Power system multistage section safety boundary fitting method and system

Abstract

The invention discloses a multi-stage section safety boundary fitting method and system for a power system. The method comprises the following steps: constructing a safety boundary linear constraint condition; substituting a section limit combination mode in the dispatching sheet into the safety boundary linear constraint condition, sequentially selecting any section combination as a reference mode, obtaining a section power difference equation of all the section combinations and the reference mode, and solving a coupling coefficient based on the power difference equation to obtain a section coupling coefficient corresponding to each reference mode; averaging the section coupling coefficients corresponding to all the reference modes to obtain an average section coupling coefficient; and substituting the average section coupling coefficient into the safety boundary linear constraint condition, checking and correcting the coupling coefficient based on the safety margin, obtaining the section coupling coefficient meeting the safety boundary, and realizing multi-stage section safety boundary fitting. The energy utilization efficiency can be improved while safe and stable operation of the power system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of power system operation, and more specifically, to a method and system for fitting multi-level section safety boundaries of a power system. Background Art

[0002] Large-scale renewable energy units are gradually replacing conventional thermal power generating units in the power system. The uncertainty of renewable energy output and the uneven distribution of time and space have aggravated the power grid trend. When faced with disturbances, there is a high risk of safe operation, which brings challenges to the safe operation of the power system. In order to ensure the safe and stable operation of the power grid, the upper limit of the transmission power of important transmission sections will be limited when arranging the operation mode, that is, the safety constraint boundary will be set for the AC section. At the same time, in order to ensure the stable delivery of renewable energy electricity, DC transmission projects have been put into operation one after another. The operation mode of the new power system has become more and more complex and changeable, the safety boundary of the system is unclear, and the multi-level section limit is difficult to formulate, making the planning and operation management of the power system more difficult.

[0003] The existing safety boundaries of power system operation modes are mostly evaluated based on expert experience, and the section operation limits mainly rely on the manually formulated operation mode adjustment orders. As the operation mode of the power system becomes more and more changeable, the original section limit combination of the adjustment order can no longer meet the daily operation needs. The correlation between the safety boundary and the section limits is difficult to clarify, and the contradiction between the large-scale transmission demand of new energy and the system safety is prominent. Therefore, it is necessary to fit the safety boundary based on the existing multi-level section limits to deal with the safety risks brought about by the changeable operation mode.

[0004] Therefore, a method for fitting the safety margin of multi-level sections in power systems is needed. Summary of the invention

[0005] The present invention provides a multi-level section safety boundary fitting method and system for a power system, so as to solve the problem of how to determine the multi-level section safety boundary.

[0006] In order to solve the above problem, according to one aspect of the present invention, a method for fitting multi-level section safety margins of a power system is provided, the method comprising:

[0007] Construct safety boundary linear constraints;

[0008] Substitute the section limit combination method in the adjustment order into the safety boundary linear constraint condition, select any section combination as the reference method in turn, obtain the section power difference equation of all section combinations and the reference method, and calculate the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference method;

[0009] The cross-sectional coupling coefficients corresponding to all the benchmark methods are averaged to obtain the average cross-sectional coupling coefficient;

[0010] The average cross-section coupling coefficient is introduced into the safety boundary linear constraint condition, and the coupling coefficient is checked and corrected based on the safety margin to obtain the cross-section coupling coefficient that meets the safety boundary, thereby realizing multi-level cross-section safety boundary fitting.

[0011] Preferably, the step of constructing a safety boundary linear constraint condition comprises:

[0012] Each section is taken as a dimension, and multiple sections in the area constitute a multidimensional coordinate system. A set of multi-level section power limits corresponds to a mapping value that reflects the safety domain. The power of each section and the system safety and stability level are taken as independent variables and dependent variables respectively, and inequality safety constraints are constructed to obtain safety boundary constraints.

[0013] Preferably, the inequality safety constraint condition is: Where i = 1, 2, ..., m, m is the number of sections, P is the active power of the i-th section, k i is the coupling coefficient of the i-th section, ε is the safety margin;

[0014] The safety boundary constraints are: Among them, P i up is the power limit of the i-th section.

