Circuit breaker state mechanical characteristic on-line monitoring system

Abstract

The utility model relates to a circuit breaker state mechanical characteristic on-line monitoring system comprising a photoelectric encoder used for detecting the position of a disconnecting link of a GIS device circuit breaker, and a Hall current sensor used for detecting the on-off state of the GIS device circuit breaker. The photoelectric encoder is connected with the signal output end of the Hall current sensor, the signal output end of the Hall current sensor is connected with the signal input end of the IED device, and the sending end of the IED device is connected with the main controller. Two data are integrated to analyze and process collected signals, useful signals are extracted to judge the operation state of the circuit breaker, abnormal conditions such as clamping stagnation and jamming of an iron core of the circuit breaker can be analyzed, the fault development trend is predicted, and early warning is carried out.

Description

Technical Field

[0001] The utility model belongs to the field of high-voltage switch equipment, in particular to an online monitoring system for mechanical characteristics of a circuit breaker state. Background Art

[0002] At present, circuit breakers and GIS are one of the most important equipment in the power system, shouldering the dual tasks of control and protection, and the reliability of their performance is related to the safe operation of the power system. The statistical survey on high-voltage circuit breaker failures conducted by the International Large Power Grid Conference and my country Electric Power Research Institute shows that most of the circuit breaker failures (70% of major failures and 86% of minor failures) occur in the mechanical mechanism, mainly involving the operating mechanism, monitoring device and auxiliary device.

[0003] Relevant statistics show that more than half of the maintenance costs of substations are spent on switches, and 60% of the costs are spent on minor repairs and routine maintenance of circuit breakers; in addition, according to statistics, 10% of circuit breaker failures are caused by incorrect maintenance. The maintenance of circuit breakers requires complete disassembly, which has high time and cost costs, reaching 1 / 3 to 1 / 2 of the purchase cost of circuit breakers. Disassembly and reassembly have a high probability of bringing new fault hazards, so the online monitoring and fault and diagnosis system IED (intelligence elecronic device) for circuit breakers and GIS mechanical characteristics came into being. The application of IED conducts online monitoring of mechanical characteristics and status evaluation of circuit breakers and GIS in grid operation, which simplifies the regular equipment maintenance work of the power system. After installation and operation, fault hazard alarms can be issued in advance to avoid major power grid accidents.

[0004] However, the current function of IED devices mainly stays on the detection of electrical current data, and its detection and early warning function is very simple and weak. Utility Model Content

[0005] In view of the above situation, in order to overcome the defects of the prior art, the utility model provides a circuit breaker online monitoring system which monitors the status of the circuit breaker in operation in real time, thereby providing a basis for the power equipment to achieve the transition from "preventive maintenance" to "condition-based maintenance", thereby effectively reducing the equipment maintenance costs and significantly improving the service life of the circuit breaker itself and the economic benefits of operation.

[0006] According to the changes of coil current over time during each opening and closing process of various circuit breakers, the changing waveform contains a series of important information such as the working conditions of the electromagnet itself, the controlled lock, and the transmission mechanism during the operation process. The utility model continuously monitors the opening and closing coil current signals of the circuit breaker in operation, and collects information on the rotation angle of the rotating shaft of the GIS device circuit breaker knife switch, analyzes and processes the collected signals, and extracts useful signals to judge the operating status of the circuit breaker. It can analyze abnormal conditions such as stagnation and jamming of the circuit breaker core, predict the development trend of the fault and issue an early warning. The mechanism status detection report issued by the system can guide the substation to carry out targeted status maintenance of the switch, which can not only save a lot of funds and manpower invested in regular maintenance, but also reduce the number of spare parts invested in equipment, avoid unnecessary material waste, and also play a role in extending the service life of the equipment and protecting the environment.

[0007] Smart grid puts forward "five" requirements for the intelligence of primary power equipment. The online monitoring and status of circuit breakers and GIS mechanical characteristics and home diagnosis system realizes the "status visualization". At the same time, this system has the functions of digital measurement, networked control, integrated functions, and interactive information. It is an important IED device for intelligent high-voltage switchgear.

