Method and device for limiting fault level of power grid through controllable phase shifter

Abstract

The invention discloses a method and device for limiting the fault level of a power grid through a controllable phase shifter, and relates to the technical field of electric power. The method comprises the following steps: monitoring short-circuit current of a power transmission channel with a thermal stability risk in a regional power grid; and according to the short-circuit current, controlling a controllable phase shifter installed on the power transmission channel to jump to a gear corresponding to the short-circuit current so as to reduce the short-circuit level of the fault point of the power transmission channel. According to the method and device for limiting the fault level of the power grid through the controllable phase shifter, the controllable phase shifter is introduced into the power transmission channel with the thermal stability risk of the regional power grid, so that the voltage level of the fault point of the power transmission channel before the fault can be adjusted; effective control over the fault level and the fault range after the short-circuit fault of the power transmission channel occurs is achieved, meanwhile, quick response can be achieved according to the magnitude of short-circuit current, the controllable phase shifter is controlled to act, and therefore the dynamic stability of the system is improved, and the delivery capacity of the limited channel is further improved.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method and a device for limiting a power grid fault level by using a controllable phase shifter. Background Art

[0002] The large-scale access of fluctuating power sources such as photovoltaics and wind power has highlighted the uneven temporal and spatial distribution of the power flow in the new energy transmission channel, the complex and changeable operating conditions, and the dynamic limitation of the transmission capacity, which has brought a series of new challenges to power dispatching and power equipment configuration. In terms of power grid operation, the power flow in the new energy transmission channel is complex and changeable, and the transmission channels shared by new energy and conventional power sources are often limited. Due to the large uncertainty of new energy output, conventional units need to adjust their output frequently, and it is difficult to avoid thermal stability limit problems in shared channels. As a result, the controllability of power grid power flow dispatching is reduced, there is a certain risk of short-circuit faults, and the fault has a large impact range.

[0003] The existing technology mainly adjusts and controls the voltage amplitude, phase and line reactance of nodes and transmission channels in the power grid through power flow control devices, thereby controlling the power flow distribution of the power grid. The existing technology mainly has the following shortcomings:

[0004] Traditional phase-shifting transformers have strong overload capacity, large regulation capacity, good equipment stability and low engineering cost, but they cannot be adjusted continuously and smoothly, have low regulation accuracy, slow speed and no online bidirectional regulation capability. Sen Transformer (ST) can independently control the active and reactive power flow of the system, and achieves power flow regulation performance similar to that of the unified power flow controller (UPFC), which greatly reduces the cost and loss of the device. However, the existence of the tap makes the output voltage of ST discrete, and it is impossible to continuously regulate the line flow. There will be no optional tap switches for the ultra-high voltage and ultra-high voltage levels, that is, the ultra-high voltage and ultra-high voltage lines cannot adopt the Sen transformer technology solution. As typical representatives of all-power electronic power flow regulation equipment, UPFC and SSSC (static synchronous series compensator) have outstanding advantages of fast regulation speed, flexible operation mode, good regulation continuity and high precision, and great technical development potential. The disadvantages are weak overload capacity, complex structure, difficult construction and operation and maintenance, and high cost, which seriously restricts the promotion and application in the current power grid. Existing mechanical and electromagnetic power flow control devices, power electronic power flow control devices, and hybrid power flow control devices all start from the perspective of improving line power flow distribution, and lack an effective method of using controllable phase shifters to reduce short-circuit levels from a voltage perspective.

[0005] This section is intended to provide a background or context to the embodiments of the invention recited in the claims. No admission is made that the description herein is prior art by inclusion in this section. Summary of the invention

[0006] In order to solve the above technical problems, the embodiments of the present invention provide a method and device for limiting the fault level of a power grid by using a controllable phase shifter, which can solve at least part of the above technical problems.

[0007] An embodiment of the present invention provides a method for limiting a power grid fault level by using a controllable phase shifter, comprising:

[0008] Monitor short-circuit currents in transmission corridors where there is a risk of thermal stability in the regional grid;

[0009] According to the short-circuit current, a controllable phase shifter installed on the power transmission channel is controlled to jump to a gear position corresponding to the short-circuit current, so as to reduce the short-circuit level of the fault point of the power transmission channel.

