Download or read book Wind Farms Interfacing Weak AC Grids Through HVDC Systems written by Jagdeep Kaur and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a comprehensive modeling and stability analysis framework to understand various challenges faced by weak AC grids (due to low system inertia and Effective Short Circuit Ratio (ESCR)) interfacing onshore wind farms, which transfer power to remote locations using High Voltage DC (HVDC) transmission systems. Different control strategies are also proposed to mitigate issues related to frequency dynamics and voltage regulation in such grids.First, the impact of inertia and ESCR on the control of frequency in progressively weak grid interfacing wind farms and the rectifier-side of Line Commutated Converter (LCC-HVDC) is analyzed. To that, end a small-signal stability analysis framework is developed for a Doubly-fed Induction Generator (DFIG)-based wind farm interfacing an LCC-HVDC station in a weak AC grid where the HVDC rectifier operates in a frequency control mode. A three-step approach for the modal analysis and control design is proposed that helps develop an understanding of the interaction of system modes that are contributing to the frequency dynamicswhen the AC grid is made progressively weaker. Although insightful, this study is confined to a single wind farm and a single generator representing the entire AC grid.It is essential to consider a more practical case to a have a better understanding of system stability and effect of disturbances like loss of generation on frequency dynamics. Therefore, the AC grid with a multi-machine system and multiple wind farms connected to the LCC HVDC rectifier station through feeders are considered.The future planning scenario involving partial replacement of coal-fired plants with wind farms, and conversion of a coal-fired plant into a synchronous condenser is examined. This work reveals the contribution from LCC-HVDC towards the improvement of the secondary frequency control of such system under severe faults following the loss of generation.Apart from the above-mentioned challenges related to frequency dynamics in the weak AC grid, there are other challenges including risks of voltage instability and commutation failure. In particular, the risk of commutation failure increases if the AC grid in the inverter-side is weak. Going forward, weak AC grids are assumed in both ends of the HVDC transmission system. The LCC converter stations rely on the AC system voltage for commutation and in turn, consumes reactive power, thereby increasing the risk of system instability with a weak AC system. A capacitor commutated converter (CCC) with capacitors in series with the valve-side transformer windings can be used to remedy some of these concerns. Currently, back-to-back CCC-HVDC systems are in operation. To explore the performance of CCC for a long-distance HVDC transmission system, a comprehensive nonlinear state-space modeling framework has been developed where both the sending as well as the receiving end grids are weak in nature. The modeling adequacy aspect of CCC is revisited and examined, which reveals the necessity of including the commutation capacitor voltage dynamics for time-domain and frequency domain analysis.Unlike LCC or CCC, Self Commutated Converters (e.g. Voltage Source Converters (VSCs)) do not rely on the AC system voltage for commutation. They can operate in leading, lagging, and unity power factor, and can regulate real and reactive power independently. As a result, they perform better with weak grids. However, VSC technology is more expensive, less efficient, and cannot carry high power of the order of LCC or CCC HVDC. To take advantages of both technologies, a Hybrid-HVDC concept is proposed, which includes a CCC coupled in series with a VSC, called Vernier, on DC side. Moreover, a coordinating control for Hybrid-HVDC converter systems is proposed, which ensures that - CCC and Vernier equitably share the control burden; the tap changers and switched capacitor banks are eliminated by Vernier controls that maintain constant firing angle and margin angle at the rectifier and inverter, respectively; and Vernier provides volt-VAr control at the commutation bus. The operating characteristics of the proposedHybrid-HVDC system is established.Finally, as a logical progression, the possibility of deriving secondary frequency support from wind farms and providing it to the inverter-side weak grid through Hybrid HVDC systems is explored. The flexible DC voltage polarity of the Vernier gives additional degrees of freedom to the control scheme, which is used for secondaryfrequency control in the inverter side grid by extracting power from the rectifier-end while maintaining constant firing angle and margin angle. Analytical insight of this complex system is developed to improve damping of frequency dynamics and improve utilization of the vernier capacity.

