Air conditioner

Abstract

The utility model discloses an air conditioner. According to the air conditioner, when alternating current passes through the bridgeless PFC circuit, the positive half cycle and the negative half cycle flow through the branch between the source electrode of the first switching tube and the source electrode of the second switching tube, so that the detection circuit is arranged between the source electrode of the first switching tube and the source electrode of the second switching tube; the detection circuit can detect the voltage value of the positive half-cycle alternating current and the voltage value of the negative half-cycle alternating current at the same time, so that the detection circuit can output a control signal according to the magnitude relation between the detected voltage values and the preset voltage, and the control circuit can control the alternating current according to the control signal. And when the first switching tube and the second switching tube are switched on or switched off, the bridgeless PFC circuit and the AC power supply are switched on, or the bridgeless PFC circuit and the AC power supply are switched off, so that the device cost can be reduced, and the board arrangement space is reduced.

Description

Technical Field

[0001] This application relates to electronic technology, and to, but is not limited to, an air conditioner. Background Technology

[0002] Bridgeless power factor correction (PFC) circuits have promising applications due to their advantages such as fewer power devices, effective reduction of circuit harmonics, and high efficiency. Their working principle involves adjusting the input current waveform by controlling the duty cycle of the power devices in the upper and lower bridge arms. However, the efficiency and power factor correction effect are directly affected by the sampling accuracy of the sampling circuit.

[0003] Currently, sampling resistors are commonly used to acquire the current in bridgeless PFC circuits. Typically, the sampling resistor is placed at one end of the power switching device, thus capturing the current flowing through it. This method offers advantages such as good stability, shared grounding between the controller and power drive, good electromagnetic compatibility (EMI), and effective protection when the current at the power switching device exceeds a threshold. However, since PFC circuits include multiple power switching devices, multiple sampling resistors need to be set for each device, resulting in high cost and space requirements, making implementation difficult. Utility Model Content

[0004] In view of this, the air conditioner provided in the embodiments of this application can reduce component costs and reduce board space.

[0005] An air conditioner provided in this application embodiment includes:

[0006] The AC input terminal includes a first input terminal and a second input terminal, wherein the first input terminal and the second input terminal have different polarities;

[0007] A bridgeless PFC circuit includes an inductor, a first switching transistor, a second switching transistor, a first rectifier transistor, a second rectifier transistor, and an output capacitor. The first end of the inductor is connected to the first input terminal, and the second end of the inductor is connected to the positive terminal of the first rectifier transistor and the drain of the first switching transistor. The drain of the second switching transistor is connected to the second input terminal and the positive terminal of the second rectifier transistor. The first end of the output capacitor is connected to the negative terminal of the first rectifier transistor and the negative terminal of the second rectifier transistor. The second end of the output capacitor is connected to ground, the source of the first switching transistor, and the source of the second switching transistor.

[0008] A detection circuit is disposed between the source of the first switching transistor and the source of the second switching transistor. The detection circuit is used to obtain and output a control signal based on a first voltage between the source of the first switching transistor and the source of the second switching transistor. The control signal is used to indicate the magnitude relationship between the first voltage and a preset voltage.

[0009] A control circuit is provided, the output of which is connected to the output of the detection circuit. The output of the control circuit is also connected to the gate of the first switch and the gate of the second switch, respectively, for obtaining and controlling the first switch and the second switch to be turned on or off according to the control signal.

[0010] In the aforementioned air conditioner, because the AC current flows through the branch between the sources of the first and second switching transistors during both the positive and negative half-cycles of the bridgeless PFC circuit, a detection circuit is set between the sources of the first and second switching transistors. This detection circuit can simultaneously detect the voltage values ​​of the AC current during both the positive and negative half-cycles. Based on the relationship between the detected voltage value and a preset voltage, the detection circuit outputs a control signal. This allows the control circuit to turn the first and second switching transistors on or off according to the control signal, thereby connecting or disconnecting the bridgeless PFC circuit from the AC power supply. This reduces component costs and board space requirements.

[0011] In one embodiment, the detection circuit includes a first sampling resistor, a first differential amplifier, and a comparator, wherein the first sampling resistor is disposed between the source of the first switching transistor and the source of the second switching transistor, wherein:

[0012] The first input terminal of the first differential amplifier is connected to the first terminal of the first sampling resistor, the second input terminal of the first differential amplifier is connected to the second terminal of the first sampling resistor, and the output terminal of the first differential amplifier is connected to the first input terminal of the comparator, for obtaining and obtaining the first voltage based on the voltage difference across the first sampling resistor;

[0013] The first input terminal of the comparator is connected to the output terminal of the first differential amplifier, the second input terminal of the comparator is connected to the reference power supply, and the output terminal of the comparator is connected to the control circuit. The comparator is used to obtain the first voltage and output the control signal according to the relationship between the first voltage and the preset voltage output by the reference power supply.

[0014] It is understandable that by using a first differential amplifier to output the first voltage sampled by the first sampling resistor to a comparator, the comparator can output a control signal. Using hardware circuitry to implement the output of the control signal is less costly and more reliable than using a processor to output the control signal.

[0015] In one embodiment, the control signal includes a first signal and a second signal, the preset voltage includes a first threshold and a second threshold, and the comparator includes a first comparator and a second comparator, wherein:

[0016] The first comparator has its negative input terminal connected to a reference power supply via a first resistor, its non-inverting input terminal connected to the output terminal of the first differential amplifier, and its output terminal connected to the control circuit. It is used to output the first signal based on the relationship between the first voltage and the first threshold.

