Bus voltage-loss load transfer analysis method and system considering distributed power supply

Abstract

The invention discloses a bus voltage loss load transfer analysis method and system considering a distributed power supply, and the method comprises the steps: monitoring the inter-phase line voltage of a bus in real time, and dynamically analyzing whether the inter-phase line voltage value meets a judgment condition or not; according to the action signal of the main transformer low-voltage side switch or the mother branch switch associated with the bus, the current value and the protection action signal associated with the switch, the fault reason causing the bus voltage loss is judged; due to voltage loss caused by faults of the bus, power supply recovery is realized by adjusting a network topology structure through a hand-in-hand line; for a single-radiation line or a hand-in-hand line which fails to execute control, after fault isolation is completed between a bus and a superior power supply, the power supply of the hand-in-hand line is recovered by adjusting a network topology structure due to voltage loss caused by a superior fault of the bus; and power supply recovery is realized through the recovered hand-in-hand circuit or the circuit provided with the distributed power supply by adopting a bus inverse power supply mode. The bus voltage loss fault can be found in time, the load transfer strategy can be quickly given to realize power supply recovery, and the power supply quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution network research, and in particular to a method and system for analyzing busbar voltage loss load transfer in consideration of distributed power sources. Background Art

[0002] With the rapid development of social economy, the demand for electricity has shown a trend of continuous growth, and the grid structure has become more complex. At the same time, users' requirements for power quality and power supply reliability are constantly increasing, which has brought new challenges to the operation of power systems. In addition, with the advancement of renewable energy technology and policy support, the widespread application of distributed power sources (such as solar photovoltaic panels, wind turbines, etc.) has become one of the important directions for the development of power systems. The high penetration rate of distributed power sources has a profound impact on the design and operation of traditional distribution networks, especially in emergencies, such as substation busbar pressure failure. How to quickly sense the fault, accurately identify the fault type, and maximize power supply recovery through effective load transfer has become a key issue that needs to be solved urgently.

[0003] When dealing with busbar pressure loss faults, traditional power systems often rely on the dispatcher's experience and judgment to restore the normal operation of the power grid. This method may be effective when facing a simple power grid structure, but its limitations are becoming increasingly prominent as the scale of the power grid expands and the structure becomes more complex. It is difficult to make accurate decisions in a short period of time based on manual experience alone, especially considering the existence of distributed power sources, which makes the fault identification and recovery process more complicated. Therefore, developing a busbar pressure loss load transfer analysis method that can take into account the access of distributed power sources is of great significance to improving the emergency response capability and power supply restoration efficiency of the power system. Summary of the invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a busbar pressure loss load transfer analysis method and system considering distributed power sources, which can quickly sense sudden substation busbar pressure loss faults, accurately identify fault types, and maximize power supply recovery through load transfer under the background of complex power grid structure and high penetration distributed power sources.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In the first aspect, the present invention provides a method for analyzing load transfer when a busbar loses voltage considering distributed power sources, comprising: based on the distribution automation master station system, real-time monitoring of the three phase-to-phase line voltages of the busbar is performed, and dynamically analyzing whether the values ​​of the three phase-to-phase line voltages meet a first judgment condition; if the first judgment condition is met, the fault cause causing the busbar voltage loss is determined according to the action signal of the low-voltage side switch of the main transformer or the bus branch switch associated with the busbar, the current value and the protection action signal associated with the switch; if the voltage loss is caused by a fault in the busbar itself, power supply is restored to the hand-in-hand line by adjusting the network topology structure; if the voltage loss is caused by a fault in the upper part of the busbar, power supply is restored to the hand-in-hand line by adjusting the network topology structure, and after the fault isolation between the busbar and the upper power source is completed for the single radial line or the hand-in-hand line that fails to execute control, the restored hand-in-hand line or the line with distributed power sources is used to reverse power to the busbar to achieve full power recovery or partial power recovery according to the feeder priority.

