500kV transformer substation cable trench intelligent drainage system

Abstract

The invention discloses an intelligent drainage system for a 500kV transformer substation cable trench, and relates to the field of cable trench drainage, the system is composed of a main control host and three drainage units arranged in cable trenches in different equipment areas, each drainage unit comprises a set of low-power monitoring drainage terminals and a set of high-power monitoring drainage terminals, and high-low matching is formed. And the main control computer communicates with each terminal through an LORA wireless network, so that remote multi-point real-time monitoring and mean value calculation of the water level height and the rising speed in the ditch are realized. The main control host performs fault detection before drainage, and starts drainage pumps with different powers to drain water in a grading manner by executing a grading intelligent drainage strategy; through redundant backup, it is ensured that each partition still has the drainage capacity when a single point of failure occurs. According to the invention, anti-interference remote data transmission is realized by using LORA communication; the drainage efficiency of the cable trench is improved through a hierarchical intelligent drainage strategy; and through double-terminal redundant backup, the system is ensured to still have the drainage capacity when a single device fails, and the drainage reliability is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the field of cable trench drainage, in particular to a 500kV substation cable trench intelligent drainage system. BACKGROUND

[0002] With the deepening of the construction of smart grid, the safe and stable operation of substations as key nodes of the power system is crucial. The internal environment of the cable trench, which is an important channel for laying power cables in the station, directly affects the reliability of power supply. Due to geographical environment, climate conditions and trench structure and other factors, the problem of water accumulation in the cable trench is widespread, which has become a major hidden danger threatening the safe operation of substations. In recent years, the Internet of Things technology has been widely applied in the field of power equipment state monitoring, providing a new technical path for the intelligent operation and maintenance of substations. Under this background, how to use modern communication technology and intelligent control methods to realize accurate monitoring and efficient disposal of water accumulation in the cable trench has become a technical problem to be solved in the field of substation operation and maintenance management.

[0003] The existing cable trench drainage system has obvious deficiencies: the traditional monitoring mainly relies on manual inspection, which is difficult to find water accumulation hazards in time and has a serious response lag problem. The communication mode adopted by the existing automatic system has weak anti-interference ability, poor transmission reliability in the strong electromagnetic environment of substations, and often data interruption. The drainage terminal configuration is single, lacks power grading and redundancy design, cannot accurately allocate drainage resources according to the severity of water accumulation, and completely loses drainage capacity when equipment fails. At the same time, the system generally lacks a perfect fault diagnosis mechanism, and cannot realize the intelligent linkage of early warning, control and fault handling. These technical defects make it difficult for the existing system to meet the high standard requirements of 500kV large substations for cable trench drainage reliability. SUMMARY

[0004] The purpose of the present application is to provide a 500kV substation cable trench intelligent drainage system, which can realize anti-interference remote data transmission, improve the efficiency of cable trench drainage, and ensure that the system still has drainage capacity when a single device fails, thereby improving the reliability of drainage.

[0005] To achieve the above purpose, the present application provides the following solutions: The application provides a 500kV substation cable trench intelligent drainage system, the system comprises: a first drainage unit, a second drainage unit, a third drainage unit and a master control host; the first drainage unit, the second drainage unit and the third drainage unit are respectively arranged in the cable trenches of the 35kV equipment area, the 220kV equipment area and the 500kV equipment area in the substation; the first drainage unit, the second drainage unit and the third drainage unit all comprise: a first monitoring drainage terminal and a second monitoring drainage terminal; the first monitoring drainage terminal and the second monitoring drainage terminal are arranged at a preset interval distance; the drainage power of the first drainage terminal is less than that of the second drainage terminal; the first drainage unit, the second drainage unit and the third drainage unit are all connected with the master control host through LORA communication wireless connection; the master control host is provided with a LORA communication module; the master control host is used for controlling the first drainage unit, the second drainage unit and the third drainage unit to respectively carry out multi-point real-time monitoring and early warning on the water level height and the water level rising speed of the cable trenches where they are located, to obtain the water level height average value and the water level rising speed average value, to carry out fault detection on the first monitoring drainage terminal and the second monitoring drainage terminal when draining, and then to control the first monitoring drainage terminal and the second monitoring drainage terminal to carry out hierarchical intelligent drainage on the cable trenches where they are located according to the fault detection result according to the hierarchical intelligent drainage strategy, while transmitting the drainage processing log to the master control host in real time, and to control the first monitoring drainage terminal and the second monitoring drainage terminal to be redundant backups of each other when not draining.