[0015] Preferably, the step of sequentially selecting any one section combination as a reference mode, obtaining the section power difference equations of all section combinations and the reference mode, and calculating the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode comprises:

[0016] For any reference method, the safety boundary equation constraints corresponding to all methods of the adjustment order are subtracted from the safety boundary constraint equations corresponding to the reference method to obtain a power difference equation group, and m-1 equations are selected from the power difference equations and solved to obtain a set of coupling coefficient solutions. The cross-section coupling coefficient solutions are obtained for each case; where m is the number of cross-sections; N is the number of cross-section limit combinations;

[0017] The obtained coupling coefficient solutions are evaluated and screened, and feasible solutions that meet the actual operation requirements are retained. The average of the screened coupling coefficient solutions is calculated to obtain the cross-section coupling coefficient corresponding to the benchmark method.

[0018] Preferably, the average cross-section coupling coefficient is brought into the safety boundary linear constraint condition, the coupling coefficient is checked and corrected based on the safety margin, the cross-section coupling coefficient that satisfies the safety boundary is obtained, and multi-level cross-section safety boundary fitting is realized, including:

[0019] Substituting the average cross-section coupling coefficient into the safety boundary linear constraint condition, obtaining the average value of N safety margin fitting values; wherein N is the number of cross-section limit combinations;

[0020] The coupling coefficients of each section are scaled exponentially based on the degree of deviation of the safety margin fitting average value relative to the original safety margin to obtain the section coupling coefficient that meets the safety boundary, thereby realizing multi-level section safety boundary fitting.

[0021] According to another aspect of the present invention, a multi-level section safety boundary fitting system for a power system is provided, the system comprising:

[0022] Constraint building unit, used to build safety boundary linear constraints;

[0023] A section coupling coefficient determination unit is used to substitute the section limit combination mode in the adjustment order into the safety boundary linear constraint condition, select any section combination as the reference mode in turn, obtain the section power difference equation of all section combinations and the reference mode, and calculate the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode;

[0024] The average cross-sectional coupling coefficient determination unit is used to average the cross-sectional coupling coefficients corresponding to all reference modes to obtain the average cross-sectional coupling coefficient;

[0025] The correction unit is used to bring the average cross-section coupling coefficient into the safety boundary linear constraint condition, perform verification and correction of the coupling coefficient based on the safety margin, obtain the cross-section coupling coefficient that meets the safety boundary, and realize multi-level cross-section safety boundary fitting.

[0026] Preferably, the constraint condition construction unit constructs the safety boundary linear constraint condition, including:

[0027] Each section is taken as a dimension, and multiple sections in the area constitute a multidimensional coordinate system. A set of multi-level section power limits corresponds to a mapping value that reflects the safety domain. The power of each section and the system safety and stability level are taken as independent variables and dependent variables respectively, and inequality safety constraints are constructed to obtain safety boundary constraints.

[0028] Preferably, the inequality safety constraint condition is: Where i = 1, 2, ..., m, m is the number of sections, P is the active power of the i-th section, k i is the coupling coefficient of the i-th section, ε is the safety margin;

[0029] The safety boundary constraints are: Among them, P i up is the power limit of the i-th section.

[0030] Preferably, the section coupling coefficient determination unit sequentially selects any section combination as a reference mode, obtains the section power difference equation of all section combinations and the reference mode, and calculates the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode, including:

[0031] For any reference method, the safety boundary equation constraints corresponding to all methods of the adjustment order are subtracted from the safety boundary constraint equations corresponding to the reference method to obtain a power difference equation group, and m-1 equations are selected from the power difference equations and solved to obtain a set of coupling coefficient solutions. The cross-section coupling coefficient solutions are obtained for each case; where m is the number of cross-sections; N is the number of cross-section limit combinations;

[0032] The obtained coupling coefficient solutions are evaluated and screened, and feasible solutions that meet the actual operation requirements are retained. The average of the screened coupling coefficient solutions is calculated to obtain the cross-section coupling coefficient corresponding to the benchmark method.

[0033] Preferably, the correction unit brings the average cross-section coupling coefficient into the safety boundary linear constraint condition, performs verification and correction of the coupling coefficient based on the safety margin, obtains the cross-section coupling coefficient that satisfies the safety boundary, and realizes multi-level cross-section safety boundary fitting, including:

[0034] Substituting the average cross-section coupling coefficient into the safety boundary linear constraint condition, obtaining the average value of N safety margin fitting values; wherein N is the number of cross-section limit combinations;

[0035] The coupling coefficients of each section are scaled based on the degree of deviation of the safety margin fitting average value relative to the original safety margin to obtain the section coupling coefficients that meet the safety boundary, thereby realizing multi-level section safety boundary fitting.

