Energy storage emergency control method and system for improving high-proportion new energy power grid frequency space-time distribution

Abstract

The invention relates to the technical field of power system automation control, and discloses an energy storage emergency control method and system for improving high-proportion new energy power grid frequency space-time distribution, and the method comprises the steps: carrying out the partitioning processing of units with the same frequency response characteristic in a power grid, and determining the inertia center of the whole power grid and the inertia center of each partition; calculating unbalanced power distributed to each partition; establishing a power grid frequency response model, calculating frequency fluctuation conditions of the inertia center of the whole grid and the inertia center of each subarea, and determining two subareas with maximum frequency deviation; and calculating the energy storage control quantity for the time sequence of the two partitions with the maximum frequency deviation, and performing energy storage control. According to the method, a frequency response model containing a new energy unit is established to calculate frequency levels of different partitions in real time after power disturbance so as to provide charging and discharging control strategies for energy storage units in different partitions, and when power disturbance occurs, the energy storage units in different regions are utilized to charge and discharge so as to improve a power grid frequency space-time distribution phenomenon.

Description

Technical Field

[0001] The present invention relates to the technical field of power system automation control, and in particular to an energy storage emergency control method and system for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid. Background Art

[0002] Frequency stability is a key indicator for the stable operation of power systems. As the proportion of renewable energy in the power grid increases, the inertia level of the power grid decreases and is unevenly distributed. When a power disturbance occurs in the power grid, the frequency will shift significantly and there will be a spatiotemporal distribution phenomenon. This may cause the inertia center frequency to meet the constraint conditions but some nodes do not, resulting in misjudgment. Traditional frequency control methods such as machine cutting and load shedding cannot operate continuously and may cause system power imbalance. Therefore, solving the spatiotemporal distribution phenomenon of frequency caused by power disturbance in the power grid has become a key factor in solving the problem of power grid stability. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] In view of the above existing problems, the present invention is proposed. Therefore, the present invention provides an energy storage emergency control method for improving the spatiotemporal distribution of frequency in a high-proportion new energy power grid to solve the problem of spatiotemporal distribution of frequency caused by power disturbance in the power grid.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides an energy storage emergency control method for improving the spatiotemporal distribution of frequency in a high-proportion new energy power grid, comprising: partitioning units with the same frequency response characteristics in the power grid, determining the inertia center of the entire grid and the inertia center of each partition;

[0007] Based on the partition processing, calculating the unbalanced power allocated to each partition;

[0008] Establishing a grid frequency response model, calculating the frequency fluctuation of the center of inertia of the entire grid and the center of inertia of each partition based on the grid frequency response model and the unbalanced power of each partition, and determining the two partitions with the largest frequency deviation based on the center frequency of inertia of the entire grid;

[0009] Based on the frequency fluctuation, the energy storage control amount is calculated for the two partition timings with the largest frequency deviation, and energy storage control is performed.

[0010] As a preferred solution of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, determining the inertia center of the entire network includes:

[0011] Obtain the inertia M of each unit in the entire network through the power grid operation parameters i And the equivalent impedance Z between each unit ij ;

[0012] Calculate the sum of the products of the equivalent impedance and the unit inertia between all units in the whole network, and define the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between units as the inertia center of the whole network, expressed as:

[0013]

[0014] Where, i=j=1,2,…,n, n represents the total number of units in the whole network;

[0015] Determining the center of inertia of each partition includes:

[0016] Calculate the sum of the products of the equivalent impedance and the unit inertia between the units in the S partitions respectively, and select the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between the units in each partition S Defined as the center of inertia of the partition, expressed as:

[0017]

[0018] Among them, η s It represents the bus node with the smallest sum of the products of the equivalent impedance between units and the unit inertia in partition s. Sn represents the total number of units in partition s.

[0019] As a preferred solution of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, the calculation of the unbalanced power allocated to each partition includes:

[0020] After the power disturbance occurs, the equivalent impedance Z from the power disturbance point to the inertia center of each partition is obtained through the grid operation parameters. s , to calculate the unbalanced power P distributed to the center of inertia of each partition s , expressed as:

[0021]

[0022] Wherein, ΔP represents the power disturbance at the fault point.

[0023] As a preferred solution of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, the establishment of a power grid frequency response model includes:

[0024] The system inertia center frequency response transfer function G(s) is established and expressed as:

[0025]

[0026] Among them, ΔP d Indicates the system unbalanced power disturbance, that is, unbalanced power P s , Δf represents the central frequency deviation of the system inertia, H represents the equivalent inertia time constant of the system, D represents the equivalent damping coefficient of the system, s represents the frequency domain operator, k G is the mechanical power gain factor, F H is the work coefficient of the prime mover high pressure cylinder, T R is the reheat time constant, R is the primary frequency modulation droop coefficient, k df is the wind turbine rotor inertia coefficient, T ω k is the corresponding time constant of the virtual rotor inertia of the wind turbine, pf is the primary frequency modulation coefficient of the wind turbine pitch angle control, T β is the wind turbine pitch angle control response time coefficient;

[0027] Equivalent inertia time constant H of the system and equivalent damping coefficient D of the system to the inertia center of each partition, and obtain the equivalent inertia time constant H of each partition S , Equivalent damping coefficient D of each partition S , in order to establish the center frequency transfer function G of each partition s (s), expressed as:

[0028]

[0029] As a preferred solution of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, the two partitions with the largest frequency deviation are determined as follows:

[0030] Through the grid operation parameters, the parameters of the frequency response model of the thermal power unit and wind power unit at the inertia center of each partition are obtained to obtain the frequency response curve Δf of the inertia center of each partition in the period from the occurrence of the disturbance to the recovery of the frequency of each partition to ±0.5Hz. s ;

[0031] Frequency response curve Δf based on the center of inertia of each partition s , it is concluded that the area enclosed by the frequency response curve Δf1 of the inertia center of partition 1 and the frequency response curve Δf2 of the inertia center of partition 2 is the largest, so partition 1 and partition 2 are determined to be the two partitions with the largest frequency offset.

