A multi-connected air conditioner and a control method thereof

Abstract

The embodiment of the application provides a multi-connected air conditioner and a control method, and relates to the technical field of electrical appliances. In the air conditioner, the electric energy converted by instant stop of the fan provides stable voltage for closing the electronic expansion valve. The air conditioner comprises a power supply circuit, an energy storage circuit, a voltage transmission circuit, a driving chip, a main control chip, a fan unit and an electronic expansion valve; the energy storage circuit is electrically connected with the power supply circuit, the fan unit and the voltage transmission circuit; the voltage transmission circuit is further electrically connected with the main control chip and the electronic expansion valve; the main control chip is electrically connected with the electronic expansion valve; the energy storage circuit recovers and stores the electric energy generated by the rotational inertia of the fan unit during instant stop when the power supply circuit stops supplying power, and provides electric energy for the voltage transmission circuit; the voltage transmission circuit generates the working voltage required by the main control chip and the electronic expansion valve based on the electric energy provided by the energy storage circuit, and transmits the working voltage to the main control chip and the electronic expansion valve; and the main control chip is configured to control the electronic expansion valve to be closed.

Description

Technical Field

[0001] This invention relates to the field of electrical technology, and in particular to a multi-split air conditioner and its control method. Background Technology

[0002] With the development of science and technology, air conditioning is becoming more and more common, and more and more people's daily lives are closely related to air conditioning.

[0003] Currently, multi-split air conditioners typically consist of one or more outdoor units connected to several direct evaporation indoor units of different or identical types and capacities, forming a single refrigeration cycle system. They are characterized by their small footprint and are widely used in residential, commercial, and public buildings.

[0004] As a crucial component of multi-split air conditioners, the electronic expansion valve controls the refrigerant flow by adjusting its opening degree, thereby controlling the indoor temperature. In multi-split air conditioners connected to the outdoor unit, if some indoor units are powered off, the electronic expansion valve typically remains open as it was when the power was off. If the electronic expansion valve is not fully closed, the refrigerant will continue to flow through the pipes of the unpowered indoor units. Due to the lack of energy exchange, the refrigerant cannot effectively evaporate or cool, easily causing malfunctions in the multi-split air conditioner. Summary of the Invention

[0005] This invention provides a multi-split air conditioner and a control method to solve the problem that the electronic expansion valve of a multi-split air conditioner cannot close due to insufficient power after the indoor unit is powered off.

[0006] Firstly, the air conditioner includes an indoor unit, which includes a power supply circuit, an energy storage circuit, a voltage transmission circuit, a drive chip, a main control chip, a fan unit, and an electronic expansion valve.

[0007] The power supply circuit is electrically connected to the first end of the energy storage circuit, the first end of the energy storage circuit is also electrically connected to the fan unit and the voltage transmission circuit, and the second end of the energy storage circuit is grounded; the voltage transmission circuit is also electrically connected to the main control chip and the electronic expansion valve; the main control chip is also electrically connected to the fan unit and the drive chip; the drive chip is also electrically connected to the electronic expansion valve.

[0008] The main control chip is configured to control the fan unit to stop momentarily when the power supply circuit stops supplying power; the energy storage circuit is configured to recover and store the electrical energy generated by the rotational inertia of the fan unit during the momentary stop when the power supply circuit stops supplying power, and to provide power to the voltage transmission circuit; the voltage transmission circuit can generate the operating voltage required by the main control chip and the electronic expansion valve based on the electrical energy provided by the energy storage circuit, and transmit the operating voltage to the main control chip and the electronic expansion valve; the main control chip is configured to control the electronic expansion valve to close.

[0009] Based on the above technical solutions, in some embodiments of the present invention, the rotational inertia recovered by the momentary stop of the fan unit in a multi-split air conditioner is used to continue charging the energy storage circuit. This compensates for insufficient charging energy in the energy storage circuit and provides sufficient energy for the electronic expansion valve to close, thereby reducing circuit costs. Simultaneously, the multi-split air conditioner, through a voltage transmission circuit, can provide a stable operating voltage to the main control chip after the indoor unit is powered off, thus enabling the main control chip to control the electronic expansion valve to close.

[0010] In some embodiments, the energy storage circuit includes a capacitor, a first terminal of which is electrically connected to the power supply circuit, the voltage transmission circuit, and the wind turbine unit, and a second terminal of which is grounded.

[0011] In some embodiments, the wind turbine unit includes: a wind turbine and a wind turbine drive unit; the main control chip further includes a second control terminal; a first end of the wind turbine is electrically connected to a first end of the energy storage circuit, a second end of the wind turbine is electrically connected to a first end of the wind turbine unit, and a second end of the wind turbine unit is electrically connected to a second control terminal of the main control chip; the main control chip is configured to issue instructions to the wind turbine drive unit to cause the wind turbine drive unit to control the wind turbine to stop momentarily.

[0012] In some embodiments, the voltage transmission circuit includes a switching transformer, a rectifier circuit, a switching circuit, and a voltage conversion circuit; the main control chip includes a power supply terminal.

[0013] The input terminal of the switching transformer is electrically connected to the energy storage circuit, the output terminal of the switching transformer is electrically connected to the rectifier circuit, the rectifier circuit is electrically connected to the switching circuit, the switching circuit is electrically connected to the voltage conversion circuit, and the voltage conversion circuit is electrically connected to the power supply terminal of the main control chip.

[0014] In some embodiments,

[0015] The switching transformer includes a first input terminal, a second input terminal, a first output terminal, and a second output terminal; the rectifier circuit includes a first rectifier circuit and a second rectifier circuit; the switching circuit includes a first input terminal, a second input terminal, an output terminal, and a control terminal; the voltage conversion circuit includes an input terminal and an output terminal; and the main control chip also includes a first control terminal.

