Flow frequency ratio control method and device and medium

Abstract

The invention discloses a flow-frequency ratio control method and device and a medium, relates to the technical field of motor control, and provides a flow-frequency ratio control method for solving the problem that loop gain needs to be manually adjusted to adapt to load change in the starting stage of a permanent magnet synchronous motor at present. The change of the load is reflected through the included angle error between the virtual coordinate system and the actual coordinate system. And in combination with a current closed-loop strategy, the I / F reference current amplitude is adjusted in real time according to the change of the load, so that the permanent magnet synchronous motor always keeps working at a point with the maximum torque current ratio. Under the condition of low load, the current injected by the I / F can be reduced through current closed-loop regulation, and meanwhile, the injected current can be improved after the system load is increased, so that the motor is prevented from being out of step. In addition, the method is a control parameter self-tuning scheme capable of identifying load change and adapting to and adjusting injection current. Manual loop gain trial and error through an engineering experience method in an actual field can be avoided, and the efficiency and robustness of the whole motor system are improved.

Description

Technical Field

[0001] This application relates to the field of motor control technology, and in particular to a current-frequency ratio control method, device and medium. Background Technology

[0002] Current-to-frequency ratio (I / F) control is commonly used during the startup phase of permanent magnet synchronous motors because its closed-loop current characteristic effectively avoids current surges during startup. However, traditional I / F control, due to its fixed high-amplitude current input, cannot effectively improve system efficiency when the load decreases.

[0003] Currently, a method for closed-loop current regulation based on load angle has been proposed to adapt to scenarios with load changes. The load angle is calculated using the steady-state voltage equation, and the voltage error is obtained by manually adjusting the loop gain. Finally, the current is regulated in a closed loop based on this voltage error. However, this method has poor response to step changes in the system, and the gain requires continuous manual adjustment, resulting in poor robustness.

[0004] Therefore, those skilled in the art urgently need a current-frequency ratio control method to solve the problem that the loop gain needs to be manually adjusted to adapt to load changes during the startup phase of a permanent magnet synchronous motor. Summary of the Invention

[0005] The purpose of this application is to provide a current-frequency ratio control method, device, and medium to solve the problem that the loop gain needs to be manually adjusted to adapt to load changes during the startup phase of a permanent magnet synchronous motor.

[0006] To solve the above-mentioned technical problems, this application provides a current-to-frequency ratio control method, comprising:

[0007] The angular error between the virtual coordinate system and the actual coordinate system of the permanent magnet synchronous motor in the current-frequency ratio control is obtained; wherein, the virtual coordinate system is a two-phase rotating coordinate system generated based on the load characteristics and current-frequency ratio of the permanent magnet synchronous motor; the actual coordinate system is a two-phase rotating coordinate system estimated by an observer for the permanent magnet synchronous motor;

[0008] Using a preset angle reference value as the given quantity and the angle error as the feedback quantity, the current adjustment value is obtained through a closed-loop controller.

[0009] Determine the current reference value based on the current adjustment value and the initial current amplitude;

[0010] The current-frequency ratio of the permanent magnet synchronous motor is controlled based on the current reference value.

[0011] In one optional embodiment, when the q-axis is oriented in the two-phase rotating coordinate system of the permanent magnet synchronous motor, the current adjustment value includes: a q-axis current adjustment component; and the angle reference value is π / 2.

[0012] The process of obtaining the current regulation value through a closed-loop controller, using a preset angle reference value as a given quantity and the angle error as a feedback quantity, includes:

[0013] Using π / 2 as a given quantity and the angle error as a feedback quantity, the q-axis current adjustment component is obtained through a closed-loop controller.

[0014] The current reference value includes: a q-axis current reference component and a d-axis current reference component; wherein, the d-axis current reference component is 0;

[0015] Determining the current reference value based on the current adjustment value and the initial current amplitude includes:

[0016] The q-axis current reference component is determined based on the q-axis current adjustment component.