[0032] As a preferred solution of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, the following steps are performed: the parameters of the frequency response model of the thermal power unit and the wind power unit at the system inertia center are obtained to obtain the system inertia center frequency response curve Δf0 from the time when the disturbance occurs to the time when the frequency recovers to a steady state; the frequency response curve Δf of the inertia center of each partition is s is the frequency fluctuation of the inertia center of each partition, and the system inertia center frequency response curve Δf0 is the frequency fluctuation of the inertia center of the whole network;

[0033] Based on the frequency fluctuation, the energy storage control amount is calculated in the two partitions with the largest frequency deviation, and energy storage control is performed, including:

[0034] Step 1: Take the frequency response curves of the two partitions with the largest frequency offset and the frequency response curve of the system inertia center, the intersection points of Δf1 and Δf0, Δf2 and Δf0, and take every two adjacent intersection points of the frequency response curves Δf1 and Δf0 as a time period T. φ , every two adjacent intersections of the frequency response curve Δf2 and Δf0 are taken as a time period T φ , T φ =1,2,…,φ, φ、 They are Δf s1 and Δf, Δf s2 The number of time periods intersecting with Δf;

[0035] Step 2: Calculate the maximum difference between Δf1 and Δf0, Δf2 and Δf0 in the first time period with a step length of 0.1 seconds. The absolute values ​​of the maximum differences in the current step length |Δf1-Δf0| and |Δf2-Δf0| are the maximum deviations between the partition 1 and the partition 2 and the inertia center frequency in the first time period, respectively.

[0036] Step 3: Calculate the energy storage control proportional coefficient K1 and the energy storage control amount ΔP of partition 1 based on the maximum deviation between partition 1 and partition 2 and the inertia center frequency in the first period. S1 As well as the energy storage control quantity proportional coefficient K2 of partition 2 and the amount of energy storage participating in the control ΔP S2 ;

[0037] Step 4: In a time period, if the partition inertia center frequency is greater than the system inertia center frequency, the energy storage is charged ΔP in the current time period. s1 or ΔP s2 If the partition inertia center frequency is less than the system inertia center frequency, the energy storage will discharge ΔP in the current time period. s1 or ΔP s2 ;

[0038] After completing each time period of control, the frequency response curves of partitions 1, 2 and the system inertia center are re-determined, and steps 1 to 4 are repeated until the frequency of each partition is restored to a deviation of no more than ±0.5HZ from the initial frequency.

[0039] In a second aspect, the present invention provides an energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid, comprising:

[0040] Partitioning module, used to partition the units with the same frequency response characteristics in the power grid and determine the inertia center of the entire grid and the inertia center of each partition;

[0041] A calculation module, configured to calculate the unbalanced power allocated to each partition based on the partition processing;

[0042] A model building module is used to establish a power grid frequency response model, calculate the frequency fluctuation of the inertia center of the whole network and the inertia center of each partition based on the power grid frequency response model and the unbalanced power of each partition, and determine the two partitions with the largest frequency deviation based on the inertia center frequency of the whole network;

[0043] The energy storage control module is used to calculate the energy storage control amount for the two partitions with the largest frequency deviation based on the frequency fluctuation situation and perform energy storage control.

[0044] As a preferred solution of the energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, the partition module includes:

[0045] The first partitioning module is used to determine the center of inertia of the entire network, including:

[0046] Obtain the inertia M of each unit in the entire network through the power grid operation parameters i And the equivalent impedance Z between each unit ij ;

[0047] Calculate the sum of the products of the equivalent impedance and the unit inertia between all units in the whole network, and define the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between units as the inertia center of the whole network, expressed as:

[0048]

[0049] Where, i=j=1,2,…,n, n represents the total number of units in the whole network;

[0050] The second partition module is used to determine the center of inertia of each partition, including:

[0051] Calculate the sum of the products of the equivalent impedance and the unit inertia between the units in the S partitions respectively, and select the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between the units in each partition S Defined as the center of inertia of the partition, expressed as:

[0052]

[0053] Among them, η s It represents the bus node with the smallest sum of the products of the equivalent impedance between units and the unit inertia in partition s. Sn represents the total number of units in partition s.