[0017] The second comparator has its non-inverting input connected to a reference power supply via a second resistor, its negative input connected to the output of the first differential amplifier, and its output connected to the control circuit. It is used to output the second signal based on the relationship between the first voltage and the second threshold. The first resistor and the second resistor have different resistance values.

[0018] Understandably, by setting up two comparators to compare the first voltage, the preset voltage can be set to a range value, thereby improving the accuracy of the control signal output.

[0019] In one embodiment, the control circuit includes a controller and a driver, wherein:

[0020] The controller is connected to the driver and is used to output a drive signal. The drive signal is used to control the target switch to be turned on or off. The target switch includes the first switch and / or the second switch.

[0021] The driver includes an input terminal, an enable terminal, a first output terminal, and a second output terminal. The first output terminal is connected to the gate of the first switching transistor, and the second output terminal is connected to the gate of the second switching transistor. The input terminal is connected to the controller, and the enable terminal is connected to the detection circuit. The driver is used to obtain the driving signal and, when the magnitude relationship between the first voltage and the preset voltage meets the operating conditions of the driver, amplify the driving signal and output the processed driving signal to the target switching transistor.

[0022] It is understandable that by setting a driver to amplify the drive signal output by the controller, the requirements for the controller's output voltage can be reduced, thereby reducing the cost of the components.

[0023] In one embodiment, the drive signal includes a first drive signal and a second drive signal, the input terminal of the driver includes a first input terminal and a second input terminal, and the controller includes a first output terminal and a second output terminal, wherein:

[0024] The first output terminal of the controller is connected to the first input terminal of the driver. The controller is used to output the first drive signal to drive the first switching transistor to turn on or off through the driver.

[0025] The second output terminal of the controller is connected to the second input terminal of the driver. The controller is used to output the second drive signal to drive the second switching transistor to turn on or off through the driver.

[0026] Understandably, by connecting the two input terminals of the driver to the two output terminals of the controller respectively, the controller can output two drive signals to drive the two switching transistors respectively, thereby improving reliability.

[0027] In one embodiment, both the first drive signal and the second drive signal are PWM signals.

[0028] Understandably, the controller drives the switching transistors by outputting PWM signals, enabling the periodic switching of the first and second switching transistors, thereby achieving the AC-to-DC voltage conversion function of the bridgeless PFC circuit and improving reliability.

[0029] In one embodiment, the input of the controller is also connected to the output of the comparator, for outputting a drive signal indicating to disconnect the first and second switching transistors when the magnitude relationship between the first voltage and the preset voltage does not meet the operating conditions of the air conditioner.

[0030] It is understandable that by connecting the output of the comparator to the controller, the controller can disconnect the first and second switching transistors when the relationship between the first voltage and the preset voltage does not meet the operating conditions of the air conditioner, thereby preventing the power management module from outputting DC power and protecting the hardware safety of the air conditioner.

[0031] In one embodiment, the air conditioner further includes a sampling circuit, the input terminal of which is connected to the output capacitor and the output terminal of which is connected to the detection circuit, for obtaining a second voltage at the input terminal of the output capacitor and outputting the second voltage to the control circuit so that the control circuit adjusts the DC current according to the second voltage.

[0032] It is understandable that by setting a sampling circuit at the output capacitor, the controller can receive an accurate second voltage at the output capacitor, thereby enabling the control circuit to adjust the duty cycle of the switching transistor according to the second voltage, providing hardware support for determining whether the air conditioner is operating normally and improving reliability.

[0033] In one embodiment, the sampling circuit includes a second sampling resistor and a second differential amplifier. A first terminal of the second sampling resistor is connected to the output capacitor, and a second terminal of the second sampling resistor is connected to both the detection circuit and the source of the second switching transistor.

[0034] The first input terminal of the second differential amplifier is connected to the first terminal of the second sampling resistor, the second input terminal of the second differential amplifier is connected to the second terminal of the second sampling resistor, and the output terminal of the second differential amplifier is connected to the control circuit. The second voltage is obtained based on the voltage difference across the second sampling resistor and then output to the control circuit.

[0035] It is understandable that by using a second differential amplifier to output the output voltage acquired by the second sampling resistor to the control circuit, and implementing the detection of the second voltage using hardware circuitry, the cost is lower and the reliability is higher.

[0036] In one embodiment, the resistance value of the second sampling resistor is greater than the resistance value of the first sampling resistor.

[0037] It is understandable that setting the resistance of the second sampling resistor to a larger value can improve the accuracy of the output voltage calculation, while setting the resistance of the first sampling resistor to a smaller value can reduce the loss of AC power during transmission between the source of the first switching transistor and the source of the second switching transistor. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application.