[0006] According to the specific embodiments provided in the application, the following technical effects are disclosed: The application is composed of one master control host and three drainage units respectively arranged in the cable trenches of 35kV, 220kV and 500kV equipment areas by adopting a sub-area distributed architecture. Each drainage unit is configured with a first monitoring drainage terminal and a second monitoring drainage terminal, and the two terminals are arranged at a preset interval to facilitate separate detection and drainage and improve the drainage efficiency. And the differential design of low power and high power is adopted to form power complementation. Each drainage unit is connected with the master control host through LORA wireless communication technology, which overcomes the strong electromagnetic interference environment of the substation and realizes stable and reliable remote data transmission. When the system is working, the master control host performs multi-point real-time monitoring on each sub-area cable trench, and realizes accurate early warning by calculating the mean value of water level height and the mean value of water level rising speed. In the drainage control link, the system first executes the fault detection program, and then starts the hierarchical intelligent drainage strategy based on the detection results: according to the water level threshold, the drainage terminals of different powers are started and stopped dynamically to realize the optimal allocation of drainage resources; at the same time, through the double-terminal redundant backup mechanism, it is ensured that each sub-area still maintains the drainage capacity when a single device fails, and the system reliability is improved. Through anti-interference communication, intelligent drainage strategy and equipment redundant backup, the application solves the problems of response lag and insufficient reliability of the traditional substation cable trench drainage system. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0008] Fig. 1 A structural connection diagram of a 500kV substation cable trench intelligent drainage system provided by the embodiments of the present application.

[0009] Fig. 2 A structural connection diagram of a monitoring drainage terminal provided by the embodiments of the present application.

[0010] The drawings show that: 1, the first drainage unit; 2, the second drainage unit; 3, the third drainage unit; 4, the master control host; 5, the first monitoring drainage terminal; 6, the second monitoring drainage terminal; 51, the suction cup antenna; 52, the RS485 to LORA module; 53, the liquid level meter module; 54, the relay module; 55, the AC contactor; 56, the power supply; 57, the water pump. DETAILED DESCRIPTION

[0011] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0012] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] Example 1, such as Figs. 1-2 As shown, this embodiment provides an intelligent drainage system for cable trenches in 500kV substations. The system includes: a first drainage unit 1, a second drainage unit 2, a third drainage unit 3, and a main control host 4.

[0014] The first drainage unit 1, the second drainage unit 2, and the third drainage unit 3 are respectively installed in the cable trenches of the 35kV equipment area, the 220kV equipment area, and the 500kV equipment area within the substation. Each of the first drainage unit 1, the second drainage unit 2, and the third drainage unit 3 includes: a first monitoring drainage terminal 5 and a second monitoring drainage terminal 6. The first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 are installed at a preset interval. The drainage power of the first drainage terminal is less than that of the second drainage terminal.

[0015] The first drainage unit 1, the second drainage unit 2, and the third drainage unit 3 are all connected to the main control host 4 via LORA wireless communication; the main control host 4 is equipped with a LORA communication module.

[0016] The main control unit 4 is used to control the first drainage unit 1, the second drainage unit 2 and the third drainage unit 3 to perform multi-point real-time monitoring and early warning of water level height and water level rise rate in their respective cable trenches, and obtain the average water level height and the average water level rise rate. During drainage, the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 are first checked for faults. Then, based on the fault detection results, the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 are controlled to perform graded intelligent drainage in their respective cable trenches according to the graded intelligent drainage strategy. At the same time, the drainage processing log is transmitted to the main control unit 4 in real time. When not draining, the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 are controlled to be redundant backups of each other.

