Receiving end power grid minimum starting method considering voltage stability and direct current commutation failure

Abstract

The invention provides a receiving end power grid minimum starting method and system considering voltage stability and direct current commutation failure, electronic equipment, a storage medium and a computer program product, and relates to the field of power systems and automation thereof. According to the method, static voltage stability, transient voltage stability and direct-current commutation failure evaluation are fused, and a receiving-end power grid minimum starting scheme considering voltage stability and direct-current commutation failure is formed by calculating a static voltage supporting effect index, a transient voltage supporting effect index and a direct-current commutation bus voltage interaction effect index of a generator. Voltage support can be effectively provided for a multi-direct-current feed-in receiving end power grid, the number of direct-current commutation failures is reduced, and the impact degree of alternating-current and direct-current faults on the power grid is reduced.

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 the receiving power grid with multiple DC feeds, the interaction between AC and DC systems is complex. As the proportion of DC power receiving continues to increase, the number of startups in the receiving power grid gradually decreases. In the transient and dynamic processes after disturbances, the system has insufficient reactive power and the bus voltage cannot remain stable, which can easily cause system voltage instability or voltage collapse. When there is a lack of power supply startup support near the DC converter station, AC faults cause DC commutation failures. Multiple DC commutation failures at the same time will seriously affect the stable operation of the receiving power grid, thus putting forward higher requirements for the minimum startup mode in the receiving power grid with multiple DC feeds.

[0003] Therefore, a minimum startup method for the receiving-end power grid taking into account voltage stability and DC commutation failure is needed to provide a quantitative reference for the startup method of multiple DC-fed receiving-end power grids, which 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 startup of 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 that overcome the above problems or at least partially solve the above problems, which 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. The technical solution is as follows:

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

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

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

[0008] 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 DC blocking condition of serious fault, and sort them; judge whether the regional load active power margin meets the static voltage stability margin requirement under the current startup mode; if yes, 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, calculate the generator static voltage support effect index and static voltage stability margin again, until the static voltage stability margin meets the requirements; form a minimum startup plan taking into account the static voltage stability margin;

[0009] Step S04, calculate the transient voltage stability margin 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, calculate the transient voltage support effect index of the generator and the 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;

[0010] Step S05, calculating the commutation failure of multi-input DC under different AC faults in the current startup mode; calculating the interaction index between the generator and the DC converter station and sorting them; judging the commutation failure of multi-input DC under different AC faults; if the single-circuit DC commutation failure is less than 2 times and the multiple-circuit DC commutation failure is less than 2 times at the same time, then proceeding 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 calculating the interaction index between the generator and the DC converter station and the multi-input DC commutation failure again, until the single-circuit DC commutation failure is less than 2 times and the multiple-circuit DC commutation failure is less than 2 times at the same time;

[0011] Step S06, forming a minimum startup plan taking into account voltage stability and DC commutation failure.

[0012] In a second aspect, a minimum start-up system for a receiving-end power grid taking into account voltage stability and DC commutation failure is provided, comprising:

[0013] A first generating unit, used for forming multi-DC feed-in receiving-end power grid data;

[0014] A second generating unit, used for forming 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; take the DC corresponding to the minimum static voltage stability margin as the most serious fault DC; calculate and sort the generator static voltage support effect index under the DC locking condition of serious fault; judge 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, 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;

[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; 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; judge whether the transient voltage stability margin is positive under the weak section fault; if so, enter the fifth generation unit; otherwise, put the unit with the largest transient voltage support effect index into use, form a new startup mode, calculate the transient voltage support effect index and transient voltage stability margin of the generator again, until the transient voltage stability margin is positive; form a minimum startup plan taking into account the transient voltage stability margin;

