Control method and device of network-forming equipment, controller, equipment and medium

Abstract

The invention discloses a control method and device of network construction type equipment, a controller, equipment and a medium, and belongs to the technical field of wind power. The method comprises the following steps: based on impedance from a grid-side converter to a power grid, a preset inertia time constant and a preset angular velocity parameter, obtaining a damping coefficient of an active power synchronization ring by using second-order system characteristics of the active power synchronization ring; performing active power synchronization operation according to the damping coefficient, the inertia time constant and the control parameter of the active power synchronization loop to obtain an internal potential phase of the network construction type equipment; performing reactive power closed-loop control operation according to the control parameters of the reactive power loop to obtain an internal potential amplitude of the network construction type equipment; and controlling the operation of the grid-side converter by using a PWM signal generated based on the internal potential phase and the internal potential amplitude. According to the embodiment of the invention, the safety and reliability of the power system can be improved.

Description

Technical Field

[0001] The present application belongs to the field of wind power technology, and in particular relates to a control method, device, controller, equipment and medium for a grid-type device. Background Art

[0002] With the development of clean energy technologies such as wind power generation technology and photovoltaic power generation technology, the proportion of clean energy equipment such as wind turbines and photovoltaic equipment in the power system has gradually increased, making the power system including clean energy equipment and power grids have a trend of reduced inertia and weakened strength. In order to cope with power demand and environmental pressure, a grid control strategy can be adopted to use grid-building equipment to provide damping and inertia for the power system, so that it can respond quickly when the grid frequency changes to support the stability of the power system.

[0003] However, due to differences in power system structure, the grid strength in different areas of the power system will be different. This will result in different active power response characteristics of the grid-building equipment under different grid strengths when the grid frequency changes, and inconsistent support characteristics for the grid, which will cause the power system to be at risk of instability and reduce the safety and reliability of the power system. Summary of the invention

[0004] The embodiments of the present application provide a control method, device, controller, equipment and medium for a networking device, which can improve the safety and reliability of the power system.

[0005] In a first aspect, an embodiment of the present application provides a control method for a meshing device, wherein the meshing device includes a grid-side converter, which is configured to be connected to a grid; the method includes: based on the impedance between the grid-side converter and the grid, a preset inertia time constant and a preset angular velocity parameter, using the second-order system characteristics of the active power synchronization loop, obtaining the damping coefficient of the active power synchronization loop; performing calculations based on the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop to obtain the internal potential phase of the meshing device; performing reactive power closed-loop control calculations based on the control parameters of the reactive power loop to obtain the internal potential amplitude of the meshing device; and controlling the operation of the grid-side converter using a PWM signal generated based on the internal potential phase and the internal potential amplitude.

[0006] In some possible embodiments, based on the impedance between the grid-side converter and the grid, a preset inertia time constant and a preset angular velocity parameter, the damping coefficient of the active power synchronization loop is obtained by utilizing the second-order system characteristics of the active power synchronization loop, including: obtaining a target intermediate parameter according to the impedance between the grid-side converter and the grid, the inertia time constant, the angular velocity parameter and the second-order system characteristics; determining a target damping ratio corresponding to the target intermediate parameter in the damping correspondence table in a pre-established damping correspondence table, the damping correspondence table including a correspondence between the damping ratio and the value range of the intermediate parameter; obtaining the damping coefficient according to the target damping ratio, the angular velocity parameter, the inertia time constant, the impedance from the grid-side converter to the grid and the second-order system characteristics.

[0007] In some possible embodiments, in a pre-established damping correspondence, before determining the target damping ratio corresponding to the target intermediate parameter in the damping correspondence table, it also includes: obtaining multiple different damping ratios, and calculating the value ranges of the intermediate parameters corresponding to the multiple different damping ratios according to the second-order system characteristics and the multiple different damping ratios; and establishing a damping correspondence table according to the multiple different damping ratios and the corresponding value ranges of the intermediate parameters.

[0008] In some possible embodiments, in a pre-established damping correspondence table, a target damping ratio corresponding to the target intermediate parameter in the damping correspondence table is determined, including: in the damping correspondence table, determining a value range of an intermediate parameter within which the target intermediate parameter falls; and determining the damping ratio corresponding to the value range of the intermediate parameter within which the intermediate parameter falls in the damping correspondence table as the target damping ratio.

[0009] In some possible embodiments, the angular velocity parameter includes an active power synchronization loop cutoff angular velocity and a rated angular velocity of the power grid.

[0010] In some possible embodiments, the control parameters of the active power synchronization loop include the measured active power of the grid-side converter, the reference active power of the grid-side converter, the internal potential angular velocity, and the rated angular velocity of the grid;

[0011] Active power synchronization operation is performed according to the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop to obtain the internal potential phase of the network-forming device, including: obtaining the torque increment of the network-forming device according to the difference between the reference active power and the measured active power, and the internal potential angular velocity; obtaining the angular velocity increment according to the torque increment, the inertia time constant and the damping coefficient; and obtaining the internal potential phase by integrating the sum of the rated angular velocity and the angular velocity increment.

[0012] In some possible embodiments, the control parameters of the reactive power loop include the measured reactive power of the grid-side converter, the reference reactive power of the grid-side converter, and the rated voltage of the grid-type device.

[0013] A reactive power closed-loop control operation is performed according to the control parameters of the reactive power loop to obtain the internal potential amplitude of the meshing type device, including: performing a closed-loop control operation on the difference between the reference reactive power and the measured reactive power to obtain the voltage increment of the meshing type device, the closed-loop control operation including at least one of a proportional operation, an integral operation, and a differential operation; and the sum of the voltage increment and the rated voltage is determined as the internal potential amplitude.

