Electromagnetic heating control system and air conditioner

Abstract

The application discloses an electromagnetic heating control system and an air conditioner. The electromagnetic heating control system comprises a power module, an outdoor fan and a control module. The control module performs the following: when the actual electromagnetic heating current reaches the fan opening threshold current, the outdoor fan is controlled to open; after the outdoor fan opens and under the current outdoor environment temperature, when the electromagnetic heating target current reaches the lower limit value of the preset current threshold, after the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan rotating speed of the outdoor fan is controlled to reach the fan target rotating speed corresponding to the electromagnetic heating target current; when the electromagnetic heating target current reaches the upper limit value of the preset current threshold, before the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan rotating speed of the outdoor fan is controlled to reach the fan target rotating speed corresponding to the electromagnetic heating target current. When the electromagnetic heating current is large, the power module is promptly cooled through the pre-speed-up mode of the outdoor fan.

Description

Technical Field

[0001] This invention relates to the field of compressor preheating technology, and more particularly to an electromagnetic heating control system and an air conditioner. Background Technology

[0002] In recent years, the demand for air conditioners has been expanding across various regions, especially in northern areas where air conditioners are used for heating in low winter temperatures. In an air conditioning system, the compressor acts as the power unit, and the viscosity of the refrigerant oil inside the compressor plays a crucial role in its reliability. When the outdoor unit is powered off and left stagnant for an extended period in low outdoor temperatures, due to the miscibility of the lubricating oil and refrigerant, a large amount of refrigerant will accumulate in the compressor crankcase. This leads to a decrease in lubricating oil concentration, failing to meet the compressor's lubrication requirements. Insufficient lubrication hinders the air conditioning system's startup, and the extremely low temperature of motor components at low temperatures can also cause unreliable starting.

[0003] To avoid damaging the compressor, it is necessary to preheat the compressor before starting it to ensure that the lubricating oil meets reliability requirements after the compressor starts.

[0004] Currently, the industry primarily uses two methods: auxiliary heating and electromagnetic heating. However, due to the high efficiency of electromagnetic heating, the method of controlling the compressor winding current for electromagnetic heating is widely adopted. Its main circuit topology is shown in [reference needed]. Figure 1 As shown, by controlling the power module to change the current output to the compressor winding, the heating power of the compressor winding and internal magnetic circuit is changed, thereby achieving the electromagnetic heating effect.

[0005] During electromagnetic heating, the power module also generates heat; therefore, power modules are typically equipped with a heat dissipation structure. (See [link to relevant documentation]). Figure 2 The outdoor fan speed is adjusted by a temperature sensor in the power module that detects the temperature of the power devices, in order to dissipate heat from the power module's heat sink.

[0006] However, due to factors such as noise, the noise level is altered by adjusting the carrier frequency. Therefore, the electromagnetic heating of the compressor uses a higher carrier frequency, resulting in greater switching losses in the power switching transistors within the power module. Consequently, the temperature (junction temperature) of the power devices inside the inverter rises rapidly with the electromagnetic heating current. However, the temperature sensor of the power devices, Tfin, rises slowly, with a delay compared to the rise of the internal junction temperature. This means that the temperature sensor cannot promptly reflect the rapid changes in the internal temperature of the power devices. Therefore, the outdoor fan speed adjusted based on this Tfin may not meet the requirements for timely heat dissipation of the power devices, leading to a risk of damage to the power devices.

[0007] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0008] To address the problems mentioned in the background art, the present invention provides an electromagnetic heating control system that drives the target speed of the outdoor fan by the outdoor ambient temperature and the target electromagnetic heating current. When the electromagnetic heating current is large, the power module is cooled in time by pre-increasing the speed of the outdoor fan, which prevents the internal temperature of the power device from rising sharply during the electromagnetic heating current rise of the compressor, thus preventing damage to the power module and improving the reliability of the power module.

[0009] To achieve the above-mentioned objectives, the present invention employs the following technical solution: Some embodiments of this application provide an electromagnetic heating control system, including: The compressor, located in the outdoor unit and driven by an electric motor, is used to compress low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas and discharge it to the condenser. A power module is used to invert the DC power supply from the bus to a three-phase voltage to power the motor. An ambient temperature detection element is used to detect the outdoor ambient temperature where the compressor is located; An outdoor fan, located in the outdoor unit, is driven to exchange airflow in the outdoor unit with outdoor ambient airflow. A control module is used to drive the power switching transistor in the power module to turn on / off during the preheating of the compressor, so as to electromagnetically heat the compressor. The control module is also used to determine the target fan speed of the outdoor fan based on both the outdoor ambient temperature and the target electromagnetic heating current, and executes the following: When the actual electromagnetic heating current reaches the fan start-up threshold current, the outdoor fan is controlled to start to dissipate heat from the power module. After the outdoor fan is turned on and under the current outdoor ambient temperature, when the electromagnetic heating target current reaches the lower limit of the preset current threshold, after the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current. When the electromagnetic heating target current reaches the upper limit of the preset current threshold, before the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current.

[0010] The electromagnetic heating control system involved in this application determines the target speed of the fan by taking into account the outdoor ambient temperature and the target electromagnetic heating current, which is beneficial for heat dissipation of the power module.

[0011] Furthermore, when the target current for electromagnetic heating is large, the outdoor fan speed is increased in advance to dissipate heat from the power module in a timely manner, thus avoiding damage to the power devices due to rapid changes in the internal temperature of the power module and improving the reliability of the power module.

[0012] In some embodiments of this application, considering the influence of outdoor ambient temperature and electromagnetic heating current on the heat generation of the power module, the target fan speed is determined based on the outdoor ambient temperature and the target electromagnetic heating current for effective heat dissipation of the power module. The electromagnetic heating control system further includes: The relationship module is used to establish the relationship between the outdoor ambient temperature, the target electromagnetic heating current, and the target fan speed of the outdoor fan. Under the same outdoor ambient temperature, different electromagnetic heating target currents correspond to different fan target speeds. The larger the electromagnetic heating target current, the larger the corresponding fan target speed. Under the same electromagnetic heating target current, different outdoor ambient temperatures correspond to different target fan speeds. The higher the outdoor ambient temperature, the higher the corresponding target fan speed.

