10kv urban distribution network closing loop operation method and system

Abstract

The application provides a 10kV urban distribution network closing loop operation method and system, and belongs to the technical field of distribution network closing loop operation. The method comprises the following steps: establishing a power grid topology graph, selecting two lines needing to be closed i 、 j ; performing closing loop simulation calculation of closing loop impulse current and closing loop steady-state current; judging according to auxiliary judgment conditions; when the judgment result is that the closing loop operation can be performed, performing the closing loop operation, and generating a path information graph after the closing loop; at t1, t2 and t3 moments after the closing loop operation of the line i 、 j is performed, verifying the steady-state current on the line based on the first-stage switch protection II segment setting value I II , and judging whether the current value is higher than 80% I i , I t1 、 I t2 、 I t3 . If the current value is not higher than 80% I II for three times, the line operation mode is adjusted to reduce the overload trip risk.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power distribution network closing operation, in particular to a 10kV urban power distribution network closing operation method and system. BACKGROUND

[0002] The power distribution network closing refers to that two power distribution lines are respectively carried by the low-voltage side bus of two substations, and the feeder lines are provided with a tie switch and a knife switch. In the normal operation mode, the low-voltage bus of the two substations respectively carries the corresponding power distribution line, and the tie switch is in the open state. When the whole or part of the line of one of the feeder lines has a power failure work, the tie switch and the knife switch are first closed, and then the outgoing switch or the sectionalizing switch is opened, so that the power load of the whole or part of the line is carried by the other feeder line, thereby ensuring uninterrupted power supply.

[0003] Before the closing operation, it is necessary to confirm whether the closing point on both sides has the closing condition. Generally, it is considered that the voltage difference of the two substation feeder lines is within 20% to have the closing condition. However, after the closing, the 10KV line transfers a large amount of high-voltage system load, and the 10KV system has the risk of overload trip, which is extremely likely to cause the 10KV equipment starting protection action in a short time. If the steady-state current after the closing exceeds the maximum carrying capacity of the line, the equipment on the line will be burned out, which will challenge the safe and reliable power use of the user, and there is a great safety hazard to the personnel and equipment themselves. SUMMARY

[0004] Therefore, the present application provides a 10kV urban power distribution network closing operation method and system, which adjusts the line when it is judged that the system has the risk of overload trip by monitoring the system load after the closing, so as to reduce the trip probability after the closing and improve the power reliability.

[0005] The technical solution adopted by the embodiment of the present application to solve the technical problem is:

[0006] A 10kV urban power distribution network closing operation method, comprising:

[0007] Step S1, establishing a power grid topology map, and selecting two lines i and j that need to be closed;

[0008] Step S2, querying the parameters of the closing path and the closing switch, and obtaining the voltage and power parameters of the two lines before the closing, and performing closing simulation calculation of the closing impulse current and the closing steady-state current;

[0009] Step S3: Determine whether a loop closing operation can be performed based on auxiliary discrimination conditions. The auxiliary discrimination conditions include: the phase angle difference between the two sides of the loop closing point is less than 20 degrees, the voltage difference between the two sides of the loop closing point is less than 20%, the loop closing inrush current is less than the switch protection setting value, and the loop closing steady-state current is less than the maximum load capacity of the line. The switch protection settings and corresponding protection functions of each section switch in the line are not all the same.

[0010] Step S4: When the result of step S3 indicates that the loop merging operation can be performed, the loop merging operation is executed, and a path information diagram after loop merging is generated, and the power flow distribution after loop merging is calculated.

[0011] Step S5: Based on the path information map and the distribution of automated switches, re-model and calculate the automated switch settings and automatically send them to the equipment operation and maintenance unit;

[0012] Step S6, at time t1 after the loop closing operation of lines i and j is completed, based on the setting value I of the second stage of the line primary switch protection. II Verify the steady-state current I on line i t1 ; where, if I is satisfied t1 ≥80%I II Then it is confirmed that the system is in a safe and stable operating state after the loop is closed; if I t1 <80%I II If so, it is confirmed that the system is not in a safe and stable operating state after the loop is closed, and there is a risk of overload tripping;

[0013] Step S7, in I t1 <80%I II In the following case, at time t2 after the loop closing operation is completed, based on the setting I of the second stage of the line primary switch protection... II Verify the steady-state current I on the line t2 ;

[0014] Step S8, in I t2 <80%I II In the following case, at time t3 after the loop closing operation is completed, based on the setting I of the second stage of the line primary switch protection... II Verify the steady-state current I on the line t3 ;if I t3 <80%I II This confirms that the system always carries the risk of overload tripping after the loop is closed;

[0015] Step S9, in I t3 <80%I II In such cases, adjust the line operation mode to reduce the risk of overload tripping;

[0016] The specific implementation of step S9, adjusting the line operation mode, includes:

[0017] Step S91: Adjust the setting value of the first-stage switch II of the line by increasing the setting value of the first-stage switch II by 5%.