[0054] As a preferred solution of the energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, a model building module is used to establish a power grid frequency response model, including:

[0055] The first model building module is used to establish the system inertia center frequency response transfer function G(s), which is expressed as:

[0056]

[0057] Among them, ΔP d Indicates the system unbalanced power disturbance, that is, unbalanced power P s , Δf represents the central frequency deviation of the system inertia, H represents the equivalent inertia time constant of the system, D represents the equivalent damping coefficient of the system, s represents the frequency domain operator, k G is the mechanical power gain factor, F H is the work coefficient of the prime mover high pressure cylinder, T R is the reheat time constant, R is the primary frequency modulation droop coefficient, k df is the wind turbine rotor inertia coefficient, T ω k is the corresponding time constant of the virtual rotor inertia of the wind turbine, pf is the primary frequency modulation coefficient of the wind turbine pitch angle control, T β is the wind turbine pitch angle control response time coefficient;

[0058] The second model building module is used to establish the center frequency transfer function G of each partition inertia s (s), the system equivalent inertia time constant H and the system equivalent damping coefficient D are equivalent to the inertia center of each partition to obtain the equivalent inertia time constant H of each partition S , Equivalent damping coefficient D of each partition S , in order to establish the center frequency transfer function G of each partition s (s), expressed as:

[0059]

[0060] As a preferred solution of the energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, a partition determination module is used to determine the two partitions with the largest frequency deviation, including:

[0061] Through the grid operation parameters, the parameters of the frequency response model of the thermal power unit and wind power unit at the inertia center of each partition are obtained to obtain the frequency response curve Δf of the inertia center of each partition in the period from the occurrence of the disturbance to the recovery of the frequency of each partition to ±0.5Hz. s ;

[0062] Frequency response curve Δf based on the center of inertia of each partition s , it is concluded that the area enclosed by the frequency response curve Δf1 of the inertia center of partition 1 and the frequency response curve Δf2 of the inertia center of partition 2 is the largest, so partition 1 and partition 2 are determined to be the two partitions with the largest frequency offset.

[0063] As a preferred solution of the energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to the present invention, the energy storage control module includes:

[0064] Obtain the parameters of the frequency response model of the thermal power unit and wind power unit at the center of the system inertia to obtain the system inertia center frequency response curve Δf0 from the time the disturbance occurs to the time the frequency recovers to a steady state; among them, the frequency response curve Δf of the inertia center of each partition s is the frequency fluctuation of the inertia center of each partition, and the system inertia center frequency response curve Δf0 is the frequency fluctuation of the inertia center of the whole network;

[0065] Based on the frequency fluctuation, the energy storage control amount is calculated in the two partitions with the largest frequency deviation, and energy storage control is performed, including:

[0066] Take the frequency response curves of the two partitions with the largest frequency offset and the frequency response curve of the system inertia center, the intersection points of Δf1 and Δf0, Δf2 and Δf0, and every two adjacent intersection points of the frequency response curves Δf1 and Δf0 as a time period T φ , every two adjacent intersections of the frequency response curve Δf2 and Δf0 are regarded as a time period T φ =1,2,…,φ, φ、 They are Δf s1 and Δf, Δf s2 The number of time periods intersecting with Δf;

[0067] Used to calculate Δf1 and Δf0, Δf2 and Δ in the first time period with a step size of 0.1 seconds f0, the absolute value of the maximum difference in the current step |Δf1-Δf0|, Δf2-Δf0| are the maximum deviations of partition 1 and partition 2 from the inertia center frequency in the first period respectively;

[0068] According to the maximum deviation between partition 1 and partition 2 and the inertia center frequency in the first period, calculate the energy storage control quantity proportional coefficient K1 of partition 1 and the energy storage participation control quantity ΔP S1 As well as the energy storage control quantity proportional coefficient K2 of partition 2 and the amount of energy storage participating in the control ΔP S2 ;

[0069] In a time period, if the partition inertia center frequency is greater than the system inertia center frequency, the energy storage is charged ΔP in the current time period. s1 or ΔP s2 If the partition inertia center frequency is less than the system inertia center frequency, the energy storage will discharge ΔP in the current time period. s1 or ΔP s2 ;

[0070] After completing each time period of control, recalculate the frequencies of partitions 1, 2 and the system inertia center, and repeat steps 1 to 4 until the frequency of each partition is restored to a deviation of no more than ±0.5HZ from the initial frequency.

[0071] In a third aspect, the present invention provides an electronic device, comprising:

[0072] Memory and processor;

[0073] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid are implemented.

[0074] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the energy storage emergency control method for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid.

[0075] Compared with the prior art, the present invention has the following beneficial effects: the present invention divides the power grid into zones according to the coherent frequency response characteristics to ensure that the frequency levels within the zones are similar, and takes the inertia center frequency within the zones to characterize the frequency levels of the zones; finds the zones with the most serious frequency spatiotemporal distribution phenomenon through frequency calculation for control optimization; establishes a frequency response model containing new energy units to calculate the frequency levels of different zones after power disturbance in real time to provide charging and discharging control strategies for energy storage units in different zones; due to the flexibility of energy storage unit distribution, rapidity and continuity during control, when power disturbance occurs, energy storage units in different regions are used for charging and discharging to improve the spatiotemporal distribution of power grid frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0077] Figure 1 It is a schematic diagram of the overall process of an energy storage emergency control method for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid according to an embodiment of the present invention;

[0078] Figure 2 A schematic diagram of a frequency response model of an energy storage emergency control method for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid according to an embodiment of the present invention;

[0079] Figure 3 A schematic diagram of a frequency situation without control measures of an energy storage emergency control method for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid according to an embodiment of the present invention;

[0080] Figure 4 A schematic diagram of the frequency condition after control of an energy storage emergency control method for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid according to an embodiment of the present invention. DETAILED DESCRIPTION

[0081] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0082] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0083] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0084] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0085] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0086] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0087] Example 1

[0088] Reference Figure 1-Figure 2 , which is an embodiment of the present invention, provides an energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid, such as Figure 1 As shown, including:

[0089] S101, dividing the units with the same frequency response characteristics in the power grid into zones, and determining the inertia center of the entire grid and the inertia center of each zone.

