CN-122022107-A - Power supply capacity analysis and evaluation method for power distribution network

CN122022107ACN 122022107 ACN122022107 ACN 122022107ACN-122022107-A

Abstract

The invention discloses a power supply capacity analysis and assessment method of a power distribution network, which is characterized in that real-time operation data of a network-structured energy storage unit and a network-following energy storage unit in the power distribution network are collected and analyzed, voltage deviation, frequency change and power supply continuous parameters are deeply analyzed, so that the power guarantee capacity of a key load in an extreme case is accurately assessed, quantitative assessment modeling is carried out on the power guarantee capacity of the key load in the power distribution network, starting from voltage deviation, frequency fluctuation and a guarantee duration index, a multi-objective key load guarantee optimization analysis and assessment model is obtained, and an analysis and assessment result is visually displayed, so that researchers and operation engineers can quickly and accurately understand the assessment parameters, analyze the power supply capacity, quickly cope with extreme scenes, and unnecessary loss is reduced. According to the analysis and evaluation method for the power supply capacity of the power distribution network, the power supply guarantee capacity of a key load under an extreme scene is comprehensively analyzed according to factors such as voltage deviation, frequency fluctuation and guarantee duration by analyzing the running state of the power distribution network with the grid-structured/grid-following energy storage units.

Inventors

LU CHAO
LU YU
DENG MENGHUA
LIU YIHUA
SUN ZHIHENG
HONG YU

Assignees

国网上海市电力公司

Dates

Publication Date: 20260512
Application Date: 20241105

Claims (10)

1. The analysis and evaluation method for the power supply capacity of the power distribution network is characterized in that through collecting and analyzing real-time operation data of the grid-structured energy storage units and the grid-following energy storage units in the power distribution network, deep analysis is carried out on voltage deviation, frequency change and power supply continuous parameters, so that the power guarantee capacity of the key load in an extreme condition is accurately evaluated, quantitative evaluation modeling is carried out on the power guarantee capacity of the key load in the power distribution network, starting from voltage deviation, frequency fluctuation and guarantee duration indexes, an optimization analysis and evaluation model for the key load guarantee covering multiple targets is obtained, visual display is carried out on analysis and evaluation results, rapid and accurate understanding and evaluation parameters are facilitated for researchers and operation engineers, analysis of the power supply capacity is realized, extreme scenes are rapidly handled, and unnecessary losses are reduced.
2. The method for analyzing and evaluating power supply capacity of power distribution network according to claim 1, wherein the real-time operation data comprises power distribution network parameters, and the penetration data of distributed new energy and the supply and demand relation of the power market, and the power distribution network parameters comprise historical operation data, geographic information of each transformer substation, installation positions of transformers and load access points.
3. The method for analyzing and evaluating the power supply capacity of a power distribution network according to claim 1, wherein in the quantitative evaluation modeling of the power guarantee capacity of a key load, the technical advantages of the capacity of suppressing broadband oscillation, voltage fault ride-through and black start of the network-structured energy storage and the network-structured energy storage are fully considered, and the two are modeled and an interactive composite model with a power distribution network is formed.
4. The method for analyzing and evaluating the power supply capacity of the power distribution network according to claim 1, wherein the capacity of each operation unit in the target power distribution network is automatically detected, performances of the power distribution network under different working conditions are carefully analyzed, multiple possible operation scenes are constructed and calculated, the scenes are subjected to deep analysis to evaluate the adaptability and toughness of the power distribution network in the face of different challenges such as voltage fluctuation, frequency change and load increase and decrease, and based on the analysis results, detailed operation strategy suggestions are provided to help a power grid operator optimize power grid configuration, improve the power supply guarantee capacity of the power grid to critical loads and ensure stable and reliable operation of the power grid under various extreme and complex conditions.
5. The analysis and evaluation method for power supply capacity of a power distribution network according to claim 1, wherein importance of access loads of different substations is considered when planning calculation is performed, weights of the substations with different importance are considered when quantitative evaluation is performed, operation quality of key loads is improved, operation safety of the key loads is guaranteed, and overall loss of a system is reduced.
6. The method for analyzing and evaluating the power supply capacity of the power distribution network according to claim 1, wherein a distribution network model, operation indexes and operation models of all energy storage units are input into a key load guarantee optimization analysis and evaluation model, all parts are combined through a tide equation, analysis and evaluation results are given, and a control strategy is formulated.
7. The method for analyzing and evaluating the power supply capacity of a power distribution network according to claim 1, wherein the power grid operation is flexibly adjusted to cope with the extreme conditions which may occur by cooperating with the operation states of energy storage on different buses in different areas, taking into account the capacity of each energy storage unit of different nodes.
8. A method of analysing and assessing the power supply capacity of a power distribution network according to claim 7, characterised in that the mathematical models of the grid-formed and the grid-following energy storage units relate to the control strategy of the power electronic converter, the dynamic behaviour of the battery and the interaction with the grid for the co-operation of the respective energy storage units.
9. The method for analyzing and evaluating power supply capacity of power distribution network according to claim 7, wherein the simplified model of the network-structured energy storage system is shown in formula (1), formula (2) and formula (3): Equation (1), equation (2) and equation (3) correspond to the output voltage V out , output current I out and battery dynamic model of the energy storage system, respectively Through the simplified model, a plurality of net-structured energy storage systems can be combined through a tide equation to give an optimal control strategy, And PI control coefficients, E V and E I are voltage values P in and P out , respectively, input and output power, respectively, and E rated is rated capacity.
10. The power supply capacity analysis and evaluation method of the power distribution network according to claim 1 is characterized in that visual display is provided by combining analysis and evaluation results with a network topology diagram of a power system, convenience of real-time operation of the power system is remarkably improved, information intercommunication with the power grid is achieved by accessing an interactive platform of the intelligent power grid, control of the power grid operation is rapid and flexible, and operation processes are simple and convenient.