[0017] In one optional embodiment, when the d-axis is oriented in the two-phase rotating coordinate system of the permanent magnet synchronous motor, the current adjustment value includes: a d-axis current adjustment component; and the angle reference value is π / 2.

[0018] The process of obtaining the current regulation value through a closed-loop controller, using a preset angle reference value as a given quantity and the angle error as a feedback quantity, includes:

[0019] Using π / 2 as a given quantity and the angle error as a feedback quantity, the d-axis current adjustment component is obtained through a closed-loop controller.

[0020] The current reference value includes: a q-axis current reference component and a d-axis current reference component; wherein, the q-axis current reference component is 0;

[0021] Determining the current reference value based on the current adjustment value and the initial current amplitude includes:

[0022] The d-axis current reference component is determined based on the d-axis current adjustment component.

[0023] In one alternative embodiment, the closed-loop controller is a proportional-integral regulator;

[0024] The process of obtaining the current regulation value through a closed-loop controller, using a preset angle reference value as a given quantity and the angle error as a feedback quantity, includes:

[0025] The current regulation value is obtained through a closed-loop control system consisting of the proportional-integral regulator and the active power oscillation suppression loop.

[0026] In one optional embodiment, the process for determining the gain coefficient of the closed-loop control system includes:

[0027] The transfer function of the closed-loop control system is subjected to power-order merging and normalization to obtain the corresponding standard third-order polynomial as the first control expression.

[0028] Determine the necessary and sufficient stability conditions of the standard third-order polynomial according to the Roth criterion;

[0029] The minimum value of the proportional gain coefficient is determined based on the necessary and sufficient stability condition.

[0030] The minimum value of the proportional gain coefficient is taken as a preset multiple of the proportional gain coefficient of the closed-loop control system, and then substituted back into the standard third-order polynomial to determine the proportional gain coefficient and the integral gain coefficient.

[0031] In an alternative embodiment, bringing back the standard third-order polynomial to determine the proportional gain coefficient and the integral gain coefficient includes:

[0032] The transfer function of the closed-loop control system is configured into a fast pole and dominant second-order form to obtain the second control expression; wherein, the dominant second-order term of the second control expression includes a given dominant second-order objective and a dominant second-order frequency;

[0033] The second governing expression is converted into the form of a standard third-order polynomial to obtain the third governing expression;

[0034] By setting the coefficients of the corresponding power terms in the first and third control equations to be equal, the proportional gain coefficient and the integral gain coefficient can be obtained.

[0035] In one alternative embodiment, the dominant second-order target is any value between 0.6 and 0.8, and the dominant second-order frequency is any value between 20% and 40% of the current frequency ratio of the operating electrical angular frequency.

[0036] To address the aforementioned technical problems, this application also provides a current-to-frequency ratio control device, comprising:

[0037] An error acquisition module is used to acquire the angular error between the virtual coordinate system and the actual coordinate system of the permanent magnet synchronous motor in the current-frequency ratio control; wherein, the virtual coordinate system is a two-phase rotating coordinate system generated based on the load characteristics and current-frequency ratio of the permanent magnet synchronous motor; the actual coordinate system is a two-phase rotating coordinate system estimated by an observer for the permanent magnet synchronous motor;

[0038] The first adjustment module is used to obtain the current adjustment value through a closed-loop controller, using a preset angle reference value as the given quantity and the angle error as the feedback quantity.

[0039] The second adjustment module is used to determine the current reference value based on the current adjustment value and the initial current amplitude.

[0040] The current-frequency ratio control module is used to control the current-frequency ratio of the permanent magnet synchronous motor according to the current reference value.

[0041] To address the aforementioned technical problems, this application also provides a current-to-frequency ratio control device, comprising:

[0042] Memory, used to store computer programs;

[0043] A processor is configured to implement the flow ratio control method as described above when executing the computer program.

[0044] To address the aforementioned technical problems, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described flow-to-frequency ratio control method.

