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Simulation and analysis of a VSC-HVDC transmission system based on DC Line-Line fault

Alhaj Zber Sanabel Muhson, Al-Karakchi Ahmed A. Abdullah, Al-Jawady Noha Abed-AL-Bary, Al-Rifaie Alya Hamid

Przegląd Elektrotechniczny

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2022

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R. 98, nr 8

69--72

EN

HVDC is a well-established technique for transferring the electrical energy over long distances via overhead transmission lines. At threelevels, the HVDC systems utilizing voltage-source converters (VSCs) are such a major concern that complete displacement of the infamous system is not an option. This study invistigates the behavior of HVDC systems activated by a multi-level VSC. This investigation provides a systematic assessment of the normal state, the nature of a DC link fault in a HVDC system and through a permanent line-to-line fault.

PL

HVDC to dobrze znana technika przesyłania energii elektrycznej na duże odległości za pośrednictwem napowietrznych linii przesyłowych. Na trzech poziomach systemy HVDC wykorzystujące przetwornice napięcia (VSC) są tak poważnym problemem, że całkowite przemieszczenie niesławnego systemu nie wchodzi w grę. Niniejsze badanie bada zachowanie systemów HVDC aktywowanych przez wielopoziomowy VSC. Badanie to zapewnia systematyczną ocenę stanu normalnego, charakteru zwarcia łącza DC w systemie HVDC oraz trwałego zwarcia międzyprzewodowego.

2

VSC-HVDC transmission line fault location based on transient characteristics

Zhang Yanxia, Bi Anlu, Wang Jian, Zhang Fuhe, Lu Jingyi

Archives of Electrical Engineering

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2021

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Vol. 70, nr 2

381--398

EN

Accurate and reliable fault location is necessary for ensuring the safe and reliable operation of the VSC-HVDC transmission system. This paper proposed a single-terminal fault location method based on the fault transient characteristics of the two-terminal VSCH-VDC transmission system. The pole-to-pole transient fault process was divided into three stages, the time-domain expression of the DC current during the diode freewheel stage was used to locate the fault point, and a criterion for judging whether the fault evolves to the diode freewheel stage was proposed. Taking into account the enhancing effect of the opposite system to the fault current, the DC side pole-to-ground fault networkwas equated to a fourth-order circuit model, the relationship of fault distance with the characteristic roots of fault current differential equationwas derived, and the Prony algorithmwas utilized for datafitting to extract characteristic roots to realize fault location. A two-terminal VSC-HVDC transmission system was modelled in PSCAD/EMTDC. The simulation result verifies that the proposed principle can accurately locate the fault point on the VSC-HVDC transmission lines.

3

Overvoltage Assessment of Point-to-Point VSC-Based HVDC Systems

Jardini J. A., Vasquez-Arnez R. L., Bassini M. T., Horita M. A. B., Saiki G. Y., Cavalheiro M. R.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 8

105--112

PL

Artykuł przedstawia rezultaty symulacji przepięć występujących w sieci DC bazującej na wykorzystaniu VSC (voltage source converters). Układ VSC wykorzystuje technikę MMC (modular multi-level converter). Rozpatrzono też wpływ sąsziadującej z siecią DC sieci AC.

EN

The application of voltage source converters (VSCs) into medium- and high-power transmission is currently attracting increased attention. In view of this increased attention, this article provides the simulation results of the overvoltages produced by faults occurring in the DC line of a point-to-point VSC-based HVDC system as well as in a neighbouring AC line system. The VSC converters considered here use the MMC (modular multi-level converter) technique to generate the voltage waveform. For pole-to-ground faults occurring in the DC link of a symmetrical monopole system, significantly high overvoltages may arise on the sound pole. This condition is of concern, mainly during the planning stage of the VSC-HVDC project, as it may require the installation of surge arresters with a good performance and/or also additional insulation of the line. In addition, unless the faults occurring on the DC link are quickly removed, sustained overvoltages can threaten the normal operation of the surge arresters installed on the DC side of both sound and faulty poles. Faults and other events in the AC system (near the DC link) may lead to sustained overvoltages that should also be examined regarding the response of the surge arresters.

4

Input-Output Linearization and Predictive Current Controller for Offshore Wind Farm VSC-HVDC

Li S., Wang Z., Wang G.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1a

230--234

EN

In this paper, a nonlinear controller for VSC-HVDC transmission system is proposed. The feedback linearization based nonlinear differential-geometric techniques is used to cancel nonlinearities and decouple the input control variables. A predictive current control (PCC) method is also proposed. It can predict the current reference for the next sampling instant rapidly and accurately. Comprehensive time-domain computer simulations within MATLAB/Simulink have been carried out and the results show the feasibility and effectiveness of the proposed control scheme.

PL

W artykule przedstawiono algorytm sterowania nieliniowego dla system przesyłu energii VSC-HVDC. W celu odprzężenia sterowanych zmiennych i eliminacji nieliniowości, zastosowano technikę nieliniowej geometrii-różniczkowej do linearyzacji sprzężenia zwrotnego. Zaproponowano także sterowanie predykcyjne prądu. Wykonane badania symulacyjne w programie Matlab/Simulink potwierdziły skuteczność algorytmu sterowania.