110KV circuit breaker state on-line monitoring system

Abstract

The utility model relates to an online state monitoring system for a 110KV circuit breaker. The online state monitoring system comprises an A-phase travel sensor, a B-phase travel sensor, a C-phase travel sensor, a main opening current sensor, an auxiliary opening current sensor, a closing current sensor, an energy storage current sensor, a vibration sensor, a data collector and a display control device, the data collector comprises eight AD circuits, a photoelectric isolation circuit, a 485 interface circuit, a high-precision clock circuit, an MCU main control circuit and a power supply circuit. According to the utility model, the vibration characteristics of the circuit breaker are not influenced by external interference and can be mutually verified with current characteristics, misjudgment caused by interference of the current characteristics is eliminated, the photoelectric isolation circuit is utilized to solve the problem that long-distance data transmission is interfered under a strong interference condition, and a path of current sensor is specially configured for monitoring aiming at the auxiliary opening, so that the monitoring accuracy is improved. And meanwhile, a stroke sensor is independently designed for each phase, so that the opening and closing time can be accurately measured, and the three-phase synchronism of the circuit breaker can be accurately measured.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit breaker monitoring field especially 110KV circuit breaker state on -line monitoring system. BACKGROUND

[0002] 110kv circuit breaker is important equipment of high voltage power system of our country, bears the important role of electric power control, can cut off or connect the load or no load current of various electrical equipment when the system is normal, when the system fault occurs, it can cut off the fault current, prevent the accident further expands, protects the line safety.

[0003] 110kv circuit breaker due to high working voltage, load current is big, the opening and closing speed is fast, and long -term in high voltage, big current, strong electromagnetic field's outdoor harsh environment, the equipment often appears rust, jam, structure loose, local short circuit, slow division slow combination, even refuse to move and so on Fault, seriously influence the safe operation of power grid.

[0004] Obviously, the mechanical characteristic of 110kv circuit breaker is the important basis for judging the working condition of circuit breaker, but because the working voltage level of 110kv circuit breaker is high, the action speed is too fast, the monitoring difficulty is extremely big, therefore at present on the market there is no mature technology for the state on -line monitoring of 110kv circuit breaker, can only wait for the power failure repair time to detect the equipment. Because the safety hidden danger of equipment cannot be found and eliminated in time, leads to equipment to work with disease, until the occurrence of safety accident, causes the serious economic loss even the personnel casualty major safety accident.

[0005] There are some online monitoring technologies for 110kV voltage level GIS on the market, but they are not suitable for monitoring 110KV circuit breakers. As described in CN 205720541 U, 110kV GIS monitoring equipment includes partial discharge, GIS gas micro-water state, and circuit breaker mechanical properties. The "mechanical property displacement sensor indirectly obtains the stroke value through the voltage change of the displacement sensor connected to the moving contact link and can calculate the corresponding speed value", that is, the output of this stroke sensor is an analog voltage. However, the working condition of 110kV circuit breakers is complex, with high voltage level and large load current, and there is strong electromagnetic interference, so the output analog voltage is easily disturbed. Moreover, the interphase distance of 110KV circuit breakers is usually 1.75 meters, and the data collector is generally installed in the operating box of the circuit breaker. That is, the data line between the farthest displacement sensor and the data collector needs to be at least 4 meters long. The analog output voltage of the stroke sensor is generally 0~5V. The voltage loss of such a long line is usually more than 0.2V, and the loss of voltage will cause serious distortion of the monitoring results. At the same time, 110kv circuit breakers produce strong interference electromagnetic signals during operation. Under such working conditions, long-line transmission of analog signals will inevitably be disturbed, and the superposition of voltage loss and signal interference will cause the monitoring equipment to fail to obtain the correct circuit breaker stroke information. Therefore, this method is not suitable for 110kV circuit breakers.

[0006] 110kV circuit breakers are different from closed GIS combined electrical apparatus. 110kV works outdoors and is not completely sealed. The metal cavity of the main shaft and transmission structure of the circuit breaker often appears rust due to the influence of rain and snow, which causes the transmission components of the circuit breaker to jam or even the circuit breaker to refuse to operate. In order to detect such hidden dangers early, it is obviously not enough to rely solely on the current action waveform of the circuit breaker opening and closing action and energy storage action to make a judgment, because 110kv circuit breakers produce strong interference electromagnetic fields during operation, causing the monitored current waveform to be distorted, and further causing the equipment transmission components to be misjudged as abnormal.