[0090] Specifically, partition processing includes:

[0091] The synchronous machines and network nodes with the same frequency modulation dynamic response characteristics in the power grid are divided into a partition to obtain S partitions, where S = 1, 2, ... s, and s represents the total number of partitions obtained by dividing the synchronous machines and network nodes with the same frequency modulation dynamic response characteristics.

[0092] Preferably, determining the center of inertia of the entire network includes:

[0093] Obtain the inertia M of each unit in the entire network through the power grid operation parameters i And the equivalent impedance Z between each unit ij ;

[0094] Calculate the sum of the products of the equivalent impedance and the unit inertia between all units in the whole network, and define the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between units as the inertia center of the whole network, expressed as:

[0095]

[0096] Among them, i=j=1,2,…,n, and n represents the total number of units in the entire network.

[0097] Preferably, determining the center of inertia of each partition includes:

[0098] Calculate the sum of the products of the equivalent impedance and the unit inertia between the units in the S partitions respectively, and select the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between the units in each partition s Defined as the center of inertia of the partition, expressed as:

[0099]

[0100] Among them, η s It represents the bus node with the smallest sum of the products of the equivalent impedance between units and the unit inertia in partition s. Sn represents the total number of units in partition s.

[0101] It should be noted that this step helps to identify the natural division points in the power grid and to make reasonable partitions according to the frequency response characteristics of the units. Units with the same characteristics behave similarly when responding to frequency changes, which can improve the effectiveness of the control strategy. The inertia center reflects the system's ability to resist frequency changes. Clarifying the location of these centers can help dispatchers understand the overall stability of the power grid and provide a basis for subsequent unbalanced power distribution.

[0102] S102, calculating the unbalanced power allocated to each partition based on the partition processing;

[0103] Preferably, after a power disturbance occurs, the equivalent impedance Z from the power disturbance point to the inertia center of each partition is obtained through the grid operation parameters. s, to calculate the unbalanced power P distributed to the center of inertia of each partition s , expressed as:

[0104]

[0105] Wherein, ΔP represents the power disturbance at the fault point.

[0106] It should be noted that the purpose of calculating unbalanced power is to find out where in the region the power generation needs to be increased or decreased to maintain the balance of the system, which helps to accurately adjust the power generation plan of each region and avoid frequency fluctuations caused by excess or insufficient power.

[0107] S103, establishing a grid frequency response model, and based on the grid frequency response model and the unbalanced power of each partition, calculating the frequency fluctuation of the inertia center of the entire grid and the inertia center of each partition, and determining the two partitions with the largest frequency deviation based on the inertia center frequency of the entire grid.

[0108] like Figure 2 , by establishing the system inertia center frequency response transfer function and each partition inertia center frequency transfer function, a frequency response model containing new energy units is established, including:

[0109] The system inertia center frequency response transfer function G(s) is established and expressed as:

[0110]

[0111] Among them, ΔP d Indicates the system unbalanced power disturbance, that is, unbalanced power P s , Δf represents the central frequency deviation of the system inertia, H represents the equivalent inertia time constant of the system, D represents the equivalent damping coefficient of the system, s represents the frequency domain operator, k G is the mechanical power gain factor, F H is the work coefficient of the prime mover high pressure cylinder, T R is the reheat time constant, R is the primary frequency modulation droop coefficient, k df is the wind turbine rotor inertia coefficient, T ω k is the corresponding time constant of the virtual rotor inertia of the wind turbine, pf is the primary frequency modulation coefficient of the wind turbine pitch angle control, T β is the wind turbine pitch angle control response time coefficient;

[0112] Equivalent inertia time constant H of the system and equivalent damping coefficient D of the system to the inertia center of each partition, and obtain the equivalent inertia time constant H of each partition S , Equivalent damping coefficient D of each partition S , in order to establish the center frequency transfer function G of each partition s(s), expressed as:

[0113]

[0114] Exemplarily, the frequency regulation active power variation ratio of the thermal power unit is expressed as:

[0115]

[0116] The total power change of wind turbines participating in frequency regulation is expressed as:

[0117] ΔP wind =ΔP ω +ΔP β

[0118] The power variation of wind turbine inertia response control is expressed as:

[0119]

[0120] The wind turbine pitch angle control power variation is expressed as:

[0121]

[0122] Preferably, determining the two partitions with the largest frequency offsets includes:

[0123] Through the grid operation parameters, the parameters of the frequency response model of the thermal power unit and wind turbine unit at the system inertia center and the inertia center of each partition are obtained. Through MATLAB / Simulink software, the frequency response curve Δf of the inertia center of each partition in the period from the occurrence of disturbance to the recovery of the frequency of each partition to ±0.5Hz is obtained. s ;

[0124] Frequency response curve Δf based on the center of inertia of each partition s , it is concluded that the area enclosed by the frequency response curve Δf1 of the inertia center of partition 1 and the frequency response curve Δf2 of the inertia center of partition 2 is the largest, so partition 1 and partition 2 are determined to be the two partitions with the largest frequency deviation.