[0008] Specifically, an online monitoring system for mechanical characteristics of circuit breaker status is provided, which includes: a mechanical position sensor for detecting the position of a circuit breaker switch of a GIS device, the mechanical position sensor is a photoelectric encoder, the photoelectric encoder includes a light source, an optical code disk and a photosensitive element, the optical code disk shaft of the photoelectric encoder is coaxially installed with the shaft of the circuit breaker switch of the GIS device, and the photoelectric encoder can convert the angular displacement on the shaft of the circuit breaker switch of the GIS device into pulses or digital quantities through photoelectric conversion.

[0009] An electrical quantity sensor used to detect the opening and closing status of the circuit breaker of the GIS device. The electrical quantity sensor is a Hall current sensor. The current signal busbar of the high-voltage circuit breaker opening and closing coil passes through the center of the Hall sensor to detect the circulating current of the opening and closing coil of the GIS device.

[0010] It also includes an IED device, the signal output ends of the photoelectric encoder and the Hall current sensor are connected to the signal input end of the IED device, and the sending end of the IED device is connected to the main controller.

[0011] Preferably, it also includes a density micro-water sensor for collecting gas status to detect the micro-water content and dew point value of the SF6 gas humidity in the GIS device. The signal output end of the density micro-water sensor is connected to the signal input end of the IED device, and the sending end of the IED device is connected to the main controller.

[0012] Preferably, the IED device includes a signal conditioning circuit, a sampling chip and a single-chip microprocessor which are sequentially connected in signal, and the single-chip microprocessor is connected to the main controller through a transmitting end. The system uses a signal that is very sensitive to signal reactions and can measure signals of waveforms such as DC, AC, and pulses. The current signals of the photoelectric encoder, the Hall current sensor, and the density micro-water sensor are filtered and converted into voltage signals through the signal conditioning circuit; secondly, the voltage signal is amplified through the isolation amplifier circuit, and then the voltage signal is converted into a digital signal through the sampling chip. The sampling result is sent to the single-chip microprocessor, and the single-chip microprocessor processes the collected data and transmits it to the host computer of the main controller through the serial port; the host computer monitoring interface displays the current curve related to the opening / closing, the breaking current waveform, etc., and the circuit breaker can be preliminarily judged whether there is an abnormality according to the coil current waveform characteristics, and a diagnostic opinion can be given.

[0013] Beneficial effects of the utility model:

[0014] 1) Powerful online analysis of mechanical properties

[0015] The mechanical characteristic monitoring device IED (intelligence elecronic device) is installed in the intelligent component cabinet. The sensor collects information such as stroke, opening and closing coil current, etc., and transmits it to the mechanical state monitoring device IED in real time. After receiving the monitoring data fed back by each sensor, the device analyzes the monitoring quantity according to a specific state evaluation algorithm, and issues early warning, alarm and other signals. At the same time, it also sends the monitoring data to the upper network in the form of MMS (a message form in the IEC61850 communication protocol). By collecting the mechanism movement stroke / time curve, the current waveform of the opening (closing) coil, and the opening and closing current waveform, they are used together to judge the GIS device circuit breaker, and can make more accurate judgments on the possible situations such as the stroke state of the GIS device circuit breaker, speed change, wear of mechanical and transmission components, refusal to move due to jamming, looseness of the release device, and motor failure.

[0016] 2) Accurate reporting of action parameters

[0017] After each action, the system gives standard parameters of the circuit breaker such as travel, opening distance, overtravel, average speed, opening (closing) speed, energy storage status, opening and closing current, etc.

[0018] 3)Easy installation and high integration

[0019] A photoelectric angle displacement sensor is installed at the end of the rotating shaft of the circuit breaker of the GIS device. The whole set of online monitoring device is small in size and can be directly installed in the mechanism box. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a structural distribution diagram of the on-line monitoring system for mechanical characteristics of circuit breaker status of the utility model;

[0021] Figure 2 This is a schematic diagram of the installation of the photoelectric encoder of the utility model;

[0022] Figure 3 This is the front view of the IED device of the utility model;

[0023] Figure 4 This is a top view of the IED device of the utility model with part of the housing removed;

[0024] Figure 5 This is a three-dimensional diagram of the IED device of the utility model with part of the housing removed;

[0025] Figure 6 This is a schematic diagram of the IED device housing of the utility model;

[0026] Figure 7 Physical picture of the photoelectric encoder of the utility model.