[0014] In a second aspect, an embodiment of the present application provides a control device for a meshing type device, which is applied to the meshing type device, wherein the meshing type device includes a grid-side converter, which is configured to be connected to a power grid; the device includes: a damping coefficient setting module, which is used to obtain the damping coefficient of the active power synchronization loop based on the impedance between the grid-side converter and the power grid, a preset inertia time constant and a preset angular velocity parameter, using the second-order system characteristics of the active power synchronization loop; a phase determination module, which is used to perform active power synchronization operations according to the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop to obtain the internal potential phase of the meshing type device; an amplitude determination module, which is used to perform reactive power closed-loop control operations according to the control parameters of the reactive power loop to obtain the internal potential amplitude of the meshing type device; and a control module, which is used to control the operation of the grid-side converter using a PWM signal generated based on the internal potential phase and the internal potential amplitude.

[0015] In a third aspect, an embodiment of the present application provides a controller for a networking device, comprising: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the control method for the networking device of the first aspect is implemented.

[0016] In a fourth aspect, an embodiment of the present application provides a meshing device, comprising: a grid-side converter, wherein the output end of the grid-side converter is configured to be connected to a power grid; and a controller of the meshing device of the third aspect, connected to the grid-side converter.

[0017] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the control method of the networking device of the first aspect is implemented.

[0018] The embodiment of the present application provides a control method, device, controller, equipment and medium for a meshing device, which can obtain the damping coefficient of the active power synchronization loop based on the impedance, inertia time constant and angular velocity parameters from the grid-side converter to the grid, and the damping coefficient matches the impedance between the grid-side converter and the grid. According to the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop, the internal potential phase of the meshing device is obtained. According to the control parameters of the reactive power loop, the internal potential amplitude of the meshing device is obtained. In view of the different impedances between the grid-side converter and the grid, different damping coefficients of the active power synchronization loop are obtained, and the internal potential phase is affected by the damping coefficient, so that the PWM signal generated by combining the internal potential phase and the internal potential amplitude controls the grid-side converter, and the predictability of the active power response characteristics of the meshing device under different grid strengths is achieved, so that the active response characteristics of the meshing device under different grid strengths are consistent or tend to be consistent, reducing or even avoiding the risk of instability of the power system, and improving the safety and reliability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic diagram of the structure of an example of a networking device provided in an embodiment of the present application;

[0021] Figure 2 A flow chart of a method for controlling a networking device provided in one embodiment of the present application;

[0022] Figure 3 A schematic diagram of an example of active power response of a grid-connected device under different SCRs obtained by using a control method with a fixed damping coefficient;

[0023] Figure 4 A schematic diagram of an example of active power response of a network device obtained by using the control method for self-tuning the damping coefficient in an embodiment of the present application;

[0024] Figure 5 A flowchart of a method for controlling a networking device provided in another embodiment of the present application;

[0025] Figure 6 A schematic diagram of an example of active power loop synchronous control provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of an example of reactive power loop control provided in an embodiment of the present application;

[0027] Figure 8 A schematic diagram of an example of networked device control provided in an embodiment of the present application;

[0028] Fig. 9 A schematic diagram of the structure of a control device for a networking device provided in one embodiment of the present application;

[0029] Fig.10 A schematic diagram of the structure of a controller of a networking device provided in one embodiment of the present application;

[0030] Fig.11 A schematic diagram of the structure of a networking device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0031] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are intended only to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application. It should be noted that the acquisition, storage, use, and processing of information and data in the embodiments of the present application are authorized by users or relevant agencies, in compliance with the relevant provisions of national laws and regulations.

[0032] With the development of clean energy technologies such as wind power generation technology and photovoltaic power generation technology, the proportion of clean energy equipment such as wind turbines and photovoltaic equipment in the power system has gradually increased, which has led to a trend of reduced inertia and weakened strength of the power system including clean energy equipment and power grids. In order to cope with power demand and environmental pressure, a grid control strategy can be adopted to use grid-building equipment to provide damping and inertia for the power system, so that when the grid frequency changes, it can respond quickly and support the stability of the power system. However, due to the differences in the structure of the power system, the grid strengths in different areas of the power system will be different, and the grid control simulation damping characteristics of the grid-building equipment will use a fixed damping coefficient, which makes the active power response characteristics of the grid-building equipment inconsistent and unpredictable under different grid strengths, affecting the grid performance of the power system. When the grid frequency changes, the active power response characteristics of the grid-building equipment under different grid strengths are different, and the support characteristics of the grid are inconsistent, which makes the power system instability risk, reducing the safety and reliability of the power system.

[0033] The present application provides a control method, device, controller, equipment and medium for a meshing device, which can obtain the damping coefficient under different grid strengths according to the second-order system characteristics of the active power synchronization loop, and obtain the internal potential phase of the meshing device according to the obtained damping coefficient and other control parameters of the active power synchronization loop. The internal potential amplitude of the meshing device is obtained according to the control parameters of the reactive power loop. Therefore, a modulation signal for controlling the grid-side converter of the meshing device is generated according to the internal potential phase and internal potential amplitude of the meshing device to control the grid-side converter. The damping coefficient is set according to the grid strength, so that the active power response characteristics of the meshing device under different grid strengths are consistent or tend to be consistent, thereby improving the performance of the active control of the meshing device, eliminating the risk of instability caused by the inconsistent active power response characteristics of the meshing device under different grid strengths, and thus improving the safety and reliability of the power system.

