Power control circuit, frequency conversion device and range hood

Abstract

The application discloses a power control circuit, a frequency conversion device and a range hood. The power control circuit comprises a first input unit and a second input unit; the output ends of the first input unit and the second input unit are connected with a motor; the first input unit is used for inputting an original driving voltage to the motor in a first mode; the second input unit is used for completing a boosting work and discharging to the motor to input a discharging voltage higher than the original driving voltage to the motor in a second mode; the original driving voltage and the discharging voltage have the same polarity. On the one hand, in different modes, two power modes can be provided for the motor through different outputs of the first and second input units in the power control circuit; on the other hand, in the second mode, the discharging voltage of the second input unit is higher than the original driving voltage after the boosting work is completed, so that the motor power is improved through the increase of the power supply voltage of the motor.

Description

Technical Field

[0001] This application generally relates to the field of equipment power control, and more particularly to a power control circuit, a frequency converter, and a smoke machine. Background Technology

[0002] Currently, variable frequency range hoods, which use variable frequency control technology to achieve stepless adjustment of speed and air volume, are widely used in different cooking environments to solve the problem of poor smoke extraction in kitchens.

[0003] In existing technologies, variable frequency range hoods typically employ field weakening control on the variable frequency motor to reduce the magnetic field strength of the stator windings in the variable frequency motor, thereby reducing the back electromotive force generated by the variable frequency motor, so that current can be continuously input to drive the speed increase.

[0004] However, the process of field weakening control for variable frequency motors can easily affect motor performance and shorten motor life. Utility Model Content

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a power control circuit, a frequency converter, and a smoke hood. In the power control circuit provided in this application, on the one hand, in different modes, the motor can be provided with two power modes through the different outputs of the first and second input units in the power control circuit; on the other hand, in the second mode, after the second input unit completes the boost operation, its discharge voltage is higher than the original drive voltage, thereby increasing the motor power by increasing the supply voltage to the motor.

[0006] In a first aspect, the present invention provides a power control circuit, characterized in that the power control circuit includes a first input unit and a second input unit; the output terminals of the first input unit and the second input unit are respectively connected to a motor;

[0007] The first input unit is used to input the original drive voltage to the motor in a first mode;

[0008] The second input unit is used, in the second mode, to perform a boost operation and discharge to the motor, so as to input a discharge voltage higher than the original drive voltage to the motor; the original drive voltage and the discharge voltage have the same polarity;

[0009] The original driving voltage is the voltage signal obtained after rectification and filtering of the voltage input from the external power supply to the power control circuit.

[0010] In one possible implementation, the second input unit includes: a first filtering module and a voltage boost control module.

[0011] The input terminal of the first filtering module is configured to receive the voltage signal input from the external power supply, so as to rectify and filter the voltage signal input from the external power supply.

[0012] The voltage boost control module is used to control the discharge voltage of the second input unit to be higher than the original driving voltage based on the comparison result between the output voltage of the power control circuit and the reference voltage.

[0013] In one possible implementation, the voltage boost control module includes a feedback submodule, a drive submodule, and an energy storage submodule. The input terminal of the energy storage submodule is connected to the output terminal of the filter module, the output terminal of the energy storage submodule is connected to the drive submodule, and the feedback submodule is connected to both the output terminal of the power control circuit and the drive submodule.

[0014] The feedback submodule is used to sample the voltage signal output by the power control circuit;

[0015] The drive submodule is used to boost the voltage of the energy storage submodule when the voltage signal output by the power control circuit is less than the reference voltage, and maintain the voltage within the corresponding voltage range after boosting.

[0016] In one possible implementation, the drive submodule includes: a driver and a switch, wherein the input terminal of the driver is connected to the feedback submodule, the output terminal of the driver is connected to a first terminal of the switch, the second terminal of the switch is connected to the energy storage submodule, and the third terminal of the switch is grounded;

[0017] The driver is used to input a first control signal to the first terminal of the switch when the voltage signal output by the power control circuit is less than the reference voltage, thereby connecting the second terminal and the third terminal of the switch to charge the energy storage submodule.

