Virtual synchronous machine multi-machine interconnection hierarchical compensation control method and device

Abstract

The present disclosure relates to a method and device for controlling multi-machine interconnection of a virtual synchronous machine. The method includes: establishing an interconnected inverter space model based on a preset interconnected inverter circuit, generating a residual generator for the inverter in the interconnected inverter; establishing a hierarchical compensation control architecture, generating a high-frequency disturbance compensation controller based on the residual generator; performing distributed optimization on the equivalent virtual impedance compensation control structure, generating a distributed optimized equivalent virtual impedance compensation controller; establishing a residual-based interconnected inverter hierarchical compensation control structure, and completing multi-machine interconnection hierarchical compensation control of a virtual synchronous machine based on robust residuals based on the residual-based interconnected inverter hierarchical compensation control structure. The present disclosure can suppress the influence of high-frequency disturbances on the output voltage of the inverter, and at the same time, can evenly distribute reactive power when line parameters are perturbed, without the need to collect load current, saving equipment costs.

Description

Technical Field

[0001] The present disclosure relates to the field of virtual synchronous machines, and in particular to a multi-machine interconnected hierarchical compensation control method for virtual synchronous machines. Background Art

[0002] In recent years, global carbon emissions have been increasing. To this end, my country has proposed the "dual carbon" goal and vigorously developed distributed renewable energy. The extensive application of distributed renewable energy and power electronic equipment has brought huge challenges to the safe and stable operation of the power system. Therefore, microgrids have come into being. In microgrids, distributed renewable energy is generally connected by inverters. Therefore, it is very important to maintain the safe and stable operation of interconnected inverters. It is of great significance to study and solve the problem of inverter interconnection in microgrids. However, the inverter has the characteristics of low inertia. When the microgrid is islanded, when there is load or inverter switching, unbalanced load, and nonlinear load in the load, high-frequency non-fundamental current will be introduced into the load current, causing the inverter output voltage to fluctuate. In addition, when the line parameters are perturbed, the traditional virtual synchronous machine control cannot make the reactive power evenly distributed. Therefore, it is necessary to develop a control strategy to suppress high-frequency disturbances in the inverter interconnection system and make the reactive power evenly distributed when the line parameters are perturbed.

[0003] In the prior art, for the high-frequency disturbance problems caused by load or inverter switching, unbalanced load, and nonlinear load, proportional-integral observers and slack variables can be introduced to improve the system's anti-disturbance and robustness, or a compensation control strategy for specific disturbances can be added to the controller to suppress high-frequency disturbances and reduce the impact of high-frequency disturbances on the inverter output voltage. In order to solve the problem that traditional virtual synchronous machine control cannot balance reactive power due to line parameter perturbations, the current mainstream approach is to optimize the virtual impedance based on a distributed consistency algorithm, collect the inverter load current, and superimpose the compensation voltage obtained by multiplying the load current by the optimized virtual impedance and the given voltage of the voltage loop controller to change the inverter output voltage, thereby balancing reactive power.

[0004] The method of introducing proportional integral observer and relaxation variable to suppress high-frequency disturbances is mainly aimed at a single inverter, without considering multiple inverters, and the commonly used compensation control strategy for specific disturbances can rarely suppress the high-frequency disturbances generated by load or inverter switching, unbalanced load, and nonlinear load at the same time. The virtual impedance method of consistency optimization requires the use of a current collector to collect the load current, which increases the equipment cost.

[0005] Therefore, one or more methods are needed to solve the above problems.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0007] The purpose of the present disclosure is to provide a method and device for controlling hierarchical compensation of multiple interconnected virtual synchronous machines, thereby overcoming one or more problems caused by limitations and defects of related technologies at least to a certain extent.