[0034] For ease of understanding, here is a brief introduction to networking devices. Figure 1 A schematic diagram of an example of a network-building device provided in an embodiment of the present application, such as Figure 1 As shown, the grid-type device in the embodiment of the present application may include a simulated virtual energy source 11 and a grid-side converter 12. The energy source 11 may be electrically connected to the grid-side converter 12 via a DC bus, and the grid-side converter 12 is connected to the power grid 21. The energy source 11 may include but is not limited to energy storage batteries, wind turbines, photovoltaic equipment, etc. The grid-side converter 12 includes a plurality of switching devices. For example, the grid-side converter may include a plurality of insulated-gate bipolar transistors (IGBT) or other types of switching devices. The current conversion function of the grid-side converter 12 is achieved by the coordination of the conduction and shutdown of a plurality of switching devices. Figure 1 The inductance Lf in represents the inductance of the grid-side converter, PCC is the grid connection point between the grid-forming device and the grid 21, and the impedance Zg represents the line impedance of the line between the grid-forming device and the grid 21. In the embodiment of the present application, when the grid-forming device is in an offline state, that is, the grid-forming device is in a shutdown state, the grid-side converter 12 can be controlled by active power synchronization loop control combined with reactive power loop control, so that the active power response characteristics of the grid-forming device under different grid strengths are consistent or tend to be consistent.

[0035] The control method, device, controller, equipment and medium of the networking device provided in this application are described below respectively.

[0036] A first aspect of the present application provides a control method for a meshed device, which is applied to the meshed device. The control method for the meshed device can be executed by a control device, a controller, etc. of the meshed device, and is not limited here. Figure 2A flow chart of a control method for a networking device provided in an embodiment of the present application, such as Figure 2 As shown, the control method of the networking device may include steps S301 to S304.

[0037] In step S301, based on the impedance between the grid-side converter and the grid, a preset inertia time constant and a preset angular velocity parameter, and using the second-order system characteristics of the active power synchronization loop, a damping coefficient of the active power synchronization loop is obtained.

[0038] In the embodiment of the present application, the strength of the power grid can be represented by the short-circuit ratio (SCR), which can be the ratio of the three-phase short-circuit capacity of the access busbar to which the grid-side converter is electrically connected to the grid to the capacity of the grid-forming device, and the three-phase short-circuit capacity can be the short-circuit capacity provided by the energy source simulated by the grid-forming device. The inertia time constant can describe the ability of the grid-forming device to release kinetic energy to resist the change of the grid frequency in the case of power imbalance. In the embodiment of the present application, the inertia time constant is set in advance according to the scene, demand, etc. The angular velocity parameter may include some parameters related to the angular velocity given in the control process of the grid-forming device. In some examples, the angular velocity parameter may include the active power synchronization ring cut-off angular velocity and the rated angular velocity of the grid. The active power synchronization ring cut-off angular velocity and the rated angular velocity of the grid can be set according to the scene, demand, experience, etc. For example, the rated angular velocity of the grid can also be called the rated angular velocity of the grid voltage, and the rated angular velocity of the grid can be 314rad / s, i.e., 314 radians / second, but is not limited thereto.

[0039] The grid-type equipment uses an active power synchronization loop to simulate the inertia and damping characteristics of the synchronous generator, and obtains the internal potential phase of the generator set according to the calculation. The closed-loop transfer function of the active power synchronization loop can be reflected by the ratio of the change in the measured active power of the grid-side converter to the change in the reference active power of the grid-side converter, as shown in the following formula (1):

[0040]

[0041] in, is the change of the measured active power of the grid-side converter; is the change of reference active power of the grid-side converter; ω N is the rated angular velocity of the power grid; K x is the inverse of the impedance between the grid-side converter and the grid; T J is the inertia time constant; D is the damping coefficient of the active power synchronization loop. From the above formula (1), it can be obtained that the closed-loop transfer function of the active power synchronization loop is a typical second-order system transfer function. Correspondingly, the active power synchronization loop has a second-order system characteristic.

[0042] The second-order system characteristics are related to the impedance, inertia time constant, angular velocity parameter and damping coefficient. Correspondingly, the second-order system characteristics of the active power synchronization loop are related to the impedance, inertia time constant, angular velocity parameter and damping coefficient of the active power synchronization loop between the grid-side converter and the grid. Through the relationship between the impedance, inertia time constant, angular velocity parameter and damping coefficient of the active power synchronization loop between the grid-side converter and the grid in the second-order system characteristics, the damping coefficient corresponding to the active power synchronization loop can be obtained according to the known impedance, inertia time constant and angular velocity parameters from the grid-side converter to the grid.

[0043] In step S302, active power synchronization operation is performed according to the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop to obtain the internal potential phase of the network-forming device.

[0044] The control parameters of the active power synchronization loop are used to assist in the control operation of the active power synchronization loop. In some examples, the control parameters of the active power synchronization loop may include but are not limited to the measured active power of the grid-side converter, the reference active power of the grid-side converter, the internal potential angular velocity and the rated angular velocity of the power grid. The measured active power of the grid-side converter may be the measured active power output of the grid-side converter. The reference active power of the grid-side converter may be the active power of the grid-side converter issued by the controller of the grid-forming device. The internal potential angular velocity is the internal potential angular velocity of the grid-forming device, and further, the internal potential angular velocity may be the internal potential angular velocity obtained by the grid-forming device through the active power synchronization loop. The active power synchronization loop is controlled by adopting virtual synchronous control technology so that the grid-side converter has the inertia, damping and other characteristics of the synchronous generator. When the grid-side converter has the inertia, damping and other characteristics of a synchronous generator, active power synchronization operations are performed according to the damping coefficient, inertia time constant, control parameters of the active power synchronization loop, etc., to obtain the internal potential phase of the grid-forming device. Active power synchronization operations may include difference operations, division operations, integration operations, summation operations, etc. Active power synchronization operations such as difference operations, division operations, integration operations, and summation operations may be performed on the damping coefficient, inertia time constant, and control parameters of the active power synchronization loop to convert the internal potential phase.

