Minimum startup method for receiving-end power grid considering voltage stability and DC commutation failure

Abstract

The present application provides a method and system, electronic equipment, storage medium, and computer program product for minimum power-up of a receiving-end power grid, taking into account voltage stability and DC commutation failures, and relates to the field of power systems and their automation. This method integrates static voltage stability, transient voltage stability, and DC commutation failure assessments. By calculating the generator's static voltage support effect index, transient voltage support effect index, and DC commutation bus voltage interaction index, it forms a minimum power-up scheme for the receiving-end power grid, taking into account voltage stability and DC commutation failures. This scheme can effectively provide voltage support for multi-DC-fed receiving-end power grids, reduce the number of DC commutation failures, and mitigate the impact of AC / DC faults on the power grid.

Description

Technical Field

[0001] The present application relates to the field of power systems and automation thereof, and in particular to a minimum startup method and system for a receiving-end power grid taking into account voltage stability and DC commutation failure, an electronic device, a storage medium, and a computer program product. Background Art

[0002] In receiving grids with multiple DC feeds, the AC and DC systems interact in complex ways. As the proportion of DC power increases, the number of generators operating within the receiving grid decreases. During transient and dynamic processes following disturbances, the system suffers from insufficient reactive power, and busbar voltage stability cannot be maintained, easily leading to system voltage instability or voltage collapse. When power supply support is lacking near the DC converter station, AC faults can cause DC commutation failures. Simultaneous commutation failures in multiple DC circuits can severely impact the stable operation of the receiving grid, placing higher demands on the minimum generator operating mode within receiving grids with multiple DC feeds.

[0003] Therefore, a minimum startup method for the receiving-end power grid that takes into account voltage stability and DC commutation failure is needed to provide a quantitative reference for the startup method of the receiving-end power grid with multiple DC feeds. This is of great significance in the context of a high proportion of power electronic equipment access. Summary of the Invention

[0004] In view of the above problems, the present application is proposed to provide a method and system for minimum power-up of a receiving-end power grid, taking into account voltage stability and DC commutation failure, electronic equipment, storage medium, and computer program product, which overcome or at least partially resolve the above problems. This method can effectively provide voltage support for a multi-DC feed-in receiving-end power grid, reduce the number of DC commutation failures, and mitigate the impact of AC and DC faults on the power grid. The technical solution is as follows:

[0005] In a first aspect, a minimum power-on method for a receiving-end power grid taking into account voltage stability and DC commutation failure is provided, comprising:

[0006] Step S01, forming multi-DC feed-in receiving-end power grid data;

[0007] Step S02, forming an initial minimum startup mode;

[0008] Step S03: Calculate and sort the regional static voltage stability margins after multiple DC faults in the grid; take the DC corresponding to the minimum static voltage stability margin as the DC with the most serious fault; calculate and sort the generator static voltage support effect index under the DC blocking condition of the serious fault; determine whether the regional load active power margin meets the static voltage stability margin requirements under the current startup mode; if so, proceed to the next step S04; otherwise, activate the unit with the largest static voltage support effect index, form a new startup mode, and recalculate the generator static voltage support effect index and static voltage stability margin until the static voltage stability margin meets the requirements; and form a minimum startup plan that takes into account the static voltage stability margin.

[0009] Step S04: Calculate the transient voltage stability margins of the regional receiving-end power grid under different faults under the current startup mode and sort them; take the fault with the smallest transient voltage stability margin as the weak section fault; calculate the transient voltage support effect index of the generator under the weak section fault and sort them; determine whether the transient voltage stability margin is positive under the weak section fault; if so, proceed to the next step S05; otherwise, put the unit with the largest transient voltage support effect index into use, form a new startup mode, and recalculate the transient voltage support effect index and transient voltage stability margin of the generator until the transient voltage stability margin is positive; and form a minimum startup plan that takes the transient voltage stability margin into account.