[0010] In some embodiments, the method further comprises:

[0011] Determine, based on the grid parameters and boundary conditions of the regional power grid, a transmission channel where the regional power grid has thermal stability risks;

[0012] The installation position of the controllable phase shifter is determined according to the power transmission channel with thermal stability risk.

[0013] In some embodiments, the grid parameters of the regional power grid include at least one of the following: regional power grid connection mode, new energy model, line parameters, and transformer parameters.

[0014] In some embodiments, determining, based on the grid parameters and boundary conditions of the regional power grid, a transmission channel in which the regional power grid has a thermal stability risk includes:

[0015] According to the grid parameters of the regional power grid, the channel load rate of each transmission channel of the regional power grid is calculated with the boundary conditions that the new energy simultaneous rate of the regional power grid is 50% to 60%, half of the thermal power units of each plant are started or less than half, and the summer load mode is used as the boundary conditions;

[0016] If a three-phase permanent N-1 fault occurs in the double-circuit transmission line of the regional power grid, and the load rate of the remaining single-circuit transmission line is greater than 100% and the load rate of the long-distance single-circuit transmission line is greater than 90%, then the remaining single-circuit transmission line and the long-distance single-circuit transmission line are determined to be transmission channels with potential thermal stability risks.

[0017] In some embodiments, according to the short-circuit current, controlling a controllable phase shifter installed on the power transmission channel to jump to a gear corresponding to the short-circuit current to reduce the short-circuit level of the fault point of the power transmission channel includes:

[0018] Calculating a ratio of the short-circuit current to the maximum rated current carrying capacity of the power transmission channel to obtain a fault indication parameter;

[0019] According to the fault indication parameter, the controllable phase shifter is controlled to jump to a gear position corresponding to the fault indication parameter to reduce the short circuit level of the fault point of the transmission channel, wherein the series voltage injected into the transmission channel by the controllable phase shifter is opposite to the direction of the voltage at the fault point.

[0020] In some embodiments, the method further comprises:

[0021] If the short-circuit fault of the power transmission channel is eliminated, the controllable phase shifter is controlled to jump to a gear position of a normal working state.

[0022] An embodiment of the present invention provides a device for limiting a power grid fault level by using a controllable phase shifter, comprising:

[0023] A monitoring module for monitoring short-circuit currents in transmission channels with thermal stability risks in regional power grids;

[0024] The control module is used to control the controllable phase shifter installed on the power transmission channel to jump to a gear position corresponding to the short-circuit current according to the short-circuit current, so as to reduce the short-circuit level of the fault point of the power transmission channel.

[0025] In some embodiments, the apparatus further comprises:

[0026] A first determination module is used to determine, based on the grid parameters and boundary conditions of the regional power grid, a transmission channel in which the regional power grid has a thermal stability risk;

[0027] The second determination module is used to determine the installation position of the controllable phase shifter according to the power transmission channel with thermal stability risk.

[0028] In some embodiments, the grid parameters of the regional power grid include at least one of the following: regional power grid connection mode, new energy model, line parameters, and transformer parameters.

[0029] In some embodiments, the first determining module is specifically configured to:

[0030] According to the grid parameters of the regional power grid, the channel load rate of each transmission channel of the regional power grid is calculated with the boundary conditions that the new energy simultaneous rate of the regional power grid is 50% to 60%, half of the thermal power units of each plant are started or less than half, and the summer load mode is used as the boundary conditions;

[0031] If a three-phase permanent N-1 fault occurs in the double-circuit transmission line of the regional power grid, and the load rate of the remaining single-circuit transmission line is greater than 100% and the load rate of the long-distance single-circuit transmission line is greater than 90%, then the remaining single-circuit transmission line and the long-distance single-circuit transmission line are determined to be transmission channels with potential thermal stability risks.

[0032] In some embodiments, the control module is specifically used to:

[0033] Calculating a ratio of the short-circuit current to the maximum rated current carrying capacity of the power transmission channel to obtain a fault indication parameter;

[0034] According to the fault indication parameter, the controllable phase shifter is controlled to jump to a gear position corresponding to the fault indication parameter to reduce the short circuit level of the fault point of the transmission channel, wherein the series voltage injected into the transmission channel by the controllable phase shifter is opposite to the direction of the voltage at the fault point.

[0035] In some embodiments, the control module is further configured to:

[0036] If the short-circuit fault of the power transmission channel is eliminated, the controllable phase shifter is controlled to jump to a gear position of a normal working state.

