CN-121984018-A - Minimum inertia demand assessment method, system, equipment and medium for electric power system

CN121984018ACN 121984018 ACN121984018 ACN 121984018ACN-121984018-A

Abstract

The invention discloses a minimum inertia demand assessment method, a system, equipment and a medium of an electric power system, wherein the method comprises the steps of obtaining inertia parameters of different energy forms, and determining inertia representation modes of different energy forms in a high-proportion new energy area according to the inertia parameters; based on the inertia representation mode, carrying out coherence division on a generator set, calculating an area inertia equivalent value according to a division result, constructing a multi-machine frequency response model according to the area inertia equivalent value, aggregating the multi-machine frequency response model to obtain an aggregate frequency response model, combining frequency safety dynamic constraint according to the aggregate frequency response model to obtain a minimum inertia requirement value, introducing an inertia safety ratio quantification index based on the minimum inertia requirement value, and evaluating an inertia safety state and inertia adjustment capability, so that the active supporting capability subjected to comparison evaluation is more accurate.

Inventors

LIU HONGYAN
OUYANG XIA
Wu Jisi
LIU QI
LI TIANCHU

Assignees

海南电网有限责任公司电力科学研究院

Dates

Publication Date: 20260505
Application Date: 20251127

Claims (10)

1. A method for evaluating minimum inertia requirements of an electrical power system, comprising: acquiring inertial parameters of different forms of energy sources, and determining inertia representation modes of different forms of energy sources in a high-proportion new energy source region according to the inertial parameters; based on the inertia representation mode, carrying out coherent division on the generator set, and calculating an area inertia equivalent value according to a division result; Constructing a multi-machine frequency response model according to the regional inertia equivalent value, and aggregating the multi-machine frequency response model to obtain an aggregated frequency response model; Combining frequency safety dynamic constraint according to the aggregation frequency response model to obtain a minimum inertia requirement value; And introducing an inertial safety ratio quantification index based on the minimum inertia demand value, and evaluating an inertial safety state and an inertial adjustment capability.
2. The method for evaluating minimum inertia requirements of an electric power system according to claim 1, wherein determining an inertia characterization mode of each different energy form in a high-proportion new energy region comprises: For rotary power generation equipment, determining an inertia constant according to the ratio of kinetic energy at the rated rotation speed of the rotary power generation equipment to rated capacity; For the power electronic interface type power generation equipment, determining an inertia constant according to the ratio of the energy stored by the direct current bus capacitor of the power electronic interface type power generation equipment to the rated capacity; And taking inertia parameters obtained by the rotary power generation equipment and the power electronic interface type power generation equipment as an inertia representation mode corresponding to the energy form.
3. The power system minimum inertia demand evaluation method of claim 2, wherein calculating the regional inertia equivalent value according to the division result comprises: Clustering the coherence of the internal frequency of the generator by using a first clustering method, and dividing the region of the generator set with similar electromechanical oscillation; And calculating the area inertia equivalent value according to the division result.
4. The method for evaluating the minimum inertia requirement of the electric power system according to claim 3, wherein constructing the multi-machine frequency response model comprises a frequency response model of the hydroelectric generator and a response model of the new energy unit; The method comprises the steps of integrating a rotor motion equation, a water hammer effect model, a transient descent compensation link and a speed regulator model of the hydroelectric generator, and constructing a frequency response model of the hydroelectric generator; And constructing a response model of the new energy unit by constructing a mechanical equation and active-frequency droop control of the virtual synchronous machine and internally coupling the mechanical equation and the active-frequency droop control through a rotor motion equation.
5. The method of power system minimum inertia demand assessment of claim 4, wherein aggregating the multi-machine frequency response model comprises: Polymerizing the multi-machine frequency response model into a single-machine model by utilizing an optimized polymerization method; and establishing a multi-machine frequency response model by utilizing the hydroelectric generator and the frequency response of the new energy unit, simplifying the multi-machine frequency response model, and aggregating parameters of the multi-machine frequency response model to obtain an aggregated frequency response model.
6. The method of claim 5, wherein obtaining the minimum inertia requirement value comprises: obtaining a first minimum inertial value meeting the frequency change rate requirement according to the fact that the absolute value of the actual frequency change rate at the disturbance initial moment cannot exceed a preset safety constraint value; Obtaining a second minimum inertia value meeting the frequency deviation requirement according to the fact that the frequency deviation cannot exceed a preset safety limit value; And comparing the first minimum inertia value with the second minimum inertia value, and taking the maximum value as a minimum inertia requirement value.
7. A method of assessing a minimum inertia requirement of an electrical power system as claimed in claim 1 or claim 6 wherein assessing an inertial safety condition and inertial regulation capability comprises: obtaining an inertia safety ratio through the ratio of the current inertia value to the minimum inertia required value; If the inertia safety ratio is greater than a first threshold, the power system is safe; If the inertia safety ratio is smaller than or equal to a first threshold value and larger than or equal to 1, the electric power system is relatively safe; if the inertia safety ratio is less than the inverse of the first threshold, the power system is unsafe.
8. A power system minimum inertia demand assessment system employing a power system minimum inertia demand assessment method according to any one of claims 1-7, comprising: The inertia calculation module is used for acquiring inertia parameters of different energy forms and determining inertia representation modes of each different energy form in the high-proportion new energy area according to the inertia parameters; The frequency response modeling module is used for carrying out coherent division on the generator set based on the inertia representation mode, and calculating an area inertia equivalent value according to a division result; The model aggregation module is used for constructing a multi-machine frequency response model according to the regional inertia equivalent value and aggregating the multi-machine frequency response model to obtain an aggregated frequency response model; The inertia constraint module is used for obtaining a minimum inertia requirement value according to the aggregation frequency response model and frequency safety dynamic constraint; And the inertia evaluation module is used for introducing an inertia safety ratio quantification index based on the minimum inertia demand value to evaluate the inertia safety state and the inertia adjustment capability.
9. A computer device comprising a memory and a processor, the memory storing a computer program, the processor implementing the steps of a method for estimating minimum inertia requirements of an electrical power system according to any of claims 1 to 7 when the computer program is executed.
10. A computer-readable storage medium, characterized in that a computer program is stored thereon, which, when being executed by a processor, implements the steps of a method for evaluating minimum inertia requirements of an electrical power system according to any of claims 1 to 7.