[0016] The first and second input terminals of the switching transformer are electrically connected to the first and second terminals of the energy storage circuit, respectively; the first output terminal of the switching transformer is electrically connected to the first rectifier circuit, and the second output terminal of the switching transformer is electrically connected to the second rectifier circuit; the first input terminal of the switching circuit is electrically connected to the first rectifier circuit, and the second input terminal of the switching circuit is electrically connected to the second rectifier circuit; the control terminal of the switching circuit is electrically connected to the first control terminal of the main control chip, and the output terminal of the switching circuit is electrically connected to the input terminal of the voltage conversion circuit and the power supply terminal of the electronic expansion valve; the output terminal of the voltage conversion circuit is electrically connected to the power supply terminal of the main control chip.

[0017] In some embodiments, the voltage transmission circuit further includes a first resistor and a Zener diode, and the multi-split air conditioner further includes a wired controller; a first terminal of the first resistor is electrically connected to the second rectifier circuit, and a second terminal of the first resistor is electrically connected to the second input terminal of the switching circuit; the positive terminal of the Zener diode is grounded, and the negative terminal of the Zener diode is electrically connected to the second terminal of the first resistor; the wired controller is electrically connected to the first terminal of the first resistor.

[0018] In some embodiments, the voltage transmission circuit further includes a second resistor and a third resistor; the main control chip further includes a voltage acquisition terminal;

[0019] The first end of the second resistor is electrically connected to the output end of the switching circuit, the second end of the second resistor is electrically connected to the first end of the third resistor, the second end of the second resistor is also electrically connected to the voltage acquisition end of the main control chip, and the second end of the third resistor is grounded.

[0020] The main control chip is also configured to determine whether the indoor unit is powered off: if the absolute value of the difference between the voltage value acquired by the voltage acquisition terminal and the reference voltage value is less than or equal to a threshold, the main control chip determines that the indoor unit is not powered off; if the absolute value of the difference between the voltage value acquired by the voltage acquisition terminal and the reference voltage value is greater than the threshold, the main control chip determines that the indoor unit is powered off.

[0021] In some embodiments, the indoor unit further includes a driver chip, which includes multiple input terminals, multiple output terminals, and a ground terminal; the main control chip further includes multiple output terminals.

[0022] The multiple input terminals of the driver chip are connected one-to-one with the multiple output terminals of the main control chip, and the multiple output terminals of the driver chip are electrically connected one-to-one with the multiple input terminals of the electronic expansion valve; the ground terminal of the driver chip is grounded.

[0023] The driver chip is configured to receive instructions from the main control chip and close the electronic expansion valve.

[0024] Secondly, the control method of this invention is as follows:

[0025] When the power supply circuit stops supplying power, the main control chip sends a second control command to the fan unit; the fan unit stops momentarily according to the second control command; the energy storage circuit recovers and stores the electrical energy generated by the fan unit during the momentary stop; the voltage transmission circuit generates the operating voltage required by the main control chip and the electronic expansion valve based on the electrical energy provided by the energy storage circuit, and transmits the operating voltage to the main control chip and the electronic expansion valve; the main control chip sends a third control command to the drive chip; the drive chip controls the electronic expansion valve to close according to the third control command.

[0026] The beneficial effects of the control method in the second aspect are the same as those of the multi-split air conditioner mentioned above, and will not be repeated here.

[0027] In some embodiments, the voltage transmission circuit includes a switching transformer, a rectifier circuit, a switching circuit, and a voltage conversion circuit; the rectifier circuit includes a first rectifier circuit and a second rectifier circuit; the switching circuit includes a first input terminal, a second input terminal, an output terminal, and a control terminal.

[0028] When the power supply circuit stops supplying power, the control method further includes: the main control chip issuing a first control command to the switching circuit; the switching circuit electrically connecting its second input terminal and output terminal according to the first control command; and the voltage transmission circuit generating the operating voltage required by the main control chip and the electronic expansion valve based on the electrical energy provided by the energy storage circuit, and transmitting the operating voltage to the main control chip and the electronic expansion valve, including: the voltage transmission circuit generating the operating voltage required by the main control chip and the electronic expansion valve based on the electrical energy provided by the energy storage circuit, through the switching transformer, the second rectifier circuit, the path between the second input terminal and the output terminal of the switching circuit, and the voltage conversion circuit, and transmitting the operating voltage to the main control chip and the electronic expansion valve. Attached Figure Description

[0029] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0030] Figure 1 A system block diagram of an indoor unit provided in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of a voltage transmission circuit provided in an embodiment of the present invention;

[0032] Figure 3 A system block diagram of a power supply circuit provided in an embodiment of the present invention;

[0033] Figure 4 A partial circuit diagram of an indoor unit provided in an embodiment of the present invention;

[0034] Figure 5 A partial circuit diagram of another indoor unit provided in an embodiment of the present invention;

[0035] Figure 6 An overall circuit diagram of an indoor unit provided in an embodiment of the present invention;

[0036] Figure 7 A circuit diagram of an indoor unit and a wired controller provided in an embodiment of the present invention;

[0037] Figure 8 A flowchart of control instructions for a main control chip is provided as an embodiment of the present invention;

[0038] Figure 9 Another control instruction flowchart for the main control chip provided in this embodiment of the invention;

[0039] Figure 10 This is a flowchart of a main control chip control instruction provided in an embodiment of the present invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, when describing pipelines, the terms "connected" and "linked" as used in this invention have the meaning of enabling conduction. The specific meaning needs to be understood in conjunction with the context.

[0044] In embodiments of the present invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0045] As described in the background section, electronic expansion valves, as an important component of multi-split air conditioners, control the refrigerant flow by adjusting their opening degree, thereby controlling indoor temperature. In multi-split air conditioners connected to an outdoor unit, if some indoor units are powered off, the electronic expansion valve's opening degree is generally the same as when the indoor units were powered off. If the electronic expansion valve is not completely closed, the refrigerant will continue to flow in the pipes of the unpowered indoor units. Due to the lack of energy exchange, the refrigerant cannot effectively evaporate or cool, easily causing multi-split air conditioner malfunctions.

