Method and device for setting proportional-integral coefficient of network-forming converter

Abstract

The invention provides a method and a device for setting a proportional-integral coefficient of a network-forming converter, and the method comprises the steps: setting a first proportional coefficient and a first integral coefficient of a voltage loop according to a current reference value outputted by the voltage loop; and setting the second proportionality coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value output by the current loop. The proportional-integral coefficient obtained by the method has universality, the proportional-integral coefficient capable of stably and reliably operating can be provided for the network-forming converter, and the setting efficiency is improved. According to the invention, the network-forming type current converter and the filter inductor are equivalent to the current source, the voltage differential equation of the filter capacitor is constructed, and the current reference value output by the voltage loop is obtained. In addition, a network-forming type converter is equivalent to a voltage source, a current differential equation of a filter inductor is constructed, a modulation voltage reference value output by a current loop is obtained, and a reliable basis is provided for setting of a proportional-integral coefficient.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a method and device for adjusting the proportional-integral coefficient of a grid-type converter. Background Art

[0002] A grid-type converter can be equivalent to a voltage source, providing a stable output voltage within a certain range. Instead of relying on the grid connection point voltage to adjust output power, the grid-type converter directly establishes the grid connection point voltage, allowing the grid-type converter to maintain independent operation even when disconnected from the AC grid.

[0003] Typically, a voltage-current dual-loop control method in a two-phase rotating coordinate system can be used to control a grid-type converter. In other words, a voltage-loop and current-loop combined control method can be used to control a grid-type converter.

[0004] Related technologies typically perform multiple debugging and optimization of pre-set proportional-integral coefficients to obtain the proportional and integral coefficients (hereinafter referred to as proportional-integral coefficients) for the voltage and current loops, respectively. However, the proportional-integral coefficients obtained through multiple debugging and optimization processes are not universal, and it is difficult to obtain proportional-integral coefficients that can ensure stable and reliable operation of the grid-type converter in a short period of time. In other words, debugging the proportional-integral coefficients takes a lot of time, resulting in low proportional-integral coefficient setting efficiency. Summary of the Invention

[0005] In order to solve the problem of low modulation efficiency of proportional-integral coefficient in the prior art, the present application provides a method and device for adjusting the proportional-integral coefficient of a grid-type converter.

[0006] In a first aspect, the present application provides a method for adjusting the proportional-integral coefficient of a grid-type converter, which may include:

[0007] The voltage differential equation of the filter capacitor is differentiated to obtain a current reference value for the voltage loop output. The current differential equation of the filter inductor is constructed based on the current reference value, and this current differential equation is differentiated to obtain a modulation voltage reference value for the current loop output. The first proportional coefficient and first integral coefficient of the voltage loop are adjusted based on the current reference value, and the second proportional coefficient and second integral coefficient of the current loop are adjusted based on the modulation voltage reference value.

[0008] For example, the voltage differential equation satisfies:

[0009]

[0010] Among them, u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor. Indicates the rate of change of the actual value of the d-axis voltage of the filter capacitor, Indicates the rate of change of the actual value of the q-axis voltage of the filter capacitor. ω indicates the power frequency angular velocity of the AC power grid. C indicates the capacitance of the filter capacitor. d_ref Indicates the d-axis current reference value of the filter inductor, i q_ref Indicates the q-axis current reference value of the filter inductor. d_out Indicates the actual value of the d-axis current flowing into the AC grid at the grid connection point, i q_out Indicates the actual value of the q-axis current flowing into the AC grid at the grid connection point.

[0011] Optionally, the current reference value satisfies:

[0012]

[0013] Among them, T represents the control period, u d_ref Indicates the d-axis voltage reference value of the filter inductor, u q_ref Indicates the q-axis voltage reference value of the filter inductor.

[0014] In some possible implementations, adjusting the first proportional coefficient and the first integral coefficient of the voltage loop according to the current reference value includes:

[0015] According to the current reference value, the first proportional coefficient is adjusted to Set the first integral coefficient to 0.

