CN-121984007-A - Electric power and electric quantity balance optimization method under high-proportion new energy access

CN121984007ACN 121984007 ACN121984007 ACN 121984007ACN-121984007-A

Abstract

The invention relates to the technical field of power systems, and discloses a power and electricity balance optimization method under high-proportion new energy access, which comprises the following steps of quantifying supply and demand unbalance caused by insufficient peak regulation capacity and insufficient capacity of a power transmission channel; based on the node adjustment capability deficiency index and the line full-load duration ratio index, weak nodes and bottleneck lines of the system are identified, an energy storage configuration candidate node set and a line extension candidate line set are generated, inter-regional flexibility mutual-aid constraint and flexibility adjustment factors are established, quantitative adjustment and contribution assessment of trans-regional flexible resources are realized, a double-layer optimization model with the maximum new energy consumption rate as an outer layer target and the minimum regional injection power and tie line power fluctuation as an inner layer target is established, and an optimization scheme is obtained through iterative solution.

Inventors

ZHAO WEIJIE
JIANG YI
HUANG JIANXIANG
ZHANG QIHAO
Zha Liyun
LIU KUN

Assignees

中国南方电网有限责任公司超高压输电公司昆明局

Dates

Publication Date: 20260505
Application Date: 20251222

Claims (10)