[0008] According to one aspect of the present disclosure, a method for controlling hierarchical compensation of multiple virtual synchronous machines interconnected is provided, comprising:

[0009] Based on a preset interconnected inverter circuit, an interconnected inverter space model is established, and based on the interconnected inverter space model, a residual generator of an inverter in the interconnected inverter is generated;

[0010] Establishing a hierarchical compensation control architecture, and solving a high-frequency disturbance compensation controller based on a residual generator based on the hierarchical compensation control architecture and the interconnected inverter space model, and generating a high-frequency disturbance compensation controller based on a residual generator;

[0011] Based on the hierarchical compensation control architecture and the interconnected inverter space model, an equivalent virtual impedance compensation control structure is distributedly optimized, and based on the distributed optimized equivalent virtual impedance compensation control structure, an equivalent virtual impedance compensation controller is solved to generate a distributed optimized equivalent virtual impedance compensation controller;

[0012] Based on the residual generator-based high-frequency disturbance compensation controller and the distributed optimized equivalent virtual impedance compensation controller, a residual-based interconnected inverter hierarchical compensation control structure is established, and based on the residual-based interconnected inverter hierarchical compensation control structure, multi-machine interconnected hierarchical compensation control of a virtual synchronous machine based on robust residual is completed.

[0013] In an exemplary embodiment of the present disclosure, the method further includes:

[0014] Based on the interconnected inverter space model, a residual generator including state estimates of inverters in the interconnected inverters, an observer gain matrix, residuals, and a coefficient matrix is ​​generated.

[0015] In an exemplary embodiment of the present disclosure, the method further includes:

[0016] A hierarchical compensation control architecture is established based on the high-frequency disturbance compensation controller at the physical layer and the distributed optimized equivalent virtual impedance compensation controller at the information layer.

[0017] In an exemplary embodiment of the present disclosure, the method further includes:

[0018] Design a high-frequency disturbance compensation controller at the physical layer to suppress high-frequency disturbances;

[0019] A distributed optimized equivalent virtual impedance compensation controller is designed based on the information layer to achieve equal distribution of reactive power.

[0020] In an exemplary embodiment of the present disclosure, the method further includes:

[0021] According to the information layer communication and consistency theory, based on the hierarchical compensation control architecture and the interconnected inverter space model, the equivalent virtual impedance compensation control structure is distributedly optimized to generate a distributed optimized equivalent virtual impedance compensation control structure;

[0022] Based on the distributed optimized equivalent virtual impedance compensation control structure, the equivalent virtual impedance compensation controller is solved to generate a distributed optimized equivalent virtual impedance compensation controller.

[0023] In an exemplary embodiment of the present disclosure, the method further includes:

[0024] Based on the distributed optimized equivalent virtual impedance compensation control structure, the output signal of the equivalent virtual impedance compensation controller is superimposed with the given signal of the voltage loop controller to generate a given signal;

[0025] Based on the given signal shown, the virtual impedance is optimized according to the information of the reactive power of the interconnected inverters to achieve the equal distribution of the reactive power.

[0026] In one aspect of the present disclosure, a multi-machine interconnection hierarchical compensation control device for virtual synchronous machines based on robust residual is provided, comprising:

[0027] A residual generator design module, used to establish an interconnected inverter space model based on a preset interconnected inverter circuit, and generate a residual generator of an inverter in the interconnected inverter based on the interconnected inverter space model;

[0028] A high-frequency disturbance compensation controller generation module is used to establish a hierarchical compensation control architecture, and based on the hierarchical compensation control architecture and the interconnected inverter space model, solve the high-frequency disturbance compensation controller based on the residual generator to generate a high-frequency disturbance compensation controller based on the residual generator;

[0029] An equivalent virtual impedance compensation controller generation module is used to perform distributed optimization on an equivalent virtual impedance compensation control structure based on a hierarchical compensation control architecture and the interconnected inverter space model, solve an equivalent virtual impedance compensation controller based on the distributed optimized equivalent virtual impedance compensation control structure, and generate a distributed optimized equivalent virtual impedance compensation controller;

[0030] A multi-machine interconnected hierarchical compensation control module is used to establish a residual-based interconnected inverter hierarchical compensation control structure based on the residual generator-based high-frequency disturbance compensation controller and the distributed optimized equivalent virtual impedance compensation controller, and complete the multi-machine interconnected hierarchical compensation control of the virtual synchronous machine based on robust residual based on the residual-based interconnected inverter hierarchical compensation control structure.

