A New Optimal Scheduling Method for a Power System with Source-Grid-Load-Storage Collaboration

Abstract

This application relates to the technical field of coordinated optimization dispatching of power systems, specifically to a novel power system optimization dispatching method for source-grid-load-storage coordination. The method includes: analyzing the changing trend and extreme distribution of active power, and determining the energy acceptance degree in combination with the dispersion degree of the amplitudes of all the wave peaks; comparing the difference in active power between each reverse moment and the previous moment, and determining the abnormality degree in combination with the dispersion degree of the power grid frequency and the complexity degree of all power factors; based on the energy acceptance degree and the abnormality degree, determining the energy consumption degree, and determining the power supply degree in combination with the difference between all line load rates and the preset heavy load rate within a preset time period to judge the necessity of power dispatching. This application can quickly evaluate the disadvantages caused by the access of new energy power to the power system and quickly adjust and adapt, aiming at the regulation flexibility of the power system to ensure reliable power supply.

Description

Technical Field

[0001] This application relates to the technical field of coordinated optimization scheduling of power systems, and particularly to a new power system optimization scheduling method for source-grid-load-storage coordination. Background Art

[0002] Source-grid-load-storage coordination refers to the organic integration and collaborative interaction of energy sources, power grids, electricity loads, and energy storage systems in a power system. Through intelligent technologies, real-time monitoring of each link is achieved, and the production, transmission, consumption, and storage of energy are optimized. This mode emphasizes the whole-process integrated management from energy production to consumption, aiming to improve the stability, reliability, and sustainability of the power system. As an energy system solution, the new power system optimization scheduling for source-grid-load-storage coordination can meet the needs of energy transformation, promote the transformation of the grid form, and achieve flexible regulation and reliable power supply of the new power system.

[0003] During the process of source-grid-load coordination, the output of new energy power generation changes violently, which will cause frequent fluctuations in the power flow of the grid section and the voltage and frequency of the hub station, and the system regulation ability is seriously insufficient. The problem of "channel grabbing" between conventional energy and new energy is prominent. In the existing technology, the monitoring granularity of key parameters such as the power flow of the grid section and the voltage and frequency is relatively coarse, and it is impossible to accurately evaluate the new energy consumption capacity of the power system and the "channel grabbing" situation, making it difficult to quickly adjust and adapt to the disadvantages of the power system subsequently, resulting in the lack of sufficient flexibility of the power system to maintain the stability of the system and affecting the reliable power supply. Summary of the Invention

[0004] To solve the above technical problems, this application provides a new power system optimization scheduling method for source-grid-load-storage coordination to solve the existing problems.

[0005] The new power system optimization scheduling method for source-grid-load-storage coordination of this application adopts the following technical solutions:

[0006] An embodiment of this application provides a new power system optimization scheduling method for source-grid-load-storage coordination, and this method includes the following steps:

[0007] Real-time collect the active power, reactive power, power factor, grid frequency, line load rate, and line loss of the transmission line corresponding to the grid section in the new power system;

[0008] Fit all the reactive powers within a preset time period before the current moment, analyze the differences between the peaks and their nearest valleys on the fitting curve, and determine the amplitude of each peak; analyze the change trend and extreme distribution of all the active powers within the preset time period, determine the active power distribution value of the transmission line corresponding to the grid section at the current moment, and combine the dispersion degree of the amplitudes of all the peaks to determine the energy acceptance degree of the transmission line corresponding to the grid section at the current moment;

[0009] Mark the moments corresponding to negative active power as reverse moments, compare the differences in active power between each reverse moment and the previous moment, determine the difference degree of the transmission lines corresponding to the grid section at the current moment, and combine the dispersion degree of all grid frequencies and the complexity degree of all power factors within the preset time period to determine the abnormality degree of the transmission lines corresponding to the grid section at the current moment;

[0010] Based on the energy acceptance degree and the abnormality degree, determine the energy consumption degree of the transmission lines corresponding to the grid section at the current moment; measure the differences between the load rates of all lines and the preset heavy load rate within the preset time period, and the differences in line losses between each moment and the previous moment, determine the loss degree, and combine the energy consumption degree to determine the power supply degree of the transmission lines corresponding to the grid section at the current moment;

[0011] Based on the power supply degree, judge the necessity of power dispatching in the process of dispatching and optimizing the new power system at the current moment.

[0012] Preferably, the amplitude of each wave peak is the absolute difference between the peak value of each wave peak and the valley value of its nearest wave trough.

[0013] Preferably, the method for determining the active power distribution value of the transmission lines corresponding to the grid section at the current moment is as follows:

[0014] Use the trend test algorithm to obtain the trend statistic of all active powers within the preset time period before the current moment, and take the product of the range of all active powers within the preset time period and the trend statistic as the active power distribution value of the transmission lines corresponding to the grid section at the current moment.