[0008] As a preferred solution of the method for analyzing the load transfer in the case of busbar voltage loss considering distributed power sources described in the present invention, the power supply recovery of the hand-in-hand line by adjusting the network topology structure includes:

[0009] Based on the topology service of the distribution automation master station system, all transfer path sets of the hand-in-hand lines associated with the bus are obtained;

[0010] Conduct a multi-dimensional analysis of all the transfer paths, including the load rate of the opposite feeder after the transfer, the load rate of the opposite main transformer after the transfer, the controllability of the transfer operation switch, whether there is a risk of power loss for important users after the transfer, and whether the transfer path is listed;

[0011] An optimal solution for adjusting the network topology is formed according to the result of the multi-dimensional analysis, and power supply restoration is achieved through the optimal solution for adjusting the network topology.

[0012] As a preferred solution of the busbar pressure loss load transfer analysis method considering distributed power sources described in the present invention, it is checked whether the transformer lowering switch and the busbar branch switch are in the closed position. If they are in the closed position, the transformer lowering switch is controlled to perform an opening operation to complete the isolation of the busbar from the upper power supply fault.

[0013] As a preferred solution of the busbar pressure loss load transfer analysis method considering distributed power sources described in the present invention, wherein: the method of backfeeding the busbar through the restored hand-in-hand line or the line with distributed power sources installed adopts the method of backfeeding the busbar to achieve full power supply recovery or partial power supply recovery according to the feeder priority, wherein the selection of the backfeed channel includes:

[0014] From the hand-in-hand lines that achieve power restoration by adjusting the network topology, select the line with the largest remaining capacity margin on the opposite side after power transfer and record it as F1;

[0015] If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the power transfer exceeds the total capacity of all unrestored power supply lines, line F1 is selected as the reverse transmission channel;

[0016] If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the transfer does not exceed the total capacity of all unrestored power supply lines, then find out whether there is a line under the bus with a distributed power source installed. If there is and the capacity of the distributed power source is greater than the total capacity of all unrestored power supply lines, then select the line with the distributed power source installed as the reverse transmission channel;

[0017] If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the transfer and the margin of the line with distributed power sources installed are unable to supply power to all unrestored lines, the line with the larger margin among the two is selected as the reverse transmission channel.

[0018] As a preferred solution of the load transfer analysis method for busbar pressure loss considering distributed power sources described in the present invention, wherein: the method of backfeeding power to the busbar through the restored hand-in-hand line or the line with distributed power sources installed to achieve full power supply recovery or partial power supply recovery according to feeder priority includes:

[0019] For the hand-in-hand lines that have failed to execute control, the lines that have failed to execute line exit switch control are included in the set of lines that must be reversed, and the remaining lines are given the results of load shedding or reversed strategies one by one according to the line power supply recovery priority and the available margin of the reversed channel;

[0020] Calculate the total capacity value of all lines in the set of lines that must be reversed. If the total capacity value is greater than the available margin of the reverse channel, terminate the reverse strategy analysis. Otherwise, compare the required line capacity with the remaining available margin of the reverse channel according to the line power supply recovery priority.

[0021] If the remaining available margin of the reverse transmission channel is greater than the required transfer capacity of the line, the line strategy is reverse transmission, otherwise the strategy is load shedding. If the reverse transmission strategy of the previous line is reverse transmission, the remaining available margin of the reverse transmission channel needs to be updated;

[0022] Repeat the above determination steps and give the reverse transmission strategies for all lines one by one.

[0023] As a preferred solution of the method for analyzing the load transfer in the case of bus voltage loss considering distributed power sources described in the present invention, the line power supply restoration priority includes:

[0024] If the load rate of the opposite feeder is low after the power transfer, the priority of power supply restoration of the line is high;

[0025] If the load rate of the main transformer on the opposite side is low after the power transfer, the priority level of line power supply restoration is high;

[0026] If the transfer operation switch is a remotely controlled automated device, the priority of line power restoration is high;

[0027] If there is no risk of important users losing power after the power transfer, the priority of line power restoration is high;

[0028] If there is no prohibited operation sign on the transfer path, the priority of line power supply restoration is high.

[0029] As a preferred solution of the busbar pressure loss load transfer analysis method considering distributed power sources described in the present invention, the load rate of the opposite feeder after the transfer β lafter The calculation is:

[0030]

[0031] Among them, I load1 ,I load2 are the current value or historical sampling value of the line to be transferred on this side and the current current value of the line on the opposite side, I load2max is the upper limit of the opposite side current;

[0032] Load factor of the opposite main transformer after power transfer β wafter The calculation is:

[0033]

[0034] Among them, I winding1 ,I winding2 are the current value or historical sampling value of the line to be transferred on this side and the current current value of the low-voltage side of the main transformer winding on the opposite side, I winding2max It is the upper limit of the current on the low-voltage side of the opposite main transformer winding.

