CN-121984088-A - Stability enhancement control method and device suitable for virtual synchronous new energy grid-connected system

CN121984088ACN 121984088 ACN121984088 ACN 121984088ACN-121984088-A

Abstract

The invention discloses a stability enhancement control method and device suitable for a virtual synchronous new energy grid-connected system, wherein the device comprises the following steps of obtaining electrical parameters of grid-connected points of the grid-connected system, and judging whether the grid-connected system is in a low-voltage ride through mode or not based on the electrical parameters; and introducing the active power regulating item into an input link of an active control loop of the system in a negative feedback mode to adjust the phase reference of the system, realize the balance of active power and enhance the transient stability. The stability enhancement control method and device suitable for the virtual synchronous new energy grid-connected system provided by the invention show remarkable transient stability enhancement effect under the condition of grid short circuit fault.

Inventors

HUANG SEN
BAI YONG
XIANG WANQIN
MA ZEJU
LI TAO

Assignees

重庆电力高等专科学校

Dates

Publication Date: 20260505
Application Date: 20260210

Claims (10)

1. A stability augmentation control method suitable for a virtual synchronous new energy grid-connected system is characterized by comprising the following steps: Acquiring electrical parameters of grid connection points of the grid connection system, and judging whether the grid connection system is in a low voltage ride through mode or not based on the electrical parameters; If the grid-connected system is in a low-voltage ride through mode, calculating an active power adjustment item based on the rated voltage amplitude of the power grid and the voltage amplitude of the fault point of the power grid; And introducing the active power adjustment term into an input link of an active control loop of the system in a negative feedback mode, adjusting the phase reference of the system, realizing the balance of active power and enhancing the transient stability.
2. The method for stability augmentation control of a virtual synchronous new energy grid-connected system of claim 1, wherein the electrical parameters comprise three-phase alternating voltage signals, three-phase alternating current signals and line voltage effective values of grid-connected points; The method for judging whether the grid-connected system is in the low-voltage crossing mode based on the electrical parameters specifically comprises the steps of comparing a line voltage effective value of the grid-connected point with a preset low-voltage crossing threshold, judging that the grid-connected system is in the low-voltage crossing mode when the line voltage effective value is smaller than or equal to the low-voltage crossing threshold, and judging that the grid-connected system is in the normal running mode when the line voltage effective value is larger than the low-voltage crossing threshold.
3. The stability augmentation control method for a virtual synchronization type new energy grid-connected system according to claim 2, further comprising the steps of, after obtaining the electrical parameters of the grid-connected system grid-connected point: Calculating active power and reactive power of the virtual synchronous new energy grid-connected system based on the three-phase alternating voltage signals and the three-phase alternating current signals of the grid-connected point; and feeding the active power and the reactive power back to an active control loop and a reactive control loop of the system respectively.
4. The stability augmentation control method for a virtual synchrony new energy grid-connected system as claimed in claim 3, wherein in the step of calculating the active power adjustment term based on the grid rated voltage amplitude and the grid fault point voltage amplitude, the method comprises the sub-steps of: Converting the three-phase alternating current signal from a three-phase static coordinate system to a two-phase rotating coordinate system to obtain a d-axis current component, comparing the d-axis current component with a preset current safety threshold value, and judging whether a current limiting link is triggered or not; When the current limiting link is not triggered, calculating an active power adjustment item based on the rated voltage amplitude of the power grid, the voltage amplitude of the fault point of the power grid and the voltage reference amplitude; and when the current limiting link is triggered, calculating an active power adjustment item based on the rated voltage amplitude of the power grid, the voltage amplitude of the fault point of the power grid and the output current reference value.
5. The stability augmentation control method for a virtual synchronous new energy grid-connected system according to claim 4, wherein when the current limiting link is not triggered, the active power adjustment term is obtained by the following formula: (one) In the formula (I), the components of the compound, Representing the active power adjustment term(s), Representing the rated voltage amplitude of the power grid, Representing the voltage amplitude at the point of failure of the power grid, Representing a voltage magnitude reference; When the current limiting link is triggered, the active power adjustment term is obtained by the following formula: (II) In the formula (II), the components are mixed, And the output current reference value after the virtual synchronous new energy grid-connected system adopts a d-axis current priority limiting mode is represented.
6. The stability augmentation control method for a virtual synchrony new energy grid-connected system as claimed in claim 5, wherein the voltage amplitude reference is obtained by the following formula: (III) In the formula (III), the compound of the formula (III), Representing a voltage amplitude reference, Which represents the reactive power of the power plant, A reference value for the reactive power is indicated, Represents the reactive sag coefficient of the reactive power, Representing the nominal voltage amplitude.
7. The stability augmentation control method for a virtual synchrony new energy grid-connected system as claimed in claim 5, wherein the adjusted phase reference is obtained by the following formula: (IV) In the formula (IV), the compound represented by the formula (IV), A phase reference is represented and a phase reference is represented, The representation of the laplace operator is provided, Which represents the nominal angular frequency of the device, Representing the virtual coefficient of inertia (f) and, Representing the virtual damping coefficient of the damping device, Indicating the value of the active power reference, Which represents the active power of the electric motor, Representing the active power adjustment term.
8. The utility model provides a stability augmentation controlling means suitable for virtual synchronous formula new forms of energy grid-connected system which characterized in that includes: The judging module is used for acquiring the electrical parameters of the grid-connected point of the grid-connected system and judging whether the grid-connected system is in a low-voltage traversing mode or not based on the electrical parameters; The calculation module is used for calculating an active power adjustment item based on the rated voltage amplitude of the power grid and the voltage amplitude of the fault point of the power grid when the judgment module judges that the grid-connected system is in the low-voltage ride through mode; and the adjusting module is used for introducing the active power adjusting item into an input link of the active control loop in a negative feedback mode so as to adjust the phase reference of the system, realize the balance of active power and enhance the transient stability.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the stability augmentation control method of any one of claims 1 to 7, suitable for use in a virtual synchrony new energy grid-connected system.
10. A computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor realizes the steps of the stability augmentation control method of any one of claims 1 to 7 adapted to a virtual synchrony new energy grid-connected system.