[0045] In step S303, a reactive power closed-loop control operation is performed according to the control parameters of the reactive power loop to obtain the internal potential amplitude of the grid-forming device.

[0046] The control parameters of the reactive power loop are used to assist in the reactive power closed-loop control operation. In some examples, the control parameters of the reactive power loop may include, but are not limited to, the measured reactive power of the grid-side converter, the reference reactive power of the grid-side converter, and the rated voltage of the grid-type equipment. The measured reactive power of the grid-side converter may specifically be the measured reactive power output by the grid-side converter. The reference reactive power of the grid-side converter may specifically be the reactive power sent by the controller to the grid-side converter. The reactive power closed-loop control operation may include differential operation, proportional operation, integral operation, differential operation, etc. The control parameters of the reactive power loop may be subjected to reactive power closed-loop control operations such as differential operation, proportional operation, integral operation, differential operation, etc., and converted to obtain the internal potential amplitude. The internal potential amplitude may also be referred to as the internal potential voltage.

[0047] In step S304, the operation of the grid-side converter is controlled by using a PWM signal generated based on the internal potential phase and the internal potential amplitude.

[0048] The internal potential phase and internal potential amplitude can be modulated to generate a pulse width modulation (PWM) signal. The PWM signal can be transmitted to the grid-side converter, and the PWM signal is used to control the on and off of the switching device in the grid-side converter, thereby realizing the control of the grid-side converter.

[0049] In the embodiment of the present application, the damping coefficient of the active power synchronization loop can be obtained based on the impedance, inertia time constant and angular velocity parameters from the grid-side converter to the grid, and the damping coefficient matches the impedance from the grid-side converter to the grid. According to the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop, the internal potential phase of the grid-forming device is obtained. According to the control parameters of the reactive power loop, the internal potential amplitude of the grid-forming device is obtained. In view of the different impedances from the grid-side converter to the grid, different damping coefficients of the active power synchronization loop are obtained, and the internal potential phase is affected by the damping coefficient, so as to control the grid-side converter by combining the PWM signal generated by the internal potential phase and the internal potential amplitude, so as to realize the predictability of the active power response characteristics of the grid-forming device under different grid strengths, so that the active power response characteristics of the grid-forming device under different grid strengths are consistent or tend to be consistent, reduce or even avoid the risk of instability of the power system, and improve the safety and reliability of the power system.

[0050] In order to reflect the effect of the control method of the meshing type device in the embodiment of the present application, under the same test conditions, the active power obtained by the control method using a fixed damping coefficient and the active power obtained by the control method of the meshing type device in the embodiment of the present application were monitored respectively, and the difference in the active power response characteristics of the two control methods was obtained. Figure 3 Schematic diagram of an example of active power response of grid-connected equipment under different SCRs obtained by using a control method with a fixed damping coefficient. Figure 4 This is a schematic diagram of an example of the active power response of the networking equipment obtained by using the control method of the damping coefficient self-tuning in the embodiment of the present application. The test condition is that the active power of the networking equipment steps from 0kW to 3000kW. Figure 3 and Figure 4 In the figure, the horizontal axis represents time, the vertical axis represents active power value (unit: kW), and the purple curve, yellow curve, red curve, and blue curve correspond to the scenarios of short circuit ratio of 20, short circuit ratio of 10, short circuit ratio of 5, and short circuit ratio of 2, respectively. The active power response characteristics can be reflected by the active power response time. Figure 3 The active power response time required for the active power values ​​of the curves corresponding to different short-circuit ratios to change and reach stability is inconsistent, and when the grid strength is different (that is, different short-circuit ratios), the active power response time of the grid-forming equipment also varies greatly. When the grid strength is lower, the active power response time required for the grid-forming equipment to reach a steady state is longer. Figure 4 The active power response time required for the active power values ​​of the curves corresponding to different short-circuit ratios to change and reach stability is slightly different and tends to be consistent. In summary, the control method of the meshing device provided in the embodiment of the present application can improve the consistency of the active power response characteristics of the meshing device under different short-circuit ratios, i.e., different grid strengths, so that the power system including the meshing device is safer and more stable.

[0051] In some embodiments, a pre-established damping correspondence table may be used to obtain a damping coefficient, thereby implementing active power synchronization calculation according to the damping coefficient. Figure 5 This is a flow chart of a control method for a networking device provided in another embodiment of the present application. Figure 5 and Figure 2 The difference is that Figure 2 Step S301 in the above example can be specifically broken down into Figure 5 Steps S3011 to S3013 in Figure 2 Step S302 in the above example can be specifically broken down into Figure 5 Steps S3021 to S3024 in Figure 2 Step S303 in the above example can be specifically broken down into Figure 5 Step S3031 and step S3032 in .

[0052] In step S3011, target intermediate parameters are obtained according to the impedance between the grid-side converter and the grid, the inertia time constant, the angular velocity parameters, and the second-order system characteristics.