[0017] Furthermore, the hierarchical intelligent drainage strategy specifically includes: 1) When the fault detection results show that both the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 are fault-free, perform the following operations: When the average water level is less than the first preset average height, no drainage will be carried out, and only a warning of dampness in the ditch will be issued.

[0018] When the water level height average is greater than or equal to the first preset height average or the water level rising speed average is greater than the first preset speed, the first monitoring drainage terminal 5 is controlled to start drainage, and a first-stage water accumulation warning is issued.

[0019] When the water level height average is greater than or equal to the second preset height average or the water level rising speed average is greater than the second preset speed, the second monitoring drainage terminal 6 is controlled to start drainage, the second monitoring drainage terminal 6 is controlled to stop drainage, and a second-stage water accumulation warning is issued.

[0020] When the water level height average is greater than or equal to the third preset height average and the water level rising speed average is greater than the second preset speed, the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 are controlled to start drainage at the same time, and a third-stage water accumulation warning is issued.

[0021] 2) When the fault detection result is that any one of the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 has a fault, the following operations are performed: the monitoring drainage terminal with a fault among the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 is powered off, and the monitoring drainage terminal without a fault is controlled to drain at full load.

[0022] Further, the first preset height is 10 cm; the second preset height is 30 cm; and the third preset height is 100 cm.

[0023] Further, the first preset speed is 1 cm / min; and the second preset speed is 5 cm / min.

[0024] Further, the multi-point real-time monitoring is that the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 simultaneously detect the water level height and the water level rising speed at the positions thereof, and the water level height average and the water level rising speed average are obtained by taking the average values, respectively.

[0025] Further, the first monitoring drainage terminal 5 and the second monitoring drainage terminal 6 each include: a suction cup antenna 51, an RS485-to-LORA module 52, a liquid level meter module 53, a relay module 54, an alternating current contactor 55, a power supply 56, and a water pump 57.

[0026] The suction cup antenna 51 is connected to the RS485-to-LORA module 52 through a coaxial cable.

[0027] The RS485-to-LORA module 52 is connected to the liquid level meter module 53 and the relay module 54, respectively; and the liquid level meter module 53 is used to monitor the water level height and the water level rising speed in real time.

[0028] The relay module 54 is connected to the alternating current contactor 55.

[0029] The alternating current contactor 55 is connected to the water pump 57 and the power supply 56 input end, respectively.

[0030] The power supply 56 is connected with the RS485-to-LORA module 52, the liquid level meter module 53, the relay module 54, the AC contactor 55 and the water pump 57 respectively; the power supply 56 is used for supplying power for the RS485-to-LORA module 52, the liquid level meter module 53, the relay module 54, the AC contactor 55 and the water pump 57.

[0031] Further, the liquid level meter module 53 is a magnetostrictive liquid level sensor.

[0032] Further, the liquid level meter module 53 is in close contact with the water pump 57 through a heat-conducting material, and the liquid level meter module 53 has a temperature measurement function.

[0033] Optionally, the liquid level meter module 53 can also be an ultrasonic water level meter, a radar water level meter, a float type water level meter or a pressure type water level meter.

[0034] Optionally, in addition to the AC contactor 55, the water pump 57 can also be controlled through a solid-state relay.

[0035] Optionally, the main control host 4 is also used for performing a water accumulation diffusion model prediction, and the main control predicts a water accumulation diffusion path based on historical data and real-time monitoring values, and optimizes a hierarchical intelligent drainage strategy.

[0036] In actual application, the system of the application is composed of one control host and a plurality of execution terminals (drainage terminals), the main control host 4 and the drainage terminals communicate with each other through a LORA wireless network, the control host is deployed in a main control room of a transformer substation, and the execution terminals are deployed in each water level monitoring point needing drainage in a cable trench.