[0010] Step S05: Calculate the commutation failure of the multi-infeed DC under different AC faults in the current startup mode; calculate the interaction index between the generator and the DC converter station and rank them; determine the commutation failure of the multi-infeed DC under different AC faults; if the single-circuit DC commutation failure is less than 2 times and the multi-circuit DC commutation failure is less than 2 times, then proceed to the next step S06; otherwise, the unit with the largest interaction index between the generator and the DC converter station is put into use, forming a new startup mode, and recalculating the interaction index between the generator and the DC converter station and the multi-infeed DC commutation failure until the single-circuit DC commutation failure is less than 2 times and the multi-circuit DC commutation failure is less than 2 times.

[0011] Step S06: forming a minimum startup plan that takes into account voltage stability and DC commutation failure.

[0012] Secondly, a minimum power-on system for a receiving-end power grid taking into account voltage stability and DC commutation failure is provided, including:

[0013] A first generating unit is used to generate multi-DC feed-in receiving-end power grid data;

[0014] The second generating unit is used to form an initial minimum startup mode;

[0015] The third generation unit is used to calculate and sort the regional static voltage stability margin after multiple DC faults in the grid; the DC corresponding to the minimum static voltage stability margin is used as the most serious fault DC; the generator static voltage support effect index under the serious fault DC blocking condition is calculated and sorted; it is determined whether the regional load active power margin meets the static voltage stability margin requirement under the current startup mode; if so, the fourth generation unit is entered; otherwise, the unit with the largest static voltage support effect index is put into use to form a new startup mode, and the generator static voltage support effect index and static voltage stability margin are calculated again until the static voltage stability margin meets the requirement; thus forming a minimum startup plan taking into account the static voltage stability margin;

[0016] The fourth generation unit is used to calculate the transient voltage stability margin of the regional receiving-end power grid under different faults under the current startup mode and sort them; the fault with the smallest transient voltage stability margin is regarded as the weak section fault; the transient voltage support effect index of the generator under the weak section fault is calculated and sorted; it is determined whether the transient voltage stability margin is positive under the weak section fault; if so, the fifth generation unit is entered; otherwise, the unit with the largest transient voltage support effect index is put into use to form a new startup mode, and the transient voltage support effect index and transient voltage stability margin of the generator are calculated again until the transient voltage stability margin is positive; thus, a minimum startup plan taking into account the transient voltage stability margin is formed;

[0017] The fifth generation unit is configured to calculate the commutation failure of the multi-infeed DC under different AC faults in the current startup mode; calculate and rank the interaction index between the generator and the DC converter station; and determine the commutation failure of the multi-infeed DC under different AC faults. If the number of single-circuit DC commutation failures is less than 2 and the number of simultaneous commutation failures of multiple DC circuits is less than 2, the sixth generation unit is entered; otherwise, the unit with the largest interaction index between the generator and the DC converter station is put into operation, forming a new startup mode, and the interaction index between the generator and the DC converter station and the multi-infeed DC commutation failure are calculated again until the number of single-circuit DC commutation failures is less than 2 and the number of simultaneous commutation failures of multiple DC circuits is less than 2.

[0018] The sixth generation unit is used to form a minimum startup plan taking into account voltage stability and DC commutation failure.

[0019] In a third aspect, an electronic device is provided, comprising a processor and a memory, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute any of the above-mentioned minimum start-up methods for the receiving-end power grid taking into account voltage stability and DC commutation failure.

[0020] In a fourth aspect, a storage medium is provided, which stores a computer program, wherein the computer program is configured to execute any of the above-mentioned minimum start-up methods for the receiving-end power grid taking into account voltage stability and DC commutation failure when running.

[0021] In a fifth aspect, a computer program product is provided, comprising a computer program, wherein the computer program is configured to execute any of the above-mentioned minimum start-up methods for a receiving-end power grid taking into account voltage stability and DC commutation failure when running.

[0022] By means of the above-mentioned technical solution, the embodiments of the present application provide a minimum start-up method and system for a receiving-end power grid taking into account voltage stability and DC commutation failure, an electronic device, a storage medium and a computer program product. The method integrates static voltage stability, transient voltage stability and DC commutation failure evaluation, and forms a minimum start-up scheme for a receiving-end power grid taking into account voltage stability and DC commutation failure by calculating the generator static voltage support effect index, transient voltage support effect index and DC commutation bus voltage interaction index. This scheme can effectively provide voltage support for a multi-DC feed-in receiving-end power grid, reduce the number of DC commutation failures, and reduce the impact of AC and DC faults on the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments of the present application.