[0035] In a second aspect, the present invention provides a busbar voltage loss load transfer analysis system considering distributed power sources, comprising:

[0036] A first determination unit is used to monitor the three phase-to-phase line voltages of the busbar in real time based on the distribution automation master station system, and dynamically analyze whether the values ​​of the three phase-to-phase line voltages meet the first determination condition;

[0037] The second determination unit is used to determine the fault cause of busbar voltage loss according to the action signal of the main transformer low-voltage side switch or busbar branch switch associated with the busbar, the current value and the protection action signal associated with the switch if the first determination condition is met;

[0038] The first operating unit is used to restore power supply to the hand-in-hand line by adjusting the network topology structure if the voltage loss is caused by a bus failure itself;

[0039] The second operating unit is used to restore power supply to the hand-in-hand lines by adjusting the network topology structure if the voltage loss is caused by a busbar upstream fault. For single radial lines or hand-in-hand lines that fail to execute control, after the busbar and the upstream power supply are isolated from the fault, the restored hand-in-hand lines or lines with distributed power sources are used to reverse power to the busbar, thereby restoring all power supply or partially restoring power supply according to feeder priority.

[0040] In a third aspect, the present invention provides a computing device, comprising:

[0041] Memory and processor;

[0042] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the load transfer analysis method considering bus voltage loss of distributed power sources are implemented.

[0043] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for analyzing load transfer in the event of bus voltage loss taking into account distributed power sources.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a busbar pressure loss load transfer analysis method and system taking into account the access of distributed power sources, which can timely sense the busbar pressure loss fault and identify the fault type (non-busbar fault and busbar fault) according to the switch action signal and the protection action signal, and quickly provide a fault handling plan and a load transfer plan, so as to maximize the rapid restoration of power, improve the power supply quality, and reduce economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0046] Figure 1 A schematic diagram of the overall process logic of a method for analyzing load transfer in consideration of busbar voltage loss of distributed power sources according to an embodiment of the present invention;

[0047] Figure 2 A schematic diagram of a judgment flow of a method for analyzing load transfer in consideration of busbar voltage loss of distributed power sources according to an embodiment of the present invention;

[0048] Figure 3 A flow chart of busbar pressure loss and identification of the cause of busbar pressure loss in a method for analyzing load transfer in which a distributed power source is considered in an embodiment of the present invention;

[0049] Figure 4 A flow chart of generating a non-bus fault bus reverse transmission channel of a bus voltage loss load transfer analysis method considering distributed power sources according to an embodiment of the present invention;

[0050] Figure 5 A flow chart of generating a bus reverse transmission line strategy for a non-bus fault bus according to a bus voltage loss load transfer analysis method considering distributed power sources according to an embodiment of the present invention;

[0051] Figure 6 A schematic diagram of the contents of a power outage bus list of a method for analyzing load transfer in the event of bus voltage loss considering distributed power sources according to an embodiment of the present invention;

[0052] Figure 7 A schematic diagram of fault analysis content of a method for analyzing load transfer in consideration of busbar voltage loss of distributed power sources according to an embodiment of the present invention;

[0053] Figure 8 A schematic diagram of the transfer opposite side content of a load transfer analysis method considering busbar voltage loss of distributed power sources according to an embodiment of the present invention;

[0054] Fig. 9 A schematic diagram of the reverse transfer content of the load transfer analysis method considering busbar voltage loss of distributed power sources described in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0056] Example 1

[0057] Reference Figure 1-Figure 5 As an embodiment of the present invention, a method for analyzing load transfer when busbar voltage loss is considered for distributed power sources is provided, which can timely sense busbar voltage loss, accurately identify the type of fault that causes busbar voltage loss, and maximize power supply recovery by means of load transfer, thereby improving power supply reliability and safety. Figure 1 The specific steps shown include:

[0058] S100: Based on the real-time monitoring of the three phase-to-phase line voltages of the busbar by the distribution automation master station system, dynamically analyzing whether the values ​​of the three phase-to-phase line voltages meet the first determination condition;

