Flexible resource allocation scheduling method for new energy power system based on comprehensive toughness factor

Abstract

The invention discloses a flexible resource configuration scheduling method for a new energy power system based on a comprehensive toughness factor, and the method comprises the steps: S1, setting initial power parameters, and setting initial flexible resource configuration; s2, constructing a comprehensive scene set through historical power parameters and a probability model; and S3, carrying out toughness evaluation on the electric power system under the current flexible resource configuration condition, firstly establishing a flexible resource model, then establishing an electric power system toughness evaluation model, and calculating load loss under different scene conditions and an electric energy insufficiency expected value under the condition of the current flexible resource configuration proportion k. According to the method, the toughness indexes of different scenes are calculated through the direct current optimal power flow optimization model considering the flexible resources, then the flexible resource configuration proportion is adjusted according to the comparison result of the indexes and the set value, and the lifting priority is arranged according to the development cost of different flexible resources. The flexible resource configuration considering the toughness requirement is realized, and the toughness of the power system is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a flexible resource configuration and scheduling method for a new energy power system with comprehensive resilience factors. Background Art

[0002] In recent years, the frequent occurrence of extreme weather around the world has seriously threatened the safe operation of power systems. The global climate and environment have deteriorated sharply in recent years. Extreme weather events such as droughts, floods, hurricanes, extreme high temperatures and extreme cold have occurred frequently, and disaster losses have continued to increase. As the most important infrastructure, the safe and stable operation of energy and power systems is seriously affected by extreme weather. Extreme weather will not only cause a surge in load in a short period of time, but the sudden deterioration of operating conditions will also increase the failure rate of equipment such as power generation and transmission lines. Natural disasters associated with extreme weather may also cause damage to key facilities such as power plants, transmission lines, power equipment, and dispatching communications. Therefore, the study of power system resilience that describes extremely low probability but extremely high-risk failures such as extreme weather has attracted much attention. The improvement of power system resilience can be achieved through the regulation capabilities of various flexible resources within the system. However, the current level of flexibility of my country's power system is insufficient, and the coordinated response capabilities of flexible power sources and load resources are limited. Therefore, there is an urgent need for a configuration and scheduling method for flexible resources to meet the needs of new power systems for configuring flexible resources. At the same time, it is necessary to fully consider the investment and construction costs of different types of flexible resources, set priorities for the construction and development of flexible power sources, and deeply tap the potential of load resources to achieve more effective demand response. Summary of the invention

[0003] One purpose of the present invention is to propose a flexible resource configuration and scheduling method for a new energy power system that takes resilience factors into consideration. The present invention realizes flexible resource configuration that takes resilience requirements into consideration, thereby effectively improving the resilience of the power system.

[0004] A flexible resource configuration and scheduling method for a new energy power system with comprehensive resilience factors according to an embodiment of the present invention includes the following steps:

[0005] S1. Initial power parameter setting, setting initial flexible resource configuration;

[0006] S2, building a comprehensive scenario set through historical power parameters and probability models;

[0007] S3. Conduct resilience assessment on the power system under the current flexible resource configuration. First, establish a flexible resource model, then establish a power system resilience assessment model, calculate the load loss under different scenarios, and the expected value of power shortage under the current flexible resource configuration ratio k;

[0008] S4. Determine whether the expected value of power shortage meets the resilience requirements and adjust the proportion of flexible resource allocation;

[0009] Optionally, the S1 specifically includes:

[0010] S11. Input basic parameters of power system transmission line data, traditional power source data and load data;

[0011] S12. Set the expected energy shortage value EENS of the power system resilience index set ,EENS set It indicates the expected value of load loss allowed under extreme system conditions;

[0012] S13. Setting an initial flexible resource configuration ratio k0, where k0 represents the ratio of the initial flexible resource capacity to the conventional power supply installed capacity.

[0013] Optionally, it is characterized in that each scenario h of the comprehensive scenario set H includes power grid fault conditions and new energy output.