[0024] Figure 1 A flowchart of a minimum power-on method for a receiving-end power grid taking into account voltage stability and DC commutation failure is shown in an embodiment of the present application;

[0025] Figure 2 A structural diagram of a minimum start-up system for a receiving-end power grid taking into account voltage stability and DC commutation failure provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] The following describes exemplary embodiments of the present application in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0027] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that such usage is interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the term "including" and its variations are to be interpreted as open-ended terms meaning "including but not limited to."

[0028] In order to solve the above technical problems, the embodiment of the present application provides a minimum power-on method for the receiving-end power grid taking into account voltage stability and DC commutation failure, such as Figure 1 As shown, the minimum startup method for the receiving-end power grid taking into account voltage stability and DC commutation failure may include the following steps S01 to S06:

[0029] Step S01: generating multi-DC feed-in receiving-end power grid data.

[0030] In this step, the structural parameters of the regional power grid, load level, generator set and capacity parameters of the fed-in DC are collected to form the multi-DC fed-in receiving-end power grid data.

[0031] Step S02: forming an initial minimum startup mode.

[0032] In this step, the initial minimum startup mode is generally determined based on the generator type. Initially, all gas-fired units responsible for peak load regulation in the regional power grid are shut down, one gas-fired unit responsible for heating is running, and one coal-fired unit per plant is running.

[0033] Step S03, calculate the regional static voltage stability margin after multiple DC faults in the grid and sort them; take the DC corresponding to the minimum static voltage stability margin as the most serious fault DC; calculate the generator static voltage support effect index under the serious fault DC locking condition and sort them; judge whether the regional load active power margin meets the static voltage stability margin requirement under the current startup mode; if so, proceed to the next step S04; otherwise, put the unit with the largest static voltage support effect index into use, form a new startup mode, and calculate the generator static voltage support effect index and static voltage stability margin again until the static voltage stability margin meets the requirement; form a minimum startup plan taking into account the static voltage stability margin.

[0034] Step S04, calculate the transient voltage stability margin of the regional receiving power grid under different faults under the current startup mode, and sort them; take the fault with the smallest transient voltage stability margin as the weak section fault; calculate the transient voltage support effect index of the generator under the weak section fault, and sort them; determine whether the transient voltage stability margin is positive under the weak section fault; if so, proceed to the next step S05; otherwise, put the unit with the largest transient voltage support effect index into use, form a new startup mode, calculate the generator transient voltage support effect index and transient voltage stability margin again, until the transient voltage stability margin is positive; form a minimum startup plan taking into account the transient voltage stability margin.

[0035] Step S05: Calculate the commutation failure of the multi-infeed DC under different AC faults under the current startup mode; calculate the interaction index between the generator and the DC converter station and sort them; determine the commutation failure of the multi-infeed DC under different AC faults; if the single-circuit DC commutation failure is less than 2 times and the multi-circuit DC commutation failure is less than 2 times, then proceed to the next step S06; otherwise, the unit with the largest interaction index between the generator and the DC converter station is put into use, forming a new startup mode, and recalculating the interaction index between the generator and the DC converter station and the multi-infeed DC commutation failure until the single-circuit DC commutation failure is less than 2 times and the multi-circuit DC commutation failure is less than 2 times.

[0036] Step S06: forming a minimum startup plan that takes into account voltage stability and DC commutation failure.

[0037] This embodiment can effectively provide voltage support for a multi-DC feed-in receiving-end power grid, reduce the number of DC commutation failures, and mitigate the impact of AC and DC faults on the power grid.

[0038] The present application provides a possible implementation method for calculating the generator static voltage support effect index. The static voltage support effect index consists of two parts: the first is the impact of generator switching on and off on the short-circuit capacity of the DC converter station, and the second is the degree of coupling between power transfer and AC bus voltage after DC blocking. These two parts together represent the generator static voltage support effect. Therefore, in step S03, the static voltage support effect index of the i-th generator is calculated as follows:

[0039]

[0040] Among them, C i is the static voltage support effect index of the i-th generator, S d is the initial value of the short-circuit capacity of the DC converter station busbar, S i P is the short-circuit capacity of the DC converter station busbar after the i-th generator is withdrawn, i is the rated power capacity of the i-th generator, Re(Z i) is the real part of the equivalent impedance from the DC converter station bus to the i-th generator, ΔU i is the variation amplitude of the bus voltage at the booster station of the i-th generator after DC blocking.