[0045] This application provides a current-to-frequency ratio (I / F) control method that reflects load changes through the angular error between the virtual and actual coordinate systems. Combined with a current closed-loop strategy, it adjusts the I / F reference current amplitude in real time according to load changes, ensuring the permanent magnet synchronous motor always operates at its maximum torque-to-current ratio. Under low load conditions, the I / F injected current can be reduced through current closed-loop regulation, while increasing the injected current as the system load increases to prevent motor step loss. Furthermore, this method is a self-tuning scheme for control parameters that can identify load changes and adapt to adjusting the injected current. It avoids the need for manual loop gain adjustments based on engineering experience in actual field operations, improving the efficiency and robustness of the entire motor system.

[0046] The frequency ratio control device and computer-readable storage medium provided in this application correspond to the above method and have the same effect. Attached Figure Description

[0047] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A flowchart of a current-to-frequency ratio control method provided in an embodiment of the present invention;

[0049] Figure 2 A schematic diagram illustrating an angular error between coordinate systems provided in an embodiment of the present invention;

[0050] Figure 3 A control block diagram of a closed-loop controller provided in an embodiment of the present invention;

[0051] Figure 4 A control block diagram of a load adaptive current-frequency ratio control system provided in an embodiment of the present invention;

[0052] Figure 5 This is a structural diagram of a current-to-frequency ratio control device provided in an embodiment of the present invention;

[0053] Figure 6 This is a structural diagram of another current-frequency ratio control device provided in an embodiment of the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0055] The core of this application is to provide a method, device, and medium for controlling the current-to-frequency ratio.

[0056] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] Currently, to address the issue that current-frequency ratio control (I / F control) fails to effectively improve system efficiency when the load decreases due to its fixed high-amplitude current input, a scheme using load angle for closed-loop current regulation has been proposed. However, this method calculates the load angle using the steady-state voltage equation, obtains the voltage error by manually adjusting the loop gain, and finally uses the voltage error to regulate the current in a closed loop. This approach has poor response to system step changes, requires continuous manual gain adjustment, and exhibits poor robustness.

[0058] To address the aforementioned problems, this application provides a current-to-frequency ratio control method, such as... Figure 1 As shown, it includes:

[0059] S1: Obtain the angular error between the virtual coordinate system and the actual coordinate system of the permanent magnet synchronous motor in the current-frequency ratio control.

[0060] The virtual coordinate system is a two-phase rotating coordinate system generated based on the load characteristics and current-frequency ratio of the permanent magnet synchronous motor; the actual coordinate system is a two-phase rotating coordinate system obtained by estimating the permanent magnet synchronous motor through an observer.

[0061] S2: Using a preset angle reference value as the given quantity and the angle error as the feedback quantity, the current regulation value is obtained through a closed-loop controller.

[0062] S3: Determine the current reference value based on the current adjustment value and the initial current amplitude.

[0063] S4: Perform current-frequency ratio control on the permanent magnet synchronous motor based on the current reference value.

[0064] Specifically, for step S1 above, the relationship between the virtual coordinate system and the actual coordinate system is as follows: Figure 2 As shown. Figure 2 In the diagram, the dq coordinate system (represented in green) is the virtual coordinate system under I / F; the d*-q* coordinate system represents the actual coordinate system estimated by the observer (represented in red); the α axis is the coordinate axis under the two-phase stationary coordinate system (represented by the black dashed line). θ e θ represents the angle between the actual coordinate system and the α-axis; r The α-axis represents the angle between the virtual coordinate system and the α-axis; δ represents the angular error between the actual coordinate system and the virtual coordinate system. The angular error δ can be expressed as:

[0065] (1);

[0066] To achieve the goal of the permanent magnet synchronous motor always operating at the maximum torque-to-current ratio during the I / F stage, under q-axis orientation, i.e., the d-axis current component i... d =0. At this point, the above requirement is met when the angle error δ = π / 2, which means setting a reference value for the angle error (the angle reference value in step S2) δ. ref =π / 2. Then, using the angle error δ and the angle reference value δ... ref The reference value I of the q-axis current is obtained by differential closed-loop regulation. q *

[0067] That is, this embodiment provides an optional implementation scheme for the specific implementation of step S2 above:

[0068] When orienting the q-axis in the two-phase rotating coordinate system of the permanent magnet synchronous motor, the current adjustment value includes: the q-axis current adjustment component, with an angle reference value of π / 2. Step S2 above specifically comprises:

[0069] S2-A: Using π / 2 as the given quantity and the angle error as the feedback quantity, the q-axis current adjustment component is obtained through a closed-loop controller.

