Source-grid-load-storage-coordinated novel power system optimization scheduling method

Abstract

The invention relates to the technical field of power system collaborative optimization scheduling, in particular to a novel power system optimization scheduling method with source-grid-load-storage collaboration, and the method comprises the steps: analyzing the change trend and extreme distribution of active power, and determining the energy acceptance degree in combination with the dispersion degree of the amplitude of all wave crests; comparing the difference of the active power between each reverse moment and the previous moment, and combining the dispersion degree of the power grid frequency and the complexity of all power factors to determine the abnormality; and determining an energy consumption degree based on the energy acceptance degree and the abnormality degree, and determining a power supply degree in combination with the difference between the load rates of all lines and a preset heavy load rate in a preset time length to judge the necessity of power dispatching. According to the invention, defects caused by new energy power access of the power system can be rapidly evaluated and rapidly adjusted and adapted, the adjustment flexibility of the power system is improved, and reliable power supply is guaranteed.

Description

Technical Field

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

[0002] Source-grid-load-storage coordination refers to the organic integration and coordinated 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 dispatching 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. However, the existing technology has a relatively coarse monitoring granularity for key parameters such as the power flow of the grid section, voltage, and frequency, and cannot 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 dispatching method for source-grid-load-storage coordination to solve the existing problems.

[0005] The new power system optimization dispatching method for source-grid-load-storage coordination of this application adopts the following technical solutions: An embodiment of this application provides a new power system optimization dispatching method for source-grid-load-storage coordination, and this method includes the following steps: 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; 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 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; The moments corresponding to negative active power are recorded as reverse moments. Compare the differences in active power between each reverse moment and the previous moment to determine the difference degree of the transmission lines 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 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 line load rates and the preset heavy load rate within the preset time duration, and the difference in line losses between each moment and the previous moment to determine the loss degree. 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 dispatching optimization process of the new power system at the current moment.

[0006] 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 valley.

[0007] 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: Use the trend test algorithm to obtain the trend statistic of all active powers within the preset time duration before the current moment. Multiply the range of all active powers within the preset time duration by the trend statistic as the active power distribution value of the transmission lines corresponding to the grid section at the current moment.

[0008] 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.

[0009] Preferably, 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 reverse moments and the previous moment within the preset time duration. Multiply the cumulative result by the total number of reverse moments as the difference degree of the transmission lines corresponding to the grid section at the current moment.

[0010] 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 time duration; represents the fractal dimension of all power factors within the preset time duration; represents a preset constant greater than 0.

[0011] Preferably, the expression for the energy consumption degree of the transmission line corresponding to the power grid section at the current moment is: ; where 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.

[0012] Preferably, the expression for the loss degree is: ; 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 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.

[0013] Preferably, 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.

[0014] Preferably, determining 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 line corresponding to the power 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 power grid at the current moment; otherwise, power dispatching on the power grid at the current moment is required.

[0015] This application has at least the following beneficial effects: 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 achieve 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

[0016] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the description of the embodiments or the prior art will be briefly introduced below. 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.

[0017] Figure 1 It is a flowchart of the steps of a novel power system optimal dispatching method with source-network-load-storage coordination provided by an embodiment of the present application; Figure 2 It is a schematic diagram of the power supply degree extraction process provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to further elaborate on the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following combines the drawings and preferred embodiments to detail the specific implementation manners, structures, features and effects of the novel power system optimal dispatching 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.

[0019] 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.

[0020] The following specifically describes the specific solution of the new power system optimal dispatching method for source-grid-load-storage coordination provided by this application in combination with the accompanying drawings.

[0021] A new power system optimal dispatching method for source-grid-load-storage coordination provided by an embodiment of this application. Specifically, the following new power system optimal dispatching method for source-grid-load-storage coordination is provided. Please refer to Figure 1 , and the method includes the following steps: 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 new power system.

[0022] 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 source-grid-load-storage coordinated power system, 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, and obtain the relevant parameters of the transmission lines and transformers, as well as the rated parameters of 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.

[0023] Perform power flow calculations through the above-obtained data, 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 new power system, and set the data collection frequency to q.

[0024] 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.

[0025] It should be added that the value of the data collection frequency q is 10Hz. Implementers can also set it according to specific circumstances, and this embodiment does not make special restrictions.

