Urban power grid unbalanced power fluctuation range analysis method based on power grid flexibility

Abstract

The invention discloses an urban power grid unbalanced power fluctuation range analysis method based on power grid flexibility, relates to the field of power analysis, and solves the problem that the influence caused by urban power grid unbalanced power fluctuation cannot be effectively analyzed. Comprising the steps of calculating a real-time phase difference between real-time current and real-time voltage of a load end in a regional power grid according to a real-time current signal and a real-time voltage signal, analyzing a real-time power fluctuation range in the regional power grid according to the real-time phase difference, and analyzing the frequency of the load end in the regional power grid. The method comprises the steps of obtaining frequency change duration of a load end when a regional power grid is in an unbalanced state, analyzing voltage of the load end in the regional power grid, comprehensively analyzing the regional power grid according to a real-time active power fluctuation value and a real-time reactive power fluctuation value, and obtaining power imbalance data of the load end when the regional power grid is in the unbalanced state. According to the method, the influence caused by the unbalanced power fluctuation of the urban power grid is effectively analyzed.

Description

Technical Field

[0001] The present invention belongs to the technical field of power analysis, and in particular is a method for analyzing the unbalanced power fluctuation range of an urban power grid based on the flexibility of the power grid. Background Art

[0002] Power balance in the power grid refers to the dynamic balance between the generated power and the load power (including active power and reactive power) within the system. Unbalanced power fluctuation refers to the power imbalance within the system caused by instantaneous changes in power generation or load, which in turn causes fluctuations in parameters such as voltage and frequency. Specifically, active power imbalance directly affects the grid frequency (for example, when the generated power is less than the load power, the frequency decreases); reactive power imbalance mainly affects the grid voltage (for example, when the reactive power is insufficient, the voltage decreases); Existing technologies typically assess the probability of occurrence of unbalanced power fluctuations in urban power grids. However, when the probability assessment of unbalanced power fluctuations in urban power grids is inconsistent with reality, the existing technologies lack further analysis of the impact of active power fluctuations and reactive power fluctuations on urban power grid imbalances (e.g., changes in grid frequency and voltage). To this end, the present invention proposes a method for analyzing the unbalanced power fluctuation range of an urban power grid based on the flexibility of the power grid. Summary of the Invention

[0003] The purpose of the present invention is to propose a method for analyzing the unbalanced power fluctuation range of urban power grids based on grid flexibility, so as to solve the problem in the above background technology that it is impossible to effectively analyze the impact of unbalanced power fluctuations in urban power grids.

[0004] The purpose of the present invention can be achieved through the following technical solutions: The method for analyzing the unbalanced power fluctuation range of urban power grids based on grid flexibility includes: Step S1, calculating a real-time phase difference between a real-time current and a real-time voltage at a load end in a regional power grid based on a real-time current signal and a real-time voltage signal; Step S2, analyzing the real-time power fluctuation range in the regional power grid based on the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid; Step S3, analyzing the frequency of the load end in the regional power grid to obtain the duration of the frequency change at the load end when the regional power grid is in an unbalanced state; Step S4, analyzing the voltage at the load end of the regional power grid to obtain a voltage change at the load end when the regional power grid is in an unbalanced state; Step S5: performing a comprehensive analysis on the regional power grid based on the real-time active power fluctuation value and the real-time reactive power fluctuation value, and obtaining power imbalance data at the load end when the regional power grid is in an unbalanced state.

[0005] Furthermore, the calculation process in step S1 includes the following sub-steps: Step S11, collecting real-time current signals and real-time voltage signals at the load end of the regional power grid; Step S12, obtaining an initial phase corresponding to a real-time current signal and an initial phase corresponding to a real-time voltage signal at a load end in a regional power grid; Step S13, obtaining the real-time frequency corresponding to the real-time current signal at the load end of the regional power grid; Step S14, taking the inverse of the real-time frequency corresponding to the real-time current signal at the load end of the regional power grid to obtain the current period, and taking the inverse of the real-time frequency corresponding to the real-time voltage signal at the load end of the regional power grid to obtain the voltage period; Step S15 , subtracting the initial phase corresponding to the real-time voltage signal from the initial phase corresponding to the real-time current signal at the load end in the regional power grid to obtain a real-time phase difference XWC between the real-time current and the real-time voltage at the load end in the regional power grid.