[0015] Preferably, the energy acceptance degree of the transmission lines corresponding to the grid section at the current moment is the ratio of the active power distribution value to the dispersion degree of all wave peak amplitudes.

[0016] Preferably, the method for determining the difference degree of the transmission lines corresponding to the grid section at the current moment is as follows:

[0017] Calculate the cumulative result of the differences in active power between all reverse moments and the previous moment within the preset time period, and take the product of the cumulative result and the total number of reverse moments as the difference degree of the transmission lines corresponding to the grid section at the current moment.

[0018] Preferably, the expression for the abnormality degree of the transmission lines corresponding to the grid section at the current moment is: ; where represents the abnormality degree of the transmission lines corresponding to the grid section at the current moment; represents the difference degree of the transmission lines corresponding to the grid section at the current moment; represents the standard deviation of all grid frequencies within the preset duration; represents the fractal dimension of all power factors within the preset duration; represents a constant greater than 0 preset.

[0019] Preferably, the expression for the energy consumption degree of the transmission line corresponding to the grid section at the current moment is: ; in the formula, represents the energy consumption degree of the transmission line corresponding to the grid section at the current moment; represents the energy acceptance degree of the transmission line corresponding to the grid section at the current moment; represents the abnormality degree of the transmission line corresponding to the grid section at the current moment; norm( ) represents the normalization function; represents a constant greater than 0 preset.

[0020] Preferably, the expression for the loss degree is: ; in the formula, represents the loss degree of the transmission line corresponding to the grid section at the current moment; represents the cumulative sum of the differences between all line load rates and the preset heavy load rate within the preset duration; represents the difference in line loss between the moment i and its previous moment within the preset duration; I represents the number of all moments within the preset duration; exp( ) represents the exponential function with the natural constant as the base.

[0021] Preferably, the power supply degree of the transmission line corresponding to the grid section at the current moment is the normalized result of the ratio of the energy consumption degree to the loss degree of the line corresponding to the grid section at the current moment.

[0022] Preferably, determining the necessity of power dispatching in the dispatching optimization process of the new power system at the current moment includes:

[0023] If the power supply degree of the transmission line corresponding to the grid section at the current moment is greater than or equal to the preset threshold, then there is no need to perform power dispatching on the grid at the current moment; otherwise, power dispatching on the grid at the current moment is required.

[0024] This application has at least the following beneficial effects:

[0025] This application obtains the energy consumption degree through the energy acceptance degree of the transmission line corresponding to the power grid section and the abnormal condition of the section power flow, can accurately evaluate the consumption level of new energy in the power system with a high time resolution, and provides a method for analyzing the abnormal degree of the power flow direction caused by the access of a high proportion of new energy to the power system, which more accurately reflects the consumption capacity of the power system with source-network-load-storage coordination for new energy power; further, the power supply degree is obtained according to the energy consumption degree and the loss degree, and a method for quantifying the "channel grabbing" situation between conventional energy and new energy according to the line load and the line loss trend is provided, which more accurately reflects the power supply degree state of the power system with source-network-load-storage coordination after the access of new energy; further, the power system state is evaluated through the power supply degree, and according to the power balance condition of the power system, the adjustment capacity of the controllable user load of the power is adjusted, and the charging and discharging state quantities of the energy storage system are controlled to realize the power balance of the power system with source-network-load-storage coordination, which can quickly evaluate the disadvantages caused by the access of new energy power to the power system and quickly adjust and adapt, improve the adjustment flexibility of the power system, and ensure the reliable power supply. Brief Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a flowchart of the steps of a novel power system optimal scheduling method with source-network-load-storage coordination provided by an embodiment of the present application;

[0028] Figure 2 It is a schematic diagram of the power supply degree extraction process provided by an embodiment of the present application. Detailed Embodiments

[0029] In order to further elaborate on the technical means and effects adopted by the present application to achieve the intended invention purpose, the following combines the drawings and preferred embodiments to detail the specific embodiments, structures, features and effects of the novel power system optimal scheduling method with source-network-load-storage coordination proposed according to the present application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0031] The following will specifically describe the specific solution of the novel power system optimal dispatching method for source-grid-load-storage coordination provided by this application in combination with the accompanying drawings.

[0032] A novel power system optimal dispatching method for source-grid-load-storage coordination provided by an embodiment of this application. Specifically, the following novel power system optimal dispatching method for source-grid-load-storage coordination is provided. Please refer to Figure 1 , and this method includes the following steps:

[0033] Step S1: Real-time collect the active power, reactive power, power factor, grid frequency, line load rate, and line loss of the transmission lines corresponding to the grid sections in the novel power system.

