A water pump control method, device, equipment and storage medium

Abstract

The embodiment of the present invention relates to a water pump control method, device, equipment and storage medium. The method includes: determining the current demand value of the phase current according to the speed deviation between the actual motor speed and the target speed; determining the phase current limit value according to the corresponding relationship between the power and the phase current at the actual motor speed and the power limit value in the control mode in which the d-axis current is 0 in the rotating coordinate system; determining the phase current target value according to the current demand value and the phase current limit value; determining the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value. The technical solution of the embodiment of the present invention can improve the accuracy of the water pump power limit.

Description

Technical Field

[0001] The present invention relates to the technical field of water pump control, and in particular to a water pump control method, device, equipment and storage medium. Background Art

[0002] According to the design requirements of the water pump components and the power supply requirements and operating environment requirements of the system where the water pump is located, the water pump needs to operate below the rated power.

[0003] The existing water pump power limiting control method calculates the bus current by sampling the bus current or estimates the bus current based on the sampling of the phase current, and then calculates the actual operating power by collecting the bus voltage, and limits the power by closed-loop feedback control based on the deviation between the actual operating power and the target power.

[0004] However, the existing water pump power limit control method, if the bus current sampling is used, will increase the cost and there will be sampling errors. If the bus current estimation is used, the estimation will be inaccurate, resulting in deviation in power limit; in addition, feedback control will cause control lag and power overshoot; when the power does not reach the power limit point at low speed, the speed closed loop needs to be used, and when the power is close to the rated power, the power loop is used for power closed loop control. There are speed loop and power loop switching under different working conditions, the control logic is complex, and there is a risk of power control failure. Summary of the invention

[0005] The present invention provides a water pump control method, device, equipment and storage medium, aiming to improve the accuracy of water pump power limitation.

[0006] In a first aspect, an embodiment of the present invention provides a water pump control method, comprising:

[0007] Determine the current demand value of the phase current according to the speed deviation between the actual speed of the motor and the target speed;

[0008] In the control mode where the d-axis current is 0 in the rotating coordinate system, the phase current limit is determined according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value;

[0009] Determining a phase current target value according to the current demand value and the phase current limit value;

[0010] The voltage and current of the rotating coordinate system are determined according to the deviation between the phase current target value and the current actual value.

[0011] In a second aspect, an embodiment of the present invention provides a water pump control device, comprising:

[0012] A current demand value determination module is used to determine the current demand value of the phase current according to the speed deviation between the actual speed of the motor and the target speed;

[0013] The phase current limit determination module is used to determine the phase current limit value according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value in the control mode in which the d-axis current is 0 in the rotating coordinate system;

[0014] A phase current target value determination module, used to determine the phase current target value according to the current demand value and the phase current limit value;

[0015] The voltage and current determination module is used to determine the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value.

[0016] In a third aspect, an embodiment of the present invention provides an electronic device, including:

[0017] one or more processors;

[0018] A memory for storing one or more programs;

[0019] When the one or more programs are executed by the one or more processors, the one or more processors implement the water pump control method provided by any embodiment of the present invention.

[0020] In a fourth aspect, an embodiment of the present invention provides a storage medium comprising computer executable instructions, which, when executed by a computer processor, are used to execute a water pump control method as provided in any embodiment of the present invention.

[0021] A water pump control method, device, equipment and storage medium provided by the embodiments of the present invention determine the phase current limit through the correspondence between the power and the phase current at a certain speed of the motor combined with the power limit value, and determine the phase current target value according to the current demand value and the phase current limit value, and then determine the voltage and current of the rotating coordinate system, thereby solving the problem of complex water pump power control and achieving high control accuracy, simple control and fast response speed of water pump power limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart of a water pump control method provided in Embodiment 1 of the present invention;

[0023] Figure 2 A schematic diagram of the structure of a water pump control device provided in Embodiment 2 of the present invention;