[0059] S200: If the first determination condition is met, the fault cause causing the busbar voltage loss is determined according to the action signal of the low-voltage side switch of the main transformer or the busbar branch switch associated with the busbar, the current value and the protection action signal associated with the switch;

[0060] S300: If the voltage loss is caused by a bus fault, the hand-in-hand line is restored to power by adjusting the network topology;

[0061] S400: If the voltage loss is caused by a fault at the upper level of the bus, the hand-in-hand line is restored by adjusting the network topology. For single radial lines or hand-in-hand lines with failed execution control, after the bus and the upper power supply are isolated, the restored hand-in-hand line or the line with distributed power supply is used to reverse the power supply to the bus to restore all power or partially restore power according to the feeder priority.

[0062] It should be noted that the present invention provides a busbar pressure loss load transfer analysis method and system taking into account the access of distributed power sources. The method can timely sense the busbar pressure loss fault and identify the fault type (non-busbar fault and busbar fault) according to the switch action signal and the protection action signal, and quickly provide a fault handling plan and a load transfer plan to maximize the rapid restoration of power, improve the power supply quality, and reduce economic losses.

[0063] In the embodiment of the present application, the above step S100 includes the following sub-steps A1-A2;

[0064] In A1: Based on the real-time monitoring of the three phase-to-phase line voltages of the busbar by the distribution automation master station system, the three phase-to-phase line voltages of the 10kV / 20kV busbar are: the voltage U between phases A and B AB , the voltage U between phases B and C BC And the voltage U between phases C and A CA ;

[0065] In A2: dynamically analyzing whether the values ​​of the three phase-to-phase line voltages meet the first determination condition;

[0066] In an optional embodiment, the first judgment condition is that the voltage jumps and is lower than the threshold, where the jump refers to a sudden change in voltage from a normal value to an abnormal value. For example, for a 10kV bus, the normal value range is 9kV to 12kV, and the threshold is 0.05kV. The system can be flexibly configured. When the three phase-to-phase line voltages of a bus all jump from normal values ​​to abnormal values ​​and the values ​​are lower than the threshold, the bus can be listed as a suspected voltage-loss bus.

[0067] In the embodiment of the present application, the above step S200 includes the following sub-steps B1-B2;

[0068] In B1: Figure 2 As shown, if the first determination condition is met, that is, the voltage jumps and is lower than the threshold, the fault cause causing the busbar voltage loss is further determined;

[0069] In B2: according to the action signal of the low-voltage side switch of the main transformer or the busbar branch switch associated with the busbar, the current value and the protection action signal associated with the switch, the fault cause causing the busbar pressure loss is determined;

[0070] Specifically, the protection actions include main transformer low backup protection, busbar protection action, and main transformer protection action;

[0071] Specifically, the fault causes that cause busbar voltage loss include busbar fault itself (busbar fault) and busbar upper main transformer fault (non-busbar fault).

[0072] In an optional embodiment, if Figure 3 As shown, the main transformer low-voltage side circuit breaker and busbar branch switch associated with the bus are obtained through topological search, and the protection action signals, measurement values ​​and position signals corresponding to the two types of switches are obtained. If the delay is within 30 seconds, the transformer low-voltage switch trips + the main transformer low-voltage backup protection action or the busbar branch protection action or the main transformer protection action + the transformer low-voltage switch trips (or does not trip and remains in the open state) + the busbar branch trips, it can be determined that a busbar fault is suspected to have occurred; if the voltage loss duration reaches the set value, the transformer low-voltage switch current jumps and is lower than the threshold + there is no transformer low-voltage tripping + busbar branch tripping + no main transformer low-voltage backup protection action + no main transformer protection action, it can be determined as a suspected non-busbar fault.

[0073] In the embodiment of the present application, the above step S300 includes the following sub-steps C1-C3;

[0074] In C1: Based on the topology service of the distribution automation master station system, obtain the set of all transfer paths of the hand-in-hand line associated with the busbar;

[0075] In C2: Perform multi-dimensional analysis on all transfer paths, including the load rate of the opposite feeder after the transfer, the load rate of the opposite main transformer after the transfer, the controllability of the transfer operation switch, whether there is a risk of power loss for important users after the transfer, and whether the transfer path is listed.