[0037] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for limiting the fault level of a power grid by a controllable phase shifter as described in any of the above embodiments is implemented.

[0038] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for limiting the fault level of a power grid by using a controllable phase shifter as described in any of the above embodiments is implemented.

[0039] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the method for limiting the fault level of a power grid by using a controllable phase shifter as described in any of the above embodiments is implemented.

[0040] The method and device for limiting the fault level of a power grid by a controllable phase shifter provided in an embodiment of the present invention introduces a controllable phase shifter into a transmission channel where there is a thermal stability risk in a regional power grid. In this way, the pre-fault voltage level of the fault point of the transmission channel can be adjusted to achieve effective control of the fault level and fault range after a short-circuit fault of the transmission channel occurs. At the same time, the controllable phase shifter can be controlled to respond quickly according to the magnitude of the short-circuit current, thereby improving the dynamic stability of the system and further enhancing the transmission capacity of the restricted channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0042] Figure 1 A schematic flow chart of a method for limiting a power grid fault level by using a controllable phase shifter provided in an embodiment of the present invention.

[0043] Figure 2 A partial flow chart of a method for limiting a power grid fault level by using a controllable phase shifter provided in an embodiment of the present invention.

[0044] Figure 3 A partial flow chart of a method for limiting a power grid fault level by using a controllable phase shifter provided in an embodiment of the present invention.

[0045] Figure 4 A partial flow chart of a method for limiting a power grid fault level by using a controllable phase shifter provided in an embodiment of the present invention.

[0046] Figure 5 A schematic diagram of the structure of a device for limiting a power grid fault level through a controllable phase shifter provided in an embodiment of the present invention.

[0047] Figure 6 A partial structural diagram of a device for limiting a power grid fault level through a controllable phase shifter provided in an embodiment of the present invention.

[0048] Figure 7 A schematic diagram of the physical structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0050] The information collected in the technical solution of the present invention is information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of the relevant data comply with the relevant laws, regulations and standards of the relevant countries and regions, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0051] The acquisition, transmission, storage, use, and processing of data in the technical solution of the present invention are in compliance with the relevant provisions of national laws and regulations.

[0052] It should be noted that in the embodiments of the present invention, certain software, components, models and other existing solutions in the industry may be mentioned, which should be regarded as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present invention, but it does not mean that the inventor has or will necessarily use the solution.

[0053] The method for limiting the fault level of a power grid by using a controllable phase shifter provided in an embodiment of the present invention is executed by a subject including but not limited to a computer.

[0054] Figure 1 FIG. 1 is a flow chart of a method for limiting a power grid fault level by a controllable phase shifter provided by an embodiment of the present invention, such as Figure 1 As shown, the method for limiting the fault level of a power grid by using a controllable phase shifter provided in an embodiment of the present invention includes:

[0055] S100, monitor the short-circuit current of the transmission channels with thermal stability risks in the regional power grid;

[0056] In step S100, transmission channels in the regional power grid with thermal stability risks (such as long-term overloaded channels in the regional power grid and sections that exceed thermal stability limits and other weak links in power grid operation) can be determined in advance. After the transmission channels in the regional power grid with thermal stability risks are determined, the current of the transmission channels can be monitored in real time. When the current in the transmission channel exceeds a set value, it can be considered that a short-circuit fault has occurred in the transmission channel, and the current at this time is a short-circuit current.

[0057] S200. According to the short-circuit current, control a controllable phase shifter installed on the power transmission channel to jump to a gear position corresponding to the short-circuit current, so as to reduce the short-circuit level of the fault point of the power transmission channel.

[0058] In step S200, there may be multiple transmission channels with thermal stability risks in the regional power grid. When there are multiple transmission channels with thermal stability risks, a controllable phase shifter is installed on each of the transmission channels. When a short circuit fault occurs in one of the transmission channels, the controllable phase shifter installed on the transmission channel is controlled to jump to a gear corresponding to the short circuit current according to the short circuit current of the transmission channel, so as to reduce the short circuit level of the fault point of the transmission channel.

[0059] Specifically, the transmission channel equipped with the controllable phase shifter can be equivalent to the series connection of an ideal transformer with a complex turns ratio and a line. The mathematical model is as follows:

[0060]

[0061] Where: Ii Inject current into node i, I j Inject current into node j, U i is the line voltage at node i, U j is the line voltage at node j, Y ij is the admittance of the line corresponding to nodes i and j, and Y is the equivalent admittance of the controllable phase shifter.