[0037] The control host includes a computer host, a USB-to-RS485 module, a LORA communication module and a suction cup antenna 51, the computer host is connected with the USB-to-RS485 module through a USB port, the RS485 module is connected with the LORA communication module through a 485 bus, and the suction cup antenna 51 is connected with the RS485-to-LORA module 52 through a coaxial cable.

[0038] Each execution terminal (drainage terminal) includes a 220V-to-12V power supply 56 module, a relay module 54, a liquid level meter module 53, an RS485-to-LORA module 52, a suction cup antenna 51, an AC contactor 55, and a water pump 57. The 220V-to-12V power supply 56 module is connected to the relay module 54, the liquid level meter module 53, and the RS485-to-LORA module 52 through the power supply 56 line to provide 12v power supply for them. The relay module 54, the liquid level meter module 53, and the RS485-to-LORA module 52 are connected through the 485 bus for data communication. After receiving the control signal, the relay module 54 drives the AC contactor 55 to control the start and stop of the water pump 57.

[0039] In actual application, the system architecture of the present application is as follows: 1. Sensing layer: deploy magnetostrictive liquid level meter (precision error ≤ ±0.5 cm) to collect water depth data in real time.

[0040] 2. Transmission layer: use LORA wireless communication module (transmission distance ≥ 5 km, rate ≥ 2 kbps) to build a low-power wide-area communication network.

[0041] 3. Control layer: through the relay module 54, the AC contactor 55, and the driving drainage pump 57 to realize automatic start and stop (threshold value can be set in the control host).

[0042] 4. Management and control platform: generate water level trend warning based on data analysis algorithm, support Web / mobile terminal remote monitoring and historical data backtracking.

[0043] Further, the fault detection process is as follows: according to the order of water level sensor diagnosis, relay module 54 diagnosis, AC contactor 55 diagnosis, water pump 57 temperature diagnosis, and drainage efficiency diagnosis, the faults are detected in turn, and the specific process is as follows: 1) Water level sensor diagnosis: query water level data every 1 minute, if the query fails, the fault detection result is water level sensor failure.

[0044] 2) Relay module 54 diagnosis: query the state of the relay module 54 every 5 minutes, if the query fails, the fault detection result is relay module 54 failure.

[0045] 3) AC contactor 55 diagnosis: when the water level sensor diagnosis and the relay module 54 diagnosis are both normal, after the drainage instruction is issued by the host computer 4, if no contactor attraction feedback is received, the fault detection result is AC contactor 55 failure.

[0046] 4) Water pump 57 temperature diagnosis: monitor the temperature of the water pump 57 through the liquid level meter module 53, when the temperature of the water pump 57 exceeds the temperature threshold, the fault detection result is water pump 57 over-temperature failure.

[0047] 5) drainage efficiency diagnosis: when the water level sensor diagnosis, relay module 54 diagnosis, AC contactor 55 diagnosis and water pump 57 temperature diagnosis are all normal, if the water level does not decrease after the water pump 57 is started, the fault detection result is that the water pump 57 is faulty.

[0048] Further, the RS485 to LORA module 52 adopts a 433MHz frequency band and can perform adaptive rate adjustment.

[0049] In actual application, the present application designs a regional alarm mechanism for the special structure of the cable trench of a substation. Taking a 500kV substation as an example, it is divided into three alarm regions, i.e. the main transformer and 35kV equipment region, the 220kV equipment region and the 500kV equipment region. In order to improve reliability and reduce false positives and false negatives, at least two sets of monitoring drainage terminals, i.e. the first drainage terminal and the second drainage terminal, are set in each equipment region, forming a redundant backup to ensure that the corresponding partition does not lose drainage and alarm capabilities in the case of a single point failure. Meanwhile, the two water pumps 57 form a high-low combination in power, the first drainage terminal is a small power pump, and the second drainage terminal is a large power pump.

