A method and system for regulating input current of multi-connected air conditioner

Abstract

A method and system for regulating the input current of a multi-split air conditioner includes the following steps: when the multi-split air conditioner receives a control instruction, parsing the target opening and closing degrees of each capillary in the control instruction; calculating the total target power of each valve controlled to the target opening and closing degrees; obtaining the input power of each valve as a first power, and calculating all first powers to obtain the total actual power; determining whether the difference between the total actual power and the total target power is greater than a difference threshold; if the difference is greater than the difference threshold, obtaining the bus voltage, and regulating the input current based on the bus voltage. The present invention provides precise temperature control and stable system operation, allowing users to use the multi-split air conditioner more conveniently and comfortably without frequent manual adjustments, greatly improving user experience and satisfaction.

Description

Technical Field

[0001] The present invention relates to the technical field of air-conditioning control, and in particular to a method and system for regulating input current of a multi-connected air-conditioner. Background Art

[0002] The operating principle of a multi-split air conditioner is that a single outdoor unit delivers refrigerant liquid to several indoor units via pipes. In a multi-split air conditioning system, the outdoor unit adjusts the refrigerant circulation volume and the refrigerant flow rate entering each indoor heat exchanger to achieve real-time adjustments based on the indoor cooling and heating load requirements, thereby achieving precise temperature control. However, since a single outdoor unit typically controls multiple indoor units, each with different temperature requirements, this requires precise, differentiated control of each capillary valve connecting the indoor units. To achieve this, the valves of each indoor unit must be independently controlled to ensure that the refrigerant flow rate of each indoor unit can be adjusted according to its specific temperature requirements.

[0003] However, in actual operation, the phase difference between the voltage and input current controlled by the compressor may make it impossible to meet the requirements of fine-grained control when setting the input current initially. Specifically, improper adjustment of the voltage or current of the outdoor unit can lead to uneven cooling performance across the entire system, affecting temperature control and energy efficiency. Therefore, how to accurately control the current and voltage of each capillary valve to achieve fine-grained adjustment of the temperature requirements of each indoor unit has become a key issue in multi-split air conditioning systems. Summary of the Invention

[0004] In view of the above-mentioned defects, the purpose of the present invention is to propose a method and system for adjusting the input current of a multi-split air conditioner to solve the problem that the temperature operation of the air conditioner cannot be accurately controlled in the multi-split air conditioner.

[0005] To achieve this purpose, the present invention adopts the following technical solution: a method for adjusting the input current of a multi-connected air conditioner, comprising the following steps:

[0006] Step S1: When the multi-split air conditioner receives a control instruction, it analyzes the target opening and closing degrees of each capillary tube in the control instruction;

[0007] Step S2: Counting the total target power of each valve controlled to the target opening and closing degree;

[0008] Step S3: obtaining the input power of each valve as the first power, and counting all the first powers to obtain the total actual power;

[0009] Step S4: Determine whether the difference between the total actual power and the total target power is greater than a difference threshold; if the difference is greater than the difference threshold, obtain the bus voltage and adjust the input current based on the bus voltage.

[0010] Preferably, the specific steps in step S2 are as follows:

[0011] Step S21: obtaining an adjusted valve opening degree based on a difference between an original valve opening degree and a target valve opening degree;

[0012] Step S22: Obtaining a valve type coefficient, and obtaining the motor torque required for this opening / closing degree adjustment through the valve type coefficient and the adjustment opening / closing degree;

[0013] Step S23: Obtain the speed specification of the valve motor, and obtain the target power of the valve according to the motor torque and speed specification;

[0014] Step S24: Counting the target powers of all valves that need to be adjusted to obtain the total target power.

[0015] Preferably, the calculation formula of the motor torque is as follows:

[0016] T i =K*p*ΔD i *f;

[0017] Where K is the valve type coefficient, p is the pressure when the valve is at the target opening and closing degree, ΔD i is to adjust the opening and closing degree, f is the friction coefficient;

[0018] The target power is obtained by the following formula:

[0019]

[0020] Where T i is the motor torque of the i-th valve, n is the speed specification, α is the age coefficient, and β is the constant coefficient for converting power, torque, and speed units.