[0007] Secondly, 110kV circuit breakers are different from conventional circuit breakers. In order to ensure that the circuit breaker can break the fault current when the power system fails, 110kV circuit breakers are designed with main and auxiliary opening circuits. Therefore, the action current monitoring of 110kV circuit breakers needs to monitor the main and auxiliary opening circuits simultaneously. Conventional circuit breaker characteristic monitoring equipment does not have this function.

[0008] Furthermore, the phase distance of the 110kV circuit breaker is generally more than 1.75 meters, that is, the transmission connecting rod between two phases is at least 1.75 meters long, and it is obviously difficult to ensure the synchronization of such a long linkage transmission device, so the three-phase synchronization of the 110kV circuit breaker is particularly important, and therefore the three-phase main shaft of the circuit breaker needs to be monitored at the same time, the accurate opening and closing time of each phase is obtained, and then the three-phase synchronization parameter is obtained, instead of monitoring the main shaft of only one phase and using the opening and closing time of the one phase to replace the time of the other two phases as in the conventional circuit breaker. Content of the utility model

[0009] The utility model aims at overcoming the defects of the prior art and provides a 110KV circuit breaker state on-line monitoring system which can accurately monitor the working state of the 110kV circuit breaker and accurately find the fault of the circuit breaker.

[0010] In order to achieve the above object, the utility model adopts the technical scheme of a 110KV circuit breaker state on-line monitoring system which comprises an A-phase stroke sensor, a B-phase stroke sensor, a C-phase stroke sensor, a main opening current sensor, an auxiliary opening current sensor, a closing current sensor, an energy storage current sensor, a vibration sensor, a data collector and a display control device.

[0011] The A-phase stroke sensor, the B-phase stroke sensor and the C-phase stroke sensor are used for sensing the position change of the whole action process in real time during the opening and closing process of the circuit breaker and sending the position information to the data collector.

[0012] The main opening current sensor, the auxiliary opening current sensor, the closing current sensor and the energy storage current sensor are used for sensing the current information on the monitored operating coil during the opening and closing process and sending the current information to the data collector.

[0013] The vibration sensor is used for monitoring the overall vibration information of the circuit breaker in real time and sending the overall vibration information to the data collector.

[0014] The data collector is used for collecting the data of all the sensors in real time and uploading the collection results to the display control device.

[0015] The display control device analyzes and processes the data collected by the data collector.

[0016] Preferably, the data collector comprises an 8-channel AD circuit, an optoelectronic isolation circuit, a 485 interface circuit, a high-precision clock circuit, an MCU main control circuit and a power supply circuit.

[0017] The 8-channel AD circuit is used for sampling the output analog signals of the main opening current sensor, the auxiliary opening current sensor, the closing current sensor, the energy storage current sensor and the vibration sensor.

[0018] The photoelectric isolation circuit connects the three-path travel sensor, converts the output pulse signal of the three-path travel sensor into high and low levels, and sends the MCU master control circuit for collection and counting.

[0019] The 485 interface circuit is used for realizing data interaction between the MCU master control circuit and the display control device.

[0020] The high-precision clock circuit is used for improving the clock precision of the MCU master control circuit sampling and scheduling, and ensuring the high precision of the collected data.

[0021] The MCU master control circuit is used for scheduling control of the working process of the data collector and preprocessing of the collected data.

[0022] The power supply circuit is used for converting an external power supply into a working voltage required by each circuit.

[0023] Preferably, the 485 interface circuit is provided with electrostatic protection and lightning surge protection.

[0024] Preferably, the power supply circuit adopts a multi-stage voltage conversion mode, first converts the external power supply into ±5V, and then converts +5V into required +12V or +24V according to the requirement.

[0025] Preferably, the A-phase travel sensor, the B-phase travel sensor, and the C-phase travel sensor are connected to the data collector in a wired manner to realize power supply and data collection in a wired manner.

[0026] Preferably, the main opening and closing current sensor, the auxiliary opening and closing current sensor, the closing current sensor, and the energy storage current sensor adopt an open-close design and are clamped on the power supply line of the opening and closing coil.