[0031] A virtual synchronous machine multi-machine interconnection hierarchical compensation control method in an exemplary embodiment of the present disclosure, wherein the method includes: based on a preset interconnected inverter circuit, establishing an interconnected inverter space model, generating a residual generator of the inverter in the interconnected inverter; establishing a hierarchical compensation control architecture, generating a high-frequency disturbance compensation controller based on the residual generator; performing distributed optimization on the equivalent virtual impedance compensation control structure, generating a distributed optimized equivalent virtual impedance compensation controller; establishing a residual-based interconnected inverter hierarchical compensation control structure, and completing the multi-machine interconnection hierarchical compensation control of the virtual synchronous machine based on robust residual based on the residual-based interconnected inverter hierarchical compensation control. The present disclosure can suppress the influence of high-frequency disturbances on the inverter output voltage, and at the same time can make the reactive power evenly distributed when the line parameters are perturbed, without the need to collect load current, saving equipment costs.

[0032] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and other features and advantages of the present disclosure will become more apparent by describing in detail example embodiments thereof with reference to the attached drawings.

[0034] Figure 1 A flowchart of a multi-machine interconnection hierarchical compensation control method for virtual synchronous machines according to an exemplary embodiment of the present disclosure is shown;

[0035] Figure 2 A schematic diagram of interconnected inverter topology of a virtual synchronous machine multi-machine interconnected hierarchical compensation control method according to an exemplary embodiment of the present disclosure is shown;

[0036] Figure 3 A general framework diagram of hierarchical compensation control of a virtual synchronous machine multi-machine interconnection hierarchical compensation control method according to an exemplary embodiment of the present disclosure is shown;

[0037] Figure 4 A high-frequency disturbance compensation principle structure diagram of a virtual synchronous machine multi-machine interconnection hierarchical compensation control method according to an exemplary embodiment of the present disclosure is shown;

[0038] Figure 5A distributed optimized equivalent virtual impedance compensation control structure diagram of a multi-machine interconnected hierarchical compensation control method for virtual synchronous machines according to an exemplary embodiment of the present disclosure is shown;

[0039] Figure 6 A residual-based interconnected inverter hierarchical compensation control structure diagram of a virtual synchronous machine multi-machine interconnected hierarchical compensation control method according to an exemplary embodiment of the present disclosure is shown;

[0040] Figure 7 A schematic block diagram of a multi-machine interconnected hierarchical compensation control device for virtual synchronous machines based on robust residual according to an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0041] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0042] In addition, the described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of the specific details, or other methods, components, materials, devices, steps, etc. may be adopted. In other cases, known structures, methods and devices, implementations, materials or operations are not shown or described in detail to avoid blurring the various aspects of the present disclosure.

[0043] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or these functional entities or parts of functional entities may be implemented in one or more software hardened modules, or these functional entities may be implemented in different networks and / or processor devices and / or microcontroller devices.

[0044] In this exemplary embodiment, a virtual synchronous machine multi-machine interconnection hierarchical compensation control method is first provided; Figure 1 As shown in , the virtual synchronous machine multi-machine interconnection hierarchical compensation control method may include the following steps:

[0045] Step S110, establishing an interconnected inverter space model based on a preset interconnected inverter circuit, and generating a residual generator of an inverter in the interconnected inverter based on the interconnected inverter space model;

[0046] Step S120, establishing a hierarchical compensation control architecture, and solving a high-frequency disturbance compensation controller based on a residual generator based on the hierarchical compensation control architecture and the interconnected inverter space model to generate a high-frequency disturbance compensation controller based on a residual generator;

[0047] Step S130, performing distributed optimization on the equivalent virtual impedance compensation control structure based on the hierarchical compensation control architecture and the interconnected inverter space model, solving the equivalent virtual impedance compensation controller based on the distributed optimized equivalent virtual impedance compensation control structure, and generating a distributed optimized equivalent virtual impedance compensation controller;

[0048] Step S140, based on the residual generator-based high-frequency disturbance compensation controller and the distributed optimized equivalent virtual impedance compensation controller, a residual-based interconnected inverter hierarchical compensation control structure is established, and based on the residual-based interconnected inverter hierarchical compensation control structure, multi-machine interconnected hierarchical compensation control of the virtual synchronous machine based on robust residual is completed.

