System composition:

The system equipment is deployed in two layers, namely the front-end lightning arrester monitoring device and the back-end lightning arrester monitoring management device.

The lightning arrester monitoring device is deployed near the lower part of the lightning arrester body to complete signal acquisition, processing, and calculation. At the same time, real-time monitoring data and transient waveform data recorded during the action of the lightning arrester are uploaded to the back-end monitoring management device through a communication interface.

The lightning arrester monitoring and management device is deployed in the electrical cabinet of the carriage, completing the collection, caching, analysis, evaluation, and primary diagnosis of monitoring data. The alarm information, status evaluation information, and real-time monitoring data output by the monitoring and management device are displayed on the built-in display screen, providing technical support for vehicle operation and maintenance personnel.

All cached data and analysis result data of the monitoring and management device can be backed up through the USB interface of the device, achieving big data accumulation and trend analysis of operating status.

System functions:

Real time monitoring of operational data

The lightning arrester monitoring system collects the following parameters every minute:

2. Transient process recording and analysis of actions

The system automatically records the waveform data of the network voltage (sampling rate of 200KSPS), impulse current (sampling rate of 4MSPS), and full current (sampling rate of 200KSPS) before and after the action of the lightning arrester (20ms before and 20ms after the action). When conducting cause analysis after an accident, the system provides recorded waveforms and network voltage analysis data (including voltage frequency, peak value, 1-20th harmonic voltage values, and total harmonic distortion THD value) to support manual analysis.

3 Risk Warning

Based on the operating parameters of lightning arresters, threshold comparison method and trend analysis method are used to evaluate the current operating risks of lightning arresters and output warning information, so as to detect and solve safety hazards of lightning arresters early and prevent operational accidents from occurring.

4. Evaluation of operating status

Comprehensively analyze the operating characteristic parameter values of lightning arresters (full current, resistive current, resistance to capacitance ratio), environmental parameters (temperature, humidity), refer to relevant specifications of the State Grid, and combine our company's experience in the maintenance process of lightning arresters to conduct real-time evaluation of the operating status of lightning arresters. The evaluation of the operation status of lightning arresters is divided into four levels: normal, attentive, abnormal, and severe.

5 Primary Fault Diagnosis

When warning information appears, combined with status evaluation information, the primary fault diagnosis module provides biased diagnostic opinions and suggested focus points. Due to the lack of online monitoring data accumulation and sample data of faulty lightning arresters, as well as the absence of mature diagnostic models in the industry, this system establishes a primary diagnostic model by mining lightning arrester maintenance data and combining it with industry standards. Under the condition of limited fault samples during the initial operation of the system, the primary diagnostic model has certain guiding significance for the maintenance of lightning arresters; After the later model is perfected, the diagnostic results can guide the maintenance of lightning arresters and achieve the goal of intelligent operation and maintenance.

System technical indicators:

Full current measurement range: 0.1-50mA

Full current measurement error: ± (Rd * 2%+5uA)

Measurement range of resistive current: 0.01-10mA

Measurement error of resistive current: ± (Rd * 3%+5uA)

Capacitive current measurement range: 0-50mA

Measurement error of capacitive current: ± (Rd * 2%+10uA)

Resistance capacitance ratio measurement range: 0.01-0.5

Measurement error of resistance capacitance ratio: ± (Rd * 2%+0.01)

The counting range for the number of lightning arrester actions is from 0 to 40000000

Error in the number of lightning arrester actions: ± (Rd × 3%)

Frequency measurement range: 45-65Hz

Frequency measurement error: ± 0.002Hz

Voltage measurement range: 0-270V (measurement range can be expanded according to actual situation)

Voltage measurement error: ± (standard reading x 0.5%)

Harmonic voltage measurement: 1-20th harmonics

Harmonic voltage measurement error: ± (standard reading x 3%)

Temperature measurement range: -40 ℃ to+100 ℃

Temperature measurement error: ± 1 ℃

Humidity measurement range: 5~95% RH

Humidity measurement error: ± 5% RH

Performance indicators of monitoring devices

● Insulation performance

Under normal test atmospheric conditions, measure the insulation resistance with a 500V megohmmeter, and the test results meet the following requirements:

a) The insulation resistance of the power supply to ground shall not be less than 100M Ω.

b) The insulation resistance of the PT secondary voltage input circuit to ground shall not be less than 100M Ω.

c) The insulation resistance between live circuits without electrical connection shall not be less than 100 M Ω.

dielectric strength

The withstand frequency is 50Hz ± 5Hz and the AC sine wave test values listed in the table below are tested for 1 minute without insulation breakdown or flashover.

● Electromagnetic compatibility capability

GB/T 17626.2-2006 Electrostatic Discharge Immunity Test Level 4, Performance A

GB/T 17626.3-2006 Radio Frequency Electromagnetic Field Radiation Immunity Test Level 3, Performance A

GB/T 17626.4-2008 Electrical Fast Transient Pulse Group Immunity Test Level 4, Performance A

GB/T 17626.5-2008 Surge (Impact) Immunity Test Level 4, Performance A

GB/T 17626.6-2008 Conducted Disturbance Immunity Test for Radio Frequency Field Induction Test Level 3, Performance A

GB/T 17626.8-2006 Power Frequency Magnetic Field Immunity Test Level 5, Performance A

GB/T 17626.9-1998 Pulse Magnetic Field Immunity Test Level 5, Performance A

GB/T 17626.10-1998 Damping oscillation magnetic field immunity test level 5, performance A

GB/T 17626.11-2008 Voltage sag, short interruption and voltage variation immunity test

Voltage sag test: 40% UT, 0.2s 70% UT, 0.5s 80% UT, 5s short interruption: 0% UT, 0.5s Performance A

Technical conditions for the use of monitoring devices

Roof monitoring device:

Working environment temperature: -40 ℃~+70 ℃;

Storage environment temperature: -40 ℃~+70 ℃;

Relative humidity: 0~100%;

Atmospheric pressure: (70-110) kPa;

Power supply: rated DC110V, range of variation DC78V - DC138V

Power supply: 20W

Protection level: IP67

Car monitoring and management device:

Working environment temperature: -20 ℃~+55 ℃

Storage environment temperature: -40 ℃~+70 ℃;

Relative humidity: 5-90%;

Atmospheric pressure: (70-110) kPa;

Power supply: rated DC110V, range of variation DC78V - DC138V;

Power supply:<60W

Protection level: IP54

系统功能实现：

避雷器运行状态在线监测系统车载监测管理装置自带7寸触摸显示屏，面向随车工程师输出监测数据、状态评价结果和诊断结果，并以不同的颜色区分预警严重等级、状态评价结果，诊断提示信息。

此外，系统提供web登录浏览模式。当监测系统发出异常提示信息时，专业级工程师可通过web登录访问实时监测数据、监测数据查询、监测数据分析，同时也可以通过配置，优化预警定值、状态评价和故障诊断模型。