[0018] The driver is also used to input a second control signal to the first terminal of the switch when the voltage signal output by the power control circuit is greater than the reference voltage, thereby cutting off the second terminal and the third terminal of the switch and controlling the energy storage submodule to discharge to cause the discharge voltage to rise.

[0019] In one possible implementation, the energy storage submodule is a power factor correction inductor.

[0020] In one possible implementation, the first input unit includes: a second filter module and a reactor, wherein the output terminal of the second filter module is connected to the input terminal of the reactor;

[0021] The input terminal of the second filtering module is configured to receive the voltage signal input from the external power supply, and to input the original driving voltage to the motor through the output terminal of the reactor after rectifying and filtering the voltage signal input from the external power supply.

[0022] In one possible implementation, the power control circuit further includes switching devices.

[0023] The switching device is used to cause the power control circuit to enter the first mode when closed;

[0024] The switching device is also used to cause the power control circuit to enter the second mode when it is disconnected.

[0025] In one possible implementation, the power control circuit is further used for:

[0026] The system receives a first electronic switch control signal and, in response to the first electronic switch control signal, charges the energy storage submodule. The first electronic switch control signal is used to control the switch to be turned on.

[0027] The system receives a second electronic switch control signal and, in response to the second electronic switch control signal, controls the energy storage submodule to discharge, causing the discharge voltage to rise. The second electronic switch control signal is used to control the switch to turn off.

[0028] In a second aspect, a frequency converter is provided, which includes the power control circuit described in the first aspect. The frequency converter responds to a frequency conversion signal and adjusts the power supply voltage of the motor to adjust the speed of the motor.

[0029] Thirdly, a range hood is provided, which includes the frequency converter described in the second aspect, specifically used to execute the control program of the frequency converter according to the frequency converter control command.

[0030] Compared to existing field weakening control methods that can improve motor power but easily affect motor performance, the power control circuit, frequency converter, and range hood provided in this application embodiment can, on the one hand, provide different power supply voltages to the motor through the different outputs of the first and second input units in the power control circuit under different modes, thereby obtaining two power modes for the motor; on the other hand, in the second mode, after the second input unit completes the boost operation, its discharge voltage is higher than the original drive voltage, thereby improving the motor power by increasing the power supply voltage to the motor.

[0031] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0032] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0033] Figure 1 This is one of the schematic diagrams of the power control circuit 10 provided in the embodiments of this application;

[0034] Figure 2 This is a schematic diagram of the operation of the frequency converter 20 provided in the embodiments of this application;

[0035] Figure 3 This is a schematic flowchart of a power control method provided in an embodiment of this application;

[0036] Figure 4 This is a second schematic diagram of the power control circuit 10 provided in the embodiments of this application;

[0037] Figure 5 This is the third schematic diagram of the power control circuit 10 provided in the embodiments of this application;

[0038] Figure 6 This is the fourth schematic diagram of the power control circuit 10 provided in the embodiments of this application;

[0039] Figure 7 This is the fifth schematic diagram of the power control circuit 10 provided in the embodiments of this application;

[0040] Figures 8a-8b This is a schematic diagram of a process for the range hood 30 to generate a frequency conversion signal according to an embodiment of this application;

[0041] Figure 9 This is the sixth schematic diagram of the power control circuit 10 provided in the embodiments of this application;

[0042] In the above image:

[0043] 10-Power control circuit; 11-First input unit; 12-Second input unit; 20-Frequency converter; 111-Second filter module; 112-Reactor; 401-Rectifier bridge; 402-Filter capacitor; 121-First filter module; 122-Voltage boost control module; 501-Rectifier bridge; 502-Filter capacitor; 503-Feedback submodule; 504-Driver submodule; 505-Energy storage submodule; 601-Driver; 602-Switch; 701-Diode; 702-Current detector; 30-Smoke hood; 901-Rectifier module; 902-Inductor module; 9021-Switching device. Detailed Implementation

[0044] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the scope of the utility model. Furthermore, it should be noted that, for ease of description, only the parts relevant to the utility model are shown in the accompanying drawings.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the accompanying drawings and embodiments. Furthermore, the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The terms "first" and "second," etc., in the specification and claims of the embodiments of this application are used to distinguish different objects, not to describe a specific order of objects.

