CN-116388214-B - Method and device for setting control parameters of grid-structured converter

CN116388214BCN 116388214 BCN116388214 BCN 116388214BCN-116388214-B

Abstract

The application discloses a method and a device for setting control parameters of a grid-built current transformer, wherein the method comprises the steps of solving a closed loop transfer function of a first current control link, obtaining inequality constraint which is required to be met by an active-frequency outer loop control parameter under a preset stability requirement by utilizing a Lawster criterion, solving the inequality constraint under a preset dynamic performance requirement to set the active-frequency outer loop control parameter, solving a closed loop transfer function of a second current control link to set a reactive-voltage outer loop control parameter, determining parameter selection ranges of virtual inductance and virtual resistance according to the inductance of the current transformer to set virtual impedance control parameters, solving the closed loop transfer function of a third current control link, and solving the inequality constraint which is required to be met by a current inner loop control parameter under the preset dynamic performance requirement to set the current inner loop control parameter. Therefore, the technical problems that in the related art, the efficiency of parameter setting based on experience or trial and error is low, and optimal control parameters are difficult to find are solved.

Inventors

ZHAO WEI
XIE XIAORONG
LI FUQIANG
Liu Pengyin
PAN YAN
ZHANG JING
XU PENG
DONG YE

Assignees

清华大学
国家电网有限公司华北分部

Dates

Publication Date: 20260505
Application Date: 20220908

Claims (10)

1. The method for setting the control parameters of the grid-structured converter is characterized by comprising the following steps of: Solving a closed loop transfer function of a first current control link, obtaining inequality constraint which is required to be met by an active-frequency outer loop control parameter under a preset stability requirement by utilizing a Lawster criterion, and solving the inequality constraint which is required to be met by the active-frequency outer loop control parameter under a preset dynamic performance requirement so as to set the active-frequency outer loop control parameter; Solving a closed loop transfer function of a second current control link, and obtaining inequality constraint which is required to be met by the reactive-voltage outer loop control parameter under the preset stability requirement by utilizing the Lawster criterion so as to set the reactive-voltage outer loop control parameter; determining the parameter selection range of virtual inductance and virtual resistance according to the inductance of the converter to set the virtual impedance control parameter, and Solving a closed loop transfer function of a third current control link, obtaining inequality constraint which is required to be met by the current inner loop control parameter under the preset stability requirement by utilizing the Lawster criterion, and solving equality constraint which is required to be met by the current inner loop control parameter under the preset dynamic performance requirement so as to set the current inner loop control parameter; The closed loop transfer function of the first current control link is as follows: , wherein U is the outlet voltage of the converter, The voltage is output for the switching device of the current transformer, As an equivalent inertial time constant, As a result of the first damping coefficient, For the purpose of adjusting the coefficient of effect for the frequency, S is Laplacian operator, which is the total reactance of the converter; the closed loop transfer function of the second current control link is as follows: , Wherein, the And Proportional and integral gain of the PI link in the reactive-voltage outer loop control link; The closed loop transfer function of the third current control link is as follows: , , Wherein, the 、、 And The proportional and integral gains of the PI control link, For the power electronic switch action time, R and L are respectively a converter resistor and an inductor.
2. The method of claim 1, wherein the inequality constraint that the active-frequency outer loop control parameter should satisfy comprises: First stability constraint: , and, a first dynamic performance constraint: , Wherein, the Is the second damping coefficient.
3. The method according to claim 1, characterized in that the second stability constraint that the reactive-voltage outer loop control parameter should meet is: 。
4. The method of claim 1, wherein the equality constraints that should be satisfied by the current inner loop control parameters include: Third stability constraint: ; And, a second dynamic performance constraint: 。
5. the utility model provides a net formula converter control parameter setting device which characterized in that includes: The first calculation module is used for solving a closed loop transfer function of a first current control link, obtaining inequality constraint which is required to be met by the active-frequency outer loop control parameter under the preset stability requirement by utilizing a Lawster criterion, and solving the inequality constraint which is required to be met by the active-frequency outer loop control parameter under the preset dynamic performance requirement so as to set the active-frequency outer loop control parameter; The second calculation module is used for solving a closed loop transfer function of a second current control link, and obtaining inequality constraint which is required to be met by the reactive-voltage outer loop control parameter under the preset stability requirement by utilizing the Lawster criterion so as to set the reactive-voltage outer loop control parameter; A determining module for determining the parameter selection range of the virtual inductance and the virtual resistance according to the current transformer inductance to set the virtual impedance control parameter, and The third calculation module is used for solving a closed loop transfer function of a third current control link, obtaining inequality constraint which is required to be met by the current inner loop control parameter under the preset stability requirement by utilizing the Lawster criterion, and solving equality constraint which is required to be met by the current inner loop control parameter under the preset dynamic performance requirement so as to set the current inner loop control parameter; The closed loop transfer function of the first current control link is as follows: , wherein U is the outlet voltage of the converter, The voltage is output for the switching device of the current transformer, As an equivalent inertial time constant, As a result of the first damping coefficient, For the purpose of adjusting the coefficient of effect for the frequency, S is Laplacian operator, which is the total reactance of the converter; the closed loop transfer function of the second current control link is as follows: , Wherein, the And Proportional and integral gain of the PI link in the reactive-voltage outer loop control link; The closed loop transfer function of the third current control link is as follows: , , Wherein, the 、、 And The proportional and integral gains of the PI control link, For the power electronic switch action time, R and L are respectively a converter resistor and an inductor.
6. The apparatus of claim 5, wherein the inequality constraint that the active-frequency outer loop control parameter should satisfy comprises: First stability constraint: , and, a first dynamic performance constraint: , Wherein, the Is the second damping coefficient.
7. The apparatus of claim 5, wherein the second stability constraint that the reactive-voltage outer loop control parameter should satisfy is: 。
8. The apparatus of claim 5, wherein the equality constraint that the current inner loop control parameter should satisfy comprises: Third stability constraint: ; And, a second dynamic performance constraint: 。
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the method of tuning control parameters of a grid-tied converter as claimed in any one of claims 1 to 4.
10. A computer-readable storage medium having stored thereon a computer program, characterized in that the program is executed by a processor for realizing the grid-built converter control parameter setting method according to any one of claims 1-4.