[0039] Figure 1 This is one of the structural schematic diagrams of the power management module provided in the embodiments of this application;

[0040] Figure 2 This is a schematic diagram of the structure of the bridgeless PFC circuit provided in the embodiments of this application;

[0041] Figure 3A A current flow diagram of a bridgeless PFC circuit during the positive half-cycle provided in an embodiment of this application;

[0042] Figure 3B A current flow diagram of a bridgeless PFC circuit during the negative half-cycle provided in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the control circuit provided in an embodiment of this application;

[0044] Figure 5 This is the second schematic diagram of the power management module provided in the embodiments of this application;

[0045] Figure 6 This is a schematic diagram of the detection circuit provided in an embodiment of this application;

[0046] Figure 7 This is one of the schematic diagrams of the implementation structure of the detection circuit provided in the embodiments of this application;

[0047] Figure 8 This is a second schematic diagram of the implementation structure of the detection circuit provided in the embodiments of this application;

[0048] Figure 9 This is the third schematic diagram of the power management module provided in the embodiments of this application;

[0049] Figure 10 Fourth schematic diagram of the power management module provided in the embodiments of this application;

[0050] Figure 11 A schematic diagram illustrating the implementation structure of the power management module provided in this application embodiment;

[0051] Figure 12 Fifth schematic diagram of the power management module provided in the embodiments of this application;

[0052] Figure 13 This is a schematic diagram of the implementation structure of the power management module provided in an embodiment of this application. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0055] It should be noted that the terms "first, second, third" used in the embodiments of this application are used to distinguish similar or different objects and do not represent a specific order of objects. It can be understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0056] This application provides an air conditioner that performs a refrigeration cycle by using a compressor, an indoor fan, an outdoor fan, a condenser, an expansion valve, and an evaporator.

[0057] The air conditioner includes a casing and a power management module installed inside the casing. The input terminal of the power management module is connected to an AC power source, and the output terminal of the power management module is connected to various air conditioning components inside the casing. It is used to convert the AC power output from the AC power source into DC power to provide power to various loads of the air conditioner, thereby enabling the air conditioner to operate normally. The loads include the compressor, indoor fan, and outdoor fan.

[0058] The power management module contains a circuit board on which several components are connected.

[0059] The power management module includes an AC input terminal 101, a bridgeless PFC circuit 102, and a control circuit 103, such as... Figure 1 As shown, the input terminal of the bridgeless PFC circuit 102 is connected to the AC input terminal 101, and the output terminal of the bridgeless PFC circuit 102 is connected to the control circuit 103.

[0060] AC input terminal 101 is connected to AC power supply. When AC power supply and power management module are connected, AC input terminal 101 is connected to output terminal of AC power supply, thereby outputting AC power to bridgeless PFC circuit 102 through AC input terminal 101.

[0061] In some embodiments, the AC input terminal 101 may include a first input terminal and a second input terminal, which are respectively connected to a plurality of output terminals of the AC power supply. The first input terminal and the second input terminal have different polarities. For example, the first input terminal may be a live wire connection terminal, which is connected to the live wire terminal of the AC power supply, and the second input terminal may be a neutral wire connection terminal, which is connected to the neutral wire terminal of the AC power supply.

[0062] The bridgeless PFC circuit 102 includes an inductor L, a first switching transistor Q1, a second switching transistor Q2, a first rectifier diode D1, a second rectifier diode D2, and an output capacitor C, as follows: Figure 2 As shown, the first end of the inductor is connected to the first input terminal, and the second end of the inductor is connected to the positive terminal of the first rectifier and the drain of the first switching transistor. The drain of the second switching transistor is connected to the second input terminal and the positive terminal of the second rectifier. The first end of the output capacitor is connected to the first power supply terminal of the load, the negative terminal of the first rectifier and the negative terminal of the second rectifier. The second end of the output capacitor is connected to the second power supply terminal of the load, the ground terminal, the source of the first switching transistor and the source of the second switching transistor.

[0063] When the bridgeless PFC circuit 102 is working, it can be divided into two stages according to the polarity of the AC voltage within one power frequency cycle: the positive half-cycle and the negative half-cycle. Both the positive half-cycle and the negative half-cycle can be divided into the charging process of inductor L and the discharging process of inductor L.

[0064] Figure 3A The diagram shows the current flow of the bridgeless PFC circuit 102 during the charging process of inductor L in the positive half-cycle. During this time, switch Q1 is periodically switched on and off, while switch Q2 remains off. The current mainly flows through the following paths: When switch Q1 is on, AC current is output from the live wire terminal, then sequentially passes through inductor L, switch Q1, and the body diode of switch Q2 before being output to the neutral wire terminal. Figure 3A As shown by the solid line portion; when the switch Q1 is off, the AC power output from the live wire terminal passes sequentially through the inductor L, rectifier D1, output capacitor, and the body diode of the switch Q2 before being output to the neutral wire terminal, as shown. Figure 3A As shown by the dashed line, thus through Figure 3A The two processes shown (solid and dashed lines) enable the AC power supply to charge the inductor L. The conduction duration of the switch Q1 within one on / off cycle is determined by the duty cycle of the drive signal output by the controller 1031 to the switch Q1.

[0065] During the discharge process of the positive half-cycle, both switching transistors Q1 and Q2 are turned off, and the inductor L discharges to the output capacitor C, thereby outputting DC power to the load through the output capacitor C.

[0066] Figure 3B The diagram shows the current flow of the bridgeless PFC circuit 102 during the charging process of inductor L in the negative half-cycle. During this time, switch Q2 is periodically switched on and off, while switch Q1 remains off. The current mainly flows through the following paths: When switch Q2 is on, the AC current is output from the neutral terminal, then sequentially passes through inductor L, switch Q2, and the body diode of switch Q1 before being output to the neutral terminal. Figure 3B The solid line portion shown indicates that when switch Q2 is off, the AC power output from the neutral terminal passes sequentially through rectifier D2, output capacitor, and the body diode of switch Q1 before being output to the neutral terminal. Figure 3B As shown by the dashed line, thus through Figure 3BThe two processes shown (solid and dashed lines) enable the AC power supply to charge the inductor L. The conduction duration of switch Q2 within one on / off cycle is determined by the duty cycle of the drive signal output by controller 1031 to switch Q2.