[0014] Optionally, the power system resilience assessment model specifically includes:

[0015] The DC optimal power flow model of the power system is used as the model for evaluating the resilience of the power grid. The load reduction amount and the expected value of power shortage at each node are calculated. The objective function is:

[0016]

[0017] Among them, f h represents the sum of the conventional unit power generation cost, flexible load demand response cost, energy storage operation cost and load reduction cost of the power system in the hth state; n g 、n ED 、n d and n es They represent the number of conventional generators, grid nodes, flexible loads and energy storage systems in the power system; GC r，h () represents the power generation cost of the rth generator set in the power system under the hth state of the power system; CC i，h () represents the load reduction cost of the i-th power node in the power system under the h-th state of the power system; DC d，h () represents the d-th flexible load demand response cost in the power system under the h-th state; SCe s，h () represents the operating cost of the es-th energy storage system in the power system under the h-th state; represents the active output of the rth generator set in the power system in time period t under the hth state of the power system; represents the load reduction amount of the i-th power node in the power system in time period t under the h-th state of the power system; represents the demand response power of the dth flexible load in the power system in time period t under the hth state of the power system; and They represent the charging and discharging power of the battery energy storage station es in the hth state of the power system during the t period;

[0018] Operation constraints, power balance constraints for each node:

[0019]

[0020] Among them, the set EL represents the set of branches connected to node i; PD i，t represents the load power of node i in period t under normal grid operation, f lt It represents the power flow of line l at time t under normal grid operation;

[0021] The relationship between line power flow and node phase angle:

[0022]

[0023] Among them, θ it ,θ jt They represent the phase angles of nodes i and j at time t under normal operation, respectively, and x l Represents the impedance of line l.

[0024] Transmission line power constraints:

[0025]

[0026] Among them, f l，max Indicates the maximum value of the transmission power of line l;

[0027] Node phase angle constraints:

[0028]

[0029] Among them, θ i，max Indicates the maximum value allowed for the power angle deviation of node i;

[0030] Flexible load resource power upper and lower limit constraints:

[0031]

[0032] Energy storage equipment related constraints:

[0033] The operation of energy storage equipment mainly depends on its state of charge. The charging and discharging process is expressed as:

[0034]

[0035] Where: Indicates the charge state of the battery energy storage station es during the period t; and is the charging and discharging power of the battery energy storage station es during the period t; x es，t is a 0-1 variable representing the battery energy storage state, 0 represents the charging state, and 1 represents the discharging state; η ch and η dis is the charging and discharging efficiency of the battery energy storage power station; C ES is the rated capacity of energy storage;

[0036] In order to achieve stable operation of the energy storage system, its state of charge is limited to a certain range:

[0037]

[0038] Where: and They are the upper and lower limits of the state of charge of the energy storage power station es;

[0039] The upper and lower limits of charging and discharging power of battery energy storage power stations:

[0040]

[0041] in, and They represent the upper and lower limits of power when the battery energy storage station es is charging and the upper and lower limits of power when it is discharging;

[0042] Climbing constraints of various types of regulation resources:

[0043]

[0044] Among them, Rp r，max , R d，max They represent the maximum climbing speed of the conventional unit r, the maximum climbing speed of the energy storage system es during the charging process, the maximum climbing speed of the energy storage system es during the discharging process, and the maximum climbing speed of the flexible load d response;

[0045] Load shedding constraints:

[0046]

[0047] Optionally, the S4 specifically includes:

[0048] The grid resilience index is expressed as the expected value of power shortage. Based on the load reduction, the expected value of power shortage is calculated using the following formula:

[0049]

[0050] Among them, ph represents the probability of scenario h occurring in the power system, and T represents the fault duration under extreme conditions. represents the load reduction of the i-th power node in the power system in time period t under the h-th scenario of the power system;

[0051] Compare the expected energy shortage value EENS with the energy requirement value EENS set If EENS<EEMS set , if the conditions are met, it means that the current flexible resource configuration meets the resilience requirements, and the process ends; if EENS>EENS set , then the flexible resource configuration needs to be adjusted and return to S3;

[0052] Based on the initial value k0, increase Δk to obtain a new flexible resource allocation ratio k, and calculate the required increase in flexible resource capacity ΔC according to the Δk value f , adjust the corresponding flexible resource parameters:

[0053] k=k0+Δk;

[0054] ΔC f =C t Δ k .