[0053] The target intermediate parameter is an intermediate parameter calculated based on the impedance between the grid-side converter and the grid, the inertia time constant, and the angular velocity parameter. Under the condition of the second-order system characteristics, the target intermediate parameter is negatively correlated with the inverse of the impedance between the grid-side converter and the grid, and the target intermediate parameter is positively correlated with the inertia time constant. In some examples, the angular velocity parameter may include the active power synchronization loop cutoff angular velocity and the rated angular velocity of the grid, the active power synchronization loop cutoff angular velocity is positively correlated with the target intermediate parameter, and the rated angular velocity of the grid is negatively correlated with the target intermediate parameter. For example, the target intermediate parameter can be calculated according to the following formula (2):

[0054]

[0055] Among them, K α is the target intermediate parameter; ω b is the active power synchronization ring cut-off angular velocity; T J is the inertia time constant; ω N is the rated angular velocity of the power grid; K x It is the reciprocal of the impedance between the grid-side converter and the grid.

[0056] In step S3012, in a pre-established damping correspondence table, a target damping ratio corresponding to the target intermediate parameter in the damping correspondence table is determined.

[0057] The intermediate parameter has a corresponding relationship with the damping ratio, and according to the characteristics of the second-order system, the damping ratio and the damping coefficient also have a correlation. A damping corresponding relationship table can be established in advance, and the damping corresponding relationship table can characterize the corresponding relationship between the intermediate parameter and the damping ratio. The damping corresponding relationship table may include a corresponding relationship between the damping ratio and the value range of the intermediate parameter. For example, the damping corresponding relationship table can be expressed by the following formula (3):

[0058]

[0059] Where ξ is the damping ratio; ξ1, ξ2, …, ξ n is the damping ratio of different values; K β1 ≤K α <K β2 , K β2 ≤K α <K β3 , …, K β(n-1) ≤K α <K βn The damping correspondence table can also be expressed in a table, which will not be specifically described here.

[0060] In some examples, before executing step S3012, a damping correspondence table may be established in advance. Specifically, a plurality of different damping ratios may be obtained, and the value ranges of the intermediate parameters corresponding to the plurality of different damping ratios may be calculated based on the second-order system characteristics and the plurality of different damping ratios; a damping correspondence table between the intermediate parameters and the damping ratios may be established based on the plurality of different damping ratios and the value ranges of the corresponding intermediate parameters. The second-order system characteristics include the relationship between the intermediate parameters and the damping ratios. When the corresponding relationship between the intermediate parameters and the damping ratios is known, the corresponding intermediate parameters may be calculated using the known damping ratios. In order to form the value ranges of the plurality of intermediate parameters, a plurality of different damping ratios may be selected first. For each damping ratio, the intermediate parameters corresponding to the damping ratio may be calculated using the second-order system characteristics. The intermediate parameters corresponding to the plurality of damping ratios may be summarized to obtain the corresponding relationship between the damping ratio and the value range of the intermediate parameters. For example, the relationship between the damping ratio and the intermediate parameter in the second-order system characteristics may be as shown in the following formula (4):

[0061]

[0062] Among them, K β is the intermediate parameter; ξ is the damping ratio. If ξ1 in the above formula (3) is substituted into the above formula (4), the K β The value range should be [K β1 ,K β2 ), similarly, substituting ξ2 in equation (3) into equation (4) to calculate K β The value range should be [K β2 ,K β3 By establishing a correspondence between multiple damping ratios and the value range of the intermediate parameter calculated according to the multiple damping ratios and the second-order system characteristics, a damping correspondence table between the intermediate parameter and the damping ratio can be established.

[0063] In some examples, the value range of the intermediate parameter into which the target intermediate parameter falls can be determined in the damping correspondence table of the intermediate parameter and the damping ratio; in the damping correspondence table, the damping ratio corresponding to the value range into which the intermediate parameter falls is determined as the target damping ratio. For example, as shown in the above formula (4), after obtaining the target intermediate parameter K α After that, if K α Fall into [K β1 ,K β2 ), in the damping correspondence table between the intermediate parameter and the damping ratio, the damping ratio corresponding to the parameter range is ξ1, then the target damping ratio can be determined to be ξ1; if K α Fall into [K β2 ,K β3), in the damping correspondence table of the intermediate parameter and the damping ratio, the damping ratio corresponding to the parameter range is ξ2, and the target damping ratio is determined to be ξ2. It is more convenient and quick to use the damping correspondence table of the intermediate parameter and the damping ratio to find the target damping ratio corresponding to the target intermediate parameter.

[0064] In other examples, each time the target intermediate parameter is obtained, the corresponding damping ratio may be calculated according to the relationship between the damping ratio and the intermediate parameter in the second-order system characteristics and the target intermediate parameter, and the corresponding damping ratio may be determined as the target damping ratio. The relationship between the damping ratio and the intermediate parameter in the second-order system characteristics may be referred to the relevant description in the above embodiment, which will not be repeated here.

[0065] In step S3013, a damping coefficient is obtained according to the target damping ratio, the angular velocity parameter, the inertia time constant, the impedance from the grid-side converter to the grid, and the second-order system characteristics.

