Cooperative control method and device for converter grid-connected system

Abstract

The invention provides a cooperative control method and device for a converter grid-connected system. The compensation power of the virtual synchronous generator is calculated according to the output voltage and the angular frequency of the converter, the voltage phase angle reference value of the virtual synchronous generator is determined according to the compensation power of the virtual synchronous generator, and cooperative control is carried out on the converter according to the voltage phase angle reference value of the virtual synchronous generator. According to the method, the absolute value of the real part of each pole of the converter grid-connected system can be increased through the compensation power of the virtual synchronous generator, so that the frequency response capability of the converter grid-connected system is improved, and the suppression of instantaneous violent oscillation of the frequency of the converter grid-connected system under the condition of load disturbance is realized; and the operation stability of the converter grid-connected system can be improved. According to the cooperative control method provided by the invention, the requirements on communication bandwidth and the like between different converters can be remarkably reduced, so that the converter grid-connected system can still operate efficiently under the condition that resources are limited.

Description

Technical Field

[0001] The present application relates to the field of renewable energy power generation technology, and in particular to a coordinated control method and device for a converter grid-connected system. Background Art

[0002] In order to provide inertia and damping support for high-penetration renewable energy grid-connected systems, virtual synchronous generators (VSG) are currently used to control converters. However, the introduction of virtual synchronous generator technology also brings about the inevitable rotor oscillation characteristics of traditional synchronous generators, which can easily lead to frequency oscillation of the converter grid-connected system when the load is disturbed, and power imbalance problems among converters, causing overcurrent or even damage to the converter.

[0003] If the damping coefficient, virtual inertia and other parameters of each converter are inconsistent, and the response speed of the converter is different, when the load increases or decreases, the converter with a faster response will output active power in advance, resulting in inconsistent output frequencies of different converters, which in turn causes instantaneous violent oscillations in the frequency of the converter grid-connected system. In other words, the stability of the converter grid-connected system is poor. Summary of the invention

[0004] In order to solve the problem of poor stability of the inverter grid-connected system in the prior art, the present application provides a coordinated control method of the inverter grid-connected system, which may include:

[0005] The compensation power of the virtual synchronous generator is calculated according to the output voltage and angular frequency of the converter.

[0006] A voltage phase angle reference value of the virtual synchronous generator is determined according to the compensation power of the virtual synchronous generator.

[0007] The converters are cooperatively controlled according to the voltage phase angle reference value of the virtual synchronous generator.

[0008] Optionally, the compensation power of the virtual synchronous generator satisfies:

[0009]

[0010] Among them, P comp represents the compensation power of the virtual synchronous generator, V i represents the output voltage of the i-th converter, V j represents the output voltage of the jth converter, B ij represents the line admittance between the i-th converter and the j-th converter, ω i represents the angular frequency of the i-th converter, ω jrepresents the angular frequency of the j-th converter, and Ω represents the set of converters adjacent to the i-th converter.

[0011] In some possible implementations, determining a voltage phase angle reference value of the virtual synchronous generator according to the compensation power of the virtual synchronous generator includes:

[0012] The electromagnetic power of the virtual synchronous generator is calculated according to the compensation power of the virtual synchronous generator, the active power command value of the converter and the actual value of the active power of the converter in combination with addition and subtraction operations.

[0013] The actual angular frequency of the converter is calculated according to the electromagnetic power of the virtual synchronous generator and the rated angular frequency of the converter in combination with an addition operation.

[0014] The actual angular frequency of the converter is integrated to obtain the voltage phase angle reference value of the virtual synchronous generator.

[0015] Exemplarily, the electromagnetic power of the virtual synchronous generator satisfies:

[0016]

[0017] Where P1 represents the electromagnetic power of the virtual synchronous generator, P ref Indicates the active power command value of the converter, P i represents the actual value of the active power of the i-th converter, ω0 represents the rated angular frequency of the converter, P comp Represents the compensation power of the virtual synchronous generator.

[0018] Optionally, the actual angular frequency of the inverter satisfies:

[0019]

[0020] Among them, ω i represents the actual angular frequency of the i-th converter, ω0 represents the rated angular frequency of the converter, P1 represents the electromagnetic power of the virtual synchronous generator, J represents the moment of inertia of the virtual synchronous generator, D represents the damping coefficient of the virtual synchronous generator, and s represents the integral operator.

