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HVDC system commutation failure occurrence analysis method considering phase angle jump influence

A technology of a power transmission system and a calculation method, which is applied to the conversion device of output power, the conversion of AC power input to DC power output, electrical components, etc., can solve the problems of inaccurate critical commutation voltage, etc. Improve accuracy and practicality, avoid the effect of commutation failure

Pending Publication Date: 2021-04-16
STATE GRID HUNAN ELECTRIC POWER +3
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Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a method and system for calculating the turn-off angle during the commutation process of HVDC power transmission systems in order to improve the accuracy of the turn-off angle calculation, thereby solving the problem that the critical commutation voltage is not accurate enough The problem

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  • HVDC system commutation failure occurrence analysis method considering phase angle jump influence
  • HVDC system commutation failure occurrence analysis method considering phase angle jump influence
  • HVDC system commutation failure occurrence analysis method considering phase angle jump influence

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Embodiment Construction

[0025] figure 2 The phase angle jump measurement method is implemented for the present invention. First, the normal phase is obtained by using the zero-crossing moment of the voltage and the normal angular frequency of the power grid, and then the phase difference value is obtained by subtracting the normal phase from the phase of the phase-locked loop, and it is judged whether the difference value is less than -5 / 3π, if it is less than, add 2π to the difference, if it is greater, keep the original value unchanged; then judge whether the difference is greater than 5 / 3π, if it is greater, subtract 2π from the difference, and if it is less than, keep the original value unchanged; finally Get the actual phase angle jump variable Δθ;.

[0026] image 3 This is a graph of the relationship between the turn-off angle and the effective value of the line voltage obtained by using the analysis method of the commutation failure occurrence mechanism of the HVDC system considering the i...

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Abstract

The invention discloses an HVDC system commutation failure occurrence analysis method considering phase angle jump influence. The method comprises the steps: collecting the commutation voltage of a receiving end AC bus in real time, and calculating the real-time phase of the commutation voltage in real time through a phase-locked loop; calculating the normal phase of the commutation voltage by using the zero-crossing time and the normal power grid angular frequency; subtracting the real-time phase from the normal phase to obtain a phase angle jump variable; and finally, on the basis of considering the direct current change and the phase angle jump, obtaining the relationship between the turn-off angle and the commutation voltage through the commutation process, and accurately calculating the critical commutation voltage. Thus, the problem of low calculation accuracy of the critical commutation voltage is solved to a certain extent, the accuracy and practicability of commutation failure critical voltage criteria are improved, and the method of the invention can be widely applied to an ultra-high-voltage direct-current transmission control system.

Description

technical field [0001] The invention relates to the technical field of power transmission, in particular to a method and a system for calculating a turn-off angle during a commutation process of a high-voltage direct current transmission system. Background technique [0002] The reverse distribution of primary energy and power demand in my country has made the HVDC transmission technology with long transmission distance and large capacity rapidly developed and widely used. The thyristor elements used in line-commutated-converter based high voltage direct current (LCC-HVDC) based grid commutated converters have no self-shut-off capability, and there is a greater possibility of conversion in the event of a power grid fault at the receiving end. Phase failure will cause the DC current to increase rapidly, the DC voltage to drop rapidly, the transmission power to decrease rapidly, and the DC system may be blocked when the fault is serious, which will have a serious impact on the...

Claims

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Application Information

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IPC IPC(8): H02J3/36H02M7/00H02M7/757
CPCY02E60/60
Inventor 罗安朱仁龙李军周小平武卫东洪乐荣伍咏红夏海涛陈远扬刘一锋
Owner STATE GRID HUNAN ELECTRIC POWER
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