[0041] The embodiment of the present application provides a possible implementation method. In step S03, the active power margin of the regional load under the static voltage stability in the current startup mode is calculated as follows:

[0042]

[0043] Among them, K vp is the regional load active power margin under static voltage stability, P max is the active power value at the critical operating point, and P is the initial active power.

[0044] According to the "GB / T 40581-2021 Power System Security and Stability Calculation Specification", the static voltage stability margin includes: the active power margin of the regional load under normal mode is not less than 8%, and the active power margin of the regional load under N-1 fault mode is not less than 5%.

[0045] Starting from the basic operation mode of the power grid, the load power is increased in steps and the generator power is appropriately distributed. The power flow calculation is performed until the regional power receiving power reaches the critical transmission limit. The active power value at the critical operating point is obtained. Combined with the initial active power, the regional load active power margin under normal operation is calculated. The regional load active power margin is calculated after multiple DC faults in the grid. The DC corresponding to the minimum active power margin is regarded as the DC with the most serious fault.

[0046] Determine the active power margin K of regional load in the initial startup mode vp , whether the static voltage stability margin requirement of "not less than 8% under normal mode and not less than 5% under N-1 fault mode" is met; if so, enter step S04; otherwise, put the unit with the largest static voltage support effect index into use, form a new startup mode, and calculate the generator static voltage support effect index and static voltage stability margin again until the static voltage stability margin meets the requirement; form a minimum startup plan taking into account the static voltage stability margin.

[0047] The embodiment of the present application provides a possible implementation method, which uses time domain simulation to calculate the transient voltage stability margin of the regional receiving end power grid under different faults in the current startup mode and sort them. When the transient voltage stability margin is negative, the transient voltage is unstable. The smaller the algebraic value of the transient voltage stability margin, the worse the stability. Then, in step S04, the transient voltage stability margin is calculated as follows:

[0048]

[0049] Among them, η i,j is the transient voltage stability margin, U N is the rated voltage, U i,j (t) is the voltage of load bus j under fault i, t is the fault start time, Δt is U i,j (t) is lower than U N duration.

[0050] In the embodiment of the present application, a possible implementation method is provided, which regards the fault with the smallest transient voltage stability margin as a weak section fault; and calculates the transient voltage support effect index of the generator under the weak section fault. The generator excitation control system changes the terminal voltage by regulating reactive power. When a fault occurs in the power grid, the terminal voltage drops to varying degrees according to the size of the disturbance. The excitation control system quickly increases the excitation voltage according to the voltage difference, increases the capacitive reactive output of the generator, and thus suppresses the voltage drop. There are differences in the excitation capabilities of different generators, and different generators have different responses to the dynamic reactive power of the AC bus at the weak fault location. The reactive support effect of the generator can be characterized by the per-unit value and time integral of the dynamic reactive power increment of the generator within a period of time after the short-circuit fault. The larger the index, the more obvious the voltage stability support effect of the generator. Then, in step S04, the transient voltage support effect index of the i-th generator is calculated as follows:

[0051]

[0052] Among them, Q i is the transient voltage support effect index of the i-th generator, Q i (t+Δt) is the reactive power output of the i-th generator within Δt time, Q i (t) is the initial reactive power output of the i-th generator, S i is the rated capacity of the i-th generator.

[0053] The embodiments of the present application provide a possible implementation method. When a short circuit fault occurs in the AC system, if there are few DC units started in the vicinity of the DC landing point, the voltage and reactive power support capacity will be insufficient, which will make it difficult for the bus voltage of the converter station to recover in a short period of time. When the voltage is continuously lower than the critical voltage, it will cause multiple consecutive DC commutation failures, and a large amount of surplus power will impact the AC power grid. In severe cases, it will cause the receiving end power grid to become unstable. Traditional electromechanical transient simulation cannot accurately characterize the DC commutation process and the characteristics of the DC control system. The DC system uses electromagnetic transient modeling, and the AC power grid uses electromechanical transient modeling. The use of electromagnetic-electromechanical hybrid simulation can finely evaluate the DC commutation failure situation.