[0016] For example, the current differential equation satisfies:

[0017]

[0018] Among them, i d Indicates the actual value of the d-axis current of the filter inductor, i q Indicates the actual value of the q-axis current of the filter inductor. Indicates the rate of change of the actual value of the d-axis current of the filter inductor, Indicates the rate of change of the actual value of the q-axis current of the filter inductor. ω indicates the power frequency angular velocity of the AC power grid. L indicates the inductance of the filter inductor. u d-m Indicates the d-axis modulation voltage reference value of the current loop output, u q-m Indicates the q-axis modulation voltage reference value of the current loop output. d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor.

[0019] Optionally, the modulation voltage reference value satisfies:

[0020]

[0021] Where T represents the control period. k represents the high-frequency suppression constant, satisfying k ≥ 1.

[0022] In some other possible implementations, adjusting the second proportional coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value includes:

[0023] According to the modulation voltage reference value, the second proportional coefficient is adjusted to Set the second integral coefficient to 0.

[0024] In a second aspect, the present application provides a device for adjusting the proportional-integral coefficient of a grid-type converter, which may include:

[0025] The first processing module is used to perform difference processing on the voltage differential equation of the filter capacitor to obtain a current reference value output by the voltage loop.

[0026] The second processing module is used to perform difference processing on the current differential equation according to the current reference value to obtain a modulation voltage reference value output by the current loop.

[0027] The adjustment module is used to adjust the first proportional coefficient and the first integral coefficient of the voltage loop according to the current reference value, and to adjust the second proportional coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value.

[0028] In some possible implementations, the first processing module determines the voltage differential equation according to the following formula:

[0029]

[0030] Among them, u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor. Indicates the rate of change of the actual value of the d-axis voltage of the filter capacitor, Indicates the rate of change of the actual value of the q-axis voltage of the filter capacitor. ω indicates the power frequency angular velocity of the AC power grid. C indicates the capacitance of the filter capacitor. d_ref Indicates the d-axis current reference value of the filter inductor, i q_ref Indicates the q-axis current reference value of the filter inductor. d_out Indicates the actual value of the d-axis current flowing into the AC grid at the grid connection point, i q_out Indicates the actual value of the q-axis current flowing into the AC grid at the grid connection point.

[0031] Optionally, the current reference value satisfies:

[0032]

[0033] Among them, T represents the control period, ud_ref Indicates the d-axis voltage reference value of the filter inductor, u q_ref Indicates the q-axis voltage reference value of the filter inductor.

[0034] In some other possible implementations, the tuning module is specifically configured to:

[0035] According to the current reference value, the first proportional coefficient is adjusted to Set the first integral coefficient to 0.

[0036] Exemplarily, the second processing module determines the current differential equation according to the following formula:

[0037]

[0038] Among them, i d Indicates the actual value of the d-axis current of the filter inductor, i q Indicates the actual value of the q-axis current of the filter inductor. Indicates the rate of change of the actual value of the d-axis current of the filter inductor, Indicates the rate of change of the actual value of the q-axis current of the filter inductor. ω indicates the power frequency angular velocity of the AC power grid. L indicates the inductance of the filter inductor. u d-m Indicates the d-axis modulation voltage reference value of the current loop output, u q-m Indicates the q-axis modulation voltage reference value of the current loop output. d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor.

[0039] Optionally, the modulation voltage reference value satisfies:

[0040]

[0041] Where T represents the control period. k represents the high-frequency suppression constant, satisfying k ≥ 1.

[0042] In some further possible implementations, the tuning module is specifically configured to:

[0043] According to the modulation voltage reference value, the second proportional coefficient is adjusted to Set the second integral coefficient to 0.

[0044] On the other hand, the present application also provides a computer device, including: one or more processors.

[0045] A processor is used to execute one or more programs.

[0046] When one or more programs are executed by one or more processors, the tuning method described above is implemented.