[0055] The beneficial effects of the present invention are:

[0056] The present invention proposes a flexible resource configuration and scheduling method for a new energy power system that takes resilience factors into consideration. The method takes into account power grid failure scenarios and new energy output scenarios under different extreme weather conditions, calculates resilience indicators for different scenarios by considering the DC optimal power flow optimization model of flexible resources, and then adjusts the flexible resource configuration ratio based on the comparison results between the indicators and the set values, and arranges the improvement priority according to the development costs of different flexible resources. Flexible resource configuration that takes resilience requirements into consideration is achieved, effectively improving the resilience of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0058] Figure 1 This is a flow chart of a flexible resource configuration and scheduling method for a new energy power system with comprehensive resilience factors proposed by the present invention. DETAILED DESCRIPTION

[0059] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0060] refer to Figure 1 , a flexible resource allocation and scheduling method for a new energy power system with comprehensive resilience factors, comprising the following steps:

[0061] S1. Initial power parameter setting, setting initial flexible resource configuration;

[0062] S2, building a comprehensive scenario set through historical power parameters and probability models;

[0063] S3. Conduct resilience assessment on the power system under the current flexible resource configuration. First, establish a flexible resource model, then establish a power system resilience assessment model, calculate the load loss under different scenarios, and the expected value of power shortage under the current flexible resource configuration ratio k;

[0064] S4. Determine whether the expected value of power shortage meets the resilience requirements and adjust the proportion of flexible resource allocation;

[0065] In this implementation, S1 specifically includes:

[0066] S11. Input basic parameters of power system transmission line data, traditional power source data and load data;

[0067] S12. Set the expected energy shortage value EENS of the power system resilience index set ,EENS set It indicates the expected value of load loss allowed under extreme system conditions;

[0068] S13. Setting an initial flexible resource configuration ratio k0, where k0 represents the ratio of the initial flexible resource capacity to the conventional power supply installed capacity.

[0069] In this implementation, it is characterized in that each scenario h of the comprehensive scenario set H includes a power grid fault situation and a new energy output.

[0070] In this implementation, the power system resilience assessment model specifically includes:

[0071] The DC optimal power flow model of the power system is used as the model for evaluating the resilience of the power grid. The load reduction amount and the expected value of power shortage at each node are calculated. The objective function is:

[0072]

[0073] Among them, f h represents the sum of the conventional unit power generation cost, flexible load demand response cost, energy storage operation cost and load reduction cost of the power system in the hth state; n g 、n ED 、n d and n esThey represent the number of conventional generators, grid nodes, flexible loads and energy storage systems in the power system; GC r，h () represents the power generation cost of the rth generator set in the power system under the hth state of the power system; CC i，h () represents the load reduction cost of the i-th power node in the power system under the h-th state of the power system; DC d，h () represents the d-th flexible load demand response cost in the power system under the h-th state; SC es，h () represents the operating cost of the es-th energy storage system in the power system under the h-th state; represents the active output of the rth generator set in the power system in time period t under the hth state of the power system; represents the load reduction amount of the i-th power node in the power system in time period t under the h-th state of the power system; represents the demand response power of the dth flexible load in the power system in time period t under the hth state of the power system; and They represent the charging and discharging power of the battery energy storage station es in the hth state of the power system during the t period;

[0074] Operation constraints, power balance constraints for each node:

[0075]

[0076] Among them, the set EL represents the set of branches connected to node i; PD i，t represents the load power of node i in period t under normal grid operation, f lt It represents the power flow of line l at time t under normal grid operation;

[0077] The relationship between line power flow and node phase angle:

[0078]

[0079] Among them, θ it ,θ jt They represent the phase angles of nodes i and j at time t under normal operation, respectively, and x l Represents the impedance of line l.