[0067] During the discharge process of the negative half-cycle, both switching transistors Q1 and Q2 are turned off, and the inductor L discharges to the output capacitor C, thereby outputting DC power to the load through the output capacitor C.

[0068] In some embodiments, the first and second switching transistors can be MOS transistors or IGBT transistors, which can be set by those skilled in the art according to the actual situation. This application does not impose any restrictions on these embodiments.

[0069] Preferably, both the first and second switching transistors can be MOSFETs, thereby reducing switching losses.

[0070] In some embodiments, the control circuit 103 may include a controller 1031, which is connected to the gates of the first switch and the second switch, and is used to output a drive signal to control the on / off state of the first switch and the second switch.

[0071] In other embodiments, the control circuit 103 may include a controller 1031 and a driver 1032, such as Figure 4 As shown, the output terminal of the controller 1031 is connected to the input terminal of the driver 1032, and the output terminal of the driver 1032 is connected to the gate of the first switch and the second switch. The controller 1031 outputs a drive signal, the driver 1032 amplifies the drive signal, and outputs the processed drive signal to the first switch and the second switch, thereby controlling the on and off of the first switch and the second switch.

[0072] It is understandable that after being amplified by the driver 1032, the controller 1031 can be adapted to switching transistors that require higher drive voltages.

[0073] In the current operating environment of air conditioners, fluctuations in the input power grid can cause deviations in the input voltage between any two moments. If the modulation of the PFC circuit within the air conditioner is not timely, it can easily lead to an increase in the DC bus voltage, causing the air conditioner to shut down or damage components. Therefore, air conditioners need to detect the DC bus voltage to determine whether the voltage is normal at any given moment. When an abnormal voltage occurs, the duty cycle of the switching transistors should be adjusted in a timely manner to restore the DC bus voltage to its normal value. The DC bus voltage detection can generally be performed on either the AC or DC side. However, when performed on the DC side, the controller 1031 has a longer response time to the power switching devices, which can lead to a slower response in adjusting the duty cycle of the two switching transistors and may cause device damage. Therefore, voltage detection is usually performed on the AC side.

[0074] When detecting the voltage on the AC side, a sampling resistor is typically placed at one end of the power switching device. This allows the current flowing through the power switching device to be collected via the sampling resistor. This method offers advantages such as good stability, a common ground for the controller 1031 and the power drive, good electromagnetic compatibility (EMI), and effective protection when the current at the power switching device exceeds a threshold. However, since the PFC circuit includes multiple power switching devices, multiple sampling resistors need to be set for each device to detect the electrical parameters of the electrical signals flowing through them. This results in high cost and occupies board space, making its implementation difficult.

[0075] Based on the above problems, this embodiment proposes a detection circuit, applied to the bridgeless PFC circuit 102, such as... Figure 5 As shown, the first terminal of the detection circuit is connected to the source of the first switching transistor, and the second terminal of the detection circuit is connected to the source of the second switching transistor. The detection circuit is used to obtain and output a control signal to the control circuit 103 based on the first voltage between the sources of the first and second switching transistors. The control signal is used to indicate the magnitude relationship between the first voltage and a preset voltage. After receiving the control signal, the control circuit 103 can adjust the electrical parameters of the output DC power according to the control signal.

[0076] In some embodiments, the adjustment method of DC power can refer to the adjustment method in related technologies. For example, when the control signal indicates that the first voltage is less than the preset voltage, it means that the DC voltage value cannot meet the normal operation requirements of the air conditioner. At this time, the control circuit 103 can increase the duty cycle of the switching transistor to prolong the conduction time of the switching transistor and increase the output voltage value of the power management module. When the control signal indicates that the first voltage is greater than the preset voltage, it means that the DC voltage value is too large and may cause the risk of overvoltage damage. At this time, the control circuit 103 can reduce the duty cycle of the switching transistor to reduce the conduction time of the switching transistor and reduce the output voltage value of the power management module. The embodiments of this application do not impose any limitations.

[0077] During the detection process, the control circuit 103 outputs drive signals to the first and second switching transistors to enable them to operate. Specifically, during the positive half-cycle, the first switching transistor Q1 is periodically switched on and off, while the second switching transistor Q2 remains off. The positive voltage is output from the live wire terminal of the AC power supply and flows through Q1, the detection circuit, and Q2 to the neutral wire terminal of the AC power supply. During the negative half-cycle, the second switching transistor Q2 is periodically switched on and off, while the first switching transistor Q1 remains off. The negative voltage is output from the neutral wire terminal of the AC power supply and flows through Q2, the detection circuit, and Q1 to the live wire terminal of the AC power supply.

[0078] Combination Figure 3A , Figure 3B and Figure 5 It is known that the detection circuit set between the source of the first switching transistor and the source of the second switching transistor can detect the AC power output of the AC power supply in the positive half-cycle and the negative half-cycle respectively, thereby completing the voltage detection of the AC power. Compared with the related technology of setting multiple sampling resistors for multiple power switching devices respectively, the embodiment of this application can reduce the number of sampling resistors, reduce device cost, and reduce board space.

[0079] In some embodiments, the detection circuit may include a sampling resistor, with one end of the sampling resistor connected to the source of the first switching transistor and the source of the second switching transistor, and the other end of the sampling resistor connected to the sampling port of the control circuit 103. Thus, the control circuit 103 can acquire the first voltage value at the sampling resistor through the sampling port, and then compare the first voltage value with a preset voltage to output a control signal.