[0034] Install PMU synchronous vector measurement devices, smart meters, and power meters at the grid flow sections corresponding to each new energy grid connection node in the power system with source-grid-load-storage coordination. Continuously collect the relevant electrical parameter data of the PQ load nodes and PV load nodes at each grid flow section in the power system. Obtain the relevant parameters of the transmission lines and transformers, and the rated parameters of the generators and loads at each grid flow section through the SCADA intelligent monitoring system. The above-mentioned relevant parameter data of the PQ load nodes are the active power consumption and reactive power consumption, and the relevant electrical parameter data of the PV load nodes are the active power output and voltage amplitude; the relevant parameters of the transmission lines and transformers include the line resistance, reactance, and admittance at the grid section; the rated parameters of the generators and loads are the capacity limits of thermal power generators and new energy generators, and the rated power of the loads, respectively.

[0035] Perform power flow calculation through the data obtained above, and real-time collect the active power, reactive power, power factor, grid frequency, line load rate, and line loss of the transmission lines corresponding to the grid sections in the novel power system. Set the data collection frequency to q.

[0036] Among them, the power flow calculation method, the calculation of the power factor, and the calculation of the line load rate are all well-known technologies, and their specific principles will not be elaborated here.

[0037] It should be supplemented that the value of the data collection frequency q is 10Hz. Implementers can also set it according to specific situations. There is no special restriction in this embodiment.

[0038] Transmit the data obtained above to the data collection system of the power system by means of a fiber optic private network or wireless communication. Use the GPS clock synchronization technology to timestamp it to eliminate time deviation. Predict the missing values of the power calculation results in complex scenarios based on GMDH, and perform normalization processing on the obtained data to eliminate the influence of different dimensions between different data.

[0039] It should be noted that there are many commonly used normalization methods. In this embodiment, the z-score normalization method is used to process the collected data. In actual application, the implementer can also use other normalization methods such as maximum and minimum value normalization method. Regarding the selection of normalization method, this embodiment does not make any special restrictions.

[0040] Among them, the z-score normalization method is a well-known technology, and its specific principle will not be repeated here.

[0041] Step S2: Fit all reactive powers within a preset time period before the current moment, analyze the difference between each peak on the fitting curve and its nearest trough, and determine the amplitude of each peak; analyze the change trend and extreme distribution of all active powers within the preset time period, determine the active power distribution value of the transmission line corresponding to the grid section at the current moment, and determine the energy acceptance of the transmission line corresponding to the grid section at the current moment in combination with the discrete degree of the amplitude of all the peaks.

[0042] During the operation of the power system with coordinated source, grid, load and storage, due to the strong randomness and volatility of the output of renewable energy power, the intervention of a high proportion of renewable energy power may cause drastic fluctuations in the power grid section current corresponding to the renewable energy power grid-connected node. When the power system is unable to accurately monitor its capacity to absorb renewable energy power, it is difficult for the power grid load demand to be effectively matched with renewable energy power generation, which increases the difficulty of peak and frequency regulation of the power system and may even cause the risk of supply and demand imbalance in severe cases.

[0043] Specifically, the stronger the power system with coordinated source, grid, load and storage has the ability to absorb new energy electricity, the higher the power system's acceptance of the randomness and volatility of new energy, and the more the transmission lines can transmit new energy electricity to meet the load demand of the power grid. That is, the more stable the active power increase of the transmission lines at the power grid section, the stronger the reactive power support capacity at the power grid section, and the reactive compensation devices installed in the power system, such as SVC, SVG, etc., have a supporting effect on voltage stability, making the random volatility of reactive power less severe.

[0044] Therefore, based on the above analysis, all reactive powers within the preset time before the current moment are fitted, and the difference between each peak on the fitting curve and its nearest trough is analyzed to determine the amplitude of each peak; the change trend and extreme distribution of all active powers within the preset time are analyzed to determine the active distribution value of the transmission line corresponding to the grid section at the current moment, and the energy acceptance of the transmission line corresponding to the grid section at the current moment is determined in combination with the discrete degree of the amplitude of all the peaks, which is used to characterize the power system's ability to absorb new energy power and the "rushing channel status" of conventional energy and new energy. The specific construction process of energy acceptance is as follows:

[0045] As an implementation manner, in this embodiment, all reactive powers within a preset time period before the current moment are fitted, and the absolute difference between the peak value of each peak on the fitting curve and the valley value of its nearest valley is used as the amplitude of each peak; wherein, the absolute difference means taking the absolute value of the difference.

