A method and system for detecting power outage in a power grid

Abstract

The invention discloses a power grid power outage detection method and system, belonging to the technical field of power grid power outage detection. The method comprises the following steps: obtaining a circuit structure diagram of a power grid and operation data of a plurality of lightning arresters collected by a lightning arrester monitoring terminal / arrester monitoring device in the power grid; if the lightning arrester is not deteriorated / damaged, filtering out abnormal data in the operation data based on a preset first screening rule; filtering out abnormal data caused by a lightning strike event or an overvoltage event based on a preset second screening rule and marking the abnormal data; and drawing a power outage area distribution map of the power grid based on the circuit structure diagram according to the abnormal data; the invention uses a lightning arrester to perform power outage detection, which is fast and accurate, introduces the judgment of whether the lightning arrester is damaged and the lightning strike / overvoltage event, and quickly judges the cause of the power outage. Since different power supply sources are used and the lightning arresters are arranged at various nodes of the power grid and are located at different positions, the requirements of "non-homologous source" and "double confirmation" are met.

Description

Technical Field

[0001] The invention relates to a power grid power outage detection method and system, belonging to the technical field of power grid power outage detection. Background Art

[0002] Electric energy refers to the ability to use electricity to do work in various forms. It is not only an economical, practical, clean, easy to control and convert energy form, but also a special product provided by the power department to power users with quality guaranteed by the three parties of power generation, supply and use. Electric energy is the driving force for the normal operation of the national economy and is related to all areas of cities and villages. The stable operation of power grid equipment is also one of the main assessment indicators of the power supply department. Power outages can be divided into planned outages and unplanned outages. Planned power outages are generally notified to relevant departments in advance, and users have made preparations for power outages. In order to avoid affecting other users, the power outage lines will be separated from the normally operating power grid, and other users of the power grid will use electricity normally. Unplanned power outages are generally unknown in advance and are affected by various external sudden factors (such as lightning strikes, overvoltage, environmental factors, cable failures, etc.), causing the production and work of the majority of users to be unable to operate normally, and the power supply department will also suffer huge economic losses.

[0003] The prior art classifies the causes of unplanned power outages. According to the classification results, the cause of line power outages due to lightning strikes ranks first among power outages in power supply circuits. In order to reduce the damage to the power grid caused by lightning strikes or overvoltage, the power supply department installs lightning arresters on the lines. However, there are many reasons for unplanned power outages, and the power grid system is very complicated, so it is impossible to timely and accurately determine the cause of the power grid power outage. If the scope of the power outage cannot be accurately determined in a timely manner, it is impossible to find the fault point as soon as possible, eliminate the fault in time, and restore power supply. This is a difficult problem in the research of prior art. In order to detect power outages in a timely and accurate manner, the power supply department has also put forward the requirements of "non-same source" and "double confirmation". Non-same source: that is, confirmation through different devices; double confirmation: that is, confirmation through at least two or more devices. Summary of the invention

[0004] The purpose of the present invention is to provide a power grid power outage detection method and system to solve the problem in the prior art that the power outage scope cannot be accurately and quickly determined, and to meet the requirements of "non-homogeneous source" and "double confirmation".

[0005] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a method for detecting a power outage in a power grid, comprising:

[0007] Obtaining a circuit structure diagram of the power grid and operation data of multiple lightning arresters collected by a lightning arrester monitoring terminal / arrester monitoring device in the power grid;

[0008] If the arrester is not degraded / damaged, filtering out abnormal data in the operation data based on a preset first screening rule;

[0009] Based on the preset second screening rule, abnormal data caused by lightning strike events or overvoltage events are screened out and marked;

[0010] A power grid blackout area distribution map is drawn based on the circuit structure diagram according to all abnormal data.

[0011] Furthermore, the operation data of the lightning arrester includes the total leakage current, resistive current, lightning strike event occurrence time and overvoltage event occurrence time of the lightning arrester.

[0012] Furthermore, the step of determining whether the arrester is degraded / damaged includes:

[0013] If the total leakage current of the arrester changes by more than 5%, and the resistive current of the arrester changes by more than 50%, the arrester is degraded;

[0014] If the total leakage current of the arrester changes by more than 10% and the resistive current of the arrester changes by more than 50%, the arrester is damaged.

[0015] Further, filtering out abnormal data in the operation data based on a preset first filtering rule includes:

[0016] If the total leakage current of a lightning arrester is 0, the data is abnormal data.

[0017] Furthermore, the method of screening out abnormal data caused by lightning strike events or overvoltage events and marking them based on the preset second screening rule includes:

[0018] The generation time of the abnormal data is compared with the occurrence time of the lightning strike event and the occurrence time of the overvoltage event. If the two compared times are the same, the abnormal data is abnormal data caused by the lightning strike event or the overvoltage event, and it is marked. If the abnormal data is caused by the lightning strike event, it is marked as lightning strike abnormal data, and if the abnormal data is caused by the overvoltage event, it is marked as overvoltage abnormal data.

[0019] Furthermore, the method of drawing a power outage area distribution map of the power grid based on the circuit structure diagram according to all abnormal data includes:

[0020] If the abnormal data comes from the arrester on the high-voltage transmission line, the main grid substation connected to the high-voltage transmission line in the circuit structure diagram and the high-voltage distribution lines under the secondary bus of the connected main power transformer are all marked as power outage areas, and the low-voltage transformer under the high-voltage distribution line in the circuit structure diagram and its subordinate low-voltage lines are also all marked as power outage areas;

[0021] If the abnormal data comes from the lightning arrester on a high-voltage distribution line under the secondary busbar of the main transformer in the main grid substation, the distribution transformer connected to the high-voltage distribution line and its subordinate low-voltage distribution lines in the circuit structure diagram shall all be marked as power outage areas;

[0022] If the abnormal data comes from the arrester on a low-voltage distribution line under the secondary bus of the distribution transformer, all users connected to this low-voltage distribution line in the circuit structure diagram will be marked as power outage areas;

[0023] In addition, when a certain area is marked as a power outage area, the corresponding abnormal data label is marked on the power outage area, specifically including: if the abnormal data is lightning strike abnormal data, the corresponding power outage area is marked as a lightning strike power outage area; if the abnormal data is overvoltage abnormal data, the corresponding power outage area is marked as an overvoltage power outage area.