[0080] In one embodiment, such as Figure 6 As shown, the detection circuit includes a first sampling resistor 1041, a first differential amplifier 1042, and a comparator 1043. The first sampling resistor 1041 is disposed between the source of the first switching transistor and the source of the second switching transistor, wherein:

[0081] The first input terminal of the first differential amplifier 1042 is connected to the first terminal of the first sampling resistor 1041, the second input terminal of the first differential amplifier 1042 is connected to the second terminal of the first sampling resistor 1041, and the output terminal of the first differential amplifier 1042 is connected to the first input terminal of the comparator 1043, for obtaining and obtaining the first voltage based on the voltage difference across the first sampling resistor 1041;

[0082] The first input terminal of comparator 1043 is connected to the output terminal of the first differential amplifier 1042, the second input terminal of comparator 1043 is connected to the reference power supply 1044, and the output terminal of comparator 1043 is connected to the control circuit 103 to obtain a first voltage and output a control signal according to the relationship between the first voltage and the preset voltage output by the reference power supply 1044.

[0083] During the detection process, when the alternating current passes through the first sampling resistor 1041, the differential amplifier collects the voltage across the first sampling resistor 1041 and outputs a first voltage based on the voltage difference across the first sampling resistor 1041. The comparator 1043 then outputs a control signal based on the relationship between the first voltage and the preset voltage output by the reference voltage.

[0084] In some embodiments, the first input terminal of the first differential amplifier 1042 can be a positive input terminal and the second input terminal can be a negative input terminal. The specific settings can be made by those skilled in the art according to the actual situation, and the embodiments of this application do not impose any restrictions.

[0085] For example, such as Figure 7 As shown, the detection circuit includes a sampling resistor R, a differential amplifier N1, and a comparator N2. The sampling resistor R is positioned between the sources of the first and second switching transistors. The negative input terminal of the differential amplifier N1 is connected to the first terminal of the sampling resistor R, and the positive input terminal of the differential amplifier N1 is connected to the second terminal of the sampling resistor R. The output terminal of the differential amplifier N1 is connected to the negative input terminal of the comparator N2. The differential amplifier N1 outputs a first voltage across the sampling resistor R, and the comparator N2 compares this first voltage with a preset voltage to output a control signal.

[0086] It is understandable that the first voltage sampled by the first sampling resistor 1041 is output to the comparator 1043 through the first differential amplifier 1042, so that the comparator 1043 outputs a control signal. The output of the control signal is implemented by hardware circuitry, which is lower in cost and more reliable than the method of outputting the control signal through the processor.

[0087] In one embodiment, such as Figure 8 As shown, the control signal includes a first signal and a second signal, the preset voltage includes a first threshold and a second threshold, and the comparator 1043 includes a first comparator 1043A and a second comparator 1043B, wherein:

[0088] The first comparator 1043A has its negative input terminal connected to the reference power supply 1044 via a first resistor, its non-inverting input terminal connected to the output terminal of the first differential amplifier 1042, and its output terminal connected to the control circuit 103. It is used to output a first signal based on the relationship between the first voltage and the first threshold.

[0089] The second comparator 1043B has its non-inverting input connected to the reference power supply 1044 via a second resistor, and its negative input connected to the output of the first differential amplifier 1042. The output of the second comparator 1043B is connected to the control circuit 103. It is used to output a second signal based on the relationship between the first voltage and the second threshold. The resistance values ​​of the first resistor and the second resistor are different.

[0090] During the detection process, the reference power supply 1044 can output a first threshold voltage to the negative input terminal of the first comparator 1043A through the first resistor, and the reference power supply 1044 can output a second threshold voltage to the positive input terminal of the second comparator 1043B through the second resistor. Thus, the first comparator 1043A can output a control signal indicating whether the first voltage is greater than the first threshold voltage, and the second comparator 1043B can output a control signal indicating whether the first voltage is less than the second threshold voltage. After receiving the two control signals, the control circuit 103 adjusts the DC power.

[0091] For example, the voltage of the reference power supply 1044 is 5V. The first threshold voltage obtained after the reference voltage is divided by the first resistor is 0.66V, and the second threshold voltage obtained after the reference voltage is divided by the second resistor is 4.34V. Then, when the first voltage Vout satisfies 0.66V≤Vout≤4.34V, the first comparator 1043A outputs a high level and the second comparator 1043B outputs a high level; when the first voltage Vout satisfies Vout≤0.66V, the first comparator 1043A outputs a low level and the second comparator 1043B outputs a high level; when the first voltage Vout satisfies 4.34V≤Vout, the first comparator 1043A outputs a high level and the second comparator 1043B outputs a low level.

[0092] In some embodiments, the controller 1031 can receive two control signals through different physical channels. For example, the controller 1031 includes a first port and a second port. The first port is connected to the first comparator 1043A and the second port is connected to the second comparator 1043B. Thus, the controller 1031 receives the control signal output by the first comparator 1043A through the first port and the control signal output by the second comparator 1043B through the second port.

[0093] In other embodiments, the two control signals output from the first comparator 1043A and the second comparator 1043B can be first ANDed using an AND logic module before the resulting control signal is output to the controller 1031, thereby reducing the computational resource consumption of the controller 1031. Specifically, the detection circuit also includes an AND logic gate circuit, with its first input connected to the first comparator 1043A, its second input connected to the second comparator 1043B, and its output connected to the control circuit 103.

[0094] For example, when the first comparator 1043A outputs a low level and the second comparator 1043B outputs a high level, a low-level signal is output to the control circuit 103 after passing through an AND logic gate.

