A complementary substitution system and method for electric, gas, cooling, and heating energy supply systems.

Abstract

This invention relates to the field of power supply system compensation control technology, specifically to a complementary substitution system and method for electric, gas, cooling, and heating energy supply systems. The invention first obtains the grid frequency, the start and end times of each frequency instability period, the delay time of the corresponding compensation conversion device, and the remaining capacity of the energy storage device. Further, it divides the start time and obtains the compensation effect coefficient and compensation delay time for each conversion device within the instability time interval. Finally, it compares the grid frequency fluctuation characteristics of the first half of the current instability time interval with the grid frequency fluctuation characteristics within a preset historical neighborhood of the corresponding historical start time. Combining the changes in remaining capacity, compensation effect coefficients, and compensation delay time, it controls the conversion device to pre-start for frequency compensation, optimizing the pre-start strategy of the conversion device, improving the timeliness and accuracy of frequency compensation, reducing the impact of response delay, and enhancing the frequency compensation effect.

Description

Technical Field

[0001] This invention relates to the field of power supply system compensation and control technology, specifically to a complementary substitution system and method for electric, gas, cooling, and heating energy supply systems. Background Technology

[0002] An integrated energy system refers to a system that integrates various energy sources such as coal, oil, natural gas, electricity, and heat within a certain area by utilizing advanced physical information technology and innovative management models, and achieves coordinated planning, optimized operation, collaborative management, and mutual support among various heterogeneous energy subsystems.

[0003] In multi-energy conversion (electricity, gas, cooling, and heating), inertia effect and time delay effect are two core dynamic characteristics that directly affect system stability, response speed, and the design of complementary control strategies. The inertia effect represents the physical inertia of energy storage or release, determining the lower limit of the response speed. The time delay effect represents the time between input command and actual output, determining the effective energy replenishment time. These dynamic characteristics significantly affect the system's power regulation capability, especially when dealing with rapid load fluctuations, easily leading to timing mismatches such as untimely or over-compensated replenishment. Summary of the Invention

[0004] To address the technical problem that existing multi-energy conversion control systems suffer from unsatisfactory compensation effects due to time delay effects, the present invention aims to provide a complementary substitution system and method for electric, gas, cooling, and heating energy supply systems. The specific technical solution adopted is as follows:

[0005] A method for complementary substitution of electric, gas, cooling, and heating energy supply systems, the method comprising:

[0006] The grid frequency, start and end times of each frequency instability period, delay time of the corresponding compensation conversion device, and remaining capacity of the energy storage device are obtained for each type of load. The loads include four types: electricity, gas, cooling, and heating, and each type of load is taken as the target load.

[0007] In the historical data of the target load, similar start times on different days are divided into the same unstable time interval; based on the relative length of each frequency instability period and the corresponding delay time, the compensation effect coefficient of each conversion device in the unstable time interval is obtained; based on the compensation effect coefficient and the length of the delay time, the compensation delay time of each conversion device of the target load in each unstable time interval is obtained;

[0008] The fluctuation characteristics of the power grid frequency in the first half of the current unstable time interval are compared with the fluctuation characteristics of the power grid frequency in the preset neighborhood of the corresponding historical start time. Combined with the change of the remaining capacity, the compensation effect coefficient and the compensation delay time, the conversion device is controlled to pre-start frequency compensation.

[0009] Furthermore, the method for obtaining the unstable time interval includes:

[0010] Map the start times of all the frequency unstable periods in the historical data onto the timeline of the same day; starting from the first start time on the timeline, divide the start times within a preset interval length of the first start time into an unstable time interval; repeat this process starting from the remaining undivided first start time to obtain all the unstable time intervals; the time domain length of the unstable time interval is the preset interval length.

[0011] Furthermore, the method for obtaining the compensation effect coefficient includes:

[0012] Within any of the unstable time intervals of the target load, based on the overall characteristics of the ratio of the length of the delay time to the length of the corresponding frequency unstable period when each conversion device performs compensation, the compensation effect coefficient of each conversion device for the target load in the corresponding unstable time interval is obtained; the overall characteristics of the ratio of the length of the delay time to the length of the corresponding frequency unstable period are positively correlated with the compensation effect coefficient.