[0021] In some other possible implementations, the converter is cooperatively controlled according to the voltage phase angle reference value of the virtual synchronous generator, including:

[0022] The difference between the reactive power reference value and the actual reactive power value of the converter is proportionally controlled to obtain the reference voltage of the converter.

[0023] The reference voltage of the converter is subjected to voltage and current double closed-loop control to obtain a d-axis reference voltage component and a q-axis reference voltage component of the converter.

[0024] According to the voltage phase angle reference value of the virtual synchronous generator, the d-axis reference voltage component and the q-axis reference voltage component of the converter are subjected to inverse Parker transformation to obtain the driving voltage.

[0025] The driving voltage is modulated to obtain a driving signal.

[0026] The inverter is controlled according to the driving signal.

[0027] In another aspect, the present application provides a coordinated control device for a converter grid-connected system, comprising:

[0028] The calculation module is used to calculate the compensation power of the virtual synchronous generator according to the output voltage and angular frequency of the converter.

[0029] The determination module is used to determine the voltage phase angle reference value of the virtual synchronous generator according to the compensation power of the virtual synchronous generator.

[0030] The control module is used to coordinately control the converter according to the voltage phase angle reference value of the virtual synchronous generator.

[0031] In a possible implementation, the calculation module specifically calculates the compensation power of the virtual synchronous generator according to the following formula:

[0032]

[0033] Among them, P comp represents the compensation power of the virtual synchronous generator, V i represents the output voltage of the i-th converter, V j represents the output voltage of the jth converter, B ij represents the line admittance between the i-th converter and the j-th converter, ω i represents the angular frequency of the i-th converter, ω j represents the angular frequency of the j-th converter, and Ω represents the set of converters adjacent to the i-th converter.

[0034] In another possible implementation, the determination module is specifically used for:

[0035] The electromagnetic power of the virtual synchronous generator is calculated according to the compensation power of the virtual synchronous generator, the active power command value of the converter and the actual value of the active power of the converter in combination with addition and subtraction operations.

[0036] The actual angular frequency of the converter is calculated according to the electromagnetic power of the virtual synchronous generator and the rated angular frequency of the converter in combination with an addition operation.

[0037] The actual angular frequency of the converter is integrated to obtain the voltage phase angle reference value of the virtual synchronous generator.

[0038] Exemplarily, the determination module specifically calculates the electromagnetic power of the virtual synchronous generator according to the following formula:

[0039]

[0040] Where P1 represents the electromagnetic power of the virtual synchronous generator, P ref Indicates the active power command value of the converter, P i represents the actual value of the active power of the i-th converter, ω0 represents the rated angular frequency of the converter, P comp Represents the compensation power of the virtual synchronous generator.

[0041] Optionally, the determination module calculates the actual angular frequency of the converter according to the following formula:

[0042]

[0043] Among them, ω i represents the actual angular frequency of the i-th converter, ω0 represents the rated angular frequency of the converter, P1 represents the electromagnetic power of the virtual synchronous generator, J represents the moment of inertia of the virtual synchronous generator, D represents the damping coefficient of the virtual synchronous generator, and s represents the integral operator.

[0044] In yet another possible implementation, the control module is specifically configured to:

[0045] The difference between the reactive power reference value and the actual reactive power value of the converter is proportionally controlled to obtain the reference voltage of the converter.

[0046] The reference voltage of the converter is subjected to voltage and current double closed-loop control to obtain a d-axis reference voltage component and a q-axis reference voltage component of the converter.

[0047] According to the voltage phase angle reference value of the virtual synchronous generator, the d-axis reference voltage component and the q-axis reference voltage component of the converter are subjected to inverse Parker transformation to obtain the driving voltage.

[0048] The driving voltage is modulated to obtain a driving signal.

[0049] The inverter is controlled according to the driving signal.

[0050] On the other hand, the present application also provides a computer device, including: one or more processors.

[0051] A processor is used to execute one or more programs.

[0052] When one or more programs are executed by one or more processors, the collaborative control method as described above is implemented.

[0053] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the above-mentioned collaborative control method is implemented.