[0018] or,

[0019] Step S92: Select line k that has multiple connections with line j to perform loop closing, wherein the loop closing process adopts the steps described in steps S1-S5.

[0020] Step S93: Select a cut-off point on the line between lines i and j, and cut off line j. The sectionalizing switch corresponding to the cut-off point is located between lines k and j.

[0021] Preferably, step S2 includes:

[0022] Step S21: Establish an equivalent circuit including lines i and j according to the power grid topology. The equivalent circuit is the distribution loop equivalent network obtained by equivalently retaining the 10kV bus and feeder to the loop point of the substation for the part above the 10kV bus.

[0023] Step S22, calculate the closed-loop steady-state current.

[0024]

[0025]

[0026]

[0027] Z S =R0+jX0+R i +jX i +R j +jX j

[0028] In the formula: The initial currents of feeders i and j before the loop is closed; These are the voltage values ​​on both sides of the loop closure point; After the loop is closed, due to the voltage at the loop closure point The loop current caused by the inequality; R0 and X0 are the equivalent impedances of the portion above the 10kV bus; R i X i The equivalent resistance and reactance of the 10kV feeder i; R j X j The equivalent resistance and reactance of the 10kV feeder j;

[0029]

[0030]

[0031] In the formula: P i Q i P represents the initial active power and initial reactive power of 10kV feeder i. j Q j For the initial active power and initial reactive power of 10kV feeder j, U N The rated voltage U of the 10kV line N =10.5kV, r is the resistance per unit length of the line, x is the reactance per unit length of the line, L i L is the total length from the substation busbar to the loop closing point of feeder i. j The total length from the substation busbar to the loop closing point to which feeder j belongs;

[0032] Step S23, calculate the closed-loop impact current I. P :

[0033] I P =kI1

[0034] In the formula, I1 is the closed-loop steady-state current. The effective value of , k is the maximum impact coefficient, which takes the value of 1.62.

[0035] Preferably, the preset scheme for each switch protection setting in step S3 includes:

[0036] The switch protection settings include current settings and time settings, and the protection function is trip protection or sending alarm messages to the main station of the automation system.

[0037] In the protection settings of the primary switch, the current setting is: substation outgoing switch protection setting / anti-coordination coefficient; the time setting is: substation outgoing switch protection setting - ΔT, where ΔT is the time step difference.

[0038] In the protection settings of the n-stage sectionalizing switches located after the primary switch, the current setting is: protection setting of the (n-1)th sectionalizing switch / anti-coordination coefficient, where n ≥ 2. When n = 2, it is calculated based on the protection setting of the primary switch, and the anti-coordination coefficient is less than 1.5. The time setting is: protection setting of the (n-1)th sectionalizing switch - ΔT, where ΔT is the time difference. When n = 2, it is calculated based on the protection setting of the primary switch, and the time difference is between 0.1s and 0.2s.

[0039] The protection functions of the primary switch include trip protection and alarm;

[0040] When there are branch switches under the nth section switch, the protection functions of the nth section switch include trip protection and alarm.

[0041] When the nth section switch does not have a branch switch, the protection function of the nth section switch includes an alarm.

[0042] Preferably, the counterfitting coefficient is 1.1, and the time interval is 0.1s.

[0043] Preferably, when the condition that the phase angle difference on both sides of the closing point in the auxiliary discrimination condition is less than 20 degrees is not met, the corresponding solution is to adjust the generator parameters.

[0044] When the condition that the voltage difference on both sides of the closing point in the auxiliary discrimination condition is less than 20% is not met, the corresponding solution is to adjust the voltage of the upper-level substation.

[0045] When the condition that the closing impact current in the auxiliary discrimination condition is less than the switch protection setting value is not met, the corresponding solution is to adjust the output of the power generation side and the line current.