[0024] Furthermore, after obtaining the power grid power outage area distribution map, the method further includes sending an emergency instruction according to the power outage information included in the power grid power outage area distribution map, wherein sending an emergency instruction according to the power outage information included in the power grid power outage area distribution map includes:

[0025] If there is a lightning blackout area marked in the power grid blackout area distribution map, a closing command is sent to the power grid maintenance department corresponding to the lightning blackout area;

[0026] If the power outage area distribution map of the power grid has a power outage area other than the lightning power outage area marked, a maintenance instruction is sent to the power grid maintenance department corresponding to the power outage area.

[0027] In a second aspect, the present invention provides a power grid power outage detection system, comprising a lightning arrester monitoring cloud platform, a plurality of lightning arrester monitoring terminals, a plurality of lightning arrester monitoring devices, a plurality of lightning arresters, a main network aggregation node and a distribution network aggregation node, wherein the lightning arrester monitoring cloud platform is used to perform any of the methods described in the first aspect;

[0028] The main power transformer in the main network substation of the power grid and the distribution transformer in the distribution network substation are connected with lightning arresters and lightning arrester monitoring devices in sequence. The main network aggregation node is arranged in the main network substation of the power grid, connecting each lightning arrester monitoring device in the main network substation and the lightning arrester monitoring cloud platform. The distribution network aggregation node is arranged in the distribution network substation of the power grid, connecting each lightning arrester monitoring device in the distribution network substation and the lightning arrester monitoring cloud platform.

[0029] Lightning arresters, lightning arrester monitoring devices and lightning arrester monitoring terminals are connected in sequence to the high-voltage transmission lines and high-voltage distribution lines of the power grid;

[0030] The lightning arrester monitoring device connected to the main power transformer and the distribution transformer sends the collected operating data of the lightning arrester to the lightning arrester monitoring cloud platform, and the lightning arrester monitoring terminal connected to the high-voltage transmission line and the high-voltage distribution line sends the operating data of the lightning arrester collected by the lightning arrester monitoring device connected to it to the lightning arrester monitoring cloud platform.

[0031] Further, a lightning arrester, a lightning arrester monitoring device and a lightning arrester monitoring terminal connected in sequence to the high-voltage transmission line constitute a set of first detection units, and a plurality of the first detection units are provided in parallel;

[0032] A lightning arrester, a lightning arrester monitoring device and a lightning arrester monitoring terminal connected in sequence to the high-voltage distribution line constitute a set of second detection units, and a plurality of the second detection units are provided in parallel;

[0033] The main power transformer in the main grid substation and the distribution transformer in the distribution grid substation are connected with lightning arresters and lightning arrester monitoring devices in sequence, specifically:

[0034] A lightning arrester and a lightning arrester monitoring device are sequentially connected before the primary of the main power transformer to form a set of third detection units, and a plurality of third detection units are provided in parallel;

[0035] Each bay of the main power transformer is connected in sequence with a lightning arrester and a lightning arrester monitoring device to form a fourth detection unit;

[0036] A lightning arrester and a lightning arrester monitoring device are sequentially connected before the primary of the distribution transformer to form a set of fifth detection units, and a plurality of the fifth detection units are provided in parallel;

[0037] Each secondary compartment of the distribution transformer is connected in sequence with a lightning arrester and a lightning arrester monitoring device to form a sixth detection unit.

[0038] Furthermore, the arrester monitoring device and the main network aggregation node / the distribution network aggregation node are wirelessly connected via the LoRa network, and the main network aggregation node / the distribution network aggregation node / the arrester monitoring terminal and the arrester monitoring cloud platform are wirelessly connected via the mobile network.

[0039] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0040] The present invention provides a power grid power outage detection method and system. By analyzing the operating data of the lightning arrester collected by the lightning arrester monitoring device and the lightning arrester monitoring terminal, the widely distributed existing lightning arresters in the power grid are used to perform power grid power outage detection. The power outage area can be quickly and accurately found, and the judgment of whether the lightning arrester is damaged and the judgment of lightning strike / overvoltage events can be introduced, so that the cause of the power outage can be quickly determined, and targeted power supply restoration processing can be made. Since the lightning arrester monitoring device and the lightning arrester monitoring terminal use different power supplies, and the lightning arresters are set at various nodes of the power grid at different locations, it not only meets the "non-same source" and "double confirmation" requirements of the power supply department for power outage judgment, but also does not require a large amount of extra manpower and material resources to install new equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flow chart of a power grid power outage detection method corresponding to Embodiment 1 of the present invention;

[0042] Figure 2 It is a schematic diagram of the connection of the lightning arrester provided by an embodiment of the present invention in a local power grid;

[0043] Figure 3 It is a schematic diagram of the layout of a power grid power outage detection system in a power grid provided by an embodiment of the present invention;

[0044] Figure 4 is a flow chart of a power grid power outage detection method corresponding to Embodiment 2 of the present invention;

[0045] Figure 5 is a relationship diagram between the power outage time and the total leakage current of the lightning arrester provided by the embodiment of the present invention;

[0046] Figure 6 It is a schematic diagram of the three-level structure of the power supply system line provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0048] Embodiment 1, as Figure 1As shown, the present invention provides a power grid power outage detection method, comprising:

[0049] Obtaining a circuit structure diagram of the power grid and operation data of multiple lightning arresters collected by a lightning arrester monitoring terminal / arrester monitoring device in the power grid;

[0050] If the arrester is not degraded / damaged, the abnormal data in the operation data is screened out based on the preset first screening rule;

[0051] Based on the preset second screening rule, abnormal data caused by lightning strike events or overvoltage events are screened out and marked;

[0052] According to all abnormal data, a power grid blackout area distribution map is drawn on the basis of the circuit structure diagram.