[0054] Compared with the prior art, the beneficial effects of this application are:

[0055] In the collaborative control method provided by the present application, the compensation power of the virtual synchronous generator can be calculated according to the output voltage and angular frequency of the converter, the voltage phase angle reference value of the virtual synchronous generator can be determined according to the compensation power of the virtual synchronous generator, and the converter can be collaboratively controlled according to the voltage phase angle reference value of the virtual synchronous generator. The present application can increase the absolute value of the real part of each pole of the converter grid-connected system through the compensation power of the virtual synchronous generator, improve the frequency response capability of the converter grid-connected system, and suppress the instantaneous violent oscillation of the converter grid-connected system frequency under load disturbance, that is, it can improve the operating stability of the converter grid-connected system.

[0056] In the process of calculating the compensation power of the virtual synchronous generator, the present application takes into account each converter in the converter grid-connected system and the angular frequency of adjacent converters, thereby realizing dynamic cooperative control of the converter grid-connected system. It can be seen that the cooperative control method provided by the present application significantly reduces the requirements for communication bandwidth between different converters, so that the converter grid-connected system can still operate efficiently under resource-constrained conditions.

[0057] The collaborative control method provided in the present application can flexibly respond to the operating requirements of converter grid-connected systems under different scales and load conditions, and has high reliability and strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0059] Figure 1 A schematic structural diagram of a converter grid-connected system in an embodiment of the present application;

[0060] Figure 2 A schematic flow chart of a collaborative control method in an embodiment of the present application;

[0061] Figure 3 A schematic flow chart of determining a voltage phase angle reference value of a virtual synchronous generator in an embodiment of the present application;

[0062] Figure 4A schematic flow chart of cooperatively controlling a converter according to a voltage phase angle reference value of a virtual synchronous generator in an embodiment of the present application;

[0063] Figure 5 A schematic diagram of pole distribution of a converter grid-connected system in an embodiment of the present application;

[0064] Figure 6a It is a schematic diagram of the output power of each converter in the converter grid-connected system using virtual synchronous generator control;

[0065] Figure 6b A frequency diagram of each converter in a converter grid-connected system using virtual synchronous generator control;

[0066] Figure 7a A schematic diagram of the output power of each converter in a converter grid-connected system controlled by the coordinated control method provided in an embodiment of the present application;

[0067] Figure 7b A schematic diagram of the frequencies of each converter in a converter grid-connected system controlled by the coordinated control method provided in an embodiment of the present application;

[0068] Figure 8 It is a schematic structural diagram of the collaborative control device in an embodiment of the present application. DETAILED DESCRIPTION

[0069] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0070] The terms "first", "second", etc. in the specification embodiments, claims, and drawings of the present application are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. The method, system, product, or device is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0071] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0072] Embodiment 1:

[0073] The present application embodiment provides a method for coordinated control of a converter grid-connected system. Figure 1 As shown, the inverter grid-connected system 10 includes a wind power generation 1, a photovoltaic power generation 2, a battery energy storage 3, an inverter 4, an inverter 5 and an inverter 6. Figure 1 In, L f is the filter inductance of the converter, C f is the filter capacitor of the converter, Z line is the line impedance. PCC is the common connection point between wind power generation 1, photovoltaic power generation 2 and battery energy storage 3 and the main grid or load, Z g is the grid impedance, V g is the grid voltage, P l oad is the active power of the load.

[0074] like Figure 2 As shown, the collaborative control method 100 includes the following steps:

[0075] Step S1: Calculate the compensation power of the virtual synchronous generator according to the output voltage and angular frequency of the converter (which can be expressed as P comp express).

[0076] Step S2: Based on the compensation power P of the virtual synchronous generator comp Determine the voltage phase angle reference value (which can be represented by θ) of the virtual synchronous generator.

[0077] Step S3: performing coordinated control on the converter according to the voltage phase angle reference value θ of the virtual synchronous generator.

[0078] In some embodiments, the compensation power of the virtual synchronous generator in step S1 satisfies:

[0079]

[0080] Among them, P comp represents the compensation power of the virtual synchronous generator, V i represents the output voltage of the i-th converter, V j represents the output voltage of the jth converter, B ij represents the line admittance between the i-th converter and the j-th converter, ω i represents the angular frequency of the i-th converter, ω j represents the angular frequency of the j-th converter, and Ω represents the set of converters adjacent to the i-th converter.