[0024] Figure 3 A schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present invention;

[0025] Figure 4 is a schematic diagram of a motor driver in an embodiment of the present invention;

[0026] Figure 5 is a schematic diagram of parameter estimation in an embodiment of the present invention;

[0027] Figure 6 A schematic diagram of the deviation between the calculated power and the actual power in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0029] Embodiment 1

[0030] Figure 1 This is a flow chart of a water pump control method provided in Embodiment 1 of the present invention. This embodiment is applicable to the case where a water pump driven by a permanent magnet synchronous motor controls power. The method can be executed by a water pump control device, which can be implemented by hardware and / or software and can generally be integrated in an electronic device, such as a computer device. The method specifically includes:

[0031] Step 110: Determine the current demand value of the phase current according to the speed deviation between the actual speed of the motor and the target speed.

[0032] Among them, permanent magnet synchronous motors are usually controlled in water pump control applications with the d-axis current being 0 in the rotating coordinate system (I d =0). Its control structure adopts double closed-loop control. The outer loop calculates the current demand value I of the phase current according to the speed deviation between the actual motor speed and the target speed. s (When I d =0, I s =I q ) as the input of the inner current loop.

[0033] Step 120 : Under the control mode in which the d-axis current is 0 in the rotating coordinate system, the phase current limit value is determined according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value.

[0034] Among them, since the water pump needs to operate at rated power, that is, the power of the water pump needs to be limited, therefore, after determining the current demand value, the current demand value cannot be directly used to control the motor. The phase current limit value needs to be determined, and the phase current cannot exceed the phase current limit value.

[0035] Step 130: Determine a phase current target value according to the current demand value and the phase current limit value.

[0036] The current demand value and the phase current limit value need to be compared to determine the phase current target value. The goal is to control the motor so that the phase current limit value is not exceeded.

[0037] Step 140: Determine the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value.

[0038] Wherein, the current loop outputs the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the actual value. Optionally, after determining the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value, it also includes: converting the voltage and current of the rotating coordinate system into a three-phase voltage based on the inverse Park transformation and the inverse Clark transformation and outputting it to the motor. (such as Figure 4 As shown, the dotted box is the driver part).

[0039] The technical solution of this embodiment determines the phase current limit through the correspondence between the power and the phase current at a certain speed of the motor combined with the power limit value, and determines the phase current target value according to the current demand value and the phase current limit value, and then determines the voltage and current of the rotating coordinate system, thereby solving the problem of complex power control of the water pump and achieving high control accuracy, simple control and fast response speed of the water pump power limit.

[0040] Optionally, determining the phase current target value according to the current demand value and the phase current limit value includes:

[0041] When the current demand value at the actual speed of the motor is lower than the phase current limit value, determining the current demand value as the phase current target value;

[0042] When the current demand value at the actual speed of the motor is higher than or equal to the phase current limit value, the phase current limit value is determined as the phase current target value.

[0043] Optionally, in the control mode in which the d-axis current is 0 in the rotating coordinate system, the phase current limit value is determined according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value, including:

[0044] In the control mode where the d-axis current is 0 in the rotating coordinate system, based on the power balance equation of the motor, according to the actual motor speed, internal resistance, back electromotive force coefficient and the power limit value, the q-axis current value is determined and used as the phase current limit value.

[0045] Optionally, in the control mode in which the d-axis current is 0 in the rotating coordinate system, based on the power balance equation of the motor, according to the actual motor speed, internal resistance, back electromotive force coefficient and the power limit value, the q-axis current value is determined and used as the phase current limit value, including:

[0046] When the d-axis current is 0, the power balance equation of the motor is determined; wherein, in the power balance equation, the power is related to the motor speed, internal resistance, back electromotive force coefficient and q-axis current; the power balance equation of the permanent magnet synchronous motor can be expressed as: (Where: P is power (W), R s is the internal resistance (Ω), I q is the q-axis current (A), K e is the back EMF coefficient (V / rpm), N s is the speed (rpm). According to the formula, the power of the water pump is related to the internal resistance, q-axis current, back-EMF coefficient and speed.