[0047] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the above-mentioned tuning method.

[0048] Compared with the prior art, the present invention has the following advantages:

[0049] In the tuning method provided in this application, the first proportional coefficient and first integral coefficient of the voltage loop are tuned based on the current reference value output by the voltage loop, and the second proportional coefficient and second integral coefficient of the current loop are tuned based on the modulation voltage reference value output by the current loop. Compared to the proportional-integral coefficients obtained through debugging and optimization in related technologies, the proportional-integral coefficients obtained in this application are universal and can provide stable and reliable proportional-integral coefficients for grid-type converters, improving tuning efficiency.

[0050] This application constructs the voltage differential equation of the filter capacitor by treating the grid-type converter and the filter inductor as equivalent current sources, and obtains the current reference value of the voltage loop output based on the voltage differential equation, providing a reliable basis for the adjustment of the proportional integral coefficient.

[0051] This application also constructs the current differential equation of the filter inductor by treating the grid-type converter as an equivalent voltage source, and obtains the modulation voltage reference value of the current loop output based on the current differential equation of the filter inductor, further providing a reliable basis for the adjustment of the proportional integral coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative labor.

[0053] Figure 1 This is an equivalent circuit diagram of a grid-type converter connected to an AC power grid in an embodiment of the present application;

[0054] Figure 2 A schematic flow chart of the setting method in the embodiment of the present application;

[0055] Figure 3 This is a structural diagram of the grid-type converter and the filter inductor being equivalent to a current source in an embodiment of the present application;

[0056] Figure 4 A schematic diagram of a voltage loop in an embodiment of the present application;

[0057] Figure 5 This is a structural diagram of a grid-type converter in an embodiment of the present application that is equivalent to a voltage source;

[0058] Figure 6 A schematic diagram of a current loop in an embodiment of the present application;

[0059] Figure 7 This is a schematic topological diagram of a large disturbance test in an embodiment of the present application;

[0060] Figure 8a This is a waveform diagram of the active power on the grid side of the transformer in the embodiment of the present application;

[0061] Figure 8b This is a waveform diagram of the effective value of the transformer grid-side line voltage in the embodiment of the present application;

[0062] Figure 8c This is a waveform diagram of the voltage on the grid side phase A of the transformer in the embodiment of the present application;

[0063] Figure 8d This is a waveform diagram of the A-phase current on the grid side of the transformer in the embodiment of the present application;

[0064] Figure 9 This is a schematic structural diagram of the setting device in an embodiment of the present application. DETAILED DESCRIPTION

[0065] The technical solution in this application will be described below with reference to the accompanying drawings.

[0066] The terms "first," "second," and the like in the description, embodiments, claims, and drawings of this application are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions, such as, for example, inclusion of a series of steps or units. A method, system, product, or apparatus is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0067] It should be understood that in this 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 previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items 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.

[0068] Example 1:

[0069] The present invention provides a method for adjusting the proportional-integral coefficient of a meshed converter. For a meshed converter, a voltage-current dual-loop control method can be used in a two-phase rotating coordinate system to achieve control of the meshed converter. In other words, a combined voltage and current loop control method can be used to control the meshed converter.

[0070] Optionally, the grid-type converter 1 can be connected to the AC grid S via the filter 2. The equivalent circuit is as follows: Figure 1 The filter 2 may include a filter inductor L and a filter capacitor C.

[0071] like Figure 2 As shown, the tuning method 100 includes the following steps:

[0072] Step S1: performing differentiation processing on the voltage differential equation of the filter capacitor to obtain a current reference value output by the voltage loop.

[0073] Step S2: performing differentiation processing on the current differential equation according to the current reference value to obtain a modulation voltage reference value output by the current loop.

[0074] Step S3: adjusting the first proportional coefficient and the first integral coefficient of the voltage loop according to the current reference value, and adjusting the second proportional coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value.