[0013] In some embodiments of this application, the electromagnetic heating control system further includes: A heat sink is provided, and the power module is mounted on the heat sink.

[0014] The power module involved in this application has its heat sink mounted on it. By utilizing the large area of ​​the heat sink, the heat dissipation area of ​​the power module is increased, thereby improving the heat dissipation efficiency of the power module.

[0015] In some embodiments of this application, after the outdoor fan is turned on and under the current outdoor ambient temperature, as the electromagnetic heating target current gradually increases, the rate at which the actual electromagnetic heating current rises to the corresponding electromagnetic heating target current gradually decreases, while the rate at which the outdoor fan speed rises to the fan target speed corresponding to the corresponding electromagnetic heating target current gradually increases.

[0016] The electromagnetic heating control system involved in this application has a large rate of increase in actual electromagnetic heating current when the target electromagnetic heating current is small and increases, that is, it reaches the target electromagnetic heating current quickly, while the fan speed increases and the adjustment rate is slow.

[0017] When the target electromagnetic heating current is large and increases, the actual rate of increase of the electromagnetic heating current is small, that is, it reaches the target electromagnetic heating current more slowly. At the same time, the fan speed increases and the adjustment rate is faster, so as to quickly and effectively dissipate heat from the power module.

[0018] In some embodiments of this application, after the outdoor fan is turned on and under the current outdoor ambient temperature, as the electromagnetic heating target current gradually decreases, the rate at which the actual electromagnetic heating current decreases to the corresponding electromagnetic heating target current gradually increases, while the rate at which the outdoor fan speed decreases to the fan target speed corresponding to the corresponding electromagnetic heating target current gradually decreases.

[0019] The electromagnetic heating control system involved in this application has a large rate of decrease in the actual electromagnetic heating current when the target electromagnetic heating current decreases, that is, the target electromagnetic heating current is reached more quickly. At the same time, the fan speed decreases and the adjustment rate decreases. That is, while achieving effective heat dissipation of the power module, large-scale adjustment of the outdoor fan speed is avoided, and large heat dissipation fluctuations of the power module are avoided.

[0020] In some embodiments of this application, the electromagnetic heating control system further includes: A temperature sensing element, used to detect the module temperature of the power module; Under the current outdoor ambient temperature, when the actual electromagnetic heating current increases from the first electromagnetic heating target current to the second electromagnetic heating target current, and the fan speed of the outdoor fan increases from the first fan target speed to the second fan target speed, the control module is also used to perform the following: S1: Obtain the module temperature detected by the temperature detection element and proceed to S2; S2: Determine whether the module temperature is stable at a preset temperature threshold. If yes, maintain the current state; otherwise, proceed to S3. S3: Determine whether the module temperature is rising or falling. If the module temperature is rising, proceed to S4; if the module temperature is falling, proceed to S5. S4: Increase the current target speed of the wind turbine and return to S1; S5: Reduce the current target speed of the wind turbine and return to S1.

[0021] As described above, under the current outdoor ambient temperature, if the fan speed reaches the target fan speed and the electromagnetic heating current reaches the target electromagnetic heating current, but the power module temperature still rises, it indicates that the current outdoor fan speed cannot meet the heat dissipation requirements of the power module. In this case, the fan speed needs to be adaptively adjusted according to the power temperature to effectively dissipate heat from the power module.

[0022] In some embodiments of this application, increasing the current target speed of the wind turbine in S4 specifically involves: Increase the current target speed of the wind turbine to the target speed of the adjacent wind turbine at the maximum adjustment rate; Among them, the adjustment rate of the fan speed between different adjacent fan target speeds increases as the fan target speed increases.

[0023] When adjusting the target speed of the fan, this application adjusts the fan speed at the maximum adjustment rate to quickly dissipate heat from the power module, ensuring reliable heat dissipation of the power module and avoiding damage due to drastic temperature rise.

[0024] In some embodiments of this application, reducing the current target speed of the wind turbine in S5 specifically involves: Reduce the current target speed of the wind turbine to the target speed of the adjacent wind turbine at the minimum adjustment rate; Among them, the adjustment rate of the fan speed between different adjacent fan target speeds decreases as the fan target speed decreases.

[0025] When adjusting and reducing the target speed of the fan, this application adjusts the fan speed at the minimum adjustment rate to avoid large-scale adjustments to the outdoor fan speed and to prevent large heat dissipation fluctuations in the power module.

[0026] This application also relates to an air conditioner, comprising: The refrigerant circulation loop allows the refrigerant to circulate in the compressor, condenser, expansion valve, and evaporator. The compressor is located in the outdoor unit and is driven by a motor. It is used to compress low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas and discharge it to the condenser. A power module is used to invert the DC power supply from the bus to a three-phase voltage to power the motor. An ambient temperature detection element is used to detect the outdoor ambient temperature where the compressor is located; An outdoor fan, located in the outdoor unit, is driven to exchange airflow in the outdoor unit with outdoor ambient airflow. A control module is used to drive the power switching transistor in the power module to turn on / off during the preheating of the compressor, so as to electromagnetically heat the compressor. The control module is also used to determine the target fan speed of the outdoor fan based on both the outdoor ambient temperature and the target electromagnetic heating current, and executes the following: When the actual electromagnetic heating current reaches the fan start-up threshold current, the outdoor fan is controlled to start to dissipate heat from the power module. After the outdoor fan is turned on and under the current outdoor ambient temperature, when the electromagnetic heating target current reaches the lower limit of the preset current threshold, after the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current. When the electromagnetic heating target current reaches the upper limit of the preset current threshold, before the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current.

[0027] The air conditioner involved in this application, when the compressor is preheated by electromagnetic heating, increases the speed of the outdoor fan in advance when the target current of electromagnetic heating is large, so as to dissipate heat from the power module in time, avoid damage to the power devices due to rapid changes in the internal temperature of the power module, improve the working reliability of the power module, and thus improve the reliability of the air conditioner.

[0028] In some embodiments of this application, the control module is used to control the preheating of the compressor when the outdoor ambient temperature reaches below the preheating temperature threshold.

