A cloud platform-based power grid remote control method and system

Abstract

The present application relates to the field of cloud platform power grid control technology, and specifically to a cloud platform-based power grid remote control method and system, the method comprising: collecting voltage data of the main power grid; collecting voltage data, current data, frequency data and power data of each power supply device and each power-consuming device; collecting the remaining capacity of the energy storage device; calculating the power supply stability coefficient; and then obtaining the energy storage power supply stability coefficient; calculating the power supply reliability coefficient; and then obtaining the grid connection stability; obtaining the power generation capacity index of each power supply device in each time sub-window; obtaining the off-grid stability of each power supply device in each time sub-window; calculating the power supply stability coefficient; obtaining the comprehensive weight of each power supply device in each time window based on the power supply reliability coefficient and the power supply stability coefficient; selecting the main power supply in each time window according to the comprehensive weight, and remotely controlling the power grid. The present application solves the problem of failure in microgrids leading to failure in grid connection and off-grid.

Description

Technical Field

[0001] The present application relates to the technical field of cloud platform power grid control, and in particular to a cloud platform-based power grid remote control method and system. Background Art

[0002] Cloud platform refers to cloud computing platform, which is a technology that provides computing resources, software applications, data storage and other services through the Internet. Microgrid is a small power supply network that can be connected to the main grid or run off-grid when the main grid fails. Controlling the off-grid and grid-connection process of microgrid through cloud platform can improve the operation efficiency and reliability of microgrid, thereby reducing power outage time.

[0003] The master-slave control algorithm can be used to control the off-grid and grid-connected process of the microgrid. The principle of this algorithm is to set the main power supply to maintain the voltage and frequency of the microgrid, and the master and slave power supplies operate in coordination. When connected to the grid, the main power supply tracks the voltage and frequency of the main grid; when off-grid, the main power supply maintains the stability of the microgrid, and the slave power supply outputs power according to the instructions of the main power supply. Traditional master-slave control algorithms usually select the power generation equipment with the largest output power or the energy storage equipment with the largest capacity as the main power supply, and cannot be switched. Therefore, once the main power supply fails, it will affect the off-grid and grid-connected process of the microgrid, and may even cause off-grid and grid-connected failure. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a cloud platform-based power grid remote control method and system, the technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present application provides a cloud platform-based power grid remote control method, the method comprising the following steps:

[0006] Collect voltage data of the main power grid; collect voltage data, current data, frequency data and power data of each power supply device and each power-consuming device; power supply devices include diesel generators, energy storage devices, wind turbines and solar generators, and collect the remaining capacity of energy storage devices;

[0007] Based on the difference between the voltage data of the power supply device and the preset output voltage, and the difference between the frequency data and the preset output frequency, the power supply stability coefficient of each power supply device in each time window is obtained;

[0008] Based on the remaining capacity, voltage data, and current data of the energy storage device, the energy storage power supply stability coefficient of each energy storage device in each time window is obtained;

[0009] Obtain the power reliability coefficient of each power supply device in each time window based on the power supply stability coefficient and the energy storage power supply stability coefficient;

[0010] Based on the difference between the average voltage of the power supply device and the average voltage of the main grid, and the difference between the average phase of the voltage of the power supply device and the average phase of the voltage of the main grid, the grid connection stability of each power supply device in each time subwindow is obtained;

[0011] Based on the maximum power of the power supply equipment, the remaining capacity of the energy storage equipment and the average power data of the generator, the power generation capacity index of each power supply equipment in each time sub-window is obtained;

[0012] Based on the difference between the average power data of the power supply equipment and the average power data of the power consumption equipment and the power generation capacity index, the off-grid stability of each power supply equipment in each time sub-window is obtained;

[0013] The normalized value of the ratio of off-grid stability to grid-connected stability is used as the power stability coefficient of each power supply device in each time sub-window; the comprehensive weight of each power supply device in each time window is obtained based on the power reliability coefficient and the power stability coefficient;

[0014] The main power source in each time window is selected according to the comprehensive weight, and the power grid is remotely controlled.

[0015] Furthermore, the calculation formula of the power supply stability coefficient is: ; In the formula, PSI represents the power supply stability coefficient of each power supply device in each time window; T represents the number of sampling moments in the time window, , Respectively represent the voltage data and frequency data of each power supply device at the i-th acquisition moment in each time window, , Respectively represent the preset output voltage and preset output frequency of each power supply device.