[0062] When a fault occurs, the fault current limiting principle is based on impedance control. By adjusting the voltage amplitude and phase angle injected by the controllable phase shifter, the overall equivalent impedance is changed. Before the controllable phase shifter is compensated, the pre-fault voltage U F as follows:

[0063]

[0064] Where: Y1 is the admittance on the left side of the fault point, and Y2 is the admittance on the right side of the fault point.

[0065] After compensation by the controllable phase shifter, the voltage U before the fault point F ,as follows:

[0066]

[0067] Where: Y0 is the series equivalent admittance of the left side admittance of the fault point and the admittance of the controllable phase shifter.

[0068] According to the superposition theorem, after being limited by the controllable phase shifter (after the controllable phase shifter jumps to the gear corresponding to the short-circuit current), the voltage U CF as follows:

[0069] U CF =U F +U F '

[0070]

[0071] By adjusting the series voltage U injected by the controllable phase shifter s , so that U F with U F′ The direction is opposite, and U s The amplitude is maximized as much as possible to reduce the voltage level at the fault point, thereby effectively reducing the short circuit level at the fault point.

[0072] The method for limiting the fault level of a power grid by using a controllable phase shifter provided in an embodiment of the present invention introduces a controllable phase shifter into a transmission channel where there is a thermal stability risk in a regional power grid. In this way, the pre-fault voltage level of the fault point of the transmission channel can be adjusted to achieve effective control of the fault level and fault range after a short-circuit fault of the transmission channel occurs. At the same time, the controllable phase shifter can be controlled to respond quickly according to the magnitude of the short-circuit current, thereby improving the dynamic stability of the system and further enhancing the transmission capacity of the restricted channel.

[0073] like Figure 2 As shown, in some embodiments, the method further includes:

[0074] S300, determining, based on the grid parameters and boundary conditions of the regional power grid, a power transmission channel in which the regional power grid has a thermal stability risk;

[0075] In step S300, the grid parameters of the regional power grid can be obtained based on the annual grid mode data. The grid parameters use measured data and measured models, and the parameters that cannot be obtained use typical parameters or empirical values. The annual grid mode data refers to the technical plan created by the power system operation and dispatching department to guide the production and operation of the power system in the next year.

[0076] The boundary conditions of a regional power grid refer to the parameters and conditions that define the interaction or exchange between the regional power grid and the external system in the operation and planning of the power system, such as transmission capacity limitations, voltage levels, stability requirements, etc.

[0077] After obtaining the grid parameters and boundary conditions of the regional power grid, the weak links in the operation of the regional power grid, such as the long-term overload channels and sections that exceed the thermal stability limits, are evaluated based on the grid parameters and boundary conditions. Based on these weak links in the operation of the regional power grid, the transmission channels in the regional power grid that have thermal stability risks are determined.

[0078] S400: Determine an installation position of a controllable phase shifter according to the power transmission channel with thermal stability risk.

[0079] In step S400, for each power transmission channel having a thermal stability risk, a controllable phase shifter is installed at a corresponding position of the power transmission channel.

[0080] In some embodiments, the grid parameters of the regional power grid may include at least one of the following: regional power grid connection mode, new energy model, line parameters, and transformer parameters.

[0081] like Figure 3 As shown, in some embodiments, the above step S300 may include:

[0082] S301. Calculate the channel load rate of each transmission channel of the regional power grid according to the grid parameters of the regional power grid, with the boundary conditions that the new energy simultaneous rate of the regional power grid is 50% to 60%, half of the thermal power units of each plant are started or less than half, and the summer load mode;

[0083] In step S301, grid parameters such as the connection mode of the regional power grid, the new energy model, the line parameters, and the transformer parameters can be obtained based on the annual data of the power grid. The grid parameters use the measured data and the measured model, and the parameters that cannot be obtained use the typical parameters or empirical values. The large generation of new energy in the regional power grid (the simultaneous rate of new energy is 50% to 60%), the small generation of thermal power units (half of the thermal power units in each plant are turned on or less than half of them), and the summer load mode are selected as boundary conditions to calculate the channel load rate of each transmission channel of the regional power grid.