[0026] Transmit the above-obtained data to the data collection system of the power system by means of fiber optic private network or wireless communication, synchronize its timestamp using GPS clock synchronization technology 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.

[0027] It should be noted that there are many common normalization methods. In this embodiment, the z-score normalization method is used to process the collected data. In actual application processes, implementers can also use other normalization methods such as the maximum-minimum normalization method. Regarding the selection of the normalization method, this embodiment does not make special restrictions.

[0028] Among them, the z-score normalization method is a well-known technology, and its specific principle will not be elaborated here.

[0029] Step S2: 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 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.

[0030] During the operation of a power system with source-grid-load-storage coordination, due to the strong randomness and volatility of the output of new energy power, the intervention of a high proportion of new energy power may cause severe fluctuations in the power flow of the grid section corresponding to the new energy power grid connection node. When the power system cannot accurately monitor the consumption capacity of new energy power, it is difficult to effectively match the grid load demand with new energy generation, increasing the difficulty of power system peak shaving and frequency modulation. In severe cases, it may even pose a risk of supply-demand imbalance.

[0031] Specifically, when the power system with source-grid-load-storage coordination has a stronger consumption capacity for new energy power, the power system has a higher acceptance degree for the randomness and volatility of new energy. The transmission line can deliver more new energy power to meet the grid load demand, that is, the increase in the active power of the transmission line at the grid section is more stable, and the reactive power support ability at the grid section is stronger. The support effect of the reactive power compensation devices installed in the power system, such as SVC and SVG, on voltage stability makes the random volatility of reactive power less significant.

[0032] Therefore, based on the above analysis, 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 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, which is used to characterize the consumption capacity of the power system for new energy power and the "channel grabbing situation" between conventional energy and new energy. The specific construction process of the energy acceptance degree is as follows: As an implementation, 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 trough is used as the amplitude of each peak; among them, the absolute difference means taking the absolute value of the difference.

[0033] 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. Implementers can also set it by themselves according to specific situations, and this embodiment does not make special restrictions.

[0034] 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 implementations, implementers can also use other fitting methods such as the least squares method. Regarding the selection of the fitting method, this embodiment does not make special restrictions.

[0035] Among them, polynomial function fitting is a well-known technology, and its specific principle will not be elaborated here.

[0036] 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 grid section at the current moment.

[0037] It should be understood that, as an implementation, in this embodiment, the Mann-Kendall trend test algorithm is used to obtain the trend statistic. In the actual application process, as other implementations, implementers can also use other test methods such as the Kendall trend test algorithm according to specific situations. Regarding the selection of the trend test algorithm, this embodiment does not make special restrictions.

[0038] Among them, the process of using the Mann-Kendall trend test algorithm to obtain the trend statistic is a well-known technology, and its specific principle will not be elaborated here.

[0039] The energy acceptance degree of the transmission line corresponding to the grid section at the current moment is the ratio of the active power distribution value to the dispersion degree of all peak amplitudes.

[0040] It should be noted that there are many common methods for measuring the dispersion degree of a set 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 implementations, implementers can also use 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.

[0041] It can be understood from the energy acceptance that the energy acceptance reflects the abnormal conditions of the transmission lines of the grid section corresponding to the new energy grid connection nodes in the power system with coordinated source-grid-load-storage 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 grid section after the access of new energy power; when the energy acceptance of the power system with coordinated source-grid-load-storage for new energy power is higher, the transmission lines of the grid section can deliver more power to meet the grid load demand, and the active power distribution value becomes larger; under the influence of the randomness and volatility of new energy power output, the stronger the reactive power support ability of the transmission lines corresponding to the grid section, the smaller the reactive power fluctuation degree, and the smaller the dispersion degree of the wave peak and wave amplitude. Finally, the obtained energy acceptance is larger, indicating that the 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, which can effectively support the access and utilization of large-scale new energy power. On the contrary, if the energy acceptance is low, it means that the grid system has a low acceptance degree for new energy power, the active power distribution value becomes smaller, indicating that the power transmission capacity of the transmission lines of the 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 dispersion degree of the wave peak and wave amplitude indicates a larger reactive power fluctuation degree and a weaker reactive power support ability of the grid, which may lead to voltage instability and affect the safe and stable operation of the system.