[0021] Preferably, the bus voltage includes an independent bus voltage and a shared bus voltage;

[0022] When the bus voltage is an independent bus voltage, a weighted average value of the independent bus voltage is obtained to adjust the input current;

[0023] When the bus voltage is a shared bus voltage, the shared bus voltage is used to regulate the input current.

[0024] Preferably, the formula for adjusting the input current based on the bus voltage in step S4 is as follows:

[0025]

[0026] Among them, P i is the target power, V d is the bus voltage and k is the regulation coefficient.

[0027] Preferably, the method further comprises the steps of:

[0028] Step A1: Return the valve to its original position and re-execute the valve control instruction based on the adjusted current;

[0029] Step A2: reacquiring the input power of the valve as the second power;

[0030] Step A3: Count all the second powers to obtain the corrected total actual power;

[0031] Step A4: obtaining a difference between the corrected total actual power and the total target power as a first difference;

[0032] Step A5: If the first difference is greater than the difference threshold, the adjustment coefficient is corrected through the PI controller and the first difference.

[0033] Preferably, the formula for correcting the adjustment coefficient in step A5 is as follows:

[0034]

[0035] Where θ is a constant coefficient, K p and K i is the gain coefficient of the PI controller, e is the current first difference, is the average of the historical first differences, and t is the number of corrections.

[0036] A multi-connected air conditioner input current regulating system, using the multi-connected air conditioner input current regulating method, comprising an instruction parsing module, a first statistical module, a second statistical module and a calculation and regulation module;

[0037] The instruction parsing module is used to parse the target opening and closing degrees of each capillary tube in the control instruction when the multi-connected air conditioner receives the control instruction;

[0038] The first statistical module is used to count the total target power of each valve controlled to the target opening and closing degree;

[0039] The second statistical module is used to obtain the input power of each valve as the first power, and to count all the first powers to obtain the total actual power;

[0040] The calculation and adjustment module is used to determine whether the difference between the total actual power and the total target power is greater than a difference threshold. If the difference is greater than the difference threshold, the bus voltage is obtained and the input current is adjusted based on the bus voltage.

[0041] One of the above technical solutions has the following advantages or beneficial effects: The precise temperature control and stable system operation of the present invention enable users to use multi-split air conditioners more conveniently and comfortably without frequent manual adjustment, greatly improving the user experience and satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow chart of an embodiment of the method of the present invention.

[0043] Figure 2 It is a structural diagram of an embodiment of the system of the present invention. DETAILED DESCRIPTION

[0044] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention.

[0045] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically specified.

[0046] Furthermore, 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "plurality" means two or more. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0047] like Figures 1-2 As shown, a method for adjusting the input current of a multi-split air conditioner includes the following steps:

[0048] Step S1: When the multi-split air conditioner receives a control instruction, it analyzes the target opening and closing degrees of each capillary tube in the control instruction;

[0049] Step S2: Counting the total target power of each valve controlled to the target opening and closing degree;

[0050] Step S3: obtaining the input power of each valve as the first power, and counting all the first powers to obtain the total actual power;

[0051] Step S4: Determine whether the difference between the total actual power and the total target power is greater than a difference threshold; if the difference is greater than the difference threshold, obtain the bus voltage and adjust the input current based on the bus voltage.

[0052] In actual multi-split air conditioner applications, the environments in which different indoor units operate are complex and diverse, with factors such as room size, orientation, insulation performance, occupant activity, and ambient temperature significantly impacting the cooling and heating performance. Therefore, the initially configured input current parameters for the multi-split air conditioner may not accurately control the opening and closing of each capillary tube to the target desired level. This can lead to inaccurate temperature control for each indoor unit, causing indoor temperature deviations and impacting user comfort.