[0036] The present invention provides a method and system for fitting the safety boundary of a multi-level section of a power system, comprising: constructing a safety boundary linear constraint condition; substituting the section limit combination mode in the adjustment order into the safety boundary linear constraint condition, selecting any section combination as a reference mode in turn, obtaining the section power difference equation between all section combinations and the reference mode, and calculating the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode; calculating the average of the section coupling coefficients corresponding to all reference modes to obtain the average section coupling coefficient; bringing the average section coupling coefficient into the safety boundary linear constraint condition, checking and correcting the coupling coefficient based on the safety margin, obtaining the section coupling coefficient that meets the safety boundary, and realizing multi-level section safety boundary fitting. The present invention first constructs safety boundary equation constraint conditions according to the multi-level section coupling situation, and substitutes the actual operation mode adjustment single section combination mode into the safety boundary equation group to obtain the safety boundary equation group, providing a data basis for subsequent solution; the power difference equation group is solved by transforming the reference mode to obtain the average section coupling coefficient to approximate the actual coupling relationship of the fitting section; finally, the section coupling coefficient is corrected according to the safety margin, which can fit the safety boundary of the actual operation mode and effectively evaluate the safety of the existing operation mode; the present invention is conducive to the power system operation management personnel to formulate reasonable operation mode section limits according to the output and load distribution characteristics, to ensure the safe and stable operation of the power system while improving the energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0038] Figure 1 It is a flowchart of a method 100 for fitting a multi-level section safety boundary of a power system according to an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of a power system safety margin fitting process according to an embodiment of the present invention;

[0040] Figure 3 Schematic diagram of distribution of linear fitting values ​​of Px=ε and ΔPx=0 according to different reference modes of the embodiment of the present invention;

[0041] Figure 4 4 is a schematic diagram of the structure of a power system multi-section safety boundary fitting system 400 according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0043] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0044] The multi-level section safety boundary fitting method of the power system provided by the present invention forms a multi-dimensional coordinate system with the multi-level section limit power, and the multi-level section limit power of the existing boundary operation mode forms a hyperplane in the multi-dimensional coordinate system as the power system safety domain boundary. A new hyperplane is constructed by parameter fitting for the multi-level section limit power of the power system, which is as close to the hyperplane formed by the safety boundary as possible, and the safety boundary constraints are clarified to formulate a safe and efficient operation mode multi-level section limit combination.

[0045] Figure 1 FIG. 1 is a flow chart of a method 100 for fitting a multi-level section safety boundary of a power system according to an embodiment of the present invention. Figure 1 As shown, the multi-level section safety boundary fitting method of the power system provided by the embodiment of the present invention first constructs the safety boundary equation constraint conditions according to the multi-level section coupling situation, and substitutes the actual operation mode adjustment single section combination mode into the safety boundary equation group to provide a data basis for subsequent solution; solves the power difference equation group by transforming the reference mode to obtain the average section coupling coefficient to approximate the fitting section coupling relationship; finally, the section coupling coefficient is corrected according to the safety margin, which can fit the actual operation mode safety boundary and effectively evaluate the safety of the existing operation mode; the present invention is conducive to the power system operation and management personnel to formulate reasonable operation mode section limits according to the output and load distribution characteristics, and to ensure the safe and stable operation of the power system while improving energy utilization efficiency. The multi-level section safety boundary fitting method 100 provided by the embodiment of the present invention starts from step 101. In step 101, a safety boundary linear constraint condition is constructed.

[0046] Preferably, the step of constructing a safety boundary linear constraint condition comprises:

[0047] Each section is taken as a dimension, and multiple sections in the area constitute a multidimensional coordinate system. A set of multi-level section power limits corresponds to a mapping value that reflects the safety domain. The power of each section and the system safety and stability level are taken as independent variables and dependent variables respectively, and inequality safety constraints are constructed to obtain safety boundary constraints.

[0048] Preferably, the inequality safety constraint condition is: Where i = 1, 2, ..., m, m is the number of sections, P is the active power of the i-th section, k i is the coupling coefficient of the i-th section, ε is the safety margin;

[0049] The safety boundary constraints are: Among them, P i up is the power limit of the i-th section.