[0029] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic block diagram of an embodiment of an air conditioner; Figure 2 For the existing PSMS control main circuit topology Figure 3 The second topology for the existing PSMS control main circuit; Figure 4 The third type is the existing PSMS control main circuit topology. Figure 5 This is a lookup table of the target fan speed involved in the electromagnetic heating control system embodiments proposed in this application; Figure 6 This is a schematic diagram showing the increase of fan speed with electromagnetic heating current in an embodiment of the electromagnetic heating control system proposed in this application; Figure 7This is a flowchart illustrating the adjustment process between the fan speed adjustment rate and the electromagnetic heating current adjustment rate in the embodiment of the electromagnetic heating control system proposed in this application. Figure 8 This is a schematic diagram showing the arrangement of the power module and the outdoor fan in an embodiment of the electromagnetic heating control system proposed in this application; Figure 9 This is a schematic diagram illustrating how the fan speed adjusts with changes in module temperature in an embodiment of the electromagnetic heating control system proposed in this application. Figure 10 This is a flowchart illustrating how the fan speed adjusts with changes in module temperature in an embodiment of the electromagnetic heating control system proposed in this application. Figure label: 10. Compressor; 20. Power module; 30. Outdoor heat exchanger; 40. Indoor heat exchanger; 50. Outdoor fan; 60. Indoor fan; 70. Heat sink; A. Single-phase rectifier bridge; A1. Totem pole PFC circuit; A2. Three-phase rectifier bridge. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0038] Variable frequency control of motors (such as permanent magnet synchronous motors, PMSMs) is achieved by using a variable frequency topology circuit structure.

[0039] The compressor motor in an air conditioner is generally a PMSM. Therefore, the inverter topology circuit structure is widely used in air conditioners to adjust the frequency of the compressor motor in the air conditioner.

[0040] Basic operating principle of air conditioners See Figure 1 An air conditioner performs a refrigeration cycle by using a compressor 10, a condenser, a throttling element (such as an expansion valve), and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat an indoor space.

[0041] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0042] The expansion valve expands the high-temperature, high-pressure liquid refrigerant that condenses in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the expanded refrigerant in the expansion valve and returns the low-temperature, low-pressure refrigerant gas to the compressor 10. The evaporator achieves a cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioner regulates the temperature of the indoor space.

[0043] The outdoor unit of an air conditioner refers to the part of the refrigeration cycle that includes the compressor 10 and the outdoor heat exchanger 30. The indoor unit of an air conditioner includes the indoor heat exchanger 40 and the indoor fan 60, and an expansion valve can be provided in either the indoor unit or the outdoor unit.

[0044] The indoor heat exchanger 40 and the outdoor heat exchanger 30 are used as condensers or evaporators. When the indoor heat exchanger 40 is used as a condenser, the air conditioner is used as a heater in heating mode; when the indoor heat exchanger 40 is used as an evaporator, the air conditioner is used as a cooler in cooling mode.

[0045] The outdoor unit of an air conditioner is usually called the outdoor unit, and the indoor unit is usually called the indoor unit.

[0046] Variable frequency topology circuit structure See Figures 2 to 4 It shows a variety of frequency conversion topology circuit structures.

[0047] Figure 2 The diagram shows a single-phase rectifier bridge A and a power module 20.

[0048] The single-phase rectifier bridge A is formed by connecting four rectifier diodes in series.

[0049] Power module 20 is a three-phase power inverter used to invert DC power to drive the PMSM.

[0050] The three-phase power inverter consists of six power switching elements: S1 for the upper arm of phase U, S2 for the upper arm of phase V, S3 for the upper arm of phase W, S4 for the lower arm of phase U, S5 for the lower arm of phase V, and S6 for the lower arm of phase W.

[0051] The structure and working principle of a three-phase power inverter are well known and will not be elaborated here.

[0052] An electrolytic capacitor E is provided between the front end of the power module 20 and the rear end of the single-phase rectifier bridge A.

[0053] Figure 3 The totem pole PFC circuit A1 and power module 20 are shown.

[0054] The totem pole PFC circuit A1 is a common circuit and will not be described in detail here.

[0055] Figure 3 The power module 20 and Figure 1 The power module 20 in the middle has the same structure.

[0056] Figure 4 The three-phase rectifier bridge A2 and power module 20 are shown.

[0057] The three-phase rectifier bridge A2 is a common circuit that connects six rectifier diodes together.

[0058] Figure 4 The power module 20 and Figure 1 The power module 20 in the middle has the same structure.

[0059] The above-described frequency converter topology circuit structure is only shown as an example, and the frequency converter topology circuit structure involved in this application is not limited to the above-mentioned types.

[0060] Combination Figures 2 to 4 As can be seen, the frequency converter topology circuit structure includes a rectifier unit and a power module 20.

[0061] The input terminal of the rectifier unit is connected to the AC power supply. The rectifier unit is used to rectify the AC power supplied by the AC power supply to obtain rectified DC power.

[0062] Power module 20 receives rectified DC power and inverts it into three-phase AC power for use by PMSM.

[0063] Variable frequency topology circuits are mostly used in air conditioner outdoor units. The mainstream control algorithm for the motor of the compressor 10 in the air conditioner outdoor unit is field-oriented control (FOC), also known as vector control.

[0064] FOC control is a conventional technique in motor control, and will not be elaborated upon here.

[0065] Under low ambient temperature conditions, before the motor is started using FOC control, the compressor 10 needs to be preheated to ensure that the compressor 10 in the outdoor unit of the air conditioner starts normally and improve the starting reliability of the compressor 10.

[0066] Electromagnetic heating control system Electromagnetic heating, as a highly efficient heating method, is used to start the compressor 10 in the outdoor unit of an air conditioner under low ambient temperature.

[0067] Since electromagnetic heating is an AC / DC heating method with good heating effect, it is often used for compressor preheating in existing methods. There are also many different electromagnetic heating control methods in the existing technology.

[0068] Since the focus of this application is not on how to control electromagnetic heating, the implementation of electromagnetic heating control will not be elaborated upon in this application.

[0069] This application is concerned with the control of the outdoor fan 50 during the electromagnetic heating control process, realizing heat dissipation control of the power module 20 temperature rise caused by electromagnetic heating, and ensuring the reliable use of the power module 20.