[0027] Preferably, the range of the main opening and closing current sensor, the auxiliary opening and closing current sensor, and the closing current sensor exceeds 1.5 times of the maximum value of the rated opening and closing action current.

[0028] Preferably, the maximum range of the energy storage current sensor is greater than 1.2 times of the maximum value of the energy storage starting surge current.

[0029] Preferably, the vibration sensor is short-time sampled by the data collector at a fixed time interval when the 110KV circuit breaker is not operated for opening and closing, to determine whether there is a structure loosening condition during the daily operation of the circuit breaker; during the opening and closing operation and energy storage of the 110KV circuit breaker, the data collector synchronously performs high-speed sampling on the vibration sensor to assist in determining whether the 110KV circuit breaker has a jamming or loosening condition.

[0030] Preferably, the display control device adopts an integrated industrial control computer, which is directly installed in the operating box of the 110kV circuit breaker.

[0031] Thanks to the technical scheme, the utility model has the following advantages compared with the prior art:

[0032] 1. Since the electromagnetic interference of the 110kv circuit breaker is serious, especially the power supply is easily interfered, the opening and closing current is easily interfered by external interference to cause waveform distortion, and the distorted waveform can be misjudged as the abnormal transmission structure of the circuit breaker; if the transmission equipment of the circuit breaker is abnormal, not only the current characteristics will change accordingly, but also the vibration characteristics will change accordingly, the vibration characteristics of the circuit breaker are not affected by external interference, and the current characteristics can be verified with each other, the misjudgment caused by the interference of the current characteristics is eliminated, and the accuracy of fault judgment is improved.

[0033] 2. Since the distance between the 110kv circuit breaker phases is very long, the external interference is serious, the data line of the stroke sensor is easily interfered, and the pulse signal output by the sensor is easily distorted, thereby causing the monitoring accuracy to decrease, the utility model solves the problem of long-distance data transmission interference under strong interference condition by using the photoelectric isolation circuit, that is, as long as the voltage is higher than the threshold value, the high level (or the opposite) is output, otherwise the low level (or the opposite) is output, so even if the pulse signal is interfered and distorted, the overall level will not be changed, and then it can be correctly identified.

[0034] 3. Since the 110kv circuit breaker has main and auxiliary two-way opening, the traditional monitoring device can only monitor one-way opening, therefore the utility model is specially configured with a current sensor for monitoring the auxiliary opening, and the main and auxiliary opening loops can be monitored at the same time.

[0035] 4. Since the three-phase synchronism of the 110kv circuit breaker is very important, and the conventional monitoring device cannot measure the index, therefore the utility model separately designs a stroke sensor for each phase, accurately measures the opening and closing time, and then accurately measures the three-phase synchronism of the circuit breaker. BRIEF DESCRIPTION OF DRAWINGS

[0036] The technical scheme of the utility model will be further described below in combination with the drawings:

[0037] ATTACHMENT Figure 1 The utility model relates to a frame diagram of the 110KV circuit breaker state online monitoring system.

[0038] ATTACHMENT Figure 2 The utility model relates to a frame diagram of the data collector in the utility model. DETAILED DESCRIPTION

[0039] The utility model will be further described in detail in combination with the drawings and specific embodiments.

[0040] Appendix Figure 1 The 110KV circuit breaker online status monitoring system of this utility model includes an A-phase travel sensor, a B-phase travel sensor, a C-phase travel sensor, a main trip current sensor, an auxiliary trip current sensor, a closing current sensor, an energy storage current sensor, a vibration sensor, a data acquisition unit, and a display and control device.

[0041] The display and control device is responsible for collecting, storing, analyzing, displaying, and forwarding the data collected by the data acquisition device, and providing alarm prompts for parameters exceeding the standard or abnormal deterioration trends.

[0042] Furthermore, the display and control device adopts an integrated industrial control computer (ICC), preferably a 7-inch screen ICC, which can be directly installed in the operating box of a 110kV circuit breaker.

[0043] Furthermore, the display and control device load will upload the analysis results and monitoring data to the next higher level monitoring system.

[0044] Furthermore, the communication protocol between the display and control device and the upper-level monitoring system follows the interface requirements of the upper-level system, with the 61850 protocol being preferred.