[0046] First, the terminology used in this application will be explained as follows:

[0047] (1) Brushless DC Motor (BLDC): The stator windings of the motor are supplied with phase-switched square wave (or trapezoidal wave) alternating current to drive the rotor through electronic commutation.

[0048] (2) Variable frequency drive board: Converts the input power frequency AC (or DC) into three-phase AC with adjustable frequency and voltage to drive the motor.

[0049] (3) Maximum air volume of the range hood: refers to the maximum volume of air that the range hood can discharge per minute under ideal, unobstructed conditions;

[0050] (4) Maximum static pressure of the range hood: refers to the maximum thrust or suction force that the range hood can generate when the exhaust pipe is completely blocked, so as to reflect the range hood's ability to resist external resistance; among them, the greater the maximum static pressure of the range hood, the stronger the range hood's ability to push open the pressure of the public flue and exhaust the oil fumes.

[0051] (5) Power factor: refers to the relationship between the effective power of a circuit and the total power consumption (apparent power), that is, the ratio of effective power to total power consumption (apparent power). It can be used to measure the degree of effective utilization of electricity. Specifically, the larger the power factor value, the higher the power utilization rate.

[0052] Currently, range hoods, also known as kitchen exhaust hoods, are kitchen appliances designed to purify the kitchen environment. They are typically installed above the stove to quickly remove and expel the exhaust fumes and harmful cooking fumes from the stove, reducing kitchen oil pollution and purifying the air. However, with the widespread distribution of high-rise buildings, the shared ventilation ducts within these buildings are becoming increasingly congested, resulting in poor smoke extraction performance for range hoods installed on lower floors. In response, users have begun to use inverter range hoods to improve smoke extraction efficiency.

[0053] For example, the variable frequency control technology used in the motor of a variable frequency range hood is usually brushless DC motor control (BLDC), which uses an electronic system to precisely manage current, voltage, and commutation timing to unleash the high performance of the brushless motor. Specifically, maximum airflow and maximum static pressure are important performance parameters of variable frequency range hoods, which can be used to determine the upper limit of the range hood's suction power and exhaust power for cooking fumes. The maximum airflow and maximum static pressure values ​​are usually determined based on the range hood's inverter board and motor.

[0054] If only the inverter board inside the range hood is replaced without replacing the internal motor, the maximum air volume and maximum static pressure of the range hood will usually remain unchanged. Based on this, existing technology uses intelligent adjustment of the current direction and weakening of the magnetic field strength inside the motor to make the motor speed exceed the rated range (i.e., field weakening control) in order to increase the maximum air volume and maximum static pressure.

[0055] However, the aforementioned field weakening control method is prone to problems such as increased current, reduced efficiency, motor overheating, and unstable speed. In severe cases, it may even damage the motor and affect its lifespan.

[0056] The back electromotive force (EMF) E of a motor is determined by the product of the motor's electrical frequency f, the winding coefficient K, the number of turns N, and the magnetic flux φ (i.e., E = 4.44 × f × K × N × φ). When the winding coefficient K, the number of turns N, and the magnetic flux φ are approximately constant, the back EMF E of the motor is positively correlated with the motor's electrical frequency f (i.e., E1 / E2 = f1 / f2). Since the motor's electrical frequency f is proportional to the motor's rotational speed n (for example, the formula for determining the electrical frequency f is f = np / 60, where p represents the number of pole pairs inside the motor, and f1 / f2 = n1 / n2), the higher the motor's rotational speed n, the greater the back EMF E.

[0057] Correspondingly, when the aforementioned motor is a variable frequency motor inside the range hood, the motor speed n can reach its maximum value when the back electromotive force E is infinitely close to the motor supply voltage. At this time, the range hood can also reach its maximum airflow and maximum static pressure. Therefore, by increasing the motor supply voltage, the maximum airflow and maximum static pressure of the variable frequency range hood can be increased accordingly.