[0053] The present invention analyzes the operating data of the lightning arrester collected by the lightning arrester monitoring device and the lightning arrester monitoring terminal, and uses the existing widely distributed lightning arresters in the power grid to perform power outage detection. It can quickly and accurately find the power outage area, introduce the judgment of whether the lightning arrester is damaged, and introduce the judgment of lightning strike / overvoltage events, so as to quickly judge the cause of the power outage, and thus make targeted power restoration processing. Since the lightning arrester monitoring device and the lightning arrester monitoring terminal use different power supply sources, and the lightning arresters are set at various nodes of the power grid at different locations, it not only meets the "non-same source" and "double confirmation" requirements of the power supply department for power outage judgment, but also does not need to consume a large amount of extra manpower and material resources to install new equipment.

[0054] Embodiment 2: Since the arrester is an important primary device in the power grid, its high voltage end is directly connected to the high voltage grid, and its low voltage end is connected to the earth. It can directly sense whether the grid is energized. Its connection relationship with the grid is as follows: Figure 2 As shown. The arrester is composed of multiple valve plates, and its main component is metal oxide (MOA). When the voltage at both ends is lower than the critical point of the action voltage, the impedance is in a high-resistance state, mainly capacitive components; after the voltage is higher than the critical point, the impedance drops sharply, and the arrester is instantly turned on. The arrester monitoring terminal / device mainly monitors the total leakage current Ix, resistive current Ir, harmonic components, impact current and occurrence time of the arrester. After long-term use and repeated exposure to large current shocks, the arrester will gradually deteriorate, showing an increase in the total leakage current Ix and a more significant increase in the resistive current Ir. It is manifested as a significant increase in the arrester temperature and a significant increase in the harmonic content, which further accelerates the deterioration of the arrester, resulting in a decrease in the arrester's ability to protect the safe operation of the power grid, and even an explosion, causing a major power outage in the power grid. Therefore, it is necessary to install an arrester monitoring terminal / device to monitor the working status of the arrester.

[0055] The arrester monitoring terminal generally monitors the operating status of the arrester on the transmission line. The monitored arrester is directly connected to the transmission line. The arrester monitoring device is installed to sample the total leakage current and impulse current of the arrester. One arrester monitoring terminal can monitor the status of three-phase arresters of one line at the same time. The arrester monitoring terminal is usually powered by solar energy and lithium batteries. The arrester monitoring device generally monitors the operating status of the arrester in the substation. The monitored arrester is directly connected to the incoming / outgoing line in the substation. The upper end of the arrester monitoring device is directly connected to the lower end of the arrester, and the lower end is connected to the protective ground. One arrester monitoring device only monitors the status of one arrester. The arrester monitoring device is usually powered by a large-capacity lithium battery.

[0056] like Figure 4 As shown, the present invention provides a power grid power outage detection method, comprising:

[0057] Step 1, check whether the operation data of the lightning arrester returned by the lightning arrester monitoring device and the lightning arrester monitoring terminal in the power grid are abnormal;

[0058] Step 2, checking whether the lightning arrester monitoring device and the lightning arrester monitoring terminal in the power grid have detected a lightning strike event;

[0059] Step 3: Preliminarily determine whether the power outage was caused by a lightning strike;

[0060] Step 4, determine again whether the power outage is caused by damage to the lightning arrester;

[0061] Step 5: Perform corresponding operations to restore power supply based on the results of the initial judgment and the re-judgment.

[0062] like Figure 5 As shown in the figure, it is a relationship diagram between the total leakage current of the arrester and the voltage, and Ix represents the total leakage current. When the total leakage current Ix is zero, it means that the voltage is zero, and it can be determined that the power grid is in a power outage state. Under normal circumstances, the total leakage current Ix is very small, for example: the total leakage current Ix of the arrester of a 110kV line is about 230μA, the total leakage current Ix of the arrester of a 220kV line is about 470μA, and the total leakage current Ix of the arrester of a 500kV line is about 1.2mA. When the arrester is subjected to an operating overvoltage shock, its total leakage current ranges from tens of A to hundreds of kA; when the arrester is subjected to a lightning voltage shock, its total leakage current ranges from tens of A to hundreds of kA. If the arrester is subjected to a voltage shock exceeding its tolerance, its performance will drop sharply, and it will not be able to effectively protect the safe operation of the power grid, and may even damage the safety of the line. Therefore, when the arrester is subjected to operating overvoltage, especially after a lightning strike, by checking whether there is a significant change in the total leakage current, the damaged arrester can be discovered and replaced in time to avoid damage to the power grid operation.