[0070] The electromagnetic heating control system involved in this application includes a compressor 10 and a power module 20, the specific details of which are referenced in conjunction with [other documents]. Figures 1 to 4 The part described.

[0071] The electromagnetic heating control system also includes an ambient temperature detection element (not shown) for detecting the outdoor ambient temperature Ta where the compressor 10 is located.

[0072] The ambient temperature detection element is used to detect the outdoor ambient temperature Ta, which helps determine whether preheating is required before the compressor 10 starts.

[0073] When the outdoor ambient temperature Ta is low and the compressor 10 has been shut down for a period of time, the compressor 10 needs to be preheated before it can be started.

[0074] The threshold value of the outdoor ambient temperature Ta that needs to be preheated can be determined based on the start of compressor 10; the specific threshold value is not given here.

[0075] The electromagnetic heating control system also includes an outdoor fan 50, which and the compressor 10 are both located inside the outdoor unit.

[0076] When the air conditioner is running, the outdoor fan 50 is turned on to exchange the airflow inside the outdoor unit with the airflow in the outdoor environment, and at the same time, the outdoor fan 50 discharges the heat generated by the heat-generating device inside the outdoor unit to the outdoor environment.

[0077] When the compressor 10 is preheating, the outdoor fan 50 is turned on. The main purpose is to dissipate heat from the power module 20 and ensure the reliable operation of the power module 20.

[0078] The electromagnetic heating control system also includes a control module (not shown) for turning on / off the power switching transistor in the power module 20 when the compressor 10 is preheating, based on the principle of electromagnetic heating.

[0079] The heat generated by the power module 20 depends mainly on two factors: the outdoor ambient temperature Ta and the electromagnetic heating target current Ieih*.

[0080] Therefore, the target fan speed Nref of the outdoor fan 50 is determined based on the outdoor ambient temperature Ta and the electromagnetic heating target current Ieih*.

[0081] Therefore, in some embodiments of this application, a relationship is established between the outdoor ambient temperature Ta and the electromagnetic heating target current Ieih* and the fan target speed Nref of the outdoor fan 50.

[0082] When the target electromagnetic heating current Ieih* is constant, the lower the outdoor ambient temperature Ta, the smaller the target fan speed Nref; the higher the outdoor ambient temperature Ta, the larger the target fan speed Nref.

[0083] When the outdoor ambient temperature Ta is constant, the smaller the electromagnetic heating target current Ieih*, the smaller the fan target speed Nref; the larger the electromagnetic heating target current Ieih*, the larger the fan target speed Nref.

[0084] Based on this principle, the relationship between the outdoor ambient temperature Ta and the electromagnetic heating target current Ieih* is preset and the target fan speed Nref of the outdoor fan 50 is determined.

[0085] This relationship can be pre-written in a preset data table or as multiple commands, where each command describes the relationship between the outdoor ambient temperature Ta and the electromagnetic heating target current Ieih* and the target fan speed Nref of the outdoor fan 50.

[0086] The values ​​of the electromagnetic heating target current Ieih* and the outdoor ambient temperature Ta can be set as needed.

[0087] The outdoor ambient temperature Ta needs to be obtained through an ambient temperature sensing element, and it changes slowly.

[0088] The electromagnetic heating target current Ieih* is preset. The larger the electromagnetic heating target current Ieih*, the greater the heat generated by the motor winding of compressor 10, and vice versa.

[0089] In some embodiments of this application, four different outdoor ambient temperatures Ta and four different electromagnetic heating target currents Ieih* are used as examples for illustration.

[0090] The four outdoor ambient temperatures Ta are denoted as Ta1, Ta2, Ta3, and Ta4, where Ta1 is... <Ta2<Ta3<Ta4。

[0091] The four electromagnetic heating target currents Ieih* are denoted as: Ieih1*, Ieih2*, Ieih3*, and Ieih4*, where Ieih1*... <Ieih2*<Ieih3*<Ieih4*。

[0092] Thus, under different combinations of outdoor ambient temperature Ta and different electromagnetic heating target current Ieih*, 16 corresponding cases can be formed.

[0093] At an outdoor ambient temperature Ta1, the target wind turbine speeds Nref corresponding to Ieih1*, Ieih2*, Ieih3*, and Ieih4* are Nref11, Nref12, Nref13, and Nref14, respectively, and Nref11 <Nref12<Nref13<Nref14。

[0094] At an outdoor ambient temperature Ta2, the target wind turbine speeds Nref corresponding to Ieih1*, Ieih2*, Ieih3*, and Ieih4* are Nref21, Nref22, Nref23, and Nref24, respectively, and Nref21 <Nref22<Nref23<Nref24。

[0095] At an outdoor ambient temperature Ta3, the target wind turbine speeds Nref corresponding to Ieih1*, Ieih2*, Ieih3*, and Ieih4* are Nref31, Nref32, Nref33, and Nref34, respectively, and Nref31 <Nref32<Nref33<Nref34。

[0096] At an outdoor ambient temperature Ta4, the target wind turbine speeds Nref corresponding to Ieih1*, Ieih2*, Ieih3*, and Ieih4* are Nref41, Nref42, Nref43, and Nref44, respectively, and Nref41 <Nref42<Nref43<Nref44。

[0097] Under the electromagnetic heating target current Ieih1*, the target fan speeds Nref corresponding to Ta1, Ta2, Ta3 and Ta4 are Nref11, Nref21, Nref31 and Nref41 respectively, and Nref11 <Nref21<Nref31<Nref41。

[0098] Under the electromagnetic heating target current Ieih2*, the target fan speeds Nref corresponding to Ta1, Ta2, Ta3, and Ta4 are Nref12, Nref22, Nref32, and Nref42, respectively, and Nref12 <Nref22<Nref32<Nref42。

[0099] Under the electromagnetic heating target current Ieih3*, the target fan speeds Nref corresponding to Ta1, Ta2, Ta3, and Ta4 are Nref13, Nref23, Nref33, and Nref43, respectively, and Nref13 <Nref23<Nref33<Nref43。

[0100] Under the electromagnetic heating target current Ieih4*, the target fan speeds Nref corresponding to Ta1, Ta2, Ta3, and Ta4 are Nref14, Nref24, Nref34, and Nref44, respectively, and Nref14 <Nref24<Nref34<Nref44。

[0101] Therefore, a preset data table is established based on the preset outdoor ambient temperature Ta, electromagnetic heating target current Ieih*, and fan target speed Nref.

