CN103207309B - Voltage measurement method of inter-phase short-circuit fault point of UHV (ultra-high voltage) AC (alternating current) power transmission line - Google Patents

Abstract

The invention discloses a voltage measurement method of an inter-phase short-circuit fault point of a UHV AC power transmission line. The voltage measurement method of the inter-phase short-circuit fault point of the UHV AC power transmission line is characterized by utilizing a long line equation to describe physical characteristics of voltage and current transmission of the UHV AC power transmission line; utilizing the phase angle of fault inter-phase negative-sequence current of protection installation location of the UHV AC power transmission line to estimate a voltage phase angle of the inter-phase short-circuit fault point of the UHV AC power transmission line; and computing the voltage of inter-phase short-circuit fault point of the UHV AC power transmission line according to a hyperbolic tangent function relationship between the voltage drop along the line and the fault distance of the UHV AC power transmission line. The measurement result is not affected by the distributed capacitance, the transition resistance, the fault location and the load current, so that the measurement accuracy is high.

Description

Ultrahigh voltage alternating current transmission lines phase fault point voltage measuring method

Technical field

The present invention relates to Relay Protection Technology in Power System field, specifically relate to a kind of ultrahigh voltage alternating current transmission lines phase fault point voltage measuring method.

Background technology

By the real-time measurement to ultrahigh voltage alternating current transmission lines phase fault point voltage, what be conducive to grasping in time phase fault thermally-stabilised and Dynamic stability on ultrahigh voltage alternating current transmission lines affects situation, for guaranteeing that ultrahigh voltage alternating current transmission lines safety and the stabilization of power grids provide reliable decision-making foundation.By the real-time measurement to ultrahigh voltage alternating current transmission lines phase fault point voltage, can diagnose the low middle high resistance phase fault type of ultrahigh voltage alternating current transmission lines according to phase fault point voltage amplitude size cases, for ultrahigh voltage alternating current transmission lines fault line walking improves reference frame, win the quality time for fixing a breakdown and restoring electricity.

But; current technical field of relay protection not yet proposes a kind of measuring method of energy accurate Calculation ultrahigh voltage alternating current transmission lines phase fault point voltage; cannot in order to grasp in time, phase fault be thermally-stabilised on ultrahigh voltage alternating current transmission lines, the situation that affects of Dynamic stability provides reliable decision-making foundation, also cannot carry out diagnosis to the low middle high resistance phase fault type of ultrahigh voltage alternating current transmission lines provides scientific basis.

Summary of the invention

The object of the invention is to the deficiency overcoming prior art existence, a kind of ultrahigh voltage alternating current transmission lines phase fault point voltage measuring method is provided.

Ultrahigh voltage alternating current transmission lines phase fault point voltage measuring method, its main points are, comprise the steps:

(1) provide a kind of protective device, it includes the data acquisition system (DAS) and data handling system that are connected, and wherein data acquisition system (DAS) measures the fault voltage between phases of ultrahigh voltage alternating current transmission lines protection installation place fault three-phase current and negative-sequence current between fault phase wherein, φ φ=AB, BC, CA are alternate;

(2) data acquisition system (DAS) of protective device measured ultrahigh voltage alternating current transmission lines protection installation place fault phase between electric parameters send the data handling system of protective device to, the data handling system of protective device utilizes ultrahigh voltage alternating current transmission lines to protect electric parameters between the fault phase of installation place to calculate ultrahigh voltage alternating current transmission lines phase fault point voltage

${\stackrel{\·}{U}}_f=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ\φ}}\right)\sin (\mathrm{\β}+\mathrm{\θ})-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ\φ}}\right)\cos (\mathrm{\β}+\mathrm{\θ})}{\cos \mathrm{\α}\sin (\mathrm{\β}+\mathrm{\θ})-\cos (\mathrm{\β}+\mathrm{\θ})\sin \mathrm{\α}}(\cos \mathrm{\α}+j\sin \mathrm{\α})$

Wherein, φ φ=AB, BC, CA phase; l _setfor protection seting scope; β=Arg (Z _c1th (γ ₁l _set)); for fault voltage between phases; for fault three-phase current; for negative-sequence current between fault phase; γ ₁for ultrahigh voltage alternating current transmission lines positive sequence propagation coefficient; Zc1 is ultrahigh voltage alternating current transmission lines positive sequence wave impedance; for real part; for imaginary part; Th (.) is hyperbolic tangent function.

Feature of the present invention and technological achievement:

The inventive method adopts long-line equation to describe ultrahigh voltage alternating current transmission lines voltage, the physical characteristics of current delivery, ultrahigh voltage alternating current transmission lines is utilized to protect the phase angle of negative-sequence current between the fault phase of installation place to estimate the phase angle of ultrahigh voltage alternating current transmission lines phase fault point voltage, be that hyperbolic tangent function relation calculates ultrahigh voltage alternating current transmission lines phase fault point voltage according to ultrahigh voltage alternating current transmission lines voltage-drop along the line and fault distance, measurement result is not by distributed capacitance, transition resistance, the impact of abort situation and load current, there is very high measuring accuracy.