[0081] In some other embodiments, in the above step S2, according to the compensation power P of the virtual synchronous generator comp Determine the voltage phase angle reference value θ of the virtual synchronous generator, including:

[0082] like Figure 3 As shown, according to the compensation power P of the virtual synchronous generator comp , the active power command value of the converter (can be expressed as P ref The electromagnetic power of the virtual synchronous generator (which can be represented by P1) is calculated by combining the addition and subtraction operations with the actual value of the active power of the converter.

[0083] Exemplarily, the electromagnetic power of the virtual synchronous generator satisfies:

[0084]

[0085] Where P1 represents the electromagnetic power of the virtual synchronous generator, P ref Indicates the active power command value of the converter, P i represents the actual value of the active power of the i-th converter, ω0 represents the rated angular frequency of the converter, P comp Represents the compensation power of the virtual synchronous generator.

[0086] The actual angular frequency of the converter is calculated based on the electromagnetic power P1 of the virtual synchronous generator and the rated angular frequency of the converter (which can be represented by ω0) and combined with addition operation.

[0087] Optionally, the actual angular frequency of the inverter satisfies:

[0088]

[0089] Among them, ω i represents the actual angular frequency of the i-th converter, ω0 represents the rated angular frequency of the converter, P1 represents the electromagnetic power of the virtual synchronous generator, J represents the moment of inertia of the virtual synchronous generator, D represents the damping coefficient of the virtual synchronous generator, and s represents the integral operator.

[0090] The actual angular frequency ω of the inverter i Integrate to obtain the voltage phase angle reference value θ of the virtual synchronous generator. Figure 3 In the equation, s represents the integral operator.

[0091] In some other embodiments, in step S3, the converter is cooperatively controlled according to the voltage phase angle reference value of the virtual synchronous generator, including:

[0092] like Figure 4 As shown, the reactive power reference value of the converter (which can be used with Q ref The difference between the actual value of reactive power (which can be represented by Q0) and the actual value of reactive power is proportionally controlled to obtain the reference voltage of the converter (which can be represented by V mref express).

[0093] The reference voltage V mref Perform voltage and current double closed-loop control to obtain the d-axis reference voltage component of the converter (which can be used with m d ) and the q-axis reference voltage component (which can be represented by m q express).

[0094] According to the voltage phase angle reference value of the virtual synchronous generator (which can be expressed as θ ref The d-axis reference voltage component m of the converter is d and the q-axis reference voltage component m q Perform an anti-Pike transformation to obtain the driving voltage (which can be used with V d express).

[0095] For driving voltage V d Modulation is performed to obtain a driving signal DS.

[0096] The inverter (such as the inverter 4) is controlled according to the driving signal DS.

[0097] In the embodiment of the present application, the inverter grid-connected system can be simulated in Matlab / Simulink to verify the control effect of the collaborative control method provided in the embodiment of the present application.

[0098] The simulation parameters of the inverter grid-connected system are shown in Table 1 below:

[0099] Table 1

[0100] parameter Inverter 4 Inverter 5 Inverter 6 <![CDATA[P ref / kW]]> 30 30 30 <![CDATA[f0 / Hz]]> 50 50 50 <![CDATA[K w ]]> 500 500 500 J 0.2 0.5 0.8 D 10 10 10 <![CDATA[X i / mΩ]]> 7.5 7.5 7.5

[0101] Table 1, P ref Indicates power command, f0 is rated frequency, K w is the active power-frequency droop coefficient, J is the virtual inertia coefficient, D is the damping coefficient, X i is the line impedance from the i-th converter to the common connection point.

[0102] The pole distribution diagram of the inverter grid-connected system is as follows: Figure 5 As shown, Figure 5 In the figure, the dotted poles are the pole distribution diagram of the virtual synchronous machine control strategy in the related art, and the solid poles are the system pole distribution diagram of the cooperative control method provided by the present application under the same parameter conditions. The arrow direction indicates the process of the damping coefficient a increasing from 0.01 to 0.1. Figure 5 It can be seen that the pole moves to the left as a whole, which proves that the damping ratio becomes larger and the damping characteristics are improved, achieving the effect of suppressing active oscillation.