[0042] So far, the energy acceptance has been obtained by analyzing the change trend and distribution of the active power, as well as the mutation degree of the reactive power.

[0043] Step S3: Denote the moment when the active power is negative 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 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.

[0044] During the operation of the power system with coordinated source-grid-load-storage, the grid connection 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 grid section, but also make the grid section power flow have abnormal conditions; specifically, the intermittency and volatility of new energy power will lead to an increase in grid frequency fluctuations, and it is difficult to quickly restore the grid frequency when the grid regulation ability is insufficient; at the same time, the access of a high proportion of new energy power may cause instability in the power flow direction of the grid section, resulting in frequent reversals of the power flow direction of the grid section, increasing the complexity and uncertainty of grid operation.

[0045] Based on the above analysis, the moment corresponding to 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 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 abnormality of the grid section power flow caused by the high proportion of energy and power grid-connected access during the operation of the source-network-load-storage coordinated power system. The specific construction process of the abnormality degree is as follows: In this embodiment, the moment corresponding to negative active power is recorded as the reverse moment.

[0046] Furthermore, calculate the cumulative result of the difference in active power between all reverse moments and their previous moments within the preset 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.

[0047] 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 duration, determine the abnormality degree of the transmission line corresponding to the grid section at the current moment, specifically: 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 duration; represents the fractal dimension of all power factors within the preset duration; represents a constant greater than 0 preset to prevent the denominator from being 0, The value of is set artificially. In this embodiment,

[0048] the value of

[0049] 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.

[0050] It should be noted that there are many calculation methods for the fractal dimension. In this implementation, the Hurst exponent is used to calculate the fractal dimension. In the actual application process, the implementer can also use the box-counting method to calculate the fractal dimension. Regarding the selection of the fractal dimension calculation method, this embodiment does not make special restrictions.

[0049] Among them, the Hurst exponent is a well-known technology, and its specific principle will not be elaborated here.

[0050] 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. 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.

[0051] 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.

[0052] 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.

[0053] In a power system with source-network-load-storage coordination, 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, the milder the abnormal condition of the transmission lines corresponding to the grid section where the new energy grid-connected nodes are located after the access of new energy power, the smaller the reverse abnormal degree of the power flow, and the higher the consumption level of the new energy power in the grid section.

[0054] Therefore, based on the energy acceptance degree and the abnormal degree, the energy consumption degree of the transmission lines corresponding to the grid section at the current moment is determined, which is used to characterize the power consumption level of the power system with source-network-load-storage coordination after the grid connection of new energy. The specific construction method is as follows: 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

[0055] 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.

[0055] 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 source-network-load-storage coordination for the accessed new energy power. When the energy consumption degree is larger, the power consumption level of the power system for the accessed new energy power is higher, 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; conversely, if the energy consumption degree is smaller, that is, the power consumption level of the power system for the accessed new energy power is lower, which means that the power system may not be able to effectively utilize new energy power generation, may cause the new energy power to not be fully absorbed by the grid, the corresponding energy acceptance degree is smaller, indicating that the power system has a weak acceptance ability for new energy, and 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.

[0056] 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 output, 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 power grid stability and increased dispatching pressure on 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 power grid section in the power system, that is, the situation of increasing line loss corresponding to the transmission line of the power grid section becomes more and more serious.

[0057] 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 the previous moment, the loss degree is determined, which is used 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: The loss degree of the transmission line corresponding to the power 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 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.

[0058] 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 by themselves, and this embodiment does not make special restrictions.

[0059] Specifically, 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.

[0060] It can be understood from the loss degree of the transmission line corresponding to the power grid section at the current moment 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 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 the previous moment within the preset time period becomes larger; Conversely, when the situation of "channel grabbing" between conventional energy and new energy caused by the access of new energy to the power system is not serious, the heavy load condition 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 without serious overload. 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, indicating that the line loss is relatively stable without large fluctuations and the power grid operation is more stable.

[0061] Furthermore, when the power system of the source-grid-load-storage system has a stronger ability to absorb the new energy power accessed, and the situation of "channel grabbing" 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 accessing a high proportion of new energy power is higher.