[0095] Understandably, by setting two comparators 1043 to compare the first voltage, the preset voltage can be set to a range value, thereby improving the accuracy of the control signal output.

[0096] In one embodiment, such as Figure 9 As shown, the control circuit 103 includes a controller 1031 and a driver 1032, wherein:

[0097] The controller 1031 is connected to the driver 1032 and is used to output a drive signal. The drive signal is used to control the target switch to be turned on or off. The target switch includes a first switch and / or a second switch.

[0098] The driver 1032 includes an input terminal, an enable terminal, a first output terminal, and a second output terminal. The first output terminal is connected to the gate of a first switching transistor, and the second output terminal is connected to the gate of a second switching transistor. The input terminal is connected to a controller 1031, and the enable terminal is connected to a detection circuit. The driver is used to obtain a drive signal and, if the magnitude relationship between the first voltage and the preset voltage meets the operating conditions of the driver 1032, amplify the drive signal and output the processed drive signal to the target switching transistor. If the magnitude relationship between the first voltage and the preset voltage does not meet the operating conditions of the driver 1032, the driver signal is not amplified.

[0099] During the detection process, if the operating condition of the driver 1032 is that the first voltage is greater than the preset voltage, then after the comparator 1043 outputs the control signal to the driver 1032, the driver 1032 will determine whether to amplify the drive signal based on the relationship between the first voltage indicated by the control signal and the preset voltage. If the control signal indicates that the first voltage is greater than the preset voltage, then the driver 1032 will amplify the drive signal. If the control signal indicates that the first voltage is less than the preset voltage, then the driver 1032 will not amplify the drive signal, that is, it will not output the processed drive signal, thereby causing the first switch and the second switch to disconnect.

[0100] It is understandable that by setting the driver 1032 to amplify the drive signal output by the controller 1031, the requirements for the output voltage of the controller 1031 can be reduced, thereby reducing the cost of the device.

[0101] In one embodiment, the drive signal includes a first drive signal and a second drive signal, the input terminals of the driver 1032 include a first input terminal and a second input terminal, and the controller 1031 includes a first output terminal and a second output terminal, wherein:

[0102] The first output terminal of the controller 1031 is connected to the first input terminal of the driver 1032. The controller 1031 is used to output a first drive signal to drive the first switching transistor to turn on or off through the driver 1032.

[0103] The second output terminal of the controller 1031 is connected to the second input terminal of the driver 1032. The controller 1031 is used to output a second drive signal to drive the second switching transistor to turn on or off through the driver 1032.

[0104] During the detection process, the controller 1031 outputs a first drive signal to the first input terminal of the driver 1032 through the first output terminal, and outputs a second drive signal to the second input terminal of the driver 1032 through the second output terminal, thereby driving the first switch and the second switch to turn on or off respectively.

[0105] It is understandable that by connecting the two input terminals of the driver 1032 to the two output terminals of the controller 1031 respectively, the controller 1031 can output two drive signals to drive the two switching transistors respectively, thereby improving reliability.

[0106] In some embodiments, both the first drive signal and the second drive signal are PWM signals.

[0107] In one embodiment, such as Figure 10As shown, the input terminal of the controller 1031 is also connected to the output terminal of the detection circuit, and is used to output a drive signal indicating to disconnect the first and second switching transistors when the magnitude relationship between the first voltage and the preset voltage does not meet the operating conditions of the air conditioner.

[0108] It should be understood that if the relationship between the first voltage and the preset voltage does not meet the operating conditions of the air conditioner, continuing to output the first voltage may damage the load in the air conditioner. Therefore, when the control signal indicates that the first voltage is greater than the preset voltage, the controller 1031 can directly output a drive signal to disconnect both the first and second switching transistors according to the control signal, so that the power management module does not output DC power and avoids damage to the device.

[0109] For example, such as Figure 11 As shown, driver 1032 includes a first enable terminal ENA, a second enable terminal ENB, a first input terminal INA, a second input terminal INB, a first output terminal OUTA, and a second output terminal OUTB. Controller 1031 includes an input terminal IN, a first output terminal OUTA, and a second output terminal OUTB. The first enable terminal ENA and the second enable terminal ENB of driver 1032 are respectively connected to the output terminal of control circuit 103 for simultaneously receiving control signals. The first input terminal INA of driver 1032 is connected to the first output terminal OUTA of controller 1031, the second input terminal INB of driver 1032 is connected to the second output terminal OUTB of controller 1031, the first output terminal OUTA of driver 1032 is connected to the first switch Q1, the second output terminal OUTB of driver 1032 is connected to the second switch Q2, and the input terminal IN of controller 1031 is connected to the output terminal of control circuit 103. The first enable terminal ENA of driver 1032 drives the first output terminal OUTA, and the second enable terminal ENB of driver 1032 drives the second output terminal OUTB. The first output terminal OUTA and the second output terminal OUTB of driver 1032 are output independently.

[0110] When the first voltage is greater than the preset voltage, the detection circuit outputs a high-level signal; when the first voltage is less than the preset voltage, the detection circuit outputs a low-level signal. When the driver 1032 receives a low-level signal via the first enable terminal ENA and the second enable terminal ENB, it does not output the amplified drive signal via the first output terminal OUTA and the second output terminal OUTB. Similarly, when the controller 1031 receives a low-level signal via the input terminal IN, it continuously outputs two low-level signals via the first output terminal OUTA and the second output terminal OUTB, thereby achieving hardware protection.