[0006] Furthermore, the calculation process in step S2 includes: Step S21, traversing and comparing the current values ​​of the real-time current signal at the load end in a regional power grid within a single current cycle to obtain the current peak value of the real-time current signal within the single current cycle; Similarly, the voltage values ​​of the real-time voltage signal at the load end of the regional power grid within a single voltage cycle are traversed and compared to obtain the voltage peak value of the real-time voltage signal within the single voltage cycle; Step S22: Divide the peak current by To obtain the effective current I at the load end of the regional power grid, divide the peak voltage by Get the effective voltage U at the load end of the regional power grid; Step S23 , calculating the real-time active power PYG at the load end of the regional power grid by the formula PYG=U×I×cos(XWC), and calculating the real-time reactive power PWG at the load end of the regional power grid by the formula PWG=U×I×sin(XWC); Step S24, by formula The real-time load power PFH at the load end of the regional power grid is calculated.

[0007] Furthermore, the calculation process in step S2 further includes: Step S25: Repeat step S1 to obtain the real-time phase difference between the real-time current and the real-time voltage at the power supply end in the regional power grid, then repeat steps S21 to S23 to obtain the real-time active power PYG1 and real-time reactive power PWG1 at the power supply end in the regional power grid, and then calculate the real-time power supply at the power supply end in the regional power grid using the formula in step S24; Step S26, subtracting the real-time load power at the load end from the real-time power supply power at the power supply end in the regional power grid and taking the absolute value to obtain the real-time power difference of the regional power grid at the current time node; The real-time power fluctuation range of the regional power grid is obtained by traversing and comparing the real-time power differences of all time nodes to obtain the maximum value of the real-time power difference. Zero is used as the left endpoint and the maximum value of the real-time power difference is used as the right endpoint. Step S27, comparing the real-time power fluctuation range of the regional power grid with the standard power fluctuation range; If the real-time power fluctuation range of the regional power grid falls within the standard power fluctuation range, no operation will be performed; If the real-time power fluctuation range of the regional power grid does not fall within the standard power fluctuation range, the current state of the regional power grid is defined as an unbalanced state and proceeds to the next step.

[0008] Furthermore, the analysis process in step S3 is as follows: Step S31, obtaining the real-time active power of the power supply end and the real-time active power of the load end in the regional power grid; Step S32, subtracting the real-time active power of the load end from the real-time active power of the power supply end in the regional power grid to obtain the real-time active power fluctuation value ΔPYG of the regional power grid; Step S33, collecting power supply data of the power supply end in the regional power grid; Step S34, by formula The total kinetic energy ZDN at the power supply end of the regional power grid is calculated.

[0009] Furthermore, the power supply data includes the inertia constant Hm of different power supply units at the power supply end in the regional power grid and the rated capacity Sm of different power supply units, where m=1, 2, ... j, j is a positive integer, and m is the number of the power supply unit.

[0010] Furthermore, the analysis process in step S3 is as follows: Step S35: summing the rated capacities of different power supply units to obtain the system reference capacity XTJ, and dividing the total kinetic energy by the system reference capacity to obtain the system inertia constant H of the power supply end in the regional power grid; Step S36, obtaining a standard frequency f corresponding to the real-time current signal at the load end of the regional power grid; Step S37, calculating the frequency change rate PLB at the load end of the regional power grid by the formula PLB=|△PYG|×f / (2H×XTJ); Step S38 , dividing the frequency change threshold at the load end in the regional power grid by the frequency change rate to obtain the frequency change duration at the load end when the regional power grid is in an unbalanced state.