[0027] In the figure: 1. Host computer; 2. IED device; 3. Hall current sensor; 4. Photoelectric encoder; 5. Density and micro-water sensor; 21. Main body shell; 22. Circuit breaker communication display PCB board; 23. Switching power supply; 24. DC and AC sampling PCB board; 25. Signal input terminal of IED device. DETAILED DESCRIPTION

[0028] The above and other technical contents, features and functions of the present invention are described in detail below with reference to the attached Figures 1 to 7 The embodiments are described in detail.

[0029] In this embodiment, a circuit breaker state mechanical characteristic online monitoring system includes:

[0030] A mechanical quantity position sensor for detecting the position of the circuit breaker of the GIS device, which is a photoelectric encoder 4, which includes a light source, an optical code disk and a photosensitive element. The optical code disk shaft of the photoelectric encoder is coaxially installed with the shaft of the circuit breaker of the GIS device. The photoelectric encoder can convert the angular displacement on the shaft of the circuit breaker of the GIS device into a pulse or digital signal through photoelectric conversion; an electrical quantity sensor for detecting the opening and closing state of the circuit breaker of the GIS device, which is a Hall current sensor 3. The current signal busbar of the opening and closing coil of the high-voltage circuit breaker passes through the center of the Hall sensor to detect the circulating current of the opening and closing coil of the GIS device; the Hall current sensor 3 is a commercially available product

[0031] It also includes an IED device 2, the signal output end of the photoelectric encoder and the Hall current sensor is connected to the signal input end of the IED device, and the sending end of the IED device is connected to the main controller. The hardware structure of the IED device can be selected according to actual needs and electrical related standards, such as the main body shell 21; the circuit breaker communication display PCB board 22; the switching power supply 23; the DC, AC sampling PCB board 24; the signal input end 25 of the IED device, etc., which are all existing technologies and commercially available products.

[0032] In addition, the IED device may include a signal conditioning circuit, a sampling chip and a single-chip microprocessor which are sequentially connected in signal, and the single-chip microprocessor is connected to the main controller host computer 1 through a transmitting end.

[0033] The circuit breaker state mechanical characteristic online monitoring system provided in the present embodiment adopts a closed-loop magnetic compensation Hall current sensor which is very sensitive to signal response and can measure DC, AC, pulse and other waveforms. The busbar of the opening and closing coil current signal (opening and closing coil loop line) of the high-voltage circuit breaker to be measured passes through the center of the Hall sensor, and the collected current signal is filtered and converted into a voltage signal through the signal conditioning circuit; secondly, the voltage signal is amplified by the isolation amplifier circuit, and then the voltage signal is converted into a digital signal through the sampling chip, and the sampling result is sent to the single-chip microprocessor, and the collected opening and closing current data and energy storage motor current data are processed and transmitted to the host computer through the serial port; the monitoring interface displays the opening / closing coil current curve, the energy storage motor current curve, the breaking current waveform, etc. According to the coil current waveform characteristics, it can be preliminarily judged whether the circuit breaker has an abnormal situation, and a diagnostic opinion is given. The photoelectric encoder itself is a commercially available product. The contribution of this embodiment is that the photoelectric encoder is specifically installed on the rotating shaft of the circuit breaker knife switch, and the current signal of the high-voltage circuit breaker opening and closing coil is combined with the mechanical angle change signal of the rotating shaft of the circuit breaker knife switch, and the combined signal is used for online monitoring and judgment.