[0084] The channel load rate calculation formula can be as follows:

[0085]

[0086] Where: λ is the channel load rate, P s is the channel active power, U s is the system reference voltage, I s is the rated current of the line, and cosφ is the power factor angle.

[0087] S302. If a three-phase permanent N-1 fault occurs in a double-circuit transmission line of the regional power grid, and the load rate of the remaining single-circuit transmission line is greater than 100% and the load rate of the long-distance single-circuit transmission line is greater than 90%, then the remaining single-circuit transmission line and the long-distance single-circuit transmission line are determined to be transmission channels with potential thermal stability risks.

[0088] In step S302, it can be considered that after a three-phase permanent N-1 fault occurs in a double-circuit transmission line, the lines with a remaining single-circuit channel load rate greater than 100%, and the long-distance single-circuit transmission line load rate close to 100%, that is, the lines with potential thermal stability risks are overloaded lines. The above channels are selected to be equipped with controllable phase shifters and protection control devices. The protection control device is used to monitor the short-circuit current of the transmission channel, and according to the short-circuit current, control the controllable phase shifter on the transmission channel to jump to the gear corresponding to the short-circuit current, so as to reduce the short-circuit level of the fault point of the transmission channel.

[0089] like Figure 4 As shown, in some embodiments, the above step S200 may include:

[0090] S201, calculating the ratio of the short-circuit current to the maximum rated current carrying capacity of the power transmission channel to obtain a fault indication parameter;

[0091] In step S201, when a short circuit fault occurs in the transmission channel, the protection control device installed in the transmission channel can respond quickly according to the magnitude of the short circuit current, calculate the ratio of the short circuit current to the maximum rated current of the transmission channel, and obtain a fault indication parameter. The calculation formula of the fault indication parameter is as follows:

[0092]

[0093] Where: I f is the line short-circuit current, I Lmax It is the maximum rated current of the line.

[0094] S202. According to the fault indication parameter, control the controllable phase shifter to jump to a gear position corresponding to the fault indication parameter to reduce the short circuit level of the fault point of the transmission channel, wherein the series voltage injected into the transmission channel by the controllable phase shifter is opposite to the direction of the voltage at the fault point.

[0095] In step S202, when tanθ<1, there is no short circuit fault in the transmission channel, the protection control device does not respond, and the controllable phase shifter does not operate; when tanθ≥1, the protection control device quickly sends an action signal to the controllable phase shifter of the transmission channel. And due to the characteristics of the tangent function, when tanθ≥1, that is, θ∈[45°, 90), tanθ increases significantly as the value of θ increases. It is expressed as When f The larger it is, the stronger the signal sent by the protection control device, and the controllable phase shifter jumps to a higher gear.

[0096] In some embodiments, the method may further include: if the short-circuit fault of the power transmission channel is eliminated, controlling the controllable phase shifter to jump to a gear position of a normal working state.

[0097] Specifically, when the short-circuit fault is eliminated, the protection control device no longer sends an action signal, the voltage injected by the controllable phase shifter returns to normal amplitude and phase angle, and the system resumes normal operation.

[0098] In order to better understand the present invention, the method for limiting the fault level of a power grid by using a controllable phase shifter provided by the present invention is described in detail below through a specific embodiment.

[0099] This embodiment provides a method for limiting a short-circuit fault level of a power grid by using a controllable phase shifter, the method comprising:

[0100] Step 1: Determine the grid parameters and boundary conditions, calculate the regional power flow distribution, voltage level and load rate, screen the weak links of the power grid such as heavy-load channels and single-circuit long-distance channels, and determine the installation location of the controllable phase shifter.

[0101] Step 2: When a short circuit fault occurs in the system, the protection control device detects that the fault current exceeds the set value, transmits an action signal, and controls the controllable phase shifter to respond quickly.

[0102] Step 3: Calculate the system equivalent impedance based on the fault point location and the controllable phase shifter installation location. According to the equivalent impedance, adjust the series voltage amplitude and phase injected by the controllable phase shifter to limit the short-circuit current to a lower value, thereby reducing the overall fault level.

[0103] Step 4: After the fault is eliminated, the controllable phase shifter returns to the normal phase angle and the system resumes normal operation.