[0047] At the actual speed of the motor, the internal resistance and the back electromotive force coefficient are taken as constants to determine that there is a preset corresponding relationship between the power and the q-axis current;

[0048] According to the preset correspondence between power and q-axis current and the power limit value, the q-axis current value is calculated and used as the phase current limit value. The internal resistance and back-EMF coefficient are parameters of the motor itself and are constants. Therefore, if the internal resistance and back-EMF coefficient of the motor can be estimated, When the speed is constant, the q-axis current value (I q ). In the rotating coordinate system, the d-axis current is 0 (I d =0), the q-axis current and phase current of the water pump motor in the rotating coordinate system are equal, and the q-axis current value calculated according to the power limit value can be used as the phase current limit value

[0049] Optionally, the estimated internal resistance is obtained from the motor design parameters or measured motor parameters and back EMF coefficient The value of Figure 5 As shown, the internal resistance and back EMF coefficient are determined as follows:

[0050] Under different pump operating conditions, the peak value and frequency of the phase current are collected to calculate the corresponding q-axis current I q and speed N s , and record the power at the water pump input;

[0051] Under different pump operating conditions, the real-time variable q-axis current I of the driver is collected. q and speed N s , record the power P at the water pump input;

[0052] Each group of data (N s (i) I q (i)) Substitute into the power balance equation and calculate the power for each set of data: in, and is the estimated internal resistance and back EMF coefficient;

[0053] According to the least squares theory, the power of each group of data in the collected data and the square sum function of the power residual calculated by the corresponding speed and phase current are: When the function value is minimized, and It is the optimal estimated parameter of the internal resistance and back EMF coefficient that satisfies the power balance equation.

[0054] Estimated parameters and The deviation between the power calculated by open loop and the actual power when put into the power balance equation is as follows: Figure 6 As shown in the figure (orange is actual power, blue is open-loop calculated power). The calculated power and actual power match very well under different working conditions, indicating that the estimated parameters are accurate.

[0055] Embodiment 2

[0056] Figure 2 A schematic diagram of the structure of a water pump control device provided in the second embodiment of the present invention is shown in FIG. Figure 2 As shown, the water pump control device includes: a current demand value determination module 210, a phase current limit value determination module 220, a phase current target value determination module 230 and a voltage and current determination module 240, wherein:

[0057] A current demand value determination module 210, configured to determine a current demand value of a phase current according to a speed deviation between an actual motor speed and a target speed;

[0058] The phase current limit determination module 220 is used to determine the phase current limit according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value in the control mode in which the d-axis current is 0 in the rotating coordinate system;

[0059] A phase current target value determination module 230, configured to determine a phase current target value according to the current demand value and the phase current limit value;

[0060] The voltage and current determination module 240 is used to determine the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value.

[0061] Optionally, the phase current target value determination module is specifically used to:

[0062] When the current demand value at the actual speed of the motor is lower than the phase current limit value, determining the current demand value as the phase current target value;

[0063] When the current demand value at the actual speed of the motor is higher than or equal to the phase current limit value, the phase current limit value is determined as the phase current target value.

[0064] Optionally, the water pump control device further comprises:

[0065] The three-phase voltage output module is used to convert the voltage and current of the rotating coordinate system into a three-phase voltage based on inverse Park transformation and inverse Clark transformation and output it to the motor after determining the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value.

[0066] Optionally, the phase current limit determination module is specifically used to:

[0067] In the control mode where the d-axis current is 0 in the rotating coordinate system, based on the power balance equation of the motor, according to the actual motor speed, internal resistance, back electromotive force coefficient and the power limit value, the q-axis current value is determined and used as the phase current limit value.