[0050] In the present invention, step 1 is to construct a linear constraint relationship of the safety boundary of each section. Among them, each section is taken as a dimension, multiple sections in the region constitute a multidimensional coordinate system, and a set of multi-level section limits corresponds to a mapping value that reflects the safety domain. The power of each section and the safety and stability level of the system are used as independent variables and dependent variables respectively, and an inequality safety constraint condition in the form of aX≤b is constructed. Further taking the equal sign, the safety boundary constraint aX=b is obtained.

[0051] Among them, the multidimensional coordinate system is composed of multiple closely coupled sections. In this coordinate system, there is a hyperplane area composed of the worst operation mode of the power system, which can be regarded as the safe operation domain of the power system. The actual operation mode needs to meet the safety constraints, that is, within the safety domain of the multidimensional coordinate system, any point in the domain can represent the operation mode corresponding to a set of section limit combinations.

[0052] Among them, the inequality safety constraint condition means that the section power limit must be within the safety boundary. For any operation mode, its safety constraint condition can be expressed as Where i = 1, 2, …, m is the active power of the m sections considered, k is the coupling coefficient of each section, and ε is the safety margin, which can represent the voltage stability level, inertia level or other safety level evaluation indicators.

[0053] Among them, the safety boundary constraint is the equal sign form of the above inequality safety constraint condition. In the multidimensional coordinate system, the limit combinations within the safety domain are all safe and reasonable, and the points on the safety domain hyperplane are critical safety methods. The existing adjustment orders formulate limit combinations based on expert experience, and all combinations are considered to be within the safety boundary. Therefore, the safety boundary constraint is P i upIt represents the power limit of section i, that is, the operating power of the section within the safety boundary.

[0054] In step 102, the section limit combination method in the adjustment order is substituted into the safety boundary linear constraint condition, and any section combination is selected as the reference method in turn, and the section power difference equation of all section combinations and the reference method is obtained, and the coupling coefficient is calculated based on the power difference equation to obtain the section coupling coefficient corresponding to each reference method.

[0055] Preferably, the step of sequentially selecting any one section combination as a reference mode, obtaining the section power difference equations of all section combinations and the reference mode, and calculating the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode comprises:

[0056] For any reference method, the safety boundary equation constraints corresponding to all methods of the adjustment order are subtracted from the safety boundary constraint equations corresponding to the reference method to obtain a power difference equation group, and m-1 equations are selected from the power difference equations and solved to obtain a set of coupling coefficient solutions. The cross-section coupling coefficient solutions are obtained for each case; where m is the number of cross-sections; N is the number of cross-section limit combinations;

[0057] The obtained coupling coefficient solutions are evaluated and screened, and feasible solutions that meet the actual operation requirements are retained. The average of the screened coupling coefficient solutions is calculated to obtain the cross-section coupling coefficient corresponding to the benchmark method.

[0058] Combination Figure 2 As shown, in the present invention, step 2 is to select a reference method and solve the coupling coefficient for the difference equation corresponding to the N section limit combinations in the adjustment order. Specifically, all section limit combinations in the adjustment order are substituted into the linear safety boundary equation constraints established above, and a set of section combinations is selected as the reference method. Solve the difference equation group between the equation group and the reference method to obtain a set of section coupling coefficient solutions K = [k1, k2, ..., k m ]. Select m-1 equations from N-1 equations to find non-zero solutions, take the average of the coupling coefficient solutions after evaluation and screening, and obtain the average cross-sectional coupling coefficient under the corresponding benchmark method.

[0059] The difference equation group is obtained by subtracting the safety boundary equation constraints corresponding to all the adjustment methods from the safety boundary constraint equations corresponding to the selected benchmark method. Assuming that the selected benchmark method is numbered (t), N section limit combinations are subtracted from the safety boundary equation (t) in turn to obtain N-1 equations, that is, the form ΔP [(N-1)×m] ·K (t) [m×1]=0, where N>>m. In practice, the above equation is simplified according to the actual characteristics of each section in the difference equation.

[0060] In order to obtain a non-zero solution, it is necessary to select m-1 equations from the system of equations to form a system of equations, solve the linear homogeneous system of equations, and obtain a set of coupling coefficients For all The cross-section coupling coefficient solutions are obtained for each case.