[0013] Furthermore, the method for obtaining the compensation delay time includes:

[0014] For any unstable time interval of any of the conversion devices, when the compensation effect coefficient is greater than the preset effect threshold, the compensation delay time is set to 0.

[0015] When the compensation effect coefficient is less than or equal to the preset effect threshold, the compensation delay time is obtained based on the difference between the compensation effect coefficient and the preset effect threshold, combined with the overall characteristics of the delay time of the corresponding conversion device within the unstable time interval; the difference between the compensation effect coefficient and the preset effect threshold, as well as the overall characteristics of the delay time, are all positively correlated with the compensation delay time.

[0016] Furthermore, the method for controlling the pre-start of the conversion device to perform frequency compensation includes:

[0017] The current unstable time interval is taken as the target interval; the current instability coefficient is obtained based on the range and variance of the power grid frequency in the first half of the target interval; the range and variance of the power grid frequency in the preset historical neighborhood of each starting time are fused into the historical data of the target interval to obtain the instability reference coefficient of the target interval; the current instability coefficient and the instability reference coefficient are used to determine whether to pre-start the conversion device for frequency compensation.

[0018] When pre-start is determined, a selection sequence of conversion devices is obtained based on the variation characteristics of the remaining capacity of the energy storage device corresponding to each conversion device and the compensation effect coefficient corresponding to each conversion device; in the historical data of the target interval, a pre-start compensation sequence is obtained based on the compensation delay time of each conversion device for the overall target load and the selection sequence.

[0019] Select an available conversion device from the selection sequence, and combine it with the corresponding element value in the pre-start compensation sequence to pre-start the corresponding conversion device to perform frequency compensation for the target load.

[0020] Furthermore, the method for determining whether to pre-start the conversion device for frequency compensation includes:

[0021] When the instability coefficient is greater than or equal to the instability reference coefficient, it is determined that the pre-start conversion device will perform frequency compensation.

[0022] Furthermore, the method for obtaining the selection sequence includes:

[0023] Based on the overall rate of change of the remaining capacity of the energy storage device corresponding to each conversion device and the real-time remaining capacity, the remaining compensable time of each conversion device for the target load is obtained; the remaining compensable time and the compensation effect coefficient are combined to obtain the selection coefficient of each conversion device; the remaining compensable time and the compensation effect coefficient are both positively correlated with the selection coefficient;

[0024] The conversion devices are sorted from largest to smallest according to the selected coefficient to obtain a selection sequence of conversion devices.

[0025] Furthermore, the method for obtaining the pre-startup compensation sequence includes:

[0026] The compensation delay times are sorted according to the sorting order in the selected sequence to obtain the pre-start compensation sequence.

[0027] Furthermore, the preset historical neighborhood has a length of 30 minutes.

[0028] The present invention also proposes a complementary substitution system for electric, gas, cooling, and heating energy supply systems. The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of any one of the complementary substitution methods for electric, gas, cooling, and heating energy supply systems.

[0029] The present invention has the following beneficial effects:

[0030] This invention first obtains the grid frequency, the start and end times of each period of frequency instability, the delay time of the conversion device, and the remaining capacity of the energy storage device, providing a foundation for data analysis. It further divides similar start times across different days to facilitate analysis of grid frequency instability patterns at different times each day, enabling precise frequency compensation control. It then obtains the compensation effect coefficient of each conversion device within the unstable time interval, quantitatively representing the compensation effect of each device on the target load in different unstable time intervals, providing a basis for accurate subsequent frequency compensation. Furthermore, it obtains the compensation delay time of each conversion device for the target load in each unstable time interval, providing a basis for pre-starting the conversion device, making the device startup more aligned with system requirements and improving the accuracy and adaptability of frequency compensation. Finally, it compares the grid frequency fluctuation characteristics of the first half of the current unstable time interval with the grid frequency fluctuation characteristics within a preset historical neighborhood at the corresponding historical start time to predict the likelihood of future frequency instability. Combining the changes in remaining capacity, compensation effect coefficients, and compensation delay time, it selects the most suitable conversion device and controls its pre-start for frequency compensation. Based on the characteristics of power grid frequency fluctuations and combined with historical data analysis, this invention calculates the compensation effect coefficient, compensation delay time, and pre-start advance, optimizes the pre-start strategy of the conversion device, improves the timeliness and accuracy of frequency compensation, reduces the impact of response delay, enhances the frequency compensation effect, and better maintains power grid stability. Attached Figure Description

[0031] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A flowchart illustrating a complementary substitution method for an electric, gas, cooling, and heating energy supply system according to an embodiment of the present invention;

[0033] Figure 2This is a flowchart illustrating a method for pre-starting a control conversion device to perform frequency compensation, as provided in an embodiment of the present invention. Detailed Implementation

[0034] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a complementary substitution system and method for electric, gas, cooling, and heating energy supply systems proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0035] Unless otherwise defined, 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 invention pertains.