[0053] In the proposed solution, when a multi-split air conditioner receives a control command, the system immediately conducts an in-depth analysis of the command. If the command includes a temperature control command, the system accurately determines the target opening / closing degree for each indoor unit's capillary tube by searching the detailed parameter table for the multi-split air conditioner product based on a pre-established linear relationship between the temperature control command and the target opening / closing degree of the indoor unit's capillary tube. This precise matching based on product parameters ensures that the target opening / closing degree setting meets the actual performance characteristics of the multi-split air conditioner, laying the foundation for subsequent precise control.

[0054] Taking into account that in actual use of multi-split air conditioners, there may be situations where multiple indoor units issue control commands at the same time, the system will comprehensively count the total target power required for all valves involved in this control command when adjusting to the target opening and closing degrees.

[0055] After a multi-split air conditioner receives a control command and begins executing the corresponding capillary valve control operation, the system uses high-precision sensors installed on each valve to obtain the actual input power in real time. This actual input power is then aggregated and statistically analyzed to obtain the total actual power. By accurately determining the difference between the total actual power and the total target power, the system can promptly detect any errors that may occur during the control process.

[0056] If the difference between the total actual power and the total target power is greater than the preset difference threshold, it means that the error in this adjustment process exceeds the reasonable control floating range, and there may be unreasonable parameter settings or other potential problems. At this time, the system will quickly obtain the bus voltage and, based on the difference between the total actual power and the total target power, accurately adjust the input current. Through this current regulation method based on real-time data and intelligent algorithms, the system can quickly respond and adjust the operating status of the multi-split air conditioner, so that the capillary opening and closing degree of each indoor unit is closer to the target opening and closing degree, thereby achieving precise control of the temperature of the multi-split air conditioner.

[0057] The precise temperature control and stable system operation of the present invention enable users to use multi-split air conditioners more conveniently and comfortably without frequent manual adjustments, greatly improving the user experience and satisfaction.

[0058] Preferably, the specific steps in step S2 are as follows:

[0059] Step S21: obtaining an adjusted valve opening degree based on a difference between an original valve opening degree and a target valve opening degree;

[0060] Step S22: Obtaining a valve type coefficient, and obtaining the motor torque required for this opening / closing degree adjustment through the valve type coefficient and the adjustment opening / closing degree;

[0061] Step S23: Obtain the speed specification of the valve motor, and obtain the target power of the valve according to the motor torque and speed specification;

[0062] Step S24: Counting the target powers of all valves that need to be adjusted to obtain the total target power.

[0063] Preferably, the calculation formula of the motor torque is as follows:

[0064] T i =K*p*ΔD i *f;

[0065] Where K is the valve type coefficient, p is the pressure when the valve is at the target opening and closing degree, ΔD i is to adjust the opening and closing degree, f is the friction coefficient;

[0066] The target power is obtained by the following formula:

[0067]

[0068] Where T i is the motor torque of the i-th valve, n is the speed specification, α is the age coefficient, and β is the constant coefficient for converting power, torque, and speed units.

[0069] Since the input current can no longer effectively control the valve, the voltage and current method can no longer be used to obtain the target power. In the present invention, by obtaining the type of valve, and then using the valve type coefficient and adjusting the opening and closing degree, the torque required by the motor is first obtained to adjust the valve to the target opening and closing degree. Different valves have different valve type coefficient values, for example: gate valve K = 0.15-0.3, ball valve K = 0.2-0.35, butterfly valve K = 0.1-0.2. The corresponding valve type coefficient can be obtained according to the specific type of each valve and the experiment. After knowing its torque, the corresponding target power can be obtained through the speed of the motor. When calculating the target power, the influence of the service life needs to be considered. For this reason, in the present invention, the age coefficient will be added to the calculation of the target power, and the target power will be adjusted by the age coefficient so that the target power conforms to the actual calculation result.