[0075] Optionally, you can Figure 1 The grid-type converter 1 and the filter inductor L are equivalent to a current source I. Figure 1 It can be simplified as Figure 3 The equivalent circuit shown in Figure 1 is as follows. Therefore, in the αβ coordinate system (i.e., the two-phase stationary coordinate system), the voltage differential equation of the filter capacitor can satisfy:

[0076]

[0077] Among them, u α Indicates the actual value of the voltage at the α-axis end of the filter capacitor, Indicates the rate of change of the actual value of the voltage at the α-axis end of the filter capacitor, i α_ref Indicates the α-axis current reference value of the filter inductor, i α_out Indicates the actual value of the α-axis current flowing into the AC grid at the grid connection point. C indicates the capacitance of the filter capacitor. u β Indicates the actual value of the voltage at the β-axis end of the filter capacitor, Indicates the rate of change of the actual value of the voltage at the β-axis end of the filter capacitor, i β_ref Indicates the β-axis current reference value of the filter inductor, i β_out Indicates the actual value of the β-axis current flowing into the AC grid at the grid connection point.

[0078] will u α and u β Perform Park transformation to obtain the voltage differential equation. That is, the voltage differential equation satisfies:

[0079]

[0080] Among them, u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor. Indicates the rate of change of the actual value of the d-axis voltage of the filter capacitor, Indicates the rate of change of the actual value of the q-axis voltage of the filter capacitor. ω indicates the power frequency angular velocity of the AC power grid. C indicates the capacitance of the filter capacitor. d_ref Indicates the d-axis current reference value of the filter inductor, i q_ref Indicates the q-axis current reference value of the filter inductor. d_out Indicates the actual value of the d-axis current flowing into the AC grid at the grid connection point, i q_out Indicates the actual value of the q-axis current flowing into the AC grid at the grid connection point.

[0081] because The current reference value can meet:

[0082]

[0083] Among them, T represents the control period, u d_ref Indicates the d-axis voltage reference value of the filter inductor, u q_ref Indicates the q-axis voltage reference value of the filter inductor.

[0084] In some possible implementations, adjusting the first proportional coefficient and the first integral coefficient of the voltage loop according to the current reference value includes:

[0085] According to the current reference value, the Figure 4 The first proportional coefficient K of the medium voltage loop p1 Set to The first integral coefficient K i1 Set to 0. That satisfies K i1 =0.

[0086] In some embodiments, Figure 1 The grid-type converter 1 is equivalent to a voltage source U. Figure 1 It can be simplified as Figure 5 The equivalent circuit shown in Figure 1 is as follows. Therefore, in the αβ coordinate system (i.e., the two-phase stationary coordinate system), the current differential equation of the filter inductor can be satisfied:

[0087]

[0088] Among them, i α Indicates the actual value of the α-axis current of the filter inductor, u α-m Indicates the α-axis modulation voltage reference value of the current loop output, u α Indicates the actual value of the α-axis voltage of the filter capacitor. β Indicates the actual value of the β-axis current of the filter inductor, u β-m Indicates the β-axis modulation voltage reference value of the current loop output, u β Indicates the actual value of the β-axis voltage of the filter capacitor.

[0089] will i α and i β Performing Park transformation (i.e. Park transformation) yields the current differential equation. That is, the current differential equation satisfies:

[0090]

[0091] Among them, i d Indicates the actual value of the d-axis current of the filter inductor, i q Indicates the actual value of the q-axis current of the filter inductor. Indicates the rate of change of the actual value of the d-axis current of the filter inductor, Indicates the rate of change of the actual value of the q-axis current of the filter inductor. ω indicates the power frequency angular velocity of the AC power grid. L indicates the inductance of the filter inductor. u d-m Indicates the d-axis modulation voltage reference value of the current loop output, u q-m Indicates the q-axis modulation voltage reference value of the current loop output. d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor.

[0092] Therefore, the modulation voltage reference value satisfies:

[0093]

[0094] Where T represents the control period. k represents the high-frequency suppression constant, satisfying k ≥ 1.