[0063] like Figure 6As shown, the arrester monitoring terminal and the arrester monitoring device can sample the arrester leakage full current Ix and resistive current Ir, as well as the time of lightning strike or overvoltage event, and regularly upload the leakage full current and resistive current to the arrester monitoring cloud platform through the aggregation node, and actively upload lightning strike or overvoltage events to the arrester monitoring cloud platform. The arrester monitoring cloud platform stores the initial value of the full leakage current Ix0 and the initial value of the resistive current Ir0 of all arresters, and compares them with the current arrester leakage full current and resistive current real-time values. If the leakage full current changes by more than 5%, expressed as Ix>1.05Ix0 and Ir>1.5Ir0, it means that the arrester has deteriorated and issued a yellow alarm for exceeding the standard, and the arrester is listed as a key observation object. Once the total leakage current of the arrester changes by more than 10%, which is expressed as Ix>1.1Ix0 and Ir>1.5Ir0, it means that the arrester is damaged and a red alarm is issued, and the corresponding instructions are issued to remind the user to replace the arrester as soon as possible. At the same time, the arrester monitoring cloud platform receives the lightning strike or overvoltage event information actively uploaded by the arrester monitoring terminal and the arrester monitoring device, so as to grasp the lightning strike or overvoltage area, and draw a lightning strike or overvoltage area map in combination with the power grid structure map drawn by the GIS geographic information system, and compare the power supply outage event to determine whether the power grid is caused by lightning strike or overvoltage.

[0064] Real-time monitoring of the data returned by the arrester monitoring device and the arrester monitoring terminal is performed to check whether there are any anomalies. If the total leakage current of at least two arresters is 0, the arrester monitoring device or the arrester monitoring terminal will alarm to confirm that a power outage has occurred in the power grid. If there was a lightning strike or overvoltage event before the power outage, the time of the event should be compared with the power outage time in a timely manner. If the time lines coincide, it can be preliminarily determined that the power outage was caused by a lightning strike or overvoltage event, and the power supply can be restored by reclosing the switch. If there was no lightning strike or overvoltage event before the power outage, the corresponding arrester should be checked immediately for damage, and the damaged arrester should be replaced as soon as possible to restore power.

[0065] When a power outage occurs in the power grid, since the arrester monitoring device and the arrester monitoring terminal are powered by large-capacity lithium batteries or lithium batteries combined with solar energy, they can continue to monitor the leakage current without being affected by the power outage, fully meeting the "non-same source" and "double confirmation" power outage judgment requirements put forward by the power supply department. And because the power grid has a power outage, the monitored arrester leakage current is zero at this time.

[0066] According to all the arrester monitoring terminals and arrester monitoring devices with zero leakage current, a regional map of the power outage range is drawn in combination with the lines where they are located. The drawing rules are as follows: if a power outage occurs on a high-voltage transmission line, the main grid substation connected to it and the high-voltage distribution lines under the secondary bus of the main power transformer connected to it will all be out of power, and at the same time, the low-voltage transformer connected to the high-voltage distribution line and its subordinate low-voltage lines will also all be out of power; if a power outage occurs on a high-voltage distribution line under the secondary bus of the main power transformer in the main grid substation, the distribution transformer connected to this high-voltage distribution line and its subordinate low-voltage distribution lines will all be out of power; if a power outage occurs on a low-voltage distribution line under the secondary bus of the distribution transformer, all users connected to this low-voltage distribution line will be out of power.

[0067] Embodiment 3, as Figure 3 As shown, the present invention provides a power grid power outage detection system, including a lightning arrester monitoring cloud platform, multiple lightning arrester monitoring terminals, multiple lightning arrester monitoring devices, multiple lightning arresters, a main network aggregation node and a distribution network aggregation node, wherein the lightning arrester monitoring cloud platform is used to execute the method provided in Example 1;

[0068] The main power transformer in the main network substation of the power grid and the distribution transformer in the distribution network substation are connected with lightning arresters and lightning arrester monitoring devices in sequence. The main network aggregation node is arranged in the main network substation of the power grid, connecting each lightning arrester monitoring device in the main network substation and the lightning arrester monitoring cloud platform. The distribution network aggregation node is arranged in the distribution network substation of the power grid, connecting each lightning arrester monitoring device in the distribution network substation and the lightning arrester monitoring cloud platform.

[0069] Lightning arresters, lightning arrester monitoring devices and lightning arrester monitoring terminals are connected in sequence to the high-voltage transmission lines and high-voltage distribution lines of the power grid;

[0070] The lightning arrester monitoring device connected to the main power transformer and the distribution transformer sends the collected operating data of the lightning arrester to the lightning arrester monitoring cloud platform, and the lightning arrester monitoring terminal connected to the high-voltage transmission line and the high-voltage distribution line sends the operating data of the lightning arrester collected by the lightning arrester monitoring device connected to it to the lightning arrester monitoring cloud platform.

[0071] Embodiment 4, the present invention provides a power grid power outage detection system, the layout in the power grid is as follows Figure 3As shown, the power grid and the power grid power outage detection system include: a lightning arrester monitoring cloud platform, a main grid substation and a distribution grid substation, wherein the lightning arrester monitoring cloud platform is used to execute the method provided in Example 1, the main grid substation is provided with a main grid aggregation node and a main power transformer, and the distribution grid substation is provided with a distribution grid aggregation node and a distribution transformer; the power plant is connected to the high-voltage transmission line for power supply, the primary of the main power transformer is connected to the high-voltage transmission line, and the secondary is connected to one end of the high-voltage distribution line, the primary of the distribution transformer is connected to the other end of the high-voltage distribution line, and the secondary is connected to the power user through the low-voltage distribution line; the lightning arrester monitoring terminal is connected to the high-voltage transmission line and the high-voltage distribution line, and the secondary of the main power transformer and the distribution transformer are connected to the lightning arrester monitoring device through multiple intervals; the lightning arrester monitoring device is respectively corresponding to the communication connection of the main grid aggregation node and the distribution grid aggregation node, and the main grid aggregation node and the distribution grid aggregation node communicate with the lightning arrester monitoring terminal to connect to the access node in the lightning arrester monitoring cloud platform.