1. The power and electricity balance optimization method under high-proportion new energy access is characterized by comprising the following steps of, The supply and demand unbalance caused by insufficient peak regulation capacity and insufficient capacity of a power transmission channel is quantified; Constructing a node adjustment capacity deficiency index and a line full-load duration ratio index, identifying weak nodes and bottleneck lines of a system, and generating an energy storage configuration candidate node set and a line extension candidate line set; Establishing inter-regional flexibility mutual-aid constraint and flexibility adjustment factors, and realizing quantitative allocation and contribution assessment of cross-regional flexibility resources; And constructing a double-layer optimization model with the maximum new energy consumption rate as an outer layer target and the minimum regional injection power and tie line power fluctuation as an inner layer target, and carrying out iterative solution to obtain an optimization scheme.
2. The method for optimizing power and electric quantity balance under high-proportion new energy access according to claim 1 is characterized in that the supply and demand unbalance quantification caused by insufficient peak shaving capacity is calculated as follows: ; In the formula, The load shedding power of the system at the time t caused by insufficient forward peak regulation capacity; the net load power of the system at the time t; The maximum technical output of the unit at the time t can be adjusted for the system; ; In the formula, The method comprises the steps of (1) discarding wind and discarding light power caused by insufficient negative peak regulation capacity at the time t of a system; The minimum technical output of the unit at the time t can be adjusted for the system.
3. The method for optimizing power and electric quantity balance under high-proportion new energy access according to claim 1 is characterized in that the supply and demand unbalance quantification caused by the insufficient capacity of a power transmission channel is calculated as follows: ; In the formula, The load power is cut off at the moment t, which is caused by insufficient capacity of a power transmission channel of a load node i; load demand for load node i; The local generating capacity of the load node i; The power flow of the power transmission line from the node j to the load node i is achieved; is a node set connected with the node i; ; In the formula, The energy source node j is wind-discarding and light-discarding power caused by insufficient capacity of a power transmission channel at the moment t; Generating energy for new energy of the node j; Is the set of nodes connected to node j.
4. The method for optimizing power and electricity balance under high-proportion new energy access according to claim 1, wherein the calculation of the node adjustment capability deficiency index is as follows: define node adjustment capability average shortfall: ; ; In the formula, 、 The average shortages of the upward and downward adjustment capability of the node i are respectively; 、 The load shedding amount and the wind discarding amount of the node i at the time t are respectively; 、 Respectively the total number of time periods with insufficient upward and downward adjusting capability; Computing node discrete degrees of up and down adjustment capability shortfall: ; ; In the formula, 、 The discrete degrees of insufficient upward and downward adjustment capability of the nodes are respectively represented by t 1 , t 2 , and t 1 , wherein the moment of insufficient upward adjustment capability is represented by the moment of insufficient downward adjustment capability of the nodes; ; ; ; In the formula, And (5) adjusting the capacity deficiency index for the node.
5. The method for optimizing power and electricity balance under high-proportion new energy access according to claim 4, wherein the calculation of the line full-load duration ratio index is as follows: Defining a load factor as a ratio of line active power flow to line transmission capacity: ; In the formula, Load rate of the branch ij at the t period; Active power flow through branch ij for period t; The active transmission limit for branch ij; ; In the formula, The full-load duration ratio of the line ij in the operation period is set; 、 The non-full period and full period of line ij are respectively.
6. The method for optimizing power and electricity balance under high-proportion new energy access of claim 5, wherein generating the set of energy storage configuration candidate nodes and the set of line extension candidate lines comprises, Setting a threshold value When (when) When the node i is included in the energy storage configuration candidate node set; Setting a threshold value When (when) When the line ij is included in the line extension candidate line set.
7. The method for optimizing power and electricity balance under high-proportion new energy access according to claim 1, wherein the inter-region flexibility mutual constraint is as follows: ; ; ; ; ; In the formula, The amount of up-regulation flexibility mutual aid provided to region j for region i; The amount of turndown flexibility mutual aid provided for region i to region j; the amount of turndown flexibility mutual aid provided to region i for region j; is the mutual-aid amount in the opposite direction; up-regulating flexible supply capacity for the conventional units of the area i; the ability to provide flexibility for the energy storage downregulation of region i; the capacity of the energy storage up-regulation flexibility of the region i is provided; 、 and the flexible supply capacity is respectively adjusted up and down for the interconnected power grids between the areas i and j.
8. The method for optimizing power and electricity balance under high-proportion new energy access according to claim 1, wherein the flexibility adjustment factor is defined as: ; ; In the formula, And Respectively adjusting flexibility adjusting factors for up-regulation and down-regulation of the resource s at the time t; Respectively a conventional unit, energy storage and an interconnected power grid; Is a resource At the moment of time The provided up-regulation flexible supply amount; Is a resource At the moment of time The provided down-regulation flexibility supply amount; At the moment for the system Is provided for the overall up-regulation flexibility of (a); At the moment for the system Is provided for the overall turndown flexibility of (c).
9. The method for optimizing electric power and electric quantity balance under high-proportion new energy access according to claim 1, wherein the outer layer model objective function of the double-layer optimization model is as follows: ; In the formula, Is an outer layer objective function; The total amount of new energy consumption of the interconnected power grid under multiple scenes; The total amount of power generation for new energy sources is available; Constraints of the outer layer model include: Energy storage planning total capacity constraint: ; ; In the formula, And Respectively planning energy storage power and capacity for the region i; And Planning total power and total capacity for the whole network energy storage respectively; energy storage power-capacity ratio constraint: ; In the formula, And Respectively the minimum and maximum rated charge-discharge time length of the stored energy; Energy storage configuration constraint based on weak link identification: ; In the formula, Is a node Is used for storing energy to configure the power capacity; a minimum power capacity lower limit configured for the node energy storage; Is a node An insufficient adjustment capability index; the maximum value of the capacity deficiency degree is regulated for all nodes in the system; A set of nodes is configured for the candidate energy storage.
10. The method for optimizing electric power and electric quantity balance under high-proportion new energy access according to claim 1, wherein the inner layer model objective function of the double-layer optimization model is as follows: ; In the formula, Is an inner layer objective function; probability of occurrence for scene s; the injection power of the region i in the scene s at the time t is given; Transmitting power for the link from region i to region j in scene s; constraints of the inner layer model include: node power balancing constraints: ; ; In the formula, The output of the conventional unit is provided; The power is output for renewable energy sources; the energy storage charge and discharge power; Is the load power; flexible supply and demand balance constraint: ; ; In the formula, 、、 Index of the conventional unit, energy storage and connecting line respectively; the up-regulation flexibility of the conventional unit is realized; up-regulation flexibility provided for energy storage; the flexibility of up-regulation provided for the tie-line; up-regulation flexibility requirements required for the system; the method is the down-regulation flexibility of the conventional unit; The down-regulation flexibility provided for energy storage; The flexibility of down-regulation provided for the tie-line; the requirement of the system for the down-regulation flexibility is required; Energy storage operation constraint: ; ; ; ; In the formula, Minimum charging power for energy storage; is the charging power; Is the discharge power; the maximum discharge power is stored; The energy storage electric quantity is at the time t; Is the time step; The discharging and charging efficiency is achieved; is the discharge efficiency; And The lower limit and the upper limit of the stored charge state are respectively.