[0070] The current reference value includes: the q-axis current reference component and the d-axis current reference component, where the d-axis current reference component is 0. Step S3 above specifically includes:

[0071] S3-A: Determine the q-axis current reference component based on the q-axis current adjustment component.

[0072] Similarly, the above logic also applies to d-axis orientation. In the case of d-axis orientation, i.e., the q-axis current component i... q =0. At this point, the above requirement is met when the angle error δ = π / 2, which means setting a reference value for the angle error (the angle reference value in step S2) δ. ref =π / 2. Then, using the angle error δ and the angle reference value δ... ref The reference value of the d-axis current is obtained by differential closed-loop regulation.

[0073] That is, this embodiment provides another optional implementation scheme for the specific implementation of step S2 above:

[0074] When orienting the d-axis in the two-phase rotating coordinate system of the permanent magnet synchronous motor, the current adjustment value includes: the d-axis current adjustment component, with an angle reference value of π / 2. Step S2 above specifically comprises:

[0075] S2-B: Using π / 2 as the given quantity and the angle error as the feedback quantity, the d-axis current adjustment component is obtained through a closed-loop controller.

[0076] The current reference value includes: the q-axis current reference component and the d-axis current reference component, where the q-axis current reference component is 0. Step S3 above specifically includes:

[0077] S3-B: Determine the d-axis current reference component based on the d-axis current adjustment component.

[0078] Since the underlying principle is exactly the same for both d-axis and q-axis orientation, the only difference lies in the current component used for closed-loop adjustment of the angle error. Therefore, for simplicity, the following explanation will use q-axis orientation and the adjustment of the q-axis current component through closed-loop angle error control as an example. This closed-loop adjustment can be achieved using proportional-integral (PI) control strategies, the purpose of which is to determine a d-axis current adjustment component I. q * To adjust the reference value i of the q-axis current component in I / F control. q *

[0079] For the angle error closed-loop regulation section, when a PI closed-loop control strategy is adopted, the control structure of the closed-loop controller (i.e., the proportional-integral controller) is as follows: Figure 3 As shown. At this time, the reference value i of the q-axis current component in the I / F control is... q * can be represented as:

[0080] (2);

[0081] Where I0 is the initial current amplitude. K p and Ki These are the proportional gain coefficient and the integral gain coefficient, respectively.

[0082] Therefore, it can be seen that as long as the control parameters (K) of the above closed-loop controller are designed... p and K i This method allows the motor system to adaptively adjust the current amplitude to operate at the maximum torque-to-current ratio operating point under any load condition. At this point, the control structure of the entire motor system's I / F control system can be as follows: Figure 4 As shown.

[0083] Figure 4 The I / F control system shown is an example with q-axis orientation. Figure 4 The control section to the left of the red dashed line is the load adaptive adjustment section corresponding to steps S1~S3 above, used to adaptively adjust the current reference value of the I / F control according to the actual load. Specifically, the reference value i for the d-axis current component is [value missing] when the q-axis is oriented. d *Take 0 directly, and obtain the reference value i of the q-axis current component that adapts to load changes through the above-mentioned load adaptive adjustment section. q * Figure 4 The PI controller highlighted in red is the closed-loop controller in step S2-A above. The proportional gain coefficient K of this PI control element also needs to be solved subsequently. p and integral gain coefficient K i .