[0016] Furthermore, the calculation formula of the energy storage power supply stability coefficient is: ; In the formula, CPSI represents the energy storage power supply stability coefficient of each energy storage device in each time window, represents the remaining capacity of each energy storage device at the last acquisition moment in each time window, H represents the preset first threshold of each energy storage device, T represents the number of acquisition moments in the time window, , Respectively represent the voltage data and current data of each energy storage device at the i-th collection moment in each time window.

[0017] Furthermore, the method for obtaining the power supply reliability coefficient is:

[0018] For each power supply device in each time window, when the power supply device is a device other than an energy storage device, the value of the energy storage power supply stability coefficient is set to 0, and the normalized value of the sum of the power supply stability coefficient of each power supply device and the energy storage power supply stability coefficient is calculated, and the difference between the value 1 and the normalized value is calculated as the power supply reliability coefficient of each power supply device.

[0019] Furthermore, the method for obtaining the grid-connected stability is:

[0020] For each power supply device and the main power grid, a discrete Fourier transform is performed on the voltage signal in each time sub-window to obtain the phase information of the voltage signal at each acquisition moment;

[0021] For each time sub-window, the absolute value of the difference between the voltage average value of each power supply device and the voltage average value of the main power grid is calculated as the first absolute value of the difference, and the absolute value of the difference between the phase average value of each power supply device and the phase average value of the main power grid is calculated as the second absolute value of the difference. The product of the first absolute value of the difference and the second absolute value of the difference is taken as the grid-connected stability of each power supply in each time sub-window.

[0022] Furthermore, the method for obtaining the power generation capacity index is:

[0023] When the power supply device is a diesel generator, the maximum power of the diesel generator is used as the power generation capacity index of the power supply device in each time sub-window;

[0024] When the power supply device is an energy storage device, the remaining capacity of the energy storage device at the last acquisition moment of each time sub-window is used as the power generation capacity index of the power supply device in each time sub-window;

[0025] When the power supply device is a wind generator or a solar generator, the average value of the power data of the generator in the time sub-window is used as the power generation capacity index of the power supply device in each time sub-window.

[0026] Further, the calculation formula of the off-grid stability is: ; In the formula, OI represents the off-grid stability of each power supply device in each time sub-window; Q is the power generation capacity index of each power supply device in each time sub-window, N and M represent the number of power supply devices and the number of power consumption devices in the microgrid respectively. represents the mean value of the power data of the ith power supply device in each time sub-window, Represents the mean value of the power data of the jth electrical equipment in each time sub-window.

[0027] Further, the obtaining of the comprehensive weight of each power supply device in each time window based on the power supply reliability coefficient and the power supply stability coefficient includes:

[0028] The target layer of the hierarchical analysis method is set to select the main power supply, the criterion layer is set to the power reliability coefficient of the power supply equipment in each time window and the mean of all power stability coefficients of the power supply equipment in each time window, and the scheme layer is each power supply equipment, and the comprehensive weight of each power supply equipment in each time window is output.

[0029] Further, the method of selecting the main power source in each time window according to the comprehensive weight and remotely controlling the power grid includes:

[0030] For each time window, the power supply device with the largest comprehensive weight is used as the main power supply for each time window. The main power supply is switched once every time window. The main power supply is switched once when the operating status of the microgrid changes, and the power supply is remotely controlled.

[0031] In a second aspect, an embodiment of the present application further provides a cloud platform-based power grid remote control system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above-mentioned methods when executing the computer program.

[0032] This application has at least the following beneficial effects:

[0033] This application considers the stability of the output power of the power supply equipment and calculates the power supply stability coefficient of each power supply; further considers the decrease in capacity of the energy storage equipment as the power supply time increases, and calculates the energy storage power supply stability coefficient of the energy storage equipment; in order to consider the characteristics of different power supply equipment, the power supply reliability coefficient of the power supply equipment is obtained based on the power supply stability coefficient and the energy storage power supply stability coefficient;

[0034] In order to reflect the stability of the synchronization between the main power supply and the main power grid during the grid-connected process and the stability of the coordinated output between the main power supply and other power supply equipment during the off-grid process, the grid-connected stability and off-grid stability of each power supply equipment are calculated, and the power supply stability coefficient of each power supply equipment is obtained based on the grid-connected stability and off-grid stability; the main power supply is selected according to the power supply reliability coefficient and the power supply stability coefficient, and the defects of the fixed main power supply in the master-slave control algorithm of the microgrid are optimized to avoid the impact of the microgrid due to the failure of the main power supply, and solve the problem that the power fluctuation of the microgrid before and after the grid connection and off-grid brings impact current, causing faults in the microgrid and leading to grid connection and off-grid failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A flowchart of a cloud platform-based power grid remote control method provided in one embodiment of the present application;