[0036] The following description, in conjunction with the accompanying drawings, details the specific scheme of the complementary substitution system and method for electric, gas, cooling, and heating energy supply systems provided by the present invention.

[0037] See also Figure 1 The diagram illustrates a flowchart of a complementary substitution method for electric, gas, cooling, and heating energy supply systems according to an embodiment of the present invention, specifically including:

[0038] Step S1: Obtain the grid frequency for each type of load, the start and end times of each period of frequency instability, the delay time of the corresponding compensation conversion device, and the remaining capacity of the energy storage device; the load includes four types of loads: electricity, gas, cooling, and heating, and each type of load is taken as the target load.

[0039] In one embodiment of the present invention, the integrated energy management system consists of four modules: load, energy storage device, energy input and conversion device.

[0040] Energy input modules include wind power, photovoltaic power, natural gas, and the upstream power grid. Conversion device modules include electric chillers, gas turbines, gas boilers, waste heat boilers, absorption chillers, and heat exchangers. Energy storage devices include batteries and thermal storage tanks. The load side includes four types of loads: electricity, gas, cooling, and heating.

[0041] The data acquisition frequency is set to 3 seconds / time. The grid frequency of each type of load is collected. Frequency instability is determined by the frequency stability detection mechanism in the integrated energy management system. The start and end times of each frequency instability period are recorded. The delay time of the corresponding compensation conversion device is also recorded. The remaining capacity of each energy storage device is collected to provide a basis for data analysis.

[0042] The frequency stability detection mechanism can be as follows: set a fixed threshold of 45-55Hz, and determine that frequency instability occurs when the collected power grid frequency exceeds the fixed threshold.

[0043] First, select any type of load from the loads as the target load, and then analyze each type of load one by one.

[0044] It should be noted that since the analysis method for each type of load is the same, only the target load will be used as an example here, and will not be described again.

[0045] In other embodiments of the present invention, the implementer may adjust the acquisition frequency and set other frequency stability detection mechanisms.

[0046] Step S2: In the historical data of the target load, divide similar start times in different days into the same unstable time interval; according to the relative length of each frequency unstable period and the corresponding delay time, obtain the compensation effect coefficient of each conversion device in the unstable time interval; based on the compensation effect coefficient and the length of the delay time, obtain the compensation delay time of each conversion device in each unstable time interval of the target load.

[0047] Considering that most power grid users consume electricity on a daily basis, the historical data of the target load is divided into the same unstable time interval for similar start times in different days. This makes it easier to analyze the unstable patterns of the power grid frequency at different times of the day, and helps to set the most appropriate compensation method in different unstable time intervals, so as to accurately control the frequency compensation.

[0048] Preferably, in one embodiment of the present invention, the start times of all frequency unstable periods in the historical data are first mapped onto the timeline of the same day to facilitate the division of time intervals. The timeline runs from 0:00 to 24:00, and each data point on the timeline corresponds to the start time of a frequency unstable period.

[0049] Then, starting from the first start time on the timeline, the start times within the neighborhood of the preset interval length of the first start time are divided into an unstable time interval;

[0050] Then, starting from the first undivided initial moment, all unstable time intervals are obtained; the time domain length of the unstable time interval is the preset interval length.

[0051] As an example, the preset interval length is 30 minutes, and the starting times are sorted from left to right with the rightward direction as the positive time domain.

[0052] For example: if the starting times are 180, 200, 220, 225, 230, and 300, in minutes, before the first division, the first starting time is 180, and before the second division, the first undivided starting time is 220; then the first unstable time interval is [180, 210), which includes 180 and 200; the second unstable time interval is [220, 250), which includes 200, 225, and 230; and the third unstable time interval is [300, 330), which includes 300.