[0049] A virtual synchronous machine multi-machine interconnection hierarchical compensation control method in an exemplary embodiment of the present disclosure, wherein the method includes: based on a preset interconnected inverter circuit, establishing an interconnected inverter space model, generating a residual generator of the inverter in the interconnected inverter; establishing a hierarchical compensation control architecture, generating a high-frequency disturbance compensation controller based on the residual generator; performing distributed optimization on the equivalent virtual impedance compensation control structure, generating a distributed optimized equivalent virtual impedance compensation controller; establishing a residual-based interconnected inverter hierarchical compensation control structure, and completing the multi-machine interconnection hierarchical compensation control of the virtual synchronous machine based on robust residual based on the residual-based interconnected inverter hierarchical compensation control. The present disclosure can suppress the influence of high-frequency disturbances on the inverter output voltage, and at the same time can make the reactive power evenly distributed when the line parameters are perturbed, without the need to collect load current, saving equipment costs.

[0050] Next, a virtual synchronous machine multi-machine interconnection hierarchical compensation control method in this example embodiment will be further described.

[0051] In step S110, an interconnected inverter space model may be established based on a preset interconnected inverter circuit, and a residual generator of an inverter in the interconnected inverter may be generated based on the interconnected inverter space model.

[0052] In the embodiment of this example, the method further includes:

[0053] Based on the interconnected inverter space model, a residual generator including state estimates of inverters in the interconnected inverters, an observer gain matrix, residuals, and a coefficient matrix is ​​generated.

[0054] In the embodiment of this example, establishing the state space model of the interconnected inverter includes:

[0055] like Figure 2 Middle,U i,i , U o,i ,I x,i ,I L,i , L f,i , C f,i 、r f,i , Z L,i are the three-phase bridge output voltage, output voltage, load current, filter inductor current, filter inductor, filter capacitor, equivalent internal resistance, and load impedance of the i-th inverter; L ij , R ij , Z ij ,I ij Line inductance, line resistance, line impedance, and circulating current between the ith inverter and the jth inverter respectively.

[0056] based on Figure 2 In the interconnected topology, the state space equation of the controlled object of the i-th inverter is:

[0057]

[0058] in

[0059]

[0060] Where: x i =[I Ldq,i ,U odq,i ] T is the state quantity; u i =[U idq,i ] T is the input quantity; d j =[I Ldq,j ,U odq,j ] T is the coupling disturbance; d x,i =[I xdq,i ] T is the disturbance input; y i =[U odq,i ] T is the output; X ij , Z ij =R ij +jX ij are the line inductance and line impedance between the i-th inverter and the j-th inverter respectively; ω is the fundamental angular frequency.

[0061] In the embodiment of this example, the observer-based residual generator design includes:

[0062] The residual generator T of the i-th inverter i The expression of (s) is

[0063]

[0064] Where: x^ i (s), L i 、r i (s), A i are the state estimator, observer gain matrix, residual, coefficient matrix, and ψ of the i-th inverter respectively. i =0 s,i equal.

[0065] In step S120, a hierarchical compensation control architecture may be established, and based on the hierarchical compensation control architecture and the interconnected inverter space model, a high-frequency disturbance compensation controller based on a residual generator may be solved to generate a high-frequency disturbance compensation controller based on a residual generator.

[0066] In the embodiment of this example, the method further comprises:

[0067] A hierarchical compensation control architecture is established based on the high-frequency disturbance compensation controller at the physical layer and the distributed optimized equivalent virtual impedance compensation controller at the information layer.

[0068] In the embodiment of this example, the method further comprises:

[0069] Design a high-frequency disturbance compensation controller at the physical layer to suppress high-frequency disturbances;

[0070] A distributed optimized equivalent virtual impedance compensation controller is designed based on the information layer to achieve equal distribution of reactive power.

[0071] In the embodiment of this example, the hierarchical compensation control architecture includes:

[0072] In order to solve the high-frequency disturbance and reactive power uneven distribution problems in interconnected inverters, this patent proposes a hierarchical compensation control strategy. Figure 3 As shown in the figure, a high-frequency disturbance compensation controller is designed at the physical layer to suppress high-frequency disturbances; a distributed optimized equivalent virtual impedance compensation controller is designed based on information layer communication to make reactive power evenly distributed.