[0102] The contents of this preset data table can be found here. Figure 5 .

[0103] The preset data table described above can be stored in a storage unit (not shown), which is connected to the control module.

[0104] When in use, the control module retrieves the data table from the storage unit and queries the data table based on both the outdoor ambient temperature Ta and the electromagnetic heating target current Ieih* to determine the target fan speed Nref.

[0105] The outdoor ambient temperature Ta and the electromagnetic heating target current Ieih* mentioned in the data table above are just examples.

[0106] As mentioned above, the power temperature Tfin of the power module 20 detected by the temperature sensing element rises slowly, with a delay relative to the rise of the internal junction temperature. Therefore, it cannot promptly reflect the rapid changes in the internal temperature of the power module 20. Thus, this application adopts a pre-speed-up method based on the fan target speed Nref in the data sheet to dissipate heat from the power module 20 in a timely manner.

[0107] Since the outdoor ambient temperature Ta changes slowly, the pre-speed-up method is mainly based on the electromagnetic heating target current Ieih*.

[0108] Initially, the outdoor fan 50 is not started. It only starts when the actual electromagnetic heating current Ieih reaches the fan start-up threshold current Ieih0*.

[0109] In some embodiments of this application, since the electromagnetic heating target current Ieih* is different, the control of the outdoor fan 50 is segmented according to the different electromagnetic heating target currents Ieih*.

[0110] When the target electromagnetic heating current Ieih* is small, the actual electromagnetic heating current Ieih increases at a relatively high rate, meaning that the actual electromagnetic heating current Ieih can reach the target electromagnetic heating current Ieih* more quickly. At the same time, the fan speed N of the outdoor fan 50 increases at a relatively slow rate. In this case, the fan speed N can reach the target fan speed Nref after the actual electromagnetic heating current Ieih* reaches the target electromagnetic heating current Ieih*.

[0111] When the target electromagnetic heating current Ieih* is large, the actual electromagnetic heating current Ieih increases at a slower rate, meaning the actual electromagnetic heating current Ieih reaches Ieih* more slowly. At the same time, the fan speed N of the outdoor fan 50 increases at a faster rate. In this case, the fan speed N can reach the target fan speed Nref before the actual electromagnetic heating current Ieih reaches the target electromagnetic heating current Ieih*.

[0112] Thus, when the electromagnetic heating target current Ieih* is large, the fan speed N will reach the corresponding electromagnetic heating target current Ieih* fan target speed Nref in advance, thereby increasing heat dissipation in advance and alleviating the rapid rise in internal temperature of the power module 20.

[0113] A preset current threshold can be set for the electromagnetic heating target current Ieih* to determine whether the electromagnetic heating target current Ieih* is too large or too small.

[0114] The preset current threshold mentioned here can be a preset current value or a preset current range.

[0115] In some embodiments of this application, examples are given under the current outdoor ambient temperature Tam (where m takes the values ​​1, 2, 3, and 4).

[0116] At an outdoor ambient temperature Tam, the target fan speeds Nref corresponding to the electromagnetic heating target currents Ieih1*, Ieih2*, Ieih3*, and Ieih4* are Nrefm1, Nrefm2, Nrefm3, and Nrefm4, respectively, where Nrefm1 <Nrefm2<Nrefm3<Nrefm4。

[0117] In some embodiments of this application, a lower limit value can be set for Ieih1* and Ieih2* not reaching the preset current threshold, and an upper limit value can be set for Ieih3* and Ieih4* reaching the preset current threshold.

[0118] For example, if the preset current value is I, then Ieih1*<Ieih2*<I or Ieih1*<Ieih2*≤I, Ieih4*>Ieih3*>I or Ieih4*>Ieih3*≥I.

[0119] See Figure 6 The diagram shows the change of fan speed N with electromagnetic heating current Ieih.

[0120] (1) At time ti0, the actual electromagnetic heating current Ieih reaches the fan start-up threshold current Ieih0*, and the outdoor fan 50 starts.

[0121] (2) When the actual electromagnetic heating current Ieih is less than the electromagnetic heating target current Ieih1* from Figure 6 As can be seen from this, when the actual electromagnetic heating current Ieih continues to increase from Ieih0*, the rate of increase of the electromagnetic heating current Ieih is relatively fast (the adjustment rate in this stage, i.e., the rate of increase, is denoted as Irate1), while the rate of increase of the fan speed N (the adjustment rate in this stage, i.e., the rate of increase, is denoted as Nrate1) is relatively slow.

[0122] Furthermore, the actual electromagnetic heating current Ieih reaches Ieih1* at time ti1, while the fan speed N only reaches the target fan speed Nrefm1 at time tn1 after time ti1.

[0123] (3) When the actual electromagnetic heating current Ieih is less than the electromagnetic heating target current Ieih2* When the actual electromagnetic heating current Ieih continues to increase from Ieih1*, the rate of increase of the electromagnetic heating current Ieih is faster (the adjustment rate in this stage, i.e., the rate of increase is denoted as Irate2), while the rate of increase of the fan speed N (the adjustment rate in this stage, i.e., the rate of increase is denoted as Nrate2) is slower.

[0124] Furthermore, the actual electromagnetic heating current Ieih reaches Ieih2* at time ti2, while the fan speed N only reaches the target fan speed Nrefm2 at time tn2 after time ti2.

[0125] (3) When the actual electromagnetic heating current Ieih is less than the electromagnetic heating target current Ieih3* When the actual electromagnetic heating current Ieih continues to increase from Ieih2*, the rate of increase of the electromagnetic heating current Ieih is relatively slow (the adjustment rate in this stage, i.e., the rate of increase, is denoted as Irate3), while the rate of increase of the fan speed N (the adjustment rate in this stage, i.e., the rate of increase, is denoted as Nrate3) is relatively fast.