[0053] In another embodiment of the present invention, the implementer may also directly divide the 0-24 hours of each day into equal parts, such as dividing it into 48 segments, with each time interval serving as an unstable time interval.

[0054] It should be noted that, in one embodiment of the present invention, the historical data of the most recent 7 days of the current day is obtained for analysis, and the range of historical data is limited. The implementer can adjust this limit as needed.

[0055] Considering that the relative length of the frequency instability period and the corresponding delay time reflects the delay characteristics and response capability of the conversion device, the compensation effect coefficient of each conversion device in the unstable time interval is obtained according to the relative length of each frequency instability period and the corresponding delay time. This quantitatively represents the compensation effect of each conversion device on the target load in different unstable time intervals, providing a basis for accurate frequency compensation in the future.

[0056] Preferably, in one embodiment of the present invention, considering that the delay time refers to the time from the issuance of the compensation command to the start of the compensation, the longer the delay time is relative to the period of frequency instability, the longer the delay in communication, control and execution before compensation, it means that the shorter the time consumed by the conversion device to restore the frequency to stability after the target load starts frequency compensation, the better the compensation effect. After the subsequent control pre-start eliminates the influence of the delay time, the normal frequency can be quickly restored.

[0057] Based on this, within any unstable time interval of the target load, the compensation effect coefficient of each conversion device for the target load in the corresponding unstable time interval is obtained according to the overall characteristics of the ratio of the length of the delay time when each conversion device performs compensation to the length of the corresponding frequency unstable period.

[0058] Among them, the overall characteristic of the ratio of the length of the delay time to the length of the corresponding frequency instability period is positively correlated with the compensation effect coefficient.

[0059] As an example, the average ratio of the length of the delay time when each conversion device compensates for the target load to the length of the corresponding frequency instability period within any unstable time interval of the target load is taken as the compensation effect coefficient of each conversion device for the target load in the corresponding unstable time interval.

[0060] By comparing the relative lengths of the frequency instability period and the corresponding delay time, the compensation effect coefficient is obtained by using the mean to represent the overall characteristics of the ratio, thus indicating the frequency compensation effect of a conversion device on the target load within a certain period of instability.

[0061] As another example, implementers can also obtain the mean, mode, and median of the ratio of the length of the delay time when each conversion device is compensating to the length of the corresponding frequency instability period, and perform weighted summation with weights of 0.5, 0.3, and 0.2 or other weights. The overall characteristics of the ratio can be represented by the weighted summation to obtain the compensation effect coefficient.

[0062] Considering that the compensation effect coefficient represents the frequency compensation effect of a conversion device on the target load within an unstable time interval, and the length of the delay time represents the response speed of the conversion device, the compensation delay time of each conversion device in each unstable time interval is obtained based on the compensation effect coefficient and the length of the delay time. This provides a basis for the subsequent pre-start of the conversion device, making the start-up of the conversion device more in line with system requirements and improving the accuracy and adaptability of frequency compensation.

[0063] Preferably, in one embodiment of the present invention, considering that when the compensation effect coefficient of the conversion device is large, it indicates that the conversion device has a good compensation effect on the target load in the corresponding unstable time interval and there is no need to compensate for the delay time, for any unstable time interval of any conversion device, when the compensation effect coefficient is greater than the preset effect threshold, the compensation delay time is set to 0.

[0064] When the compensation effect coefficient of the conversion device is small, compensation is required. The smaller the compensation effect coefficient, the longer the delay time, indicating that the compensation effect of the conversion device on the target load is worse in the corresponding unstable time interval, the greater the delay of starting compensation, and the greater the amount of compensation for the delay time needs to be.

[0065] Based on this, when the compensation effect coefficient is less than or equal to the preset effect threshold, the compensation delay time is obtained by combining the difference between the compensation effect coefficient and the preset effect threshold with the overall characteristics of the delay time of the corresponding conversion device within the corresponding unstable time interval; the difference between the compensation effect coefficient and the preset effect threshold, as well as the overall characteristics of the delay time, are all positively correlated with the compensation delay time.