[0111] When the driver 1032 receives a high-level signal through the first enable terminal ENA and the second enable terminal ENB, it amplifies the two drive signals received through the first input terminal INA and the second input terminal INB respectively. When the controller 1031 receives a high-level signal through the input terminal IN, it normally outputs the two drive signals through the first output terminal OUTA and the second output terminal OUTB.

[0112] It is understandable that by connecting the output of comparator 1043 to controller 1031, controller 1031 can disconnect the first and second switching transistors when the relationship between the first voltage and the preset voltage does not meet the operating conditions of the air conditioner, thereby preventing the power management module from outputting DC power and protecting the hardware safety of the air conditioner.

[0113] In one embodiment, such as Figure 12 As shown, the air conditioner also includes a sampling circuit 105. The first end of the sampling circuit 105 is connected to the detection circuit, the second end of the sampling circuit 105 is connected to the output capacitor, and the third end of the sampling circuit 105 is connected to the controller 1031. The sampling circuit 105 is used to obtain the second voltage at the input end of the output capacitor and output the second voltage to the controller 1031.

[0114] The controller 1031 is configured to output a drive signal indicating to disconnect the first and second switching transistors when the second voltage does not meet the operating conditions of the air conditioner. The operating conditions include the second voltage being within the operating voltage range.

[0115] During the testing process, if the second voltage does not meet the operating conditions of the air conditioner, continuing to output the second voltage may damage the load in the air conditioner. Therefore, when the second voltage is outside the operating voltage range, the controller 1031 can directly output a drive signal to disconnect both the first and second switching transistors, so that the power management module does not output DC power and avoids damage to the device.

[0116] It should be understood that Figure 12 and Figure 10 It can achieve the same function, but because Figure 10 The output of the detection circuit is connected to both the input of the driver 1032 and the input of the controller 1031. This may cause the output signal to deviate due to too many ports connected to the detection circuit, making it impossible for the controller 1031 and the driver 1032 to accurately determine the relationship between the second voltage and the preset voltage. Therefore, in this embodiment, an additional sampling circuit 105 is used to detect the second voltage at the input of the output capacitor so that the controller 1031 can accurately determine the second voltage.

[0117] It should be understood that, such as Figure 3AAs shown, when the switch Q1 is off, the AC power output from the live wire terminal passes through the inductor L, rectifier D1, output capacitor, and the body diode of the switch Q2 before being output to the neutral wire terminal. At this time, the input current does not pass through the first sampling resistor. Therefore, during the time period when the switch Q1 is off, the detection circuit cannot output for indication, resulting in a blank window period. At this time, the detection of the second voltage by the sampling circuit 105 can be combined to assist in realizing the adjustment output of the DC power of the power management module.

[0118] In some embodiments, after obtaining the second voltage, the controller 1031 can calculate the corresponding bus current value based on the device parameters of the sampling circuit 105, thereby detecting the bus current of the air conditioner.

[0119] In other embodiments, after obtaining the second voltage, the controller 1031 can adjust the DC current according to the magnitude of the second voltage. For example, when the second voltage is greater than the operating voltage threshold, the output DC current voltage and current are reduced; or, when the second voltage is less than the operating voltage threshold, the output DC current voltage and current are increased.

[0120] In one embodiment, such as Figure 13 As shown, the sampling circuit 105 may include a second sampling resistor 1051 and a second differential amplifier 1052, wherein:

[0121] The first input terminal of the second differential amplifier 1052 is connected to the first terminal of the second sampling resistor 1051, the second input terminal of the second differential amplifier 1052 is connected to the second terminal of the second sampling resistor 1051, and the output terminal of the second differential amplifier 1052 is connected to the control circuit 103. The output voltage is obtained based on the voltage difference across the second sampling resistor 1051, and the output voltage is output to the controller 1031.

[0122] During the detection process, when the AC current passes through the second sampling resistor 1051, the second differential amplifier 1052 collects the voltage across the two ends of the second sampling resistor 1051, and outputs the second voltage to the controller 1031 based on the voltage difference across the two ends of the second sampling resistor 1051.

[0123] It is understandable that by using the second differential amplifier 1052 to output the output voltage collected by the second sampling resistor 1051 to the controller 1031, the detection of the second voltage is realized by using hardware circuitry, which is lower in cost and more reliable.

[0124] In one embodiment, the resistance of the second sampling resistor 1051 is greater than the resistance of the first sampling resistor 1041.

[0125] It is understandable that setting the resistance of the second sampling resistor 1051 to a larger value can improve the accuracy of the output voltage calculation, while setting the resistance of the first sampling resistor 1041 to a smaller value can reduce the loss of AC power during transmission between the source of the first switching transistor and the source of the second switching transistor.

[0126] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0127] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0128] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0129] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0130] In addition, each functional module in the various embodiments of this application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the integrated modules can be implemented in hardware or in the form of hardware plus software functional units.