[0070] Preferably, the bus voltage includes an independent bus voltage and a shared bus voltage;

[0071] When the bus voltage is an independent bus voltage, a weighted average value of the independent bus voltage is obtained to adjust the input current;

[0072] When the bus voltage is a shared bus voltage, the shared bus voltage is used to regulate the input current.

[0073] In the present invention, the input current is regulated by the inverter module. When the inverter is used, there is a situation where all inverter modules share the same set of DC bus capacitors. At this time, the DC voltage of each inverter installed on the indoor unit comes from the same bus, so the voltage value is a global unified value. At this time, it is only necessary to obtain the voltage on any circuit.

[0074] However, each inverter module has its own independent DC bus capacitor, and the DC voltages of each module are isolated from each other, so the voltage values ​​may vary significantly depending on the load. However, since the input voltage is fixed, the bus voltages do not vary much. To facilitate regulation and control, when the bus voltages are independent, the weighted average of the independent bus voltages is used to adjust the input current. If the independent bus voltage average is used directly, the power contribution difference will be ignored, resulting in errors. By weighting each independent bus voltage and then dividing it by the number of independent buses, a weighted average of the independent bus voltages is obtained. Using this weighted average of the independent bus voltages to adjust the input current makes the calculated results more accurate to actual operating conditions.

[0075] Preferably, the formula for adjusting the input current based on the bus voltage in step S4 is as follows:

[0076]

[0077] Among them, P i is the target power, V d is the bus voltage and k is the regulation coefficient.

[0078] Preferably, the method further comprises the steps of:

[0079] Step A1: Return the valve to its original position and re-execute the valve control instruction based on the adjusted current;

[0080] Step A2: reacquiring the input power of the valve as the second power;

[0081] Step A3: Count all the second powers to obtain the corrected total actual power;

[0082] Step A4: obtaining a difference between the corrected total actual power and the total target power as a first difference;

[0083] Step A5: If the first difference is greater than the difference threshold, the adjustment coefficient is corrected through the PI controller and the first difference.

[0084] Preferably, the formula for correcting the adjustment coefficient in step A5 is as follows:

[0085]

[0086] Where θ is a constant coefficient, K p and K i is the gain coefficient of the PI controller, e is the current first difference, is the average of the historical first differences, and t is the number of corrections.

[0087] In the present invention, the input current is primarily regulated by the adjustment coefficient k. The initial value of the adjustment coefficient k is obtained through simulation experiments. However, in actual operation, various influences may occur, resulting in the adjusted input current still not being able to meet the control requirements. For this reason, the adjustment coefficient is also updated and corrected in the present invention.

[0088] After the input current is adjusted in step S4, the input current obtained at this point is the input current required to adjust the valve from its original opening to the target opening. To determine whether the corrected parameters meet the control requirements, the valve is restored to its original opening. The valve control command is then re-executed based on the input current. The actual input power is then acquired in real time using a high-precision sensor as the second power. All second powers are then summed to obtain the corrected total actual power. The first difference between the corrected total actual power and the total target power is used to determine whether the current input current meets the control requirements. If the first difference is greater than the difference threshold, the adjustment coefficient k still cannot meet the control requirements. The first difference and historical data of the first difference are then obtained and aligned for correction. By incorporating the average of the historical first differences into the PI controller, a long-term performance assessment of the system is provided. By using this average of the historical first differences as the PI controller input feature, the PI controller can comprehensively consider past adjustment situations. This allows the PI controller to perceive the changing trend of the first difference, allowing for more flexible adjustment of the adjustment coefficient k.

[0089] A multi-connected air conditioner input current regulating system, using the multi-connected air conditioner input current regulating method, comprising an instruction parsing module, a first statistical module, a second statistical module and a calculation and regulation module;

[0090] The instruction parsing module is used to parse the target opening and closing degrees of each capillary tube in the control instruction when the multi-connected air conditioner receives the control instruction;

[0091] The first statistical module is used to count the total target power of each valve controlled to the target opening and closing degree;

[0092] The second statistical module is used to obtain the input power of each valve as the first power, and to count all the first powers to obtain the total actual power;

[0093] The calculation and adjustment module is used to determine whether the difference between the total actual power and the total target power is greater than a difference threshold. If the difference is greater than the difference threshold, the bus voltage is obtained and the input current is adjusted based on the bus voltage.