[0076] In C3: an optimal solution for adjusting the network topology is formed based on the results of the multi-dimensional analysis, and power supply restoration is achieved through the optimal solution for adjusting the network topology;

[0077] In the embodiment of the present application, the above step S400 includes the following sub-steps D1-D3;

[0078] In D1: forming a final solution set for adjusting the network topology structure according to step S300;

[0079] In D2: Check whether the busbar has completed fault isolation from the upper power supply;

[0080] In D3: Select the line (reverse transmission channel) that reverses power to the bus from the hand-in-hand lines that have completed power restoration or from the lines with distributed power sources installed, so as to achieve full power restoration through bus reverse transmission for single radial lines or lines where hand-in-hand execution control fails, or achieve partial power restoration according to the power restoration priority;

[0081] In an optional embodiment, the step of checking whether the busbar has completed fault isolation from the upper power supply is: checking whether the transformer lowering switch and the bus splitter are in the closed position; if so, controlling the transformer lowering switch to perform a split operation to complete the fault isolation between the busbar and the upper power supply.

[0082] In an optional embodiment, if Figure 4 As shown, the options for the reverse channel include:

[0083] From the hand-in-hand lines that achieve power restoration by adjusting the network topology, select the line with the largest remaining capacity margin on the opposite side after power transfer and record it as F1;

[0084] If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the power transfer exceeds the total capacity of all unrestored power supply lines, line F1 will be selected as the reverse transmission channel;

[0085] If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the transfer does not exceed the total capacity of all power supply lines that have not been restored, then find out whether there is a line under the bus with a distributed power source installed. If there is and the capacity of the distributed power source is greater than the total capacity of all power supply lines that have not been restored, then select the line with the distributed power source installed as the reverse transmission channel;

[0086] If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the transfer and the margin of the line with the distributed generation installed cannot supply power to all the unrestored lines, the line with the larger margin between the two will be selected as the reverse transmission channel;

[0087] It should be noted that the available margin of the opposite line = min (line channel limit on this side, line channel limit on the opposite side) - (load of the outgoing line switch on the opposite side + load of the outgoing line switch on this side);

[0088] In an optional embodiment, if Figure 5As shown, for a single radial line or a hand-in-hand line that fails to execute control, if the hand-in-hand line that fails to execute control fails to execute the line outlet switch control, it is included in the set of lines that must be reversed, and the remaining lines are given the results of load shedding or reversed strategies one by one according to the line power supply recovery priority and the available margin of the reverse channel, among which the line power supply recovery priority can be flexibly configured;

[0089] Specifically, the calculation of the available margin of the reverse channel is:

[0090] I remained =I 2max -I2-I1

[0091] Among them, I remained is the remaining acceptable load of the reverse channel line 2, I 2max is the maximum load of the reverse channel line 2, I2 is the current load of the reverse channel line 2, and I1 is the load that has been transferred to the reverse channel line 2.

[0092] Specifically, the steps of the reverse delivery strategy analysis include:

[0093] Calculate the total capacity of all lines in the set of lines that must be reversed. If the total capacity is greater than the available margin of the reverse channel, terminate the reverse strategy analysis. Otherwise, compare the required line capacity with the remaining available margin of the reverse channel according to the line power supply restoration priority.

[0094] If the remaining available margin of the reverse transmission channel is greater than the required transfer capacity of the line, the line strategy is reverse transmission, otherwise the strategy is load shedding. If the reverse transmission strategy of the previous line is reverse transmission, the remaining available margin of the reverse transmission channel needs to be updated;

[0095] Repeat the above determination steps and give the reverse transmission strategies for all lines one by one.

[0096] In an optional embodiment, the line power restoration priority includes:

[0097] ① If the load rate of the opposite feeder is low after the power transfer, the priority level of line power supply restoration is high;

[0098] ② If the load rate of the main transformer on the opposite side is low after the power transfer, the priority level of line power supply restoration is high;

[0099] ③ If the power transfer operation switch is an automated device that can be remotely controlled, the priority level of line power supply restoration is high;

[0100] ④ If there is no risk of important users losing power after the power supply is transferred, the priority of line power supply restoration is high;

[0101] ⑤ If there is no prohibited operation sign on the transfer path, the priority level of line power supply restoration is high.