[0072] Figure 3 In the figure, MOA represents lightning arrester, 1# main grid substation represents the first main grid substation in the grid, 1# high-voltage transmission line represents the first high-voltage transmission line in the grid, 1#MOA monitoring terminal represents the first lightning arrester monitoring terminal in the grid, 1# aggregation node represents the first aggregation node in 1# main grid substation, 1#MOA sensor represents the first lightning arrester sensor directly connected to the first high-voltage transmission line in the first main grid substation, LoRa represents the wireless LoRa communication module, 1-1# represents MOA sensor represents the first lightning arrester sensor connected to 1#MOA sensor, 1-2# represents The MOA sensor indicates the second arrester sensor connected to the 1# MOA sensor, the 1-3# MOA sensor indicates the third arrester sensor connected to the 1# MOA sensor, the 1# high-voltage distribution line indicates the first high-voltage distribution line in the power grid, the 1-1# low-voltage transmission line indicates the first low-voltage transmission line directly connected to the 1# high-voltage distribution line in the power grid, the 1MOA sensor indicates the first arrester sensor in the 1-1# low-voltage transmission line directly connected to the first high-voltage distribution line, the 1-1# aggregation node indicates the first aggregation node in the 1-1# low-voltage transmission line, and the 1-1-1# The MOA sensor indicates the first MOA sensor connected to the 1MOA sensor in the 1-1# low-voltage transmission line, the 1-1-2# MOA sensor indicates the second MOA sensor connected to the 1MOA sensor in the 1-1# low-voltage transmission line, the 1-1-3# MOA sensor indicates the third MOA sensor connected to the 1MOA sensor in the 1-1# low-voltage transmission line, and A indicates the connection point with the power grid.

[0073] According to the nonlinear characteristics of the total leakage current and voltage of the metal oxide arrester, as well as its low cost, large current capacity and good stability, it has been widely used in transmission and transformation lines. However, since the metal oxide arrester is installed outdoors, it will gradually deteriorate after long-term use or repeated overvoltage shocks, and even explode in severe cases, causing power outages in the power grid. People often use arrester monitoring devices to effectively monitor the operating status of the arrester. The arrester monitoring device can be divided into two types: the arrester monitoring device for substation lines and the arrester monitoring device for transmission lines. The arrester monitoring device for transmission lines mainly monitors the arrester monitoring device used for overhead transmission lines or underground cables. Since the transmission lines are scattered and unattended, most of them use wireless communication networks for data communication. Three through-core mutual inductors are usually installed on the three phases of a transmission line as the collection of arrester leakage current and impulse current. The arrester monitoring device used for the substation is generally set in the substation. Its setting is relatively centralized and there are dedicated personnel on duty. Most of them use the Internet of Things for data communication. Usually one sensor corresponds to one lightning arrester, and a monitoring meter is used in combination to collect the total leakage current and impulse current.

[0074] The arrester monitoring terminal is usually used on the power grid. It has a leakage current collection function and can collect the three-phase arrester leakage current at the same time through the A / D function. It has a wireless network communication module, which can interact with the background workstation through the wireless network communication module and report the real-time data monitored by the arrester to the background workstation. It has a real-time clock and event active reporting function. When the arrester has an overvoltage or the leakage current exceeds the limit (the leakage current is zero during a power outage), the event and the event that occurred are actively reported to the background workstation. It also has a lithium battery combined with solar energy as a working power supply, which can work normally even if the power grid is out of power. Here, the arrester monitoring terminal on the high-voltage distribution line is used to monitor the real-time data of the three-phase arrester leakage current Ix and the resistive current Ir in the high-voltage distribution line, and the arrester monitoring terminal on the high-voltage transmission line is used to monitor the real-time data of the three-phase arrester leakage current Ix and the resistive current Ir in the high-voltage transmission line.

[0075] Lightning arrester monitoring devices and aggregation nodes are generally used in substations. Each lightning arrester is connected to a lightning arrester monitoring device, and each line is composed of three phases ABC as a group. The grid incoming line is connected to the main power transformer after the lightning arrester, and the high-voltage distribution line is connected to the secondary of the main power transformer through the busbar. Each high-voltage distribution line is an interval, and each interval has a group of lightning arresters and lightning arrester monitoring devices connected to three phases ABC. The lightning arrester monitoring device collects leakage current according to the set collection cycle, and has a wireless LoRa communication module to upload the collected leakage full current to the aggregation node. When there is an overvoltage or the leakage full current exceeds the limit (the leakage full current is zero during a power outage), the event is actively reported to the aggregation node. The event is reported to the background workstation through the wireless network communication module of the aggregation node. At the same time, a large-capacity lithium battery is used as the power supply for the lightning arrester monitoring device, and the event can be reported even if the power grid is out of power.

[0076] The arrester monitoring cloud platform includes access nodes and background workstations. The background workstations have monitoring software and database servers. They can communicate with arrester monitoring terminals and arrester monitoring devices with wireless networks through Ethernet. It also has the functions of arrester degradation analysis, degraded arresters and faulty arresters identification. It has geographic information GIS function, which enables it to draw regional maps of each arrester monitoring terminal and arrester monitoring device where the power supply is cut off when the power grid is out of power. It also has the emergency handling plan function for major power outages. Operators can quickly complete major fault handling events according to the emergency handling plan for power outages.