[0017] The fifth generation unit is used to calculate the commutation failure of multi-input DC under different AC faults in the current startup mode; calculate the interaction index between the generator and the DC converter station and sort them; determine the commutation failure of multi-input DC under different AC faults; if the single-loop DC commutation failure is less than 2 times and the simultaneous commutation failure of multiple DC is less than 2 times, enter the sixth generation unit; otherwise, put the unit with the largest interaction index between the generator and the DC converter station into use, form a new startup mode, and calculate the interaction index between the generator and the DC converter station and the multi-input DC commutation failure again, until the single-loop DC commutation failure is less than 2 times and the simultaneous commutation failure of multiple DC is less than 2 times;

[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, wherein the storage medium stores a computer program, wherein the computer program is configured to execute any of the above-mentioned minimum startup 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 technical scheme, the embodiments of the present application provide a method and system for the minimum startup of 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 startup scheme for a receiving-end power grid taking into account voltage stability and DC commutation failure by calculating the static voltage support effect index, transient voltage support effect index and DC commutation bus voltage interaction index of the generator. This can effectively provide voltage support for a multi-DC-fed 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 drawings required for use in describing the embodiments of the present application are briefly introduced below.

[0024] Figure 1 A flow chart of a minimum startup method 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;

[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 exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the 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. On the contrary, these embodiments are provided in order 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", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such use is interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the term "including" and its variants 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 startup method of the receiving-end power grid taking into account voltage stability and DC commutation failure, such as Figure 1 As shown, the minimum startup method of 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, forming multiple 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 data of the multi-DC fed-in receiving-end power grid.

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

[0032] In this step, the initial minimum startup mode is generally determined based on the type of generator set. In the initial state, all gas-fired units responsible for peak load regulation in the regional power grid are stopped, one gas-fired unit responsible for heating is started, and one coal-fired unit is started in each coal-fired power plant.

[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 severe fault DC locking condition, and sort them; determine 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 the 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 transient voltage support effect index of the generator and the 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 current startup mode, the commutation failure of the multi-input DC under different AC faults; calculate the interaction index between the generator and the DC converter station and sort them; judge the commutation failure of the multi-input DC under different AC faults; if the single-loop DC commutation failure is less than 2 times and the multiple DC commutation failures are less than 2 times at the same time, enter the next step S06; otherwise, put the unit with the largest interaction index between the generator and the DC converter station into use, form a new startup mode, and calculate the interaction index between the generator and the DC converter station and the multi-input DC commutation failure again, until the single-loop DC commutation failure is less than 2 times and the multiple DC commutation failures are less than 2 times at the same time.

[0036] Step S06, forming a minimum startup plan taking 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 reduce the impact of AC and DC faults on the power grid.

[0038] The embodiment of the present application provides a possible implementation method to calculate the generator static voltage support effect index, which consists of two parts: one is the influence of the generator switching on and off on the short-circuit capacity of the DC converter station, and the other is the coupling degree between the power transfer and the AC bus voltage after the DC blocking. The two parts jointly characterize the generator static voltage support effect. Then, 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 is the short-circuit capacity of the DC converter station busbar after the i-th generator is removed, P 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 change amplitude of bus voltage of the i-th generator booster station after DC blocking.

[0041] The embodiment of the present application provides a possible implementation method. In step S03, in the current startup mode, the regional load active power margin under static voltage stability 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 Safety and Stability Calculation Specifications", the static voltage stability margin includes: the active power margin of the regional load under normal conditions 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, increase the load power at a certain step size, and appropriately allocate the generator power to perform power flow calculations until the regional power reaches the critical transmission limit. The active power value of the critical operation point is obtained. Combined with the initial active power, the active power margin of the regional load under normal conditions is calculated. The active power margin of the regional load after multiple DC faults in the grid is calculated, and the DC corresponding to the minimum active power margin is taken 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 it meets the static voltage stability margin requirement of "not less than 8% under normal mode and not less than 5% under N-1 fault mode"; 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 the 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] In the embodiment of the present application, a possible implementation method is provided. By means of time domain simulation, the transient voltage stability margin of the regional receiving-end power grid under different faults in the current startup mode is calculated and sorted. 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, in which the fault with the smallest transient voltage stability margin is regarded as a weak section fault; and the transient voltage support effect index of the generator under the weak section fault is calculated. 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 rapidly 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 dynamic reactive responses to 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 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 the time Δt, 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 embodiment of the present application provides a possible implementation method. When a short circuit occurs in the AC system, if there are few DC units powered on in the vicinity of the DC landing point and the voltage reactive support capacity is insufficient, it will make it difficult for the converter station bus voltage to recover in a short period of time. When the voltage continues to be 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 DC control system characteristics. The DC system uses electromagnetic transient modeling, and the AC power grid uses electromechanical transient modeling. Electromagnetic-electromechanical hybrid simulation can be used to finely evaluate DC commutation failures.