[0126] The fan speed N reaches the target fan speed Nrefm3 before time ti3, and the actual electromagnetic heating current Ieih reaches Ieih3* at time ti3. In this way, the outdoor fan 50 can dissipate heat from the power module 20, which is heated by the increase in electromagnetic heating current Ieih, in advance.

[0127] (4) When the actual electromagnetic heating current Ieih is less than the electromagnetic heating target current Ieih4* When the actual electromagnetic heating current Ieih continues to increase from Ieih4*, the rate of increase of the electromagnetic heating current Ieih is relatively slow (the adjustment rate in this stage, i.e., the rate of increase, is denoted as Irate4), while the rate of increase of the fan speed N (the adjustment rate in this stage, i.e., the rate of increase, is denoted as Nrate4) is relatively fast.

[0128] The fan speed N reaches the target fan speed Nrefm4 ahead of time tn4, before time ti4. Then, at time ti4, the actual electromagnetic heating current Ieih reaches Ieih4*. In this way, the outdoor fan 50 can dissipate heat from the power module 20, which is heated by the increase in electromagnetic heating current Ieih, in advance.

[0129] Subsequently, at the target fan speed Nrefm4, the electromagnetic heating current Ieih remains at Ieih4*.

[0130] The adjustment rates of the electromagnetic heating current Ieih and the fan speed N under the above-mentioned multiple stages are as follows: I rate1>Irate2>Irate3>Irate4,Nrate1 <Nrate2<Nrate3<Nrate4。

[0131] That is, at different stages, as the target electromagnetic heating current Ieih* increases, the rate of increase of the actual electromagnetic heating current Ieih gradually decreases, while the rate of increase of the fan speed N gradually increases. (See [reference needed]). Figure 7 As shown.

[0132] Figure 6 This describes the situation where the actual electromagnetic heating current Ieih rises. Conversely, for the multiple stages where the actual electromagnetic heating current Ieih falls, the adjustment rate of the electromagnetic heating current Ieih and the adjustment rate of the fan speed N are opposite to those when the electromagnetic heating current Ieih rises.

[0133] That is, at different stages, as the target electromagnetic heating current Ieih* decreases, the rate of decrease of the actual electromagnetic heating current Ieih gradually increases, while the rate of decrease of the fan speed N gradually decreases. (See [reference]). Figure 7 As shown.

[0134] As the actual electromagnetic heating current Ieih gradually decreases, the fan speed N slows down to ensure reliable heat dissipation for the power module 20.

[0135] In some embodiments of this application, see Figure 8 The electromagnetic heating control system also includes a heat sink 70.

[0136] To improve the heat dissipation of the power module 20, the power module 20 is placed on the heat sink 70 to increase the heat exchange area between the power module 20 and the airflow, thereby quickly removing the heat generated by the power module 20 and achieving the purpose of rapid heat dissipation.

[0137] If the control described above is used, at a certain moment, see Figure 9 After the electromagnetic heating current Ieih rises from the first electromagnetic heating target current Ieihx* and reaches the second electromagnetic heating target current Ieihy*, and the corresponding fan speed N also rises from the first fan target speed Nrefx and reaches the second fan target speed Nrefy, if the module temperature Tfin of the power module 20 is detected to rise from Tfinx to Tfiny and still rises, then the fan speed N should be changed to adapt to heat dissipation of the power module 20.

[0138] Wherein, the first fan target speed Nrefx is the fan target speed corresponding to the first electromagnetic heating target current Ieihx* under the current outdoor ambient temperature.

[0139] The target speed of the second fan, Nrefy, is the target speed of the fan corresponding to the target electromagnetic heating current Ieihy* under the current outdoor ambient temperature.

[0140] refer to Figure 10 It shows a flowchart of adjusting the fan speed N when the module temperature Tfin is still rising, as described above.

[0141] S1: Obtain the module temperature Tfin detected by the temperature sensing element and proceed to S2.

[0142] The temperature sensing element is used to detect the module temperature Tfin of the power module 20.

[0143] S2: Determine whether the module temperature Tfin is stable at the preset temperature threshold. If yes, maintain the current state; otherwise, proceed to S3.

[0144] Combination Figure 6 As mentioned above, when the electromagnetic heating target current Ieih* is large, the fan target speed Nref is increased in advance to dissipate heat from the power module 20 in a timely manner.

[0145] To ensure the reliability of heat dissipation of the power module 20, after the pre-speed increase and the electromagnetic heating current Ieih reaches the corresponding electromagnetic heating target current Ieih*, heat dissipation control will be implemented based on the actual module temperature fed back by the power module 20. This achieves multiple measures to ensure reliable heat dissipation of the power module 20 and ensure its reliable operation.

[0146] When the electromagnetic heating current Ieih rises from the first electromagnetic heating target current Ieihx* and reaches the second electromagnetic heating target current Ieihy*, and the corresponding fan speed N also rises from the first fan target speed Nrefx and reaches the second fan target speed Nrefy, it is determined whether the current actual module temperature Tfin is stable at the preset temperature threshold.

[0147] The preset temperature threshold can be a single temperature value or a temperature range.

[0148] If the module temperature Tfin is stable at the preset temperature threshold, no action is needed; the current state can be maintained. That is, it is sufficient to maintain the control of the current fan speed (the target fan speed Nref is the second target fan speed Nrefy) and the electromagnetic heating current (the target electromagnetic heating current Ieih* is the second target electromagnetic heating current).

[0149] If the module temperature Tfin is not stable at the preset temperature threshold, it means that the module temperature Tfin is in the rising stage. The reason is that the electromagnetic heating current Ieih is in the rising stage, and the power module 20 must be in the heat generation rising stage. Therefore, the module temperature is in the rising stage.

[0150] S3: Determine whether the module temperature Tfin is rising or falling. If the module temperature Tfin is rising, proceed to S4; if the module temperature Tfin is falling, proceed to S5.

[0151] When the module temperature Tfin rises, the fan speed N needs to be adjusted to dissipate heat from the power module 20 in a timely manner.

[0152] When the module temperature Tfin drops, it is also necessary to adjust the fan speed N in time to dissipate heat from the power module 20 and reduce the fan energy consumption.