[0084] It is important to note that the focus of this method is on the aforementioned load adaptive adjustment section. And for... Figure 4 The control structure to the right of the red dashed line represents the remaining control parts of the motor I / F control system. Specifically, this part converts the control parameters from current to voltage (i.e., u) through closed-loop control. d * and u q *); By collecting the three-phase current i of the permanent magnet synchronous motor (PMSM) a i b i c Then, the three-phase current is successively transformed from the three-phase stationary coordinate system (abc) to the two-phase rotating coordinate system (dq) through the abc-αβ transformation and the αβ-dq transformation as feedback quantities; voltage component u d * and u q *Transform to a two-phase stationary coordinate system using the dq-αβ transformation, i.e., u α * and u β Finally, a corresponding pulse width modulation (PWM) signal is generated by a PWM generator (SVPWM), and the permanent magnet synchronous motor is controlled by a two-level inverter.

[0085] As described above, this method utilizes the angular error between the virtual and actual coordinate systems to reflect load changes, thus providing a control scheme that uses closed-loop adjustment based on angular error to adaptively change the I / F reference current amplitude with load variations. Under this method, when the load decreases, the I / F injected current is reduced by adjusting the angular error to improve motor system efficiency; when the load increases, the I / F injected current is increased by adjusting the angular error to prevent motor step loss, ensuring it always operates at the maximum torque-to-current ratio operating point. Furthermore, this method can adaptively adjust the I / F reference current amplitude based on load adaptation, eliminating the need for technicians to manually adjust the loop gain on-site using engineering experience, thereby improving the overall efficiency and robustness of the motor system.

[0086] On the other hand, as can be seen from the above embodiments, this method achieves adaptive adjustment of the I / F reference current amplitude as the load changes through a closed-loop controller. This application does not limit the specific closed-loop control strategy used; any closed-loop control strategy, including PI control, can be employed. For various closed-loop control strategies, there are already mature technical solutions for determining the control parameters, so the above embodiments of this application have not elaborated on them. For example, taking q-axis orientation as an example, at this time, in i d =0, linearize the operating point, and δ ref If π / 2 is a constant reference, then we can obtain i d With δ ref The relationship between them:

[0087] (3);

[0088] From equation (3), the open-loop transfer function G of the closed-loop controller can be obtained. c (s) is:

[0089] (4);

[0090] In the formula, ω z This represents a defined frequency quantity, defined as follows: .

[0091] Furthermore, due to the inherent weak damping characteristics of I / F control, this application also provides a further embodiment to improve the stability of the motor system. Specifically, step S2 involves obtaining the current regulation value through a closed-loop control system composed of a proportional-integral regulator and an active power oscillation suppression loop. Wherein, after incorporating active power oscillation suppression, the transfer function G of the closed-loop controller... p (s) is:

[0092] (5);

[0093] In the formula, N p B is the number of pole pairs of the motor; J is the moment of inertia of the motor; m K1 is the friction coefficient of the motor; K1 is a defined coefficient, defined as... ; Let G(s) be the magnetic flux linkage of the motor; G(s) is the transfer function of the active power oscillation suppression loop, and its expression is shown below:

[0094] (6);

[0095] In the formula, K pf The gain coefficient of the active power oscillation suppression loop is assumed to be known; ω r T represents the rotor speed of the motor. L This represents the motor torque.

[0096] After incorporating current adaptive closed-loop regulation, the open-loop transfer function L(s) of the entire closed-loop controller can be expressed as:

[0097] (7);

[0098] The corresponding closed-loop characteristic equation is:

[0099] (8);

[0100] Once the gain coefficient of the PI control is determined, the transfer function of the PI controller can be obtained, completing the control design. Since PI control is a common closed-loop control strategy, there are currently several mature technical solutions for determining its gain coefficient; therefore, this embodiment will not elaborate on its determination principle and process. Furthermore, although the above embodiment incorporates active power oscillation suppression on top of PI control, the gain coefficient K of the active power oscillation suppression loop... pf It can be designed in advance and considered as known. Therefore, solving the transfer function of the closed-loop controller is essentially solving for the gain coefficient K of the PI control. p and K i To further illustrate the current-to-frequency ratio control method provided in this application, this embodiment presents a corresponding gain coefficient K after combining PI control with an active power oscillation suppression loop. p and K i Method for determining:

[0101] S51: The transfer function of the closed-loop control system is subjected to power-law merging and normalization to obtain the corresponding standard third-order polynomial as the first control expression.