[0095] In some other possible implementations, adjusting the second proportional coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value includes:

[0096] According to the modulation voltage reference value, Figure 6 The second proportional coefficient of the current loop is K p2 Determined The second integral coefficient K i2 Set to 0. That satisfies K i2 =0.

[0097] It can be understood that when k is an integer greater than or equal to 2, the sensitivity of the current loop can be reduced to prevent the oscillation from being amplified, that is, it can play a role in suppressing disturbances and noise.

[0098] The embodiment of the present application can use electromagnetic transient simulation software to model the current loop and voltage loop, and perform large disturbance tests such as black start and switch switching on the grid-type converter. Figure 7 As shown, the test topology may include a grid-type converter 1 (which may be 3MW), a filter 2, a transformer 3 (which may be 690V / 35kV), and a switch BRK. The grid-type converter 1 may be connected to a 35kV AC grid S through the filter 2, transformer 3, and switch BRK. The test process includes:

[0099] Black start: The switch BRK remains in the off state, the grid-type converter is started, and a 690V AC voltage is established. The time when a stable voltage is established is selected as time 0.

[0100] N-1 operating condition: At 0.4s, the switch BRK is closed and the power reference value of the grid-type converter is zero.

[0101] Power step: Adjust the power reference value of the grid-type converter to the rated power (which can be 3MW).

[0102] Through simulation, we can get Figure 8a The active power waveform of transformer 3 on the grid side is shown in the figure. Figure 8b The waveform of the effective value of the line voltage on the grid side of transformer 3 is shown in the figure. Figure 8c The voltage waveform of phase A (similar to phase B and phase C) on the grid side of the transformer is shown as well as Figure 8d The current waveform of phase A (similar to phase B and phase C) on the grid side of transformer 3 is shown. Figures 8a to 8d In the figure, the horizontal axis represents time t, and the unit can be seconds (s). Figure 8a The middle vertical axis represents the active power P on the grid side of transformer 3. Figure 8b The middle vertical axis represents the effective value of the transformer 3 grid side line voltage U rms , Figure 8c The middle vertical axis represents the A phase voltage U on the grid side of transformer 3 A , Figure 8d The middle vertical axis represents the transformer 3 grid side A phase current I A .

[0103] The measuring points on the grid side of the transformer are Figure 7 During the black start process, a stable 690V AC voltage was established. After closing the switch, the active power quickly recovered to the reference value of 0MW, and the entire topology quickly regained stability. After increasing the power reference value to 3MW, the active power quickly tracked to the reference value of 3MW, and the voltage and current quickly regained stability. It can be seen that the parameter setting method provided in this application has strong stability and robustness.

[0104] Example 2:

[0105] Based on the same inventive concept, the embodiment of the present application also provides a device for adjusting the proportional integral coefficient of a grid-type converter. Figure 9 As shown, the setting device 200 may include:

[0106] The first processing module 201 is configured to perform a difference process on the voltage differential equation of the filter capacitor to obtain a current reference value output by the voltage loop.

[0107] The second processing module 202 is configured to perform a difference process on the current differential equation according to the current reference value to obtain a modulation voltage reference value output by the current loop.

[0108] The adjustment module 203 is used to adjust the first proportional coefficient and the first integral coefficient of the voltage loop according to the current reference value, and to adjust the second proportional coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value.

[0109] In some possible implementations, the first processing module 201 determines the voltage differential equation according to the following formula:

[0110]

[0111] Among them, u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor. Indicates the rate of change of the actual value of the d-axis voltage of the filter capacitor, Indicates the rate of change of the actual value of the q-axis voltage of the filter capacitor. ω indicates the power frequency angular velocity of the AC power grid. C indicates the capacitance of the filter capacitor. d_ref Indicates the d-axis current reference value of the filter inductor, i q_ref Indicates the q-axis current reference value of the filter inductor. d_out Indicates the actual value of the d-axis current flowing into the AC grid at the grid connection point, i q_out Indicates the actual value of the q-axis current flowing into the AC grid at the grid connection point.