Description

Power supply capacity analysis and evaluation method for power distribution network Technical Field The invention relates to a power supply capacity analysis and evaluation method of a power distribution network. Background In the power industry today, ensuring the stability and reliability of a distribution network is critical, especially for critical loads that have strict requirements on the continuity of the power supply, such as hospitals, data centers, emergency services, etc. These facilities are extremely dependent on the power supply, any interruption of which may have serious consequences. Thus, both grid-formation and grid-following energy storage units play a vital role in modern distribution networks. The grid-built energy storage units have the unique ability to independently control voltage and frequency, which can simulate the behavior of a conventional synchronous generator. The energy storage unit can provide necessary inertia and damping for the power grid, and the resistance of the system to various disturbances is enhanced. When the power system suffers disturbance, such as frequency fluctuation or voltage sag, the grid-structured energy storage unit can rapidly respond, and the stability of power supply is maintained, which is important for ensuring continuous operation of a key load. Unlike a grid-type energy storage unit, the grid-type energy storage unit relies on the existing voltage and frequency signals of the grid to control its power output. They are generally suitable for environments where grid conditions are good and stable reference signals can be provided. The main function of the grid-following energy storage unit is to store energy in the load low valley and release energy in the peak so as to help balance the supply and demand relationship of the power grid. However, the heel-net energy storage unit does not have the ability to maintain voltage and frequency stability under grid disturbances. In a distribution network containing critical loads, the grid-built energy storage unit can be used as a main grid support device, ensuring that high-quality electric energy can be provided in all cases. At the same time, the heel net energy storage unit can be used as a supplement for energy management and demand side response. By combining the two energy storage units, the flexibility and the robustness of the whole power distribution network can be improved, and the power supply safety of key loads can be ensured. However, there is currently no suitable method for the analytical evaluation of the power supply capacity of a power distribution network comprising grid-built/off-grid energy storage units and critical loads. Disclosure of Invention The invention aims to overcome the defects of the prior art, provides an analysis and evaluation method for power supply capacity of a power distribution network, which is specially designed for the power distribution network comprising a grid-structured/grid-following type energy storage unit and a key load, and comprehensively considers operation constraint and control strategies of the grid-structured/grid-following type energy storage unit by establishing a comprehensive evaluation model, wherein the model aims at the power quality of the key load, so that quantitative evaluation and analysis for the power supply capacity of the power distribution network is realized. According to the technical scheme, the power supply capacity analysis and assessment method for the power distribution network comprises the steps of analyzing and assessing power supply capacity of the power distribution network comprising network-structured/network-following type energy storage units and key loads, collecting and analyzing real-time operation data of the network-structured/network-following type energy storage units and the network-following type energy storage units in the power distribution network, carrying out deep analysis on voltage deviation, frequency change and power supply continuous parameters, accurately assessing power guarantee capacity of the key loads under extreme conditions, carrying out quantitative assessment modeling on the power guarantee capacity of the key loads in the power distribution network, starting from voltage deviation, frequency fluctuation and guarantee duration indexes, obtaining a multi-objective key load guarantee optimization analysis and assessment model, and carrying out visual display on analysis and assessment results, so that researchers and operation engineers can understand assessment parameters quickly and accurately, understand analysis of the power supply capacity, quickly cope with extreme scenes, and reduce unnecessary losses. According to the power supply capacity analysis and evaluation method of the power distribution network, the real-time operation data comprise power distribution network parameters, penetration data of distributed new energy and supply and demand relations of an electric power mar