[0046] It should be supplementary explained that the value of the preset time period is set artificially. In this embodiment, the value of the preset time period is 24h. The implementer can also set it according to the specific situation by himself / herself, and this embodiment does not make special restrictions.

[0047] It should be noted that there are many common fitting algorithms. In this embodiment, the polynomial function fitting method is used to fit all reactive powers within the preset time period; in the actual application process, as other implementation manners, the implementer can also adopt other fitting methods such as the least square method, etc. Regarding the selection of the fitting method, this embodiment does not make special restrictions.

[0048] Among them, the polynomial function fitting is a well-known technology, and its specific principle will not be elaborated here.

[0049] Furthermore, the trend test algorithm is used to obtain the trend statistic of all active powers within a preset time period before the current moment, that is, the Z-value statistic, and the product of the range of all active powers within the preset time period and the trend statistic is used as the active power distribution value of the transmission line corresponding to the power grid section at the current moment.

[0050] It should be understood that as an implementation manner, in this embodiment, the Mann-Kendall trend test algorithm is used to obtain the trend statistic. In the actual application process, as other implementation manners, the implementer can also adopt other test methods such as the Kendall trend test algorithm according to the specific situation. Regarding the selection of the trend test algorithm, this embodiment does not make special restrictions.

[0051] Among them, the process of obtaining the trend statistic by using the Mann-Kendall trend test algorithm is a well-known technology, and its specific principle will not be elaborated here.

[0052] The energy acceptance degree of the transmission line corresponding to the power grid section at the current moment is the ratio of the active power distribution value to the dispersion degree of all peak amplitudes.

[0053] It should be noted that there are many common methods for measuring the dispersion degree of a group of data. In this embodiment, the variance of all peak amplitudes is used as the dispersion degree of all peak amplitudes. In the actual application process, as other implementation manners, the implementer can also adopt other methods for measuring the dispersion degree of data such as the standard deviation and the coefficient of variation. Regarding the selection of the method for measuring the dispersion degree of data, this embodiment does not make special restrictions.

[0054] It can be understood from the energy acceptance degree that the energy acceptance degree reflects the abnormal conditions of the transmission lines of the power grid section corresponding to the new energy grid-connected nodes in the power system with source-grid-load-storage coordination after the access of new energy power; the active power distribution value reflects the stable increase of the active power of the transmission lines of the power grid section after the access of new energy power; when the power system with source-grid-load-storage coordination has a higher acceptance degree for new energy power, the transmission lines of the power grid section can transport more power to meet the load demand of the power grid, and the active power distribution value becomes larger; under the influence of the randomness and volatility of the output of new energy power, the stronger the reactive power support ability of the transmission lines corresponding to the power grid section, the smaller the degree of reactive power fluctuation, and the smaller the dispersion degree of the wave peak and wave amplitude. Finally, the obtained energy acceptance degree is larger, indicating that the power grid system has a strong acceptance ability for new energy under the coordination of source-grid-load-storage, and the stability and reliability of the system are relatively high, and it can effectively support the access and utilization of large-scale new energy power;

[0055] On the contrary, if the energy acceptance degree is low, it means that the power grid system has a low acceptance degree for new energy power, and the active power distribution value becomes smaller, indicating that the power transmission capacity of the transmission lines of the power grid section is limited and cannot effectively meet the load demand, and there may be problems with the stability and distribution of the active power. The larger the dispersion degree of the wave peak and wave amplitude, the greater the degree of reactive power fluctuation, and the weaker the reactive power support ability of the power grid, which may lead to voltage instability and affect the safe and stable operation of the system.

[0056] So far, by analyzing the change trend and distribution of the active power, as well as the mutation degree of the reactive power, the energy acceptance degree has been obtained.

[0057] Step S3: Mark the moment corresponding to the negative active power as the reverse moment, compare the difference in active power between each reverse moment and the previous moment, determine the difference degree of the transmission lines corresponding to the power grid section at the current moment, and combine the dispersion degree of all power grid frequencies and the complexity of all power factors within the preset duration to determine the abnormality degree of the transmission lines corresponding to the power grid section at the current moment.

[0058] During the operation of the power system with source-grid-load-storage coordination, the grid-connected access of new energy power to the power system will not only cause changes in the active power and reactive power in the transmission lines of the power grid section, but also make the power grid section flow generate abnormal conditions; specifically, the intermittency and volatility of new energy power will lead to an increase in the power grid frequency fluctuation, and it is difficult to quickly restore the power grid frequency when the power grid regulation ability is insufficient; at the same time, the access of a high proportion of new energy power may cause the instability of the power grid section flow direction, making the power grid section flow direction reverse frequently, increasing the complexity and uncertainty of the power grid operation.