[0077] The backend workstation and the access node are connected by wired communication through the local area network. The arrester monitoring terminals on the high-voltage transmission lines and high-voltage distribution lines communicate with the access nodes through the wireless network. The main network aggregation node and the distribution network aggregation node communicate with the arrester monitoring device through LoRa, and the main network aggregation node and the distribution network aggregation node communicate with the access node through the wireless network. The access node collects the real-time data such as the total current Ix and resistive current Ir of the arrester monitored by the arrester monitoring terminal of the high-voltage transmission line, the arrester monitoring device for each phase of each line before and after the main transformer in the main network substation, the arrester monitoring terminal of the high-voltage distribution line, and the arrester monitoring device for each phase of each line before and after the main transformer in the distribution network substation, as well as the alarm events such as lightning strike or overvoltage, current exceeding the upper limit, current exceeding the lower limit, and the time when the alarm event occurs.

[0078] Embodiment 5, the present invention provides a power grid power outage detection system, the layout in the power grid is as follows Figure 6 As shown, the power supply system can be divided into three levels according to the lines:

[0079] The first level is the electricity generated by the power plant through the 220kV high-voltage transmission line ( Figure 6The voltage of the L1 in the middle substation is stepped down to the primary of the main power transformer (set as BY1) of the 35kV substation. There are high-voltage control switches (set as K1-A and K1-B) at both ends of the high-voltage transmission line. There are two lightning arresters and lightning arrester monitoring terminals (set as BLT1A and BLT1B) on the high-voltage transmission line L1. The lightning arrester monitoring terminal is powered by solar energy + lithium battery and communicates with the main station through a wireless network. There are three lightning arresters MOA and meter-type lightning arrester monitoring devices (set as BLA1A, BLA1B, and BLA1C) in front of the primary of the main power transformer BY1 in the intermediate substation. The device is powered by a large-capacity lithium battery and can communicate wirelessly with the aggregation node (set as RTU1) through the LoRa module. The aggregation node RTU1 communicates indirectly with the main station through a wireless network.

[0080] Figure 6 In the figure, MOA represents lightning arrester, 1# main transformer represents the main power transformer connected to the high-voltage transmission line, 1-1# main transformer represents the main power transformer connected to the high-voltage distribution line, 1-1-1# main transformer represents the main power transformer connected to bay 1-1, 1-1-2# main transformer represents the main power transformer connected to bay 1-2, and 1-1-3# main transformer represents the main power transformer connected to bay 1-2.

[0081] The second level is the secondary of the main transformer BY1 in the intermediate substation and each bay, through the 35kV high-voltage distribution line (the first high-voltage distribution line is set as L1-1, the mth high-voltage distribution line is set as L1-m) to the primary of the 10kV distribution transformer step-down transformer (set as BY1-m). A switch (K1-a, a is 1 / 2 / 3, corresponding to bay 1, bay 2 and bay 3) is installed in front of each bay of the main transformer BY1 (bay 1, bay 2 and bay 3), and each bay of the main transformer BY1 (bay 1, bay 2 and bay 3) has a lightning arrester MOA and a lightning arrester monitoring device (set as BLA1- a A, BLA1- a B, BLA1- a C, a is 1 / 2 / 3, corresponding to bay 1, bay 2 and bay 3), and there are two lightning arresters MOA and lightning arrester monitoring terminals on each high-voltage distribution line (the lightning arrester monitoring terminal on the mth high-voltage distribution line is set as BLT1-mA, BLT1-mB). There are high-voltage control switches at both ends of the high-voltage distribution line (the switches at both ends of the m-th distribution line are set to K1-mA and K1-mB), and there are three lightning arrester monitoring devices in front of the distribution transformer BY1-1 (the m-th distribution line is set to BLA1-mA, BLA1-mB, and BLA1-mC).

[0082] The third level is the secondary bays of distribution transformer BY1-1 (bay 1-1, bay 1-2 and bay 1-3). Switches K1-1-1, K1-1-2 and K1-1-3 are respectively installed before bay 1-1, bay 1-2 and bay 1-3, and are connected to the primary of user's low-voltage transformer (set as BY1-mn) through low-voltage distribution lines (under the 1st high-voltage transmission line and the mth high-voltage distribution line, the nth low-voltage distribution line is set as L1-mn). Each interval of the secondary of distribution transformer BY1-m is equipped with lightning arrester and lightning arrester monitoring device (set as BLA1-m-nA, BLA1-m-nB, BLA1-m-nC), the low-voltage distribution line L1-mn is connected to the primary of the user's low-voltage transformer, and low-voltage control switches are also installed at both ends of the low-voltage distribution line (under the first high-voltage transmission line and the mth high-voltage distribution line, the switches at both ends of the nth low-voltage distribution line are set as K1-m-nA and K1-m-nB).

[0083] Figure 6 In the figure, BY1-1-1 represents the distribution transformer connected to the bay 1-1 of distribution transformer BY1-1, BY1-1-2 represents the distribution transformer connected to the bay 1-2 of distribution transformer BY1-1, and BY1-1-3 represents the distribution transformer connected to the bay 1-3 of distribution transformer BY1-1.

[0084] When the power grid is operating normally, the total leakage current monitored by the lightning arrester monitoring devices of the main grid substation and distribution grid substation and the lightning arrester monitoring terminals of the high-voltage transmission lines and high-voltage distribution lines is basically stable. At this time, all lightning arresters are marked as green.

[0085] When the total leakage current Ix of the A-phase arrester measured by the arrester monitoring terminal BLT1A of the high-voltage transmission and distribution line L1 changes by more than 5% of the starting value Ix0, the A-phase arrester of the arrester monitoring terminal BLT1A is marked in yellow to remind the user that the arrester has deteriorated. When the measured total leakage current Ix changes by more than 10% of the starting value Ix0, the A-phase arrester is marked in red to remind the user that the arrester has been damaged.