[0046] When the condition that the closing steady-state current in the auxiliary discrimination condition is less than the maximum load capacity of the line is not met, the corresponding solution is to adjust the output of the power generation side and the line current.

[0047] Preferably, the line first-level switch protection II section setting value I II is an overcurrent setting value; t1 is the time point at 30 minutes after the closing, t2 is the time point at 60 minutes after the closing, and t3 is the time point at 120 minutes after the closing.

[0048] Preferably, after the step S5 and before the step S6, the method further comprises the following step S10: if the result of the step S3 is that the closing operation cannot be performed, issuing a warning, prompting the failure reason, and generating a solution; the solution includes adjusting the voltage of the upper-level substation, adjusting the output of the power generation side and the line current, and adjusting the generator parameters.

[0049] Further, the application provides a 10kV urban distribution network closing operation method system for executing the above method.

[0050] From the above technical solutions, the 10kV urban distribution network closing loop operation method provided by the embodiment of the application firstly establishes a power grid topology graph, selects two lines i and j that need to be closed loop; queries the closing loop path and the parameter information of the closing loop switch, and obtains the voltage and power parameters of the two lines before closing loop, and performs closing loop simulation calculation of the closing loop impulse current and the closing loop steady-state current; determines whether the closing loop operation can be performed according to the auxiliary discrimination condition, wherein the auxiliary discrimination condition includes that the phase angle difference on both sides of the closing loop point is less than 20 degrees, the voltage difference on both sides of the closing loop point is less than 20%, the closing loop impulse current is less than the switch protection setting value, and the closing loop steady-state current is less than the maximum load capacity of the line; wherein the switch protection setting values of each sectional switch in the line and the corresponding protection functions are not all the same; when the determination result is that the closing loop operation can be performed, the closing loop operation is performed, the path information graph after closing loop is generated, and the power flow distribution after closing loop is calculated; according to the path information graph and the distribution of the automatic switch, the automatic switch setting value is recalculated and automatically issued to the equipment operation and maintenance unit; at the t1, t2 and t3 moments after the closing loop operation of the lines i and j is completed, based on the II section setting value of the first-level switch protection of the line II The steady-state current I on the line i is checked t1 , I t2 , I t3 is determined, if the current value is higher than 80% I II for three times, the line operation mode is adjusted to reduce the overload trip risk. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 is a flow chart of the 10kV urban distribution network closing loop operation method of the application.

[0052] Figure 2 is a distribution network closing loop schematic diagram.

[0053] Figure 3 is a distribution network closing loop equivalent network diagram.

[0054] Figure 4 is a 10kV feeder load uniform distribution model diagram.

[0055] Figure 5 is an auxiliary discrimination program principle architecture diagram.

[0056] Figure 6 is a closing loop operation flow chart using an auxiliary program.

[0057] Figure 7 is an electronic device block diagram for implementing the 10kV urban distribution network closing loop operation method of the application. DETAILED DESCRIPTION

[0058] The technical solutions and technical effects of the present application are further described in detail below in combination with the drawings of the present application.

[0059] As shown in Figure 1 , the present application provides a 10kV urban distribution network closing loop operation method, comprising:

[0060] Step S1, establishing a power grid topology map, selecting two lines i, j that need to be closed loop;

[0061] Step S2, querying the path and parameter information of the closing loop switch, and obtaining the voltage and power parameters of the two lines before closing loop, and performing closing loop simulation calculation of closing loop impulse current and closing loop steady-state current;

[0062] Step S3, judging whether the closing loop operation can be performed according to the auxiliary judgment condition, wherein the auxiliary judgment condition includes: the phase angle difference on both sides of the closing loop point is less than 20 degrees, the voltage difference on both sides of the closing loop point is less than 20%, the closing loop impulse current is less than the switch protection setting value, and the closing loop steady-state current is less than the maximum load capacity of the line; wherein the switch protection setting value and the corresponding protection function of each sectional switch in the line are not the same;

[0063] Step S4, when the judgment result of step S3 is that the closing loop operation can be performed, performing the closing loop operation, generating the path information map after closing loop, and calculating the power flow distribution after closing loop; in addition, if the judgment result of step S3 is that the closing loop operation cannot be performed, issuing a warning, prompting the failure reason, and generating a solution; the solution includes adjusting the voltage size of the upper-level substation, adjusting the output size and line current of the power generation side, and adjusting the generator parameters.