[0034] In the online monitoring system of mechanical characteristics of circuit breaker status, the IED device collects the characteristic signals of the monitored object in real time through the mechanical and electrical quantity sensors installed on the circuit breaker and GIS mechanism components, and performs online data processing and status analysis of the signals through the IED device based on the DSP signal processing chip and POWERPC embedded system. The IED device communicates with the substation network using the MMS message transmission protocol, displays the mechanical characteristic parameters of the corresponding actions of the circuit breaker mechanism on the integrated software platform of the station control layer server terminal, draws the moving contact stroke curve and the operating coil current waveform, and issues a status analysis report of the mechanism. The items monitored by the device for the circuit breaker mechanism operation basically cover most of the contents of the power outage maintenance test, and the data obtained by its monitoring can completely replace the power outage maintenance test data.

[0035] Figure 3-Figure 6A specific IED device is given, which is implemented with a standardized structure, that is, it can be a 19-inch chassis to ensure the convenience of engineering installation. The overall device style can be selected. It can monitor both single-phase and three-phase. The IED function distribution is clear, including CB mechanical characteristics monitoring plug-in, SF6 monitoring plug-in, input plug-in, exchange plug-in, main CPU plug-in, power supply plug-in, panel module, etc. It can be flexibly matched and expanded according to user needs. The mechanical characteristics online monitoring CB monitoring plug-in single board can monitor a set of mechanisms, and the SF6 density and micro-water monitoring plug-in single board can monitor 8 gas chamber signals at the same time. A set of IED devices can monitor 3 sets (phases) of mechanisms at the same time.

[0036] After the opening (closing) coil current acquisition and processing system is built, it can be tested on the 110k V SF6 circuit breaker. For example, when testing the circuit breaker, the Hall current sensor is passed through the opening coil and closing coil circuits of the operating mechanism, as well as the energy storage motor circuit, and three closing and three opening operations are performed in sequence. The system effectively records the current waveform during the operation and gives the characteristic value extraction results. According to each moment of the three closing current characteristic values ​​and the corresponding current amplitude, it is uploaded to the upper computer monitoring software to draw the current curve. In this way, it can be judged whether the iron core is stuck during the closing action, or abnormal waveforms are displayed and alarm prompts are given.

[0037] The SF6 monitoring plug-in also includes a density micro-water sensor 5 for collecting gas status, detecting the micro-water content and dew point value of the SF6 gas humidity in the GIS device. The signal output end of the density micro-water sensor is connected to the signal input end of the IED device, and the sending end of the IED device is connected to the main controller.

[0038] The above description is only for illustrating the present invention, and it should be understood that the present invention is not limited to the above embodiments, and various variations that conform to the concept of the present invention are within the protection scope of the present invention.

Claims

1. A circuit breaker status mechanical characteristics online monitoring system, characterized in that: include: A mechanical position sensor for detecting the position of a GIS device circuit breaker switch, the mechanical position sensor being a photoelectric encoder, the photoelectric encoder comprising a light source, a light code disk and a photosensitive element, the light code disk rotating shaft of the photoelectric encoder being coaxially mounted with the rotating shaft of the GIS device circuit breaker switch, the photoelectric encoder being able to convert the angular displacement on the rotating shaft of the GIS device circuit breaker switch into a pulse or digital signal through photoelectric conversion; An electrical quantity sensor for detecting the opening and closing state of the circuit breaker of the GIS device. The electrical quantity sensor is a Hall current sensor. The current signal busbar of the opening and closing coil of the high-voltage circuit breaker passes through the center of the Hall current sensor, which is used to detect the circulating current of the opening and closing coil of the GIS device; It also includes an IED device, the signal output ends of the photoelectric encoder and the Hall current sensor are connected to the signal input end of the IED device, and the sending end of the IED device is connected to the main controller.

2. The circuit breaker state mechanical characteristics online monitoring system according to claim 1, characterized in that: It also includes a density micro-water sensor for collecting gas status, which detects the micro-water content and dew point value of the SF6 gas humidity in the GIS device. The signal output end of the density micro-water sensor is connected to the signal input end of the IED device, and the sending end of the IED device is connected to the main controller.

3. The circuit breaker state mechanical characteristics online monitoring system according to claim 1, characterized in that: The IED device includes a signal conditioning circuit, a sampling chip and a single-chip microprocessor which are sequentially connected in signal. The single-chip microprocessor is connected to a main controller through a transmitting end.

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