[0086] When the total leakage current Ix measured by the A-phase arrester monitoring device BLA1A in the intermediate substation bay 1 changes by more than 5% of the starting value Ix0, the arrester is marked in yellow and the user is reminded that the arrester has deteriorated. When the total leakage current Ix measured changes by more than 10% of the starting value Ix0, the arrester is marked in red and the user is reminded that the arrester has been damaged.

[0087] When the leakage current of the A-phase arrester monitoring device BLA1-2A of the secondary bay 2 of the main transformer BY1 in the intermediate substation is zero, the arrester monitoring device reports the leakage current exceeding the lower limit fault to the aggregation node RTU1 through the LoRa wireless communication module. After the aggregation node RTU1 receives the fault of the monitoring device BLA1-2A, it immediately reports the fault of the device together with the time of the aggregation node to the main station through the wireless network communication module. If the leakage current of a phase of the monitoring terminal BLT2A or BLT2B of the distribution line L1-2 is zero, the leakage current exceeding the lower limit of the terminal and the time of occurrence are immediately reported to the arrester monitoring cloud platform through the wireless network communication module. The arrester monitoring cloud platform makes a judgment based on the leakage current reported by other monitoring devices and monitoring terminals on the distribution line L1-2. If only the device is zero, it is concluded that the arrester or the arrester monitoring device has failed.

[0088] When multiple intervals of the secondary of the main transformer BY1 of the intermediate substation are out of power (for example, the line trips due to overload), the three lightning arrester monitoring devices of these intervals report the leakage full current exceeding the lower limit fault to the aggregation node through the LoRa wireless communication module. After the aggregation node receives the fault of the lightning arrester monitoring device, it immediately reports the fault of the device together with the time of the aggregation node to the lightning arrester monitoring cloud platform through the wireless network communication module. The lightning arrester monitoring terminal connected to the high-voltage distribution line detects that the leakage full current is zero, and immediately reports the leakage current exceeding the lower limit of the terminal and the time of occurrence to the lightning arrester monitoring cloud platform through the wireless network communication module. The lightning arrester monitoring cloud platform draws the conclusion that these lines are out of power based on the zero leakage full current fault reported by the lightning arrester monitoring device and the lightning arrester monitoring terminal on the line. Because the lightning arrester monitoring cloud platform stores the basic geographical location information of each lightning arrester monitoring terminal and device (i.e., the circuit structure diagram), the location of the device reported with zero leakage full current is intuitively presented. The arrester monitoring cloud platform also saves the emergency plan for power outages on the line, and the main station staff can handle emergencies according to the plan. The arrester monitoring cloud platform has the geographical location information of each arrester monitoring device and arrester monitoring terminal. The power supply department has formulated emergency plans for power outages on each line in advance according to the power consumption level of each line user. If it is found that the overload trip is caused, power can be immediately repeated to ensure power supply to important places such as hospitals and steel furnaces, and reduce power outage losses to a minimum.

[0089] When the high-voltage transmission line L1 trips due to lightning strike, the primary power of the main power transformer BY1 connected to the high-voltage transmission line L1 is cut off, and the lightning arrester monitoring terminals BLT1A and BLT1B of the high-voltage transmission line report the leakage current exceeding the lower limit (power outage) fault and the power outage time through the wireless network. The lightning arrester monitoring devices BLA1A, BLA1B, and BLA1C in front of the main power transformer BY1 in the intermediate substation and all monitoring devices BLA1-1~BLA1-n in all secondary intervals report the leakage current exceeding the lower limit (power outage) fault to the aggregation node through LoRa wireless communication, and the aggregation node reports it to the lightning arrester monitoring cloud platform through the wireless network. At the same time, all the high-voltage distribution line arrester monitoring terminals BLT1-1~BLT1-n connected to this main power transformer also detect that the leakage current is zero, and immediately report the leakage current exceeding the lower limit of the terminal and the time of occurrence to the arrester monitoring cloud platform through the wireless network communication module. The arrester monitoring cloud platform draws the conclusion that the high-voltage transmission line is out of power due to lightning strike based on the arrester monitoring device and terminal on this main transformer line reporting the zero leakage current fault at the same time. Because the arrester monitoring cloud platform stores the basic geographical location information of each terminal and device, the location of the equipment with zero leakage current reported is presented intuitively. The arrester monitoring cloud platform also saves the emergency plan for the power outage of the main line. If the on-duty personnel of the main station where the arrester monitoring cloud platform is located find that the arrester is damaged due to lightning strike, causing the high-voltage transmission line to fail and it is difficult to restore power supply for a while, they can immediately switch the distribution line where the important users are located to the normal distribution line to restore power supply to the important users.

[0090] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may 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.) containing computer-usable program codes.

[0091] 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 1A device that provides the functions specified in a block or multiple blocks.

[0092] 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.

[0093] 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 in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0094] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for detecting power outage in a power grid, characterized in that: include: Obtaining a circuit structure diagram of the power grid and operation data of multiple lightning arresters collected by a lightning arrester monitoring terminal / arrester monitoring device in the power grid; If the arrester is not degraded / damaged, filtering out abnormal data in the operation data based on a preset first screening rule; Based on the preset second screening rule, abnormal data caused by lightning strike events or overvoltage events are screened out and marked; Draw a power outage area distribution map of the power grid based on the circuit structure diagram according to all abnormal data; The operating data of the arrester includes the total leakage current, resistive current, lightning strike event occurrence time and overvoltage event occurrence time of the arrester; The filtering out abnormal data in the operation data based on a preset first filtering rule includes: If the total leakage current of a lightning arrester is 0, the data is abnormal data; The method of screening out abnormal data caused by a lightning strike event or an overvoltage event and marking the abnormal data based on a preset second screening rule includes: The generation time of the abnormal data is compared with the occurrence time of the lightning strike event and the occurrence time of the overvoltage event. If the two compared times are the same, the abnormal data is abnormal data caused by the lightning strike event or the overvoltage event, and it is marked. If the abnormal data is caused by the lightning strike event, it is marked as lightning strike abnormal data, and if the abnormal data is caused by the overvoltage event, it is marked as overvoltage abnormal data.

