CN-121984136-A - Network-structured converter, control method thereof, controller and storage medium

CN121984136ACN 121984136 ACN121984136 ACN 121984136ACN-121984136-A

Abstract

The application provides a grid-formed converter, a control method, a controller and a storage medium thereof, and relates to the technical field of converter control, wherein the method comprises the steps of generating an active current reference value according to an active power reference value and a grid-connected point voltage amplitude, and generating a reactive current reference value according to a reactive power reference value and a grid-connected point voltage amplitude; the method comprises the steps of obtaining an active current reference value and an actual value through a proportional controller to obtain a q-axis modulation voltage component, obtaining a reactive current reference value and an actual value through the proportional controller to obtain a d-axis modulation voltage component, generating a d-axis modulation voltage reference value according to the d-axis voltage reference value, the d-axis modulation voltage component and an active virtual resistor voltage drop, generating a q-axis modulation voltage reference value according to the q-axis modulation voltage component and the reactive virtual resistor voltage drop, and carrying out coordinate transformation on the d-axis modulation voltage reference value and the q-axis modulation voltage reference value based on a synchronous angle instruction to generate a final modulation signal of the grid-structured converter. The application can solve the problem of poor stability of the grid-structured converter under a strong power grid.

Inventors

LI MENGJIE
ZHANG YUANZE
WANG BAOJI
HAN FENG

Assignees

阳光电源股份有限公司

Dates

Publication Date: 20260505
Application Date: 20251215

Claims (10)

1. The control method of the grid-structured converter is characterized by comprising the following steps of: acquiring an active power reference value, a reactive power reference value and a grid-connected point voltage amplitude; Generating an active current reference value according to the active power reference value and the grid-connected point voltage amplitude, and generating a reactive current reference value according to the reactive power reference value and the grid-connected point voltage amplitude; acquiring an active current actual value and a reactive current actual value, wherein the active current reference value and the active current actual value pass through a proportional controller to obtain a q-axis modulation voltage component, and the reactive current reference value and the reactive current actual value pass through the proportional controller to obtain a d-axis modulation voltage component; Acquiring a d-axis voltage reference value, an active virtual resistance voltage drop and a reactive virtual resistance voltage drop, generating a d-axis modulation voltage reference value according to the d-axis voltage reference value, the d-axis modulation voltage component and the active virtual resistance voltage drop, and generating a q-axis modulation voltage reference value according to the q-axis modulation voltage component and the reactive virtual resistance voltage drop; and acquiring a synchronous angle instruction, and performing coordinate transformation on the d-axis modulation voltage reference value and the q-axis modulation voltage reference value based on the synchronous angle instruction to generate a final modulation signal of the grid-structured converter.
2. The method for controlling a grid-tied converter according to claim 1, wherein generating an active current reference value from the active power reference value and the grid-tie point voltage amplitude, and generating a reactive current reference value from the reactive power reference value and the grid-tie point voltage amplitude, comprises: dividing the active power reference value by the grid-connected point voltage amplitude to obtain an active current reference value; dividing the reactive power reference value by the grid-connected point voltage amplitude and taking the negative value to obtain a reactive current reference value.
3. The control method of a grid-connected converter according to claim 1, wherein the q-axis modulation voltage component is obtained by passing the active current reference value and the active current actual value through a proportional controller, comprising: and the deviation between the active current reference value and the active current actual value is used for obtaining a q-axis modulation voltage component through a proportional controller.
4. The control method of a grid-connected converter according to claim 1, wherein the reactive current reference value and the reactive current actual value obtain d-axis modulation voltage components through a proportional controller, comprising: And the deviation between the reactive current reference value and the reactive current actual value is used for obtaining a d-axis modulation voltage component through a proportional controller.
5. The method for controlling a grid-connected converter according to claim 1, wherein the obtaining the d-axis voltage reference value, the active virtual resistance drop, and the reactive virtual resistance drop includes: Obtaining reactive power reference value and grid-connected point voltage rated value, adding the grid-connected point voltage rated value after the reactive power reference value and the reactive power pass through a proportional integral controller, and obtaining d-axis voltage reference value; and obtaining a virtual resistance value, multiplying the actual value of the active current by the virtual resistance value to obtain an active virtual resistance voltage drop, and multiplying the actual value of the reactive current by the virtual resistance value to obtain a reactive virtual resistance voltage drop.
6. The method of claim 1, wherein generating the d-axis modulation voltage reference value based on the d-axis voltage reference value, the d-axis modulation voltage component, and the active virtual resistor voltage drop comprises: and subtracting the d-axis modulation voltage component from the d-axis voltage reference value, and subtracting the active virtual resistor voltage drop to obtain a d-axis modulation voltage reference value.
7. The method of controlling a grid-tied converter according to claim 1, wherein the generating a q-axis modulated voltage reference value from the q-axis modulated voltage component and the reactive virtual resistance drop comprises: And subtracting the reactive virtual resistance voltage drop from the q-axis modulation voltage component to obtain a q-axis modulation voltage reference value.
8. A controller for implementing a method of controlling a grid-tied converter according to any one of claims 1 to 7.
9. A grid-tied converter comprising the controller of claim 8.
10. A storage medium having stored thereon a computer program which, when executed by a processor, implements a method of controlling a grid-built converter as claimed in any one of claims 1 to 7.