[0045] The function of the A-phase travel sensor, B-phase travel sensor, and C-phase travel sensor is to sense the position changes in real time during the opening and closing of the circuit breaker, and to convert the position information into digital signals and output them to the data acquisition unit.

[0046] Furthermore, the A-phase travel sensor, B-phase travel sensor, and C-phase travel sensor all use the same type of sensor. The specific type is determined based on the circuit breaker structure, with photoelectric encoders, magnetic grating angular velocity sensors, and laser rangefinders being preferred.

[0047] Furthermore, 110KV circuit breakers typically use a B-phase main shaft to drive both A-phase and C-phase shafts. Therefore, the B-phase main shaft structure is relatively complex, while the A-phase and C-phase structures are symmetrical. Consequently, the mounting base for the B-phase travel sensor needs to be designed separately, while the mounting bases for the A-phase and C-phase travel sensors can be interchangeable.

[0048] Furthermore, the aforementioned travel sensor is connected to the data acquisition unit via a wired connection, enabling both power supply and data acquisition in a wired manner.

[0049] The current sensor is used to sense the current information on the monitored operating coil during the opening and closing process, and convert it into an analog voltage output to the data acquisition unit.

[0050] Furthermore, the main trip current sensor, auxiliary trip current sensor, and closing current sensor adopt an open-close design, which is clamped on the power lines of the trip and closing coils.

[0051] Further, the range of the main opening current sensor, the auxiliary opening current sensor, and the closing current sensor should exceed 1.54 times the maximum value of the rated opening and closing operation current, because the size of the opening and closing operation current is closely related to the operating voltage, and if the operating voltage decreases, the opening and closing operation current will increase accordingly. According to the specification, the opening operation voltage range is 65% to 120% of the rated operation voltage, i.e., the opening operation current range is 0.83 to 1.54 times the rated operation current; the closing operation voltage range is 85% to 110% of the rated operation voltage, i.e., the closing operation current range is 0.91 to 1.17 times the rated operation current.

[0052] Further, the maximum value of the opening and closing operation current of the 110kV circuit breaker is usually about 2A, so the maximum range of the opening and closing current sensor should not be less than 3.1A, preferably 5A.

[0053] Further, the opening and closing operation current sensor is preferably SAH05C2.

[0054] Further, the maximum range of the energy storage current sensor should be greater than 1.2 times the maximum value of the energy storage starting surge current, otherwise the energy storage starting surge current cannot be completely monitored, and overload cutting phenomenon may occur

[0055] Further, the maximum value of the energy storage starting surge current of the 110kV circuit breaker is usually about 10A, so the maximum range of the energy storage current sensor is usually selected to be more than 12A, preferably 15A.

[0056] Further, the energy storage operation current sensor is preferably SAH15C2.

[0057] The vibration sensor is used to monitor the overall vibration information of the circuit breaker in real time, and converts the vibration information into an analog voltage output to the data acquisition device

[0058] Further, the vibration sensor can be a vibration acceleration sensor or a vibration speed sensor, or a vibration amplitude sensor.

[0059] Further, when the 110KV circuit breaker is not in the opening and closing operation, the data acquisition device performs short-time sampling on the vibration sensor at a fixed time interval to determine whether there is a structure loosening during the daily operation of the circuit breaker.

[0060] During the opening and closing operation and energy storage of the 110KV circuit breaker, the data acquisition device synchronously performs high-speed sampling on the vibration sensor to assist in determining whether the 110KV circuit breaker has sticking, loosening, etc.

[0061] The data acquisition device is used to collect the data of all sensors in real time, and upload the collection results to the display and control device.

[0062] Furthermore, the data acquisition unit and the display and control device are connected via a 485 line to achieve data transmission.

[0063] Furthermore, the MODBUS protocol is preferred as the communication protocol between the data acquisition unit and the display and control device.

[0064] Furthermore, the data acquisition unit and all sensors are connected by cables, which contain data cables and power cables.

[0065] Furthermore, such as Figure 2 As shown, the data acquisition unit includes an 8-channel AD circuit, a 485 interface circuit, an opto-isolation circuit, a high-precision clock circuit, an MCU main control circuit, and a power supply circuit.