2. The power grid power outage detection method according to claim 1, characterized in that: The method further includes determining whether the arrester is degraded or damaged, including: If the total leakage current of the arrester changes by more than 5%, and the resistive current of the arrester changes by more than 50%, the arrester is degraded; If the total leakage current of the arrester changes by more than 10% and the resistive current of the arrester changes by more than 50%, the arrester is damaged.

3. The power grid power outage detection method according to claim 1, characterized in that: The method of drawing a power outage area distribution map of the power grid based on the circuit structure diagram according to all abnormal data includes: If the abnormal data comes from the arrester on the high-voltage transmission line, the main grid substation connected to the high-voltage transmission line in the circuit structure diagram and the high-voltage distribution lines under the secondary bus of the connected main power transformer are all marked as power outage areas, and the low-voltage transformer under the high-voltage distribution line in the circuit structure diagram and its subordinate low-voltage lines are also all marked as power outage areas; If the abnormal data comes from the lightning arrester on a high-voltage distribution line under the secondary busbar of the main transformer in the main grid substation, the distribution transformer connected to the high-voltage distribution line and its subordinate low-voltage distribution lines in the circuit structure diagram shall all be marked as power outage areas; If the abnormal data comes from the arrester on a low-voltage distribution line under the secondary bus of the distribution transformer, all users connected to this low-voltage distribution line in the circuit structure diagram will be marked as power outage areas; In addition, when a certain area is marked as a power outage area, the corresponding abnormal data label is marked on the power outage area, specifically including: if the abnormal data is lightning strike abnormal data, the corresponding power outage area is marked as a lightning strike power outage area; if the abnormal data is overvoltage abnormal data, the corresponding power outage area is marked as an overvoltage power outage area.

4. The method for detecting power outage in a power grid according to claim 3, characterized in that: After obtaining the power outage area distribution map of the power grid, the method further includes sending an emergency instruction according to the power outage information included in the power outage area distribution map of the power grid, wherein sending the emergency instruction according to the power outage information included in the power outage area distribution map of the power grid includes: If there is a lightning blackout area marked in the power grid blackout area distribution map, a closing command is sent to the power grid maintenance department corresponding to the lightning blackout area; If the power outage area distribution map of the power grid has a power outage area other than the lightning power outage area marked, a maintenance instruction is sent to the power grid maintenance department corresponding to the power outage area.

5. A power grid power outage detection system, characterized in that: The method comprises a lightning arrester monitoring cloud platform, a plurality of lightning arrester monitoring terminals, a plurality of lightning arrester monitoring devices, a plurality of lightning arresters, a main network aggregation node and a distribution network aggregation node, wherein the lightning arrester monitoring cloud platform is used to execute the method described in any one of claims 1 to 4; The main power transformer in the main network substation of the power grid and the distribution transformer in the distribution network substation are connected with lightning arresters and lightning arrester monitoring devices in sequence. The main network aggregation node is arranged in the main network substation of the power grid, connecting each lightning arrester monitoring device in the main network substation and the lightning arrester monitoring cloud platform. The distribution network aggregation node is arranged in the distribution network substation of the power grid, connecting each lightning arrester monitoring device in the distribution network substation and the lightning arrester monitoring cloud platform. Lightning arresters, lightning arrester monitoring devices and lightning arrester monitoring terminals are connected in sequence to the high-voltage transmission lines and high-voltage distribution lines of the power grid; The lightning arrester monitoring device connected to the main power transformer and the distribution transformer sends the collected operating data of the lightning arrester to the lightning arrester monitoring cloud platform, and the lightning arrester monitoring terminal connected to the high-voltage transmission line and the high-voltage distribution line sends the operating data of the lightning arrester collected by the lightning arrester monitoring device connected to it to the lightning arrester monitoring cloud platform.

6. The power grid power outage detection system according to claim 5, characterized in that: A lightning arrester, a lightning arrester monitoring device and a lightning arrester monitoring terminal connected in sequence on the high-voltage transmission line constitute a set of first detection units, and a plurality of the first detection units are provided in parallel; A lightning arrester, a lightning arrester monitoring device and a lightning arrester monitoring terminal connected in sequence to the high-voltage distribution line constitute a set of second detection units, and a plurality of the second detection units are provided in parallel; The main power transformer in the main grid substation and the distribution transformer in the distribution grid substation are connected with lightning arresters and lightning arrester monitoring devices in sequence, specifically: A lightning arrester and a lightning arrester monitoring device are sequentially connected before the primary of the main power transformer to form a set of third detection units, and a plurality of third detection units are provided in parallel; Each bay of the main power transformer is connected in sequence with a lightning arrester and a lightning arrester monitoring device to form a fourth detection unit; A lightning arrester and a lightning arrester monitoring device are sequentially connected before the primary of the distribution transformer to form a set of fifth detection units, and a plurality of the fifth detection units are provided in parallel; Each secondary compartment of the distribution transformer is connected in sequence with a lightning arrester and a lightning arrester monitoring device to form a sixth detection unit.

7. The power grid power outage detection system according to claim 5, characterized in that: The arrester monitoring device and the main network aggregation node / the distribution network aggregation node are wirelessly connected via the LoRa network, and the main network aggregation node / the distribution network aggregation node / the arrester monitoring terminal and the arrester monitoring cloud platform are wirelessly connected via the mobile network.

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