[0112] Optionally, the current reference value satisfies:

[0113]

[0114] Wherein, T represents the control period.

[0115] In some other possible implementations, the setting module 203 is specifically configured to:

[0116] According to the current reference value, the first proportional coefficient is adjusted to Set the first integral coefficient to 0.

[0117] Exemplarily, the second processing module 202 determines the current differential equation according to the following formula:

[0118]

[0119] Among them, i d Indicates the actual value of the d-axis current of the filter inductor, i q Indicates the actual value of the q-axis current of the filter inductor. Indicates the rate of change of the actual value of the d-axis current of the filter inductor, Indicates the rate of change of the actual value of the q-axis current of the filter inductor. ω indicates the power frequency angular velocity of the AC power grid. L indicates the inductance of the filter inductor. u d-m Indicates the d-axis modulation voltage reference value of the current loop output, u q-m Indicates the q-axis modulation voltage reference value of the current loop output. d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor.

[0120] Optionally, the modulation voltage reference value satisfies:

[0121]

[0122] Where T represents the control period. k represents the high-frequency suppression constant, satisfying k ≥ 1.

[0123] In some further possible implementations, the tuning module is specifically configured to:

[0124] According to the modulation voltage reference value, the second proportional coefficient is adjusted to Set the second integral coefficient to 0.

[0125] Example 3:

[0126] Based on the same inventive concept, an embodiment of the present application further provides a computer device, which includes a processor and a memory, the memory being used to store a computer program, the computer program including program instructions, and the processor being used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may be 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 is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of the setting method provided in the above embodiment.

[0127] Example 4:

[0128] Based on the same inventive concept, an embodiment of the present application also provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the tuning method provided in the above embodiment.

[0129] Those skilled in the art will appreciate that embodiments of the application may be provided as methods, systems, or computer program products. Thus, the application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, 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 magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0130] 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 a 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 produce 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.

[0131] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work 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 1 The function specified in one or more boxes.

[0132] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0133] 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 method for adjusting the proportional-integral coefficient of a grid-type converter, characterized in that: include: Perform difference processing on the voltage differential equation of the filter capacitor to obtain the current reference value output by the voltage loop; Performing a difference process on the current differential equation according to the current reference value to obtain a modulation voltage reference value output by the current loop; The first proportional coefficient and the first integral coefficient of the voltage loop are adjusted according to the current reference value, and the second proportional coefficient and the second integral coefficient of the current loop are adjusted according to the modulation voltage reference value.

2. The setting method according to claim 1, characterized in that: The voltage differential equation satisfies: Among them, u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor; represents the rate of change of the actual value of the d-axis voltage of the filter capacitor, represents the rate of change of the actual value of the q-axis voltage of the filter capacitor; ω represents the power frequency angular velocity of the AC power grid; C represents the capacitance of the filter capacitor; i d_ref represents the d-axis current reference value of the filter inductor, i q_ref represents the q-axis current reference value of the filter inductor; i d_out represents the actual value of the d-axis current flowing into the AC grid from the grid connection point, i q_out Indicates the actual value of the q-axis current flowing into the AC power grid from the grid connection point.

3. The setting method according to claim 2, characterized in that: The current reference value satisfies: Among them, T represents the control period, u d_ref Indicates the d-axis voltage reference value of the filter inductor, u q_ref represents the q-axis voltage reference value of the filter inductor.

4. The setting method according to claim 3, characterized in that: The adjusting the first proportional coefficient and the first integral coefficient of the voltage loop according to the current reference value includes: According to the current reference value, the first proportional coefficient is set to The first integral coefficient is set to 0.