[0102] S52: Determine the necessary and sufficient stability conditions for a standard third-order polynomial based on the Roth criterion.

[0103] S53: Determine the minimum value of the proportional gain coefficient based on the necessary and sufficient stability conditions.

[0104] S54: Take the preset multiple of the minimum value of the proportional gain coefficient as the proportional gain coefficient of the closed-loop control system, and substitute it back into the standard third-order polynomial to determine the proportional gain coefficient and the integral gain coefficient.

[0105] Specifically, step S51 involves substituting equations (5) to (7) into equation (8) and then merging them each time to obtain:

[0106] (9);

[0107] In the formula, α2, α1, and α0 are the coefficients of the quadratic term, the linear term, and the constant term, respectively. a1 and a0 are intermediate coefficients. , .

[0108] Normalize the above equation (9) to a standard third-order polynomial:

[0109] (10);

[0110] At this point, according to Roth's criterion, the necessary and sufficient condition for stability of equation (10) is A>0, B>0, C>0, and AB>C. Then we can obtain the relevant information about K. p The formula for the minimum value:

[0111] (11);

[0112] in, That is, K p The minimum value of K min K is an intermediate value used to simplify the formula on the left side of the equal sign in equation (11). p Pick The preset multiple. This embodiment does not limit the preset multiple; one optional scheme is to set the preset multiple to 2. At this time, K... p Substituting the expressions back into equations (9) and (10) above, the gain coefficient K can be obtained. p and K i .

[0113] However, based on the above embodiments, to further improve the convergence speed and damping of the entire closed-loop control system, this embodiment also provides a further implementation scheme. Step S54: Substituting back the standard third-order polynomial to determine the proportional gain coefficient and integral gain coefficient specifically includes:

[0114] S541: Arrange the transfer function of the closed-loop control system into a fast pole and dominant second-order form to obtain the second control expression; wherein, the dominant second-order term of the second control expression includes the given dominant second-order objective and dominant second-order frequency.

[0115] S542: Convert the second governing expression into the form of a standard third-order polynomial to obtain the third governing expression.

[0116] S543: Make the coefficients of the corresponding power terms in the first and third control equations equal, and solve for the proportional gain coefficient and integral gain coefficient.

[0117] That is, the standard third-order polynomial of equation (10) can be completed as:

[0118] (12);

[0119] In the formula, ζ is the dominant second-order objective, i.e., the damping ratio; ω n p is the dominant second-order frequency quantity. f for:

[0120] (13);

[0121] In this context, fast poles refer to poles far from the imaginary axis. Their presence can accelerate the initial response of the system and help improve the convergence speed. The dominant second-order component, determined by the closed-loop dominant poles, dictates the dynamic characteristics of the system. By appropriately configuring the parameters of the dominant second-order component (such as the damping ratio), the damping characteristics of the system can be adjusted. For example, adjusting the damping ratio ζ of the dominant second-order system can change the overshoot and oscillation of the system response, thereby improving the system's damping performance.

[0122] It should be noted that this embodiment is not limited to ζ and ω. n The specific value can be determined according to the actual damping performance requirements. In one optional embodiment: the dominant second-order target ζ is any value between 0.6 and 0.8, and the dominant second-order frequency ω n It is any value between 20% and 40% of the operating electrical angular frequency.

[0123] After obtaining equation (12), we can combine the coefficients of the corresponding power terms in equation (12) and equation (10) to form a system, which gives us:

[0124] (14);

[0125] Based on equation (14), the intermediate coefficient K can be obtained as follows:

[0126] (15);

[0127] The final gain coefficient of the closed-loop control system is:

[0128] (16);

[0129] As described above, this embodiment provides a scheme for determining the optimal gain coefficient of the PI controller in the load adaptive control section. Under the control of this gain coefficient, the motor system can be kept at the operating point of maximum torque-to-current ratio at all times. This improves the system efficiency under low load and reduces the probability of system synchronism loss under high load.