[0061] Among them, evaluating and screening the coupling coefficient solution means removing the solution that does not meet the actual operation requirements. According to the coupling relationship between the sections, the situation where the coupling coefficient of a section in the solution result is approximately 0 or 1 does not meet the actual operation requirements, and the solution needs to be removed from the result. The remaining feasible solutions after the group solution are averaged to obtain the cross-section coupling coefficient under the benchmark mode (t):

[0062] In step 103, the cross-sectional coupling coefficients corresponding to all the reference modes are averaged to obtain an average cross-sectional coupling coefficient.

[0063] Combination Figure 2 As shown, in the present invention, the coupling coefficients after traversing all the reference modes of the adjustment list are averaged. The N modes in the adjustment list are all used as reference modes, that is, the reference modes are changed and step 2 is repeated, and the N average coupling coefficients are averaged to obtain the cross-sectional coupling coefficient.

[0064] Among them, taking the average of the coupling coefficient means solving N safety boundary methods as the benchmark method and then taking the average. Since there are deviations in the cross-section coupling coefficients obtained by different benchmark methods, the results obtained by a single benchmark method are difficult to adapt to all safety boundary methods. Taking the average of the cross-section coupling coefficients of each benchmark method can better fit the actual safety boundary of the adjustment unit and the actual coupling relationship of each section. Take the average value to get the average cross-sectional coupling coefficient

[0065] In step 104, the average cross-section coupling coefficient is introduced into the safety boundary linear constraint condition, and the coupling coefficient is checked and corrected based on the safety margin to obtain the cross-section coupling coefficient that meets the safety boundary, thereby realizing multi-level cross-section safety boundary fitting.

[0066] Preferably, the average cross-section coupling coefficient is brought into the safety boundary linear constraint condition, the coupling coefficient is checked and corrected based on the safety margin, the cross-section coupling coefficient that satisfies the safety boundary is obtained, and multi-level cross-section safety boundary fitting is realized, including:

[0067] Substituting the average cross-section coupling coefficient into the safety boundary linear constraint condition, obtaining the average value of N safety margin fitting values; wherein N is the number of cross-section limit combinations;

[0068] The coupling coefficients of each section are scaled based on the degree of deviation of the safety margin fitting average value relative to the original safety margin to obtain the section coupling coefficients that meet the safety boundary, thereby realizing multi-level section safety boundary fitting.

[0069] In the present invention, the coupling coefficient is finally corrected based on the safety margin. That is, the cross-section coupling coefficient solved by the difference equation is substituted into the safety boundary equation constraint condition constructed in step 1, and the coupling coefficient of each cross section is scaled exponentially based on the safety margin calculated by the fitting result and the average offset of the original safety margin value.

[0070] The average offset of the safety margin refers to the average offset of the cross-section coupling coefficient after substituting it into the safety boundary constraint condition of the adjustment order. The average value of the N safety margin fitting values ​​obtained Scaling the cross-section coupling coefficient is to make the safety margin fitting value match the safety margin value in the constructed safety boundary constraint condition. Then expand both sides of the equation times, there are: have to The coupling coefficient of the section that meets the safety boundary is obtained, and the multi-level section safety boundary fitting is realized.

[0071] The method provided by the present invention is beneficial for power system operation and management personnel to formulate reasonable operation mode section limits according to output and load distribution characteristics, thereby ensuring the safe and stable operation of the power system and improving energy utilization efficiency.

[0072] The following specifically illustrates the embodiments of the present invention.

[0073] The embodiment of the present invention is the actual power system flow section operation data of a certain area, and the flow sections include: HXWS flow section, XJWS flow section, DY flow section, GY flow section, QY flow section, HY flow section and JQ DC seven related sections and DC.

[0074] The multi-level section safety boundary fitting of the power system is divided into the following steps:

[0075] Step 1: Construct the linear constraint relationship of the cross-section safety boundary.

[0076] Step 2: Select the benchmark method and solve the coupling coefficient for the difference equation corresponding to the N section limit combinations in the adjustment order.

[0077] Step three, take the average of the coupling coefficients after traversing all the benchmark modes of the adjustment order.

[0078] Step 4: Check and correct the coupling coefficient based on the safety margin.

