and when the detected component temperature becomes equal to or higher than a preset protection temperature, performs a protection operation to suppress an increase in the component temperature; Equipped with The control unit includes a normal operation unit that operates the functional unit normally in a standard state where the ambient temperature of the electrical component is equal to or higher than a discrimination temperature that is lower than the protection temperature, and a preheating unit that raises the ambient temperature in a low temperature state where the ambient temperature is lower than the discrimination temperature.

2. the normal operation unit controls the electrical components so that an output of the functional unit becomes a first output in the standard state; The electrical device according to claim 1 , wherein the preheating unit controls the electrical components such that, in the low temperature state, an output of the functional unit becomes a second output that is smaller than the first output.

3. The electrical device according to claim 1 , wherein the preheating section includes a heater that increases an ambient temperature of the electrical component, and the heater is operated in the low temperature state.

4. The electrical device according to claim 1 , further comprising a detection unit that detects the ambient temperature.

5. The electrical device according to claim 1 , wherein the control unit, when activating the functional unit, continues a process of increasing the ambient temperature by the preheating unit for a predetermined period of time, and then causes the functional unit to operate normally by the normal operation unit.

6. the functional unit is a power conversion unit that converts an input first power into a second power and outputs the second power, the electrical component includes at least one switching element; The electrical device according to claim 1 , wherein the control unit controls the electrical component by outputting a drive signal to the at least one switching element.

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