5. The setting method according to claim 1, characterized in that: The current differential equation satisfies: Among them, i d Indicates the actual value of the d-axis current of the filter inductor, i q represents the actual value of the q-axis current of the filter inductor; represents the rate of change of the actual value of the d-axis current of the filter inductor, represents the rate of change of the actual value of the q-axis current of the filter inductor; ω represents the power frequency angular velocity of the AC power grid; L represents the inductance value of the filter inductor; u d-m Indicates the d-axis modulation voltage reference value output by the current loop, u q-m represents the q-axis modulation voltage reference value output by the current loop; u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor.

6. The setting method according to claim 5, characterized in that: The modulation voltage reference value satisfies: Where T represents the control period; k represents the high-frequency suppression constant, satisfying k≥1; i d_ref represents the d-axis current reference value of the filter inductor, i q_ref represents the q-axis current reference value of the filter inductor.

7. The setting method according to claim 6, characterized in that: The adjusting the second proportional coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value includes: According to the modulation voltage reference value, the second proportional coefficient is set to The second integral coefficient is set to 0.

8. A device for adjusting the proportional-integral coefficient of a grid-type converter, characterized in that: include: The first processing module is used to perform difference processing on the voltage differential equation of the filter capacitor to obtain a current reference value output by the voltage loop; A second processing module is used to perform difference processing on the current differential equation according to the current reference value to obtain a modulation voltage reference value output by the current loop; A setting module is used to set the first proportional coefficient and the first integral coefficient of the voltage loop according to the current reference value, and to set the second proportional coefficient and the second integral coefficient of the current loop according to the modulation voltage reference value.

9. The setting device according to claim 8, characterized in that: The first processing module determines the voltage differential equation according to the following formula: Among them, u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor; represents the rate of change of the actual value of the d-axis voltage of the filter capacitor, represents the rate of change of the actual value of the q-axis voltage of the filter capacitor; ω represents the power frequency angular velocity of the AC power grid; C represents the capacitance of the filter capacitor; i d_ref represents the d-axis current reference value of the filter inductor, i q_ref represents the q-axis current reference value of the filter inductor; i d_out represents the actual value of the d-axis current flowing into the AC grid from the grid connection point, i q_out Indicates the actual value of the q-axis current flowing into the AC power grid from the grid connection point.

10. The setting device according to claim 9, characterized in that: The current reference value satisfies: Among them, T represents the control period, u d_ref Indicates the d-axis voltage reference value of the filter inductor, u q_ref represents the q-axis voltage reference value of the filter inductor.

11. The setting device according to claim 10, characterized in that: The setting module is specifically used for: According to the current reference value, the first proportional coefficient is set to The first integral coefficient is set to 0.

12. The setting device according to claim 8, characterized in that The second processing module determines the current differential equation according to the following formula: Among them, i d Indicates the actual value of the d-axis current of the filter inductor, i q represents the actual value of the q-axis current of the filter inductor; represents the rate of change of the actual value of the d-axis current of the filter inductor, represents the rate of change of the actual value of the q-axis current of the filter inductor; ω represents the power frequency angular velocity of the AC power grid; L represents the inductance value of the filter inductor; u d-m Indicates the d-axis modulation voltage reference value output by the current loop, u q-m represents the q-axis modulation voltage reference value output by the current loop; u d Indicates the actual value of the d-axis voltage of the filter capacitor, u q Indicates the actual value of the q-axis voltage of the filter capacitor.

13. The setting device according to claim 12, characterized in that: The modulation voltage reference value satisfies: Wherein, T represents the control period; k represents the high-frequency suppression constant, and k ≥ 1.

14. The setting device according to claim 13, characterized in that: The setting module is specifically used for: According to the modulation voltage reference value, the second proportional coefficient is set to The second integral coefficient is set to 0.

15. A computer device, characterized in that: include: one or more processors; The processor is configured to store one or more programs; When the one or more programs are executed by the one or more processors, the tuning method according to any one of claims 1 to 7 is implemented.

16. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed, the setting method according to any one of claims 1 to 7 is implemented.

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