[0011] Furthermore, the analysis process in step S4 includes the following sub-steps: Step S41, obtaining the real-time reactive power PWG1 of the power supply end and the real-time reactive power PWG of the load end in the regional power grid; Step S42, subtracting the real-time reactive power at the load end from the real-time reactive power at the power supply end in the regional power grid to obtain the real-time reactive power fluctuation value ΔPWG of the regional power grid; Step S43, by formula X=PWG×U 2 / PFH 2 The reactance X of the regional power grid is calculated, and U is the effective voltage at the load end of the regional power grid; Step S44, obtaining the rated voltage UED of the load end in the regional power grid; Step S45 , calculating the voltage variation DYB at the load end of the regional power grid using the formula DYB≈X×ΔPWG / UED.

[0012] Furthermore, the analysis process in step S5 includes: Step S51, comparing the real-time active power fluctuation value of the regional power grid with the active power fluctuation range, and comparing the real-time reactive power fluctuation value of the regional power grid with the reactive power fluctuation range; Step S52: If the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range and the real-time reactive power fluctuation value of the regional power grid falls within the reactive power fluctuation range, then the regional power grid is repaired; Step S53: If the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range or the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, power imbalance data is acquired and the regional power grid is intelligently adjusted.

[0013] Furthermore, the intelligent adjustment process in step S53 includes: When the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range, the real-time active power of the power supply end in the regional power grid is adjusted within the frequency change duration until the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range; When the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, the real-time reactive power of the power supply end in the regional power grid is adjusted until the voltage variation falls within the voltage variation range; When the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range and the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, the real-time active power and the real-time reactive power of the power supply end in the regional power grid are adjusted simultaneously within the frequency change duration until the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range and the voltage change falls within the voltage change interval; The power imbalance data refers to the frequency change duration and voltage change at the load end when the regional power grid is in an unbalanced state.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention first calculates the real-time phase difference between the real-time current and real-time voltage at the load end of the regional power grid based on the real-time current signal and the real-time voltage signal. Then, the real-time power fluctuation range in the regional power grid is analyzed based on the real-time phase difference between the real-time current and real-time voltage at the load end of the regional power grid. The present invention realizes the analysis of the balance state of the regional power grid. 2. The present invention also analyzes the frequency of the load end in the regional power grid to obtain the frequency change duration of the load end when the regional power grid is in an unbalanced state. At the same time, the voltage of the load end in the regional power grid is analyzed. Then, a comprehensive analysis of the regional power grid is performed based on the real-time active power fluctuation value and the real-time reactive power fluctuation value to obtain the power imbalance data of the load end when the regional power grid is in an unbalanced state. The present invention realizes an effective analysis of the impact of unbalanced power fluctuations in urban power grids. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0016] Figure 1 is a flow chart of the method of the present invention; Figure 2 Schematic diagram of real-time current signal and real-time voltage signal in the present invention; Figure 3 This is a flow chart of the sub-steps of step S3 of the present invention; Figure 4 It is a structural schematic diagram of the electronic device in the present invention. DETAILED DESCRIPTION