[0058] Based on this, the present application provides a power control method. Compared with the above-mentioned field weakening control method, this method provides two power modes for the motor by using the different output voltages of the first and second input units in the applied power control circuit. In one of the modes, after the second input unit completes the boost operation, its discharge voltage is higher than the original drive voltage, thereby increasing the motor power by increasing the power supply voltage to the motor.

[0059] In one possible implementation, the power control method provided in this application is applicable to a power control circuit 10, which is connected to a motor and whose output voltage can be the power supply voltage of the motor.

[0060] For example, Figure 1 This is one of the schematic diagrams of the power control circuit 10 provided in the embodiments of this application, such as... Figure 1 As shown, the power control circuit 10 includes a first input unit 11 and a second input unit 12. The output terminals of the first input unit 11 and the second input unit 12 are respectively connected to the motor. That is, the output voltage of the first input unit 11 or the second input unit 12 is the power supply voltage of the motor.

[0061] In specific implementation, in the first mode, the first input unit 11 can input the original driving voltage to the motor to provide the motor with a normal power supply voltage; in the second mode, the second input unit 12 can discharge to the motor after completing the boost operation to input a discharge voltage higher than the original driving voltage to the motor, thereby providing the motor with a boosted power supply voltage.

[0062] It should be noted that the normal power supply voltage provided by the first input unit 11 to the motor can be understood as the power supply voltage of the motor under normal power conditions, that is, the first mode corresponds to the normal power mode of the motor; correspondingly, the discharge voltage provided by the second input unit 12 to the motor, which is higher than the original drive voltage, can be understood as the power supply voltage of the motor in the power boost mode, that is, the second mode corresponds to the power boost mode of the motor.

[0063] In one possible implementation, Figure 1 The power control circuit 10 shown can be installed in a frequency converter 20.

[0064] For example, Figure 2 This is a schematic diagram of the operation of the frequency converter 20 provided in the embodiments of this application, as shown below. Figure 2 As shown, the frequency converter 20 responds to the frequency conversion signal and adjusts the power supply voltage of the motor by switching the voltage output objects (i.e., the first input unit 11 and the second input unit 12) in the power control circuit 10, thereby adjusting the speed of the motor and realizing the frequency conversion effect of the motor.

[0065] Correspondingly, the frequency conversion signal received by the frequency converter 20 can correspond to the first mode and the second mode described above, respectively. Specifically, in the first mode, the frequency converter 20 switches the voltage output object of the power control circuit 10 to the first input unit 11; in the second mode, the frequency converter 20 switches the voltage output object of the power control circuit 10 to the second input unit 12.

[0066] Without applying the field weakening control method, for the same motor, based on the frequency converter 20 provided in the embodiments of this application, two configurations on the same PCB can be realized. When different frequency conversion signals are received, the motor power can be configured as the currently common conventional power or as the enhanced power that significantly increases the maximum air volume and maximum static pressure by adjusting the motor power supply voltage.

[0067] Figure 3 This is a schematic flowchart of a power control method provided in an embodiment of this application, such as... Figure 3 As shown, this method can be applied to the aforementioned power control circuit 10, and specifically includes the following steps:

[0068] In step S301, in the first mode, the original drive voltage is input to the motor through the first input unit 11.

[0069] In one possible implementation, the original driving voltage can be the voltage signal obtained after rectification and filtering of the voltage input from the external power supply to the power control circuit 10.

[0070] Correspondingly, the first input unit 11 may include a second filter module and a reactor. The second filter module is used to convert alternating current (AC) into direct current (DC) and filter the rectified pulsating DC (with the direction unchanged but the amplitude fluctuating drastically) into a stable DC voltage. The reactor is used to control and optimize the circuit current in the first input unit 11.