[0066] The function of the 8-channel AD circuit is to sample the output analog signals (0~5V) of the main trip current sensor, auxiliary trip current sensor, closing current sensor, energy storage current sensor, and vibration sensor.

[0067] Furthermore, the AD7903 is preferred as the main chip for the 8-channel AD circuit.

[0068] The opto-isolation circuit connects to three travel sensors, converts the output pulse signals of the three travel sensors into high and low levels, and sends them to the MCU chip for acquisition and counting.

[0069] Furthermore, the phase spacing of a 110kV circuit breaker is usually around 1.75 meters. If the control box is close to the A-phase main shaft, the wiring distance between the C-phase main shaft and the control box is about 5 meters. Since the 110kV circuit breaker operates under high voltage (110kV) and high current (1250A~3500A) conditions, the electromagnetic field around the circuit breaker is extremely complex. The 5-meter-long data line and power line will definitely be interfered with by external signals. If the output signal of the travel sensor is not processed, it will lead to distorted monitoring results or even failure of the monitoring function.

[0070] The function of the opto-isolation circuit is to protect the output pulse signal of the stroke sensor. As long as the output pulse amplitude of the stroke sensor exceeds a certain threshold, even if the pulse waveform is distorted, the circuit can still operate normally, thereby ensuring high-precision monitoring of the three-phase stroke.

[0071] The 485 interface circuit is used to enable data interaction between the monitoring host and the display and control device.

[0072] Furthermore, since the 110KV circuit breaker operates outdoors, additional protective measures must be added to the 485 interface circuit, such as electrostatic discharge protection and lightning surge protection.

[0073] Further, the main chip of the 485 interface circuit is preferably a model with isolation function, preferably ADM2483BRWZ.

[0074] The high-precision clock circuit provides a high-precision clock signal for the MCU, improves the clock precision of sampling and scheduling, and ensures the high precision of collected data. Since the three-phase synchronization requirement of the 110KV circuit breaker is less than 3ms, the clock precision of the built-in MCU main control circuit is low (usually ±1ppm), which is not suitable for occasions with high time precision requirements. Therefore, an external high-precision clock must be used.

[0075] Further, the high-precision clock crystal oscillator is preferably a constant-temperature crystal oscillator, and the precision is preferably ±0.5ppb.

[0076] The MCU main control circuit schedules and controls the working process of the data collector and pre-processes the collected data.

[0077] Further, the MCU main control circuit uses an external high-precision clock.

[0078] Further, the main chip of the MCU main control circuit is preferably an STM32 series.

[0079] The power supply circuit converts external power (usually AC220V or DC220V) into the working voltage required by each circuit, such as ±5V, +12V, +24V, etc.

[0080] Further, the power supply circuit uses a multi-stage voltage conversion method, first converts the external power into ±5V, and then converts +5V into the required +12V or +24V as needed.

[0081] Further, the power supply circuit needs to be configured with a corresponding EMI protection circuit.

[0082] The data collector has the following collection rules for the above-mentioned travel sensor and current sensor:

[0083] When the circuit breaker has no opening or closing action, only the three-way travel sensor is sampled, and when the opening or closing action is detected, all sensors start high-speed sampling. The sampling time for the opening action is 200mS, and the sampling time for the closing action is 200mS. Then, the energy storage current sensor and the vibration sensor start low-speed sampling, and the total sampling time for the vibration is 15S.

[0084] When the circuit breaker has no opening or closing action, the vibration sensor is sampled at low speed, and the sampling time interval can be set, usually set to 5 minutes.

[0085] The above time length is formulated according to the parameters of a conventional 110KV circuit breaker, and can be adjusted according to actual conditions if necessary. The principle is that the sampling time length needs to ensure that the relevant characteristics of the action can be completely collected. The reason for the sampling time length of 200mS of the opening and closing action is that the opening and closing action time of the conventional 110KV circuit breaker is between 20~100mS, and in order to ensure data integrity, the sampling time length of the action current and stroke of the opening and closing is 200mS; the energy storage time length of the conventional 110KV circuit breaker is usually within 10S, and if it exceeds 15S, it can be identified as an abnormality, so the sampling time length of the energy storage vibration and the energy storage action current is set to 15S.