Description

Stability enhancement control method and device suitable for virtual synchronous new energy grid-connected system Technical Field The invention relates to the technical field of new energy power generation, in particular to a stability enhancement control method and device suitable for a virtual synchronous new energy grid-connected system. Background Under the drive of energy crisis and climate change, the global energy structure is accelerated to be transformed to green low carbon, the permeability of new energy represented by wind power and photovoltaic is continuously improved, and the power system represented by the traditional synchronous generator is undergoing deep transformation of power electronics. In the transformation process, the complex coupling relation between large-scale new energy access and the power grid causes fundamental change of the system operation characteristics, and particularly under the condition of weak power grid, the broadband oscillation problem caused by high-proportion new energy access is increasingly prominent. In order to improve the dynamic stability of the new energy grid-connected system, virtual synchronous control with inertia support and damping characteristics can be provided, so that the new energy grid-connected system can actively provide frequency and voltage support for a power grid, and the oscillation instability risk under a weak power grid is remarkably reduced. However, when the power grid suffers from a large disturbance working condition such as a short circuit fault, the safe and stable operation of the virtual synchronous new energy grid-connected system still faces challenges. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a stability enhancement control method and device suitable for a virtual synchronous new energy grid-connected system under power grid faults. In order to solve the technical problems, the invention adopts a technical scheme that a stability enhancement control method suitable for a virtual synchronous new energy grid-connected system is provided, and comprises the following steps: Acquiring electrical parameters of grid connection points of the grid connection system, and judging whether the grid connection system is in a low voltage ride through mode or not based on the electrical parameters; If the grid-connected system is in a low-voltage ride through mode, calculating an active power adjustment item based on the rated voltage amplitude of the power grid and the voltage amplitude of the fault point of the power grid; And introducing the active power adjustment term into an input link of an active control loop in a negative feedback mode to adjust the phase reference of the system, realize the balance of active power and enhance the transient stability. Further, the electrical parameters comprise three-phase alternating voltage signals, three-phase alternating current signals and line voltage effective values of the grid-connected points; The method for judging whether the grid-connected system is in the low-voltage crossing mode based on the electrical parameters specifically comprises the steps of comparing a line voltage effective value of the grid-connected point with a preset low-voltage crossing threshold, judging that the grid-connected system is in the low-voltage crossing mode when the line voltage effective value is smaller than or equal to the low-voltage crossing threshold, and judging that the grid-connected system is in the normal running mode when the line voltage effective value is larger than the low-voltage crossing threshold. Further, after obtaining the electrical parameters of the grid-connected point of the grid-connected system, the method further comprises the following steps: Calculating active power and reactive power of the virtual synchronous new energy grid-connected system based on the three-phase alternating voltage signals and the three-phase alternating current signals of the grid-connected point; and feeding the active power and the reactive power back to an active control loop and a reactive control loop of the system respectively. Further, in the step of calculating the active power adjustment term based on the grid rated voltage amplitude and the grid fault point voltage amplitude, the method comprises the substeps of: Converting the three-phase alternating current signal from a three-phase static coordinate system to a two-phase rotating coordinate system to obtain a d-axis current component, comparing the d-axis current component with a preset current safety threshold value, and judging whether a current limiting link is triggered or not; When the current limiting link is not triggered, calculating an active power adjustment item based on the rated voltage amplitude of the power grid, the voltage amplitude of the fault point of the power grid and the voltage reference amplitude; and when the current limiting link is triggered, calculating a