[0125] It should be noted that by establishing a frequency response model containing new energy units, the frequency levels of different partitions after power disturbances are calculated in real time, and charging and discharging control strategies for energy storage units in different partitions are given to improve the spatiotemporal distribution of grid frequency.

[0126] S104, based on the frequency fluctuation, calculating the energy storage control amount for the two partitions with the largest frequency deviation, and performing energy storage control.

[0127] Preferably, the parameters of the frequency response model of the thermal power unit and the wind power unit at the system inertia center are obtained to obtain the system inertia center frequency response curve Δf0 from when the disturbance occurs to when the frequency recovers to a steady state, and then energy storage control is performed, including:

[0128] Step 1: Take the frequency response curves of the two partitions with the largest frequency offset and the frequency response curve of the system inertia center, the intersection points of Δf1 and Δf0, Δf2 and Δf0, and take every two adjacent intersection points of the frequency response curves Δf1 and Δf0 as a time period T. φ , every two adjacent intersections of the frequency response curve Δf2 and Δf0 are regarded as a time period T φ =1,2,…,φ, φ、 They are Δf s1 and Δf, Δf s2 The number of time periods intersecting with Δf;

[0129] Step 2: Calculate the maximum difference between Δf1 and Δf0, Δf2 and Δf0 in the first time period with a step length of 0.1 seconds. The absolute values ​​of the maximum differences in the current step length |Δf1-Δf0| and |Δf2-Δf0| are the maximum deviations between the partition 1 and the partition 2 and the inertia center frequency in the first time period, respectively.

[0130] Step 3: Calculate the energy storage control proportional coefficient K1 and the energy storage control amount ΔP of partition 1 based on the maximum deviation between partition 1 and partition 2 and the inertia center frequency in the first period. S1 As well as the energy storage control quantity proportional coefficient K2 of partition 2 and the amount of energy storage participating in the control ΔP S2 , expressed as:

[0131]

[0132] Where Δf 1max , Δf 1max are the maximum frequency deviations of the inertia centers of the two partitions after the power disturbance, ΔP1 and ΔP2 are the unbalanced powers allocated to the inertia centers of the two partitions, respectively;

[0133] ΔP S1 =K1|Δf1-Δf0|

[0134] ΔP S2 =K2|Δf2-Δf0|

[0135] Step 4: In a time period, if the partition inertia center frequency is greater than the system inertia center frequency, the energy storage is charged ΔP in the current time period. s1 or ΔP s2If the partition inertia center frequency is less than the system inertia center frequency, the energy storage will discharge ΔP in the current time period. s1 or ΔP s2 ;

[0136] After completing each time period of control, re-determine the frequencies of partitions 1, 2 and the system inertia center, and repeat steps 1 to 4 until the frequencies of each partition are restored to a deviation of no more than ±0.5HZ from the initial frequency.

[0137] It should be noted that the present invention divides the power grid into zones according to the coherent frequency response characteristics to ensure that the frequency levels within the zones are similar, and the inertia center frequency within the zones is used to characterize the frequency levels of the zones. Through frequency calculation, the zones with the most serious frequency spatiotemporal distribution phenomenon are found for control optimization; traditional frequency control methods such as cutting the machine and the load cannot operate continuously and may cause system power imbalance. Due to the flexibility of the distribution of energy storage units, the rapidity and continuity of control, when power disturbance occurs, the energy storage units in different regions are used to charge and discharge to improve the frequency spatiotemporal distribution phenomenon of the power grid.

[0138] The above is a schematic scheme of an energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy grid in this embodiment. It should be noted that the technical solution of the energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy grid and the technical solution of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy grid mentioned above belong to the same concept. The details not described in detail in the technical solution of the energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy grid in this embodiment can all be referred to the description of the technical solution of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy grid mentioned above.

[0139] In this embodiment, the energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid includes:

[0140] Partitioning module, used to partition the units with the same frequency response characteristics in the power grid and determine the inertia center of the entire grid and the inertia center of each partition;

[0141] A calculation module, used for calculating the unbalanced power allocated to each partition based on partition processing;

[0142] The model building module is used to establish a grid frequency response model. Based on the grid frequency response model and the unbalanced power of each partition, the frequency fluctuation of the inertia center of the entire grid and the inertia center of each partition is calculated, and the two partitions with the largest frequency deviation are determined based on the inertia center frequency of the entire grid;

[0143] The energy storage control module is used to calculate the energy storage control amount for the two partitions with the largest frequency deviation based on the frequency fluctuation situation and perform energy storage control.

