Method and device for determining steady-state voltage extreme value of half-wavelength line

Abstract

The invention discloses a method and device for determining a steady-state voltage extreme value of a half-wavelength line. The method comprises: a steady-state distribution parameter model, considering an equivalent source impedance, of a half-wavelength transmission line is established and an influence on the line steady-state voltage distribution by the equivalent source impedance is analyzed;according to the steady-state distribution parameter model of the half-wavelength transmission line, voltage distribution on the steady state condition of the line and a voltage extreme value positionare obtained to obtain a voltage extreme value; and according to steady-state voltage distribution under different loads and different power factors as well as the voltage extreme value and position,an output result is outputted. According to the method disclosed by the invention, the method is used simply; the computing load is low; and the practicability is high. The method and device are applied to steady-state operation and control of the actual half-wavelength line to assist the line operation staff in managing the line effectively and safely, so that the safety and reliability of the line are improved.

Description

technical field [0001] The invention relates to the technical field of power systems, in particular to a method and system for determining the extreme value of the steady-state voltage of a half-wavelength line. Background technique [0002] The half-wavelength AC transmission method refers to the ultra-long-distance three-phase AC transmission method in which the distance of the transmission line is close to a power frequency half-wave, that is, 3000 kilometers (50Hz) or 2500 kilometers (60Hz). When the lossless half-wavelength AC transmission line is connected to the infinite system, it will have the following good characteristics: (1) The voltage at the head end and the end of the line are equal in magnitude and opposite in direction, which is equivalent to a transformer with a transformation ratio of -1. (2) Ideally, the reactive power emitted by the half-wavelength line capacitance will be consumed by the inductance of the line itself, and the line itself will not absor...

AI Technical Summary

Problems solved by technology

(2) Ideally, the reactive power emitted by the half-wavelength line capacitance will be consumed by the inductance of the line itself, and the line itself will not absorb or emit reactive power to the outside world.

[0005] Now researches have analyzed the ideal half-wavelength line steady-state voltage extremum and its position, but in the actual line, due to the influence of the reactance of the power supply and UHV transformer (called the equivalent source impedance), In particular, the reactance of UHV transformers occupies a large proportion of the total impedance of the line, and the actual electrical length of the half-wavelength line increases, so that it will not be exactly half-wavelength

Images