[0130] In the above embodiments, a method for controlling the frequency ratio has been described in detail. This application also provides an embodiment of a corresponding frequency ratio control device. It should be noted that this application describes the embodiment of the device from two perspectives: one is based on the functional modules, and the other is based on the hardware.

[0131] From the perspective of functional modules, such as Figure 5 As shown, this embodiment provides a current-to-frequency ratio control device, including:

[0132] Error acquisition module 11 is used to acquire the angle error between the virtual coordinate system and the actual coordinate system of the permanent magnet synchronous motor in the current-frequency ratio control; wherein, the virtual coordinate system is a two-phase rotating coordinate system generated based on the load characteristics and current-frequency ratio of the permanent magnet synchronous motor; the actual coordinate system is a two-phase rotating coordinate system obtained by estimating the permanent magnet synchronous motor through the observer.

[0133] The first adjustment module 12 is used to obtain the current adjustment value through a closed-loop controller, using a preset angle reference value as the given quantity and the angle error as the feedback quantity.

[0134] The second adjustment module 13 is used to determine the current reference value based on the current adjustment value and the initial current amplitude.

[0135] The current-frequency ratio control module 14 is used to control the current-frequency ratio of the permanent magnet synchronous motor according to the current reference value.

[0136] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0137] Figure 6 A structural diagram of a current-to-frequency ratio control device provided in another embodiment of this application is shown below. Figure 6 As shown, a current-to-frequency ratio control device includes: a memory 20 for storing computer programs;

[0138] The processor 21 is used to execute a computer program to implement the steps of a frequency ratio control method as described in the above embodiment.

[0139] The current-frequency ratio control device provided in this embodiment may include, but is not limited to, permanent magnet synchronous motor controllers, computers, etc.

[0140] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one of the following hardware forms: Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an Artificial Intelligence (AI) processor, which is used to handle computational operations related to machine learning.

[0141] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 20 is used to store at least the following computer program 201, which, after being loaded and executed by the processor 21, is capable of implementing the relevant steps of a streaming frequency ratio control method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, and the storage method may be temporary or permanent storage. The operating system 202 may include Windows, Unix, Linux, etc. The data 203 may include, but is not limited to, a streaming frequency ratio control method.

[0142] In some embodiments, a frequency ratio control device may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0143] Those skilled in the art will understand that Figure 6 The structure shown does not constitute a limitation on a frequency ratio control device and may include more or fewer components than shown.

[0144] This application provides a streaming frequency ratio control device, which includes a memory and a processor. When the processor executes a program stored in the memory, it can implement the following method: a streaming frequency ratio control method.

[0145] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above method embodiments.

[0146] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, 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 executes all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0147] The above provides a detailed description of a current-to-frequency ratio control method, apparatus, and medium provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

[0148] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A flow-to-frequency control method, characterized by, The method comprises: obtaining an angle error between a virtual coordinate system and an actual coordinate system of a permanent magnet synchronous motor in flow-frequency ratio control, wherein the virtual coordinate system is a two-phase rotating coordinate system calculated based on load characteristics and current-frequency ratio of the permanent magnet synchronous motor, and the actual coordinate system is a two-phase rotating coordinate system obtained by an observer; taking a preset angle reference value as a given quantity and the angle error as a feedback quantity to obtain a current adjustment value through a closed-loop controller; determining a current reference value according to the current adjustment value and an initial current amplitude; controlling the permanent magnet synchronous motor in flow-frequency ratio according to the current reference value.

2. The flow-to-frequency control method of claim 1, wherein In q-axis orientation in the two-phase rotating coordinate system of the permanent magnet synchronous motor, the current adjustment value comprises a q-axis current adjustment component, and the angle reference value is π / 2. The method of taking the preset angle reference value as the given quantity and the angle error as the feedback quantity to obtain the current adjustment value through the closed-loop controller comprises: taking π / 2 as the given quantity and the angle error as the feedback quantity to obtain the q-axis current adjustment component through the closed-loop controller. The current reference value comprises a q-axis current reference component and a d-axis current reference component, wherein the d-axis current reference component is 0. The method of determining the current reference value according to the current adjustment value and the initial current amplitude comprises: determining the q-axis current reference component according to the q-axis current adjustment component.