[0103] Figure 6a and Figure 6b They are respectively schematic diagrams of output power and frequency of converter 4, converter 5 and converter 6 in a converter grid-connected system using virtual synchronous generator control. Figure 6a In FIG. 4 , the output power of converter 4 is denoted by P1, the output power of converter 5 is denoted by P2, and the output power of converter 6 is denoted by P3. Figure 6b In the figure, the frequency of converter 4 is represented by f1, the frequency of converter 5 is represented by f2, and the frequency of converter 6 is represented by f3. The active power of the load is set to 90kW. At t=1s, the active power of the load is disturbed and reduced by 30kW. It can be seen that after the active power of the load is disturbed, the output power and frequency of converter 4, converter 5 and converter 6 have large oscillations, the convergence time is about 1s, and the frequency change rate is large.

[0104] Figure 7a and Figure 7b They are respectively schematic diagrams of output power and frequency of converter 4, converter 5 and converter 6 in a converter grid-connected system controlled by the cooperative control method provided in an embodiment of the present application. Figure 7a In FIG. 4 , the output power of converter 4 is denoted by P1, the output power of converter 5 is denoted by P2, and the output power of converter 6 is denoted by P3. Figure 7b In the figure, the frequency of converter 4 is represented by f1, the frequency of converter 5 is represented by f2, and the frequency of converter 6 is represented by f3. It can be seen that after the active power disturbance of the load occurs at t=1s, compared with Figure 6a and Figure 6b , Figure 7a and Figure 7b The output power and frequency can complete a smooth transition in a short time, the overshoot of the output power and frequency is significantly reduced, the convergence time is about 0.5s faster, and the frequency change rate is significantly reduced. It can be seen that the collaborative control method provided in the embodiment of the present application has a significant inhibitory effect on oscillation, thereby verifying the effectiveness of the collaborative control method provided in the embodiment of the present application.

[0105] Embodiment 2:

[0106] Based on the same inventive concept, the embodiment of the present application also provides a coordinated control device for a converter grid-connected system. Figure 1 and above. Figure 8 As shown, the collaborative control device 200 includes:

[0107] The calculation module 21 is used to calculate the compensation power of the virtual synchronous generator according to the output voltage and angular frequency of the converter.

[0108] The determination module 22 is used to determine the voltage phase angle reference value of the virtual synchronous generator according to the compensation power of the virtual synchronous generator.

[0109] The control module 23 is used to coordinately control the converter according to the voltage phase angle reference value of the virtual synchronous generator.

[0110] In a possible implementation, the calculation module 21 specifically calculates the compensation power of the virtual synchronous generator according to the following formula:

[0111]

[0112] Among them, P comp represents the compensation power of the virtual synchronous generator, V i represents the output voltage of the i-th converter, V j represents the output voltage of the jth converter, B ij represents the line admittance between the i-th converter and the j-th converter, ω i represents the angular frequency of the i-th converter, ω j represents the angular frequency of the j-th converter, and Ω represents the set of converters adjacent to the i-th converter.

[0113] In another possible implementation, refer to Figure 3 , the determination module 22 is specifically used for:

[0114] The actual angular frequency of the converter is calculated based on the electromagnetic power P1 of the virtual synchronous generator and the rated angular frequency of the converter (which can be represented by ω0) and combined with addition operation.

[0115] Optionally, the actual angular frequency of the inverter satisfies:

[0116]

[0117] Among them, ω irepresents the actual angular frequency of the i-th converter, ω0 represents the rated angular frequency of the converter, P1 represents the electromagnetic power of the virtual synchronous generator, J represents the moment of inertia of the virtual synchronous generator, D represents the damping coefficient of the virtual synchronous generator, and s represents the integral operator.

[0118] The actual angular frequency ω of the inverter i Integrate to obtain the voltage phase angle reference value θ of the virtual synchronous generator.