Description

Electric power and electric quantity balance optimization method under high-proportion new energy access Technical Field The invention relates to the technical field of power systems, in particular to a power and quantity balance optimization method under high-proportion new energy access. Background The permeability of new energy sources such as wind power, photovoltaic and the like in an electric power system continuously rises. By the end of 2024, the installed capacity of new energy in China breaks through 1400 GW, and the new energy permeability in 2025 is expected to reach 55%. The access of the high-proportion new energy source enables the power system to show obvious uncertainty and fluctuation, and the traditional mode of 'deterministic power generation tracking uncertain load' is gradually changed into the mode of 'uncertain power generation and uncertain load bidirectional matching', so that a serious challenge is brought to power and quantity balance. In extreme weather conditions, the problem of insufficient regulation capacity of the system is further exacerbated by severe fluctuations in new energy output. The problem of weak regulation capability of the power system in extreme weather is fully exposed by 2021 in the U.S. Texas storm event and 2023 in the wide-range power failure of China 'Du Surui' typhoons. The existing research is mainly developed from two directions of flexible resource allocation and power balance optimization, but has three defects: First, the adjustment capability weak link identification method is not accurate enough. Most researches adopt global flexibility indexes to evaluate the overall adjustment capability of the system, when and where the insufficient adjustment capability cannot be accurately positioned from the space-time dimension, the supply and demand unbalance caused by the insufficient peak adjustment capability of the nodes or the insufficient capacity of the power transmission channels cannot be distinguished, and the contribution degree of each node and each line to the system flexibility balance cannot be quantized. Secondly, the source tracing mechanism of unbalance of supply and demand is not clear enough. The traditional method mainly considers the net load fluctuation or the climbing rate as a flexibility demand index, fails to distinguish different influences of insufficient peak regulation capacity and power transmission blockage on supply and demand unbalance, and lacks in-depth analysis on supply and demand unbalance sources. Thirdly, the energy storage-power transmission collaborative planning method is to be perfected. The existing energy storage-power transmission joint planning model adopts a sequential mode or only plans a single target area, so that the dynamic coupling relation between the energy storage configuration and the power transmission extension cannot be fully excavated, the difference of the flexible resource distribution and the flexible demand among the areas is ignored, and investment redundancy or resource waste is easily caused. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a power and electricity balance optimization method under high-proportion new energy access. The invention aims at realizing the technical scheme that the power and quantity balance optimization method under high-proportion new energy access comprises the following steps of, The supply and demand unbalance caused by insufficient peak regulation capacity and insufficient capacity of a power transmission channel is quantified; Based on the node adjustment capability deficiency index and the line full-load duration ratio index, identifying weak nodes and bottleneck lines of the system, and generating an energy storage configuration candidate node set and a line extension candidate line set; Establishing inter-regional flexibility mutual-aid constraint and flexibility adjustment factors, and realizing quantitative allocation and contribution assessment of cross-regional flexibility resources; And constructing a double-layer optimization model with the maximum new energy consumption rate as an outer layer target and the minimum regional injection power and tie line power fluctuation as an inner layer target, and carrying out iterative solution to obtain an optimization scheme. Specifically, the supply and demand unbalance quantization caused by insufficient peak shaving capacity is calculated as follows: ; In the formula, The load shedding power of the system at the time t caused by insufficient forward peak regulation capacity; the net load power of the system at the time t; The maximum technical output of the unit at the time t can be adjusted for the system; ; In the formula, The method comprises the steps of (1) discarding wind and discarding light power caused by insufficient negative peak regulation capacity at the time t of a system; The minimum technical output of the unit at the time t can be adj