[0104] It can be seen that this embodiment introduces controllable phase shifters in weak links of power grid operation such as long-term overload channels of regional power grids and sections that exceed thermal stability limits, and at the same time adds a protection control device that can respond quickly according to the magnitude of the fault current, solving the problem that the controllable phase shifter cannot act in time due to receiving action instructions too slowly, causing the circuit breaker to act first. In addition, this embodiment provides a method for limiting the level of short-circuit faults using a controllable phase shifter, which effectively reduces the magnitude of the short-circuit current after the fault occurs by limiting the voltage at the fault point before the fault, solving the problem of low channel transmission capacity due to weak channels. It effectively reduces the level of faults and the scope of impact, which is of great significance to improving the reliable and stable operation of new power systems.

[0105] Based on the same inventive concept, an embodiment of the present invention further provides a device for limiting the level of a power grid fault by a controllable phase shifter, as described in the following embodiments. Since the principle of solving the problem by the device is similar to the method for limiting the level of a power grid fault by a controllable phase shifter, the implementation of the device can refer to the implementation of the method for limiting the level of a power grid fault by a controllable phase shifter, and the repeated parts will not be repeated.

[0106] like Figure 5 As shown, an embodiment of the present invention provides a device for limiting a power grid fault level by using a controllable phase shifter, comprising:

[0107] A monitoring module 21, for monitoring short-circuit current of a transmission channel with thermal stability risk in a regional power grid;

[0108] The control module 22 is used to control the controllable phase shifter installed on the power transmission channel to jump to a gear position corresponding to the short-circuit current according to the short-circuit current, so as to reduce the short-circuit level of the fault point of the power transmission channel.

[0109] like Figure 6 As shown, in some embodiments, the device further includes:

[0110] A first determination module 23 is used to determine, based on the grid parameters and boundary conditions of the regional power grid, a transmission channel in which the regional power grid has a thermal stability risk;

[0111] The second determination module 24 is used to determine the installation position of the controllable phase shifter according to the power transmission channel with thermal stability risk.

[0112] In some embodiments, the grid parameters of the regional power grid include at least one of the following: regional power grid connection mode, new energy model, line parameters, and transformer parameters.

[0113] In some embodiments, the first determining module 23 is specifically configured to:

[0114] According to the grid parameters of the regional power grid, the channel load rate of each transmission channel of the regional power grid is calculated with the boundary conditions that the new energy simultaneous rate of the regional power grid is 50% to 60%, half of the thermal power units of each plant are started or less than half, and the summer load mode is used as the boundary conditions;

[0115] If a three-phase permanent N-1 fault occurs in the double-circuit transmission line of the regional power grid, and the load rate of the remaining single-circuit transmission line is greater than 100% and the load rate of the long-distance single-circuit transmission line is greater than 90%, then the remaining single-circuit transmission line and the long-distance single-circuit transmission line are determined to be transmission channels with potential thermal stability risks.

[0116] In some embodiments, the control module 22 is specifically used to:

[0117] Calculating a ratio of the short-circuit current to the maximum rated current carrying capacity of the power transmission channel to obtain a fault indication parameter;

[0118] According to the fault indication parameter, the controllable phase shifter is controlled to jump to a gear position corresponding to the fault indication parameter to reduce the short circuit level of the fault point of the transmission channel, wherein the series voltage injected into the transmission channel by the controllable phase shifter is opposite to the direction of the voltage at the fault point.

[0119] In some embodiments, the control module 22 is further configured to:

[0120] If the short-circuit fault of the power transmission channel is eliminated, the controllable phase shifter is controlled to jump to a gear position of a normal working state.

[0121] Figure 7 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention, such as Figure 7 As shown, the electronic device 003 includes a processor 301, a memory 302 and a bus 303. The processor 301 and the memory 302 communicate with each other via the bus 303.

[0122] The processor 301 is used to call the program instructions in the memory 302 to execute the methods provided by the above method embodiments.

[0123] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for limiting the fault level of a power grid by using a controllable phase shifter is implemented.

[0124] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the method for limiting the fault level of a power grid by using a controllable phase shifter is implemented.

[0125] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0126] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0127] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0128] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0129] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for limiting the level of power grid faults by means of a controllable phase shifter, characterized in that: include: Monitor short-circuit currents in transmission corridors where there is a risk of thermal stability in the regional grid; According to the short-circuit current, a controllable phase shifter installed on the power transmission channel is controlled to jump to a gear position corresponding to the short-circuit current, so as to reduce the short-circuit level of the fault point of the power transmission channel.