[0073] Figure 3 Medium, d B,i (s), d H,i (s) are the fundamental disturbance and high-frequency disturbance of the i-th inverter respectively.

[0074] The expression of the controlled object of the i-th inverter is:

[0075]

[0076] The compensation control structure based on the residual generator can be obtained by Euler parameterization and left-right coprime decomposition. The input and output of the inverter are used as the input of the residual generator, and the output is the residual. The residual is used as the input of the compensation control and the compensation is output. The internal stable controller of the i-th inverter can be parameterized as:

[0077] u i (s) = u 0,i (s)+Q i (s)r i (s)

[0078] Where: u 0,i (s) is the output signal of the original controller of the i-th inverter; r i (s) = [r B,i (s),r H,i (s)] T , r B,i (s), r H,i (s) are the fundamental residual component and high-frequency residual component of the i-th inverter respectively; Q i (s) = [Q B,i (s),Q H,i (s)] is the compensation controller of the i-th inverter, Q B,i (s) is the distributed optimized virtual impedance controller of the information layer, through r B,i (s) drive, so that reactive power is evenly distributed, Q H,i (s) is a distributed disturbance compensation controller at the physical layer, which is implemented by r H,i (s) drive, inhibit d H,i (s).

[0079] r B,i (s) and r H,i (s) can be obtained by the following formula

[0080]

[0081] Where: R B,i (s), R H,i (s) are respectively the low-pass filter and the high-pass filter of the i-th inverter. In the embodiment of this example, the residual-based high-frequency disturbance compensation controller solution includes:

[0082] In view of the high-frequency disturbance problems caused by load or inverter switching, unbalanced load access, nonlinear load access, etc., a high-frequency disturbance compensation controller is designed from the perspective of disturbance cancellation. Figure 3 The high-frequency disturbance compensation control architecture of the interconnected inverter based on residual can be obtained by combining the grid-type inverter interconnection system controlled by the virtual synchronous machine with the residual error as follows: Figure 4 shown.

[0083] Depend on Figure 4 It can be seen that in order to avoid U i,i When passing through the filter, it is fed back to the controller, introducing a secondary disturbance to the controller. H,i The output signal of (s) is superimposed on the given signal of the current loop controller, Q H,i The output of (s) directly affects the high-frequency disturbance current I after passing through the complete current loop. H,i Make compensation.

[0084] Depend on Figure 4 It can be seen that in order to fully compensate for the disturbance cancellation, H,i Need to meet

[0085]

[0086] Then the Q of the i-th inverter is H,i The expression of (s) is

[0087]

[0088] in

[0089]

[0090] Where: K ip,i is the current loop proportional coefficient of the i-th inverter; T s is the sampling period; n is the multiple of the negative real part of the system poles in the residual generator pole assignment.

[0091] Then the Q of the i-th inverter is H,i The expression of (s) becomes

[0092]

[0093] in

[0094]

[0095] Q i,2 =Q i,3 =0

[0096] G q,i =(L f,i s+r f,i )(1.5T s s+1)+K ip,i

[0097] Where: G b =(τs+1), τ is a smaller compensation coefficient.

[0098] In step S130, the equivalent virtual impedance compensation control structure can be distributedly optimized based on the hierarchical compensation control architecture and the interconnected inverter space model, and the equivalent virtual impedance compensation controller can be solved based on the distributed optimized equivalent virtual impedance compensation control structure to generate a distributed optimized equivalent virtual impedance compensation controller.

[0099] In the embodiment of this example, the method further comprises:

[0100] According to the information layer communication and consistency theory, based on the hierarchical compensation control architecture and the interconnected inverter space model, the equivalent virtual impedance compensation control structure is distributedly optimized to generate a distributed optimized equivalent virtual impedance compensation control structure;

[0101] Based on the distributed optimized equivalent virtual impedance compensation control structure, the equivalent virtual impedance compensation controller is solved to generate a distributed optimized equivalent virtual impedance compensation controller.

