Browsing NTNU Open by Author "Amin, Mohammad"
Now showing items 1-14 of 14
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A Gray-Box Method for Stability and Controller Parameter Estimation in HVDC-Connected Wind Farms Based on Nonparametric Impedance
Amin, Mohammad; Molinas Cabrera, Maria Marta (Journal article; Peer reviewed, 2019)Estimation of critical control parameters is a desirable tool feature for stability analysis and impedance shaping of high voltage dc (HVdc) connected wind farms. Accurate estimation of such parameters would be enabled by ... -
Apparent impedance analysis: A new method for power system stability analysis
Rygg, Atle; Amin, Mohammad; Molinas Cabrera, Maria Marta; Gustavsen, Bjørn Alfred (Conference object; Peer reviewed, 2016)In this paper a new method for power system stability analysis is introduced. The method is based on injection of a small voltage or current in an arbitrary point of the system. The apparent impedance is defined as the ... -
Impact of power flow direction on the stability of VSC-HVDC seen from the impedance nyquist plot
Amin, Mohammad; Molinas Cabrera, Maria Marta; Lyu, Jing; Cai, Xu (Journal article, 2017)The high-voltage dc (HVDC) systems are appearing more and more, and it is becoming a requirement that the HVDC voltage-source converters (VSCs) operate both as an inverter and a rectifier without changing the controls to ... -
Impact of Power Flow Direction on the Stability of VSC-HVDC Seen from the Impedances Nyquist Plot
Amin, Mohammad; Molinas Cabrera, Maria Marta; Lyu, Jing; Cai, Xu (Journal article; Peer reviewed, 2016)The high-voltage dc (HVDC) systems are appearing more and more, and it is becoming a requirement that the HVDC voltage-source converters (VSCs) operate both as an inverter and a rectifier without changing the controls to ... -
Impedance Modeling and Stability Analysis of Grid-tied Universal Droop Control Inverter
Amin, Mohammad; Zhong, Qing-Chang (Chapter; Peer reviewed, 2019)This paper presents an impedance modeling and small-signal stability analysis of the grid-tied Universal Droop Control (UDC) inverter. The -impedance model of the UDC inverter is derived analytically and, which is verified ... -
Impedance-Based Stability Evaluation of Virtual Synchronous Machine Implementations in Converter Controllers
Unamuno, Eneko; Rygg, Atle; Amin, Mohammad; Molinas Cabrera, Maria Marta; Barrena, Jon Andoni (Chapter, 2018)This paper presents a stability evaluation of two Virtual Synchronous Machine (VSM) implementations in the control of Voltage Source Converters (VSCs): a current-controlled (CCVSM) and a voltage-controlled (VCVSM) version ... -
Instantaneous frequency tracking of harmonic distortions for grid impedance identification based on Kalman filtering
Broen, Anders Kjeka; Amin, Mohammad; Skjong, Espen; Molinas Cabrera, Maria Marta (Chapter, 2016)This paper presents a non-invasive approach for real-time grid impedance identification based on the principle of instantaneous frequency tracking of voltage and current harmonics already present in the system, by the use ... -
Methods for Identification of Instantaneous Frequencies for Application in Isolated Microgrid
Jondal Helle, Haakon (Master thesis, 2017)THE introduction of new methods for production and distribution of electrical energy has increased the attention related to problems with power quality and the presence of time-varying frequencies. It has been reported ... -
Re-synchronization of Universal Droop Control Distributed Generation Inverter to the Grid
Amin, Mohammad; Zhong, Qing-Chang (Chapter, 2019)The distributed generation (DG) inverters can operate in an islanded mode and a grid-connected mode. Under grid fault conditions, the inverter is disconnected from the main grid and operates in the islanded mode. When DG ... -
Resynchronization of Distributed Generation based on the Universal Droop Controller for Seamless Transfer Between Operation Modes
Amin, Mohammad; Zhong, Qing-Chang (Journal article; Peer reviewed, 2019)Distributed generation (DG) inverters can operate in the islanded mode and the grid-connected mode. When these DG inverters operate in the islanded mode, they often form a microgrid. The magnitude and phase of the main ... -
Self-synchronisation of wind farm in MMC-based HVDC system
Amin, Mohammad; Molinas Cabrera, Maria Marta (Chapter; Conference object, 2016)The stability of an offshore wind power network connected through a high voltage dc (HVDC) transmission line is a critical problem since there is no direct connection to a strong ac collection (ACC) bus. Field experience ... -
Small-signal Stability Characterization of Interaction Phenomena between HVDC System and Wind Farms
Amin, Mohammad (Doctoral theses at NTNU;2017:210, Doctoral thesis, 2017)The main objectives of this research work are to determine the underlying mechanisms leading to instability in a system with dominant presence of tightly regulated power electronics components and to identify the causal ... -
Subsynchronous Oscillation Mechanism and Its Suppression in MMC-Based HVDC Connected Wind Farms
Lyu, Jing; Cai, Xu; Amin, Mohammad; Molinas Cabrera, Maria Marta (Journal article, 2017)A subsynchronous oscillation (SSO) phenomenon in a wind farm integrated with a modular multilevel converter (MMC)-based high-voltage direct current (HVDC) transmission system has been recently observed in the real world. ... -
Understanding the Origin of Oscillatory Phenomena Observed between Wind Farms and HVDC Systems
Amin, Mohammad; Molinas Cabrera, Maria Marta (Journal article; Peer reviewed, 2016)Field experience has shown that sub-synchronous oscillation (SSO) and harmonic resonance can occur between wind farms (WFs) and high voltage dc (HVDC) systems. The oscillations can appear in the presence of background ...