[0064] Step S5, according to the path information map and the distribution of automatic switches, re-modeling to calculate the automatic switch setting value and automatically issuing it to the equipment operation and maintenance unit;

[0065] Step S6, at time t1 after the closing loop operation of lines i, j is completed, based on the II section setting value of the first-level switch protection of the line II , verifying the steady-state current I t1 on line i; wherein, if I t1 ≥80%I II , it is confirmed that the system is in a safe and stable operation state after closing loop; if I t1 <80%I II , it is confirmed that the system is not in a safe and stable operation state after closing loop, and there is a risk of overload trip;

[0066] Step S7, in the case of I t1 <80%I II , at time t2 after the closing loop operation is completed, based on the II section setting value of the first-level switch protection of the line IIVerify the steady-state current I on the line t2 ;

[0067] Step S8, in I t2 <80%I II In the following case, at time t3 after the loop closing operation is completed, based on the setting I of the second stage of the line primary switch protection... II Verify the steady-state current I on the line t3 ;if I t3 <80%I II This confirms that the system always carries the risk of overload tripping after the loop is closed;

[0068] Step S9, in I t3 <80%I II In such cases, adjust the line operation mode to reduce the risk of overload tripping;

[0069] Line primary switch protection stage II setting I II The overcurrent setting is t1, which is 30 minutes after the loop is closed; t2 is 60 minutes after the loop is closed; and t3 is 120 minutes after the loop is closed.

[0070] Furthermore, step S9, adjusting the line operation mode, can be done in two ways:

[0071] The first method is to adjust the setting value of the primary switch section II of the line, increasing the setting value of the primary switch section II by 5%; refer to Table 1 for an example:

[0072]

[0073] Table 1

[0074] The second type is:

[0075] Step S92: Select line k that has multiple connections with line j to perform loop closure, wherein the loop closure process adopts steps S1-S5.

[0076] Step S93: Select a cut-off point on the line between lines i and j, cut off line j, and the sectionalizing switch corresponding to the cut-off point is located between lines k and j.

[0077] Step S6: If the result of step S3 is that the loop closure operation cannot be performed, issue an early warning, indicate the reason for the failure, and generate a solution; the solution includes adjusting the voltage of the upstream substation, adjusting the output of the generator and the line current, and adjusting the generator parameters.

[0078] In step S2, regarding the calculation of the closed-loop steady-state current, firstly... Figure 2Topology analysis of the structural diagram shows that the topology from the 10kV busbar to the loop closure point is identical. The portion above the 10kV busbar is part of the ring network, and impedance equivalence can be performed and converted to the 10kV busbar side. Therefore, by equivalently retaining the 10kV busbar and feeders from the substation to the loop closure point, the equivalent distribution loop network is obtained.

[0079] Step S21: Establish an equivalent circuit reference including lines i and j based on the power grid topology. Figure 3 As shown, the equivalent circuit is the distribution loop equivalent network obtained by equivalently retaining the 10kV bus and feeder to the loop point of the substation for the part above the 10kV bus.

[0080] Step S22, calculate the closed-loop steady-state current.

[0081]

[0082] Z S =R0+jX0+R i +jX i +R j +jX j (4)

[0083] In the formula: The initial currents of feeders i and j before the loop is closed; These are the voltage values ​​on both sides of the loop closure point; After the loop is closed, due to the voltage at the loop closure point The loop current caused by the inequality; R0 and X0 are the equivalent impedances of the portion above the 10kV bus; R i X i The equivalent resistance and reactance of the 10kV feeder i; R j X j The equivalent resistance and reactance of the 10kV feeder j;

[0084] The voltages at the two loop closing points are calculated using the following formula:

[0085]

[0086] In the formula: P i Q i P represents the initial active power and initial reactive power of 10kV feeder i. j Q j For the initial active power and initial reactive power of 10kV feeder j, U N The rated voltage U of the 10kV line N =10.5kV, r is the resistance per unit length of the line, x is the reactance per unit length of the line, L iL is the total length of the busbar of the substation to which the feeder i belongs to the loop closing point j L is the total length of the busbar of the substation to which the feeder j belongs to the loop closing point

[0087] Step S23, calculating the loop closing impact current I P :

[0088] I P = kI1 (7)

[0089] In the formula, I1 is the effective value of the loop closing steady-state current , and k is the maximum impact coefficient, and the value is 1.62.