[0017] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] Example 1: Please refer to Figure 1-Figure 3 As shown, the technical solution provided by the present invention is: a method for analyzing the unbalanced power fluctuation range of urban power grids based on power grid flexibility. The method is applicable to regional power grids within cities. The method is specifically as follows: In this embodiment, the regional power grid has a power supply end and a load end. For example, the power supply end is composed of different power supply units, and the load end is the power consumption end such as factories, residential houses and shopping malls connected to the regional power grid; Step S1, calculating a real-time phase difference between a real-time current and a real-time voltage at a load end in a regional power grid based on a real-time current signal and a real-time voltage signal; In this embodiment, the calculation process in step S1 includes the following sub-steps: Step S11, collecting real-time current signals and real-time voltage signals at the load end of the regional power grid; Step S12, obtaining an initial phase corresponding to a real-time current signal and an initial phase corresponding to a real-time voltage signal at a load end in a regional power grid; For example, see Figure 2 As shown, the real-time current signal is cos(2π×50×t+XW0), and the real-time current signal is cos(2π×50×t+XW1). Figure 2 As shown, w is the angular frequency, t is the time, and w is equal to 2π×50. Then the initial phase corresponding to the real-time current signal is XW0, and the initial phase corresponding to the real-time voltage signal is XW1; Step S13, obtaining the real-time frequency corresponding to the real-time current signal at the load end of the regional power grid; It should be explained that the real-time frequency corresponding to the real-time current signal and the real-time voltage signal at the load end in the regional power grid is the same; Step S14, taking the inverse of the real-time frequency corresponding to the real-time current signal at the load end of the regional power grid to obtain the current period, and taking the inverse of the real-time frequency corresponding to the real-time voltage signal at the load end of the regional power grid to obtain the voltage period; Step S15 , subtracting the initial phase corresponding to the real-time voltage signal from the initial phase corresponding to the real-time current signal at the load end in the regional power grid to obtain a real-time phase difference XWC between the real-time current and the real-time voltage at the load end in the regional power grid.

[0019] Step S2, analyzing the real-time power fluctuation range in the regional power grid based on the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid; Specifically, the calculation process in step S2 is as follows: Step S21, traversing and comparing the current values ​​of the real-time current signal at the load end in a regional power grid within a single current cycle to obtain the current peak value of the real-time current signal within the single current cycle; Similarly, the voltage values ​​of the real-time voltage signal at the load end of the regional power grid within a single voltage cycle are traversed and compared to obtain the voltage peak value of the real-time voltage signal within the single voltage cycle; It should be explained that the voltage period and the current period have the same value; Step S22: Divide the peak current by To obtain the effective current I at the load end of the regional power grid, divide the peak voltage by Get the effective voltage U at the load end of the regional power grid; Step S23 , calculating the real-time active power PYG at the load end of the regional power grid by the formula PYG=U×I×cos(XWC), and calculating the real-time reactive power PWG at the load end of the regional power grid by the formula PWG=U×I×sin(XWC); Step S24, by formula Calculate the real-time load power PFH at the load end of the regional power grid; Step S25: Repeat step S1 to obtain the real-time phase difference between the real-time current and the real-time voltage at the power supply end in the regional power grid, then repeat steps S21 to S23 to obtain the real-time active power PYG1 and real-time reactive power PWG1 at the power supply end in the regional power grid, and then calculate the real-time power supply at the power supply end in the regional power grid using the formula in step S24; Step S26, subtracting the real-time load power at the load end from the real-time power supply power at the power supply end in the regional power grid and taking the absolute value to obtain the real-time power difference of the regional power grid at the current time node; The real-time power fluctuation range of the regional power grid is obtained by traversing and comparing the real-time power differences of all time nodes to obtain the maximum value of the real-time power difference. Zero is used as the left endpoint and the maximum value of the real-time power difference is used as the right endpoint. Step S27, comparing the real-time power fluctuation range of the regional power grid with the standard power fluctuation range; If the real-time power fluctuation range of the regional power grid falls within the standard power fluctuation range, no operation will be performed; If the real-time power fluctuation range of the regional power grid does not fall within the standard power fluctuation range, the current state of the regional power grid is defined as an unbalanced state and proceed to the next step; It should be explained that the standard power fluctuation range can be determined based on the loss rate or historical data in the regional power grid.