[0094] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0095] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A method for adjusting the input current of a multi-connected air conditioner, characterized in that: The steps include: Step S1: When the multi-split air conditioner receives a control instruction, it analyzes the target opening and closing degrees of each capillary tube in the control instruction; Step S2: Counting the total target power of each valve controlled to the target opening and closing degree; Step S3: obtaining the input power of each valve as the first power, and counting all the first powers to obtain the total actual power; Step S4: determining whether the difference between the total actual power and the total target power is greater than a difference threshold; if the difference is greater than the difference threshold, obtaining the bus voltage, and adjusting the input current based on the bus voltage; The specific steps in step S2 are as follows: Step S21: obtaining an adjusted valve opening degree based on a difference between an original valve opening degree and a target valve opening degree; Step S22: Obtaining a valve type coefficient, and obtaining the motor torque required for this opening / closing degree adjustment through the valve type coefficient and the adjustment opening / closing degree; Step S23: Obtain the speed specification of the valve motor, and obtain the target power of the valve according to the motor torque and speed specification; Step S24: Counting the target powers of all valves that need to be adjusted to obtain the total target power; The calculation formula of the motor torque is as follows: ； Where K is the valve type coefficient, p is the pressure when the valve is at the target opening and closing degree, is to adjust the opening and closing degree, f is the friction coefficient; The target power is obtained by the following formula: ； in is the motor torque of the i-th valve, n is the speed specification, is the age coefficient, Constant coefficient for converting power, torque and speed units.

2. The method for adjusting the input current of a multi-connected air conditioner according to claim 1, characterized in that: The bus voltage includes an independent bus voltage and a shared bus voltage; When the bus voltage is an independent bus voltage, a weighted average value of the independent bus voltage is obtained to adjust the input current; When the bus voltage is a shared bus voltage, the shared bus voltage is used to regulate the input current.

3. The method for adjusting the input current of a multi-connected air conditioner according to claim 2, characterized in that: The formula for adjusting the input current based on the bus voltage in step S4 is as follows: ； in is the target power, is the bus voltage and k is the regulation coefficient.

4. The method for adjusting the input current of a multi-connected air conditioner according to claim 3, characterized in that: Also includes the following steps: Step A1: Return the valve to its original position and re-execute the valve control instruction based on the adjusted current; Step A2: reacquiring the input power of the valve as the second power; Step A3: Count all the second powers to obtain the corrected total actual power; Step A4: obtaining a difference between the corrected total actual power and the total target power as a first difference; Step A5: If the first difference is greater than the difference threshold, the adjustment coefficient is corrected through the PI controller and the first difference.

5. The method for adjusting the input current of a multi-connected air conditioner according to claim 4, characterized in that: The formula for correcting the adjustment coefficient in step A5 is as follows: ； in is a constant coefficient, and is the gain coefficient of the PI controller, e is the current first difference, The average value of the first historical difference, The number of corrections.

6. A multi-connected air conditioner input current regulation system, characterized in that: A method for adjusting the input current of a multi-split air conditioner according to any one of claims 1 to 5, comprising an instruction parsing module, a first statistical module, a second statistical module, and a calculation and adjustment module; The instruction parsing module is used to parse the target opening and closing degrees of each capillary tube in the control instruction when the multi-connected air conditioner receives the control instruction; The first statistical module is used to count the total target power of each valve controlled to the target opening and closing degree; The second statistical module is used to obtain the input power of each valve as the first power, and to count all the first powers to obtain the total actual power; The calculation and adjustment module is used to determine whether the difference between the total actual power and the total target power is greater than a difference threshold. If the difference is greater than the difference threshold, the bus voltage is obtained and the input current is adjusted based on the bus voltage.

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