[0037] Figure 2 A schematic diagram of main power switching provided by an embodiment of the present application;

[0038] Figure 3 A schematic diagram of microgrid power fluctuation provided for one embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the cloud platform-based power grid remote control method and system proposed in the present application, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0040] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0041] The following is a detailed description of a specific solution of a cloud platform-based power grid remote control method and system provided by the present application in conjunction with the accompanying drawings.

[0042] See also Figure 1 , which shows a flowchart of a cloud platform-based power grid remote control method provided by an embodiment of the present application, the method comprising the following steps:

[0043] Step S1, collecting voltage data of the main power grid; collecting voltage data, current data, frequency data and power data of each power supply device and each power-consuming device; the power supply equipment includes diesel generators, energy storage equipment, wind turbines and solar generators, and collecting the remaining capacity of the energy storage equipment.

[0044] A cloud platform-based power grid remote control method takes a factory in a remote area as an example. A microgrid system is built in the factory to ensure the electricity needs of production and life. The microgrid is connected to the main power grid, including power generation equipment such as wind turbines, solar generators and diesel generators, multiple energy storage devices and various power load equipment, such as industrial electricity and workers' living electricity equipment.

[0045] A voltage sensor is installed at the connection between the microgrid and the main grid to collect the voltage data of the main grid in real time; a voltage sensor, a current sensor, a frequency sensor and a power sensor are installed at each power supply device and power consumption device in the microgrid to collect their voltage, current, frequency and power data in real time. In this embodiment, the power source includes a diesel generator, an energy storage device, a wind generator and a solar generator.

[0046] In addition, energy storage detection sensors are installed at the energy storage devices to collect changes in the remaining capacity of the energy storage devices.

[0047] There are generally two situations for the off-grid operation of the microgrid. One is that the main grid needs to be repaired and notifies the microgrid to go off-grid actively. The other is that the main grid fails and the microgrid is forced to go off-grid. When the main grid conditions are suitable, the microgrid performs grid-connected operation and runs in parallel with the main grid. Therefore, the microgrid may need to switch the main power supply before and after the off-grid connection. In addition, if the main power supply fails or the current power supply is not efficient as the main power supply, the main power supply also needs to be switched. Therefore, the frequency of switching the main power supply is not high. All sensors collect data every s. In this embodiment, the interval between each collection time is 0.1s, and the length of each time window is h. The value of this embodiment is 1h. The implementer can select other lengths according to actual conditions.

[0048] The data is uploaded to the cloud platform, the collected data is cleaned, the missing data is interpolated and completed, and finally the data is standardized and normalized. Data cleaning, data completion, and data standardization and normalization are well-known technologies and the specific contents will not be repeated here.

[0049] Step S2, based on the difference between the voltage data of the power supply device and the preset output voltage, and the difference between the frequency data and the preset output frequency, obtain the power supply stability coefficient of each power supply device in each time window; based on the remaining capacity, voltage data, and current data of the energy storage device, obtain the energy storage power supply stability coefficient of each energy storage device in each time window; based on the power supply stability coefficient and the energy storage power supply stability coefficient, obtain the power supply reliability coefficient of each power supply device in each time window.

[0050] Microgrids can be connected to the main grid and exchange energy with the main grid. When the power generation is large, they can sell electricity to the main grid to obtain economic benefits. When the power generation is insufficient, they can purchase electricity from the main grid to meet the load demand. It can also be operated independently off the grid because it contains power generation equipment and energy storage equipment. In order to achieve remote control of microgrids based on cloud platforms, master-slave control algorithms are usually used to select the main power supply. When connected to the grid, the voltage and frequency of the main grid are tracked by the main power supply; when off-grid, the microgrid is maintained stable by the main power supply. Other power supplies act as slave power supplies and output power according to the instructions of the main power supply.

[0051] When selecting the main power source, you need to consider its reliability and stability. If it does not meet the requirements, you need to switch the main power source. Usually, you need to switch the main power source before and after the off-grid and grid-connected process or when the main power source fails during normal operation. It should be noted that in addition to power generation equipment, energy storage devices can also be used as the main power source. However, when the energy storage device is used as the main power source, the main power source needs to be switched when the stored energy is insufficient.

