scholarly journals Multi-Terminal DC Grid with Wind Power Injection

Wind ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 17-36
Author(s):  
Lilantha Samaranayake ◽  
Carlos E. Ugalde-Loo ◽  
Oluwole D. Adeuyi ◽  
John Licari ◽  
Janaka B. Ekanayake
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Power Injection ◽  
Power Frequency ◽  
Cross Country ◽  
Real Time Digital Simulator

With the development of offshore wind generation, the interest in cross-country connections is also increasing, which requires models to study their complex static and dynamic behaviors. This paper presents the mathematical modeling of an offshore wind farm integrated into a cross-country HVDC network forming a multi-terminal high-voltage DC (MTDC) network. The voltage source converter models were added with the control of active power, reactive power, frequency, and DC link voltages at appropriate nodes in the MTDC, resembling a typical cross-country multi-terminal type of HVDC scenario. The mathematical model for the network together with the controllers were simulated in MATLABTM and experimentally verified using a real-time digital simulator hardware setup. The resulting static and dynamic responses from the hardware setup agreed well with those from simulations of the developed models.

Simulated Onshore-Fault Ride through of Offshore Wind Farms Connected through VSC HVDC

2008 ◽  
Vol 32 (2) ◽  
pp. 103-113 ◽  
Author(s):  
A. Arulampalam ◽  
G. Ramtharan ◽  
N. Caliao ◽  
J.B. Ekanayake ◽  
N. Jenkins
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Wind Farms ◽  
Offshore Wind ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
Grid Connection ◽  
Fault Ride Through

Effective Onshore-Fault Ride Through was demonstrated by simulation for a Fixed Speed Induction Generator (FSIG) offshore wind farm connected through a Voltage Source Converter HVDC link. When a terrestrial grid fault occurs, power through the onshore converter reduces and the DC link voltage increases. A control system was then used to block the offshore converter. The offshore AC network voltage was reduced to achieve rapid power rejection. Reactive power at the onshore converter was controlled to support the AC network voltage according to the GB Grid Code requirements. Two cases, a 200 ms terrestrial fault and a 50% retained voltage fault of duration 710 ms, at the grid connection point were studied. The simulation results show that power blocking at the offshore converter was effective and the DC link voltage was controlled.

scholarly journals A Multi-Terminal HVdc Grid Topology Proposal for Offshore Wind Farms

2020 ◽  
Vol 10 (5) ◽  
pp. 1833
Author(s):  
Ali Raza ◽  
Muhammad Younis ◽  
Yuchao Liu ◽  
Ali Altalbe ◽  
Kumars Rouzbehi ◽  
...  
Keyword(s):  
High Voltage ◽  
Wind Farm ◽  
Wind Farms ◽  
Offshore Wind ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Offshore Platforms ◽  
Offshore Wind Farms ◽  
Dc Fault ◽  
Grid Side

Although various topologies of multi-terminal high voltage direct current (MT-HVdc) transmission systems are available in the literature, most of them are prone to loss of flexibility, reliability, stability, and redundancy in the events of grid contingencies. In this research, two new wind farms and substation ring topology (2WF-SSRT) are designed and proposed to address the aforementioned shortcomings. The objective of this paper is to investigate MT-HVdc grid topologies for integrating large offshore wind farms with an emphasis on power loss in the event of a dc grid fault or mainland alternating current (ac)grid abnormality. Standards and control of voltage source converter (VSC) based MT-HVdc grids are defined and discussed. High voltage dc switch-gear and dc circuit topologies are appraised based on the necessity of dc cables, HVdc circuit breakers, and extra offshore platforms. In this paper, the proposed topology is analyzed and compared with the formers for number and ratings of offshore substations, dc breakers, ultra-fast mechanical actuators, dc circuits, cost, flexibility, utilization, and redundancy of HVdc links. Coordinated operation of various topologies is assessed and compared with respect to the designed control scheme via a developed EMTDC/PSCAD simulation platform considering three fault scenarios: dc fault on transmission link connecting the wind farm to mainland power converters, dc fault within substation ring of VSC-HVdc stations, and ultimate disconnection of grid side VSC station. Results show that 2WF-SSRT is a promising topology for future MT-HVdc grids.

scholarly journals Active Power Filtering Embedded in the Frequency Control of an Offshore Wind Farm Connected to a Diode-Rectifier-Based HVDC Link

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2718 ◽  
Author(s):  
Ashkan Nami ◽  
José Amenedo ◽  
Santiago Gómez ◽  
Miguel Álvarez
Keyword(s):  
Wind Farm ◽  
Frequency Control ◽  
Harmonic Distortion ◽  
Active Power ◽  
Offshore Wind ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Offshore Wind Farm ◽  
Harmonic Compensation ◽  
Dynamic Phasor

This paper presents a novel active power filtering (APF) scheme embedded in a centralised frequency control of an offshore wind farm (OWF) connected to a high voltage direct current link through a diode rectifier station. The APF is carried out by a voltage source converter (VSC), which is connected to the rectifier station to provide frequency control for the offshore ac-grid. The proposed APF scheme eliminates harmonic currents at a capacitor bank placed at the rectifier station. This leads to a significant reduction in the total harmonic distortion of the offshore ac-grid voltage, and thus, to an improvement in the OWF power. Hence, the rectifier passive ac-filter bank is not needed anymore. A new selective harmonic compensation method based on the dynamic phasor (DP) theory is used in the proposed APF scheme which allows the extraction of the phasor form of harmonics in dc-signals. Therefore, the well-known proportional-integral regulators are used for the harmonic current compensation. Moreover, the offshore ac-grid is modelled for the system harmonic analysis using a grid solution based on the DP theory. Finally, a VSC power rating analysis is studied. The performance of the proposal is validated by simulations in both steady-state and transient conditions.