[0054] Using electromagnetic-electromechanical hybrid simulation methods, calculate the commutation failure of multi-fed DC under different AC faults in the current startup mode. Calculate the interaction index between the generator and the DC converter station. Under the condition of multiple DC feeds, there is not only the interaction between the generator AC bus and the DC converter bus, but also the interaction between multiple DC lines. The multi-DC interaction factor is used to measure the impact between the DC converter bus, and the AC-DC interaction factor is used to measure the effect between the AC bus and the DC converter bus. Then, in step S05, the interaction index between the i-th generator and multiple DC converter stations is calculated as follows:

[0055]

[0056] Among them, E i is the interaction index between the i-th generator and multiple DC converter stations, ΔUd j,k is the voltage variation amplitude of DC j commutation bus under the influence of reactive power impact of DC k commutation failure, ΔU k is the voltage variation amplitude of DC k commutation bus, ΔUac j,i ΔU is the voltage variation of DC commutation busbar j after the i-th generator is switched on and off. i is the bus voltage variation amplitude of the i-th generator booster station caused by the DC j commutation failure.

[0057] It should be noted that the order of execution of the steps in the above embodiments does not necessarily imply a specific order of execution. The order of execution of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In practical applications, all possible implementation methods described above can be combined in any manner to form possible embodiments of the present application, and will not be described in detail here.

[0058] Based on the minimum start-up method for the receiving-end power grid taking into account voltage stability and DC commutation failure provided in the above embodiments, based on the same inventive concept, an embodiment of the present application also provides a minimum start-up system for the receiving-end power grid taking into account voltage stability and DC commutation failure.

[0059] Figure 2 This is a structural diagram of the minimum start-up system of the receiving-end power grid taking into account voltage stability and DC commutation failure provided by the embodiment of the present application. Figure 2 As shown, the minimum startup system of the receiving-end power grid taking into account voltage stability and DC commutation failure can specifically include a first generation unit 210, a second generation unit 220, a third generation unit 230, a fourth generation unit 240, a fifth generation unit 250, and a sixth generation unit 260.

[0060] The first generating unit 210 is configured to generate multi-DC feed-in receiving-end power grid data;

[0061] The second generating unit 220 is used to form an initial minimum startup mode;

[0062] The third generation unit 230 is used to calculate and sort the regional static voltage stability margins after multiple DC faults in the grid; the DC corresponding to the minimum static voltage stability margin is used as the most serious fault DC; the generator static voltage support effect index under the serious fault DC blocking condition is calculated and sorted; determine whether the regional load active power margin meets the static voltage stability margin requirement under the current startup mode; if so, enter the fourth generation unit; otherwise, the unit with the largest static voltage support effect index is put into use, forming a new startup mode, and recalculating the generator static voltage support effect index and static voltage stability margin until the static voltage stability margin meets the requirement; thus forming a minimum startup plan taking into account the static voltage stability margin;

[0063] The fourth generation unit 240 is used to calculate the transient voltage stability margin of the regional receiving-end power grid under different faults under the current startup mode and sort them; the fault with the smallest transient voltage stability margin is regarded as the weak section fault; the transient voltage support effect index of the generator under the weak section fault is calculated and sorted; and it is determined whether the transient voltage stability margin is positive under the weak section fault; if so, the fifth generation unit is entered; otherwise, the unit with the largest transient voltage support effect index is put into use, a new startup mode is formed, and the transient voltage support effect index and transient voltage stability margin of the generator are calculated again until the transient voltage stability margin is positive, thereby forming a minimum startup plan that takes the transient voltage stability margin into account.