[0050] In addition, due to the large area and long length of the cable trench of a substation, the straight-line distance from the main control room to the farthest end reaches 500 meters. If cable is used, it is easy to be disturbed by other power cables laid in the same trench. If optical fiber communication equipment is laid, the cost and construction cost are too high, so wireless communication mode is selected. Since the amount of data to be transmitted is small (only water level data and water pump 57 state data are transmitted), the LORA scheme with low communication rate but long communication distance is selected.

[0051] The technical effects of the present application are as follows: The application is composed of one master host and three drainage units respectively arranged in the cable trenches of 35kV, 220kV and 500kV equipment areas by adopting a regional distributed architecture. Each drainage unit is configured with a first monitoring drainage terminal and a second monitoring drainage terminal, and the two terminals are arranged at a preset interval to facilitate separate detection and drainage and improve the drainage efficiency. And the differential design of low power and high power is adopted to form power complementation. Each drainage unit is connected with the master host through LORA wireless communication technology, which overcomes the strong electromagnetic interference environment of the substation and realizes stable and reliable remote data transmission. When the system is working, the master host performs multi-point real-time monitoring on each partition cable trench, and realizes accurate early warning by calculating the mean value of water level height and the mean value of water level rising speed. In the drainage control link, the system first executes the fault detection program, and then starts the hierarchical intelligent drainage strategy based on the detection results: according to the water level threshold, the drainage terminals with different powers are started and stopped dynamically to realize the optimal allocation of drainage resources; at the same time, through the double-terminal redundant backup mechanism, it is ensured that each partition still maintains the drainage capacity when a single device fails, and the system reliability is improved. Through the anti-interference communication, intelligent drainage strategy and equipment redundant backup, the application solves the problems of response lag and insufficient reliability of the traditional substation cable trench drainage system.

[0052] The technical features of the above embodiments can be combined arbitrarily, and to make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0053] The principles and implementation modes of the application are described by applying specific examples in this paper, and the above embodiment description is only used to help understand the method and its core idea of the application; at the same time, for those skilled in the art, according to the idea of the application, the specific implementation mode and application range will be changed. In conclusion, the content of the specification should not be understood as a limitation of the application.

Claims

1. A smart drainage system for cable trenches in 500kV substations, characterized in that, The system includes: a first drainage unit, a second drainage unit, a third drainage unit, and a main control unit; The first drainage unit, the second drainage unit, and the third drainage unit are respectively installed in the cable trenches of the 35kV equipment area, the 220kV equipment area, and the 500kV equipment area within the substation; each of the first drainage unit, the second drainage unit, and the third drainage unit includes: a first monitoring drainage terminal and a second monitoring drainage terminal; the first monitoring drainage terminal and the second monitoring drainage terminal are installed at a preset interval; the drainage power of the first drainage terminal is less than the drainage power of the second drainage terminal; The first drainage unit, the second drainage unit, and the third drainage unit are all wirelessly connected to the main control host via LoRa communication; the main control host is equipped with a LoRa communication module. The main control unit is used to control the first drainage unit, the second drainage unit and the third drainage unit to perform multi-point real-time monitoring and early warning of water level height and water level rise rate in their respective cable trenches, and to obtain the average water level height and the average water level rise rate. During drainage, the first monitoring drainage terminal and the second monitoring drainage terminal are first checked for faults. Then, based on the fault detection results, the first monitoring drainage terminal and the second monitoring drainage terminal are controlled to perform graded intelligent drainage in their respective cable trenches according to the graded intelligent drainage strategy. At the same time, the drainage processing log is transmitted to the main control unit in real time. When not draining, the first monitoring drainage terminal and the second monitoring drainage terminal are controlled to be redundant backups of each other.