Description

Method and device for setting control parameters of grid-structured converter Technical Field The application relates to the technical field of analysis and control of power systems, in particular to a method and a device for setting control parameters of a grid-built converter. Background The power system has obvious 'high-proportion power electronics' characteristics on the power transmission, distribution and power utilization sides, and the grid-connected strategy of the power electronic converter is generally divided into a follow-grid type and a grid-structured type. The control strategy of the follow-up network type is provided earlier, and the control strategy of the follow-up network type is widely applied to an electric power system, but the follow-up network type control depends on a phase-locked loop to track the voltage phase of a power grid, so that the electromagnetic oscillation problem is easy to occur under the condition of weak power grid, and the follow-up network type control does not have the inertia characteristic of a traditional synchronous unit. In order to solve the problems, a network-structured control strategy is proposed in some researches, and the strategy does not depend on a phase-locked loop, can establish voltage and frequency, and has good stability in a weak power grid. A typical strategy in the network-structured control strategy is virtual synchronous machine control simulating a traditional synchronous machine rotor motion equation. At present, researches on the grid-structured converter mainly concentrate on analyzing and improving the control performance of the grid-structured converter, and researches on parameter setting are less, in the related technology, parameter setting can be carried out based on experience or trial and error, so that the setting efficiency is low, optimal control parameters are difficult to find, the balance between stability and control dynamic performance cannot be realized, and the improvement is needed. Disclosure of Invention The application provides a method and a device for setting control parameters of a grid-built converter, which are used for solving the technical problems that in the related art, parameter setting is carried out based on experience or trial and error, the setting efficiency is low, and optimal control parameters are difficult to find, so that the stability and the control dynamic performance are both realized. An embodiment of the first aspect of the application provides a grid-built current transformer control parameter setting method, which comprises the steps of solving a closed loop transfer function of a first current control link, obtaining inequality constraint which is required to be met by an active-frequency outer loop control parameter under a preset stability requirement by using a Lawster criterion, solving the inequality constraint which is required to be met by the active-frequency outer loop control parameter under the preset dynamic performance requirement, so as to set the active-frequency outer loop control parameter, solving a closed loop transfer function of a second current control link, obtaining the inequality constraint which is required to be met by a reactive-voltage outer loop control parameter under the preset stability requirement by using the Lawster criterion, so as to set the reactive-voltage outer loop control parameter, determining a parameter selection range of a virtual inductance and a virtual resistance according to the current transformer inductance, so as to set the virtual impedance control parameter, and solving a closed loop transfer function of a third current inner loop control parameter under the preset stability requirement by using the Lawster criterion, and solving the inequality constraint which is required to be met by the current inner loop control parameter under the preset dynamic performance requirement, so as to set the current inner loop control parameter. Optionally, in one embodiment of the present application, the closed loop transfer function of the first current control link is: Wherein U is the converter outlet voltage, E q is the converter switching device output voltage, T J is the equivalent inertia time constant, D p is the first damping coefficient, K f is the frequency adjustment effect coefficient, X s is the converter total reactance, and s is the Laplacian operator. Optionally, in one embodiment of the present application, the inequality constraint that the active-frequency outer loop control parameter should satisfy includes: First stability constraint: and, a first dynamic performance constraint: Wherein ζ is the second damping coefficient. Optionally, in an embodiment of the present application, the closed loop transfer function of the second current control link is: Wherein, K pQ and K iQ are proportional and integral gains of PI links in the reactive-voltage outer loop control links. Optionally, in one embodiment of the application, th