[0020] Step S3, analyzing the frequency of the load end in the regional power grid to obtain the duration of the frequency change at the load end when the regional power grid is in an unbalanced state; In this embodiment, the analysis process in step S3 is as follows: Step S31, obtaining the real-time active power of the power supply end and the real-time active power of the load end in the regional power grid; Step S32, subtracting the real-time active power of the load end from the real-time active power of the power supply end in the regional power grid to obtain the real-time active power fluctuation value ΔPYG of the regional power grid; Step S33, collecting power supply data of the power supply end in the regional power grid; The power supply data includes the inertia constant Hm of different power supply units at the power supply end of the regional power grid and the rated capacity Sm of different power supply units, where m = 1, 2, ... j, where j is a positive integer and m is the number of the power supply unit; It should be noted that the power supply data of the power supply end in the regional power grid can be obtained from the factory at the power supply end, and the maximum power supply power is the maximum power supply power of the active power; Step S34, by formula Calculate the total kinetic energy ZDN at the power supply end of the regional power grid; Step S35: summing the rated capacities of different power supply units to obtain the system reference capacity XTJ, and dividing the total kinetic energy by the system reference capacity to obtain the system inertia constant H of the power supply end in the regional power grid; Step S36, obtaining a standard frequency f corresponding to the real-time current signal at the load end of the regional power grid; It should be explained that the standard frequency corresponding to the real-time current signal and the real-time voltage signal at the load end in the regional power grid is the same. In this embodiment, the standard frequency corresponding to the real-time current signal and the real-time voltage signal at the load end in the regional power grid is 50 Hz. Step S37, calculating the frequency change rate PLB at the load end of the regional power grid by the formula PLB=|△PYG|×f / (2H×XTJ); Step S38, dividing the frequency change threshold of the load end in the regional power grid by the frequency change rate to obtain the frequency change duration of the load end when the regional power grid is in an unbalanced state; For example, the frequency change threshold of the regional power grid is 0.2 Hz in this embodiment. It should be explained that the frequency change duration reflects the duration of the frequency change of the regional power grid to outside the allowable range. When the real-time active power fluctuation value of the regional power grid is greater than zero, the generator rotor speed at the power supply end will decrease, thereby causing the grid frequency to decrease. Similarly, when the real-time active power fluctuation value of the regional power grid is less than zero, the generator rotor speed will increase, thereby causing the grid frequency to increase.

[0021] Step S4, analyzing the voltage at the load end of the regional power grid to obtain a voltage change at the load end when the regional power grid is in an unbalanced state; Furthermore, the analysis process in step S4 includes the following sub-steps: Step S41, obtaining the real-time reactive power PWG1 of the power supply end and the real-time reactive power PWG of the load end in the regional power grid; Step S42, subtracting the real-time reactive power at the load end from the real-time reactive power at the power supply end in the regional power grid to obtain the real-time reactive power fluctuation value ΔPWG of the regional power grid; Step S43, by formula X=PWG×U 2 / PFH 2 The reactance X of the regional power grid is calculated, and U is the effective voltage at the load end of the regional power grid; Step S44, obtaining the rated voltage UED of the load end in the regional power grid; illustratively, the rated voltage is the actual voltage of the power grid under normal working conditions; Step S45, calculating the voltage variation DYB at the load end of the regional power grid by the formula DYB≈X×ΔPWG / UED; Specifically, when △PWG is greater than zero, the voltage change at the load end of the regional power grid is positive, which is manifested as a voltage increase; when △PWG is less than zero, the voltage change at the load end of the regional power grid is negative, which is manifested as a voltage decrease.