[0090] The preset scheme of the switch protection setting value in step S3 includes:

[0091] The switch protection setting value includes a current setting value and a time setting value, and the protection function is trip protection or sending an alarm message to an automation system master station;

[0092] In the switch protection setting value of the primary switch, the current setting value is: the substation outgoing line switch protection setting value / anti-coordination coefficient; and the time setting value is: the substation outgoing line switch protection setting value-△T, and △T is a time difference;

[0093] In the switch protection setting value of the n-stage sectional switch located after the primary switch, the current setting value is: the (n-1)-th sectional switch protection setting value / anti-coordination coefficient, and n≥2, when n=2, the switch protection setting value based on the primary switch is calculated, and the anti-coordination coefficient takes a value range less than 1.5; and the time setting value is: the (n-1)-th sectional switch protection setting value-△T, and △T is a time difference, when n=2, the switch protection setting value based on the primary switch is calculated; the time difference takes a value range of 0.1s-0.2s; the anti-coordination coefficient takes a value of 1.1, and the time difference takes a value of 0.1s;

[0094] The protection function of the primary switch includes trip protection and alarm;

[0095] The loop closing auxiliary judgment condition adopted by the application includes:

[0096] 1. The phase angle difference on both sides of the loop closing point is less than 20 degrees;

[0097] 2. The voltage difference on both sides of the loop closing point is less than 20%;

[0098] 3. The loop closing impact current is less than the switch protection setting value;

[0099] 4. The loop closing steady-state current is less than the maximum load capacity of the line (the steady-state current after loop closing should be less than the maximum load capacity of the two lines, otherwise the line is easy to burn, and the maximum load capacity of the line can be determined by the model and diameter of the line);

[0100] All auxiliary conditions need to be met to be considered as the loop closing operation can be carried out, when part of the auxiliary conditions is not met, the following scheme is used for adjustment:

[0101] When the n-th section switch has a branch switch under it, the protection function of the n-th section switch includes tripping protection and alarm;

[0102] When the n-th section switch does not have a branch switch under it, the protection function of the n-th section switch includes alarm.

[0103] When the auxiliary discrimination condition that the phase angle difference on both sides of the loop closing point is less than 20 degrees is not met, the corresponding solution is to adjust the generator parameters;

[0104] When the auxiliary discrimination condition that the voltage difference on both sides of the loop closing point is less than 20% is not met, the corresponding solution is to adjust the voltage size of the upper-level substation;

[0105] When the auxiliary discrimination condition that the loop closing impact current is less than the switch protection setting value is not met, the corresponding solution is to adjust the output size of the power generation side and the line current;

[0106] When the auxiliary discrimination condition that the loop closing steady-state current is less than the maximum load capacity of the line is not met, the corresponding solution is to adjust the output size of the power generation side and the line current.

[0107] Further, the present application provides a 10kV urban distribution network loop closing operation method system, which can be carried by software to implement Figure 1 The method shown.

[0108] According to the embodiments of the present disclosure, the present disclosure also provides an electronic device, a readable storage medium and a computer program product.

[0109] Figure 7 A schematic block diagram of an example electronic device 700 that can be used to implement embodiments of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptops, desktops, tablets, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular telephones, smart phones, wearable devices, and other similar computing devices. The components shown here, their connections and relationships, and their functions, are meant to be examples only, and are not intended to limit implementations of the present disclosure described and / or claimed in this document.

[0110] As Figure 7As shown, the device 700 includes a computing unit 701 that can perform various appropriate actions and processes in accordance with a computer program stored in a read-only memory (ROM) 702 or a computer program loaded into a random access memory (RAM) 703 from a storage unit 708. In the RAM 703, various programs and data required for the operation of the device 700 can also be stored. The computing unit 701, the ROM 702, and the RAM 703 are connected to each other through a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0111] A plurality of components in the device 700 are connected to the I / O interface 705, including: an input unit 706, such as a keyboard, a mouse, etc.; an output unit 707, such as various types of displays, speakers, etc.; a storage unit 708, such as a magnetic disk, an optical disk, etc.; and a communication unit 709, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 709 allows the device 700 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0112] The computing unit 701 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 701 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The computing unit 701 performs various methods and processes described above, such as the 10 kV urban distribution network closing operation method. For example, in some embodiments, the 10 kV urban distribution network closing operation method can be implemented as a computer software program that is tangibly embodied in a machine-readable medium, such as the storage unit 708. In some embodiments, part or all of the computer program can be loaded and / or installed on the device 700 via the ROM 702 and / or the communication unit 709. When the computer program is loaded into the RAM 703 and executed by the computing unit 701, one or more steps of the 10 kV urban distribution network closing operation method described above can be performed. Alternatively, in other embodiments, the computing unit 701 can be configured to perform the 10 kV urban distribution network closing operation method by any other appropriate means, such as by means of firmware.