[0046] Based on this, embodiments of the present invention provide a multi-split air conditioner. The multi-split air conditioner includes: an indoor unit 500 and an outdoor unit; as shown... Figure 1 As shown, the indoor unit 500 includes: a power supply circuit 100, an energy storage circuit 200, a voltage transmission circuit 300, a fan unit 400, a main control chip 13, and an electronic expansion valve 15.

[0047] The power supply circuit 100 is electrically connected to the first terminal 211 of the energy storage circuit 200. The first terminal 211 of the energy storage circuit 200 is also electrically connected to the fan unit 400 and the voltage transmission circuit 300. The second terminal 212 of the energy storage circuit 200 is grounded. The voltage transmission circuit 300 is also electrically connected to the main control chip 13 and the electronic expansion valve 15. The main control chip 13 is also electrically connected to the fan unit 400 and the drive chip 14. The drive chip 14 is also electrically connected to the electronic expansion valve 15.

[0048] The main control chip 13 is configured to control the fan unit 400 to stop momentarily when the power supply circuit 100 stops supplying power; the energy storage circuit 200 is configured to recover and store the electrical energy generated by the rotational inertia of the fan unit 400 during the momentary stop when the power supply circuit 100 stops supplying power, and to provide power to the voltage transmission circuit 300; the voltage transmission circuit 300 can generate the operating voltage required by the main control chip 13 and the electronic expansion valve 15, and transmit the operating voltage to the main control chip 13 and the electronic expansion valve 15; the main control chip 13 is configured to control the electronic expansion valve 15 to close.

[0049] It should be noted that the power supply circuit 100 stops supplying power in the following situations: indoor unit 500 loses power. Indoor unit 500 losing power means that the indoor unit 500 is manually disconnected from the power supply or that the power supply circuit 100 fails, resulting in the indoor unit 500 losing power.

[0050] When the power supply circuit 100 stops supplying power, the energy storage circuit 200 provides power to the voltage transmission circuit 300. The voltage transmission circuit 300 transmits the power to the main control chip 13 and the electronic expansion valve 15, providing power to both. After determining that the indoor unit has lost power, the main control chip 13 sends a command to the fan unit 400 to stop operation momentarily and a command to close the electronic expansion valve 15. The electrical energy generated by the rotational inertia of the fan unit 400 during the momentary stop is stored in the energy storage circuit 200. The energy storage circuit 200 continues to provide power to the main control chip 13 via the voltage transmission circuit 300, providing sufficient energy for the electronic expansion valve 15 to close. The main control chip 13 then issues a command to close the electronic expansion valve 15.

[0051] It should be noted that during the operation of the indoor unit 500, the power supply circuit 100 provides electrical energy to the various components within the indoor unit, and the energy storage circuit 200 continuously stores and releases electrical energy; this process is referred to as the charging and discharging process of the energy storage circuit (see reference). Figure 4 When the indoor unit 500 loses power, that is, when the power supply circuit 100 stops supplying power, the energy storage circuit 200 stores a portion of electrical energy. This electrical energy can support the main control chip 13 to issue a command to stop the fan unit 400, but it cannot support the subsequent control command of the main control chip 13 to close the electronic expansion valve 15.

[0052] Replacing the energy storage circuit 200 with a more powerful energy storage circuit would allow the control command of the main control chip 13 to close the electronic expansion valve 15 to continue, but it would increase circuit costs and is not suitable for this invention. Therefore, the electrical energy required for the control command of the main control chip 13 to close the electronic expansion valve 15 is the electrical energy converted from the rotational inertia generated when the fan unit 400 stops momentarily. The electrical energy provided by the fan unit 400 to the capacitor can continue to provide power to the main control chip 13 and the electronic expansion valve 15 for a period of time until the electronic expansion valve 15 closes (see reference). Figure 5 ).

[0053] In some embodiments of the present invention, the rotational inertia recovered by the momentary stop of the fan unit 400 in the multi-split air conditioner is used to continue charging the energy storage circuit 200. This compensates for insufficient charging energy in the energy storage circuit 200 and provides sufficient energy for the electronic expansion valve 15 to close, thereby reducing circuit costs. Simultaneously, the multi-split air conditioner, through the voltage transmission circuit 300, can provide a stable operating voltage to the main control chip 13 and the electronic expansion valve 15 after the indoor unit is powered off, thus enabling the main control chip 13 to control the electronic expansion valve 15 to close.

[0054] Energy storage circuit 200 includes capacitor 5 (refer to...) Figure 7 The first end of capacitor 5 is electrically connected to the power supply circuit 100, the voltage transmission circuit 300 and the fan unit 400, and the second end of capacitor 5 is grounded.

[0055] In some embodiments, the capacitor 5 is an electrolytic capacitor, that is, the positive terminal of the electrolytic capacitor is electrically connected to the power supply circuit 100, the voltage transmission circuit 300 and the fan unit 400, and the negative terminal of the electrolytic capacitor is grounded.

[0056] It should be noted that an electrolytic capacitor is a type of capacitor. The metal foil is the positive electrode, and the oxide film in close contact with the metal is the dielectric. The cathode is composed of conductive material, electrolyte, and other materials. Because the electrolyte is the main component of the cathode, it is named an electrolytic capacitor. Furthermore, the positive and negative terminals of an electrolytic capacitor must not be connected incorrectly.

[0057] Optionally, electrolytic capacitors have a very large capacitance per unit volume, tens to hundreds of times larger than other types of capacitors. Rated capacitance can be extremely high, easily reaching tens of thousands of μF or even several F. They have an overwhelming price advantage over other types because electrolytic capacitors are made from common industrial materials, such as aluminum. The equipment used to manufacture electrolytic capacitors is also common industrial equipment, allowing for large-scale production at relatively low cost.