2. The method according to claim 1, characterized in that: The method further comprises: Determine, based on the grid parameters and boundary conditions of the regional power grid, a transmission channel where the regional power grid has thermal stability risks; The installation position of the controllable phase shifter is determined according to the power transmission channel with thermal stability risk.

3. The method according to claim 2, characterized in that The grid parameters of the regional power grid include at least one of the following: regional power grid connection mode, new energy model, line parameters, and transformer parameters.

4. The method according to claim 2 or 3, characterized in that: According to the grid parameters and boundary conditions of the regional power grid, the transmission channels of the regional power grid with thermal stability risks are determined, including: According to the grid parameters of the regional power grid, the channel load rate of each transmission channel of the regional power grid is calculated with the boundary conditions that the new energy simultaneous rate of the regional power grid is 50% to 60%, half of the thermal power units of each plant are started or less than half, and the summer load mode is used as the boundary conditions; If a three-phase permanent N-1 fault occurs in the double-circuit transmission line of the regional power grid, and the load rate of the remaining single-circuit transmission line is greater than 100% and the load rate of the long-distance single-circuit transmission line is greater than 90%, then the remaining single-circuit transmission line and the long-distance single-circuit transmission line are determined to be transmission channels with potential thermal stability risks.

5. The method according to claim 1, characterized in that According to the short-circuit current, controlling a controllable phase shifter installed on the power transmission channel to jump to a gear position corresponding to the short-circuit current to reduce the short-circuit level of the fault point of the power transmission channel includes: Calculating a ratio of the short-circuit current to the maximum rated current carrying capacity of the power transmission channel to obtain a fault indication parameter; According to the fault indication parameter, the controllable phase shifter is controlled to jump to a gear position corresponding to the fault indication parameter to reduce the short circuit level of the fault point of the transmission channel, wherein the series voltage injected into the transmission channel by the controllable phase shifter is opposite to the direction of the voltage at the fault point.

6. The method according to claim 1, characterized in that The method further comprises: If the short-circuit fault of the power transmission channel is eliminated, the controllable phase shifter is controlled to jump to a gear position of a normal working state.

7. A device for limiting the level of power grid faults by means of a controllable phase shifter, characterized in that: include: A monitoring module for monitoring short-circuit currents in transmission channels with thermal stability risks in regional power grids; The control module is used to control the controllable phase shifter installed on the power transmission channel to jump to a gear position corresponding to the short-circuit current according to the short-circuit current, so as to reduce the short-circuit level of the fault point of the power transmission channel.

8. The device according to claim 7, characterized in that The device also includes: A first determination module is used to determine, based on the grid parameters and boundary conditions of the regional power grid, a transmission channel in which the regional power grid has a thermal stability risk; The second determination module is used to determine the installation position of the controllable phase shifter according to the power transmission channel with thermal stability risk.

9. The device according to claim 8, characterized in that The grid parameters of the regional power grid include at least one of the following: regional power grid connection mode, new energy model, line parameters, and transformer parameters.

10. The device according to claim 8 or 9, characterized in that The first determining module is specifically used for: According to the grid parameters of the regional power grid, the channel load rate of each transmission channel of the regional power grid is calculated with the boundary conditions that the new energy simultaneous rate of the regional power grid is 50% to 60%, half of the thermal power units of each plant are started or less than half, and the summer load mode is used as the boundary conditions; If a three-phase permanent N-1 fault occurs in the double-circuit transmission line of the regional power grid, and the load rate of the remaining single-circuit transmission line is greater than 100% and the load rate of the long-distance single-circuit transmission line is greater than 90%, then the remaining single-circuit transmission line and the long-distance single-circuit transmission line are determined to be transmission channels with potential thermal stability risks.

11. The device according to claim 7, characterized in that The control module is specifically used for: Calculating a ratio of the short-circuit current to the maximum rated current carrying capacity of the power transmission channel to obtain a fault indication parameter; According to the fault indication parameter, the controllable phase shifter is controlled to jump to a gear position corresponding to the fault indication parameter to reduce the short circuit level of the fault point of the transmission channel, wherein the series voltage injected into the transmission channel by the controllable phase shifter is opposite to the direction of the voltage at the fault point.

12. The device according to claim 7, characterized in that The control module is also used for: If the short-circuit fault of the power transmission channel is eliminated, the controllable phase shifter is controlled to jump to a gear position of a normal working state.

13. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

15. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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