[0059] Based on the above analysis, the moment corresponding to the negative active power is recorded as the reverse moment. Compare the difference in active power between each reverse moment and the previous moment to determine the difference degree of the transmission line corresponding to the grid section at the current moment. Combine the dispersion degree of all grid frequencies and the complexity degree of all power factors within the preset time duration to determine the abnormality degree of the transmission line corresponding to the grid section at the current moment, which is used to characterize the abnormal tide of the grid section caused by the high proportion of energy power grid-connected access during the operation of the power system with source-network-load-storage coordination. The specific construction process of the abnormality degree is as follows:

[0060] In this embodiment, the moment corresponding to the negative active power is recorded as the reverse moment.

[0061] Furthermore, calculate the cumulative result of the difference in active power between all reverse moments and their previous moments within the preset time duration, and take the product of the cumulative result and the total number of reverse moments as the difference degree of the transmission line corresponding to the grid section at the current moment.

[0062] Furthermore, based on the difference degree of the transmission line corresponding to the grid section at the current moment and combining the dispersion degree of all grid frequencies and the complexity degree of all power factors within the preset time duration, determine the abnormality degree of the transmission line corresponding to the grid section at the current moment, specifically as follows:

[0063] The abnormality degree of the transmission line corresponding to the grid section at the current moment The expression is: ; In the formula, represents the difference degree of the transmission line corresponding to the grid section at the current moment; represents the standard deviation of all grid frequencies within the preset time duration; represents the fractal dimension of all power factors within the preset time duration; represents a constant greater than 0 preset to prevent the denominator from being 0, The value of is set artificially. In this embodiment,

[0064] the value of

[0065] is 0.01. On the premise of ensuring that the denominator is not 0 and does not overly affect the calculation result, the implementer can also set it according to the specific situation by himself. This embodiment does not make special restrictions.

[0066] According to the abnormality of the transmission line corresponding to the grid section at the current moment, it can be understood that the abnormality reflects the degree of abnormal reverse power flow caused by the high proportion of new energy access in the transmission line corresponding to the grid section in the power system with coordinated source, grid, load and storage; the difference represents the degree of reverse change of active power in the transmission line corresponding to the grid section; when the abnormal power flow condition of the grid section caused by the high proportion of new energy power access to the power system is more obvious, that is, the greater the abnormality, the greater the degree of reverse change of active power, and the greater the difference. When the fractal dimension of all power factors within the preset time is smaller, it means that in the power system with coordinated source, grid, load and storage, the degree of negative correlation of power factor in the transmission line corresponding to the grid section is more obvious, and the possibility of change in the flow direction of active power is greater. At this time, the more violent the networking frequency fluctuation of the transmission line corresponding to the grid section is, that is, the larger the standard deviation of all grid frequencies within the preset time, it means that the power system is more likely to be affected by the randomness and volatility of high proportion of new energy power.

[0067] On the contrary, when the abnormal power flow of the power grid section caused by the high proportion of new energy power access to the power system is not obvious, that is, when the abnormality is small, the smaller the degree of reverse change of active power, the smaller the difference. This means that the active power flow in the transmission line corresponding to the power grid section is relatively stable, the regulation ability and power flow control ability of the power system are good, and it can effectively cope with the impact of the access of new energy power. When the fractal dimension of all power factors within the preset time is larger, it means that in the power system with coordinated source, grid, load and storage, the degree of negative correlation of power factor in the transmission line corresponding to the power grid section is not obvious, and the possibility of change in the flow direction of active power is smaller. This shows that the power factor of the system is relatively stable and the operation state of the power grid is relatively healthy. The smoother the fluctuation of the interconnected frequency of the transmission line corresponding to the power grid section, that is, the smaller the standard deviation of all power grid frequencies within the preset time, indicates that the difference caused by the randomness and volatility of the high proportion of new energy power in the power system is reduced, and the frequency stability of the system is better.

[0068] So far, the abnormality degree is obtained by analyzing the difference of active power between adjacent moments, the discreteness of the grid frequency and the complexity of the power factor.

[0069] Step S4: Based on the energy acceptance and the abnormality, determine the energy consumption of the transmission line corresponding to the grid section at the current moment; measure the difference between the load rate of all lines within the preset time period and the preset heavy load rate, as well as the difference in line loss between each moment and the previous moment, determine the loss degree, and combine the energy consumption to determine the power supply degree of the transmission line corresponding to the grid section at the current moment.

[0070] In a power system with coordinated source-network-load-storage, the higher the energy acceptance degree of the transmission lines corresponding to the grid section and the milder the abnormal condition of the section power flow, it indicates that the abnormal condition of the transmission lines of the grid section corresponding to the new energy grid connection nodes after the access of new energy power is milder, the reverse abnormal degree of power Charlie is smaller, and the grid section is at a higher level of new energy power consumption.