[0102] In the embodiment of this example, the method further comprises:

[0103] Based on the distributed optimized equivalent virtual impedance compensation control structure, the output signal of the equivalent virtual impedance compensation controller is superimposed with the given signal of the voltage loop controller to generate a given signal;

[0104] Based on the given signal shown, the virtual impedance is optimized according to the information of the reactive power of the interconnected inverters to achieve the equal distribution of the reactive power.

[0105] In the embodiment of this example, in order to solve the problem of uneven distribution of reactive load, an equivalent virtual impedance controller is designed from the perspective of changing the given amount of the voltage loop controller. When line parameters are perturbed due to factors such as line aging and damage, the equivalent virtual impedance compensation controller is distributedly optimized based on information layer communication and consistency theory.

[0106] Combination Figure 3 The grid-type inverter interconnection system controlled by the virtual synchronous machine can obtain the equivalent virtual impedance compensation control principle structure of the information layer distributed optimization of the interconnected inverters as follows: Figure 5 shown.

[0107] Figure 5 In, G -1 Brd,i (s) represents the fundamental residual as input, the fundamental disturbance current estimate As the transfer function of the output; Z v,i is the virtual impedance of the i-th inverter. Figure 4It can be seen that in order to avoid introducing secondary disturbance into the controller, the output signal of the equivalent virtual impedance compensation controller is superimposed on the given signal of the voltage loop controller, the given signal is changed, and then the output signal is changed to make the reactive power evenly distributed.

[0108] Depend on Figure 5 It can be seen that the distributed optimized virtual impedance controller includes a residual generator, R B,i (s), Z v,i and G -1 Brd (s). Among them, G -1 Brd (s) is expressed as follows

[0109]

[0110] Based on the consensus algorithm, Z v,i It can be obtained by the following formula

[0111]

[0112] in

[0113]

[0114] Where N i is the set of inverters interconnected with the i-th inverter; Z v0,i , K r,i are the initial virtual impedance and integral coefficient of the i-th inverter respectively; a ij Indicates the communication relationship between inverters, a ij >0 means there is communication between inverter i and inverter j, otherwise a ij =0.

[0115] When the line parameters are perturbed, the virtual impedance will be optimized according to the reactive information of the local and adjacent inverters to match the perturbed line parameters and make the reactive power evenly distributed.

[0116] In step S140, a residual-based interconnected inverter hierarchical compensation control structure can be established based on the residual generator-based high-frequency disturbance compensation controller and the distributed optimized equivalent virtual impedance compensation controller, and based on the residual-based interconnected inverter hierarchical compensation control structure, multi-machine interconnected hierarchical compensation control of the robust residual-based virtual synchronous machine can be completed.

[0117] In this exemplary embodiment, if Figure 6As shown, on the basis of the control of the virtual synchronous machine of the interconnected inverter, a high-frequency disturbance compensation controller and a distributed optimized equivalent virtual impedance compensation controller are designed based on the residual generator, and a residual-based interconnected inverter hierarchical compensation control structure is obtained. Based on the residual-based interconnected inverter hierarchical compensation control structure, multi-machine interconnected hierarchical compensation control of the virtual synchronous machine based on robust residual is completed.

[0118] In the embodiment of this example, the present invention proposes a hierarchical compensation control strategy for the inverter interconnection system based on residuals to address the high-frequency disturbance problem caused by load or inverter switching, unbalanced load, nonlinear load, and reactive power unequal distribution problem caused by line parameter perturbation in the inverter interconnection system. Based on the traditional virtual synchronous machine control, this method introduces a high-frequency compensation controller and a distributed optimized equivalent virtual impedance compensation controller, aiming to suppress the high-frequency disturbance caused by load or inverter switching, unbalanced load, and nonlinear load, so that reactive power can be evenly distributed when the line parameters are perturbed. Compared with other methods, the advantages of this control strategy are: the proposed control structure can be combined with the virtual synchronous machine control of the inverter, which improves the control performance of the system. There is no need to collect disturbance current, and the compensation controller is driven by residual error to output compensation signal for compensation; the designed high-frequency disturbance compensation controller can effectively suppress high-frequency disturbances caused by load or inverter switching, unbalanced load access, nonlinear load access, etc., and is easy to solve; the designed distributed optimized equivalent virtual impedance compensation controller does not need to obtain the specific parameters of the line, and can achieve compensation effect when the line parameters are perturbed, so that reactive power is evenly distributed, and the design is simple.