[0153] S4: Increase the current target speed of the wind turbine and return to S1.

[0154] When the module temperature Tfin rises, it is necessary to increase the target speed Nref of the fan, increase the heat exchange air flow of the outdoor fan 50 and the power module 20, and improve the heat dissipation efficiency of the power module 20.

[0155] After adjusting the target fan speed Nref, the module temperature Tfin will be obtained again.

[0156] In some embodiments of this application, as the module temperature Tfin rises, in order to dissipate heat from the power module 20 in a timely manner, the current target fan speed Nref is increased to the target speed of the adjacent fan, and the adjustment rate of the fan speed N is adjusted at the maximum adjustment rate to quickly increase the fan speed N.

[0157] As described above, for example, the target speed of the first fan is Nref11, the target speed of the second fan is Nref12, the target current of the first electromagnetic heating is Ieih1*, and the target current of the second electromagnetic heating is Ieih2*.

[0158] If Tfin increases, the target wind turbine speed Nref will be increased to Nref13 at the maximum adjustment rate Nrate4.

[0159] As described above, for example, the target speed of the first fan is Nref12, the target speed of the second fan is Nref13, the target current of the first electromagnetic heating is Ieih2*, and the target current of the second electromagnetic heating is Ieih3*.

[0160] If Tfin increases, the target wind turbine speed Nref will be increased to Nref14 at the maximum adjustment rate Nrate4.

[0161] S5: Reduce the current target speed of the wind turbine and return to S1.

[0162] When the module temperature Tfin decreases, the target fan speed Nref needs to be reduced in order to both dissipate heat from the power module 20 and reduce the energy consumption of the outdoor fan 50.

[0163] After adjusting the target fan speed Nref, the module temperature Tfin will be obtained again.

[0164] In some embodiments of this application, when the module temperature Tfin is decreasing (but still greater than the preset temperature threshold), the current target fan speed Nref is reduced to the adjacent target fan speed, and the adjustment rate of the fan speed N is adjusted at the minimum adjustment rate to slowly reduce the fan speed and avoid large-scale reduction of the fan speed affecting the heat dissipation of the power module 20.

[0165] In some embodiments of this application, for example, the target speed of the first fan is Nref11, the target speed of the second fan is Nref12, the target current of the first electromagnetic heating is Ieih1*, and the target current of the second electromagnetic heating is Ieih2*.

[0166] If the module temperature Tfin rises, the target fan speed Nref will be increased to Nref13 at the maximum adjustment rate Nrate4.

[0167] If the module temperature Tfin then drops, the target fan speed Nref will be reduced to Nref12 at the minimum adjustment rate Nrate1.

[0168] In some embodiments of this application, for example, the target speed of the first fan is Nref12, the target speed of the second fan is Nref13, the target current of the first electromagnetic heating is Ieih2*, and the target current of the second electromagnetic heating is Ieih3*.

[0169] If Tfin increases, the target wind turbine speed Nref will be increased to Nref14 at the maximum adjustment rate Nrate4.

[0170] If Tfin then decreases, the target wind turbine speed Nref will be reduced to Nref13 at the minimum adjustment rate Nrate1.

[0171] Based on the rise / fall of the module temperature Tfin, repeatedly adjust the target fan speed Nref until the module temperature Tfin stabilizes at the preset temperature threshold.

[0172] air conditioner This application also relates to an air conditioner, see [link to application]. Figure 1 The air conditioner uses the electromagnetic heating control system described above for preheating. After preheating is completed, the compressor 10 starts normally.

[0173] The air conditioner described above includes a refrigerant circulation loop (not shown), a compressor 10, an outdoor heat exchanger 30, an indoor heat exchanger 40, a four-way valve (not shown), and an electromagnetic heating control system as described above.

[0174] The refrigerant circulation loop allows the refrigerant to circulate in the compressor 10, condenser, expansion valve, and evaporator.

[0175] Of the outdoor heat exchanger 30 and the indoor heat exchanger 40, one functions as a condenser and the other as an evaporator.

[0176] The four-way valve is used to control the refrigerant flow direction in the refrigerant circulation loop so that the outdoor heat exchanger 30 and the indoor heat exchanger 40 can switch between condenser and evaporator.

[0177] The compressor 10 is driven by an electric motor and is used to compress low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas and discharge it to the condenser.

[0178] For example, let's take the heating cycle of an air conditioner as an example.

[0179] When the four-way valve is powered on, the compressor 10 compresses the low-temperature, low-pressure refrigerant into a high-temperature, high-pressure state. The refrigerant discharged from the compressor 10 passes through the four-way valve, the gas-side shut-off valve, and the piping into the indoor heat exchanger 40.

[0180] After heat exchange inside the indoor heat exchanger 40, the refrigerant condenses and releases heat, becoming a liquid refrigerant. Subsequently, the refrigerant passes through the indoor side throttling device, piping, and liquid side shut-off valve, and enters the throttling device to be throttled to a low temperature and low pressure gas-liquid two-phase state. The two-phase refrigerant enters the outdoor heat exchanger 30 to evaporate and absorb heat, becoming a gas.

[0181] The refrigerant from the outdoor heat exchanger 30 enters the gas-liquid separator through the four-way valve, and is finally drawn into the compressor 10 for compression, completing the heating cycle.

[0182] In the above heating cycle, the indoor heat exchanger is used as a condenser, and the outdoor heat exchanger is used as an evaporator.

[0183] The AC power generated by the frequency conversion topology circuit is used to drive the motor PMSM of compressor 10.

[0184] A preheating time (e.g., time T) can be set, and the period within the preheating time is called the preheating stage.

[0185] When the air conditioner needs to be preheated, electromagnetic heating is used to preheat it until the preheating time is reached, at which point the preheating stage is complete.

[0186] During the preheating period, the outdoor fan 50 is controlled by the electromagnetic heating control system described above.

[0187] After the preheating phase is completed, the motor is started using the conventional FOC control method.

[0188] When the outdoor ambient temperature is below the preset temperature threshold, the outdoor unit of the air conditioner is considered to be in a low ambient temperature condition.

[0189] Under low ambient temperature conditions, compressor 10 needs to be preheated before starting to ensure reliable startup; otherwise, preheating of compressor 10 is not required.