[0071] Therefore, based on the energy acceptance degree and the abnormal degree, determine the energy consumption degree of the transmission lines corresponding to the grid section at the current moment, which is used to characterize the power consumption level of the power system with coordinated source-network-load-storage after the connection of new energy. The specific construction method is as follows:

[0072] The energy consumption degree of the transmission lines corresponding to the grid section at the current moment The expression is: ; In the formula, represents the energy acceptance degree of the transmission lines corresponding to the grid section at the current moment; represents the abnormal degree of the transmission lines corresponding to the grid section at the current moment; norm( ) represents the normalization function; represents a preset constant greater than 0, which is used to prevent the denominator from being 0, The value of is set manually. In this embodiment, the value of

[0073] is 0.01. On the premise of ensuring that the denominator is not 0 and does not overly affect the calculation result, the implementer can also set it according to the specific situation by himself. This embodiment does not make special restrictions.

[0073] According to the energy consumption degree, it can be understood that the energy consumption degree reflects the power consumption level of the power system with coordinated source-network-load-storage for the accessed new energy power. When the energy consumption degree is larger, the power system has a higher power consumption level for the accessed new energy power, that is, the energy acceptance degree is larger, and the active power output condition of the new energy in the transmission lines corresponding to the grid section is more obvious, the reactive power support ability is stronger, and the reverse change of the power flow is milder, that is, the abnormal degree is smaller; on the contrary, if the energy consumption degree is smaller, that is, the power system has a lower power consumption level for the accessed new energy power, this means that the power system may not be able to effectively utilize new energy power generation, which may lead to the incomplete absorption of new energy power by the grid. The corresponding energy acceptance degree is smaller, indicating that the power system has a weak acceptance ability for new energy, which may be restricted by factors such as grid structure, dispatching strategy, energy storage capacity or load characteristics and cannot fully accept new energy power; and the active power output condition of the new energy in the transmission lines corresponding to the grid section is not obvious, that is, the abnormal degree is larger, which may indicate that the proportion of new energy power in the grid is not high, or the volatility and uncertainty of new energy power generation have a greater impact on the grid.

[0074] Furthermore, during the operation of a power system with coordinated source-network-load-storage, due to the strong randomness and volatility of new energy power generation, when it is connected to the power system and the system's regulation ability is insufficient, the problem of "channel grabbing" between conventional energy and new energy may occur. This can lead to damage to the grid stability and exacerbate the scheduling pressure of conventional power. Specifically, the situation of "channel grabbing" between conventional energy and new energy power will cause an increase in the current in the transmission line, thereby increasing the active power loss of each grid section in the power system, that is, the situation of increasing line loss of the transmission line corresponding to the grid section becomes more and more serious.

[0075] Based on the above analysis, by measuring the difference between all line load rates and the preset heavy load rate within the preset time period, and the difference in line loss between each moment and its previous moment, the loss degree is determined to characterize the upward trend of line loss caused by "channel grabbing" between conventional energy and new energy during the operation of a power system with coordinated source-network-load-storage. The specific determination process of the loss degree is as follows:

[0076] The loss degree of the transmission line corresponding to the grid section at the current moment The expression is: ; In the formula, represents the cumulative sum of the differences between all line load rates and the preset heavy load rate within the preset time period; represents the difference in line loss between moment i and its previous moment within the preset time period; I represents the number of all moments within the preset time period; exp( ) represents the exponential function with the natural constant as the base.

[0077] Among them, the value of the preset heavy load rate is set artificially. In this embodiment, the value of the preset heavy load rate is 0.8. Implementers can also set it according to specific situations, and this embodiment does not make special restrictions.

[0078] Particularly, to prevent the calculation result of f from being negative due to the daily line load rate not exceeding the preset heavy load rate, when the cumulative result of the difference between all line load rates and the heavy load rate within any day is negative, the calculation result of f is recorded as 1.