[0080] Transmission line power constraints:

[0081]

[0082] Among them, f l，max Indicates the maximum value of the transmission power of line l;

[0083] Node phase angle constraints:

[0084]

[0085] Among them, θ i，max Indicates the maximum value allowed for the power angle deviation of node i;

[0086] Flexible load resource power upper and lower limit constraints:

[0087]

[0088] Energy storage equipment related constraints:

[0089] The operation of energy storage equipment mainly depends on its state of charge. The charging and discharging process is expressed as:

[0090]

[0091] Where: Indicates the charge state of the battery energy storage station es during the period t; and is the charging and discharging power of the battery energy storage station es during the period t; x es，t is a 0-1 variable representing the battery energy storage state, 0 represents the charging state, and 1 represents the discharging state; η ch and η dis is the charging and discharging efficiency of the battery energy storage power station; C ES is the rated capacity of energy storage;

[0092] In order to achieve stable operation of the energy storage system, its state of charge is limited to a certain range:

[0093]

[0094] Where: and They are the upper and lower limits of the state of charge of the energy storage power station es;

[0095] The upper and lower limits of charging and discharging power of battery energy storage power stations:

[0096]

[0097] in, and They represent the upper and lower limits of power when the battery energy storage station es is charging and the upper and lower limits of power when it is discharging;

[0098] Climbing constraints of various types of regulation resources:

[0099]

[0100] Among them, Rp r，max , R d，max They represent the maximum climbing speed of the conventional unit r, the maximum climbing speed of the energy storage system es during the charging process, the maximum climbing speed of the energy storage system es during the discharging process, and the maximum climbing speed of the flexible load d response;

[0101] Load shedding constraints:

[0102]

[0103] In this implementation, S4 specifically includes:

[0104] The grid resilience index is expressed as the expected value of power shortage. Based on the load reduction, the expected value of power shortage is calculated using the following formula:

[0105]

[0106] Among them, p h represents the probability of scenario h occurring in the power system, and T represents the fault duration under extreme conditions. represents the load reduction of the i-th power node in the power system in time period t under the h-th scenario of the power system;

[0107] Compare the expected energy shortage value EENS with the energy requirement value EENS set If EENS < EENS set , the conditions are met, indicating that the current flexible resource configuration meets the resilience requirements, and the process ends; if EENSvEENS set , then the flexible resource configuration needs to be adjusted and return to S3;

[0108] Based on the initial value k0, increase Δk to obtain a new flexible resource allocation ratio k, and calculate the required increase in flexible resource capacity ΔC according to the Δk value f , adjust the corresponding flexible resource parameters:

[0109] k=k0+Δk;

[0110] ΔC f =C t Δ k .

[0111] The present invention proposes a flexible resource configuration and scheduling method for a new energy power system that takes resilience factors into consideration. The method takes into account power grid failure scenarios and new energy output scenarios under different extreme weather conditions, calculates resilience indicators for different scenarios by considering the DC optimal power flow optimization model of flexible resources, and then adjusts the flexible resource configuration ratio based on the comparison results between the indicators and the set values, and arranges the improvement priority according to the development costs of different flexible resources. Flexible resource configuration that takes resilience requirements into consideration is achieved, effectively improving the resilience of the power system.

[0112] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A flexible resource allocation and scheduling method for a new energy power system with comprehensive resilience factors, characterized in that: The steps include: S1. Initial power parameter setting, setting initial flexible resource configuration; S2, building a comprehensive scenario set through historical power parameters and probability models; S3. Conduct resilience assessment on the power system under the current flexible resource configuration. First, establish a flexible resource model, then establish a power system resilience assessment model, calculate the load loss under different scenarios, and the expected value of power shortage under the current flexible resource configuration ratio k; S4. Determine whether the expected value of power shortage meets the resilience requirements and adjust the proportion of flexible resource allocation.

2. According to the flexible resource allocation and scheduling method of a new energy power system with comprehensive resilience factors as described in claim 1, it is characterized in that: The S1 specifically includes: S11. Input basic parameters of power system transmission line data, traditional power source data and load data; S12. Set the expected energy shortage value EENS of the power system resilience index set ,EENS set It indicates the expected value of load loss allowed under extreme system conditions; S13. Setting an initial flexible resource configuration ratio k0, where k0 represents the ratio of the initial flexible resource capacity to the conventional power supply installed capacity.

3. According to the flexible resource allocation and scheduling method of a new energy power system with comprehensive resilience factors as described in claim 1, it is characterized in that: Each scenario h of the comprehensive scenario set G includes a power grid fault situation and a new energy output.