[0119] Exemplarily, the determination module 22 specifically calculates the electromagnetic power of the virtual synchronous generator according to the following formula:

[0120]

[0121] Where P1 represents the electromagnetic power of the virtual synchronous generator, P ref Indicates the active power command value of the converter, P i represents the actual value of the active power of the i-th converter, ω0 represents the rated angular frequency of the converter, P comp Represents the compensation power of the virtual synchronous generator.

[0122] Optionally, the determination module 22 specifically calculates the actual angular frequency of the converter according to the following formula:

[0123]

[0124] Among them, ω i represents the actual angular frequency of the i-th converter, ω0 represents the rated angular frequency of the converter, P1 represents the electromagnetic power of the virtual synchronous generator, J represents the moment of inertia of the virtual synchronous generator, and D represents the damping coefficient of the virtual synchronous generator.

[0125] In yet another possible implementation, the control module 23 is specifically configured to:

[0126] refer to Figure 4 , the reactive power reference value of the converter (which can be used with Q ref The difference between the actual value of reactive power (which can be represented by Q0) and the actual value of reactive power is proportionally controlled to obtain the reference voltage of the converter (which can be represented by V mref express).

[0127] The reference voltage V mref Perform voltage and current double closed-loop control to obtain the d-axis reference voltage component of the converter (which can be used with m d ) and the q-axis reference voltage component (which can be represented by m d express).

[0128] According to the voltage phase angle reference value of the virtual synchronous generator (which can be refThe d-axis reference voltage component m of the converter is d and the q-axis reference voltage component m d Perform an anti-Pike transformation to obtain the driving voltage (which can be used with V d express).

[0129] For driving voltage V d Modulation is performed to obtain a driving signal DS.

[0130] The inverter (such as the inverter 4) is controlled according to the driving signal DS.

[0131] Embodiment 3:

[0132] Based on the same inventive concept, an embodiment of the present application also provides a computer device, which includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in a computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the collaborative control method provided in the above embodiment.

[0133] Embodiment 4:

[0134] Based on the same inventive concept, the embodiment of the present application also provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here may include a built-in storage medium in a computer device, and of course may also include an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions may be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here may be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor may load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the collaborative control method provided in the above embodiment.

[0135] Those skilled in the art will appreciate that the embodiments of the application may be provided as methods, systems, or computer program products. Therefore, the application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0136] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0137] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0138] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0139] The above are merely embodiments of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the pending application.

Claims

1. A coordinated control method for a converter grid-connected system, characterized in that: include: Calculating the compensation power of the virtual synchronous generator according to the output voltage and angular frequency of the converter; Determine a voltage phase angle reference value of the virtual synchronous generator according to the compensation power of the virtual synchronous generator; The converter is cooperatively controlled according to the voltage phase angle reference value of the virtual synchronous generator.

2. The collaborative control method according to claim 1, characterized in that: The compensation power of the virtual synchronous generator satisfies: Among them, P comp represents the compensation power of the virtual synchronous generator, V i represents the output voltage of the i-th converter, V j represents the output voltage of the jth converter, B ij represents the line admittance between the i-th converter and the j-th converter, ω i represents the angular frequency of the i-th converter, ω j represents the angular frequency of the j-th converter, and Ω represents the set of converters adjacent to the i-th converter.

3. The collaborative control method according to claim 1, characterized in that: The step of determining the voltage phase angle reference value of the virtual synchronous generator according to the compensation power of the virtual synchronous generator comprises: Calculating the electromagnetic power of the virtual synchronous generator according to the compensation power of the virtual synchronous generator, the active power command value of the converter and the actual value of the active power of the converter in combination with addition and subtraction operations; Calculating the actual angular frequency of the converter according to the electromagnetic power of the virtual synchronous generator and the rated angular frequency of the converter in combination with an addition operation; The actual angular frequency of the converter is integrated to obtain a voltage phase angle reference value of the virtual synchronous generator.

4. The collaborative control method according to claim 3, characterized in that: The electromagnetic power of the virtual synchronous generator satisfies: Wherein, P1 represents the electromagnetic power of the virtual synchronous generator, P ref represents the active power command value of the converter, P i represents the actual value of the active power of the i-th converter, ω0 represents the rated angular frequency of the converter, P comp represents the compensation power of the virtual synchronous generator.