[0058] In power supply circuits, electrolytic capacitors are typically used after the rectifier circuit to convert AC to DC. A relatively large electrolytic capacitor is connected after the rectifier circuit, utilizing its charging and discharging characteristics to transform the pulsating DC voltage after rectification into a relatively stable DC voltage. Thus, the electrolytic capacitor can serve as an energy storage element.

[0059] The aforementioned fan unit 400 includes: a fan 16 and a fan drive unit 17; the main control chip 13 also includes a second control terminal A1.

[0060] The first terminal of the fan 16 is electrically connected to the first terminal of the capacitor 5, and the second terminal of the fan 16 is electrically connected to the first terminal of the fan drive unit 17. The second terminal of the fan drive unit 17 is electrically connected to the second control terminal A1 of the main control chip 13. The electrical energy generated when the fan unit 400 stops momentarily is generated by recovering the rotational inertia of the fan 16 after it stops. The main control chip 13 is configured to send commands to the fan drive unit 17 to control the fan 16 to stop momentarily.

[0061] It should be noted that the instantaneous stop of the fan unit 400 refers to the sudden stop of the fan 16 under the drive of the fan drive unit 17. The fan drive unit 17 performs the instantaneous stop of the fan 16 by receiving the instruction from the main control chip 13.

[0062] Only under the above conditions will the electrical energy generated by the rotational inertia of the fan 16 be at its maximum. If the fan unit 400 stops naturally instead of under the control of the main control chip 13, the electrical energy generated by the rotational inertia will be reduced, which is not conducive to subsequent operation.

[0063] like Figure 2 As shown, the voltage transmission circuit 300 includes a switching transformer 6, a rectifier circuit, a switching circuit 11, and a voltage conversion circuit 12; (Refer to...) Figures 4-7 The main control chip 13 includes: a first control terminal I / O, a second control terminal A1, a voltage acquisition terminal ADC, multiple output terminals OUT13, a power supply terminal VCC, and a ground terminal GND.

[0064] The input terminal of the switching transformer 6 is electrically connected to the energy storage circuit 200, the output terminal of the switching transformer 6 is electrically connected to the rectifier circuit 7, the rectifier circuit 7 is electrically connected to the switching circuit 11, the switching circuit 11 is electrically connected to the voltage conversion circuit 12, and the voltage conversion circuit 12 is electrically connected to the power supply terminal VCC of the main control chip 13.

[0065] It should be noted that the switching transformer 6 is a power transformer with a switching transistor added. In addition to the voltage transformation function of a regular transformer, it also has the functions of insulation isolation and power transmission.

[0066] The function of rectifier circuit 7 is to convert AC voltage into DC voltage. The rectifier circuit is mainly composed of rectifier diodes.

[0067] like Figures 4-7 As shown, in some embodiments, the switching transformer 6 includes a first input terminal 611, a second input terminal 612, a first output terminal 613, a second output terminal 614, and a ground terminal GND, and the rectifier circuit 7 includes a first rectifier circuit 71 and a second rectifier circuit 72.

[0068] The electronic expansion valve 15 includes: a first input terminal IN151, a second input terminal IN152, a third input terminal IN153, a fourth input terminal IN154, a fifth input terminal IN155, and a sixth input terminal IN156.

[0069] The first input terminal 611 and the second input terminal 612 of the switching transformer 6 are electrically connected to the first terminal and the second terminal of the capacitor 5, respectively; the first output terminal 613 of the switching transformer 6 is electrically connected to the first rectifier circuit 71, and the second output terminal 614 of the switching transformer is electrically connected to the second rectifier circuit 72; both the first rectifier circuit 71 and the second rectifier circuit 72 are electrically connected to the switching circuit 11, and the switching circuit 11 is electrically connected to the voltage conversion circuit 12.

[0070] It should be noted that, for example, 11 to 12 in the accompanying drawings of this application indicate that component 11 belongs to component 12, and 71 to 7 indicate that the first rectifier circuit 71 belongs to rectifier circuit 7. That is, 71 is both the first rectifier circuit and the rectifier circuit. Other similar reference numerals in the accompanying drawings also follow the above description.

[0071] like Figures 4-7 As shown, in some embodiments, the switching circuit 11 includes a first input terminal IN1, a second input terminal IN2, an output terminal OUT11, and a control terminal A; the voltage conversion circuit 12 includes an input terminal IN12 and an output terminal OUT12.

[0072] The first input terminal IN1 of the switching circuit 11 is electrically connected to the first rectifier circuit 71, and the second input terminal IN2 of the switching circuit 11 is electrically connected to the second rectifier circuit 72. The control terminal A of the switching circuit 11 is electrically connected to the first control terminal I / O of the main control chip 13. The output terminal OUT11 of the switching circuit 11 is electrically connected to the voltage conversion circuit 12, and the fifth input terminal IN155 and the sixth input terminal IN156 of the electronic expansion valve 15. The output terminal OUT12 of the voltage conversion circuit 12 is electrically connected to the power supply terminal VCC of the main control chip 13.

[0073] like Figure 6 As shown, the voltage transmission circuit 300 also includes a first resistor 9 and a Zener diode 10; as Figure 7 As shown, the multi-split air conditioner also includes a wired controller 18.

[0074] The first end of the first resistor 9 is electrically connected to the second rectifier circuit 72, and the second end of the first resistor 9 is electrically connected to the second input terminal IN2 of the switch circuit 11; the positive terminal of the Zener diode 10 is grounded, and the negative terminal of the Zener diode 10 is electrically connected to the second end of the first resistor 9; the wired controller 18 is electrically connected to the first end of the first resistor 9.

[0075] It should be noted that after the indoor unit 500 is powered off, the electrical energy generated by the momentary stop of the fan unit 400 is stored in capacitor 5. This electrical energy enables the first rectifier circuit 71 to output a +12V voltage and the second rectifier circuit 72 to output a +17V voltage. The output voltage of the second rectifier circuit can provide a +17V voltage for the normal operation of the air conditioner remote controller 18. The first resistor 9 serves as a current limiter, protecting the Zener diode 10, and the voltage drop across the first resistor 9 is less than 5V. The breakdown voltage of the Zener diode 10 is preferably +12V.