[0102] Specifically, the load rate of the opposite feeder after the transfer is β lafter The calculation is:

[0103]

[0104] Among them, I load1 ,I load2 are the current value or historical sampling value of the line to be transferred on this side and the current current value of the line on the opposite side, I load2max is the upper limit of the opposite side current;

[0105] Specifically, after the transfer, the load factor of the opposite main transformer β wafter The calculation is:

[0106]

[0107] Among them, I winding1 ,I winding2 are the current value or historical sampling value of the line to be transferred on this side and the current current value of the low-voltage side of the main transformer winding on the opposite side, I winding2max It is the upper limit of the current on the low-voltage side of the opposite main transformer winding.

[0108] Specifically, the risk of power loss for important users, where the important user system can be flexibly set, the risk of power loss is determined by comparing the power supply before and after the re-supply for important users. If the power supply amount is reduced after the re-supply, it is judged that there is a risk of power loss, otherwise, there is no risk of power loss.

[0109] It should be noted that in order to restore power supply as much as possible, for non-bus faults, the single power supply line or the line that the contact switch cannot remotely control can be restored through bus reverse transmission to achieve full power supply restoration or partial power supply restoration according to the feeder priority. First, the line with multiple potential power supply points is transferred; then check whether the low-voltage side switch of the main transformer and the bus switch are in the open position. If they are still in the closed position, the above switches are first controlled to be open to isolate them from the upper fault; secondly, the reverse transmission channel is selected from the lines that have completed the transfer or the distributed power supply; again, the reverse transmission and load shedding strategies are given according to the power supply restoration order from the lines that need to be restored through the reverse transmission channel; finally, the load shedding operation is performed first, the outgoing line switch of the corresponding line is controlled to be open, and then the outgoing line switch of the reverse transmission channel is closed to achieve power supply restoration.

[0110] The above is a schematic scheme of a method for analyzing the load transfer of a busbar undervoltage of a distributed power source in this embodiment. It should be noted that the technical scheme of the system for analyzing the load transfer of a busbar undervoltage of a distributed power source and the technical scheme of the method for analyzing the load transfer of a busbar undervoltage of a distributed power source mentioned above belong to the same concept. The details not described in detail in the technical scheme of the system for analyzing the load transfer of a busbar undervoltage of a distributed power source in this embodiment can be referred to the description of the technical scheme of the method for analyzing the load transfer of a busbar undervoltage of a distributed power source mentioned above.

[0111] This embodiment also provides a busbar voltage loss load transfer analysis system considering distributed power sources, including:

[0112] A first determination unit is used to monitor the three phase-to-phase line voltages of the busbar in real time based on the distribution automation master station system, and dynamically analyze whether the values ​​of the three phase-to-phase line voltages meet the first determination condition;

[0113] The second determination unit is used to determine the fault cause of busbar voltage loss according to the action signal of the main transformer low-voltage side switch or busbar branch switch associated with the busbar, the current value and the protection action signal associated with the switch if the first determination condition is met;

[0114] The first operating unit is used to restore power supply to the hand-in-hand line by adjusting the network topology structure if the voltage loss is caused by a bus failure itself;

[0115] The second operating unit is used to restore power supply to the hand-in-hand lines by adjusting the network topology structure if the voltage loss is caused by a busbar upstream fault. For single radial lines or hand-in-hand lines that fail to execute control, after the busbar and the upstream power supply are isolated from the fault, the restored hand-in-hand lines or lines with distributed power sources are used to reverse power to the busbar, thereby restoring all power supply or partially restoring power supply according to feeder priority.

[0116] The above-mentioned unit modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above-mentioned modules.

[0117] This embodiment also provides a computing device, which includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a busbar pressure loss load transfer analysis method considering distributed power sources is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a button, trackball or touchpad set on the housing of the computer device, or an external keyboard, touchpad or mouse.

[0118] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method proposed in the above embodiment is implemented.

[0119] The storage medium proposed in this embodiment and the method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0120] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0121] Example 2

[0122] Reference Figure 6 to Figure 9 Based on the previous embodiment, this embodiment provides an application example of a method and system for analyzing load transfer under bus voltage loss considering distributed power sources, in order to verify and illustrate the technical effects adopted in this method.