[0071] For example, Figure 4 This is a second schematic diagram of the power control circuit 10 provided in the embodiments of this application, as shown below. Figure 4 As shown, the first input unit 11 is composed of a second filter module 111 and a reactor 112. The second filter module 111 specifically includes a rectifier bridge 401 and a filter capacitor 402. The rectifier bridge 401 is connected to an external power supply and one end of the reactor 112, respectively. The filter capacitor 402 is connected to the output terminal of the power control circuit 10 and the other end of the reactor 112, respectively.

[0072] Specifically, refer to Figure 4The working process of the first input unit 11 is as follows: the rectifier bridge 401 first rectifies the AC power input from the external power source into DC power. Then, the rectified DC power is filtered by the filter capacitor 402 through the reactor 112 to generate voltage V0, so as to form the original driving voltage V' output by the power control circuit 10.

[0073] For example, when the external power input voltage is AC voltage 220V, the output voltage V0 (i.e., the original drive voltage V') can be a fixed multiple of the AC voltage, 310V (where the fixed multiple corresponds to 1.414). Based on this, in the motor's normal power mode (i.e., the first mode), the first input unit 11 can output the original drive voltage 310V.

[0074] In step S302, in the second mode, the second input unit 12, which has completed the boost operation, discharges to the motor, and inputs a discharge voltage higher than the original drive voltage to the motor. The original drive voltage and the discharge voltage have the same polarity.

[0075] In this embodiment, the discharge of the second input unit 12 after charging makes the output voltage of the power control circuit 10 higher than the original driving voltage, thereby increasing the power supply voltage to the motor and improving the motor power.

[0076] In one possible implementation, the discharge voltage of the second input unit 12 can be controlled based on the comparison result between the output voltage V0 of the power control circuit 10 and the reference voltage Vf; wherein the reference voltage Vf can be the required voltage of the motor in the power boost mode, for example, 400V.

[0077] For example, when the output voltage V0 of the power control circuit 10 is less than the reference voltage Vf, the discharge voltage V'' of the second input unit 12 is controlled to be higher than the original drive voltage V'.

[0078] In another embodiment of this application, a specific distribution of the second input unit 12 is also provided.

[0079] In one possible implementation, the second input unit 12 includes a first filtering module and a voltage boost control module. The input terminal of the first filtering module is configured to receive a voltage signal from an external power source, and to output the original driving voltage V' after rectifying and filtering the voltage signal from the external power source. The voltage boost control module is used to control the discharge voltage V'' of the second input unit 12 to be higher than the original driving voltage V' based on the comparison result between the output voltage V0 of the power control circuit 10 and the reference voltage Vf.

[0080] For example, Figure 5 This is the third schematic diagram of the power control circuit 10 provided in the embodiments of this application, as shown below. Figure 5As shown, the second input unit 12 is composed of a first filtering module 121 and a voltage boost control module 122. The first filtering module 121 specifically includes a rectifier bridge 501 and a filter capacitor 502. The rectifier bridge 501 is connected to an external power supply and one end of the voltage boost control module 122, respectively, and the filter capacitor 502 is connected to the output terminal of the power control circuit 10.

[0081] The voltage boost control module 122 specifically includes a feedback submodule 503, a drive submodule 504, and an energy storage submodule 505. The input terminal of the feedback submodule 503 is connected to the output terminal of the power control circuit 10 to sample the voltage signal output by the power control circuit 10 and feed the voltage signal output by the power control circuit 10 back to the drive submodule 504. The drive submodule 504 is connected to both the input terminal of the feedback submodule 503 and the output terminal of the energy storage submodule 505 to control the discharge status of the energy storage submodule 505 according to the voltage signal fed back by the feedback submodule 503.

[0082] Specifically, refer to Figure 5 The workflow of the second input unit 12 is as follows: the feedback submodule 503 feeds back the voltage signal output by the sampled power control circuit 10 to the drive submodule 504; when the voltage signal output by the power control circuit 10 is less than the reference voltage Vf, the drive submodule 504 boosts the voltage of the energy storage submodule 505 and maintains it stable within the corresponding voltage range after boosting.