[0079] From the loss degree of the transmission line corresponding to the grid section at the current moment, it can be understood that the loss degree reflects the situation of increasing line loss caused by the "channel grabbing" between conventional energy and new energy; the cumulative sum f of the differences between all line load rates and the preset heavy load rate within the preset time period characterizes the heavy load degree of the line load rate during the operation of a power system with coordinated source-network-load-storage; when the "channel grabbing" situation between conventional energy and new energy caused by the access of new energy to the power system is more serious, the heavy load situation of the line load is more obvious, that is, the loss degree is greater. Therefore, the calculation index f becomes larger, the trend of increasing line loss is more obvious, and the difference in line loss between moment i and its previous moment within the preset time period becomes larger;

[0080] Conversely, when the situation of "channel competition" between conventional energy and new energy caused by the access of new energy to the power system is not serious, the heavy load situation of the line is not obvious, that is, the loss degree is smaller: this means that the load rate of the line remains at a relatively reasonable level, and there is no serious overload phenomenon. Therefore, the line loss is relatively low. At this time, the cumulative sum f of the differences between the load rates of all lines and the preset heavy load rate within the preset time period becomes smaller, indicating that the operating state of the line is healthier and there is no obvious heavy load risk; the difference in line loss between time i and its previous moment within the preset time period becomes smaller, which indicates that the line loss is relatively stable and there is no large fluctuation, and the power grid operation is more stable.

[0081] Furthermore, when the power system of the source-grid-load-storage system has a stronger ability to absorb the new energy power connected, and the situation of "channel competition" between conventional energy and new energy caused is milder, the regulation ability of the source-grid-load-storage coordinated power system is stronger, and the power supply degree of the power system after connecting a high proportion of new energy power is higher.

[0082] Therefore, based on the loss degree and combined with the energy consumption degree, the power supply degree of the transmission line corresponding to the power grid section at the current moment is determined, which is used to characterize the operation balance situation of the power system after connecting a high proportion of new energy power during the operation of the source-grid-load-storage coordinated power system. The specific construction method is as follows:

[0083] In this embodiment, the power supply degree of the transmission line corresponding to the power grid section at the current moment is the normalized result of the ratio of the energy consumption degree to the loss degree of the line corresponding to the power grid section at the current moment; the larger the ratio of the energy consumption degree to the loss degree, the higher the power supply degree, indicating that the power system has a stronger ability to absorb new energy power during the source-grid-load-storage coordination process, and the situation of "channel competition" between conventional energy and new energy is milder. On the contrary, the smaller the ratio of the energy consumption degree to the loss degree, the lower the power supply degree, indicating that the power system has a weaker ability to absorb new energy power during the source-grid-load-storage coordination process.

[0084] So far, by analyzing the difference between the energy consumption degree and the loss degree, the power supply degree is obtained.

[0085] Preferably, the schematic diagram of the power supply degree extraction process provided in this embodiment is as Figure 2 shown.

[0086] Step S5: Based on the power supply degree, to judge the necessity of power dispatching during the dispatching optimization process of the new power system at the current moment.

[0087] Based on the power supply degree obtained in step S4, further, a preset threshold is set. If the power supply degree of the transmission line corresponding to the power grid section at the current moment is greater than or equal to the preset threshold, it is considered that the power supply degree of the transmission line corresponding to the current power grid section is strong, the power system has a strong ability to absorb high-proportion new energy power, and the phenomenon of "channel grabbing" between conventional energy and new energy is slight, and there is no need to perform power dispatching on the power grid at the current moment; otherwise, if the power supply degree of the transmission line corresponding to the power grid section at the current moment is less than the preset threshold, it is considered that the power supply degree of the transmission line corresponding to the current power grid section is poor, the power system cannot normally absorb the accessed new energy power resources, and due to the serious power difference caused by the randomness and volatility of new energy power, the phenomenon of "channel grabbing" between conventional energy and new energy intensifies, then power dispatching needs to be performed on the power grid at the current moment.

[0088] In the power system of the source-network-load-storage system, based on ensuring the full absorption of the maximum output of new energy power, according to the power balance status of the power system, the adjustment capacity of the controllable user load of electricity is adjusted, and based on this, the charging and discharging state quantities of the energy storage system are controlled to achieve the power balance of the entire power system, effectively reducing the load fluctuation and the operation cost of the power system.

[0089] It should be noted that the value of the preset threshold is set artificially. In this embodiment, the value of the preset threshold is 0.6. In the actual application process, the implementer can also set it according to the specific situation by himself / herself, and this embodiment does not make special restrictions.

[0090] It should be noted that: the above order of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the above describes specific embodiments of this specification. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be beneficial.

[0091] Each embodiment in this specification is described in a progressive manner. For the same or similar parts between each embodiment, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments.

[0092] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; modifying the technical solutions recorded in the foregoing embodiments, or equivalently replacing some of the technical features, does not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of each embodiment of the present application, and should all be included in the protection scope of the present application.