[0076] like Figure 6 As shown, the voltage transmission circuit 300 also includes a second resistor 19 and a third resistor 20; the first end of the second resistor 19 is electrically connected to the output terminal OUT11 of the switching circuit 11, the second end of the second resistor 19 is electrically connected to the first end of the third resistor 20, the second end of the second resistor 19 is also electrically connected to the voltage acquisition terminal ADC of the main control chip 13, and the second end of the third resistor 20 is grounded.

[0077] The main control chip 13 is also configured to determine whether the indoor unit is powered off: if the voltage acquisition terminal obtains the acquired voltage value V AD With reference voltage value V R If the absolute value of the difference between the two values ​​is less than or equal to the threshold, the main control chip 13 determines that the indoor unit 500 is not powered off; if the voltage value V obtained by the voltage acquisition terminal is... AD With reference voltage value V R The absolute value of the difference between them is greater than the threshold V T The main control chip 13 determines that the indoor unit has lost power at 500.

[0078] It should be noted that the collected voltage value V AD The main control chip 13 acquires the voltage division value of the third resistor 20; the reference voltage value V R When the indoor unit is being powered normally, the voltage value V is collected. AD The average value over time T; threshold V T When the indoor unit is being powered normally, the voltage value V is collected. AD Twice the standard deviation over time T.

[0079] In some embodiments, the ratio of the second resistor 19 to the third resistor 20 should be greater than or equal to 3:1, but the determination of whether the indoor unit is powered off depends on the collected voltage value V. AD With reference voltage value VR The deviation, the ratio of the second resistor 19 to the third resistor 20 will affect the acquired voltage value V. AD If the reference voltage value V is changed R Therefore, it is necessary to simultaneously change the ratio of the second resistor 19 to the third resistor 20. In other words, the ratio of the second resistor 19 to the third resistor 20 depends on how the reference voltage value V is changed. R .

[0080] Among them, the collected voltage value V AD With reference voltage value V R The deviation between them is ΔV = V AD -V R The absolute value of the deviation is |△V|.

[0081] If the absolute value of the deviation exceeds the threshold V T That is, |△V|>V T At this time, the indoor unit loses power.

[0082] If the absolute value of the deviation does not exceed the threshold V T That is, it satisfies |△V|≤V T At this time, the indoor unit was still powered on.

[0083] In some embodiments, the indoor unit further includes a driver chip 14, which includes multiple input terminals IN14, multiple output terminals OUT14, and a ground terminal GND.

[0084] Multiple input terminals IN14 of the driver chip 14 are connected one-to-one with multiple output terminals OUT13 of the main control chip 13, and multiple output terminals OUT14 of the driver chip 14 are electrically connected one-to-one with multiple input terminals of the electronic expansion valve 15; the ground terminal GND of the driver chip 14 is grounded.

[0085] It should be noted that the multiple output terminals OUT14 of the driver chip 14 are electrically connected to the multiple input terminals of the electronic expansion valve 15 in a one-to-one correspondence. Specifically, the multiple input terminals of the electronic expansion valve 15 refer to the first input terminal IN151, the second input terminal IN152, the third input terminal IN153, and the fourth input terminal IN154.

[0086] The driver chip 14 is configured to receive instructions from the main control chip 13 and close the electronic expansion valve 15.

[0087] like Figure 3 As shown, the power supply circuit 100 includes: a power supply 1, a fourth resistor 4, a differential-mode and common-mode rejection circuit 2, and a full-wave rectifier circuit 3;

[0088] Reference Figure 6 and Figure 7The power supply 1 is electrically connected to the input terminal of the differential-mode and common-mode suppression circuit 2. The output terminal of the differential-mode and common-mode suppression circuit 2 is electrically connected to the input terminal of the full-wave rectifier circuit 3. The output terminal of the full-wave rectifier circuit 3 is electrically connected to the first terminal of the fourth resistor 4. The second terminal of the fourth resistor 4 is electrically connected to the first terminal of the capacitor 5.

[0089] It should be noted that interference between any two power lines or communication lines can be represented by common-mode interference and differential-mode interference: Common-mode interference propagates between the conductor and ground and is asymmetrical interference; it is defined as an undesirable potential difference between any current-carrying conductor and the reference ground. Differential-mode interference propagates between two conductors and is symmetrical interference; it is defined as an undesirable potential difference between any two current-carrying conductors. Generally, common-mode interference has a larger amplitude and higher frequency, and can also radiate through the conductor, causing greater interference. Differential-mode interference has a smaller amplitude and lower frequency, causing less interference.

[0090] The aforementioned differential-mode and common-mode suppression circuit is configured to reduce common-mode interference and differential-mode interference. Generally, this is achieved by filtering to remove interference. In some embodiments, common-mode interference can also be reduced by shielding the signal lines and laying a large area of ​​ground on the PCB to reduce the ground impedance.

[0091] In summary, referring to Figure 6 and Figure 7 The specific circuit connection method of the electronic expansion valve closing circuit of the indoor unit is as follows:

[0092] Power supply 1 is electrically connected to the input terminal of differential-mode and common-mode suppression circuit 2. The output terminal of differential-mode and common-mode suppression circuit 2 is electrically connected to the input terminal of full-wave rectifier circuit 3. The output terminal of full-wave rectifier circuit 3 is electrically connected to the first terminal of fourth resistor 4. The second terminal of fourth resistor 4 is electrically connected to the first terminal of capacitor 5.

[0093] The first end of capacitor 5 is electrically connected to the first end of fan 16, and the second end of capacitor 5 is grounded. At the same time, the first end of capacitor 5 is electrically connected to the first input terminal 611 of switching transformer 6, the second end of capacitor 5 is electrically connected to the second input terminal 612 of switching transformer 6, the first output terminal 613 of switching transformer 6 is electrically connected to one end of the first rectifier circuit 71, and the second output terminal 614 of switching transformer 6 is electrically connected to one end of the second rectifier circuit 72.