4. According to the flexible resource allocation and scheduling method of a new energy power system with comprehensive resilience factors as described in claim 1, it is characterized in that: The power system resilience assessment model specifically includes: The DC optimal power flow model of the power system is used as the model for evaluating the resilience of the power grid. The load reduction amount and the expected value of power shortage at each node are calculated. The objective function is: Among them, f h represents the sum of the conventional unit power generation cost, flexible load demand response cost, energy storage operation cost and load reduction cost of the power system in the hth state; n g 、n ED 、n d and n es They represent the number of conventional generators, grid nodes, flexible loads and energy storage systems in the power system; GC r，h () represents the power generation cost of the rth generator set in the power system under the hth state of the power system; CC i，h () represents the load reduction cost of the i-th power node in the power system under the h-th state of the power system; DC d，h () represents the d-th flexible load demand response cost in the power system under the h-th state; SC es，h () represents the operating cost of the es-th energy storage system in the power system under the h-th state; represents the active output of the rth generator set in the power system in time period t under the hth state of the power system; represents the load reduction amount of the i-th power node in the power system in time period t under the h-th state of the power system; represents the demand response power of the dth flexible load in the power system in time period t under the hth state of the power system; and They represent the charging and discharging power of the battery energy storage station es in the hth state of the power system during the t period; Operation constraints, power balance constraints for each node: Among them, the set EL represents the set of branches connected to node i; PD i，t represents the load power of node i in period t under normal grid operation, f lt It represents the power flow of line l at time t under normal grid operation; The relationship between line power flow and node phase angle: Among them, θ it ,θ jt They represent the phase angles of nodes i and j at time t under normal operation, respectively, and x l represents the impedance of line l; Transmission line power constraints: Among them, f l，max Indicates the maximum value of the transmission power of line l; Node phase angle constraints: Among them, θ i，max Indicates the maximum value allowed for the power angle deviation of node i; Flexible load resource power upper and lower limit constraints: Energy storage equipment related constraints: The operation of energy storage equipment mainly depends on its state of charge. The charging and discharging process is expressed as: Where: Indicates the charge state of the battery energy storage station es during the period t; and is the charging and discharging power of the battery energy storage station es during the period t; x es，t is a 0-1 variable representing the battery energy storage state, 0 represents the charging state, and 1 represents the discharging state; η ch and η dis is the charging and discharging efficiency of the battery energy storage power station; C ES is the rated capacity of energy storage; In order to achieve stable operation of the energy storage system, its state of charge is limited to a certain range: Where: and They are the upper and lower limits of the state of charge of the energy storage power station es; The upper and lower limits of charging and discharging power of battery energy storage power stations: in, and They represent the upper and lower limits of power when the battery energy storage station es is charging and the upper and lower limits of power when it is discharging; Climbing constraints of various types of regulation resources: Among them, Rp r，max , R d，max They represent the maximum climbing speed of the conventional unit r, the maximum climbing speed of the energy storage system es during the charging process, the maximum climbing speed of the energy storage system es during the discharging process, and the maximum climbing speed of the flexible load d response; Load shedding constraints:

5. According to the flexible resource allocation and scheduling method of a new energy power system with comprehensive resilience factors as described in claim 1, it is characterized in that: The S4 specifically includes: The grid resilience index is expressed as the expected value of power shortage. Based on the load reduction, the expected value of power shortage is calculated using the following formula: Among them, p h represents the probability of scenario h occurring in the power system, T represents the fault duration under extreme conditions, represents the load reduction of the i-th power node in the power system in time period t under the h-th scenario of the power system; Compare the expected energy shortage value EENS with the energy requirement value EENS set If EENS < EENS set , if the conditions are met, it means that the current flexible resource configuration meets the resilience requirements, and the process ends; if EENS>EENS set , then the flexible resource configuration needs to be adjusted and return to S3; Based on the initial value k0, increase Δk to obtain a new flexible resource allocation ratio k, and calculate the required increase in flexible resource capacity ΔC according to the Δk value f , adjust the corresponding flexible resource parameters: k=k0+Δk; ΔC f =C t Δk。

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