[0119] In the embodiment of this example, the present invention solves the high-frequency current disturbance problem caused by load disturbance and the reactive power unequal distribution problem caused by uneven distribution of reactive load in the grid-type inverter interconnection system controlled by the virtual synchronous machine. The virtual synchronous machine multi-machine interconnection hierarchical compensation control method is implemented as follows: First, a state space model including load current disturbance and circulating current disturbance is established based on the inverter interconnection topology to analyze the high-frequency disturbance and reactive power unequal distribution problems in the system. Secondly, a residual generator is designed based on the state space model of the inverter interconnection system, and the residual generated by the residual generator is respectively passed through low-pass and high-pass filters to obtain the fundamental residual component and the high-frequency residual component. Then, a physical layer high-frequency disturbance compensation controller is designed from the perspective of disturbance cancellation to suppress high-frequency disturbances. At the same time, an equivalent virtual impedance compensation controller is designed, and its consistency is optimized based on the information layer communication between the interconnected inverters, so that the reactive power output by the inverter can also be evenly distributed when the line parameters are perturbed.

[0120] It should be noted that, although the steps of the method in the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0121] In addition, in this exemplary embodiment, a virtual synchronous machine multi-machine interconnection hierarchical compensation control device based on robust residual is also provided. Figure 7 As shown, the virtual synchronous machine multi-machine interconnection hierarchical compensation control device 200 based on robust residual may include: a residual generator design module 210, a high-frequency disturbance compensation controller generation module 220, an equivalent virtual impedance compensation controller generation module 230 and a multi-machine interconnection hierarchical compensation control module 240. Among them:

[0122] A residual generator design module 210, for establishing an interconnected inverter space model based on a preset interconnected inverter circuit, and generating a residual generator of an inverter in the interconnected inverter based on the interconnected inverter space model;

[0123] A high-frequency disturbance compensation controller generation module 220 is used to establish a hierarchical compensation control architecture, and based on the hierarchical compensation control architecture and the interconnected inverter space model, solve the high-frequency disturbance compensation controller based on the residual generator to generate a high-frequency disturbance compensation controller based on the residual generator;

[0124] An equivalent virtual impedance compensation controller generation module 230 is used to perform distributed optimization on an equivalent virtual impedance compensation control structure based on a hierarchical compensation control architecture and the interconnected inverter space model, solve an equivalent virtual impedance compensation controller based on the distributed optimized equivalent virtual impedance compensation control structure, and generate a distributed optimized equivalent virtual impedance compensation controller;

[0125] The multi-machine interconnected hierarchical compensation control module 240 is used to establish a residual-based interconnected inverter hierarchical compensation control structure based on the residual generator-based high-frequency disturbance compensation controller and the distributed optimized equivalent virtual impedance compensation controller, and complete the multi-machine interconnected hierarchical compensation control of the virtual synchronous machine based on robust residual based on the residual-based interconnected inverter hierarchical compensation control structure.

[0126] The specific details of each of the above-mentioned virtual synchronous machine multi-machine interconnected hierarchical compensation control device modules based on robust residuals have been described in detail in a corresponding virtual synchronous machine multi-machine interconnected hierarchical compensation control method, so they will not be repeated here.

[0127] It should be noted that, although several modules or units of a multi-machine interconnected hierarchical compensation control device 200 for virtual synchronous machines based on robust residuals are mentioned in the above detailed description, such division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units for embodiment.

[0128] In addition, the above-mentioned figures are only schematic illustrations of the processes included in the method according to an exemplary embodiment of the present invention, and are not intended to be limiting. It is easy to understand that the processes shown in the above-mentioned figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0129] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are to be considered as exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims.