[0123] This embodiment takes a 10kV busbar voltage loss fault as an example. First, the three phase-to-phase line voltages of the busbar are monitored in real time based on the distribution automation master station system. The values ​​of the three phase-to-phase line voltages are dynamically analyzed to see whether they meet the first judgment condition, that is, the voltage jumps and is lower than the threshold value. Figure 6 As shown in the power outage bus list, the system detected that the bus voltage value jumped to 0;

[0124] The system detects that the bus voltage value jumps to 0, which meets the first judgment condition. Combined with the fact that the current value of the low-voltage side switch of the main transformer jumps to 0, the low-voltage backup protection of the main transformer does not operate, and the low-voltage switch of the main transformer does not trip, it is determined that a non-bus fault occurs on the 10kV bus, such as Figure 7 The fault analysis content is shown below;

[0125] like Figure 8 As shown in the figure, based on the topology service of the distribution automation master station system, the 7 hand-in-hand lines associated with the busbar are transferred to the opposite line through the tie switch. According to the remote control execution of the switch, 3 of them, XX line, YY line, and WW line, cannot be remotely controlled; Fig. 9 As shown in the figure, one line is selected from the lines that have successfully transferred power hand in hand as the reverse transmission channel, and the three lines that cannot be remotely controlled and the single radial line are determined according to the reverse transmission strategy calculation principle to realize power supply restoration through reverse transmission and the line that must shed load;

[0126] Therefore, it can be seen from the above steps that the present invention provides a busbar pressure loss load transfer analysis method and system considering the access of distributed power sources, which can timely sense the busbar pressure loss fault and identify the fault type (non-busbar fault and busbar fault) according to the switch action signal and the protection action signal, and quickly provide a fault handling plan and a load transfer plan to achieve maximum rapid power restoration, improve power supply quality, and reduce economic losses.

[0127] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0128] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt 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.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0129] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0130] 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.

[0131] 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.

[0132] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0133] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for analyzing load transfer when busbar voltage is lost considering distributed power sources, characterized in that: include: Based on the real-time monitoring of the three phase-to-phase line voltages of the busbar by the distribution automation master station system, dynamically analyzing whether the values ​​of the three phase-to-phase line voltages meet the first determination condition; If the first determination condition is met, the fault cause causing the busbar voltage loss is determined according to the action signal of the low-voltage side switch of the main transformer or the busbar branch switch associated with the busbar, the current value and the protection action signal associated with the switch; If the voltage loss is caused by a busbar fault, the hand-in-hand line can be restored by adjusting the network topology; If the voltage loss is caused by a fault at the upper level of the bus, power supply will be restored by adjusting the network topology for the hand-in-hand lines. After the bus and the upper power supply are isolated from the fault of the single radial line or the hand-in-hand line with failed execution control, the restored hand-in-hand line or the line with distributed power supply will be used to reverse the power supply to the bus to achieve full power restoration or partial power restoration according to the feeder priority.

2. The method for analyzing load transfer in case of busbar voltage loss considering distributed power sources according to claim 1, characterized in that: The hand-in-hand line is restored to power supply by adjusting the network topology structure, including: Based on the topology service of the distribution automation master station system, all transfer path sets of the hand-in-hand lines associated with the bus are obtained; Conduct a multi-dimensional analysis of all the transfer paths, including the load rate of the opposite feeder after the transfer, the load rate of the opposite main transformer after the transfer, the controllability of the transfer operation switch, whether there is a risk of power loss for important users after the transfer, and whether the transfer path is listed; An optimal solution for adjusting the network topology is formed according to the result of the multi-dimensional analysis, and power supply restoration is achieved through the optimal solution for adjusting the network topology.

3. The method for analyzing load transfer in case of busbar voltage loss considering distributed power sources according to claim 2, characterized in that: Check whether the transformer lowering switch and the busbar switch are in the closed position. If they are in the closed position, control the transformer lowering switch to perform the opening operation to complete the isolation of the busbar from the upper power supply fault.