[0054] Electromagnetic-electromechanical hybrid simulation is used to calculate the commutation failure of multi-fed DC under different AC faults in the current startup mode. The interaction index between the generator and the DC converter station is calculated. Under the condition of multiple DC feed-in, there is not only the interaction between the generator AC bus and the DC converter bus, but also the interaction between multiple DCs. The multi-DC interaction factor is used to measure the influence 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 the DC k commutation bus, ΔUac j,i ΔU is the voltage change amplitude of DC j commutation bus 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 size of the sequence number of each step in the above embodiment does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. In practical applications, all the above possible implementation methods can be combined in any way to form possible embodiments of the present application, which will not be described one by one here.

[0058] Based on the minimum startup method of 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 startup system of the receiving-end power grid taking into account voltage stability and DC commutation failure.

[0059] Figure 2 1 is a structural diagram of a minimum start-up system of a receiving-end power grid taking into account voltage stability and DC commutation failure provided by an 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 may 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] A first generating unit 210, 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 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 DC blocking condition of serious fault, 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, enter the fourth generation unit; 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;

[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; 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, enter the fifth generation unit; otherwise, put the unit with the largest transient voltage support effect index into use, form a new startup mode, calculate the transient voltage support effect index and transient voltage stability margin of the generator again, until the transient voltage stability margin is positive; form a minimum startup plan taking into account the transient voltage stability margin;

[0064] The fifth generation unit 250 is used to 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 sort them; determine the commutation failure of the multi-infeed DC under different AC faults; if the single-loop DC commutation failure is less than 2 times and the multiple DC commutation failures are less than 2 times at the same time, enter the sixth generation unit; otherwise, put the unit with the largest interaction index between the generator and the DC converter station into use, form a new startup mode, and calculate the interaction index between the generator and the DC converter station and the multi-infeed DC commutation failure again, until the single-loop DC commutation failure is less than 2 times and the multiple DC commutation failures are less than 2 times at the same time;

[0065] The sixth generating unit 260 is used to form a minimum startup plan taking into account voltage stability and DC commutation failure.

[0066] A possible implementation manner is provided in an embodiment of the present application, where 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] A possible implementation manner is provided in an embodiment of the present application, where 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 is the short-circuit capacity of the DC converter station busbar after the i-th generator is removed, P 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 change amplitude of bus voltage of the i-th generator booster station after DC blocking.

[0074] A possible implementation manner is provided in an embodiment of the present application, where the fourth generating unit 240 is further configured to:

[0075] Transient voltage stability margin, 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] A possible implementation manner is provided in an embodiment of the present application, where 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 the time Δt, 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] A possible implementation manner is provided in the embodiment of the present application, where 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 the DC k commutation bus, ΔUac j,i ΔU is the voltage change amplitude of DC j commutation bus 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 any one of the above-mentioned embodiments of the minimum startup method of the receiving-end power grid taking into account voltage stability and DC commutation failure.

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

[0089] Those skilled in the art can 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 are not further described here.