3. The flow-to-frequency control method of claim 1, wherein In d-axis orientation in the two-phase rotating coordinate system of the permanent magnet synchronous motor, the current adjustment value comprises a d-axis current adjustment component, and the angle reference value is π / 2. The method of taking the preset angle reference value as the given quantity and the angle error as the feedback quantity to obtain the current adjustment value through the closed-loop controller comprises: taking π / 2 as the given quantity and the angle error as the feedback quantity to obtain the d-axis current adjustment component through the closed-loop controller. The current reference value comprises a q-axis current reference component and a d-axis current reference component, wherein the q-axis current reference component is 0. The method of determining the current reference value according to the current adjustment value and the initial current amplitude comprises: determining the d-axis current reference component according to the d-axis current adjustment component.

4. The flow-to-frequency control method according to claim 2 or 3, characterized by, The closed-loop controller is a proportional-integral regulator. The method of taking the preset angle reference value as the given quantity and the angle error as the feedback quantity to obtain the current adjustment value through the closed-loop controller comprises: obtaining the current adjustment value through a closed-loop control system composed of the proportional-integral regulator and an active power oscillation suppression loop.

5. The flow-to-frequency control method of claim 4, wherein, The gain coefficient determination process of the closed-loop control system comprises: performing power-time merging and normalization processing on a transfer function of the closed-loop control system to obtain a corresponding standard third-order polynomial as a first control formula; determining a necessary and sufficient stability condition of the standard third-order polynomial according to Routh criterion; determining a minimum value of a proportional gain coefficient according to the necessary and sufficient stability condition; taking a preset multiple of the minimum value of the proportional gain coefficient as the proportional gain coefficient of the closed-loop control system, and bringing back the standard third-order polynomial to determine the proportional gain coefficient and an integral gain coefficient.

6. The flow-to-frequency control method of claim 5, wherein, The taking the standard third-order polynomial to determine the proportional gain coefficient and the integral gain coefficient comprises: fitting a transfer function of the closed-loop control system into a fast pole and a dominant second-order form to obtain a second control formula; wherein the dominant second-order term of the second control formula comprises a given dominant second-order target and a dominant second-order frequency; converting the second control formula into a standard third-order polynomial form to obtain a third control formula; equating the coefficients of corresponding power terms of the first control formula and the third control formula to obtain the proportional gain coefficient and the integral gain coefficient.

7. The flow-to-frequency control method of claim 6, wherein, The dominant second-order target is any value between 0.6 and 0.8, and the dominant second-order frequency is any value between 20% and 40% of the flow-to-frequency ratio operating angular frequency.

8. A flow-to-frequency control device, characterized by, The method comprises the steps of: an error acquisition module configured to acquire an angle error between a virtual coordinate system and an actual coordinate system of a permanent magnet synchronous motor in flow-to-frequency ratio control; wherein the virtual coordinate system is a two-phase rotating coordinate system generated based on load characteristics and a current-to-frequency ratio of the permanent magnet synchronous motor; and the actual coordinate system is a two-phase rotating coordinate system obtained by an observer estimating the permanent magnet synchronous motor; a first adjustment module configured to take a preset angle reference value as a given quantity and the angle error as a feedback quantity to obtain a current adjustment value through a closed-loop controller; a second adjustment module configured to determine a current reference value according to the current adjustment value and an initial current amplitude; a flow-to-frequency ratio control module configured to perform flow-to-frequency ratio control on the permanent magnet synchronous motor according to the current reference value.

9. A flow-to-frequency control device, characterized by, The method comprises the steps of: a memory configured to store a computer program; a processor configured to execute the computer program to implement the steps of the flow-to-frequency ratio control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer program is stored on the computer readable storage medium, and when executed by the processor, the computer program implements the steps of the flow-to-frequency ratio control method according to any one of claims 1 to 7.

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