[0062] Therefore, based on the loss degree and combined with the energy consumption degree, the power supply degree of the transmission line corresponding to the grid section at the current moment is determined, which is used to characterize the operation balance condition of the power system after accessing 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: In this embodiment, 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. 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 grabbing" between conventional energy and new energy is milder. Conversely, 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.

[0063] So far, by analyzing the difference between the energy consumption degree and the loss degree, the power supply degree is obtained.

[0064] Preferably, the schematic diagram of the power supply degree extraction process provided in this embodiment is as Figure 2 shown.

[0065] 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.

[0066] 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; on the contrary, 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 it is necessary to perform power dispatching on the power grid at the current moment.

[0067] 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 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 accordingly to achieve the power balance of the entire power system and effectively reduce the load fluctuation and the operation cost of the power system.

[0068] 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 by combining specific situations, and this embodiment does not make special restrictions.

[0069] It should be noted that: the above sequence 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 specific embodiments of this specification have been described. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be beneficial.

[0070] 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.

[0071] 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 within the protection scope of the present application.

Claims

1. A new power system optimization dispatching method with source-grid-load-storage coordination, characterized by: The method comprises the following steps: Real-time collection of 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; 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; The moment corresponding to the negative active power is recorded as the reverse moment, and the difference in active power between each reverse moment and the previous moment is compared to determine the difference of the power transmission line corresponding to the power grid section at the current moment, and the abnormality of the power transmission line corresponding to the power grid section at the current moment is determined in combination with the discrete degree of all power grid frequencies and the complexity of all power factors within the preset time length; 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, and the difference between the line loss at each moment and the previous moment, determine the loss degree, and determine the power supply degree of the transmission line corresponding to the grid section at the current moment in combination with the energy consumption; Based on the power supply degree, the necessity of power dispatch in the new power system dispatch optimization process at the current moment is judged.

2. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The amplitude of each wave crest is the absolute difference between the peak value of each wave crest and the valley value of its nearest valley.

3. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The method for determining the active power distribution value of the transmission line corresponding to the grid section at the current moment is: A trend test algorithm is used to obtain the trend statistics of all active power within a preset time period before the current moment, and the product of the range of all active power within the preset time period and the trend statistics is used as the active distribution value of the transmission line corresponding to the grid section at the current moment.

4. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The energy acceptance degree of the power transmission line corresponding to the power grid section at the current moment is the ratio of the active power distribution value to the discrete degree of all wave peak amplitudes.

5. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The method for determining the difference between the power grid section and the transmission line at the current moment is: The accumulated result of the active power difference between all the reverse moments within the preset time period and the previous moment is calculated, and the product of the accumulated result and the total number of reverse moments is used as the difference degree of the power transmission line corresponding to the grid section at the current moment.

6. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The expression of the abnormality of the power transmission line corresponding to the power grid section at the current moment is: ; In the formula, Indicates the abnormality of the transmission line corresponding to the power grid section at the current moment; Indicates the difference between the power grid section and the corresponding transmission line at the current moment; Represents the standard deviation of all power grid frequencies within the preset time period; A fractal dimension representing all power factors within the preset time period; Indicates a preset constant greater than 0.

7. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The expression of the energy consumption of the power transmission line corresponding to the power grid section at the current moment is: ; In the formula, Indicates the energy consumption of the power transmission line corresponding to the power grid section at the current moment; Indicates the energy acceptance of the power grid section corresponding to the transmission line at the current moment; It indicates the abnormality of the transmission line corresponding to the power grid section at the current moment; norm() indicates the normalization function; Indicates a preset constant greater than 0.

8. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The expression of the loss degree is: ; In the formula, Indicates the loss degree of the transmission line corresponding to the grid section at the current moment; represents the cumulative sum of the differences between the load rates of all lines and the preset overload rate within the preset time period; represents the difference in line loss between moment i and its previous moment within the preset time length; I represents the number of all moments within the preset time length; exp() represents an exponential function with a natural constant as the base.

9. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1 is characterized in that: The power supply degree of the power 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.

10. The novel power system optimization dispatching method with source-grid-load-storage coordination as claimed in claim 1, characterized in that: The necessity of power dispatching in the dispatch optimization process of the new power system at the current moment is determined, including: 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, there is no need to perform power dispatch on the grid at the current moment; otherwise, there is a need to perform power dispatch on the grid at the current moment.

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