[0083] In one example, the feedback submodule 503 includes an FB feedback network to adjust the feedback signal based on sampling of the output voltage signal; the energy storage submodule 505 is a power factor correction (PFC) inductor to store energy during the charging phase and release energy during the discharging phase; the drive submodule 504 includes a driver PD0 and a switch Q0, wherein the switch Q0 can be a transistor and the driver PD0 can be a driver device for the transistor.

[0084] Correspondingly, Figure 6 This is the fourth schematic diagram of the power control circuit 10 provided in the embodiments of this application, as shown below. Figure 6 As shown, the drive submodule 504 includes a driver 601 and a switch 602; the input terminal of the driver 601 is connected to the feedback submodule 503 to receive the feedback signal from the feedback submodule 503; the output terminal of the driver 601 is connected to the first terminal of the switch 602, the second terminal of the switch 602 is connected to the energy storage submodule 505, and the third terminal of the switch 602 is grounded; wherein, the first terminal of the switch 602 can be a control terminal.

[0085] Specifically, when the driver 601 determines, based on the feedback signal input from the feedback submodule 503, that the voltage signal output by the power control circuit 10 is less than the reference voltage Vf, the driver 601 inputs a first control signal to the first terminal of the switch 602, thereby turning on the second and third terminals of the switch 602 to charge the energy storage submodule 505.

[0086] Optionally, when the driver 601 can determine, based on the feedback signal input from the feedback submodule 503, that the voltage signal output by the power control circuit 10 is greater than the reference voltage Vf, the driver 601 inputs a second control signal to the first terminal of the switch 602, thereby cutting off the second and third terminals of the switch 602, so as to control the energy storage submodule 505 to discharge and cause the discharge voltage V'' to rise.

[0087] It should be noted that the reason why the energy storage submodule 505 can discharge when the second and third terminals of the switch 602 are turned off is because when the second and third terminals of the switch 602 are turned on, the current through the energy storage submodule 505 increases, and the inductor stores energy at this time; while when the second and third terminals are turned off, the current through the energy storage submodule 505 decreases, the inductor generates a reverse electromotive force to maintain the current direction, and the energy storage submodule 505 is forced to release energy at this time.

[0088] In another embodiment of this application, another method for the driver 601 to receive control signals is also provided.

[0089] In one possible implementation, the driver 601 can also receive software control signals to input corresponding control signals to the first terminal of the switch 602 according to the software control signals.

[0090] For example, the software control signal can be a software-generated digital control signal (Switch Control signal, abbreviated as SW_CTRL signal) to control the switching transistor 602 to turn on or off.

[0091] Specifically, the driver 601 is used to receive a first electronic switch control signal and, in response to the first electronic switch control signal, input a first control signal to the first terminal of the switch 602 to turn on the second and third terminals of the switch 602, thereby charging the energy storage submodule 505; the driver 601 is also used to receive a second electronic switch control signal and, in response to the second electronic switch control signal, input a second control signal to the first terminal of the switch 602 to turn off the second and third terminals of the switch 602, controlling the energy storage submodule 505 to discharge and causing the discharge voltage V'' to increase.

[0092] In another embodiment of this application, other device distributions for the second input unit 12 are also provided.

[0093] In one possible implementation, the feedback submodule 503 may also include a diode D0, and the drive submodule 504 may also include a current detector Rcs.

[0094] For example, Figure 7 This is the fifth schematic diagram of the power control circuit 10 provided in the embodiments of this application, as shown below. Figure 7 As shown, the diode 701 set in the feedback submodule 503 is connected to the output terminal of the energy storage submodule 505, the input terminal of the output capacitor 502, and the FB feedback network, respectively.

[0095] Specifically, diode 701 is used to reverse cut off when the second and third terminals of switch 602 are off, so as to prevent the energy of output capacitor 502 from flowing back to energy storage submodule 505 or input side; output capacitor 502 is used to supply power to the load when the second and third terminals of switch 602 are on, so as to avoid a sudden drop in load voltage, and is also used to charge itself through energy storage submodule 505 when the second and third terminals of switch 602 are off.