[0064] The fifth generation unit 250 is configured to calculate the commutation failure of the multi-infeed DC under different AC faults in the current startup mode; calculate and rank the interaction index between the generator and the DC converter station; and determine the commutation failure of the multi-infeed DC under different AC faults. If the number of single-circuit DC commutation failures is less than 2 and the number of simultaneous commutation failures of multiple DC circuits is less than 2, the process proceeds to the sixth generation unit. Otherwise, the unit with the largest interaction index between the generator and the DC converter station is put into operation, forming a new startup mode, and recalculating the interaction index between the generator and the DC converter station and the commutation failure of the multi-infeed DC until the number of single-circuit DC commutation failures is less than 2 and the number of simultaneous commutation failures of multiple DC circuits is less than 2.

[0065] The sixth generating unit 260 is configured to generate a minimum startup plan that takes voltage stability and DC commutation failure into consideration.

[0066] An embodiment of the present application provides a possible implementation method, in which the third generating unit 230 is further configured to:

[0067] Under the current startup mode, the regional load active power margin under static voltage stability is calculated as follows:

[0068]

[0069] Among them, K vp is the regional load active power margin under static voltage stability, P max is the active power value at the critical operating point, and P is the initial active power.

[0070] An embodiment of the present application provides a possible implementation method, in which the third generating unit 230 is further configured to:

[0071] The static voltage support effect index of the i-th generator is calculated as follows:

[0072]

[0073] Among them, C i is the static voltage support effect index of the i-th generator, S d is the initial value of the short-circuit capacity of the DC converter station busbar, S i P is the short-circuit capacity of the DC converter station busbar after the i-th generator is withdrawn, i is the rated power capacity of the i-th generator, Re(Z i ) is the real part of the equivalent impedance from the DC converter station bus to the i-th generator, ΔU i is the variation amplitude of the bus voltage at the booster station of the i-th generator after DC blocking.

[0074] An embodiment of the present application provides a possible implementation manner, in which the fourth generating unit 240 is further configured to:

[0075] The transient voltage stability margin is calculated as follows:

[0076]

[0077] Among them, η i,j is the transient voltage stability margin, U N is the rated voltage, U i,j (t) is the voltage of load bus j under fault i, t is the fault start time, Δt is U i,j (t) is lower than U N duration.

[0078] An embodiment of the present application provides a possible implementation manner, in which the fourth generating unit 240 is further configured to:

[0079] The transient voltage support effect index of the i-th generator is calculated as follows:

[0080]

[0081] Among them, Q iis the transient voltage support effect index of the i-th generator, Q i (t+Δt) is the reactive power output of the i-th generator within Δt time, Q i (t) is the initial reactive power output of the i-th generator, S i is the rated capacity of the i-th generator.

[0082] In an embodiment of the present application, a possible implementation is provided, in which the fifth generating unit 250 is further configured to:

[0083] The interaction index between the i-th generator and multiple DC converter stations is calculated as follows:

[0084]

[0085] Among them, E i is the interaction index between the i-th generator and multiple DC converter stations, ΔUd j,k is the voltage variation amplitude of DC j commutation bus under the influence of reactive power impact of DC k commutation failure, ΔU k is the voltage variation amplitude of DC k commutation bus, ΔUac j,i ΔU is the voltage variation of DC commutation busbar j after the i-th generator is switched on and off. i is the bus voltage variation amplitude of the i-th generator booster station caused by the DC j commutation failure.

[0086] Based on the same inventive concept, an embodiment of the present application also provides an electronic device, including a processor and a memory, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the minimum start-up method of the receiving-end power grid taking into account voltage stability and DC commutation failure of any of the above embodiments.

[0087] Based on the same inventive concept, an embodiment of the present application also provides a storage medium, which stores a computer program, wherein the computer program is configured to execute any one of the above-mentioned embodiments of the minimum start-up method for the receiving-end power grid taking into account voltage stability and DC commutation failure when running.

[0088] Based on the same inventive concept, an embodiment of the present application also provides a computer program product, including a computer program, which is configured to execute the minimum start-up method of the receiving-end power grid taking into account voltage stability and DC commutation failure of any of the above embodiments when running.

[0089] Those skilled in the art will clearly understand that the specific working processes of the systems, devices, and modules described above can refer to the corresponding processes in the aforementioned method embodiments, and for the sake of brevity, they will not be further described here.