[0079] The linear constraints of the section safety boundary in step 1 involve the seven section power limits mentioned above. A set of section power limits is: The safety margin value is evaluated based on the voltage stability per unit value. According to the limit combination in the existing adjustment order, the stability constraint equation is as follows:

[0080] aP a +bP b +cP c +dP d +eP e +fP f +gP g ≤1

[0081] The safety boundary constraint condition is further obtained as follows:

[0082] aP a +bP b +cP c +dP d +eP e +fP f +gP g =1

[0083] Among them, a, b, c, d, e, f, g correspond to the coefficients of HXWS, XJWS, DY, GY, QY, HY and JQ section limits respectively, P a ,P b ,P c ,P d ,P e ,P f ,P g They respectively represent the power limits corresponding to the sections.

[0084] The difference equation in step 2 can be obtained based on any reference equation, as

[0085] aΔP a +bΔP b +cΔP c +dΔP d +eΔP e +fΔP f +gΔP g =0

[0086] In actual calculation, the above equation can be simplified according to the actual characteristics of each section. For example, since the DY, GY, QY, and HY sections are on the same interconnected channel, their section power limits and power differences between different combinations are approximately the same. It can be considered that the effects of these four sections are similar and their coefficients are approximately equal. Therefore, the above equation is simplified to: aΔP a +bΔP b +f'ΔP f +gΔP g =0.

[0087] By selecting any three equations from them, we can get a set of equations of the form ΔPx = 0, and then find a set of non-zero coefficient solutions. All the difference equations are solved by permutation and combination, and after removing the interference terms, the feasible solutions are averaged to get a set of cross-section coupling coefficients to fit the safety boundary.

[0088] The traversal benchmark method of step three takes all section limit combinations in the existing adjustment order as the benchmark value, obtains the difference equation between other limit combinations and the benchmark method, repeats step two, and obtains the section limit coupling coefficient under different benchmark methods.

[0089] The coupling coefficient in step 3 is averaged, that is, the section limit coefficients obtained based on different benchmark methods are averaged. The fitting results obtained by different benchmark methods are as follows Figure 3 shown.

[0090] The correction coefficient in step 4 is based on the safety margin index (voltage stability value is 1), and the safety margin parameter fitting result calculated in step 3 is scaled up by multiples. Substitute the safety boundary section coefficient obtained in step 3 into the existing section limit combination of the adjustment order, and the scaling multiples of each parameter are:

[0091]

[0092] The final parameters and fitting results are shown in Table 1.

[0093] Table 1 Coupling parameters of each section

[0094]

[0095]

[0096] The fitted section coefficient can simply fit the coupling relationship between the sections and be used to characterize the safety boundary of the power system.

[0097] Figure 4 FIG. 4 is a schematic diagram of a multi-level cross-section safety boundary fitting system 400 for a power system according to an embodiment of the present invention. Figure 4As shown, a power system multi-level section safety boundary fitting system 400 provided in an embodiment of the present invention includes: a constraint condition construction unit 401, a section coupling coefficient determination unit 402, an average section coupling coefficient determination unit 403 and a correction unit 404.

[0098] Preferably, the constraint condition construction unit 401 is used to construct a safety boundary linear constraint condition.

[0099] Preferably, the constraint condition building unit 401 builds the safety boundary linear constraint condition, including:

[0100] Each section is taken as a dimension, and multiple sections in the area constitute a multidimensional coordinate system. A set of multi-level section power limits corresponds to a mapping value that reflects the safety domain. The power of each section and the system safety and stability level are taken as independent variables and dependent variables respectively, and inequality safety constraints are constructed to obtain safety boundary constraints.

[0101] Preferably, the inequality safety constraint condition is: Where i = 1, 2, ..., m, m is the number of sections, P is the active power of the i-th section, k i is the coupling coefficient of the i-th section, ε is the safety margin;

[0102] The safety boundary constraints are: Among them, P i up is the power limit of the i-th section.

[0103] Preferably, the section coupling coefficient determination unit 402 is used to substitute the section limit combination method in the adjustment order into the safety boundary linear constraint condition, select any section combination as the reference method in turn, obtain the section power difference equation between all section combinations and the reference method, and calculate the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference method.