[0130] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A virtual synchronous machine multi-machine interconnection hierarchical compensation control method, characterized in that: The method comprises: Based on a preset interconnected inverter circuit, an interconnected inverter space model is established, and based on the interconnected inverter space model, a residual generator of an inverter in the interconnected inverter is generated; A hierarchical compensation control architecture is established, and based on the hierarchical compensation control architecture and the interconnected inverter space model, a high-frequency disturbance compensation controller based on a residual generator is solved to generate a high-frequency disturbance compensation controller based on a residual generator; a hierarchical compensation control architecture is established based on a high-frequency disturbance compensation controller at the physical layer and a distributed optimized equivalent virtual impedance compensation controller at the information layer; a high-frequency disturbance compensation controller is designed at the physical layer to suppress high-frequency disturbances; a distributed optimized equivalent virtual impedance compensation controller is designed based on the information layer to achieve equal distribution of reactive power; Based on the hierarchical compensation control architecture and the interconnected inverter space model, an equivalent virtual impedance compensation control structure is distributedly optimized, and based on the distributed optimized equivalent virtual impedance compensation control structure, an equivalent virtual impedance compensation controller is solved to generate a distributed optimized equivalent virtual impedance compensation controller; Based on the residual generator-based high-frequency disturbance compensation controller and the distributed optimized equivalent virtual impedance compensation controller, a residual-based interconnected inverter hierarchical compensation control structure is established, and based on the residual-based interconnected inverter hierarchical compensation control structure, multi-machine interconnected hierarchical compensation control of a virtual synchronous machine based on robust residual is completed.

2. The method according to claim 1, characterized in that The method further comprises: Based on the interconnected inverter spatial model, a residual generator including state estimates of inverters in the interconnected inverters, an observer gain matrix, residuals, and a coefficient matrix is ​​generated.

3. The method according to claim 1, characterized in that The method further comprises: According to the information layer communication and consistency theory, based on the hierarchical compensation control architecture and the interconnected inverter space model, the equivalent virtual impedance compensation control structure is distributedly optimized to generate a distributed optimized equivalent virtual impedance compensation control structure; Based on the distributed optimized equivalent virtual impedance compensation control structure, the equivalent virtual impedance compensation controller is solved to generate a distributed optimized equivalent virtual impedance compensation controller.

4. The method according to claim 3, characterized in that The method further comprises: Based on the distributed optimized equivalent virtual impedance compensation control structure, the output signal of the equivalent virtual impedance compensation controller is superimposed with the given signal of the voltage loop controller to generate a given signal; Based on the given signal shown, the virtual impedance is optimized according to the information of the reactive power of the interconnected inverters to achieve the equal distribution of the reactive power.

5. A virtual synchronous machine multi-machine interconnection hierarchical compensation control device, characterized in that: The device comprises: A residual generator design module, used to establish an interconnected inverter space model based on a preset interconnected inverter circuit, and generate a residual generator of an inverter in the interconnected inverter based on the interconnected inverter space model; A high-frequency disturbance compensation controller generation module is used to establish a hierarchical compensation control architecture, and based on the hierarchical compensation control architecture and the interconnected inverter space model, solve the high-frequency disturbance compensation controller based on the residual generator to generate a high-frequency disturbance compensation controller based on the residual generator; establish a hierarchical compensation control architecture based on the high-frequency disturbance compensation controller of the physical layer and the distributed optimized equivalent virtual impedance compensation controller of the information layer; design a high-frequency disturbance compensation controller at the physical layer to suppress high-frequency disturbances; design a distributed optimized equivalent virtual impedance compensation controller based on the information layer to achieve equal distribution of reactive power; An equivalent virtual impedance compensation controller generation module is used to perform distributed optimization on an equivalent virtual impedance compensation control structure based on a hierarchical compensation control architecture and the interconnected inverter space model, solve an equivalent virtual impedance compensation controller based on the distributed optimized equivalent virtual impedance compensation control structure, and generate a distributed optimized equivalent virtual impedance compensation controller; A multi-machine interconnected hierarchical compensation control module is used to establish a residual-based interconnected inverter hierarchical compensation control structure based on the residual generator-based high-frequency disturbance compensation controller and the distributed optimized equivalent virtual impedance compensation controller, and complete the multi-machine interconnected hierarchical compensation control of the virtual synchronous machine based on robust residual based on the residual-based interconnected inverter hierarchical compensation control structure.

Images