[0144] Preferably, the partition module includes:

[0145] The first partition module is used to determine the center of inertia of the entire network, including:

[0146] Obtain the inertia M of each unit in the entire network through the power grid operation parameters i And the equivalent impedance Z between each unit ij ;

[0147] Calculate the sum of the products of the equivalent impedance and the unit inertia between all units in the whole network, and define the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between units as the inertia center of the whole network, expressed as:

[0148]

[0149] Where, i=j=1,2,…,n, n represents the total number of units in the whole network;

[0150] The second partition module is used to determine the center of inertia of each partition, including:

[0151] Calculate the sum of the products of the equivalent impedance and the unit inertia between the units in the S partitions respectively, and select the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between the units in each partition S Defined as the center of inertia of the partition, expressed as:

[0152]

[0153] Among them, η s It represents the bus node with the smallest sum of the products of the equivalent impedance between units and the unit inertia in partition s. Sn represents the total number of units in partition s.

[0154] Preferably, the model building module is used to establish a power grid frequency response model, including:

[0155] The first model building module is used to establish the system inertia center frequency response transfer function G(s), which is expressed as:

[0156]

[0157] Among them, ΔP d Indicates the system unbalanced power disturbance, that is, unbalanced power P s , Δf represents the central frequency deviation of the system inertia, H represents the equivalent inertia time constant of the system, D represents the equivalent damping coefficient of the system, s represents the frequency domain operator, k G is the mechanical power gain factor, F H is the work coefficient of the prime mover high pressure cylinder, T R is the reheat time constant, R is the primary frequency modulation droop coefficient, k dfis the wind turbine rotor inertia coefficient, T ω k is the corresponding time constant of the virtual rotor inertia of the wind turbine, pf is the primary frequency modulation coefficient of the wind turbine pitch angle control, T β is the wind turbine pitch angle control response time coefficient;

[0158] The second model building module is used to establish the center frequency transfer function G of each partition inertia s (s), the system equivalent inertia time constant H and the system equivalent damping coefficient D are equivalent to the inertia center of each partition to obtain the equivalent inertia time constant H of each partition S , Equivalent damping coefficient D of each partition S , in order to establish the center frequency transfer function G of each partition s (s), expressed as:

[0159]

[0160] The partition determination module is used to determine the two partitions with the largest frequency offset, including:

[0161] Through the grid operation parameters, the parameters of the frequency response model of the thermal power unit and wind power unit at the inertia center of each partition are obtained to obtain the frequency response curve Δf of the inertia center of each partition in the period from the occurrence of the disturbance to the recovery of the frequency of each partition to ±0.5Hz. s ;

[0162] Frequency response curve Δf based on the center of inertia of each partition s , it is concluded that the area enclosed by the frequency response curve Δf1 of the inertia center of partition 1 and the frequency response curve Δf2 of the inertia center of partition 2 is the largest, so partition 1 and partition 2 are determined to be the two partitions with the largest frequency offset.

[0163] Preferably, the energy storage control module includes:

[0164] Obtain the parameters of the frequency response model of the thermal power unit and wind power unit at the center of the system inertia to obtain the system inertia center frequency response curve Δf0 from the time the disturbance occurs to the time the frequency recovers to a steady state; among them, the frequency response curve Δf of the inertia center of each partition s is the frequency fluctuation of the inertia center of each partition, and the system inertia center frequency response curve Δf0 is the frequency fluctuation of the inertia center of the whole network;

[0165] Based on the frequency fluctuation, the energy storage control amount is calculated in the two partitions with the largest frequency deviation, and energy storage control is performed, including:

[0166] Take the frequency response curves of the two partitions with the largest frequency offset and the frequency response curve of the system inertia center, the intersection points of Δf1 and Δf0, Δf2 and Δf0, and every two adjacent intersection points of the frequency response curves Δf1 and Δf0 as a time period T φ , every two adjacent intersections of the frequency response curve Δf2 and Δf0 are regarded as a time period T φ =1,2,…,φ, φ、 They are Δf s1 and Δf, Δf s2 The number of time periods intersecting with Δf;

[0167] It is used to calculate the maximum difference between Δf1 and Δf0, Δf2 and Δf0 in the first time period with a step size of 0.1 seconds. The absolute values ​​of the maximum differences in the current step size |Δf1-Δf0| and |Δf2-Δf0| are the maximum deviations of partition 1 and partition 2 from the inertia center frequency in the first time period, respectively.

[0168] According to the maximum deviation between partition 1 and partition 2 and the inertia center frequency in the first period, calculate the energy storage control quantity proportional coefficient K1 of partition 1 and the energy storage participation control quantity ΔP S1 As well as the energy storage control quantity proportional coefficient K2 of partition 2 and the amount of energy storage participating in the control ΔP S2 ;

[0169] In a time period, if the partition inertia center frequency is greater than the system inertia center frequency, the energy storage is charged ΔP in the current time period. s1 or ΔP s2 If the partition inertia center frequency is less than the system inertia center frequency, the energy storage will discharge ΔP in the current time period. s1 or ΔP s2 ;

[0170] After each time period of control is completed, the frequency response curves of partitions 1, 2 and the system inertia center are recalculated, and steps 1 to 4 are repeated until the frequency of each partition is restored to a deviation of no more than ±0.5HZ from the initial frequency.

[0171] This embodiment also provides an electronic device suitable for improving the energy storage emergency control situation of the frequency spatiotemporal distribution of a high-proportion new energy power grid, including:

[0172] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the energy storage emergency control method proposed in the above embodiment to improve the spatiotemporal distribution of the frequency of a high-proportion new energy power grid.

[0173] This embodiment also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the energy storage emergency control method proposed in the above embodiment for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid.

