Control method, system and related device for compressor voltage sag

Abstract

The application discloses a compressor voltage drop control method, system and related equipment. The method comprises collecting the mains voltage according to a preset collection period, and calculating the effective voltage of the mains according to the mains voltage; calculating the amplitude voltage of the mains based on the effective voltage to obtain the amplitude voltage; calculating the highest running speed of the compressor based on the amplitude voltage to obtain the highest running speed of the compressor; calculating the speed adjustment amount required by the compressor based on the highest running speed and a preset speed adjustment function to obtain the speed adjustment amount; and adjusting the set speed of the compressor according to the speed adjustment amount. The method reduces the current by adjusting the set speed of the compressor, avoids the sudden increase of the current of the compressor when the mains voltage drops, and solves the problems of overcurrent shutdown and loss of excitation of the compressor.

Description

Technical Field

[0001] This invention relates to the field of compressor controller technology, and in particular to a method, system and related equipment for controlling compressor voltage drop. Background Technology

[0002] In modern variable frequency compressors with electrolytic-free control technology, the bus is a small film capacitor (3.5uF), which is only a fraction of the size of a traditional electrolytic capacitor. The energy stored is limited, and most of the energy required for compressor operation must be obtained from the mains power input. However, mains power has stability issues, such as voltage drops (voltage drops to 40% of rated voltage) and short-term power outages, which can severely affect the reliable operation of the variable frequency compressor.

[0003] When a compressor is operating under heavy load or at high speed, a sudden voltage drop can cause the compressor to shut down due to overcurrent, severely impacting the customer's experience. On the other hand, the deep magnetic field weakening caused by the voltage drop may lead to compressor demagnetization, seriously affecting the reliable operation of the compressor. Therefore, how to maintain reliable operation of the compressor when the voltage drops is an urgent problem to be solved. Summary of the Invention

[0004] This invention provides a method, system, and related equipment for controlling compressor voltage drops, aiming to solve the problem that compressors cannot operate normally when voltage drops occur in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a method for controlling compressor voltage drop, comprising:

[0006] Collect the mains voltage according to the preset collection cycle, and calculate the effective voltage of the mains voltage based on the mains voltage;

[0007] The amplitude voltage of the mains power is calculated based on the effective voltage to obtain the amplitude voltage;

[0008] The maximum operating speed of the compressor is calculated based on the amplitude voltage to obtain the maximum operating speed of the compressor;

[0009] The required speed adjustment of the compressor is calculated based on the maximum operating speed and the preset speed adjustment function to obtain the speed adjustment amount;

[0010] Adjust the compressor's set speed according to the stated speed adjustment amount.

[0011] Secondly, embodiments of the present invention provide a control system for compressor voltage drop, comprising:

[0012] The effective voltage calculation module is used to collect the mains voltage according to a preset collection period and calculate the effective voltage of the mains voltage based on the mains voltage.

[0013] An amplitude voltage calculation module is used to calculate the amplitude voltage of the mains power based on the effective voltage to obtain the amplitude voltage.

[0014] The speed calculation module is used to calculate the maximum operating speed of the compressor based on the amplitude voltage, so as to obtain the maximum operating speed of the compressor;

[0015] The speed adjustment module is used to calculate the required speed adjustment of the compressor based on the maximum operating speed and a preset speed adjustment function, and obtain the speed adjustment amount.

[0016] The control module is used to adjust the set speed of the compressor according to the speed adjustment amount.

[0017] Thirdly, embodiments of the present invention also provide a compressor device, including a speed control loop and a compressor, wherein the control loop is provided with a compressor voltage drop control system as described in the second aspect above;

[0018] The speed control loop adjusts the compressor's set speed according to the speed adjustment amount.

[0019] Fourthly, embodiments of the present invention also provide a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the compressor voltage drop control method described in the first aspect above.

[0020] Fifthly, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the compressor voltage drop control method described in the first aspect.