[0113] The various embodiments of the systems and techniques described above can be implemented in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a load programmable logic device (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0114] Program code for carrying out methods of the present disclosure can be written in any combination of one or more programming languages. The program code can be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the program code, when executed by the processor or controller, produces the functions / operations specified in the flowcharts and / or the block diagrams. The program code can be executed entirely on a machine, partially on a machine, partially on a machine as a stand-alone software package, or entirely on a remote machine or server.

[0115] In the context of the present disclosure, a machine-readable medium can be a tangible medium that contains or stores a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include but is not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include one or more lines of electrical conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0116] To provide for interaction with a user, the systems and techniques described here can be implemented on a computer having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0117] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), blockchain network, and the Internet.

[0118] The computer system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0119] The above disclosure is only the preferred embodiment of the present application, of course, cannot be limited by this to limit the scope of the present application, those skilled in the art can understand that the implementation of all or part of the above-mentioned processes, and according to the equivalent changes made by the claims of the present application, still belong to the scope covered by the present application.

Claims

1. A method for closing a loop of a 10 kV urban distribution network, characterized in that, The method comprises the following steps: Step S1, establishing a power grid topology map, and selecting two lines i and j that need to be looped; Step S2, querying the looped path and the parameter information of the looped switch, and obtaining the voltage and power parameters of the two lines before loop, and performing loop simulation calculation of the looped inrush current and the looped steady-state current; Step S3, judging whether the loop operation can be performed according to the auxiliary judgment condition, wherein the auxiliary judgment condition comprises that the phase angle difference on both sides of the loop point is less than 20 degrees, the voltage difference on both sides of the loop point is less than 20%, the loop inrush current is less than the switch protection setting value, and the loop steady-state current is less than the maximum load capacity of the line; wherein the switch protection setting value of each sectional switch in the line and the corresponding protection function are not the same; Step S4, when the judgment result of step S3 is that the loop operation can be performed, performing the loop operation, generating the path information map after the loop, and calculating the power flow distribution after the loop; Step S5, according to the path information map and the automatic switch distribution, re-modeling to calculate the automatic switch setting value and automatically issuing it to the equipment operation and maintenance unit; Step S6, at t1 after the line i, j loop operation is completed, based on the line first stage switch protection II segment setting value I II Check the steady-state current I on line i t1 ; wherein, if I t1 ≥ 80% I II , it is confirmed that the system is in a safe and stable operation state after loop closing; if I t1 < 80% I II , it is confirmed that the system is not in a safe and stable operation state after loop closing, and there is an overload trip risk; Step S7, in case I t1 <80% I II In case, at the time t2 after the completion of the closing operation, the steady-state current I II on the line is verified to be lower than the value I t2 ; Step S8, in I t2 <80% I II In the case, at the moment t3 after the completion of the loop operation, based on the line primary switch protection II segment setting value I II Check the steady-state current I on the line t3 ; if I t3 <80% I II , it is confirmed that there is always an overload trip risk after the loop. Step S9, in I t3 <80% I II In the case, the line operation mode is adjusted to reduce the risk of overload trip; the specific implementation of the step S9 of adjusting the line operation mode includes: Step S91, adjusting the line first-level switch II segment setting value, and increasing the line first-level switch II segment setting value by 5%; Or, Step S92, selecting a line k that is multi-connected with the line j to perform loop, wherein the loop process adopts the steps S1-S5; Step S93, selecting a removal point on the line between the lines i and j, and removing the line j, wherein the sectional switch corresponding to the removal point is located between the lines k and j.

