Zero-sequence parameter measuring method for ultrahigh-voltage transmission line with four-circuit alternating current on one tower and double-circuit double-electrode direct current

Abstract

The invention relates to a zero-sequence parameter measuring method for an ultrahigh-voltage transmission line with a four-circuit alternating current on one tower and a double-circuit double-electrode direct current. By setting up an ultrahigh-voltage transmission line model with the four-circuit alternating current on one tower and the double-circuit double-electrode direct current based on distribution parameters, the zero-sequence voltages and the zero-sequence currents at the head end and the tail end of an ultrahigh-voltage transmission line with the four-circuit alternating current on one tower and the double-circuit double-electrode direct current are simultaneously measured through the GPS, and therefore the zero-sequence voltages and the zero-sequence currents can be synchronously sampled; then, parameters such as zero-sequence resistance, zero-sequence inductance and zero-sequence capacitance of the ultrahigh-voltage transmission line with the four-circuit alternating current on one tower and the double-circuit double-electrode direct current are obtained through the measuring and calculating method. According to the method, by means of the model based on the distribution parameters and a transmission line equation, measuring accuracy is greatly improved, and the method can meet the requirement of actual engineering measurement.

Description

technical field [0001] The invention relates to an accurate measurement method for zero-sequence parameters, which relates to an accurate measurement method for zero-sequence power frequency parameters of an ultra-high voltage four-circuit AC on the same tower / bipolar double-circuit direct current transmission line on the same tower. Background technique [0002] Transmission lines are one of the important components of the power system and play an important role in the transmission of electric energy. Transmission line parameters are the basic data for power system power flow calculation, short circuit calculation, relay protection setting and fault analysis. Accurately obtaining the parameters of the transmission line is very important to ensure the correct action of the power device and the normal operation of the power system. [0003] The zero-sequence parameters of the transmission line are affected by factors such as the geometric shape of the transmission line, curr...

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Problems solved by technology

[0006] The present invention mainly solves the disadvantages existing in the prior art that cannot be used for long-distance (300km and above) transmission line parameter measurement due to the use of concentrated parameters and ignores distributed capacitance, and also avoids excessive measurement errors caused by oversimplified parameters in previous measurement methods. The technical problem of major defects; provides a measurement not only suitable for ultra-high voltage short-distance zero-sequence parameters, but also for long-distance transmission line ze

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