[0052] When selecting the main power supply in a microgrid, the stability of its output power must be considered first. That is, the more stable the output power of the power supply is, the more suitable it is as the main power supply, so that the power of the microgrid can be balanced and the occurrence of faults can be reduced. Therefore, firstly, the power supply stability coefficient of each power supply in each time window is calculated based on the difference between the power supply output and the reference output. The calculation formula is: ; In the formula, PSI represents the power supply stability coefficient of each power supply device in each time window; T represents the number of sampling moments in the time window, , Respectively represent the voltage data and frequency data of each power supply device at the i-th acquisition moment in each time window, , They respectively represent the preset output voltage and preset output frequency of each power supply device; in this embodiment, the preset output voltage of each power supply is 380V, and the preset output frequency is 50Hz.

[0053] For the main power supply, it should be able to provide stable voltage and frequency to ensure that various loads in the microgrid can operate normally. When its output fluctuation increases, other power supplies should be switched to become the main power supply in time to avoid power imbalance in the microgrid.

[0054] The smaller the value of the power supply stability coefficient, the closer the output voltage and frequency of the current power supply are to the reference voltage and frequency, that is, the smaller the output fluctuation, the higher the power supply stability, and the more suitable it is to be the main power supply; on the contrary, it means that the output fluctuation is large, and it is less suitable to be the main power supply.

[0055] The power supply stability coefficient only considers the stability of the power supply output, and does not consider that when the energy storage device is used as the main power supply, its remaining capacity continues to decrease as the power supply time increases. If the main power supply is not replaced in time when it is lower than the threshold, it may cause insufficient power supply to the microgrid. In this embodiment, 20% of the maximum capacity of the energy storage device is selected as the preset first threshold. The implementer can select other values ​​according to the actual situation. The implementer can choose according to the actual situation; calculate the energy storage power supply stability coefficient of each energy storage device in each time window, and the calculation formula is: ; In the formula, CPSI represents the energy storage power supply stability coefficient of each energy storage device in each time window, represents the remaining capacity of each energy storage device at the last acquisition time in each time window, H represents the first threshold of each energy storage device, T represents the number of acquisition times in the time window, , Respectively represent the voltage data and current data of each energy storage device at the i-th collection moment in each time window.

[0056] The product of voltage and current within the time window is summed to obtain the amount of power consumed during this period. The more power the energy storage device consumes within the same period of time, the faster the capacity of the device is consumed, and the less suitable it is to be used as a main power source. After a time window, the closer the remaining capacity of the energy storage device is to the threshold, the less remaining power it has, and the less suitable it is to be used as a main power source.

[0057] The smaller the value of the energy storage power supply stability coefficient, the slower the capacity consumption of the energy storage device and the larger the remaining capacity, that is, the more suitable it is as the main power supply. On the contrary, the faster the capacity consumption of the energy storage device or the smaller the remaining capacity, the less suitable it is as the main power supply.

[0058] It should be noted that when the remaining capacity of the energy storage device is equal to or less than a preset first threshold, other main power sources are switched.

[0059] Furthermore, the power reliability coefficient of each power supply in each time window is calculated according to the characteristics of different power supply equipment. The calculation formula is: ; In the formula, K represents the power reliability coefficient of each power supply device in each time window, norm represents the normalization function, PSI and CPSI represent the power supply stability coefficient and energy storage power supply stability coefficient of each power supply in each time window respectively. It should be noted that when the power supply device is other than the energy storage device, the value of the energy storage power supply stability coefficient is zero.

[0060] The larger the power reliability coefficient, the more reliable the power supply is during the power supply process, the smaller the output power fluctuation is, and the more suitable it is as the main power supply. On the contrary, it means that the output power fluctuation is large, or the remaining capacity of the energy storage device is small when used as the main power supply, and the main power supply should be switched in time.

[0061] The power reliability coefficient calculated above illustrates the stability of the power supply output itself. However, when switching the main power supply, we must also consider the stability of the synchronization between the main power supply and the main power grid before and after the grid-connected process, as well as the stability of the coordinated output between the main power supply and other power supply equipment before and after the grid-off process.