[0066] The second-order system characteristics include the functional relationship between the damping ratio, angular velocity parameter, inertia time constant, impedance from the grid-side converter to the grid and the damping coefficient. When the functional relationship and the damping ratio, angular velocity parameter, inertia time constant and impedance from the grid-side converter to the grid are known, the corresponding damping coefficient can be calculated. In the second-order system characteristics, the damping ratio, angular velocity parameter, inertia time constant and damping coefficient are positively correlated, and the impedance from the grid-side converter to the grid is negatively correlated with the damping coefficient. For example, the damping coefficient can be calculated according to the following formula (5):

[0067]

[0068] Where D is the damping coefficient; ξ is the target damping ratio; ω N is the rated angular velocity of the power grid; K x is the inverse of the impedance from the grid-side converter to the grid; T J is the inertia time constant.

[0069] In step S3021, the torque increment of the meshing device is obtained according to the difference between the reference active power and the measured active power, and the internal potential angular velocity.

[0070] The difference between the reference active power and the measured active power can represent the difference between the active power actually output by the grid-side converter and the reference active power. The difference can be divided by the internal potential angular velocity to convert the active power difference into a torque increment, and the torque increment can be used for the next calculation.

[0071] In step S3022, the angular velocity increment is obtained according to the torque increment, the inertia time constant and the damping coefficient.

[0072] According to the inertia time constant and the damping coefficient, a mathematical model describing the inertia and damping characteristics can be obtained. The torque increment is used as the input of the mathematical model with inertia and damping characteristics to obtain the output angular velocity increment.

[0073] In step S3023, the sum of the rated angular velocity and the angular velocity increment is integrated to obtain the internal potential phase.

[0074] For example, Figure 6 A schematic diagram of an example of active power loop synchronous control provided in an embodiment of the present application is shown as follows: Figure 6 As shown, the reference active power and measured active power The difference between the internal potential and the angular velocity ω * Perform division operation to obtain the result of the operation, which is the torque increment. Then use the result of the operation as a mathematical model The output of the mathematical model is the angular velocity increment Δω, where T J is the inertia time constant, D is the damping coefficient, and s is the Laplace operator. N Add them together and integrate the sum to get the internal potential phase θ, Figure 6 In For integral operation.

[0075] In step S3031, a closed-loop control operation is performed on the difference between the reference reactive power and the measured reactive power to obtain a voltage increment of the grid-forming device.

[0076] The closed-loop control operation includes at least one of a proportional operation, an integral operation, and a derivative operation. For example, the closed-loop control operation can be implemented as a proportional operation, an integral operation, a proportional-integral operation, or a proportional-integral-derivative operation. The difference between the reference reactive power and the measured reactive power is used as the input of the closed-loop control operation, and the output of the closed-loop control operation is the voltage increment of the network-forming device.

[0077] In step S3032, the sum of the voltage increment and the rated voltage is determined as the internal potential amplitude.

[0078] For example, Figure 7 A schematic diagram of an example of reactive power loop control provided in an embodiment of the present application is shown as follows: Figure 7 As shown, the reference reactive power Q ref The measured reactive power Q meas The difference is used as the input of the closed-loop control operation. The output of the closed-loop control operation is the voltage increment ΔU. The voltage increment is compared with the rated voltage U of the network-forming equipment. * The sum of is determined as the internal potential amplitude U.

[0079] Figure 8 A schematic diagram of an example of networked device control provided in an embodiment of the present application, Figure 8 The structure of the networking device in Figure 1 , I will not go into details here. Figure 8 As shown, the internal potential phase θ and the internal potential amplitude U are modulated by signals to obtain a PWM signal, which can be input to the grid-side converter 12 to control the coordination of the on and off of the switching devices in the grid-side converter 12 to control the grid-side converter so that the active power response characteristics of the grid-forming equipment under different grid strengths (i.e., different short-circuit ratios) are consistent or tend to be consistent. The active power response characteristics of the grid-forming equipment here are consistent or tend to be consistent, which may refer to the difference between the active power response characteristics of the grid-forming equipment under different grid strengths within the preset standard range. The preset standard range can be set according to the scene, demand, experience, etc., and is not limited here.

[0080] A second aspect of the present application provides a control device for a meshed device, which is applied to the meshed device. The meshed device includes a grid-side converter, and the grid-side converter is configured to be connected to a power grid. Fig. 9 A schematic diagram of the structure of a control device for a networking device provided in an embodiment of the present application is shown in FIG. Fig. 9 As shown, the control device 400 of the meshing device may include a damping coefficient setting module 401, a phase determination module 402, an amplitude determination module 403 and a control module 404.

[0081] The damping coefficient setting module 401 can be used to obtain the damping coefficient of the active power synchronization loop based on the impedance between the grid-side converter and the grid, the preset inertia time constant and the preset angular velocity parameter, and using the second-order system characteristics of the active power synchronization loop.

[0082] The phase determination module 402 may be used to perform active power synchronization calculation according to the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop to obtain the internal potential phase of the network-forming device.

[0083] The amplitude determination module 403 may be used to perform reactive power closed-loop control operations according to the control parameters of the reactive power loop to obtain the internal potential amplitude of the network-forming device.

[0084] The control module 404 may be configured to control the operation of the grid-side converter by using a PWM signal generated based on the internal potential phase and the internal potential amplitude.

[0085] In some embodiments, the damping coefficient setting module 401 can be specifically used to: obtain a target intermediate parameter according to the impedance between the grid-side converter and the grid, the inertia time constant, the angular velocity parameter and the second-order system characteristics; determine a target damping ratio corresponding to the target intermediate parameter in the damping correspondence table in a pre-established damping correspondence table, the damping correspondence table including a correspondence between the damping ratio and the value range of the intermediate parameter; obtain a damping coefficient according to the target damping ratio, the angular velocity parameter, the inertia time constant, the impedance between the grid-side converter and the grid and the second-order system characteristics.