[0021] This invention provides a method, system, and related equipment for controlling compressor voltage drops. The method includes: acquiring mains voltage at a preset acquisition cycle and calculating the effective voltage of the mains voltage; calculating the amplitude voltage of the mains voltage based on the effective voltage; calculating the maximum operating speed of the compressor based on the amplitude voltage; calculating the required speed adjustment amount of the compressor based on the maximum operating speed and a preset speed adjustment function; and adjusting the compressor's set speed according to the speed adjustment amount. This method calculates the amplitude voltage of the mains voltage during compressor operation, calculates the maximum operating speed of the compressor based on the amplitude voltage, and when the set speed exceeds the maximum operating speed, calculates the speed adjustment amount based on the maximum operating speed and the speed adjustment function, and corrects the compressor's set speed based on the speed adjustment amount. By adjusting the compressor's set speed, the current is reduced, preventing a sudden increase in current when the mains voltage drops, which could lead to compressor overcurrent shutdown and demagnetization. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic flowchart of the compressor voltage drop control method according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of a speed controller that uses the compressor voltage drop control method of the present invention;

[0025] Figure 3 This is a schematic block diagram of the compressor voltage drop control system according to an embodiment of the present invention;

[0026] Figure 4 Test graphs of voltage and current during compressor operation without using the compressor voltage drop control method of the present invention;

[0027] Figure 5 This is a test diagram of the voltage and current of a compressor during operation using the compressor voltage drop control method of the present invention. Detailed Implementation

[0028] 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, not all, of the embodiments of the present invention. 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.

[0029] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0030] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0032] Reference Figure 1 , Figure 1 This is a flowchart illustrating an embodiment of the compressor voltage drop control method of the present invention. In this embodiment, the method includes steps S110 to S150:

[0033] Step S110: Collect the mains voltage according to the preset collection cycle, and calculate the effective voltage of the mains voltage based on the mains voltage;

[0034] Step S120: Calculate the amplitude voltage of the mains power based on the effective voltage to obtain the amplitude voltage;

[0035] In this embodiment, in order to make full use of the inherent physical quantities in vector control and reduce the overhead caused by adding a new control loop, the mains voltage is collected according to a preset acquisition period, and the effective voltage of the mains is calculated based on the mains voltage. The specific formula is as follows:

[0036] U flt (n) 2 =(U ad (n)*U ad (n)-U flt (n-1) 2 )*τT s +U flt (n-1)2 ,

[0037] Among them, T s Indicates the acquisition period; U ad (n) represents the mains voltage collected in the nth sampling; U flt (n) represents the effective voltage of the mains voltage sampled in the nth time; U flt (n-1) represents the effective voltage of the mains voltage collected in the (n-1)th time; τ represents the filtering time factor, with a value between 10 and 20.

[0038] Next, the amplitude voltage U of the mains power is calculated based on the effective voltage. max (n), the specific formula is as follows:

[0039]

[0040] Step S130: Calculate the maximum operating speed of the compressor based on the amplitude voltage to obtain the maximum operating speed of the compressor;

[0041] In this embodiment, in order to determine the relationship between the amplitude voltage and the compressor's maximum operating speed, the compressor's maximum operating speed is calculated based on whether the amplitude voltage exceeds a preset peak voltage threshold. The compressor's maximum operating speed is calculated using the following formula:

[0042]

[0043] N max (n) = MAX(N) max1 (n),N min ),

[0044] Where, N max1 (n) represents the maximum compressor speed calculated based on the amplitude voltage; N min This indicates the minimum permissible operating speed of the compressor, typically 1200 rpm. Operating below this speed will increase compressor vibration; therefore, it should not be operated below this speed. N max2 This indicates the maximum permissible operating speed of the compressor, typically 4500 rpm; p represents the proportional factor, with a value between 0.8 and 1; k e The back electromotive force coefficient of the compressor is a known parameter, typically ranging from 30 to 50; N max (n) represents the compressor's maximum operating speed; MAX() represents taking the maximum value.

[0045] Step S140: Calculate the required speed adjustment of the compressor based on the maximum operating speed and the preset speed adjustment function to obtain the speed adjustment amount;

[0046] Step S150: Adjust the set speed of the compressor according to the speed adjustment amount.

[0047] In this embodiment, a PI controller is used to calculate the speed adjustment amount. When the compressor's set speed is greater than the maximum operating speed, the required speed adjustment amount is calculated based on the maximum operating speed and a preset speed adjustment function. The compressor's set speed is then adjusted according to this speed adjustment amount to reduce the compressor's current and prevent a sudden increase in current when the mains voltage drops, which could lead to compressor overcurrent shutdown and demagnetization. The required speed adjustment amount ΔN(n) is calculated using the following formula:

[0048]

[0049] Where ΔN(n) represents the speed adjustment amount, N s (n) represents the compressor's set speed, K p and K i These are the proportional and integral parameters of the linear controller, respectively.