[0090] Those skilled in the art can understand that the technical solution of the present application can be essentially or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, which includes a number of program instructions, so that an electronic device (such as a personal computer, a server, or a network device, etc.) executes all or part of the steps of the method described in each embodiment of the present application when running the program instructions. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0091] Alternatively, all or part of the steps of implementing the aforementioned method embodiments may be accomplished by hardware associated with 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 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 multiple DC feed-in receiving-end power grid data; Step S02, forming an initial minimum startup mode; 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 DC blocking condition of serious fault, and sort them; judge whether the regional load active power margin meets the static voltage stability margin requirement under the current startup mode; if yes, 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, calculate the generator static voltage support effect index and static voltage stability margin again, until the static voltage stability margin meets the requirements; form a minimum startup plan taking into account the static voltage stability margin; Step S04, calculating the transient voltage stability margin of the regional receiving-end power grid under different faults in the current startup mode, and sorting 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 sorted; it is determined whether the transient voltage stability margin is positive under the weak section fault; if so, the next step S05 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 of the generator and the transient voltage stability margin are calculated again until the transient voltage stability margin is positive; a minimum startup plan taking into account the transient voltage stability margin is formed; Step S05, calculating the commutation failure of multi-input DC under different AC faults in the current startup mode; calculating the interaction index between the generator and the DC converter station and sorting them; judging the commutation failure of multi-input DC under different AC faults; if the single-circuit DC commutation failure is less than 2 times and the multiple-circuit DC commutation failure is less than 2 times at the same time, then proceeding 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 calculating the interaction index between the generator and the DC converter station and the multi-input DC commutation failure again, until the single-circuit DC commutation failure is less than 2 times and the multiple-circuit DC commutation failure is less than 2 times at the same time; Step S06, forming a minimum startup plan taking into account voltage stability and DC commutation failure.

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

3. The method according to claim 1, characterized in that In step S03, the static voltage support effect index of the i-th generator is calculated by the following formula: 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 is the short-circuit capacity of the DC converter station busbar after the i-th generator is removed, P 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 change amplitude of bus voltage of the i-th generator booster station after DC blocking.

4. The method according to claim 1, characterized in that: In step S04, the transient voltage stability margin is calculated using the following formula: 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.

5. The method according to claim 1, characterized in that In step S04, the transient voltage support effect index of the i-th generator is calculated by the following formula: 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 the time Δt, 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.

6. The method according to claim 1, characterized in that In step S05, the interaction index between the i-th generator and multiple DC converter stations is calculated by the following formula: 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 the DC k commutation bus, ΔUac j,i ΔU is the voltage change amplitude of DC j commutation bus 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.

7. 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, used for forming multi-DC feed-in receiving-end power grid data; A second generating unit, used for forming an initial minimum startup mode; The third generation unit is used to calculate and sort the regional static voltage stability margin after multiple DC faults in the network; The DC corresponding to the minimum static voltage stability margin is taken as the most serious fault DC; the generator static voltage support effect index under the severe 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; 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 different faults under the current startup mode, and sort 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 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; the minimum startup plan taking into account the transient voltage stability margin is formed; The fifth generation unit is used to calculate the commutation failure of multi-input DC under different AC faults in the current startup mode; calculate the interaction index between the generator and the DC converter station and sort them; determine the commutation failure of multi-input DC under different AC faults; if the single-loop DC commutation failure is less than 2 times and the simultaneous commutation failure of multiple DC is less than 2 times, enter the sixth generation unit; otherwise, put the unit with the largest interaction index between the generator and the DC converter station into use, form a new startup mode, and calculate the interaction index between the generator and the DC converter station and the multi-input DC commutation failure again, until the single-loop DC commutation failure is less than 2 times and the simultaneous commutation failure of multiple DC is less than 2 times; The sixth generation unit is used to form a minimum startup plan taking into account voltage stability and DC commutation failure.

8. An electronic device, characterized in that: The invention 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 of the receiving-end power grid taking into account voltage stability and DC commutation failure as described in any one of claims 1 to 6.

9. 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 6 when running.

10. A computer program product, comprising a computer program, characterized in that The computer program is configured to execute, when running, 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 6.

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