[0086] In some examples, the control device 400 of the networking device may further include a relationship table generation module. The relationship table generation module may be used to: obtain multiple different damping ratios, calculate and obtain the value ranges of the intermediate parameters corresponding to the multiple different damping ratios according to the second-order system characteristics and the multiple different damping ratios; and establish a damping correspondence relationship table according to the multiple different damping ratios and the corresponding value ranges of the intermediate parameters.

[0087] In some examples, the damping coefficient adjustment module 401 can be specifically used to: determine the value range of the intermediate parameter within which the target intermediate parameter falls in the damping correspondence table; and determine the damping ratio corresponding to the value range of the intermediate parameter within which the intermediate parameter falls in the damping correspondence table as the target damping ratio.

[0088] In some examples, the angular velocity parameters include an active power synchronization loop cutoff angular velocity and a rated angular velocity of the grid.

[0089] In some embodiments, the control parameters of the active power synchronization loop include the measured active power of the grid-side converter, the reference active power of the grid-side converter, the internal potential angular velocity, and the rated angular velocity of the grid. The phase determination module 402 can be specifically used to: obtain the torque increment of the grid-forming device according to the difference between the reference active power and the measured active power, and the internal potential angular velocity; obtain the angular velocity increment according to the torque increment, the inertia time constant, and the damping coefficient; and perform an integral operation on the sum of the rated angular velocity and the angular velocity increment to obtain the internal potential phase.

[0090] In some embodiments, the control parameters of the reactive power loop include the measured reactive power of the grid-side converter, the reference reactive power of the grid-side converter, and the rated voltage of the grid-type device. The amplitude determination module 403 can be specifically used to: perform a closed-loop control operation on the difference between the reference reactive power and the measured reactive power to obtain a voltage increment of the grid-type device, wherein the closed-loop control operation includes at least one of a proportional operation, an integral operation, and a differential operation; and determine the sum of the voltage increment and the rated voltage as the internal potential amplitude.

[0091] It should be noted that the control device 400 of the networking device is a device corresponding to the control method of the above-mentioned networking device. All implementation methods in the above-mentioned method embodiments are applicable to the embodiments of the device and can achieve the same technical effects, which will not be repeated here.

[0092] The third aspect of the present application also provides a controller for a networking device. Fig.10 A schematic diagram of the structure of a controller of a networking device provided in an embodiment of the present application, such as Fig.10 As shown, the controller 500 of the networking device includes a memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0093] In some examples, the processor 502 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0094] The memory 501 may include a read-only memory (ROM), a random access memory (RAM), a disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Therefore, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the control method of the networking device in the embodiment of the present application.

[0095] The processor 502 runs a computer program corresponding to the executable program code by reading the executable program code stored in the memory 501, so as to implement the control method of the networking device in the above embodiment.

[0096] In some examples, the controller 500 of the networking device may further include a communication interface 503 and a bus 504. Fig.10 As shown, the memory 501, the processor 502, and the communication interface 503 are connected via a bus 504 and communicate with each other.

[0097] The communication interface 503 is mainly used to realize the communication between the modules, devices, units and / or equipment in the embodiment of the present application. The communication interface 503 can also be used to access input devices and / or output devices.

[0098] The bus 504 includes hardware, software, or both, coupling the components of the controller 500 of the networking device to each other. By way of example and not limitation, the bus 504 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a Memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-E) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses or a combination of two or more of the above. Where appropriate, the bus 504 may include one or more buses. Although embodiments of the present application describe and illustrate a particular bus, the present application contemplates any suitable bus or interconnect.

[0099] A fourth aspect of the present application provides a networking device, Fig.11 A schematic diagram of the structure of a networking device provided in an embodiment of the present application. Fig.11 and Figure 1 The difference is that Fig.11 The illustrated meshing device also includes a controller 13 of the meshing device. The controller 13 of the meshing device is connected to the grid-side converter, and can execute the control method of the meshing device in the first aspect of the embodiment. For details, please refer to the relevant contents in the above embodiments, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here. In some examples, the meshing device may include but is not limited to wind turbines, photovoltaic equipment, etc.

[0100] In a fifth aspect, the present application provides a computer-readable storage medium, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the control method of the networking device in the above-mentioned embodiment can be implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here. Among them, the above-mentioned computer-readable storage medium may include a non-transitory computer-readable storage medium, such as a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc., which is not limited here.

[0101] An embodiment of the present application provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the control method of the networking device in the above embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0102] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. For device embodiments, controller embodiments, networking device embodiments, computer-readable storage medium embodiments, and computer program product embodiments, the relevant parts can refer to the description part of the method embodiment. The present application is not limited to the specific steps and structures described above and shown in the figures. Those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application. In addition, for the sake of brevity, a detailed description of known method technologies is omitted here.

[0103] The above reference is according to the method of the embodiment of the present application, the flow chart of the device (system) and the computer program product and / or the block diagram described various aspects of the present application.It should be understood that each square box in the flow chart and / or the block diagram and the combination of each square box in the flow chart and / or the block diagram can be realized by computer program instructions.These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the realization of the function / action specified in one or more square boxes of the flow chart and / or the block diagram.Such a processor can be but is not limited to a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit.It can also be understood that each square box in the block diagram and / or the flow chart and the combination of the square boxes in the block diagram and / or the flow chart can also be realized by the dedicated hardware that performs the specified function or action, or can be realized by the combination of dedicated hardware and computer instructions.