[0050] Furthermore, to improve the timeliness and anti-interference capability of control, this application adopts a type-two system tuning strategy. p and K i The specific calculation formula is as follows:

[0051]

[0052] Among them, J s K represents the moment of inertia of the compressor. t T represents the torque coefficient of the compressor. s N represents the control period. b I represents the voltage scaling factor. b This represents the current calibration coefficient.

[0053] In one embodiment, such as Figure 2 The diagram shows a speed controller incorporating the compressor voltage drop control method of this invention. It collects the effective voltage of the mains power supply and calculates the amplitude voltage using the compressor voltage drop control method. Based on the amplitude voltage, it calculates the compressor's maximum operating speed N using the aforementioned compressor voltage drop control method. max (n); The voltage cutoff negative feedback control module is based on the maximum operating speed N. max (n) Calculate the speed adjustment amount ΔN(n) according to the above-mentioned compressor voltage drop control method; finally, combine the speed adjustment amount ΔN(n) and the compressor set speed N. s (n) and the actual speed N of the compressor r (n) Input the speed controller, and the speed controller outputs the compressor torque T. e(n).

[0054] Reference Figure 4 and Figure 5 As shown, Figure 4 The graph shows the test voltage and current of a compressor operating without using the compressor voltage drop control method of this invention. Figure 5 The diagram shows the test values ​​of voltage and current during compressor operation using the voltage drop control method of this invention. By comparison, the compressor without the voltage drop control method of this invention shows no current fluctuation during voltage drops, indicating that the compressor stops operating; while the compressor using the voltage drop control method of this invention shows a brief current fluctuation during voltage drops, followed by a return to normal fluctuation, indicating that the compressor can continue operating.

[0055] This method calculates the amplitude voltage of the mains power during compressor operation and determines the compressor's maximum operating speed based on this amplitude voltage. When the set speed exceeds the maximum operating speed, it calculates the speed adjustment amount based on the maximum operating speed and a speed adjustment function. This adjustment amount corrects the compressor's set speed, reducing current and preventing sudden current increases that could lead to compressor overcurrent shutdown and demagnetization when the mains voltage drops. Furthermore, this method is only triggered when the voltage drops; when the voltage returns to normal, the compressor's operating speed automatically returns to the original set speed. This fully utilizes the physical quantities that must be calculated in vector control, requiring only a small increase in overhead to complete the voltage drop compensation algorithm.

[0056] This invention also provides a compressor voltage drop control system, which is used to execute any embodiment of the aforementioned compressor voltage drop control method. Specifically, please refer to... Figure 3 , Figure 3 This is a schematic block diagram of the system provided in an embodiment of the present invention. The compressor voltage drop control system 100 can be configured in a server.

[0057] like Figure 3 As shown, the compressor voltage drop control system 100 includes an effective voltage calculation module 110, an amplitude voltage calculation module 120, a speed calculation module 130, a speed adjustment module 140, and a control module 150.

[0058] The effective voltage calculation module 110 is used to collect the mains voltage according to a preset collection cycle and calculate the effective voltage of the mains voltage based on the mains voltage.

[0059] The amplitude voltage calculation module 120 is used to calculate the amplitude voltage of the mains power based on the effective voltage to obtain the amplitude voltage;

[0060] The speed calculation module 130 is used to calculate the maximum operating speed of the compressor based on the amplitude voltage, so as to obtain the maximum operating speed of the compressor;

[0061] The speed adjustment module 140 is used to calculate the required speed adjustment of the compressor based on the maximum operating speed and a preset speed adjustment function, and obtain the speed adjustment amount.

[0062] The control module 150 is used to adjust the set speed of the compressor according to the speed adjustment amount.

[0063] This invention also provides a compressor device, including a speed control loop and a compressor, wherein the speed control loop is provided with a compressor voltage drop control system as described above;

[0064] This speed control loop adjusts the compressor's set speed according to the speed adjustment amount.

[0065] In this embodiment, the compressor unit consists of a speed control circuit and a compressor. The control circuit can be a microcomputer such as a single-chip microcomputer. The control circuit is equipped with a compressor voltage drop control system. The speed adjustment amount is calculated by the compressor voltage drop control system. Finally, the control circuit adjusts the set voltage of the compressor according to the speed adjustment amount, thereby avoiding the compressor from shutting down due to overcurrent when the voltage drops.

[0066] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the compressor voltage drop control method described above.