[0104] Preferably, the section coupling coefficient determination unit 402 sequentially selects any section combination as a reference mode, obtains the section power difference equation of all section combinations and the reference mode, and calculates the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode, including:

[0105] For any reference method, the safety boundary equation constraints corresponding to all methods of the adjustment order are subtracted from the safety boundary constraint equations corresponding to the reference method to obtain a power difference equation group, and m-1 equations are selected from the power difference equations and solved to obtain a set of coupling coefficient solutions. The cross-section coupling coefficient solutions are obtained for each case; where m is the number of cross-sections; N is the number of cross-section limit combinations;

[0106] The obtained coupling coefficient solutions are evaluated and screened, and feasible solutions that meet the actual operation requirements are retained. The average of the screened coupling coefficient solutions is calculated to obtain the cross-section coupling coefficient corresponding to the benchmark method.

[0107] Preferably, the average cross-section coupling coefficient determining unit 403 is used to average the cross-section coupling coefficients corresponding to all reference modes to obtain the average cross-section coupling coefficient.

[0108] Preferably, the correction unit 404 is used to bring the average cross-section coupling coefficient into the safety boundary linear constraint condition, perform calibration and correction on the coupling coefficient based on the safety margin, obtain the cross-section coupling coefficient that meets the safety boundary, and realize multi-level cross-section safety boundary fitting.

[0109] Preferably, the correction unit brings the average cross-section coupling coefficient into the safety boundary linear constraint condition, performs verification and correction of the coupling coefficient based on the safety margin, obtains the cross-section coupling coefficient that satisfies the safety boundary, and realizes multi-level cross-section safety boundary fitting, including:

[0110] Substituting the average cross-section coupling coefficient into the safety boundary linear constraint condition, obtaining the average value of N safety margin fitting values; wherein N is the number of cross-section limit combinations;

[0111] The coupling coefficients of each section are scaled based on the degree of deviation of the safety margin fitting average value relative to the original safety margin to obtain the section coupling coefficients that meet the safety boundary, thereby realizing multi-level section safety boundary fitting.

[0112] The power system multi-section safety boundary fitting system 400 of the embodiment of the present invention corresponds to the power system multi-section safety boundary fitting method 100 of another embodiment of the present invention, and will not be described in detail here.

[0113] The present invention has been described with reference to a few embodiments. However, it is known to those skilled in the art that other embodiments than the one disclosed above are equally within the scope of the present invention.

[0114] Generally, all terms used in the present invention are interpreted according to their ordinary meaning in the technical field, unless otherwise explicitly defined therein. All references to "a / said / the [device, component, etc.]" are open to interpretation as at least one instance of the device, component, etc., unless otherwise explicitly stated. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated.

[0115] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0116] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0117] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0118] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for fitting the safety boundary of a multi-level section of a power system, characterized in that: The method comprises: Construct safety boundary linear constraints; Substitute the section limit combination method in the adjustment order into the safety boundary linear constraint condition, select any section combination as the reference method in turn, obtain the section power difference equation of all section combinations and the reference method, and calculate the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference method; The cross-sectional coupling coefficients corresponding to all the benchmark methods are averaged to obtain the average cross-sectional coupling coefficient; The average cross-section coupling coefficient is introduced into the safety boundary linear constraint condition, and the coupling coefficient is checked and corrected based on the safety margin to obtain the cross-section coupling coefficient that meets the safety boundary, thereby realizing multi-level cross-section safety boundary fitting.

2. The method according to claim 1, characterized in that The construction of the safety boundary linear constraint condition includes: Each section is taken as a dimension, and multiple sections in the area constitute a multidimensional coordinate system. A set of multi-level section power limits corresponds to a mapping value that reflects the safety domain. The power of each section and the system safety and stability level are taken as independent variables and dependent variables respectively, and inequality safety constraints are constructed to obtain safety boundary constraints.

3. The method according to claim 2, characterized in that The inequality safety constraint condition is: Where i = 1, 2, ..., m, m is the number of sections, P is the active power of the i-th section, k i is the coupling coefficient of the i-th section, ε is the safety margin; The safety boundary constraints are: Among them, P i up is the power limit of the i-th section.

