Multi Point Voltage Control for DFIG wind farms in VSC-MTDC Network

Abstract The development of voltage source converter (VSC) based multi-terminal HVDC network (VSC-MTDC) is emerging as the most adaptive approach to managing high penetration of wind energy in long distance.However, MTDC networks depend on highly controllable devices, which may permit not only transporting power, but also assuring secure and stable operation for AC grids. This paper first presents an overview of different control schemes for VSCs in VSC-MTDC network, then proposes a modification scheme of multi-point DC voltage control for wind farms equipped with doubly fed induction generators (DFIG). Finally, the proposed strategy is verified on PSCAD/EMTDC software, and simulation results show that the state of constant power control and constant DC voltage control can be automatically conversed, thus guarantee the stability of DC voltage and the transmission reliability after the power variation in DFIG wind farms and the operation fault at converter stations.

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Modeling and Analyzing the Effect of Frequency Variation on Weak Grid-Connected VSC System Stability in DC Voltage Control Timescale

Energies ◽

10.3390/en12234458 ◽

2019 ◽

Vol 12 (23) ◽

pp. 4458 ◽

Cited By ~ 3

Author(s):

Yang ◽

Yuan

Keyword(s):

Voltage Control ◽

System Stability ◽

Voltage Source ◽

Frequency Variation ◽

Voltage Source Converter ◽

Small Signal ◽

Small Signal Stability ◽

Dc Voltage ◽

Weak Grid ◽

Dc Voltage Control

The effect of frequency variation on system stability becomes crucial when a voltage source converter (VSC) is connected to a weak grid. However, previous studies lack enough mechanism cognitions of this effect, especially on the stability issues in DC voltage control (DVC) timescale (around 100 ms). Hence, this paper presented a thorough analysis of the effect mechanism of frequency variation on the weak grid-connected VSC system stability in a DVC timescale. Firstly, based on instantaneous power theory, a novel method in which the active/reactive powers are calculated with the time-varying frequency of voltage vectors was proposed. This method could intuitively reflect the effect of frequency variation on the active/reactive powers and could also help reduce the system order to a certain extent. Then, a small-signal model was established based on the motion equation concept, to depict the effect of frequency variation on the weak grid-connected VSC system dynamics. Furthermore, an analytical method was utilized to quantify the effect of frequency variation on the system’s small-signal stability. The quantitative analysis considered the interactions between the DC voltage control, the terminal voltage control, phase-locked loop, and the power network. Finally, case studies were conducted, and simulation results supported the analytical analyses.

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Implementation of DC voltage controllers on enhancing the stability of multi-terminal DC grids

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v11i3.pp1894-1904 ◽

2021 ◽

Vol 11 (3) ◽

pp. 1894

Author(s):

Moussa Belgacem ◽

Mohamed Khatir ◽

Mohammed Abdeldjalil Djehaf ◽

Sid Ahmed Zidi ◽

Riyadh Bouddou

Keyword(s):

Control Strategies ◽

Voltage Control ◽

Wind Farms ◽

Voltage Regulation ◽

Green Energy ◽

Offshore Wind ◽

Dc Voltage ◽

Dc Voltage Control ◽

Simulation Results ◽

The Stability

Because of the increasing penetration of intermittent green energy resources like offshore wind farms, solar photovoltaic, the multi-terminal DC grid using VSC technology is considered a promising solution for interconnecting these future energies. To improve the stability of the multi-terminal direct current (MTDC) network, DC voltage control strategies based on voltage margin and voltage droop technique have been developed and investigated in this article. These two control strategies are implemented in the proposed model, a ±400 kV meshed multi-terminal MTDC network based on VSC technology with four terminals during the outage converter. The simulation results include the comparison and analysis of both techniques under the outage converter equipped with constant DC voltage control, then the outage converter equipped with constant active power control. The simulation results confirm that the DC voltage droop technique has a better dynamic performance of power sharing and DC voltage regulation.

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DC Terminal Impedance Model of Voltage Source Converter With DC Voltage Control

2018 IEEE International Power Electronics and Application Conference and Exposition (PEAC) ◽

10.1109/peac.2018.8590458 ◽

2018 ◽

Cited By ~ 2

Author(s):

Danhong Xue ◽

Jinjun Liu ◽

Zeng Liu

Keyword(s):

Voltage Control ◽

Voltage Source ◽

Voltage Source Converter ◽

Dc Voltage ◽

Impedance Model ◽

Dc Voltage Control

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Application of Multipoint DC Voltage Control in VSC-MTDC System

Journal of Electrical and Computer Engineering ◽

10.1155/2013/257387 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Yang Xi ◽

Ai Qian ◽

Huang Jiantao ◽

An Yiran

Keyword(s):

Control Strategy ◽

Wind Farm ◽

Power Transmission ◽

Voltage Control ◽

Stability Control ◽

Control Mode ◽

Voltage Source ◽

Voltage Control Strategy ◽

Dc Voltage ◽

Dc Voltage Control

The voltage-source-converter- (VSC-) based multiterminal VSC-HVDC power transmission system (VSC-MTDC) is an ideal approach to connect wind farm with power grid. Analyzing the characteristics of doubly fed induction generators as well as the basic principle and the control strategy of VSC-MTDC, a multiterminal DC voltage control strategy suitable for wind farm connected with VSC-MTDC is proposed. By use of PSCAD/EMTDC, the proposed control strategy is simulated, and simulation results show that using the proposed control strategy the conversion between constant power control mode and constant DC voltage control mode can be automatically implemented; thus the DC voltage stability control and reliable power output of wind farm can be ensured after the fault-caused outage of converter station controlled by constant DC voltage and under other faults. The simulation result shows that the model can fulfill multiterminal power transmission and fast response control.

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