[0174] The storage medium proposed in this embodiment and the energy storage emergency control method proposed in the above embodiment for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0175] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0176] Example 2

[0177] Refer to Table 1-Table 4 and Figure 3-Figure 4 , which is an embodiment of the present invention, provides an energy storage emergency control method for improving the spatiotemporal distribution of frequency in a high-proportion new energy power grid. In order to verify its beneficial effects, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0178] Taking the East China power grid as an example, after the power grid is divided into zones according to the coherent frequency response characteristics, each provincial power grid is a zone. Tables 1-3 respectively show the system inertia center parameters, zone 1 parameters, and zone 2 parameter data.

[0179] Table 1: System inertia center parameters

[0180] D <![CDATA[k df ]]> <![CDATA[k pf ]]> <![CDATA[T β ]]> <![CDATA[T ω ]]> <![CDATA[k G ]]> <![CDATA[F H ]]> <![CDATA[T R ]]> R 2 8 20 3 0.01 0.95 0.3 0.01 0.05

[0181] Table 2: Partition 1 parameter table

[0182] D <![CDATA[k df ]]> <![CDATA[k pf ]]> <![CDATA[T β ]]> <![CDATA[T ω ]]> <![CDATA[k G ]]> <![CDATA[F H ]]> <![CDATA[T R ]]> R 1.9 8 22 3 0.01 0.9 0.3 0.01 0.05

[0183] Table 3: Partition 2 parameter table

[0184] D <![CDATA[k df ]]> <![CDATA[k pf ]]> <![CDATA[T β ]]> <![CDATA[T ω ]]> <![CDATA[k G ]]> <![CDATA[F H ]]> <![CDATA[T R ]]> R 1.7 7 19 3 0.01 0.95 0.3 0.01 0.05

[0185] See Table 4 and Figure 3-Figure 4 At 2 seconds, Anji-Lanjiang N-1 fails. When there is no control measure, the maximum frequency deviation between partition 1 and partition 2 reaches 0.45Hz. After the fault occurs, the control strategy is given according to the steps of the present invention, and the maximum frequency deviation between partition 1 and partition 2 is reduced to 0.15Hz. The above verification shows that the method proposed by the present invention to improve the frequency spatiotemporal distribution phenomenon after power disturbance of a high proportion of new energy power grid using energy storage units is effective.

[0186] Table 4: Control strategy for energy storage units in zones 1 and 2

[0187]

[0188]

[0189] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid by emergency energy storage control, characterized in that: include: Divide the units with the same frequency response characteristics in the power grid into zones to determine the inertia center of the entire grid and the inertia center of each zone; Based on the partition processing, calculating the unbalanced power allocated to each partition; Establishing a grid frequency response model, calculating the frequency fluctuation of the inertia center of the entire grid and the inertia center of each partition based on the grid frequency response model and the unbalanced power of each partition, and determining the two partitions with the largest frequency deviation based on the inertia center frequency of the entire grid; Based on the frequency fluctuation, the energy storage control amount is calculated for the two partition timings with the largest frequency deviation, and energy storage control is performed.

2. The energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to claim 1, characterized in that: Determining the center of inertia of the entire network and the center of inertia of each partition includes: Determining the center of inertia of the entire network includes: Obtain the inertia M of each unit in the entire network through the power grid operation parameters i And the equivalent impedance Z between each unit ij ; Calculate the sum of the products of the equivalent impedance and the unit inertia between all units in the whole network, and define the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between units as the inertia center of the whole network, expressed as: Where, i=j=1,2,…,n, n represents the total number of units in the whole network; Determining the center of inertia of each partition includes: Calculate the sum of the products of the equivalent impedance and the unit inertia between the units in the S partitions respectively, and select the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between the units in each partition S Defined as the center of inertia of the partition, expressed as: Among them, η s It represents the bus node with the smallest sum of the products of the equivalent impedance between units and the unit inertia in partition s. Sn represents the total number of units in partition s.

3. The energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid according to claim 1 or 2, characterized in that: The calculation of the unbalanced power allocated to each partition includes: After the power disturbance occurs, the equivalent impedance Z from the power disturbance point to the inertia center of each partition is obtained through the grid operation parameters. s , to calculate the unbalanced power P distributed to the center of inertia of each partition s , expressed as: Wherein, ΔP represents the power disturbance at the fault point.

4. The energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid as claimed in claim 1, characterized in that: The establishing of the power grid frequency response model comprises: The system inertia center frequency response transfer function G(s) is established and expressed as: Among them, ΔP d Indicates the system unbalanced power disturbance, that is, unbalanced power P s , Δf represents the central frequency deviation of the system inertia, H represents the equivalent inertia time constant of the system, D represents the equivalent damping coefficient of the system, s represents the frequency domain operator, k G is the mechanical power gain factor, F H is the work coefficient of the high-pressure cylinder of the prime mover, TR is the reheating time constant, R is the primary frequency modulation droop coefficient, k df is the corresponding coefficient of inertia of the wind turbine rotor, T ω k is the corresponding time constant of the virtual rotor inertia of the wind turbine, pf is the primary frequency modulation coefficient of the wind turbine pitch angle control, T β is the wind turbine pitch angle control response time coefficient; Equivalent inertia time constant H of the system and equivalent damping coefficient D of the system to the inertia center of each partition, and obtain the equivalent inertia time constant H of each partition S , Equivalent damping coefficient D of each partition S , in order to establish the center frequency transfer function G of each partition s (s), expressed as:

5. The energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid as claimed in claim 1, characterized in that: The determining of the two partitions with the largest frequency offsets comprises: Through the grid operation parameters, the parameters of the frequency response model of the thermal power unit and wind power unit at the inertia center of each partition are obtained to obtain the frequency response curve Δf of the inertia center of each partition in the period from the occurrence of the disturbance to the recovery of the frequency of each partition to ±0.5Hz. s ; Frequency response curve Δf based on the center of inertia of each partition s , it is concluded that the area enclosed by the frequency response curve Δf1 of the inertia center of partition 1 and the frequency response curve Δf2 of the inertia center of partition 2 is the largest, so partition 1 and partition 2 are determined to be the two partitions with the largest frequency offset.

6. The energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid as claimed in claim 5, characterized in that: Also includes: Obtain the parameters of the frequency response model of the thermal power unit and wind power unit at the center of the system inertia to obtain the system inertia center frequency response curve Δf0 from the time the disturbance occurs to the time the frequency recovers to a steady state; among them, the frequency response curve Δf of the inertia center of each partition s is the frequency fluctuation of the inertia center of each partition, and the system inertia center frequency response curve Δf0 is the frequency fluctuation of the inertia center of the whole network; Based on the frequency fluctuation, the energy storage control amount is calculated in the two partitions with the largest frequency deviation, and energy storage control is performed, including: Step 1: Take the frequency response curves of the two partitions with the largest frequency offset and the frequency response curve of the system inertia center, the intersection points of Δf1 and Δf0, Δf2 and Δf0, and take every two adjacent intersection points of the frequency response curves Δf1 and Δf0 as a time period T. φ , every two adjacent intersections of the frequency response curve Δf2 and Δf0 are regarded as a time period T φ =1,2,…,φ, φ、 They are Δf s1 and Δf, Δf s2 The number of time periods intersecting with Δf; Step 2: Calculate the maximum difference between Δf1 and Δf0, Δf2 and Δf0 in the first time period with a step length of 0.1 seconds. The absolute values ​​of the maximum differences in the current step length |Δf1-Δf0| and Δf2-Δf0| are the maximum deviations between the partition 1 and the partition 2 and the inertia center frequency in the first time period, respectively. Step 3: Calculate the energy storage control proportional coefficient K1 and the energy storage control amount ΔP of partition 1 based on the maximum deviation between partition 1 and partition 2 and the inertia center frequency in the first period. S1 As well as the energy storage control quantity proportional coefficient K2 of partition 2 and the amount of energy storage participating in the control ΔP S2 ; Step 4: In a time period, if the partition inertia center frequency is greater than the system inertia center frequency, the energy storage is charged ΔP in the current time period. s1 or ΔP s2 If the partition inertia center frequency is less than the system inertia center frequency, the energy storage will discharge ΔP in the current time period. s1 or ΔP s2 ; After completing each time period of control, the frequency response curves of partitions 1, 2 and the system inertia center are re-determined, and steps 1 to 4 are repeated until the frequency of each partition is restored to a deviation of no more than ±0.5HZ from the initial frequency.

7. An energy storage emergency control system for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid, characterized in that: include, Partitioning module, used to partition the units with the same frequency response characteristics in the power grid and determine the inertia center of the entire grid and the inertia center of each partition; A calculation module, configured to calculate the unbalanced power allocated to each partition based on the partition processing; A model building module is used to establish a power grid frequency response model, calculate the frequency fluctuation of the inertia center of the whole network and the inertia center of each partition based on the power grid frequency response model and the unbalanced power of each partition, and determine the two partitions with the largest frequency deviation based on the inertia center frequency of the whole network; The energy storage control module is used to calculate the energy storage control amount for the two partitions with the largest frequency deviation based on the frequency fluctuation situation and perform energy storage control.

8. The energy storage emergency control system for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid as claimed in claim 7, characterized in that: The partition module comprises: The first partitioning module is used to determine the center of inertia of the entire network, including: Obtain the inertia M of each unit in the entire network through the power grid operation parameters i And the equivalent impedance Z between each unit ij ; Calculate the sum of the products of the equivalent impedance and the unit inertia between all units in the whole network, and define the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between units as the inertia center of the whole network, expressed as: Where, i=j=1,2,…,n, n represents the total number of units in the whole network; The second partition module is used to determine the center of inertia of each partition, including: Calculate the sum of the products of the equivalent impedance and the unit inertia between the units in the S partitions respectively, and select the bus node η with the smallest sum of the products of the equivalent impedance and the unit inertia between the units in each partition S Defined as the center of inertia of the partition, expressed as: Among them, η s It represents the bus node with the smallest sum of the products of the equivalent impedance between units and the unit inertia in partition s. Sn represents the total number of units in partition s.

9. An electronic device, characterized in that: include: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the energy storage emergency control method for improving the spatiotemporal distribution of frequency of a high-proportion new energy power grid as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: It stores computer executable instructions, which, when executed by a processor, implement the steps of the energy storage emergency control method for improving the spatiotemporal distribution of the frequency of a high-proportion new energy power grid as described in any one of claims 1 to 7.

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