[0096] For example, such as Figure 7 As shown, a current detector 702 is provided between the third terminal of the switch 602 and the ground terminal to achieve peak current control, cycle-by-cycle overcurrent protection, power factor correction, and improved system energy efficiency.

[0097] It should be noted that the driver 601 can also receive the current signal from the energy storage submodule 505 to achieve power factor correction and current mode control. Specifically, the driver 601 can control the switch 602 based on the current signal of the energy storage submodule 505 so that the current of the energy storage submodule 505 can track the waveform of the input voltage; the driver 601 can also immediately turn off the switch when the sampled value of the current signal reaches the current loop setpoint, based on the current signal of the energy storage submodule 505, to prevent the switch from being overloaded and damaged.

[0098] In another embodiment of this application, a range hood 30 is also provided, which includes the above-mentioned components. Figure 2 The frequency converter 20 shown can also be referred to as a frequency converter board in this case.

[0099] In one possible implementation, the range hood 30 is used to execute the control program of the frequency converter 20 according to the frequency converter control command.

[0100] For example, the range hood 30 is used to obtain the concentration of oil fumes in the current cooking environment, so as to generate a frequency conversion control command based on the concentration of oil fumes, thereby executing the control program of the frequency converter 20 accordingly.

[0101] Specifically, when the fume concentration determined by the range hood 30 is less than a preset threshold, a first frequency conversion signal can be sent to the frequency converter 20, so that the frequency converter 20 controls the internal power control circuit 10 to continuously output the original drive voltage V' to the motor; otherwise, when the fume concentration determined by the range hood 30 is greater than or equal to the preset threshold, a second frequency conversion signal can be sent to the frequency converter 20, so that the frequency converter 20 controls the internal power control circuit 10 to output a discharge voltage V'' higher than the original drive voltage V' to the motor. The preset threshold is, for example, the maximum allowable emission concentration of fume.

[0102] Optionally, frequency converter control commands can be generated according to the user's customized requirements.

[0103] For example, the frequency conversion signal sent by the range hood 30 to the frequency converter 20 can be a frequency conversion signal automatically generated by the internal processing module of the range hood 30 based on the current oil fume concentration; or it can be a frequency conversion signal generated by the range hood 30 displaying the current oil fume concentration in the display control area and receiving user control commands.

[0104] In one example, when the aforementioned preset threshold is 3 mg / m³, Figures 8a-8b This is a schematic diagram illustrating a process by which the range hood 30 generates a frequency conversion signal, as provided in an embodiment of this application. Figure 8a As shown, the range hood 30 displays the detected oil fume concentration of 5mg / m³ in the current cooking environment within its own display and control area, and simultaneously prompts the user "Oil fume pollution exists, do you want to activate the inverter function?"; Figure 8b As shown, when the user clicks the "Start Inverter Function" control, the range hood 30 responds to the function instruction of this control and generates an inverter signal, so that the inverter device 20 controls the internal power control circuit 10 to adjust the motor power supply voltage.

[0105] The range hood 30 provided in this application embodiment can, on the one hand, provide different power supply voltages to the motor through the different outputs of the first and second input units in the internal power control circuit 10 in different modes, thereby obtaining two power modes of the motor; on the other hand, in the second mode, after the second input unit completes the boost operation, its discharge voltage is higher than the original drive voltage, thereby increasing the power supply voltage of the motor, improving the motor power and power factor, and reducing the motor's heat generation.

[0106] In another embodiment of this application, another distribution of the power control circuit 10 is also provided.

[0107] For example, Figure 9 This is the sixth schematic diagram of the power control circuit 10 provided in the embodiments of this application, as shown below. Figure 9As shown, the rectifier module 901 can achieve the rectification effect of the input current by the first input unit 11 and the second input unit 12; the inductor module 902 may include a switching device 9021, a reactor 112 and a PFC inductor 505, so that the switching device 9021 is connected to the reactor 112 in the first mode and connected to the PFC inductor 505 in the second mode. The switching device 9021 is, for example, a single-pole double-throw switch; secondly, a short-circuit block SW0 is also provided between the inductor module 902 and the output terminal, so that SW0 is closed in the first mode to allow the current to be output through the short-circuit block SW0 and open in the second mode to allow the current to be output through the diode D0.