[0062] Step S3, based on the difference between the average voltage of the power supply equipment and the average voltage of the main power grid, and the difference between the average voltage phase of the power supply equipment and the average voltage phase of the main power grid, obtain the grid-connected stability of each power supply equipment in each time subwindow; based on the maximum power of the power supply equipment, the remaining capacity of the energy storage device and the average power data of the generator, obtain the power generation capacity index of each power supply equipment in each time subwindow; based on the difference between the average power data of the power supply equipment and the average power data of the power consumption equipment, and the power generation capacity index, obtain the off-grid stability of each power supply equipment in each time subwindow; use the normalized value of the ratio of the off-grid stability to the grid-connected stability as the power stability coefficient of each power supply equipment in each time subwindow; and obtain the comprehensive weight of each power supply equipment in each time window based on the power reliability coefficient and the power stability coefficient.

[0063] When the microgrid needs to be connected to the main grid, the main power source needs to be synchronized with the main grid, otherwise it may cause an impact on the microgrid and damage the load. Therefore, in order to improve the stability of the grid connection, the power source closest to the main grid should be switched as the main power source before the grid connection to reduce the fluctuation of the grid connection process. Therefore, during the grid connection process and the grid connection operation, the power source that is closer to the main grid is more suitable to be the main power source.

[0064] According to the above analysis, every 1s is taken as a time sub-window, and the voltage signal of each power supply device in each time sub-window is subjected to discrete Fourier transform to obtain the phase information of the voltage signal at each acquisition moment in each time sub-window; discrete Fourier transform is a well-known technology, and the specific steps are not repeated here. The implementer can choose the time length as the length of the time sub-window to calculate the grid-connected stability of each power supply, and the calculation formula is: ; In the formula, GI represents the grid-connected stability of each power supply device in each time sub-window, , They represent the average voltage of each power supply device and the average voltage of the main power grid in the time sub-window. , They respectively represent the phase average value of each power supply device and the phase average value of the main power grid within the time sub-window.

[0065] Since the grid connection process is a relatively fast process, the selected time sub-window length is 1s. The power supply is close to the main grid, in addition to the voltage, the phase should also be close, because in a three-phase power system, if the phase difference is too large, a large impact current will be generated at the moment of grid connection, which should be avoided.

[0066] The smaller the value of the grid-connected stability is, the closer the voltage and phase of the current power supply are to the main power grid, and the smaller the impact of the grid-connected process is, that is, the more suitable it is to become the main power supply. On the contrary, it means that the current power supply is greatly different from the main power supply and is less suitable to become the main power supply.

[0067] When the microgrid needs to operate off-grid, the power supply in the microgrid needs to balance power to provide load for the power-consuming equipment. Therefore, the power supply with higher power is more likely to become the main power supply, and other power supplies are balanced according to the main power supply. Since the output power of each power supply is different, the power generation capacity index of each power supply device in each time sub-window is obtained. The acquisition method is:

[0068] When the power supply device is a diesel generator, the maximum power of the diesel generator is used as the power generation capacity index of the power supply device in each time subwindow; when the power supply device is an energy storage device, the remaining capacity of the energy storage device at the last acquisition moment of each time subwindow is used as the power generation capacity index of the power supply device in each time subwindow; when the power supply device is a wind turbine or a solar generator, the average value of the power data of the generator in the time subwindow is used as the power generation capacity index of the power supply device in each time subwindow.

[0069] Furthermore, in order to characterize the possibility of each power supply device becoming the main power supply, the off-grid stability of each power supply device in each time window is constructed, and the calculation formula is: ; In the formula, OI represents the off-grid stability of each power supply device in each time sub-window; Q is the power generation capacity index of each power supply device in each time sub-window, N and M represent the number of power supply devices and the number of power consumption devices in the microgrid respectively. represents the mean value of the power data of the ith power supply device in each time sub-window, Represents the mean value of the power data of the jth electrical equipment in each time sub-window.

[0070] The greater the power generation capacity of a power source and the larger the adjustment space, the more suitable it is to become the main power source. In addition, power balance needs to be ensured in the microgrid, that is, the output power is equal to the power consumption. The greater the difference between them, the more it is necessary to switch the main power source, otherwise a failure may occur.

[0071] The larger the value of the off-grid stability is, the greater the power generation capacity of the current power supply is, or the power in the current microgrid is unbalanced and the main power supply needs to be switched, that is, the current power supply is more suitable to be the main power supply. On the contrary, it means that the power generation capacity of the current power supply is insufficient, or the power balance of the microgrid does not require switching the main power supply, that is, the current power supply is less suitable to be the main power supply.