[0066] As an example, the compensation effect coefficient is linearly normalized, and the preset effect threshold is 0.5;

[0067] When the compensation effect coefficient is less than or equal to the preset effect threshold, for any type of conversion device in any unstable time interval, the difference between the preset effect threshold and the compensation effect coefficient is normalized and multiplied by the mean of the delay time of the corresponding conversion device in the corresponding unstable time interval. The product is used as the compensation delay time of the corresponding conversion device in the corresponding unstable time interval.

[0068] Here, the mean of the delay time represents the overall characteristics of the delay time, and the difference between the preset effect threshold and the compensation effect coefficient represents the difference between the compensation effect coefficient and the preset effect threshold; normalization can be linear normalization.

[0069] In other embodiments of the present invention, the mean, mode, and median of the delay time can be obtained and fused in a weighted summation manner to represent the overall characteristics of the delay time, which will not be elaborated further.

[0070] In another embodiment of the present invention, it is also considered that the length of the frequency instability period represents the time when the system deviates from the stable state, which reflects the degree of abnormal deviation of the target load. Therefore, the compensation delay time can also be obtained by combining the length of the frequency instability period.

[0071] As an example, considering that the longer the period of frequency instability is, the more severe the fluctuations are within that time interval, the greater the compensation required to adjust to a stable state, and the longer the compensation delay may be to ensure the compensation effect;

[0072] Therefore, when the compensation effect coefficient is less than or equal to the preset effect threshold, for any type of conversion device in any unstable time interval, the product of the difference between the preset effect threshold and the compensation effect coefficient and the length of the frequency unstable period is normalized and then multiplied by the mean of the delay time of the corresponding conversion device in the corresponding unstable time interval. The product is used as the compensation delay time of the corresponding conversion device in the corresponding unstable time interval.

[0073] Step S3: Compare the grid frequency fluctuation characteristics of the first half of the current unstable time interval with the grid frequency fluctuation characteristics of the preset historical neighborhood at the corresponding historical start time. Combine the changes in remaining capacity, compensation effect coefficient and compensation delay time to control the conversion device to start in advance for frequency compensation.

[0074] Considering that during the actual operation of the day, when the time reaches halfway through each unstable time interval, there is already a large amount of grid frequency data available for analysis, the grid frequency fluctuation characteristics in the first half of the current unstable time interval represent the grid frequency change trend and fluctuation intensity of the target load under the current system operating state; in the historical data corresponding to the current unstable time interval, the grid frequency fluctuation characteristics within the preset historical neighborhood at the historical starting moment represent the typical evolution pattern of grid frequency instability. By comparing the two, the possibility of future frequency instability can be predicted.

[0075] Meanwhile, the change in remaining capacity represents the energy supply situation of the energy storage device's frequency compensation; the compensation effect coefficient represents the compensation effect of different conversion devices on the target load in the current unstable time interval, providing a basis for selecting conversion devices; the compensation delay time represents the compensation for the delay time of the conversion device.

[0076] Therefore, by combining the changes in remaining capacity, the compensation effect coefficient, and the compensation delay time, the conversion device is controlled to start in advance for frequency compensation; by combining historical data with real-time data for intelligent prediction, the conversion device is controlled to respond in advance, reducing the impact of time delay effect, optimizing the allocation of compensation resources, and improving system stability.

[0077] Preferably, in one embodiment of the present invention, please refer to Figure 2 The diagram illustrates a flowchart of a method for pre-starting a control conversion device to perform frequency compensation according to an embodiment of the present invention, specifically including:

[0078] Step S301: Take the current unstable time interval as the target interval; obtain the current instability coefficient based on the range and variance of the power grid frequency in the first half of the target interval; in the historical data of the target interval, integrate the range and variance of the power grid frequency in the preset historical neighborhood at each starting moment to obtain the instability reference coefficient of the target interval; determine whether to pre-start the conversion device for frequency compensation based on the current instability coefficient and the instability reference coefficient.

[0079] First, we take the current unstable time interval as the target interval for easier subsequent description.

[0080] Considering the instability of the power grid frequency when there are drastic fluctuations, the range of the power grid frequency represents the fluctuation range of the power grid frequency. The larger the fluctuation range, the more drastic the fluctuation and the greater the instability. The larger the variance of the power grid frequency, the greater the dispersion of the power grid frequency, the more drastic the fluctuation and the greater the instability.