[0131] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0132] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An air conditioner characterized by comprising: The air conditioner comprises: a housing; a power management module arranged in the housing, an input end of the power management module being connected with an alternating current power supply, an output end of the power management module being connected with a load of the air conditioner, for obtaining alternating current output by the alternating current power supply and converting the alternating current into direct current to output to the load, so as to make the air conditioner work; wherein the power management module comprises: an alternating current input end comprising a first input end and a second input end, the first input end and the second input end having different polarities; a bridgeless PFC circuit comprising an inductor, a first switch tube, a second switch tube, a first rectifier tube, a second rectifier tube and an output capacitor, a first end of the inductor being connected with the first input end, a second end of the inductor being connected with a positive pole of the first rectifier tube and a drain of the first switch tube respectively, a drain of the second switch tube being connected with the second input end and a positive pole of the second rectifier tube respectively, a first end of the output capacitor being connected with a negative pole of the first rectifier tube and a negative pole of the second rectifier tube respectively, and a second end of the output capacitor being connected with a ground end, a source of the first switch tube and a source of the second switch tube respectively; a detection circuit, a first end of the detection circuit being connected with the source of the first switch tube, and a second end of the detection circuit being connected with the source of the second switch tube, the detection circuit being used for obtaining and outputting a control signal according to a first voltage between the source of the first switch tube and the source of the second switch tube, the control signal being used for indicating a size relationship between the first voltage and a preset voltage; a control circuit, an input end of the control circuit being connected with a third end of the detection circuit, and output ends of the control circuit being connected with a gate of the first switch tube and a gate of the second switch tube respectively, the control circuit being used for obtaining and controlling conduction or disconnection of the first switch tube and the second switch tube according to the control signal, so as to adjust a voltage value and / or a current value of the direct current.

2. The air conditioner of claim 1, wherein The detection circuit comprises a first sampling resistor, a first differential amplifier and a comparator, the first sampling resistor being arranged between the source of the first switch tube and the source of the second switch tube, wherein: a first input end of the first differential amplifier is connected with a first end of the first sampling resistor, a second input end of the first differential amplifier is connected with a second end of the first sampling resistor, and an output end of the first differential amplifier is connected with a first input end of the comparator, the first differential amplifier being used for obtaining the first voltage according to a voltage difference between the first end and the second end of the first sampling resistor; a first input end of the comparator is connected with the output end of the first differential amplifier, a second input end of the comparator is connected with a reference power supply, and an output end of the comparator is connected with the control circuit, the comparator being used for obtaining the first voltage and outputting the control signal according to a size relationship between the first voltage and a preset voltage output by the reference power supply.

3. The air conditioner of claim 2, wherein The control signal comprises a first signal and a second signal, the preset voltage comprises a first threshold value and a second threshold value, and the comparator comprises a first comparator and a second comparator, wherein: The first comparator, a negative phase input end of the first comparator is connected with a reference power supply through a first resistor, a positive phase input end of the first comparator is connected with an output end of the first differential amplifier, and an output end of the first comparator is connected with the control circuit, so as to output the first signal according to a size relationship between the first voltage and the first threshold value; The second comparator, a positive phase input end of the second comparator is connected with the reference power supply through a second resistor, a negative phase input end of the second comparator is connected with the output end of the first differential amplifier, and an output end of the second comparator is connected with the control circuit, so as to output the second signal according to a size relationship between the first voltage and the second threshold value, and the first resistor and the second resistor have different resistance values.

4. The air conditioner according to claim 2 or 3, wherein The control circuit comprises a controller and a driver, wherein: The controller is connected with the driver, so as to output a driving signal, the driving signal is used for controlling the target switch tube to be turned on or turned off, and the target switch tube comprises the first switch tube and / or the second switch tube; The driver comprises an input end, an enable end, a first output end and a second output end, the first output end is connected with a gate of the first switch tube, the second output end is connected with a gate of the second switch tube, the input end is connected with the controller, and the enable end is connected with the detection circuit, so as to obtain the driving signal, and in the case that the size relationship between the first voltage and the preset voltage meets the working condition of the driver, the driving signal is amplified and processed, and the processed driving signal is output to the target switch tube.

5. The air conditioner of claim 4, wherein The driving signal comprises a first driving signal and a second driving signal, the input end of the driver comprises a first input end and a second input end, and the controller comprises a first output end and a second output end, wherein: The first output end of the controller is connected with the first input end of the driver, and the controller is used for outputting the first driving signal, so as to drive the first switch tube to be turned on or turned off through the driver; The second output end of the controller is connected with the second input end of the driver, and the controller is used for outputting the second driving signal, so as to drive the second switch tube to be turned on or turned off through the driver.

6. The air conditioner of claim 5, wherein The first driving signal and the second driving signal are both PWM signals.

7. The air conditioner of claim 4, wherein The input end of the controller is also connected with the output end of the comparator, so as to output a driving signal indicating that the first switch tube and the second switch tube are turned off, in the case that the size relationship between the first voltage and the preset voltage does not meet the working condition of the air conditioner.

8. The air conditioner of claim 2, wherein The air conditioner further comprises a sampling circuit, an input end of the sampling circuit is connected with the output capacitor, and an output end of the sampling circuit is connected with the detection circuit, so as to obtain a second voltage at the input end of the output capacitor and output the second voltage to the control circuit, so that the control circuit adjusts the direct current according to the second voltage.

9. The air conditioner of claim 8, wherein The sampling circuit comprises a second sampling resistor and a second differential amplifier, a first end of the second sampling resistor is connected with the output capacitor, and a second end of the second sampling resistor is respectively connected with the detection circuit and a source electrode of the second switch tube. A first input end of the second differential amplifier is connected with the first end of the second sampling resistor, a second input end of the second differential amplifier is connected with the second end of the second sampling resistor, and an output end of the second differential amplifier is connected with the control circuit, so as to obtain the second voltage according to a voltage difference between two ends of the second sampling resistor and output the second voltage to the control circuit.

10. The air conditioner of claim 9, wherein The resistance value of the second sampling resistor is greater than the resistance value of the first sampling resistor.

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