5. The collaborative control method according to claim 3, characterized in that: The actual angular frequency of the converter satisfies: Among them, ω i represents the actual angular frequency of the i-th converter, ω0 represents the rated angular frequency of the converter, P1 represents the electromagnetic power of the virtual synchronous generator, J represents the moment of inertia of the virtual synchronous generator, D represents the damping coefficient of the virtual synchronous generator, and s represents the integral operator.

6. The collaborative control method according to claim 1, characterized in that: The method of cooperatively controlling the converter according to the voltage phase angle reference value of the virtual synchronous generator comprises: Proportional control is performed on the difference between the reactive power reference value and the actual reactive power value of the converter to obtain a reference voltage of the converter; Performing voltage-current dual closed-loop control on the reference voltage of the converter to obtain a d-axis reference voltage component and a q-axis reference voltage component of the converter; According to the voltage phase angle reference value of the virtual synchronous generator, an inverse Park transformation is performed on the d-axis reference voltage component and the q-axis reference voltage component of the converter to obtain a driving voltage; Modulating the driving voltage to obtain a driving signal; The inverter is controlled according to the driving signal.

7. A coordinated control device for a converter grid-connected system, characterized in that: include: A calculation module, used for calculating the compensation power of the virtual synchronous generator according to the output voltage and angular frequency of the converter; A determination module, configured to determine a voltage phase angle reference value of the virtual synchronous generator according to the compensation power of the virtual synchronous generator; A control module is used to coordinately control the converter according to the voltage phase angle reference value of the virtual synchronous generator.

8. The cooperative control device according to claim 7, characterized in that: The calculation module specifically calculates the compensation power of the virtual synchronous generator according to the following formula: Among them, P comp represents the compensation power of the virtual synchronous generator, V i represents the output voltage of the i-th converter, V j represents the output voltage of the jth converter, B ij represents the line admittance between the i-th converter and the j-th converter, ω i represents the angular frequency of the i-th converter, ω j represents the angular frequency of the j-th converter, and Ω represents the set of converters adjacent to the i-th converter.

9. The cooperative control device according to claim 7, characterized in that: The determination module is specifically used for: Calculating the electromagnetic power of the virtual synchronous generator according to the compensation power of the virtual synchronous generator, the active power command value of the converter and the actual value of the active power of the converter in combination with addition and subtraction operations; Calculating the actual angular frequency of the converter according to the electromagnetic power of the virtual synchronous generator and the rated angular frequency of the converter in combination with an addition operation; The actual angular frequency of the converter is integrated to obtain a voltage phase angle reference value of the virtual synchronous generator.

10. The cooperative control device according to claim 8, characterized in that: The determination module specifically calculates the electromagnetic power of the virtual synchronous generator according to the following formula: Wherein, P1 represents the electromagnetic power of the virtual synchronous generator, P ref represents the active power command value of the converter, P i represents the actual value of the active power of the i-th converter, ω0 represents the rated angular frequency of the converter, P comp represents the compensation power of the virtual synchronous generator.

11. The cooperative control device according to claim 8, characterized in that: The determination module specifically calculates the actual angular frequency of the converter according to the following formula: Among them, ω i represents the actual angular frequency of the i-th converter, ω0 represents the rated angular frequency of the converter, P1 represents the electromagnetic power of the virtual synchronous generator, J represents the moment of inertia of the virtual synchronous generator, D represents the damping coefficient of the virtual synchronous generator, and s represents the integral operator.

12. The cooperative control device according to claim 7, characterized in that: The control module is specifically used for: Proportional control is performed on the difference between the reactive power reference value and the actual reactive power value of the converter to obtain a reference voltage of the converter; Performing voltage-current dual closed-loop control on the reference voltage of the converter to obtain a d-axis reference voltage component and a q-axis reference voltage component of the converter; According to the voltage phase angle reference value of the virtual synchronous generator, an inverse Park transformation is performed on the d-axis reference voltage component and the q-axis reference voltage component of the converter to obtain a driving voltage; Modulating the driving voltage to obtain a driving signal; The inverter is controlled according to the driving signal.

13. A computer device, characterized in that: include: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the collaborative control method according to any one of claims 1 to 6 is implemented.

14. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the collaborative control method as described in any one of claims 1 to 6 is implemented.

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