[0068] Optionally, the phase current limit determination module is specifically used to:

[0069] When the d-axis current is 0, determine the power balance equation of the motor; wherein, in the power balance equation, the power is related to the motor speed, internal resistance, back electromotive force coefficient and q-axis current;

[0070] At the actual speed of the motor, the internal resistance and the back electromotive force coefficient are taken as constants to determine that there is a preset corresponding relationship between the power and the q-axis current;

[0071] According to the preset corresponding relationship between power and q-axis current and the power limit value, the q-axis current value is calculated and used as the phase current limit value.

[0072] Optionally, the water pump control device further comprises:

[0073] The parameter estimation module is used to determine the internal resistance and back EMF coefficient as follows:

[0074] Under different pump operating conditions, the peak value and frequency of the phase current are collected to calculate the corresponding q-axis current I q and speed N s , and record the power at the water pump input;

[0075] Under different pump operating conditions, the real-time variable q-axis current I of the driver is collected. q and speed N s , record the power P at the water pump input;

[0076] Each group of data (N s (i) I q(i)) Substitute into the power balance equation and calculate the power for each set of data: in, and is the estimated internal resistance and back EMF coefficient;

[0077] According to the least squares theory, the power of each group of data in the collected data and the square sum function of the power residual calculated by the corresponding speed and phase current are: When the function value is minimized, and It is the optimal estimated parameter of the internal resistance and back EMF coefficient that satisfies the power balance equation.

[0078] The water pump control device provided in the embodiment of the present invention can execute the water pump control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0079] Embodiment 3

[0080] Figure 3 A schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present invention is shown in FIG. Figure 3 As shown, the electronic device includes a processor 310, a memory 320, an input device 330 and an output device 340; the number of the processor 310 in the electronic device can be one or more. Figure 3 A processor 310 is taken as an example; the processor 310, the memory 320, the input device 330 and the output device 340 in the electronic device can be connected via a bus or other means. Figure 3 The example of connecting through bus is taken in the following.

[0081] The memory 320, as a computer-readable storage medium, can be used to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the water pump control method in the embodiment of the present invention (for example, the current demand value determination module 210, the phase current limit value determination module 220, the phase current target value determination module 230 and the voltage and current determination module 240 in the water pump control device). The processor 310 executes various functional applications and data processing of the electronic device by running the software programs, instructions and modules stored in the memory 320, that is, realizes the above-mentioned water pump control method.

[0082] The memory 320 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and at least one application required for a function; the data storage area may store data created according to the use of the terminal, etc. In addition, the memory 320 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 320 may further include a memory remotely arranged relative to the processor 310, and these remote memories may be connected to the electronic device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0083] The input device 330 may be used to receive input digital or character information and generate key signal input related to user settings and function control of the electronic device. The output device 340 may include a display device such as a display screen.

[0084] Embodiment 4

[0085] Embodiment 4 of the present invention further provides a storage medium containing computer executable instructions, wherein the computer executable instructions are used to execute a water pump control method when executed by a computer processor, including:

[0086] Determine the current demand value of the phase current according to the speed deviation between the actual speed of the motor and the target speed;

[0087] In the control mode where the d-axis current is 0 in the rotating coordinate system, the phase current limit is determined according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value;

[0088] Determining a phase current target value according to the current demand value and the phase current limit value;

[0089] The voltage and current of the rotating coordinate system are determined according to the deviation between the phase current target value and the current actual value.

[0090] Of course, the computer executable instructions of a storage medium including computer executable instructions provided in an embodiment of the present invention are not limited to the operations of the method described above, but can also execute related operations in the water pump control method provided in any embodiment of the present invention.

[0091] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0092] It is worth noting that in the embodiment of the above-mentioned water pump control device, the various units and modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0093] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A water pump control method, characterized in that: include: Determine the current demand value of the phase current according to the speed deviation between the actual speed of the motor and the target speed; In the control mode where the d-axis current is 0 in the rotating coordinate system, the phase current limit is determined according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value; Determining a phase current target value according to the current demand value and the phase current limit value; The voltage and current of the rotating coordinate system are determined according to the deviation between the phase current target value and the current actual value.