Description

Minimum inertia demand assessment method, system, equipment and medium for electric power system Technical Field The invention relates to the technical field of power electronics, in particular to a method, a system, equipment and a medium for evaluating minimum inertia requirements of a power system. Background Currently, renewable energy sources represented by photovoltaic and wind power have not been developed at a previous speed in order to cope with the challenges of global climate change and exhaustion of fossil energy. However, the new energy power generation equipment is connected with the grid through the power electronic inverter, and the inherent maximum power point tracking running mode and decoupling characteristic with the frequency of the power grid of the new energy power generation equipment replace the rotary inertia of the traditional synchronous generator set. This results in high-proportion new energy power systems exhibiting low inertia, weak damping typical characteristics, and system frequency stability is under serious test. In the traditional synchronous system, the huge rotational inertia can effectively slow down the frequency change rate after disturbance, and precious response time is won for control measures such as primary frequency modulation and the like. However, in a system with high new energy duty ratio, the equivalent inertia level of the system is obviously reduced, the frequency change rate after disturbance is rapidly increased, and the anti-islanding protection of the distributed power supply is easily triggered. The low inertia level reduces the lowest point of the system frequency, greatly increases the risk of triggering and even crossing a third defense line such as low-frequency load shedding and the like, and finally leads to system frequency breakdown and large-scale power failure accidents. Existing inertia evaluation methods typically use all network nodes as sampling points. Because the frequency dynamic responses of the nodes with similar electric distances have high similarity, the existing inertia evaluation method causes the problems of redundancy of sampling points, huge data volume and low calculation efficiency, and the urgent requirements of a dispatching center on quick sensing and real-time monitoring of the regional inertia level are difficult to meet. The regional equivalent inertia method simplifies a complex system into a plurality of representative equivalent regions by aggregating nodes with similar electric distances and similar dynamic characteristics and power supplies. By considering the minimum inertia requirement necessary for frequency stabilization, accurate regulation and control and resource optimization configuration can be realized. And comparing the current inertia value with a dynamic minimum inertia requirement threshold value to effectively identify risks and guide regulation. In view of the above, in view of the new challenges of frequency stabilization brought by high-ratio new energy power systems, it is now necessary to research a minimum inertia requirement evaluation method for power systems to solve the above problems. Disclosure of Invention In view of the above existing problems, the present invention provides a method, a system, a device and a medium for evaluating minimum inertia requirements of an electric power system. The invention provides a method, a system, equipment and a medium for evaluating minimum inertia requirement of an electric power system, which solve the problems that the inertia of the electric power system cannot be evaluated accurately and the frequency is safe and controlled under high-proportion new energy access. In order to solve the technical problems, the invention provides the following technical scheme: in a first aspect, the present invention provides a method for evaluating minimum inertia requirements of an electric power system, including: acquiring inertial parameters of different forms of energy sources, and determining inertia representation modes of different forms of energy sources in a high-proportion new energy source region according to the inertial parameters; based on the inertia representation mode, carrying out coherent division on the generator set, and calculating an area inertia equivalent value according to a division result; Constructing a multi-machine frequency response model according to the regional inertia equivalent value, and aggregating the multi-machine frequency response model to obtain an aggregated frequency response model; Combining frequency safety dynamic constraint according to the aggregation frequency response model to obtain a minimum inertia requirement value; And introducing an inertial safety ratio quantification index based on the minimum inertia demand value, and evaluating an inertial safety state and an inertial adjustment capability. As an optimal scheme of the minimum inertia demand evaluation method of the electric power system, the me