[0094] The other end of the first rectifier circuit 71 is electrically connected to the first input terminal IN1 of the switch circuit 11. The other end of the second rectifier circuit 72 is electrically connected to the first terminal of the first resistor 9, and the other end of the second rectifier circuit 72 is electrically connected to the wired controller 18 to provide a stable operating voltage for the wired controller. The second terminal of the first resistor 9 is electrically connected to the second input terminal IN2 of the switch circuit 11, and the second terminal of the first resistor 9 is electrically connected to the negative terminal of the Zener diode 10. The positive terminal of the Zener diode 10 is grounded.

[0095] The control terminal A of the switching circuit 11 is electrically connected to the first control terminal I / O of the main control chip 13. The output terminal OUT11 of the switching circuit 11 is electrically connected to the input terminal IN12 of the voltage conversion circuit 12. At the same time, the output terminal OUT11 of the switching circuit 11 is electrically connected to the fifth input terminal IN155 and the sixth input terminal IN156 of the electronic expansion valve 15.

[0096] The first end of the second resistor 19 is electrically connected to the output terminal OUT11 of the switching circuit 11, the second end of the second resistor 19 is electrically connected to the first end of the third resistor 20, and the second end of the second resistor 19 is electrically connected to the voltage acquisition terminal ADC of the main control chip 13. The second end of the third resistor 20 is grounded.

[0097] The output terminal OUT12 of the voltage conversion circuit 12 is electrically connected to the power supply terminal VCC of the main control chip 13, and the ground terminal GND of the voltage conversion circuit 12 is grounded.

[0098] Multiple input terminals IN14 of the driver chip 14 are connected one-to-one with multiple output terminals OUT13 of the main control chip 13. Multiple output terminals OUT14 of the driver chip 14 are electrically connected to multiple input terminals of the electronic expansion valve 15. The ground terminal GND of the driver chip 14 is grounded.

[0099] The first end of the fan 16 is electrically connected to the first end of the capacitor 5, the second end of the fan 16 is electrically connected to the first end of the fan drive unit 17, and the second end of the fan drive unit 17 is electrically connected to the second control terminal A1 of the main control chip 13.

[0100] The specific operation process of the indoor unit 500 is as follows:

[0101] When the indoor unit 500 is not powered off, power supply 1 removes electromagnetic interference through differential-mode and common-mode rejection circuit 2, and converts AC to DC through full-wave rectifier circuit 3. Then, the voltage is output as +12V through switching transformer 6 and first rectifier circuit 71. At this time, switching circuit 11 is in the state where the first input terminal IN1 is connected and the second input terminal IN2 is disconnected. The +12V voltage is input through the first input terminal IN1 of switching circuit 11, and then electrically connected to the fifth input terminal IN155 and the sixth input terminal IN156 of electronic expansion valve 15 through the output terminal OUT11 of switching circuit 11, providing +12V voltage to electronic expansion valve 15. The output terminal OUT11 of switching circuit 11 is electrically connected to the input terminal IN12 of voltage conversion circuit 12, and the output terminal OUT12 of voltage conversion circuit 12 generates +5V voltage. The output terminal OUT12 of voltage conversion circuit 12 is electrically connected to the power supply terminal VCC of main control chip 13, providing voltage to main control chip 13.

[0102] It should be noted that at this time, the first input terminal IN1 of the switching circuit 11 is electrically connected to the output terminal OUT11 (refer to...). Figure 4 ).

[0103] When the indoor unit 500 is powered off, power supply 1 cannot provide voltage to the indoor unit 500. Capacitor 5 will discharge to provide power to the main control chip 13. The main control chip 13 sends a first control command to the switching circuit 11. At this time, the second input terminal IN2 and the output terminal OUT11 of the switching circuit 11 are electrically connected (refer to...). Figure 5 When the indoor unit 500 loses power, the main control chip 13 sends a second control command to the fan unit 400. The fan drive unit 17 receives the second control command from the main control chip 13 and drives the fan 16 to stop momentarily. At this time, the capacitor 5 recovers and stores the electrical energy generated by the rotational inertia of the fan unit 400, and continues to provide power to the voltage transmission circuit 300.

[0104] As capacitor 5 continues to discharge, the voltage outputs a +17V voltage via switching transformer 6 and second rectifier circuit 72. The second rectifier circuit 72 is electrically connected to the first terminal of the first resistor 9, which serves as a current limiter.

[0105] Simultaneously, a Zener diode 10 with a breakdown voltage of +12V is connected to the second terminal of the first resistor 9 to stabilize the voltage input to the switching circuit 11 at +12V. The +12V voltage is then input through the second input terminal IN2 of the switching circuit 11, and then provides voltage to the electronic expansion valve 15 through the output terminal OUT11 of the switching circuit 11. The +12V voltage is also input through the input terminal IN12 of the voltage conversion circuit 12, and then output through the output terminal OUT12 of the voltage conversion circuit 12, providing a stable voltage to the main control chip 13.

[0106] The main control chip 13 sends a third control command to the driver chip 14, and the driver chip 14 controls the electronic expansion valve 15 to close.

[0107] The following is Figure 7 Using the structural diagram of the indoor unit shown as an example, the operation process of the indoor unit is introduced.

[0108] like Figure 8 and Figure 10 As shown, where, Figure 8 This is a flowchart of a power outage process for a multi-split air conditioner. The following describes the control flow of the main control chip in a multi-split air conditioner.

[0109] S101, Main control chip sets reference voltage value V R The main control chip sets the threshold V. T .

[0110] It should be noted that the reference voltage value V R When the indoor unit is being powered normally, the voltage value V is collected. AD The average value over time T; threshold V T When the indoor unit is being powered normally, the voltage value V is collected. AD Twice the standard deviation over time T.