[0072] Furthermore, the stability of the power supply is calculated based on the grid-connected stability and off-grid stability of the power supply. Taking one of the power supplies as an example, one calculation method is: ;W represents the power stability coefficient of each power supply device in each time sub-window, norm() represents the normalization function, GI represents the grid-connected stability of each power supply device in each time sub-window, and OI represents the off-grid stability of each power supply device in each time sub-window. The larger the power stability coefficient, the more suitable the current power supply is to become the main power supply before grid connection and after off-grid. On the contrary, the less suitable the current power supply is to become the main power supply. Selecting a power supply with a large power stability coefficient as the main power supply can reduce the impact current and power fluctuation caused by the switching of the microgrid operation state and avoid failures.

[0073] Furthermore, the analytic hierarchy process is a multi-dimensional criterion decision analysis method. Using the analytic hierarchy process to determine the main power supply can provide a comprehensive evaluation and quantitative analysis, so that the selected main power supply is more appropriate. In this embodiment, the target layer is to select the main power supply, the criterion layer is set to the power reliability coefficient of the power supply equipment in each time window and the average of all power stability coefficients of the power supply equipment in each time window, and the solution layer is each power supply equipment, and the comprehensive weight of each power supply equipment in each time sub-window is output.

[0074] Optionally, implementers can add more selection criteria based on actual conditions, such as environmental friendliness, by collecting carbon emissions generated by different power sources during the same working hours through sensors; cost, by calculating the cost of different power sources during the same working hours.

[0075] Step S4, selecting the main power source in each time window according to the comprehensive weight, and remotely controlling the power grid.

[0076] The optional power supplies are sorted from large to small according to the comprehensive weight, and the power supply device with the largest comprehensive weight is selected as the main power supply of each time sub-window. The hierarchical analysis method is a well-known technology, and the specific steps are not repeated here.

[0077] At this point, the main power source is determined.

[0078] The cloud platform continuously monitors the operating status of the microgrid. When the microgrid is running smoothly, that is, connected to the grid or in a grid-connected state, there is no need to switch the main power supply unless the main power supply fails or changes its state. At this time, the main power supply is selected once every time window.

[0079] When the operating state of the microgrid changes, that is, before or after grid connection, in order to ensure the stability and power balance of the microgrid, it is likely that the main power supply needs to be switched. After the cloud platform issues a grid connection instruction, the system calculates the stability and selects a new main power supply through the analytic hierarchy process before performing the grid connection operation; similarly, after completing the off-grid operation issued by the cloud platform, the stability is calculated and a new main power supply is selected through the analytic hierarchy process. By switching the main power supply, the stability and power balance of the microgrid can be ensured after the operating state changes, reducing the occurrence of faults.

[0080] The main power switching diagram is as follows Figure 2 As shown in the figure, after the off-grid operation of the microgrid and the main grid, the main power source is switched from power source 3 to power source 1; the schematic diagram of the power fluctuation of the microgrid is shown in Figure 3 As shown in the figure, after the microgrid is off-grid, the power difference fluctuation increases, and after the main power supply is switched, the power difference fluctuation decreases, maintaining the power balance of the microgrid. So far, a cloud platform-based remote control method for power grids has been completed.

[0081] Based on the same inventive concept as the above method, an embodiment of the present application also provides a cloud platform-based power grid remote control system, including a memory, a processor, and a computer program stored in the memory and running on the processor, and when the processor executes the computer program, the steps of any one of the above-mentioned cloud platform-based power grid remote control methods are implemented.