[0022] Step S5, performing a comprehensive analysis on the regional power grid based on the real-time active power fluctuation value and the real-time reactive power fluctuation value, and obtaining power imbalance data at the load end when the regional power grid is in an unbalanced state; The analysis process in step S5 is as follows: Step S51, comparing the real-time active power fluctuation value of the regional power grid with the active power fluctuation range, and comparing the real-time reactive power fluctuation value of the regional power grid with the reactive power fluctuation range; Step S52: If the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range and the real-time reactive power fluctuation value of the regional power grid falls within the reactive power fluctuation range, then the regional power grid is repaired; In step S53, if the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range or the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, power imbalance data is obtained and the regional power grid is intelligently adjusted. The adjustment process is specifically as follows: When the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range, the real-time active power of the power supply end in the regional power grid is adjusted within the frequency change duration until the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range; When the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, the real-time reactive power of the power supply end in the regional power grid is adjusted until the voltage variation falls within the voltage variation range; When the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range and the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, the real-time active power and the real-time reactive power of the power supply end in the regional power grid are adjusted simultaneously within the frequency change duration until the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range and the voltage change falls within the voltage change interval; Among them, the power imbalance data is the frequency change duration and voltage change amount at the load end when the regional power grid is in an unbalanced state; It should be explained that the active power fluctuation range and the reactive power fluctuation range can be determined based on the active power and reactive power loss rates in the regional power grid. For example, if the active power loss rate in the regional power grid is 5%, and the active power at the power supply end is 5000W, 5000×5%=250, then the active power fluctuation range can be defined as [-250W, 250W]. The calculation process of the reactive power fluctuation threshold is similar. The voltage variation range is the range consisting of the allowable voltage variation in the regional power grid.

[0023] In this application, if a corresponding calculation formula appears, the above calculation formula is dimensionless and its numerical calculation is performed. The weight coefficient, proportional coefficient and other coefficients in the formula are set to a result value obtained by quantifying each parameter. Regarding the size of the weight coefficient and the proportional coefficient, as long as it does not affect the proportional relationship between the parameter and the result value, it is acceptable.

[0024] Example 2: Figure 4This is a schematic diagram of the structure of an electronic device, which may include: a processor, a communications interface, a memory, and a communications bus, wherein the processor, the communications interface, and the memory communicate with each other via the communications bus. The processor may call logic instructions in the memory to execute a method for analyzing the unbalanced power fluctuation range of an urban power grid based on grid flexibility. The method includes: calculating a real-time phase difference between the real-time current and the real-time voltage at a load end in a regional power grid based on real-time current signals and real-time voltage signals; analyzing the real-time power fluctuation range in the regional power grid based on the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid; analyzing the frequency at the load end in the regional power grid to obtain the duration of the frequency change at the load end when the regional power grid is in an unbalanced state; analyzing the voltage at the load end in the regional power grid; and comprehensively analyzing the regional power grid based on real-time active power fluctuation values ​​and real-time reactive power fluctuation values ​​to obtain power imbalance data at the load end when the regional power grid is in an unbalanced state.

[0025] In addition, the logical instructions in the above-mentioned memory can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the existing technology, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0026] On the other hand, the present application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the urban power grid unbalanced power fluctuation range analysis method based on power grid flexibility provided by the above methods. The method includes: calculating the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid based on the real-time current signal and the real-time voltage signal, analyzing the real-time power fluctuation range in the regional power grid based on the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid, analyzing the frequency of the load end in the regional power grid, and analyzing the frequency change duration of the load end when the regional power grid is in an unbalanced state, analyzing the voltage of the load end in the regional power grid, and comprehensively analyzing the regional power grid based on the real-time active power fluctuation value and the real-time reactive power fluctuation value, and analyzing to obtain the power imbalance data at the load end when the regional power grid is in an unbalanced state.

[0027] On the other hand, the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the above-mentioned urban power grid unbalanced power fluctuation range analysis method based on power grid flexibility, the method comprising: calculating the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid based on the real-time current signal and the real-time voltage signal, analyzing the real-time power fluctuation range in the regional power grid based on the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid, analyzing the frequency of the load end in the regional power grid to obtain the frequency change duration of the load end when the regional power grid is in an unbalanced state, analyzing the voltage of the load end in the regional power grid, and comprehensively analyzing the regional power grid based on the real-time active power fluctuation value and the real-time reactive power fluctuation value to obtain the power imbalance data at the load end when the regional power grid is in an unbalanced state.