Accompanying drawing explanation

Fig. 1 is the transmission system schematic diagram applying ultrahigh voltage alternating current transmission lines of the present invention.

Embodiment

According to Figure of description, technical scheme of the present invention is expressed in further detail below.

Fig. 1 is the transmission system schematic diagram applying ultrahigh voltage alternating current transmission lines of the present invention.After ultrahigh voltage alternating current transmission lines generation phase fault, the data acquisition system (DAS) of protective device measures the fault voltage between phases of ultrahigh voltage alternating current transmission lines protection installation place fault three-phase current and negative-sequence current between fault phase wherein, φ φ=AB, BC, CA phase.

The data acquisition system (DAS) of protective device is measured ultrahigh voltage alternating current transmission lines and protects electric parameters between the fault phase of installation place to send the data handling system of protective device to.

The data handling system of protective device utilizes ultrahigh voltage alternating current transmission lines to protect electric parameters between the fault phase of installation place to calculate ultrahigh voltage alternating current transmission lines phase fault point voltage

${\stackrel{\·}{U}}_f=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ\φ}}\right)\sin (\mathrm{\β}+\mathrm{\θ})-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ\φ}}\right)\cos (\mathrm{\β}+\mathrm{\θ})}{\cos \mathrm{\α}\sin (\mathrm{\β}+\mathrm{\θ})-\cos (\mathrm{\β}+\mathrm{\θ})\sin \mathrm{\α}}(\cos \mathrm{\α}+j\sin \mathrm{\α})$

Wherein, φ φ=AB, BC, CA phase; l _setfor protection seting scope; β=Arg (Z _c1th (γ ₁l _set)); for fault voltage between phases; for fault three-phase current; for negative-sequence current between fault phase; γ ₁for ultrahigh voltage alternating current transmission lines positive sequence propagation coefficient; Z _c1for ultrahigh voltage alternating current transmission lines positive sequence wave impedance; for real part; for imaginary part; Th (.) is hyperbolic tangent function.

The inventive method adopts long-line equation to describe ultrahigh voltage alternating current transmission lines voltage, the physical characteristics of current delivery, ultrahigh voltage alternating current transmission lines is utilized to protect the phase angle of negative-sequence current between the fault phase of installation place to estimate the phase angle of ultrahigh voltage alternating current transmission lines phase fault point voltage, be that hyperbolic tangent function relation calculates ultrahigh voltage alternating current transmission lines phase fault point voltage according to ultrahigh voltage alternating current transmission lines voltage-drop along the line and fault distance, measurement result is not by distributed capacitance, transition resistance, the impact of abort situation and load current, there is very high measuring accuracy.

The foregoing is only preferred embodiment of the present invention; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses, the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.

Claims (1)

1. ultrahigh voltage alternating current transmission lines phase fault point voltage measuring method, is characterized in that, comprise the steps:

(1) provide a kind of protective device, it includes the data acquisition system (DAS) and data handling system that are connected, and wherein data acquisition system (DAS) measures the fault voltage between phases of ultrahigh voltage alternating current transmission lines protection installation place fault three-phase current and negative-sequence current between fault phase wherein, φ φ=AB, BC, CA phase;

(2) data acquisition system (DAS) of protective device measured ultrahigh voltage alternating current transmission lines protection installation place fault phase between electric parameters send the data handling system of protective device to, the data handling system of protective device utilizes ultrahigh voltage alternating current transmission lines to protect electric parameters between the fault phase of installation place to calculate ultrahigh voltage alternating current transmission lines phase fault point voltage

${\stackrel{\·}{U}}_f=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ\φ}}\right)\sin (\mathrm{\β}+\mathrm{\θ})-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ\φ}}\right)\cos (\mathrm{\β}+\mathrm{\θ})}{\cos \mathrm{\α}\sin (\mathrm{\β}+\mathrm{\θ})-\cos (\mathrm{\β}+\mathrm{\θ})\sin \mathrm{\α}}(\cos \mathrm{\α}+j\sin \mathrm{\α})$

Wherein, φ φ=AB, BC, CA phase; l _setfor protection seting scope; β=Arg (Z _c1th (γ ₁l _set)); for fault voltage between phases; for fault three-phase current; for negative-sequence current between fault phase; γ ₁for ultrahigh voltage alternating current transmission lines positive sequence propagation coefficient; Z _c1for ultrahigh voltage alternating current transmission lines positive sequence wave impedance; for real part; for imaginary part; Th (.) is hyperbolic tangent function.