2. The 10 kV urban distribution network closing operation method of claim 1, wherein, The step S2 comprises: Step S21, establishing an equivalent circuit containing the lines i and j according to the power grid topology, wherein the equivalent circuit is a distribution loop equivalent network obtained by equivalently reserving the 10kV bus and the feeder to the loop point part of the part above the 10kV bus; Step S22, calculating the loop closure steady state current Z S = R0+ jX0+ R i + jX i + R j + jX j In the formula: is the initial current of the open-loop feeder i, j; is the voltage value on both sides of the closing point; is the loop current caused by the closing point voltage after closing; R0, X0 are the equivalent impedance of the part above the 10kV bus; R i , X i are the equivalent resistance and reactance of the 10kV feeder i; R j , X j are the equivalent resistance and reactance of the 10kV feeder j; where: P i , Q i are the initial active power, initial reactive power of the 10 kV feeder i, P j , Q j are the initial active power, initial reactive power of the 10 kV feeder j, U N is the rated voltage of the 10 kV line U N = 10.5 kV, r is the resistance per unit length of the line, x is the reactance per unit length of the line, L i is the total length of the busbar of the substation to which the feeder i belongs to the closing point, L j is the total length of the busbar of the substation to which the feeder j belongs to the closing point; Step S23, the closing loop impact current I is calculated P : I P = k I1 In the formula, I1 is the steady-state current of the closed loop The effective value of k is 1.

62.

3. The 10 kV urban distribution network closing operation method according to claim 2, characterized in that, The preset scheme of each switch protection setting value in the step S3 comprises: The switch protection setting value comprises a current setting value and a time setting value, and the protection function is trip protection or sending an alarm message to an automatic system master station; In the switch protection setting value of the first-level switch, the current setting value is: the switch protection setting value of the transformer substation / the inverse coordination coefficient; and the time setting value is: the switch protection setting value of the transformer substation -△T, and△T is a time difference; In the switch protection setting value of the n-level sectional switch located behind the first-level switch, the current setting value is: the protection setting value of the n-1 sectional switch / the inverse coordination coefficient, n≥2, when n=2, the switch protection setting value of the first-level switch is calculated, and the inverse coordination coefficient is less than 1.5; and the time setting value is: the protection setting value of the n-1 sectional switch -△T, and△T is a time difference, when n=2, the switch protection setting value of the first-level switch is calculated; and the time difference is 0.1s-0.2s; The protection function of the first-level switch comprises trip protection and alarm; When the n sectional switch has a branch switch, the protection function of the n sectional switch comprises trip protection and alarm; When the n sectional switch does not have a branch switch, the protection function of the n sectional switch comprises alarm.

4. The 10 kV urban distribution network closing operation method of claim 3, wherein: The counter matching coefficient is 1.1, and the time level difference is 0.1s.

5. The 10kV urban distribution network closing loop operation method of claim 4, wherein: When the auxiliary discrimination condition that the phase angle difference on both sides of the closing loop point is less than 20 degrees is not met, the corresponding solution is to adjust the generator parameters; When the auxiliary discrimination condition that the voltage difference on both sides of the closing loop point is less than 20% is not met, the corresponding solution is to adjust the voltage of the upper-level substation; When the auxiliary discrimination condition that the closing loop impact current is less than the switch protection setting value is not met, the corresponding solution is to adjust the output of the power generation side and the line current; When the auxiliary discrimination condition that the closing loop steady-state current is less than the maximum load capacity of the line is not met, the corresponding solution is to adjust the output of the power generation side and the line current.

6. The 10 kV urban distribution network closing operation method of claim 1, wherein: Line primary switch protection II segment setting I II The overcurrent setting; t1 is the time when 30 minutes after the loop closing, t2 is the time when 60 minutes after the loop closing, and t3 is the time when 120 minutes after the loop closing.

7. The 10 kV urban distribution network closing operation method of claim 1, wherein, After the step S5 and before the step S6, the method further comprises a step S10 of issuing a pre-warning, prompting a failure reason, and generating a solution if the result of the step S3 is that the closing loop operation cannot be performed; the solution comprises adjusting the voltage of the upper-level substation, adjusting the output of the power generation side and the line current, and adjusting the generator parameters.

8. A 10 kV urban distribution network closing operation system, characterized in that, A computer program product for performing the method of any of claims 1-7.

9. An electronic device, comprising: Comprising: at least one processor; and a memory connected in communication with the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method of any of claims 1-7.

10. A non-transitory computer readable storage medium having stored thereon computer instructions, wherein, The computer instructions are used to enable the computer to perform the method of any of claims 1-7.

Images