2. The method according to claim 1, characterized in that: The determining of the phase current target value according to the current demand value and the phase current limit value comprises: When the current demand value at the actual speed of the motor is lower than the phase current limit value, determining the current demand value as the phase current target value; When the current demand value at the actual speed of the motor is higher than or equal to the phase current limit value, the phase current limit value is determined as the phase current target value.

3. The method according to claim 1, characterized in that After determining the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value, the method further includes: The voltage and current of the rotating coordinate system are converted into three-phase voltage based on inverse Park transformation and inverse Clark transformation and output to the motor.

4. The method according to claim 1, characterized in that: In the control mode in which the d-axis current is 0 in the rotating coordinate system, the phase current limit value is determined according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value, including: In the control mode where the d-axis current is 0 in the rotating coordinate system, based on the power balance equation of the motor, according to the actual motor speed, internal resistance, back electromotive force coefficient and the power limit value, the q-axis current value is determined and used as the phase current limit value.

5. The method according to claim 4, characterized in that In the control mode in which the d-axis current is 0 in the rotating coordinate system, based on the power balance equation of the motor, according to the actual motor speed, internal resistance, back electromotive force coefficient and the power limit value, the q-axis current value is determined and used as the phase current limit value, including: When the d-axis current is 0, determine the power balance equation of the motor; wherein, in the power balance equation, the power is related to the motor speed, internal resistance, back electromotive force coefficient and q-axis current; At the actual speed of the motor, the internal resistance and the back electromotive force coefficient are taken as constants to determine that there is a preset corresponding relationship between the power and the q-axis current; According to the preset corresponding relationship between power and q-axis current and the power limit value, the q-axis current value is calculated and used as the phase current limit value.

6. The method according to claim 5, characterized in that The internal resistance and back EMF coefficient are determined as follows: Under different pump operating conditions, the peak value and frequency of the phase current are collected to calculate the corresponding q-axis current I q and speed N s , and record the power at the water pump input; Under different pump operating conditions, the real-time variable q-axis current I of the driver is collected. q and speed N s , record the power P at the water pump input; Each group of data (N s (i) I q (i)) Substitute into the power balance equation and calculate the power for each set of data: in, and is the estimated internal resistance and back EMF coefficient; According to the least squares theory, the power of each group of data in the collected data and the square sum function of the power residual calculated by the corresponding speed and phase current are: When the function value is minimized, and It is the optimal estimated parameter of the internal resistance and back EMF coefficient that satisfies the power balance equation.

7. A water pump control device, characterized in that: include: A current demand value determination module is used to determine the current demand value of the phase current according to the speed deviation between the actual speed of the motor and the target speed; The phase current limit determination module is used to determine the phase current limit value according to the corresponding relationship between the power and the phase current at the actual speed of the motor and the power limit value in the control mode in which the d-axis current is 0 in the rotating coordinate system; A phase current target value determination module, used to determine the phase current target value according to the current demand value and the phase current limit value; The voltage and current determination module is used to determine the voltage and current of the rotating coordinate system according to the deviation between the phase current target value and the current actual value.

8. The device according to claim 7, characterized in that The phase current target value determination module is specifically used to: When the current demand value at the actual speed of the motor is lower than the phase current limit value, determining the current demand value as the phase current target value; When the current demand value at the actual speed of the motor is higher than or equal to the phase current limit value, the phase current limit value is determined as the phase current target value.

9. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the water pump control method as described in any one of claims 1-6.

10. A storage medium containing computer executable instructions, characterized in that: The computer executable instructions are used to execute the water pump control method as described in any one of claims 1 to 6 when executed by a computer processor.

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