[0081] Therefore, by using the range and variance of the power grid frequency, the instability characteristics of the power grid frequency can be quantified. Based on the current instability coefficient and instability reference coefficient, it can be analyzed whether the current power grid frequency will evolve into frequency instability, and thus determine whether to pre-start the conversion device for frequency compensation.

[0082] As an example, the product of the range and variance of the power grid frequency in the first half of the current target interval is used as the current instability coefficient; the range and variance are combined by multiplication, and the instability coefficient represents the fluctuation characteristics of the power grid frequency in the first half of the current unstable time interval.

[0083] The preset time domain length of the historical neighborhood is 30 minutes; in the historical data of the target interval, the product of the range and variance of the power grid frequency in the first 30 minutes of each starting moment is used as the unstable reference sub-coefficient of each starting moment; the average value of the unstable reference sub-coefficients of all starting moments in the target interval is used as the unstable reference coefficient of the target interval.

[0084] When the instability coefficient is greater than or equal to the instability reference coefficient, the pre-start conversion device is determined to perform frequency compensation.

[0085] As another example, after linearly normalizing the range and variance of the power grid frequency, they are then fused by addition or weighted summation to obtain the instability coefficient and the instability reference sub-coefficient.

[0086] It should be noted that in other embodiments of the present invention, the implementer may also obtain the mean, mode and median of the unstable reference sub-coefficients, and obtain the unstable reference coefficients by weighted summation; and set preset historical neighborhoods of other lengths.

[0087] Step S302: When pre-start is determined, the selection sequence of the conversion device is obtained based on the change characteristics of the remaining capacity of the energy storage device corresponding to each conversion device and the compensation effect coefficient corresponding to each conversion device; in the historical data of the target range, the pre-start compensation sequence is obtained based on the compensation delay time of each conversion device for the overall target load and the selection sequence.

[0088] When determining pre-start, it is necessary to determine the pre-start conversion device and the pre-start advance time.

[0089] Considering the variation characteristics of the remaining capacity of the energy storage device corresponding to each conversion device, which represents the remaining time available for the energy storage device to perform frequency compensation, and the compensation effect coefficient representing the compensation effect of the conversion device on the target load in the current unstable time interval, the selection sequence is obtained in this way to determine the selection priority of different conversion devices, so as to select the most suitable conversion device for frequency compensation.

[0090] In one embodiment of the present invention, the remaining compensable time for the target load of each conversion device is first obtained based on the overall rate of change of the remaining capacity of the energy storage device corresponding to each conversion device and the real-time remaining capacity.

[0091] As an example, in the historical data of the current target range, the average slope of the remaining capacity change of the corresponding energy storage device is obtained when any type of conversion device performs frequency compensation for the target load. The absolute value is taken as the energy consumption rate, which represents the overall rate of change of the remaining capacity. The ratio of the real-time remaining capacity to the energy consumption rate is normalized and taken as the remaining compensable time of the corresponding conversion device for the current target load.

[0092] As another example, the remaining capacity change curve of the energy storage device corresponding to each conversion device is obtained on the current day. The average slope of the energy consumption curve segment in the remaining capacity change curve is obtained, and the absolute value is taken as the energy consumption rate, thereby obtaining the remaining compensable time. This simplifies the analysis process, sacrificing some accuracy to improve the calculation speed.

[0093] It should be noted that normalization can be achieved using linear normalization or existing normalization functions such as the sigmoid function; when the mean slope of the remaining capacity change of the energy storage device is greater than 0, it indicates that the energy consumption rate of the corresponding energy storage device for frequency compensation is less than the charging rate, and the remaining compensable time is directly set to 1.

[0094] Then, the remaining compensable time and the compensation effect coefficient are combined to obtain the selection coefficient for each conversion device.

[0095] Since a longer remaining compensable time corresponds to a larger compensation effect coefficient, it indicates that the corresponding conversion device has more energy reserves, a better compensation effect, and is more likely to be selected for frequency compensation. Therefore, both the remaining compensable time and the compensation effect coefficient are positively correlated with the selection coefficient.

[0096] As an example, the product of the remaining compensable time and the compensation effect coefficient is used as the selection coefficient for the corresponding conversion device in the current unstable time interval.