[0028] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0029] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for analyzing the unbalanced power fluctuation range of an urban power grid based on the flexibility of the power grid, characterized by: include: Step S1, calculating a real-time phase difference between a real-time current and a real-time voltage at a load end in a regional power grid based on a real-time current signal and a real-time voltage signal; Step S2, analyzing the real-time power fluctuation range in the regional power grid based on the real-time phase difference between the real-time current and the real-time voltage at the load end in the regional power grid; Step S3, analyzing the frequency of the load end in the regional power grid to obtain the duration of the frequency change at the load end when the regional power grid is in an unbalanced state; Step S4, analyzing the voltage at the load end of the regional power grid to obtain a voltage change at the load end when the regional power grid is in an unbalanced state; Step S5: performing a comprehensive analysis on the regional power grid based on the real-time active power fluctuation value and the real-time reactive power fluctuation value, and obtaining power imbalance data at the load end when the regional power grid is in an unbalanced state.

2. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 1 is characterized in that: The calculation process in step S1 includes the following sub-steps: Step S11, collecting real-time current signals and real-time voltage signals at the load end of the regional power grid; Step S12, obtaining an initial phase corresponding to a real-time current signal and an initial phase corresponding to a real-time voltage signal at a load end in a regional power grid; Step S13, obtaining the real-time frequency corresponding to the real-time current signal at the load end of the regional power grid; Step S14, taking the inverse of the real-time frequency corresponding to the real-time current signal at the load end of the regional power grid to obtain the current period, and taking the inverse of the real-time frequency corresponding to the real-time voltage signal at the load end of the regional power grid to obtain the voltage period; Step S15 , subtracting the initial phase corresponding to the real-time voltage signal from the initial phase corresponding to the real-time current signal at the load end in the regional power grid to obtain a real-time phase difference XWC between the real-time current and the real-time voltage at the load end in the regional power grid.

3. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 2 is characterized in that: The calculation process in step S2 includes: Step S21, traversing and comparing the current values ​​of the real-time current signal at the load end in a regional power grid within a single current cycle to obtain the current peak value of the real-time current signal within the single current cycle; Similarly, the voltage values ​​of the real-time voltage signal at the load end of the regional power grid within a single voltage cycle are traversed and compared to obtain the voltage peak value of the real-time voltage signal within the single voltage cycle; Step S22: Divide the peak current by To obtain the effective current I at the load end of the regional power grid, divide the peak voltage by Get the effective voltage U at the load end of the regional power grid; Step S23 , calculating the real-time active power PYG at the load end of the regional power grid by the formula PYG=U×I×cos(XWC), and calculating the real-time reactive power PWG at the load end of the regional power grid by the formula PWG=U×I×sin(XWC); Step S24, by formula The real-time load power PFH at the load end of the regional power grid is calculated.

4. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 3 is characterized in that: The calculation process in step S2 also includes: Step S25: Repeat step S1 to obtain the real-time phase difference between the real-time current and the real-time voltage at the power supply end in the regional power grid, then repeat steps S21 to S23 to obtain the real-time active power PYG1 and real-time reactive power PWG1 at the power supply end in the regional power grid, and then calculate the real-time power supply at the power supply end in the regional power grid using the formula in step S24; Step S26, subtracting the real-time load power at the load end from the real-time power supply power at the power supply end in the regional power grid and taking the absolute value to obtain the real-time power difference of the regional power grid at the current time node; The real-time power fluctuation range of the regional power grid is obtained by traversing and comparing the real-time power differences of all time nodes to obtain the maximum value of the real-time power difference. Zero is used as the left endpoint and the maximum value of the real-time power difference is used as the right endpoint. Step S27, comparing the real-time power fluctuation range of the regional power grid with the standard power fluctuation range; If the real-time power fluctuation range of the regional power grid falls within the standard power fluctuation range, no operation will be performed; If the real-time power fluctuation range of the regional power grid does not fall within the standard power fluctuation range, the current state of the regional power grid is defined as an unbalanced state and proceeds to the next step.

5. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 4 is characterized in that: The analysis process in step S3 is as follows: Step S31, obtaining the real-time active power of the power supply end and the real-time active power of the load end in the regional power grid; Step S32, subtracting the real-time active power of the load end from the real-time active power of the power supply end in the regional power grid to obtain the real-time active power fluctuation value ΔPYG of the regional power grid; Step S33, collecting power supply data of the power supply end in the regional power grid; Step S34, by formula The total kinetic energy ZDN at the power supply end of the regional power grid is calculated.

6. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 5 is characterized in that: The power supply data includes the inertia constant Hm of different power supply units at the power supply end of the regional power grid and the rated capacity Sm of different power supply units, where m=1, 2, ... j, j is a positive integer, and m is the number of the power supply unit.

7. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 6 is characterized in that: The analysis process in step S3 is as follows: Step S35: summing the rated capacities of different power supply units to obtain the system reference capacity XTJ, and dividing the total kinetic energy by the system reference capacity to obtain the system inertia constant H of the power supply end in the regional power grid; Step S36, obtaining a standard frequency f corresponding to the real-time current signal at the load end of the regional power grid; Step S37, calculating the frequency change rate PLB at the load end of the regional power grid by the formula PLB=|△PYG|×f / (2H×XTJ); Step S38 , dividing the frequency change threshold at the load end in the regional power grid by the frequency change rate to obtain the frequency change duration at the load end when the regional power grid is in an unbalanced state.

8. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 7 is characterized in that: The analysis process in step S4 includes the following sub-steps: Step S41, obtaining the real-time reactive power PWG1 of the power supply end and the real-time reactive power PWG of the load end in the regional power grid; Step S42, subtracting the real-time reactive power at the load end from the real-time reactive power at the power supply end in the regional power grid to obtain the real-time reactive power fluctuation value ΔPWG of the regional power grid; Step S43, by formula X=PWG×U 2 / PFH 2 The reactance X of the regional power grid is calculated, and U is the effective voltage at the load end of the regional power grid; Step S44, obtaining the rated voltage UED of the load end in the regional power grid; Step S45 , calculating the voltage variation DYB at the load end of the regional power grid using the formula DYB≈X×ΔPWG / UED.

9. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 8 is characterized in that: The analysis process in step S5 includes: Step S51, comparing the real-time active power fluctuation value of the regional power grid with the active power fluctuation range, and comparing the real-time reactive power fluctuation value of the regional power grid with the reactive power fluctuation range; Step S52: If the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range and the real-time reactive power fluctuation value of the regional power grid falls within the reactive power fluctuation range, then the regional power grid is repaired; Step S53: If the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range or the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, power imbalance data is acquired and the regional power grid is intelligently adjusted.

10. The method for analyzing the unbalanced power fluctuation range of an urban power grid based on power grid flexibility according to claim 9, characterized in that: The intelligent adjustment process in step S53 includes: When the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range, the real-time active power of the power supply end in the regional power grid is adjusted within the frequency change duration until the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range; When the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, the real-time reactive power of the power supply end in the regional power grid is adjusted until the voltage variation falls within the voltage variation range; When the real-time active power fluctuation value of the regional power grid does not fall within the active power fluctuation range and the real-time reactive power fluctuation value of the regional power grid does not fall within the reactive power fluctuation range, the real-time active power and the real-time reactive power of the power supply end in the regional power grid are adjusted simultaneously within the frequency change duration until the real-time active power fluctuation value of the regional power grid falls within the active power fluctuation range and the voltage change falls within the voltage change interval; Among them, the power imbalance data is the frequency change duration and voltage change at the load end when the regional power grid is in an unbalanced state.

Images