[0090] Those skilled in the art will appreciate that the technical solution of the present application, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes a number of program instructions for causing an electronic device (e.g., a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application when the program instructions are executed. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0091] Alternatively, all or part of the steps of implementing the aforementioned method embodiments may be accomplished by hardware related to program instructions (such as electronic devices such as personal computers, servers, or network devices), and the program instructions may be stored in a computer-readable storage medium. When the program instructions are executed by a processor of an electronic device, the electronic device executes all or part of the steps of the methods described in the various embodiments of the present application.

[0092] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that, within the spirit and principles of the present application, they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate from the protection scope of the present application.

Claims

1. A minimum power-on method for a receiving-end power grid taking into account voltage stability and DC commutation failure, characterized in that: include: Step S01, forming multi-DC feed-in receiving-end power grid data; Step S02, forming an initial minimum startup mode; Step S03: Calculate and sort the regional static voltage stability margins after multiple DC faults in the grid; take the DC corresponding to the minimum static voltage stability margin as the DC with the most serious fault; calculate and sort the generator static voltage support effect index under the DC blocking condition of the serious fault; determine whether the regional load active power margin meets the static voltage stability margin requirements under the current startup mode; if so, proceed to the next step S04; otherwise, activate the unit with the largest static voltage support effect index, form a new startup mode, and recalculate the generator static voltage support effect index and static voltage stability margin until the static voltage stability margin meets the requirements; and form a minimum startup plan that takes into account the static voltage stability margin. Step S04, calculating the transient voltage stability margin of the regional receiving-end power grid under different fault conditions under the current startup mode, and ranking them; The fault with the smallest transient voltage stability margin is regarded as a weak section fault; the transient voltage support effect index of the generator under the weak section fault is calculated and ranked; it is determined whether the transient voltage stability margin under the weak section fault is positive; if so, the process proceeds to the next step S05; otherwise, the unit with the largest transient voltage support effect index is put into operation to form a new startup method, and the transient voltage support effect index and transient voltage stability margin of the generator are calculated again until the transient voltage stability margin is positive; thus, a minimum startup plan taking into account the transient voltage stability margin is formed; Step S05: Calculate the commutation failure of the multi-infeed DC under different AC faults in the current startup mode; calculate the interaction index between the generator and the DC converter station and rank them; determine the commutation failure of the multi-infeed DC under different AC faults; if the single-circuit DC commutation failure is less than 2 times and the multi-circuit DC commutation failure is less than 2 times, then proceed to the next step S06; otherwise, the unit with the largest interaction index between the generator and the DC converter station is put into use, forming a new startup mode, and recalculating the interaction index between the generator and the DC converter station and the multi-infeed DC commutation failure until the single-circuit DC commutation failure is less than 2 times and the multi-circuit DC commutation failure is less than 2 times. Step S06, forming a minimum startup plan taking into account voltage stability and DC commutation failure; Among them, in step S03, The static voltage support effect index of a generator is calculated as follows: in, For the The static voltage support effect index of the generator, is the initial value of the short-circuit capacity of the DC converter station busbar, To exit The short-circuit capacity of the DC converter busbar after the generator, For the Rated power capacity of the generator, For DC converter station bus to the The real part of the equivalent impedance of a generator, After DC blocking The variation amplitude of bus voltage of the generator booster station; In step S04, The transient voltage support effect index of a generator is calculated as follows: in, For the Transient voltage support effect index of each generator, For the generators Reactive power output within a certain time period, For the The initial reactive power output of the generator, For the Rated capacity of the generator; In step S05, The interaction index between a generator and multiple DC converter stations is calculated as follows: in, For the The interaction indicators between the generators and multiple DC converter stations, For DC DC current under the influence of commutation failure reactive power shock The commutation bus voltage variation amplitude, For DC The commutation bus voltage variation amplitude, To withdraw After the generator, DC The commutation bus voltage variation amplitude, For DC Phase commutation failure caused by The bus voltage variation amplitude of the generator booster station.

2. The method according to claim 1, characterized in that In step S03, the active power margin of the regional load under the static voltage stability in the current startup mode is calculated as follows: in, is the regional load active power margin under static voltage stability, is the active power value at the critical operating point, is the initial active power.

