This standard specifies the measurement method and data processing method of radio radiation interference caused by single-phase 25kV AC electrified railway overhead line. This standard is applicable to overhead lines of various power supply methods and various suspension methods. The measurement frequency range is 0.15～30MHz. GB/T 15709-1995 Measurement method of radio radiation interference of AC electrified railway overhead line GB/T15709-1995 Standard download decompression password: www.bzxz.net

ICS33.100
National Standard of the People's Republic of China
GB/T15709-1995
AC electrified railway overhead line
The measurement method of radiated radio interference from contact system of AC electrified railways
Published on September 25, 1995
Implemented on October 1, 1996
Published by the State Administration of Technical Supervision
National Standard of the People's Republic of China
AC electrified railway overhead line
The measurement method of radiated radio interference from contact system of AC electrified railways ways1 Subject content and scope of application
GB/T15709-1995
This standard specifies the measurement method and data processing method of radio radiation interference caused by single-phase 25V AC electrified railway contact network.
This standard is applicable to contact networks with various power supply methods and various suspension methods. The measurement range is 0.15~30MHz. 2 Reference standards
GB6113 Electromagnetic interference measuring instrumentwwW.bzxz.Net
3 Terms
3.1 Contact network
The overhead wire system that supplies locomotive power through the pantograph mainly includes pillars, supporting structures and contact suspension. 3.2 Contact network radio radiation interference
Under normal power supply conditions, the contact network causes radio radiation interference caused by partial discharge due to poor contact of some metal parts or due to contamination on the surface of insulating equipment.
4 Measurement method
4.1 Measuring instrument
The quasi-peak value is used for the measurement of radio radiation interference field strength value, and its technical indicators shall comply with the relevant provisions of GB6113. 4.2 Measuring antenna
4.2.1 A circular (or frame-shaped) antenna shall be used, and its technical indicators shall comply with the relevant provisions of GB6113. 4.2.2 Antenna height: The center point of the antenna shall be 1.0+m from the ground. 4.2.3 Antenna polarization: The antenna plane is perpendicular to the ground, and the antenna orientation is adjusted to maximize the meter reading. 4.3 Measurement rate
Use 1.0MHz±10% as the reference measurement rate. If necessary, other frequencies or full-segment scanning can be selected within the range of 0.15 to 30 MHz.
4.4 Measuring distance
For single-track electrified railway, the measuring antenna should be placed 10±1m away from the center line of the railway. For double-track or station yard, the measuring antenna should be placed 10±1m away from the center line of the nearest electrified railway.
4.5 Measurement conditions
4.5.1 Selection of measurement points
Approved by the State Administration of Technical Supervision on September 25, 1995 and implemented on October 1, 1996
GB/T15709-1995
Measurement is only carried out in the area where interference needs to be checked, and no full evaluation is carried out. 4.5.2 Measurement environment
The measurement site should be located in a flat area with low fill and shallow excavation. There should be no distribution lines and buildings below 10kV within 20m of the measurement point. The sensitive measurement site should be far away from power transmission lines, roads and other interference sources to ensure that the readings of these interferences on the instrument are at least 6 dB lower than the interference of the overhead line.
4.5.3 Weather conditions
Measurement should be carried out in rainless, snowless and fogless weather. 4.5.4 Power supply and operation conditions
Under normal power supply, there should be no train running within 2km before and after the measurement point. 4.6 Data reading or recording
4.6.1 Automatic recording
The recording device is connected to the output terminal of the quasi-bee value detection voltage of the interference measuring instrument. The mechanical time constant of the recording device should meet the requirements of the time constant of the electric meter in GB6113. When using a tape recorder or other electronic recording device, a filter network with an equivalent mechanical time constant of the electric meter should be installed inside or outside the interference measuring instrument.
4.6-2 Manual recording
When the measured radiation interference level fluctuation range is within ±3dB, it is allowed to collect data by manual recording method: in this case, one data is read manually every 58 or so. 4.6.3 Measurement time
The measurement time for each measurement is 2 to 5 minutes. The interval between each two measurements shall not be less than 30 minutes, and the number of measurements shall not be less than 6 times. 5 Data processing method
5.1 Method of expressing measurement results
The interference field strength measurement results are expressed in dB (pV/m). 5.2 Selection of sampling rate
The sampling rate of the recorder to record data shall not be less than 5 per second. 5.3 Statistical value of measurement data
The statistical average value is used for the measurement result.
.....(1)
In the formula, E is the statistical average value of the n-th measurement value: and——number of measurements:
E is the level value of the interference field strength that does not exceed the probability of 80% of the time, 5.4 Statistical evaluation
Uses the 80%, 80% rule. That is, for more than 80% of the time, the confidence level that the radio interference of the electrified railway overhead contact network does not exceed the allowable value is at least 80%.
Based on the given interference allowable value, the following formula is used to judge the interference level of the electrified railway overhead contact network. E+KXS.L
Where: K
is a constant that depends on n, and it can be determined by satisfying the 80%, 80% rule. The relationship between K value and is shown in the following table: 6
The sample standard deviation of # measurement results, dB (μV/m), is calculated from formula (3): 12
GB/T15709-1995
L-—Permissible value of radio interference dB (μV/m) Working conditions that need to be recorded in the measurement report 6
Measurement time and place.
Weather,
Interference measurement only, record the model, number and working status parameters of the equipment. Railway mileage, power supply mode, contact and suspension mode, pollution migration level, contact line type, single or double line, etc., measurement unit, measurement personnel.
Additional notes:
This standard is proposed by the Ministry of Railways of the People's Republic of China. This standard is under the jurisdiction of the National Radio Interference Standardization Technical Committee C Subcommittee. This standard was drafted by Northern Jiaotong University and the Communication Signal Survey and Design Institute of the Electrification Engineering Bureau of the Ministry of Railways. The main drafters of this standard are Jia Huaiyi, Zhang Linchang, Jiang Zhongyong, Zhou Kesheng, Han Fang, Jiang Shouning, Xu Xiaoyuan, and Li Xianxin. This standard is entrusted to Northern Jiaotong University and the Communication Signal Survey and Design Institute of the Electrification Engineering Bureau of the Ministry of Railways for interpretation. (3)
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.