A Regulated DC-DC Voltage Source Converter Using a High Frequency Link

1982 ◽  
Vol IA-18 (3) ◽  
pp. 279-287 ◽  
Author(s):  
V. T. Ranganathan ◽  
Phoivos D. Ziogas ◽  
Victor R. Stefanovic
Keyword(s):  
High Frequency ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dc Voltage

scholarly journals High Frequency Resonance Damping Method for Voltage Source Converter Based on Voltage Feedforward Control

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1591
Author(s):  
Bo Pang ◽  
Feng Li ◽  
Hui Dai ◽  
Heng Nian
Keyword(s):  
High Frequency ◽  
Feedforward Control ◽  
Frequency Component ◽  
Voltage Source ◽  
High Frequency Component ◽  
Voltage Source Converter ◽  
Frequency Resonance ◽  
Significant High Frequency ◽  
Resonance Damping ◽  
High Frequency Resonance

High frequency resonance (HFR) is a subsistent problem which affects the operation of the voltage source converter (VSC) connected to the parallel compensated grid. The appearance of HFR introduces a significant high frequency component in the grid voltage, thereby the operation of VSC system will be seriously affected. For enhancing the operation capability of VSC system, an HFR damping method based on the voltage feedforward control is proposed in this paper, which can reshape the VSC system impedance effectively in a wideband range. Besides, different with the existing HFR damping methods, the proposed method introduces a correction factor instead of the series virtual impedance with fixed value, so that the effect of impedance reshaping is irrelevant to the parameters of controlled object. In addition, this paper analyzes the fundamental control performance of VSC system after equipping the proposed method, for verifying that the proposed method will not worsen the fundamental control. Experimental results are given to validate the effectiveness of the proposed damping method.

scholarly journals Multiterminal Medium Voltage DC Distribution Network Hierarchical Control

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 506 ◽  
Author(s):  
Patrobers Simiyu ◽  
Ai Xin ◽  
Kunyu Wang ◽  
George Adwek ◽  
Salman Salman
Keyword(s):  
Optimal Power Flow ◽  
Distribution Network ◽  
Hierarchical Control ◽  
Active Power ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dc Voltage ◽  
Medium Voltage ◽  
Control Scheme ◽  
Medium Voltage Dc

In this research study, a multiterminal voltage source converter (VSC) medium voltage DC (MVDC) distribution network hierarchical control scheme is proposed for renewable energy (RE) integration in a co-simulation environment of MATLAB and PSCAD/EMTDC. A DC optimal power flow (DC OPF) secondary controller is created in MATLAB. In PSCAD/EMTDC, the main circuit containing the adaptive DC voltage droop with a dead band and virtual synchronous generator (VSG) based primary controller for the VSCs is implemented. The simulation of the MVDC network under the proposed hierarchical control scheme is investigated considering variations in wind and solar photovoltaic (PV) power. The network is also connected to the standard IEEE-39 bus system and the hierarchical scheme tested by assessing the effect of tripping as well as restoration of the REs. The results show that during random variations in active power such as increasing wind and PV power generation, a sudden reduction or tripping of wind and PV power, the primary controller ensures accurate active power sharing amongst the droop-based VSCs as well as regulates DC voltage deviations within the set range of 0.98–1.02 pu with an enhanced dynamic response. The DC OPF secondary control optimizes the system’s losses by 38% regularly giving optimal droop settings to the primary controllers to ensure proper active power balance and DC voltage stability. This study demonstrates that the hierarchical control strategy is effective for RE integration in the MVDC distribution network.

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

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4458 ◽  
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.

Research on DC Voltage Control Strategies for Typical Four-Terminal HVDC System

2014 ◽  
Vol 521 ◽  
pp. 222-228
Author(s):  
Kai Wang ◽  
Hai Shun Sun ◽  
Yu Hua ◽  
Yuan Liu ◽  
Wei Xing Lin ◽  
...  
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Control Strategy ◽  
Alternative Energy ◽  
Control Strategies ◽  
Future Trend ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dc Voltage ◽  
High Voltage Direct Current

The continuous development of alternative energy has put forward higher requirement for electricity transmission. To cope with its fluctuation characteristics, high voltage direct current (HVDC) technology has received more attention. Voltage Source Converter (VSC) based Multi-Terminal High Voltage Direct Current (MTDC) represents the future trend of HVDC technology. This paper mainly focuses on the control strategies of a four-terminal VSC based MTDC power transmission system. The operation characteristic of the system was studied, and the proposed two control strategies, master-slave control strategy and DC voltage droop control strategy, were verified through simulations. The latter control strategy was proved to be performing well under various conditions, including converter station disconnection and faults at AC side of the converter.

scholarly journals An Interaction Less Duo Control Strategy for Bi-polar Voltage Source Converter in Renewables Integrated Multi-Terminal HVDC (MTDC) Grids

2022 ◽  
Author(s):  
Satish Kumar Ancha
Keyword(s):  
Power System ◽  
New England ◽  
Case Studies ◽  
Control Strategy ◽  
Control Technique ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Droop Control ◽  
Dc Voltage ◽  
Test Systems

The PVF or PV<sup>2</sup>F<sup> </sup>double droop control is commended for its ability to regulate both the dc voltage and frequency in a decentralized approach. However, a convincing response is not achieved due to an interaction between the droop characteristics of dc voltage and frequency. This interaction affects the dc voltage and frequency support of the AC system surrounded Multi-Terminal HVDC (AC-MTDC) grid. To overcome this effect, a Duo control strategy is proposed in this paper, which takes advantage of a Bi-polar Voltage Source Converter (B-VSC) topology in the MTDC grid. The virtue of proposed control technique is emphasized by comparing it with the existing $ PV<sup>2</sup>F double droop control along with three case studies and two test systems. The validation of interaction less Duo control strategy is carried out on five terminal CIGRE DC grid benchmark model integrated into two area power system (AC-MTDC grid-1) and New England IEEE 39 bus system (AC-MTDC grid-2). These test systems are simulated in PSCAD/EMTDC software.

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