3. The method according to claim 1, characterized in that In step S04, the transient voltage stability margin is calculated as follows: in, is the transient voltage stability margin, is the rated voltage, For failure Lower load bus The voltage, is the fault start time, for Lower than duration.

4. A minimum power-on system for a receiving-end power grid taking into account voltage stability and DC commutation failure, characterized in that: include: A first generating unit is used to generate multi-DC feed-in receiving-end power grid data; The second generating unit is used to form an initial minimum startup mode; The third generation unit is used to calculate and sort the regional static voltage stability margins after multiple DC faults in the grid; The DC corresponding to the minimum static voltage stability margin is used as the most serious fault DC; the generator static voltage support effect index under the severe fault DC blocking condition is calculated and ranked; it is determined whether the regional load active power margin meets the static voltage stability margin requirement under the current startup mode; if so, the fourth generation unit is entered; otherwise, the unit with the largest static voltage support effect index is put into use, a new startup mode is formed, and the generator static voltage support effect index and static voltage stability margin are calculated again until the static voltage stability margin meets the requirement; thus, a minimum startup plan taking into account the static voltage stability margin is formed; The fourth generation unit is used to calculate the transient voltage stability margin of the regional receiving-end power grid under the current startup mode and different faults, and sort them; The fault with the smallest transient voltage stability margin is considered a weak section fault; the transient voltage support effect index of the generator under the weak section fault is calculated and ranked; whether the transient voltage stability margin is positive under the weak section fault is determined; if so, the fifth generation unit is entered; otherwise, the unit with the largest transient voltage support effect index is put into operation to form a new startup method, and the transient voltage support effect index and transient voltage stability margin of the generator are calculated again until the transient voltage stability margin is positive; thus, a minimum startup plan that takes the transient voltage stability margin into account is formed; The fifth generation unit is configured to calculate the commutation failure of the multi-infeed DC under different AC faults in the current startup mode; calculate and rank the interaction index between the generator and the DC converter station; and determine the commutation failure of the multi-infeed DC under different AC faults. If the number of single-circuit DC commutation failures is less than 2 and the number of simultaneous commutation failures of multiple DC circuits is less than 2, the sixth generation unit is entered; otherwise, the unit with the largest interaction index between the generator and the DC converter station is put into operation, forming a new startup mode, and the interaction index between the generator and the DC converter station and the multi-infeed DC commutation failure are calculated again until the number of single-circuit DC commutation failures is less than 2 and the number of simultaneous commutation failures of multiple DC circuits is less than 2. a sixth generation unit, configured to generate a minimum startup plan taking into account voltage stability and DC commutation failure; Among them, The static voltage support effect index of a generator is calculated as follows: in, For the The static voltage support effect index of the generator, is the initial value of the short-circuit capacity of the DC converter station busbar, To exit The short-circuit capacity of the DC converter busbar after the generator, For the Rated power capacity of the generator, For DC converter station bus to the The real part of the equivalent impedance of a generator, After DC blocking The variation amplitude of bus voltage of the generator booster station; No. The transient voltage support effect index of a generator is calculated as follows: in, For the Transient voltage support effect index of each generator, For the generators Reactive power output within a certain time period, For the The initial reactive power output of the generator, For the Rated capacity of the generator; No. The interaction index between a generator and multiple DC converter stations is calculated as follows: in, For the The interaction indicators between the generators and multiple DC converter stations, For DC DC current under the influence of commutation failure reactive power shock The commutation bus voltage variation amplitude, For DC The commutation bus voltage variation amplitude, To withdraw After the generator, DC The commutation bus voltage variation amplitude, For DC Phase commutation failure caused by The bus voltage variation amplitude of the generator booster station.

5. An electronic device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the minimum start-up method for the receiving-end power grid taking into account voltage stability and DC commutation failure according to any one of claims 1 to 3.

6. A storage medium, characterized in that The storage medium stores a computer program, wherein the computer program is configured to execute the minimum start-up method for the receiving-end power grid taking into account voltage stability and DC commutation failure according to any one of claims 1 to 3 when running.

7. A computer program product comprising a computer program, characterized in that The computer program is configured to execute the receiving-end power grid minimum startup method taking into account voltage stability and DC commutation failure according to any one of claims 1 to 3 when running.

Images