[0108] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A power control circuit, characterized by, The power control circuit includes a first input unit and a second input unit; the output terminals of the first input unit and the second input unit are respectively connected to the motor. The first input unit is used to input the original drive voltage to the motor in a first mode; The second input unit is used, in the second mode, to perform a boost operation and discharge to the motor, so as to input a discharge voltage higher than the original drive voltage to the motor; the original drive voltage and the discharge voltage have the same polarity; The original driving voltage is the voltage signal obtained after rectification and filtering of the voltage input from the external power supply to the power control circuit.

2. The power control circuit of claim 1, wherein, The second input unit includes: a first filtering module and a voltage boost control module. The input terminal of the first filtering module is configured to receive the voltage signal input from the external power supply, so as to rectify and filter the voltage signal input from the external power supply. The voltage boost control module is used to control the discharge voltage of the second input unit to be higher than the original driving voltage based on the comparison result between the output voltage of the power control circuit and the reference voltage.

3. The power control circuit of claim 2, wherein, The voltage boost control module includes a feedback submodule, a drive submodule, and an energy storage submodule. The input terminal of the energy storage submodule is connected to the output terminal of the filter module, the output terminal of the energy storage submodule is connected to the drive submodule, and the feedback submodule is connected to both the output terminal of the power control circuit and the drive submodule. The feedback submodule is used to sample the voltage signal output by the power control circuit; The drive submodule is used to boost the voltage of the energy storage submodule when the voltage signal output by the power control circuit is less than the reference voltage, and maintain the voltage within the corresponding voltage range after boosting.

4. The power control circuit of claim 3, wherein, The drive submodule includes a driver and a switch. The input terminal of the driver is connected to the feedback submodule, the output terminal of the driver is connected to the first terminal of the switch, the second terminal of the switch is connected to the energy storage submodule, and the third terminal of the switch is grounded. The driver is used to input a first control signal to the first terminal of the switch when the voltage signal output by the power control circuit is less than the reference voltage, thereby connecting the second terminal and the third terminal of the switch to charge the energy storage submodule. The driver is also used to input a second control signal to the first terminal of the switch when the voltage signal output by the power control circuit is greater than the reference voltage, thereby cutting off the second terminal and the third terminal of the switch and controlling the energy storage submodule to discharge to cause the discharge voltage to rise.

5. The power control circuit of claim 3, wherein, The energy storage submodule is a power factor correction inductor.

6. The power control circuit according to claim 1, characterized in that, The first input unit includes a second filter module and a reactor, wherein the output terminal of the second filter module is connected to the input terminal of the reactor; The input terminal of the second filtering module is configured to receive the voltage signal input from the external power supply, and to input the original driving voltage to the motor through the output terminal of the reactor after rectifying and filtering the voltage signal input from the external power supply.

7. The power control circuit of claim 1, wherein, The power control circuit also includes switching devices. The switching device is used to cause the power control circuit to enter the first mode when closed; The switching device is also used to cause the power control circuit to enter the second mode when it is disconnected.

8. The power control circuit of claim 4, wherein, The power control circuit is also used for: The system receives a first electronic switch control signal and, in response to the first electronic switch control signal, charges the energy storage submodule. The first electronic switch control signal is used to control the switch to be turned on. The system receives a second electronic switch control signal and, in response to the second electronic switch control signal, controls the energy storage submodule to discharge, causing the discharge voltage to rise. The second electronic switch control signal is used to control the switch to turn off.

9. A frequency conversion device, characterized by The power control circuit includes any one of claims 1-8, wherein the frequency converter responds to the frequency conversion signal and adjusts the power supply voltage of the motor to adjust the speed of the motor.

10. A range hood, characterized by The range hood includes the frequency converter as described in claim 9, wherein the range hood is used to execute the control program of the frequency converter according to the frequency converter control command.

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