[0111] S102, the main control chip 13 collects the voltage V from the third resistor 20. AD .

[0112] S103, Calculate the acquired voltage value V AD With reference voltage value V R The deviation between them, i.e., ΔV = V AD -V R .

[0113] S104. Determine whether the absolute value of the deviation exceeds the threshold V. T That is, whether |△V|>V T .

[0114] S105. If the absolute value of the deviation exceeds the threshold V T That is, |△V|>V T At this time, the indoor unit loses power.

[0115] S106, the main control chip 13 issues the first control command: the second input terminal IN2 of the switching circuit 11 is connected to the output terminal OUT11.

[0116] S107, the main control chip 13 issues the second control command: instantaneously stop the fan 16.

[0117] It should be noted that the main control chip 13 issues a second control command: the speed loop response speed of the fan 16 is adjusted from 20ms to 1ms, and the fan 16 is quickly stopped.

[0118] S108, the main control chip 13 issues a third control command: close the electronic expansion valve.

[0119] like Figure 9 and Figure 10 As shown, where, Figure 9 This is a flowchart of a multi-split air conditioner operating without power interruption. The following describes the control flow of the main control chip in a multi-split air conditioner.

[0120] S101, Main control chip 13 sets the reference voltage value V R The main control chip 13 sets the threshold V. T .

[0121] It should be noted that the reference voltage value V R When the indoor unit is being powered normally, the voltage value V is collected. AD The average value over time T; threshold V T When the indoor unit is being powered normally, the voltage value V is collected. AD Twice the standard deviation over time T.

[0122] S102, the main control chip 13 collects the voltage V from the third resistor 20. AD .

[0123] S103, Calculate the acquired voltage value V AD With reference voltage value V R The deviation between them, i.e., ΔV = V AD -V R .

[0124] S104. Determine whether the absolute value of the deviation exceeds the threshold V. T That is, whether |△V|>V T .

[0125] S201. If the absolute value of the deviation does not exceed the threshold V T That is, it satisfies |△V|≤V T At this time, the indoor unit 500 was still powered on.

[0126] S202, the main control chip 13 issues a control command: the first input terminal IN1 of the switch circuit 11 is connected to the output terminal OUT11.

[0127] S203. Meanwhile, fan 16 is operating normally.

[0128] S204 and electronic expansion valve 15 are operating stably.

[0129] The following describes a power-off shut-off control method for the electronic expansion valve in a multi-split air conditioner according to an embodiment of the present invention.

[0130] When power supply circuit 100 stops supplying power:

[0131] The main control chip 13 sends a second control command to the fan unit 400; the fan unit 400 stops momentarily according to the second control command; the energy storage circuit 200 recovers and stores the electrical energy generated by the fan unit 400 during the momentary stop; the voltage transmission circuit 300 generates the operating voltage required by the main control chip 13 and the electronic expansion valve 15 based on the electrical energy provided by the energy storage circuit 200, and transmits the operating voltage to the main control chip 13 and the electronic expansion valve 15; the main control chip 13 sends a third control command to the drive chip 14; the drive chip 14 controls the electronic expansion valve 15 to close according to the third control command.

[0132] In the event that the power supply circuit stops supplying power, the control method also includes:

[0133] The main control chip 13 sends a first control command to the switching circuit 11; according to the first control command, the switching circuit 11 electrically connects the second input terminal IN2 and the output terminal OUT11.

[0134] The voltage transmission circuit 300 generates the operating voltage required by the main control chip 13 and the electronic expansion valve 15 based on the electrical energy provided by the energy storage circuit 200, and transmits the operating voltage to the main control chip 13 and the electronic expansion valve 15. This includes: the voltage transmission circuit 300 generates the operating voltage required by the main control chip 13 and the electronic expansion valve 15 based on the electrical energy provided by the energy storage circuit 200, through the switching transformer 6, the second rectifier circuit 72, the path between the second input terminal IN2 and the output terminal OUT11 of the switching circuit 11, and the voltage conversion circuit 12, and transmits the operating voltage to the main control chip 13 and the electronic expansion valve 15.

[0135] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multi-type air conditioner comprising an indoor unit, characterized by, The indoor unit comprises a power supply circuit, an energy storage circuit, a voltage transmission circuit, a driving chip, a master control chip, a fan unit and an electronic expansion valve; the energy storage circuit comprises a capacitor; the power supply circuit is electrically connected with a first end of the energy storage circuit, the first end of the energy storage circuit is also electrically connected with the fan unit and the voltage transmission circuit, and a second end of the energy storage circuit is grounded; the voltage transmission circuit is also electrically connected with the master control chip and the electronic expansion valve; the master control chip is also electrically connected with the fan unit and the driving chip; the driving chip is also electrically connected with the electronic expansion valve; the voltage transmission circuit comprises a switching transformer, a rectifier circuit, a switching circuit and a voltage conversion circuit; the master control chip comprises a power supply end; an input end of the switching transformer is electrically connected with the energy storage circuit, an output end of the switching transformer is electrically connected with the rectifier circuit, the rectifier circuit is electrically connected with the switching circuit, the switching circuit is electrically connected with the voltage conversion circuit, and the voltage conversion circuit is electrically connected with the power supply end of the master control chip; the voltage transmission circuit further comprises a second resistor and a third resistor; the master control chip further comprises a voltage acquisition end; a first end of the second resistor is electrically connected with an output end of the switching circuit, a second end of the second resistor is electrically connected with a first end of the third resistor, and the second end of the second resistor is also electrically connected with the voltage acquisition end of the master control chip; a second end of the third resistor is grounded; the fan unit comprises a fan and a fan driving unit; the master control chip further comprises a second control end; a first end of the fan is electrically connected with the first end of the energy storage circuit, a second end of the fan is electrically connected with a first end of the fan driving unit, and a second end of the fan driving unit is electrically connected with the second control end of the master control chip; the master control chip is configured to, when the power supply circuit stops supplying power, issue a second control instruction to the fan driving unit based on the pre-stored electric energy of the energy storage circuit, so that the fan driving unit controls the fan to be instantaneously stopped; the energy storage circuit is configured to recover and store the electric energy generated by the rotational inertia during the process of the fan being instantaneously stopped, and provide electric energy for the voltage transmission circuit; the voltage transmission circuit can generate the working voltage required by the master control chip and the electronic expansion valve based on the electric energy provided by the energy storage circuit, and transmit the working voltage to the master control chip and the electronic expansion valve; the master control chip is configured to send a third control instruction to the driving chip based on the electric energy generated by the rotational inertia during the process of the fan being instantaneously stopped; the driving chip is configured to control the electronic expansion valve to be closed based on the electric energy generated by the rotational inertia during the process of the fan being instantaneously stopped according to the third control instruction. The master control chip is further configured to determine that the indoor unit is powered off if an absolute value of a difference between the collected voltage value and a reference voltage value obtained by the voltage collection end is greater than a threshold value, and the power supply circuit stops power supply; wherein the reference voltage value is an average value of the collected voltage value within a preset time period when the indoor unit is powered on and operated; and the threshold value is twice a standard deviation of the collected voltage value within the preset time period when the indoor unit is powered on and operated.