2. The intelligent drainage system for 500kV substation cable trenches according to claim 1, characterized in that, The hierarchical intelligent drainage strategy specifically includes: When the fault detection results show that both the first and second monitoring drainage terminals are fault-free, the following operations are performed: When the average water level is less than the first preset average height, no drainage will be carried out, only a warning of dampness in the ditch will be issued. When the average water level is greater than or equal to the first preset average water level or the average water level rise rate is greater than the first preset rate, the first monitoring and drainage terminal is controlled to start drainage and issue a first-level water accumulation warning. When the average water level is greater than or equal to the second preset average height or the average water level rise rate is greater than the second preset rate, control the second monitoring drainage terminal to start drainage, control the second monitoring drainage terminal to stop drainage, and issue a level two flood warning. When the average water level is greater than or equal to the third preset average water level and the average water level rise rate is greater than the second preset rate, the first monitoring drainage terminal and the second drainage terminal are controlled to start drainage simultaneously and issue a level three flood warning. When the fault detection result indicates that either the first monitoring drainage terminal or the second monitoring drainage terminal is faulty, the following operations are performed: Power off the faulty monitoring and drainage terminal in the first and second monitoring and drainage terminals, and control the fault-free monitoring and drainage terminal to drain at full load.

3. The intelligent drainage system for 500kV substation cable trenches according to claim 2, characterized in that, The first preset height is 10cm; the second preset height is 30cm; and the third preset height is 100cm.

4. The intelligent drainage system for 500kV substation cable trenches according to claim 2, characterized in that, The first preset speed is 1 cm / min; the second preset speed is 5 cm / min.

5. The intelligent drainage system for 500kV substation cable trenches according to claim 1, characterized in that, Multi-point real-time monitoring involves the first and second monitoring drainage terminals simultaneously detecting the water level height and water level rise rate at their respective locations, and taking the average values ​​to obtain the average water level height and average water level rise rate.

6. The intelligent drainage system for 500kV substation cable trenches according to claim 1, characterized in that, Both the first and second monitoring drainage terminals include: a suction cup antenna, an RS485 to LORA module, a level gauge module, a relay module, an AC contactor, a power supply, and a water pump; The suction cup antenna is connected to the RS485 to LORA module via a coaxial cable; The RS485 to LORA module is connected to the level gauge module and the relay module respectively; the level gauge module is used to monitor the water level height and the water level rise rate in real time. The relay module is connected to the AC contactor; The AC contactor is connected to the water pump and the power input terminal respectively; The power supply is connected to the RS485 to LORA module, the level gauge module, the relay module, the AC contactor, and the water pump, respectively; the power supply is used to supply power to the RS485 to LORA module, the level gauge module, the relay module, the AC contactor, and the water pump.

7. The intelligent drainage system for 500kV substation cable trenches according to claim 6, characterized in that, The level gauge module is a magnetostrictive level sensor.

8. The intelligent drainage system for 500kV substation cable trenches according to claim 6, characterized in that, The level gauge module is in close contact with the water pump through a heat-conducting material, and the level gauge module has a temperature measurement function.

9. The intelligent drainage system for 500kV substation cable trenches according to claim 8, characterized in that, The fault detection process is as follows: faults are detected sequentially in the order of water level sensor diagnosis, relay module diagnosis, AC contactor diagnosis, water pump temperature diagnosis, and drainage efficiency diagnosis. The specific process is as follows: Water level sensor diagnosis: The water level data is queried every minute. If the query fails, the fault detection result is that the water level sensor is faulty. Relay module diagnostics: Check the relay module status every 5 minutes. If the check fails, the fault detection result is that the relay module is faulty. AC contactor diagnosis: If the water level sensor diagnosis and relay module diagnosis are both normal, and no contactor engagement feedback is received after the main control host issues a drainage command, the fault detection result is an AC contactor fault. Water pump temperature diagnosis: The water pump temperature is monitored by the level gauge module. When the water pump temperature exceeds the temperature threshold, the fault detection result is water pump over-temperature fault. Drainage performance diagnosis: If the water level sensor diagnosis, relay module diagnosis, AC contactor diagnosis and water pump temperature diagnosis are all normal, and the water level does not drop after the water pump is turned on, the fault detection result is a water pump failure.

10. The intelligent drainage system for 500kV substation cable trenches according to claim 6, characterized in that, The RS485 to LORA module uses the 433MHz frequency band and is capable of adaptive rate adjustment.

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