4. The method according to claim 1, characterized in that: The method of sequentially selecting any section combination as a reference mode, obtaining the section power difference equation of all section combinations and the reference mode, and calculating the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode includes: For any reference method, the safety boundary equation constraints corresponding to all methods of the adjustment order are subtracted from the safety boundary constraint equations corresponding to the reference method to obtain a power difference equation group, and m-1 equations are selected from the power difference equations and solved to obtain a set of coupling coefficient solutions. The cross-section coupling coefficient solutions are obtained for each case; where m is the number of cross-sections; N is the number of cross-section limit combinations; The obtained coupling coefficient solutions are evaluated and screened, and feasible solutions that meet the actual operation requirements are retained. The average of the screened coupling coefficient solutions is calculated to obtain the cross-section coupling coefficient corresponding to the benchmark method.

5. The method according to claim 1, characterized in that The average cross-section coupling coefficient is brought into the safety boundary linear constraint condition, and the coupling coefficient is checked and corrected based on the safety margin to obtain the cross-section coupling coefficient that meets the safety boundary, thereby realizing multi-level cross-section safety boundary fitting, including: Substituting the average cross-section coupling coefficient into the safety boundary linear constraint condition, obtaining the average value of N safety margin fitting values; wherein N is the number of cross-section limit combinations; The coupling coefficients of each section are scaled based on the degree of deviation of the safety margin fitting average value relative to the original safety margin to obtain the section coupling coefficients that meet the safety boundary, thereby realizing multi-level section safety boundary fitting.

6. A multi-level section safety boundary fitting system for a power system, characterized in that: The system comprises: Constraint building unit, used to build safety boundary linear constraints; A section coupling coefficient determination unit is used to substitute the section limit combination mode in the adjustment order into the safety boundary linear constraint condition, select any section combination as the reference mode in turn, obtain the section power difference equation of all section combinations and the reference mode, and calculate the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode; The average cross-sectional coupling coefficient determination unit is used to average the cross-sectional coupling coefficients corresponding to all reference modes to obtain the average cross-sectional coupling coefficient; The correction unit is used to bring the average cross-section coupling coefficient into the safety boundary linear constraint condition, perform verification and correction of the coupling coefficient based on the safety margin, obtain the cross-section coupling coefficient that meets the safety boundary, and realize multi-level cross-section safety boundary fitting.

7. The system according to claim 6, characterized in that The constraint condition construction unit constructs a safety boundary linear constraint condition, including: Each section is taken as a dimension, and multiple sections in the area constitute a multidimensional coordinate system. A set of multi-level section power limits corresponds to a mapping value that reflects the safety domain. The power of each section and the system safety and stability level are taken as independent variables and dependent variables respectively, and inequality safety constraints are constructed to obtain safety boundary constraints.

8. The system according to claim 7, characterized in that The inequality safety constraint condition is: Where i = 1, 2, ..., m, m is the number of sections, P is the active power of the i-th section, k i is the coupling coefficient of the i-th section, ε is the safety margin; The safety boundary constraints are: Among them, P i up is the power limit of the i-th section.

9. The system according to claim 6, characterized in that The average section coupling coefficient determination unit sequentially selects any section combination as a reference mode, obtains the section power difference equation of all section combinations and the reference mode, and calculates the coupling coefficient based on the power difference equation to obtain the section coupling coefficient corresponding to each reference mode, including: For any reference method, the safety boundary equation constraints corresponding to all methods of the adjustment order are subtracted from the safety boundary constraint equations corresponding to the reference method to obtain a power difference equation group, and m-1 equations are selected from the power difference equations and solved to obtain a set of coupling coefficient solutions. The cross-section coupling coefficient solutions are obtained for each case; where m is the number of cross-sections; N is the number of cross-section limit combinations; The obtained coupling coefficient solutions are evaluated and screened, and feasible solutions that meet the actual operation requirements are retained. The average of the screened coupling coefficient solutions is calculated to obtain the cross-section coupling coefficient corresponding to the benchmark method.

10. The system according to claim 6, characterized in that The correction unit brings the average cross-section coupling coefficient into the safety boundary linear constraint condition, performs verification and correction of the coupling coefficient based on the safety margin, obtains the cross-section coupling coefficient that satisfies the safety boundary, and implements multi-level cross-section safety boundary fitting, including: Substituting the average cross-section coupling coefficient into the safety boundary linear constraint condition, obtaining the average value of N safety margin fitting values; wherein N is the number of cross-section limit combinations; The coupling coefficients of each section are scaled based on the degree of deviation of the safety margin fitting average value relative to the original safety margin to obtain the section coupling coefficients that meet the safety boundary, thereby realizing multi-level section safety boundary fitting.

Images