[0097] Finally, the conversion devices are sorted from largest to smallest by the selection coefficient to obtain the selection sequence of the conversion devices; the smaller the sequence number of the conversion device, the higher the selection priority.

[0098] The selection sequence determines the compensation priority of the conversion devices. In order to facilitate the adjustment of the start-up time of each conversion device and achieve accurate pre-start, a pre-start compensation sequence is obtained from the historical data of the target range based on the compensation delay time of each conversion device for the overall target load, combined with the selection sequence.

[0099] As an example, sorting the compensation delay time in the selected sequence yields a pre-launch compensation sequence.

[0100] Step S303: Select the first available conversion device from the selection sequence, and combine it with the corresponding element value in the pre-start compensation sequence to pre-start the corresponding conversion device to perform frequency compensation for the target load.

[0101] Considering that the conversion device may malfunction or be occupied, and that the smaller the sequence number of the conversion device in the selection sequence, the higher the selection priority, the first available conversion device is selected from the selection sequence. The corresponding element value in the pre-start compensation sequence is used as the pre-start advance time. The conversion device corresponding to the pre-start performs frequency compensation on the target load.

[0102] It should be noted that when performing frequency compensation on the target load, it is necessary to use the energy source to compensate for the conversion device of other loads, and only the conversion device of other loads as energy sources should be considered.

[0103] It should be noted that the method of frequency compensation for a certain load through a conversion device is a well-known technique in the art, and will not be elaborated here.

[0104] An embodiment of the present invention also provides a complementary substitution system for electric, gas, cooling, and heating energy supply systems. The system includes a memory, a processor, and a computer program. The memory is used to store the corresponding computer program, and the processor is used to run the corresponding computer program. When the computer program runs in the processor, it can implement the complementary substitution method for electric, gas, cooling, and heating energy supply systems described in steps S1-S3.

[0105] In summary, to address the technical problem of unsatisfactory compensation effects caused by time delay effects in existing multi-energy conversion control, this invention first obtains the grid frequency for each load, the start and end times of each frequency instability period, the delay time of the corresponding compensation conversion device, and the remaining capacity of the energy storage device. Further, in the historical data of the target load, similar start times from different days are grouped into the same unstable time interval. Further, based on the relative length of each frequency instability period and the corresponding delay time, the compensation effect coefficient of each conversion device within the unstable time interval is obtained. Further, based on the compensation effect coefficient and the length of the delay time, the compensation delay time of each conversion device for the target load in each unstable time interval is obtained. Finally, the fluctuation characteristics of the grid frequency in the first half of the current unstable time interval are compared with the fluctuation characteristics of the grid frequency in the preset historical neighborhood of the corresponding historical start time. Combining the changes in remaining capacity, the compensation effect coefficient, and the compensation delay time, the conversion device is controlled to pre-start for frequency compensation.

[0106] Based on the characteristics of power grid frequency fluctuations and combined with historical data analysis, this invention calculates the compensation effect coefficient, compensation delay time, and pre-start advance, optimizes the pre-start strategy of the conversion device, improves the timeliness and accuracy of frequency compensation, reduces the impact of response delay, enhances the frequency compensation effect, and better maintains power grid stability.

[0107] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0108] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for complementary substitution of electric, gas, cooling, and heating energy supply systems, characterized in that, The method includes: The grid frequency, start and end times of each frequency instability period, delay time of the corresponding compensation conversion device, and remaining capacity of the energy storage device are obtained for each type of load. The loads include four types: electricity, gas, cooling, and heating, and each type of load is taken as the target load. In the historical data of the target load, similar start times on different days are divided into the same unstable time interval; based on the relative length of each frequency instability period and the corresponding delay time, the compensation effect coefficient of each conversion device in the unstable time interval is obtained; based on the compensation effect coefficient and the length of the delay time, the compensation delay time of each conversion device of the target load in each unstable time interval is obtained; The fluctuation characteristics of the power grid frequency in the first half of the current unstable time interval are compared with the fluctuation characteristics of the power grid frequency in the preset historical neighborhood at the corresponding historical start time. Combined with the change of the remaining capacity, the compensation effect coefficient and the compensation delay time, the conversion device is controlled to pre-start frequency compensation. The method for controlling the pre-start of the conversion device to perform frequency compensation includes: The current unstable time interval is taken as the target interval; the current instability coefficient is obtained based on the range and variance of the power grid frequency in the first half of the target interval; the range and variance of the power grid frequency in the preset historical neighborhood of each starting time are fused into the historical data of the target interval to obtain the instability reference coefficient of the target interval; the current instability coefficient and the instability reference coefficient are used to determine whether to pre-start the conversion device for frequency compensation. When pre-start is determined, a selection sequence of conversion devices is obtained based on the variation characteristics of the remaining capacity of the energy storage device corresponding to each conversion device and the compensation effect coefficient corresponding to each conversion device; in the historical data of the target interval, a pre-start compensation sequence is obtained based on the compensation delay time of each conversion device for the overall target load and the selection sequence. The first available conversion device is selected from the selection sequence, and the corresponding conversion device is pre-activated to perform frequency compensation on the target load in combination with the corresponding element value in the pre-start compensation sequence; the smaller the sequence number of the conversion device in the selection sequence, the higher the selection priority.

