IEC TR 63042-303 pdf free download

IEC TR 63042-303 pdf free download.UHV AC transmission systems – Part 303: Guideline for the measurement of UHV AC transmission line power frequency parameters.
4.3 Main circuit configuration
Disconnectors at the two terminals of the transmission line should be open during measurement.
Parallel with the transmission line, connected equipment should be disconnected, such as shunt reactors and capacitive transformer.
Series reactors and capacitors used in the transmission line shall be bypassed.
If the transmission line to be measured is composed of overhead lines, cables or gasinsulated lines (GIL), it is recommended to measure the parameters of the overhead lines, cables or GIL, separately.
To eliminate the resistance of the connecting lines for test, two connecting lines, i.e. voltage and current connecting lines, can be applied. If only one connecting line is applied, the obtained line resistance should be reduced by the connecting line resistance. The measurement system should be reliably connected to the substation earthing system.
4.4 Measurement condition
Close attention should be paid to the weather condition along the line during the measurement. The measurement should be stopped if the weather is not suitable for measurement.
Before starting the measurements, check that all temporary grounding connections have been removed. No work may be done on the lines during the measurements. Make sure that this rule is followed. All local and international safety regulations shall be known and strictly observed. Safety precautions are given in Annex C.
5 Requirement of measuring instrument
5.1 Current transformer
Uncertainty of current transformer (CT) should be equal to or better than 0,5 %. It is obtained based on the method of IEC Guide 115.
5.2 Voltage transformer
Uncertainty of voltage transformer (VT) should be equal to or better than 0,5 %. It is obtained based on the method of IEC Guide 115.
5.3 Measuring Instrument of DC resistance
The instrument to measure the DC resistance of a transmission line can be a special
instrument or the combination of a DC power source, a DC voltmeter and a DC ammeter. If the DC resistance measurement meter is used, its uncertainty should be equal to or better than 0,5 %.
If the combination of a DC resistance, a DC power source, a DC voltmeter and a DC ammeter is used, the uncertainty of the DC voltmeter and ammeter should be equal to or better than 0,5 %.
5.5 Special measuring instrument of transmission line power frequency parameter The instrument should meet the requirement as follows:
• The measuring instruments at the source and ending terminals should have the function of synchronous phasor measurement and be capable of sampling single-phase and three- phase voltage and current phasors which include amplitude and phase angle of voltage and current.
• For each measurement, all the measured voltage and current phasors take a GPS PPS as a reference; phase angle of voltage or current is the difference between the measured voltage or current phasor and the reference. The magnitude of voltage or current is amplitude.
• The synchronization error of sampling between the source terminal and ending terminal should be less than 100 ns.
• The measuring instrument should be capable of eliminating signal aliasing and leakage.
• The measuring instrument should be capable of completing data analysis and calculation according to the prescribed method.
6 Conversion of offset frequency measurement results
If there are no induced voltage and induced current on the measured line at power frequency, a power frequency test power source can be directly used.
If there are induced voltage and induced current on the measured line at power frequency, an offset frequency test power source should be used to eliminate the power frequency interference. The offset frequency measurement method is usually used to measure UHV transmission line power frequency parameters. However, the parameters measured by using offset frequency method need to be converted to the parameters at power frequency.IEC TR 63042-303 pdf free download.