4. The method for analyzing load transfer in case of busbar voltage loss considering distributed power sources according to claim 3, characterized in that: The method of backfeeding the busbar through the restored hand-in-hand line or the line with distributed power supply is used to achieve full power supply restoration or partial power supply restoration according to the feeder priority, wherein the selection of the backfeed channel includes: From the hand-in-hand lines that achieve power restoration by adjusting the network topology, select the line with the largest remaining capacity margin on the opposite side after power transfer and record it as F1; If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the power transfer exceeds the total capacity of all unrestored power supply lines, line F1 is selected as the reverse transmission channel; If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the transfer does not exceed the total capacity of all unrestored power supply lines, then find out whether there is a line under the bus with a distributed power source installed. If there is and the capacity of the distributed power source is greater than the total capacity of all unrestored power supply lines, then select the line with the distributed power source installed as the reverse transmission channel; If the remaining margin of line F1 with the largest remaining capacity margin on the opposite side after the transfer and the margin of the line with distributed power sources installed are unable to supply power to all unrestored lines, the line with the larger margin among the two is selected as the reverse transmission channel.

5. The load transfer analysis method considering busbar voltage loss of distributed power sources according to claim 4 is characterized in that: The method of using the restored hand-in-hand line or the line with distributed power supply to feed power back to the busbar to achieve full power restoration or partial power restoration according to feeder priority includes: For the hand-in-hand lines that have failed to execute control, the lines that have failed to execute line exit switch control are included in the set of lines that must be reversed, and the remaining lines are given the results of load shedding or reversed strategies one by one according to the line power supply recovery priority and the available margin of the reversed channel; Calculate the total capacity value of all lines in the set of lines that must be reversed. If the total capacity value is greater than the available margin of the reverse channel, terminate the reverse strategy analysis. Otherwise, compare the required line capacity with the remaining available margin of the reverse channel according to the line power supply recovery priority. If the remaining available margin of the reverse transmission channel is greater than the required transfer capacity of the line, the line strategy is reverse transmission, otherwise the strategy is load shedding. If the reverse transmission strategy of the previous line is reverse transmission, the remaining available margin of the reverse transmission channel needs to be updated; Repeat the above determination steps and give the reverse transmission strategies for all lines one by one.

6. The load transfer analysis method considering busbar voltage loss of distributed power sources according to claim 5 is characterized in that: The line power restoration priorities include: If the load rate of the opposite feeder is low after the power transfer, the priority of power supply restoration of the line is high; If the load rate of the main transformer on the opposite side is low after the power transfer, the priority level of line power supply restoration is high; If the transfer operation switch is a remotely controlled automated device, the priority of line power restoration is high; If there is no risk of important users losing power after the power transfer, the priority of line power restoration is high; If there is no prohibited operation sign on the transfer path, the priority of line power supply restoration is high.

7. The load transfer analysis method considering bus voltage loss of distributed power sources according to claim 6 is characterized in that: Load rate of opposite feeder after power transfer β lafter The calculation is: Among them, I load1 ,I load2 are the current value or historical sampling value of the line to be transferred on this side and the current current value of the line on the opposite side, I load2max is the upper limit of the opposite side current; Load factor of the opposite main transformer after power transfer β wafter The calculation is: Among them, I winding1 ,I winding2 are the current value or historical sampling value of the line to be transferred on this side and the current current value of the low-voltage side of the main transformer winding on the opposite side, I winding2max It is the upper limit of the current on the low-voltage side of the opposite main transformer winding.

8. A system using the method for analyzing load transfer in consideration of busbar voltage loss of distributed power sources as claimed in any one of claims 1 to 7, characterized in that: include: A first determination unit is used to monitor the three phase-to-phase line voltages of the busbar in real time based on the distribution automation master station system, and dynamically analyze whether the values ​​of the three phase-to-phase line voltages meet the first determination condition; The second determination unit is used to determine the fault cause of busbar voltage loss according to the action signal of the main transformer low-voltage side switch or busbar branch switch associated with the busbar, the current value and the protection action signal associated with the switch if the first determination condition is met; The first operating unit is used to restore power supply to the hand-in-hand line by adjusting the network topology structure if the voltage loss is caused by a bus failure itself; The second operating unit is used to restore power supply to the hand-in-hand lines by adjusting the network topology structure if the voltage loss is caused by a busbar upstream fault. For single radial lines or hand-in-hand lines that fail to execute control, after the busbar and the upstream power supply are isolated from the fault, the restored hand-in-hand lines or lines with distributed power sources are used to reverse power to the busbar, thereby restoring all power supply or partially restoring power supply according to feeder priority.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions, when executed by a processor, implement the steps of the method according to any one of claims 1 to 7.

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