2. The method for complementary substitution of electric, gas, cooling, and heating energy supply systems according to claim 1, characterized in that, The method for obtaining the unstable time interval includes: Map the start times of all the frequency unstable periods in the historical data onto the timeline of the same day; starting from the first start time on the timeline, divide the start times within a preset interval length of the first start time into an unstable time interval; repeat this process starting from the remaining undivided first start time to obtain all the unstable time intervals; the time domain length of the unstable time interval is the preset interval length.

3. The method for complementary substitution of electric, gas, cooling, and heating energy supply systems according to claim 1, characterized in that, The method for obtaining the compensation effect coefficient includes: Within any of the unstable time intervals of the target load, based on the overall characteristics of the ratio of the length of the delay time to the length of the corresponding frequency unstable period when each conversion device performs compensation, the compensation effect coefficient of each conversion device for the target load in the corresponding unstable time interval is obtained; the overall characteristics of the ratio of the length of the delay time to the length of the corresponding frequency unstable period are positively correlated with the compensation effect coefficient.

4. The method for complementary substitution of electric, gas, cooling, and heating energy supply systems according to claim 1, characterized in that, The method for obtaining the compensation delay time includes: For any unstable time interval of any of the conversion devices, when the compensation effect coefficient is greater than the preset effect threshold, the compensation delay time is set to 0. When the compensation effect coefficient is less than or equal to the preset effect threshold, the compensation delay time is obtained based on the difference between the compensation effect coefficient and the preset effect threshold, combined with the overall characteristics of the delay time of the corresponding conversion device within the unstable time interval; the difference between the compensation effect coefficient and the preset effect threshold, as well as the overall characteristics of the delay time, are all positively correlated with the compensation delay time.

5. The method for complementary substitution of electric, gas, cooling, and heating energy supply systems according to claim 1, characterized in that, The method for determining whether to pre-start the conversion device for frequency compensation includes: When the instability coefficient is greater than or equal to the instability reference coefficient, it is determined that the pre-start conversion device will perform frequency compensation.

6. The method for complementary substitution of electric, gas, cooling, and heating energy supply systems according to claim 1, characterized in that, The method for obtaining the selected sequence includes: Based on the overall rate of change of the remaining capacity of the energy storage device corresponding to each conversion device and the real-time remaining capacity, the remaining compensable time of each conversion device for the target load is obtained; the remaining compensable time and the compensation effect coefficient are combined to obtain the selection coefficient of each conversion device; the remaining compensable time and the compensation effect coefficient are both positively correlated with the selection coefficient; The conversion devices are sorted from largest to smallest according to the selected coefficient to obtain a selection sequence of conversion devices.

7. The method for complementary substitution of electric, gas, cooling, and heating energy supply systems according to claim 1, characterized in that, The method for obtaining the pre-start compensation sequence includes: The compensation delay times are sorted according to the sorting order in the selected sequence to obtain the pre-start compensation sequence.

8. The method for complementary substitution of electric, gas, cooling, and heating energy supply systems according to claim 1, characterized in that, The preset historical neighborhood has a length of 30 minutes.

9. A complementary substitution system for electric, gas, cooling, and heating energy supply systems, the system comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the complementary substitution method for an electric, gas, cooling, and heating energy supply system as described in any one of claims 1 to 8.

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