[0190] Thus, under low ambient temperature, the compressor 10 is preheated by electromagnetic heating, and the speed of the outdoor fan 50 is controlled by the electromagnetic heating control system as described above during the preheating period to dissipate heat from the power module 20 in a timely manner, ensuring the reliable operation of the power module 20 and thereby improving the reliability of the air conditioner.

[0191] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0192] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electromagnetic heating control system, characterized in that, include: The compressor, located in the outdoor unit and driven by an electric motor, is used to compress low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas and discharge it to the condenser. A power module is used to invert the DC power supply from the bus to a three-phase voltage to power the motor. An ambient temperature detection element is used to detect the outdoor ambient temperature where the compressor is located; An outdoor fan, located in the outdoor unit, is driven to exchange airflow in the outdoor unit with outdoor ambient airflow. A control module is used to drive the power switching transistor in the power module to turn on / off during the preheating of the compressor, so as to electromagnetically heat the compressor. The control module is also used to determine the target fan speed of the outdoor fan based on both the outdoor ambient temperature and the target electromagnetic heating current, and to execute the following: When the actual electromagnetic heating current reaches the fan start-up threshold current, the outdoor fan is controlled to start to dissipate heat from the power module. After the outdoor fan is turned on and under the current outdoor ambient temperature, when the electromagnetic heating target current reaches the lower limit of the preset current threshold, after the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current. When the electromagnetic heating target current reaches the upper limit of the preset current threshold, before the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current.

2. The electromagnetic heating control system according to claim 1, characterized in that, The electromagnetic heating control system also includes: The relationship module is used to establish the relationship between the outdoor ambient temperature, the target electromagnetic heating current, and the target fan speed of the outdoor fan. Under the same outdoor ambient temperature, different electromagnetic heating target currents correspond to different fan target speeds. The larger the electromagnetic heating target current, the larger the corresponding fan target speed. Under the same electromagnetic heating target current, different outdoor ambient temperatures correspond to different target fan speeds. The higher the outdoor ambient temperature, the higher the corresponding target fan speed.

3. The electromagnetic heating control system according to claim 1, characterized in that, The electromagnetic heating control system also includes: A heat sink is provided, and the power module is mounted on the heat sink.

4. The electromagnetic heating control system according to claim 1, characterized in that, After the outdoor fan is turned on and under the current outdoor ambient temperature, as the electromagnetic heating target current gradually increases, the rate at which the actual electromagnetic heating current rises to the corresponding electromagnetic heating target current gradually decreases, while the rate at which the outdoor fan speed rises to the fan target speed corresponding to the corresponding electromagnetic heating target current gradually increases.

5. The electromagnetic heating control system according to claim 1, characterized in that, After the outdoor fan is turned on and under the current outdoor ambient temperature, as the electromagnetic heating target current gradually decreases, the rate at which the actual electromagnetic heating current decreases to the corresponding electromagnetic heating target current gradually increases, while the rate at which the outdoor fan speed decreases to the fan target speed corresponding to the corresponding electromagnetic heating target current gradually decreases.

6. The electromagnetic heating control system according to claim 1, characterized in that, The electromagnetic heating control system also includes: A temperature sensing element, used to detect the module temperature of the power module; Under the current outdoor ambient temperature, when the actual electromagnetic heating current increases from the first electromagnetic heating target current to the second electromagnetic heating target current, and the fan speed of the outdoor fan increases from the first fan target speed to the second fan target speed, the control module is also used to perform the following: S1: Obtain the module temperature detected by the temperature detection element and proceed to S2; S2: Determine whether the module temperature is stable at a preset temperature threshold. If yes, maintain the current state; otherwise, proceed to S3. S3: Determine whether the module temperature is rising or falling. If the module temperature is rising, proceed to S4; if the module temperature is falling, proceed to S5. S4: Increase the current target speed of the wind turbine and return to S1; S5: Reduce the current target speed of the wind turbine and return to S1.

7. The electromagnetic heating control system according to claim 6, characterized in that, In S4, the current target speed of the wind turbine is increased, specifically as follows: Increase the current target speed of the wind turbine to the target speed of the adjacent wind turbine at the maximum adjustment rate; Among them, the adjustment rate of the fan speed between different adjacent fan target speeds increases as the fan target speed increases.

8. The electromagnetic heating control system according to claim 6 or 7, characterized in that, In S5, the current target speed of the wind turbine is reduced, specifically as follows: Reduce the current target speed of the wind turbine to the target speed of the adjacent wind turbine at the minimum adjustment rate; Among them, the adjustment rate of the fan speed between different adjacent fan target speeds decreases as the fan target speed decreases.

9. An air conditioner, characterized in that, include: The refrigerant circulation loop allows the refrigerant to circulate in the compressor, condenser, expansion valve, and evaporator. The compressor is located in the outdoor unit and is driven by a motor. It is used to compress low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas and discharge it to the condenser. A power module is used to invert the DC power supply from the bus to a three-phase voltage to power the motor. An ambient temperature detection element is used to detect the outdoor ambient temperature where the compressor is located; An outdoor fan, located in the outdoor unit, is driven to exchange airflow in the outdoor unit with outdoor ambient airflow. A control module is used to drive the power switching transistor in the power module to turn on / off during the preheating of the compressor, so as to electromagnetically heat the compressor. The control module is also used to determine the target fan speed of the outdoor fan based on both the outdoor ambient temperature and the target electromagnetic heating current, and to execute the following: When the actual electromagnetic heating current reaches the fan start-up threshold current, the outdoor fan is controlled to start to dissipate heat from the power module. After the outdoor fan is turned on and under the current outdoor ambient temperature, when the electromagnetic heating target current reaches the lower limit of the preset current threshold, after the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current. When the electromagnetic heating target current reaches the upper limit of the preset current threshold, before the actual electromagnetic heating current rises and reaches the electromagnetic heating target current, the fan speed of the outdoor fan is controlled to reach the fan target speed corresponding to the electromagnetic heating target current.

10. The air conditioner according to claim 9, characterized in that, The control module is used to control the preheating of the compressor when the outdoor ambient temperature reaches below the preheating temperature threshold.

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