[0082] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0083] The various embodiments in the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0084] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A cloud platform-based power grid remote control method, characterized in that: The method comprises the following steps: Collect voltage data of the main power grid; collect voltage data, current data, frequency data and power data of each power supply device and each power-consuming device; power supply devices include diesel generators, energy storage devices, wind turbines and solar generators, and collect the remaining capacity of energy storage devices; Based on the difference between the voltage data of the power supply device and the preset output voltage, and the difference between the frequency data and the preset output frequency, the power supply stability coefficient of each power supply device in each time window is obtained; based on the remaining capacity, voltage data, and current data of the energy storage device, the energy storage power supply stability coefficient of each energy storage device in each time window is obtained; Obtain the power reliability coefficient of each power supply device in each time window based on the power supply stability coefficient and the energy storage power supply stability coefficient; Based on the difference between the average voltage of the power supply device and the average voltage of the main grid, and the difference between the average phase of the voltage of the power supply device and the average phase of the voltage of the main grid, the grid connection stability of each power supply device in each time subwindow is obtained; Based on the maximum power of the power supply equipment, the remaining capacity of the energy storage equipment and the average power data of the generator, the power generation capacity index of each power supply equipment in each time sub-window is obtained; based on the difference between the average power data of the power supply equipment and the average power data of the power consumption equipment, and the power generation capacity index, the off-grid stability of each power supply equipment in each time sub-window is obtained; The normalized value of the ratio of off-grid stability to grid-connected stability is used as the power stability coefficient of each power supply device in each time sub-window; the comprehensive weight of each power supply device in each time window is obtained based on the power reliability coefficient and the power stability coefficient; Select the main power source in each time window according to the comprehensive weight and remotely control the power grid; The calculation formula of the power supply stability coefficient is: ; In the formula, PSI represents the power supply stability coefficient of each power supply device in each time window; T represents the number of sampling moments in the time window, , Respectively represent the voltage data and frequency data of each power supply device at the i-th acquisition moment in each time window, , Respectively represent the preset output voltage and preset output frequency of each power supply device; The calculation formula of the energy storage power supply stability coefficient is: ; In the formula, CPSI represents the energy storage power supply stability coefficient of each energy storage device in each time window, represents the remaining capacity of each energy storage device at the last acquisition moment in each time window, H represents the preset first threshold of each energy storage device, T represents the number of acquisition moments in the time window, , Respectively represent the voltage data and current data of each energy storage device at the i-th acquisition moment in each time window; The method for obtaining the power supply reliability coefficient is: For each power supply device in each time window, when the power supply device is other than the energy storage device, the value of the energy storage power supply stability coefficient is set to 0, and the normalized value of the sum of the power supply stability coefficient of each power supply device and the energy storage power supply stability coefficient is calculated, and the difference between the value 1 and the normalized value is calculated as the power supply reliability coefficient of each power supply device; The method for obtaining the grid-connected stability is: For each power supply device and the main power grid, a discrete Fourier transform is performed on the voltage signal in each time sub-window to obtain the phase information of the voltage signal at each acquisition moment; For each time sub-window, the absolute value of the difference between the voltage average value of each power supply device and the voltage average value of the main power grid is calculated as the first absolute value of the difference, the absolute value of the difference between the phase average value of each power supply device and the phase average value of the main power grid is calculated as the second absolute value of the difference, and the product of the first absolute value of the difference and the second absolute value of the difference is used as the grid-connected stability of each power supply in each time sub-window; The method for obtaining the power generation capacity index is: When the power supply device is a diesel generator, the maximum power of the diesel generator is used as the power generation capacity index of the power supply device in each time sub-window; When the power supply device is an energy storage device, the remaining capacity of the energy storage device at the last acquisition moment of each time sub-window is used as the power generation capacity index of the power supply device in each time sub-window; When the power supply device is a wind turbine or a solar power generator, the average value of the power data of the generator in the time sub-window is used as the power generation capacity index of the power supply device in each time sub-window; The calculation formula of the off-grid stability is: ; In the formula, OI represents the off-grid stability of each power supply device in each time sub-window; Q is the power generation capacity index of each power supply device in each time sub-window, N and M represent the number of power supply devices and the number of power consumption devices in the microgrid respectively. represents the mean value of the power data of the ith power supply device in each time sub-window, represents the mean value of the power data of the jth electrical equipment in each time sub-window; The obtaining of the comprehensive weight of each power supply device in each time window based on the power supply reliability coefficient and the power supply stability coefficient includes: The target layer of the analytic hierarchy process is set to select the main power source, the criterion layer is set to the power reliability coefficient of the power supply equipment in each time window and the average of all power stability coefficients of the power supply equipment in each time window, the solution layer is each power supply equipment, and the comprehensive weight of each power supply equipment in each time window is output; The method of selecting the main power source in each time window according to the comprehensive weight and remotely controlling the power grid includes: For each time window, the power supply device with the largest comprehensive weight is used as the main power supply for each time window. The main power supply is switched once every time window. The main power supply is switched once when the operating status of the microgrid changes, and the power supply is remotely controlled.

2. A cloud platform-based power grid remote control system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the cloud platform-based power grid remote control method as claimed in claim 1 are implemented.

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