[0067] In another embodiment of the invention, a computer-readable storage medium is provided. This computer-readable storage medium may be a non-volatile computer-readable storage medium. The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to perform the compressor voltage drop control method as described above.

[0068] Those skilled in the art will readily understand that, for the sake of convenience and brevity, the specific working processes of the devices, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0069] In the embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Units with the same function may be grouped into one unit. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, or it may be an electrical, mechanical, or other form of connection.

[0070] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0071] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0072] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), magnetic disks, or optical disks.

[0073] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered 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 method for controlling voltage drop in a compressor, characterized in that, include: Collect the mains voltage according to the preset collection cycle, and calculate the effective voltage of the mains voltage based on the mains voltage; The amplitude voltage of the mains power is calculated based on the effective voltage to obtain the amplitude voltage; The maximum operating speed of the compressor is calculated based on the amplitude voltage to obtain the maximum operating speed of the compressor; The required speed adjustment of the compressor is calculated based on the maximum operating speed and the preset speed adjustment function to obtain the speed adjustment amount; Adjust the compressor's set speed according to the stated speed adjustment amount; The speed adjustment function is as follows: Where ΔN(n) represents the speed adjustment amount, N s (n) represents the compressor's set speed, K p and K i These are the proportional and integral parameters of the linear controller, respectively, N. max (n) represents the compressor's maximum operating speed.

2. The compressor voltage drop control method according to claim 1, characterized in that, The step of collecting mains voltage according to a preset collection period and calculating the effective mains voltage based on the mains voltage includes: Calculate the effective voltage of the mains power using the following formula: Among them, T s Indicates the acquisition period, U ad (n) represents the mains voltage collected in the nth sampling, U flt (n) represents the effective voltage of the mains voltage collected in the nth time, U flt (n-1) represents the effective voltage of the mains voltage collected in the (n-1)th time, and τ represents the filtering time factor.

3. The compressor voltage drop control method according to claim 2, characterized in that, The calculation of the amplitude voltage of the mains power based on the effective voltage to obtain the amplitude voltage includes: The amplitude voltage is calculated using the following formula: Among them, U max (n) represents the amplitude voltage.

4. The compressor voltage drop control method according to claim 3, characterized in that, The calculation of the compressor's maximum operating speed based on the amplitude voltage, to obtain the compressor's maximum operating speed, includes: The maximum operating speed is calculated using the following formula: N max (n)=MAX(N max1 (n),N min ) Where, N max1 (n) represents the maximum compressor speed calculated based on the amplitude voltage, N min Indicates the minimum permissible operating speed of the compressor, N max2 This indicates the maximum permissible operating speed of the compressor, p represents the proportional factor, and k... e This represents the back electromotive force coefficient of the compressor, and MAX() indicates taking the maximum value.

5. The compressor voltage drop control method according to claim 1, characterized in that, The K p and K i Calculate using the following formula: Among them, J s K represents the moment of inertia of the compressor. t T represents the torque coefficient of the compressor. s N represents the data acquisition period. b I represents the voltage scaling factor. b This represents the current calibration coefficient.

6. A control system for compressor voltage drop, characterized in that, include: The effective voltage calculation module is used to collect the mains voltage according to a preset collection period and calculate the effective voltage of the mains voltage based on the mains voltage. An amplitude voltage calculation module is used to calculate the amplitude voltage of the mains power based on the effective voltage to obtain the amplitude voltage. The speed calculation module is used to calculate the maximum operating speed of the compressor based on the amplitude voltage, so as to obtain the maximum operating speed of the compressor; The speed adjustment module is used to calculate the required speed adjustment of the compressor based on the maximum operating speed and a preset speed adjustment function, and obtain the speed adjustment amount. The control module is used to adjust the set speed of the compressor according to the speed adjustment amount; The speed adjustment function is as follows: Where ΔN(n) represents the speed adjustment amount, N s (n) represents the compressor's set speed, K p and K i These are the proportional and integral parameters of the linear controller, respectively, N. max (n) represents the compressor's maximum operating speed.

7. A compressor device, characterized in that, It includes a speed control loop and a compressor, wherein the speed control loop is provided with a compressor voltage drop control system as described in claim 6; The speed control loop adjusts the compressor's set speed according to the speed adjustment amount.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the compressor voltage drop control method as described in any one of claims 1 to 5.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to perform the compressor voltage drop control method as described in any one of claims 1 to 5.

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