2. The multi-type air conditioner according to claim 1, characterized by A first end of the capacitor is electrically connected with the power supply circuit, the voltage transmission circuit and the fan unit, and a second end of the capacitor is grounded.

3. The multi-type air conditioner according to claim 1, wherein The switch transformer comprises a first input end, a second input end, a first output end and a second output end, the rectifier circuit comprises a first rectifier circuit and a second rectifier circuit; the switch circuit comprises a first input end, a second input end, an output end and a control end; the voltage conversion circuit comprises an input end and an output end; The master control chip further comprises a first control end; The first input end and the second input end of the switch transformer are electrically connected with the first end and the second end of the energy storage circuit respectively; the first output end of the switch transformer is electrically connected with the first rectifier circuit, and the second output end of the switch transformer is electrically connected with the second rectifier circuit; The first input end of the switch circuit is electrically connected with the first rectifier circuit, and the second input end of the switch circuit is electrically connected with the second rectifier circuit; the control end of the switch circuit is electrically connected with the first control end of the master control chip, the output end of the switch circuit is electrically connected with the input end of the voltage conversion circuit and the power supply end of the electronic expansion valve; and the output end of the voltage conversion circuit is electrically connected with the power supply end of the master control chip.

4. The multi-type air conditioner according to claim 3, characterized by The voltage transmission circuit further comprises a first resistor and a voltage stabilizing diode; The first end of the first resistor is electrically connected with the second rectifier circuit, and the second end of the first resistor is electrically connected with the second input end of the switch circuit; The positive electrode of the voltage stabilizing diode is grounded, and the negative electrode of the voltage stabilizing diode is electrically connected with the second end of the first resistor.

5. The multi-type air conditioner according to claim 4, wherein The master control chip is further configured to determine that the indoor unit is not powered off if an absolute value of a difference between the collected voltage value and the reference voltage value obtained by the voltage collection end is less than or equal to the threshold value.

6. The multi-connected air conditioner according to any one of claims 1 to 2, characterized by The drive chip comprises a plurality of input ends, a plurality of output ends and a grounding end; The master control chip further comprises a plurality of output ends; The plurality of input ends of the drive chip are connected with the plurality of output ends of the master control chip in one-to-one correspondence, the plurality of output ends of the drive chip are electrically connected with the plurality of input ends of the electronic expansion valve in one-to-one correspondence, and the grounding end of the drive chip is grounded.

7. A control method characterized by, The application is applied to power-off closing of the electronic expansion valve in the multi-connected air conditioner of any one of claims 1-6. The master control chip judges that the indoor unit is powered off when the absolute value of the difference between the acquisition voltage value obtained at the voltage acquisition end and the reference voltage value is greater than a threshold value, and the power supply circuit stops power supply; wherein the reference voltage value is the average value of the acquisition voltage value during the preset time period when the indoor unit is powered on; the threshold value is twice the standard deviation of the acquisition voltage value during the preset time period when the indoor unit is powered on; The master control chip sends a second control instruction to the fan driving unit based on the pre-stored energy of the energy storage circuit, so that the fan driving unit controls the fan to stop instantaneously; The energy storage circuit recovers and stores the energy generated by the fan unit during the instant stop process; The voltage transmission circuit generates the working voltage required by the master control chip and the electronic expansion valve based on the energy provided by the energy storage circuit, and transmits the working voltage to the master control chip and the electronic expansion valve; The master control chip sends a third control instruction to the driving chip based on the energy generated by the rotational inertia during the fan instant stop process; The driving chip controls the electronic expansion valve to close based on the energy generated by the rotational inertia during the fan instant stop process according to the third control instruction.

8. The control method according to claim 7, characterized by, The voltage transmission circuit includes a switching transformer, a rectifier circuit, a switching circuit and a voltage conversion circuit; the rectifier circuit includes a first rectifier circuit and a second rectifier circuit; the switching circuit includes a first input end, a second input end, an output end and a control end; In the case that the power supply circuit stops power supply, the control method further comprises: The master control chip sends a first control instruction to the switching circuit; The switching circuit electrically connects the second input end and the output end of the switching circuit according to the first control instruction; The voltage transmission circuit generates the working voltage required by the master control chip and the electronic expansion valve based on the energy provided by the energy storage circuit, and transmits the working voltage to the master control chip and the electronic expansion valve, comprising: The voltage transmission circuit generates the working voltage required by the master control chip and the electronic expansion valve based on the energy provided by the energy storage circuit, and transmits the working voltage to the master control chip and the electronic expansion valve via the switching transformer, the second rectifier circuit, the second input end and the output end of the switching circuit, and the voltage conversion circuit.

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