Claims

1. A novel power system optimal dispatching method for source-network-load-storage coordination, characterized in that, The method includes the following steps: Collect in real time the active power, reactive power, power factor, grid frequency, line load rate, and line loss of the transmission lines corresponding to the grid section in the new power system; Fit all the reactive powers within a preset time period before the current moment, analyze the differences between the peaks and their nearest valleys on the fitting curve, and determine the amplitudes of the peaks; analyze the change trend and extreme distribution of all the active powers within the preset time period, determine the active power distribution value of the transmission lines corresponding to the grid section at the current moment, and combine the dispersion degree of the amplitudes of all the peaks to determine the energy acceptance degree of the transmission lines corresponding to the grid section at the current moment; Mark the moments when the active power is negative as reverse moments, compare the differences in active power between each reverse moment and its previous moment, determine the difference degree of the transmission lines corresponding to the grid section at the current moment, and combine the dispersion degree of all the grid frequencies and the complexity degree of all the power factors within the preset time period to determine the abnormality degree of the transmission lines corresponding to the grid section at the current moment; Based on the energy acceptance degree and the abnormality degree, determine the energy consumption degree of the transmission lines corresponding to the grid section at the current moment; measure the difference between all the line load rates and the preset heavy load rate within the preset time period, and the difference in line loss between each moment and its previous moment, determine the loss degree, and combine the energy consumption degree to determine the power supply degree of the transmission lines corresponding to the grid section at the current moment; Based on the power supply degree, judge the necessity of power dispatching in the process of dispatching optimization of the new power system at the current moment.

2. The novel power system optimal dispatching method for source-network-load-storage coordination according to claim 1, wherein, The amplitude of each peak is the absolute difference between the peak value of each peak and the valley value of its nearest valley.

3. The novel power system optimal dispatching method for source-network-load-storage coordination according to claim 1, wherein, The method for determining the active power distribution value of the transmission lines corresponding to the grid section at the current moment is as follows: Adopt a trend test algorithm to obtain the trend statistic of all the active powers within a preset time period before the current moment, and take the product of the range of all the active powers within the preset time period and the trend statistic as the active power distribution value of the transmission lines corresponding to the grid section at the current moment.

4. The novel power system optimal scheduling method for source-network-load-storage coordination according to claim 1, wherein, The energy acceptance degree of the transmission lines corresponding to the grid section at the current moment is the ratio of the active power distribution value to the dispersion degree of all the peak amplitudes.

5. The novel power system optimal dispatching method for source-network-load-storage coordination according to claim 1, wherein, The method for determining the difference degree of the transmission lines corresponding to the grid section at the current moment is as follows: Calculate the cumulative result of the differences in active power between all the reverse moments and their previous moments within the preset time period, and take the product of the cumulative result and the total number of reverse moments as the difference degree of the transmission lines corresponding to the grid section at the current moment.

6. The novel power system optimal scheduling method for source-network-load-storage coordination according to claim 1, characterized in that, The expression for the abnormality degree of the transmission line corresponding to the power grid section at the current moment is as follows: ; In the formula, represents the abnormality degree of the transmission line corresponding to the power grid section at the current moment; represents the difference degree of the transmission line corresponding to the power grid section at the current moment; represents the standard deviation of all power grid frequencies within the preset duration; represents the fractal dimension of all power factors within the preset duration; represents a constant greater than 0 preset.

7. The novel power system optimal scheduling method for source-network-load-storage coordination according to claim 1, wherein, The expression for the energy consumption degree of the transmission line corresponding to the power grid section at the current moment is as follows: ; In the formula, represents the energy consumption degree of the transmission line corresponding to the power grid section at the current moment; represents the energy acceptance degree of the transmission line corresponding to the power grid section at the current moment; represents the abnormality degree of the transmission line corresponding to the power grid section at the current moment; norm( ) represents the normalization function; represents a preset constant greater than 0.

8. The novel power system optimal scheduling method for source-network-load-storage coordination according to claim 1, characterized in that, The expression for the loss degree is as follows: ; where represents the loss degree of the transmission line corresponding to the power grid section at the current moment; represents the cumulative sum of the differences between the load rates of all lines and the preset heavy load rate within the preset time period; represents the difference in line loss between the moment i and the previous moment within the preset time period; I represents the number of all moments within the preset time period; exp( ) represents the exponential function with the natural constant as the base.

9. The novel power system optimal scheduling method for source-network-load-storage coordination according to claim 1, characterized in that The power supply degree of the transmission lines corresponding to the grid section at the current moment is the normalized result of the ratio of the energy consumption degree to the loss degree of the lines corresponding to the grid section at the current moment.

10. The novel power system optimal scheduling method for source-network-load-storage coordination according to claim 1, wherein, The judgment of the necessity of power dispatching in the process of dispatching optimization of the new power system at the current moment includes: If the power supply degree of the transmission lines corresponding to the grid section at the current moment is greater than or equal to the preset threshold, then there is no need to perform power dispatching on the grid at the current moment; otherwise, power dispatching on the grid at the current moment is required.

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