[0104] Those skilled in the art should understand that the above embodiments are exemplary rather than restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on the study of the drawings, the specification and the claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other devices or steps; the quantifier "one" does not exclude multiple; the terms "first" and "second" are used to indicate names rather than to indicate any specific order. Any figure marks in the claims should not be understood as limiting the scope of protection. The functions of multiple parts appearing in the claims can be implemented by a single hardware or software module. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

Claims

1. A control method for a networking device, characterized in that: The grid-type device includes a grid-side converter, and the grid-side converter is configured to be connected to a power grid; the method includes: Based on the impedance between the grid-side converter and the grid, the preset inertia time constant and the preset angular velocity parameter, and using the second-order system characteristics of the active power synchronization ring, a damping coefficient of the active power synchronization ring is obtained; Performing active power synchronization calculation according to the damping coefficient, the inertia time constant and the control parameter of the active power synchronization loop to obtain the internal potential phase of the network-forming device; Performing reactive power closed-loop control calculation according to the control parameters of the reactive power loop to obtain the internal potential amplitude of the network-forming device; The grid-side converter is controlled to operate by using a PWM signal generated based on the internal potential phase and the internal potential amplitude.

2. The method according to claim 1, characterized in that The method of obtaining the damping coefficient of the active power synchronization ring based on the impedance between the grid-side converter and the grid, the preset inertia time constant and the preset angular velocity parameter and utilizing the second-order system characteristics of the active power synchronization ring comprises: Obtaining a target intermediate parameter according to the impedance between the grid-side converter and the grid, the inertia time constant, the angular velocity parameter, and the second-order system characteristic; Determining a target damping ratio corresponding to the target intermediate parameter in a pre-established damping correspondence table, wherein the damping correspondence table includes a correspondence between the damping ratio and the value range of the intermediate parameter; The damping coefficient is obtained according to the target damping ratio, the angular velocity parameter, the inertia time constant, the impedance between the grid-side converter and the grid, and the second-order system characteristics.

3. The method according to claim 2, characterized in that In the pre-established damping correspondence, before determining the target damping ratio corresponding to the target intermediate parameter in the damping correspondence table, the method further includes: Acquire a plurality of different damping ratios, and calculate, according to the second-order system characteristics and the plurality of different damping ratios, obtain value ranges of intermediate parameters corresponding to the plurality of different damping ratios; The damping correspondence table is established according to the multiple different damping ratios and the value ranges of the corresponding intermediate parameters.

4. The method according to claim 2, characterized in that: The step of determining, in a pre-established damping correspondence table, a target damping ratio corresponding to the target intermediate parameter in the damping correspondence table comprises: In the damping correspondence table, determining a value range of the intermediate parameter within which the target intermediate parameter falls; The damping ratio corresponding to the value range of the intermediate parameter within which the intermediate parameter falls in the damping correspondence table is determined as the target damping ratio.

5. The method according to claim 2, characterized in that: The angular velocity parameters include the active power synchronization loop cut-off angular velocity and the rated angular velocity of the power grid.

6. The method according to claim 1, characterized in that The control parameters of the active power synchronization loop include the measured active power of the grid-side converter, the reference active power of the grid-side converter, the internal potential angular velocity and the rated angular velocity of the grid; The active power synchronization operation is performed according to the damping coefficient, the inertia time constant and the control parameter of the active power synchronization loop to obtain the internal potential phase of the network-forming device, including: Obtaining a torque increment of the networking device according to a difference between the reference active power and the measured active power, and the internal potential angular velocity; Obtaining an angular velocity increment according to the torque increment, the inertia time constant and the damping coefficient; The internal potential phase is obtained by integrating the sum of the rated angular velocity and the angular velocity increment.

7. The method according to claim 1, characterized in that The control parameters of the reactive power loop include the measured reactive power of the grid-side converter, the reference reactive power of the grid-side converter and the rated voltage of the grid-type device; The reactive power closed-loop control operation is performed according to the control parameters of the reactive power loop to obtain the internal potential amplitude of the network-forming device, including: Performing a closed-loop control operation on the difference between the reference reactive power and the measured reactive power to obtain a voltage increment of the network-forming device, wherein the closed-loop control operation includes at least one of a proportional operation, an integral operation, and a differential operation; The sum of the voltage increment and the rated voltage is determined as the internal potential amplitude.

8. A control device for a networking device, characterized in that: Applied to a grid-type device, the grid-type device comprising a grid-side converter, the grid-side converter being configured to be connected to a grid; The device comprises: A damping coefficient setting module, used to obtain the damping coefficient of the active power synchronization ring based on the impedance between the grid-side converter and the grid, a preset inertia time constant and a preset angular velocity parameter, and using the second-order system characteristics of the active power synchronization ring; A phase determination module, used to perform active power synchronization calculation according to the damping coefficient, the inertia time constant and the control parameters of the active power synchronization loop to obtain the internal potential phase of the network-forming device; An amplitude determination module is used to perform reactive power closed-loop control calculation according to the control parameters of the reactive power loop to obtain the internal potential amplitude of the network-forming device; A control module is used to control the operation of the grid-side converter by using a PWM signal generated based on the internal potential phase and the internal potential amplitude.

9. A controller for a networking device, characterized in that: include: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the control method of the networking device according to any one of claims 1 to 7 is implemented.

10. A networking device, characterized in that: include: A grid-side converter, wherein an output end of the grid-side converter is configured to be connected to a grid; The controller of the grid-type device as described in claim 9 is connected to the grid-side converter.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the control method of the networking device according to any one of claims 1 to 7 is implemented.

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