scholarly journals The Influence of VSC–HVDC Reactive Power Control Mode on AC Power System Stability

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1677 ◽  
Author(s):  
Ying Wang ◽  
Youbin Zhou ◽  
Dahu Li ◽  
Dejun Shao ◽  
Kan Cao ◽  
...  
Keyword(s):  
Power System ◽  
Power Control ◽  
Reactive Power ◽  
Dynamic Responses ◽  
System Stability ◽  
Control Mode ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Reactive Power Control ◽  
Margin Control

Voltage source converter-based high-voltage direct current (VSC-HVDC) has the advantage of fast and independent controllability on active and reactive power. This paper focuses on effects of commonly proposed reactive power control modes, constant reactive power control and AC voltage margin control. Based on the mathematical model of single machine infinity equivalent system with embedded VSC-HVDC, the influence of VSC-HVDC with different reactive power control strategies on transient stability and dynamic stability of the AC system is studied. Then case studies were conducted with a realistic model of grid. The dynamic responses of AC/DC systems for different VSC-HVDC reactive power control modes were compared in detail. It is shown that compared to constant reactive power control, AC voltage margin control can provide voltage support to enhance the transient angle stability of an AC system. However, the fluctuant reactive power injected into a weak AC system may adversely affect power system oscillation damping for VSC-HVDC with AC voltage margin control, if the parameters of the controller have not been optimized to suppress the low-frequency oscillation. The results of this paper can provide certain reference for the decision of an appropriate VSC-HVDC reactive power control mode in practice.

Modeling and Simulation of Modular Multilevel Converter Based-HVDC Connecting to Offshore Wind Farms

2014 ◽  
Vol 905 ◽  
pp. 421-426 ◽  
Author(s):  
Seung Hyun Kim ◽  
Woo Cheol Jeong ◽  
Eel Hwan Kim
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Control Method ◽  
Wind Farms ◽  
Offshore Wind ◽  
Voltage Source ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Offshore Wind Farms ◽  
Hvdc System

Modular multilevel Converter (MMC) is a new type of voltage source converter (VSC) topology. The use of this converter in a high-voltage direct current (HVDC) system is called by a MMC-HVDC system. The MMC-HVDC has the advantage in terms of scalability, performance, and efficiency over two-and three-level VSC-HVDC. In this paper, the MMC-HVDC system is used to connect between main grid in Jeju Island and virtual offshore wind farms. The aim is to transfer the power from offshore wind farm to the main grid and to compensate reactive power for the main grid. The simulation is carried out by using PSCAD/EMTDC program, and the results will confirm the effectiveness of the proposed control method.

An Adaptive Coordinated Control for an Offshore Wind Farm Connected VSC Based Multi-Terminal DC Transmission System

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
M. Ajay Kumar ◽  
N.V. Srikanth
Keyword(s):  
Wind Farm ◽  
Control Design ◽  
Wind Farms ◽  
Coordinated Control ◽  
Transmission System ◽  
Offshore Wind ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Offshore Wind Farm ◽  
Inference System

AbstractThe voltage source converter (VSC) based multiterminal high voltage direct current (MTDC) transmission system is an interesting technical option to integrate offshore wind farms with the onshore grid due to its unique performance characteristics and reduced power loss via extruded DC cables. In order to enhance the reliability and stability of the MTDC system, an adaptive neuro fuzzy inference system (ANFIS) based coordinated control design has been addressed in this paper. A four terminal VSC-MTDC system which consists of an offshore wind farm and oil platform is implemented in MATLAB/ SimPowerSystems software. The proposed model is tested under different fault scenarios along with the converter outage and simulation results show that the novel coordinated control design has great dynamic stabilities and also the VSC-MTDC system can supply AC voltage of good quality to offshore loads during the disturbances.

scholarly journals Stabilization of Wind Generator by Using STATCOM/SMES

2009 ◽  
Vol 1 (3) ◽  
pp. 528-538
Author(s):  
M. R. I. Sheikh ◽  
S. M. A. Razzak
Keyword(s):  
Energy Storage ◽  
Wind Speed ◽  
Output Power ◽  
Wind Farm ◽  
Reactive Power ◽  
Moving Average ◽  
Voltage Source ◽  
Storage Device ◽  
Voltage Source Converter ◽  
Wind Generator

In this work, the STATCOM/SMES system with a voltage-source IGBT converter is modeled as a controllable energy source. The objective of the proposed STATCOM/SMES topology is to provide both active and reactive power, which can significantly decrease the voltage and power fluctuations of grid connected fixed speed wind generators. One major problem in wind generator output power smoothing is setting of the reference output power. Constant output power reference is not a good choice because there can be some cases where wind speed is very low and then sufficient power cannot be obtained. In that case, energy storage device can solve the problem but large energy capacity may be needed. To generate output power reference, a Simple Moving Average (SMA) technique is used which corresponds to the energy storage capacity. Thus the capacity of SMES can be small (50% of wind farm capacity). Real wind speed data is used in the simulation analyses, which validates the effectiveness of the proposed control strategy. Keywords: STATCOM/SMES; Energy storage system (ESS); Simple moving average (SMA); Fixed speed wind generator; Voltage source converter (VSC).© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i3.2605         J. Sci. Res. 1 (3), 528-538 (2009)

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