[0086] The above is only a specific application example of the present application, and does not constitute any limitation on the protection scope of the present application. Any technical solution formed by equivalent transformation or equivalent replacement falls within the protection scope of the present application.

Claims

1. A 110 KV circuit breaker condition on-line monitoring system characterized by: The circuit comprises an A-phase stroke sensor, a B-phase stroke sensor, a C-phase stroke sensor, a main opening current sensor, a secondary opening current sensor, a closing current sensor, an energy storage current sensor, a vibration sensor, a data collector and a display control device. The A-phase stroke sensor, the B-phase stroke sensor and the C-phase stroke sensor are used to sense the position change of the whole process in real time during the opening and closing of the circuit breaker, and send the position information to the data collector. The main opening current sensor, the secondary opening current sensor, the closing current sensor and the energy storage current sensor are used to sense the current information on the monitored operating coil during the opening and closing, and send the information to the data collector. The vibration sensor is used to monitor the overall vibration information of the circuit breaker in real time, and send the information to the data collector. The data collector is used to collect the data of all the sensors in real time, and upload the collection results to the display control device. The display control device analyzes and processes the data collected by the data collector.

2. The 110 KV circuit breaker condition on-line monitoring system according to claim 1, characterized in that: The data collector comprises an 8-channel AD circuit, an optical isolation circuit, a 485 interface circuit, a high-precision clock circuit, an MCU main control circuit and a power supply circuit. The 8-channel AD circuit is used to sample the output analog signals of the main opening current sensor, the secondary opening current sensor, the closing current sensor, the energy storage current sensor and the vibration sensor. The optical isolation circuit connects with the three stroke sensors, converts the output pulse signals of the three stroke sensors into high and low levels, and sends them to the MCU main control circuit for collection and counting. The 485 interface circuit is used to realize the data interaction between the MCU main control circuit and the display control device. The high-precision clock circuit is used to improve the clock precision of the MCU main control circuit sampling and scheduling, and ensure the high precision of the collected data. The MCU main control circuit is used to schedule and control the working process of the data collector, and preprocess the collected data. The power supply circuit is used to convert the external power supply into the working voltage required by each circuit.

3. The 110 KV circuit breaker condition on-line monitoring system according to claim 2, characterized in that: The 485 interface circuit is provided with electrostatic protection and lightning surge protection.

4. The 110 KV circuit breaker condition on-line monitoring system as claimed in claim 2, wherein: The power supply circuit adopts a multi-stage voltage conversion mode, first converts the external power supply into ±5V, and then converts +5V into +12V or +24V as needed.

5. The 110 KV circuit breaker condition on-line monitoring system as claimed in claim 1, wherein: The A-phase stroke sensor, the B-phase stroke sensor and the C-phase stroke sensor are connected with the data collector by a wired mode, and realize power supply and data collection in a wired mode.

6. The 110 KV circuit breaker condition on-line monitoring system as claimed in claim 1, wherein: The main opening current sensor, the secondary opening current sensor, the closing current sensor and the energy storage current sensor adopt an open-close design and are clamped on the power supply lines of the opening and closing coils.

7. The 110 KV circuit breaker condition on-line monitoring system as claimed in claim 1, wherein: The range of the main opening current sensor, the secondary opening current sensor and the closing current sensor exceeds 1.5 times of the maximum value of the rated opening and closing operating current.

8. The 110 KV circuit breaker condition on-line monitoring system as claimed in claim 1, wherein: The maximum range of the energy storage current sensor is greater than 1.2 times of the maximum value of the energy storage starting surge current.

9. The 110 KV circuit breaker condition on-line monitoring system as claimed in claim 1, wherein: The vibration sensor is short-time sampled by the data collector at fixed time intervals when the 110KV circuit breaker is not operated, so as to determine whether the structural part is loose during daily operation of the circuit breaker; and the vibration sensor is synchronously high-speed sampled by the data collector during the opening and closing operation and energy storage of the 110KV circuit breaker, so as to assist in determining whether the 110KV circuit breaker is stuck or loose.

10. The 110 KV circuit breaker condition on-line monitoring system as claimed in claim 1, wherein: The display control device adopts an integrated industrial control computer and is directly installed in the operation box of the 110kV circuit breaker.

Images