Description

Network-structured converter, control method thereof, controller and storage medium Technical Field The application relates to the technical field of converter control, in particular to a grid-connected converter, a control method thereof, a controller and a storage medium. Background When the grid-structured converter is connected to an alternating current power grid, frequency and voltage support is provided for the power grid, and the stability of the novel power system is improved. The control strategy of the grid-connected converter can be divided into direct grid-connected control and indirect grid-connected control according to whether the voltage-current inner loop is contained or not, wherein the indirect grid-connected control has the voltage-current inner loop, the direct grid-connected control has no voltage-current inner loop, and the voltage amplitude and the phase of the grid-connected converter are directly output. The grid-structured converter controlled by direct grid structure is low in stability when being connected with a strong power grid, easy to occur risk of undershoot vibration instability, and greatly reduced in power response control bandwidth and response speed due to large line impedance and reduced power angle coefficient when being connected with an extremely weak power grid. Therefore, the grid-structured converter has poor stability under a strong power grid, and is a technical problem to be solved urgently by the person skilled in the art. Disclosure of Invention The application provides a grid-connected converter, a control method thereof, a controller and a storage medium, which are used for solving the problem of poor stability of the grid-connected converter under a strong power grid. According to a first aspect of an embodiment of the present application, there is provided a control method of a grid-connected converter, including: acquiring an active power reference value, a reactive power reference value and a grid-connected point voltage amplitude; Generating an active current reference value according to the active power reference value and the grid-connected point voltage amplitude, and generating a reactive current reference value according to the reactive power reference value and the grid-connected point voltage amplitude; acquiring an active current actual value and a reactive current actual value, wherein the active current reference value and the active current actual value pass through a proportional controller to obtain a q-axis modulation voltage component, and the reactive current reference value and the reactive current actual value pass through the proportional controller to obtain a d-axis modulation voltage component; Acquiring a d-axis voltage reference value, an active virtual resistance voltage drop and a reactive virtual resistance voltage drop, generating a d-axis modulation voltage reference value according to the d-axis voltage reference value, the d-axis modulation voltage component and the active virtual resistance voltage drop, and generating a q-axis modulation voltage reference value according to the q-axis modulation voltage component and the reactive virtual resistance voltage drop; and acquiring a synchronous angle instruction, and performing coordinate transformation on the d-axis modulation voltage reference value and the q-axis modulation voltage reference value based on the synchronous angle instruction to generate a final modulation signal of the grid-structured converter. Optionally, the generating an active current reference value according to the active power reference value and the grid-connected point voltage amplitude, and generating a reactive current reference value according to the reactive power reference value and the grid-connected point voltage amplitude, includes: dividing the active power reference value by the grid-connected point voltage amplitude to obtain an active current reference value; dividing the reactive power reference value by the grid-connected point voltage amplitude and taking the negative value to obtain a reactive current reference value. Optionally, the q-axis modulation voltage component is obtained by the active current reference value and the active current actual value through a proportional controller, including: and the deviation between the active current reference value and the active current actual value is used for obtaining a q-axis modulation voltage component through a proportional controller. Optionally, the d-axis modulation voltage component is obtained by the reactive current reference value and the reactive current actual value through a proportional controller, including: And the deviation between the reactive current reference value and the reactive current actual value is used for obtaining a d-axis modulation voltage component through a proportional controller. Optionally, the obtaining the d-axis voltage reference value, the active virtual resistance drop and the reactive vi