Download or read book Integrating Wind Energy to Weak Power Grids using High Voltage Direct Current Technology written by Nilanjan Ray Chaudhuri and published by Springer. This book was released on 2019-01-02 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first of its kind to provide a comprehensive framework for connecting wind farms to weak power grids using High Voltage DC technology. Most onshore wind energy potential is located in areas that are hardly inhabited and the majority of wind energy that is being harnessed by European countries is currently offshore, both sourced from locations that lack the presence of a strong power grid. This book focuses on the many challenges the wind farm industry faces integrating both onshore and offshore wind to ‘weak’ grids using HVDC technology. Through case studies and illustrative examples the author presents a framework for theoretical and mathematical analysis of HVDC technology, its application and successful integration of onshore and offshore wind farms. Presents a unified approach for integrating onshore and offshore wind energy to existing AC systems through MTDC grids; Includes an extensive treatment of onshore wind farms connected to LCC HVDC systems; Provides a comprehensive analysis of offshore wind farms connected to VSC HVDC systems.

Download or read book Hybrid AC DC Power Grids Stability and Control Aspects written by Lasantha Meegahapola and published by Springer Nature. This book was released on 2022-08-18 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers modeling, control and stability aspects of hybrid AC/DC power networks. More specifically, this book provides an in-depth analysis of the stability and control aspects of hybrid AC/DC power grids, with comprehensive coverage of theoretical aspects of conventional stability issues (e.g., small-signal stability, voltage stability and frequency stability), emerging stability issues (e.g., converter associated stability) and control strategies applied in this emerging hybrid AC/DC power grids. This book takes a more pragmatic approach with a unique compilation of timely topics related to hybrid AC/DC networks compared with other books in this field. Therefore, this book provides the reader with comprehensive information on modeling, control and stability aspects which need to consider when modeling and analysis of hybrid AC/DC power grids for power system dynamics and stability studies. Each chapter provides fundamental stability theories, some worked examples and case studies to explain various modeling, analysis and control concepts introduced in the chapter. Therefore, postgraduate research students, power system researchers and power system engineers benefit from the materials presented in this book and assist them to model and device new control strategies to overcome the stability challenges of the emerging hybrid AC/DC power grid.

Download or read book HVDC Grids written by Dirk Van Hertem and published by John Wiley & Sons. This book was released on 2016-02-29 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses HVDC grids based on multi-terminal voltage-source converters (VSC), which is suitable for the connection of offshore wind farms and a possible solution for a continent wide overlay grid. HVDC Grids: For Offshore and Supergrid of the Future begins by introducing and analyzing the motivations and energy policy drives for developing offshore grids and the European Supergrid. HVDC transmission technology and offshore equipment are described in the second part of the book. The third part of the book discusses how HVDC grids can be developed and integrated in the existing power system. The fourth part of the book focuses on HVDC grid integration, in studies, for different time domains of electric power systems. The book concludes by discussing developments of advanced control methods and control devices for enabling DC grids. Presents the technology of the future offshore and HVDC grid Explains how offshore and HVDC grids can be integrated in the existing power system Provides the required models to analyse the different time domains of power system studies: from steady-state to electromagnetic transients This book is intended for power system engineers and academics with an interest in HVDC or power systems, and policy makers. The book also provides a solid background for researchers working with VSC-HVDC technologies, power electronic devices, offshore wind farm integration, and DC grid protection.

Download or read book Integration of High Voltage AC DC Grids into Modern Power Systems written by Fazel Mohammadi and published by MDPI. This book was released on 2020-12-10 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electric power transmission relies on AC and DC grids. The extensive integration of conventional and nonconventional energy sources and power converters into power grids has resulted in a demand for high voltage (HV), extra-high voltage (EHV), and ultra-high voltage (UHV) AC/DC transmission grids in modern power systems. To ensure the security, adequacy, and reliable operation of power systems, the practical aspects of interconnecting HV, EHV, and UHV AC/DC grids into the electric power systems, along with their economic and environmental impacts, should be considered. The stability analysis for the planning and operation of HV, EHV, and UHV AC/DC grids in power systems is regarded as another key issue in modern power systems. Moreover, interactions between power converters and other power electronics devices (e.g., FACTS devices) installed on the network are other aspects of power systems that must be addressed. This Special Issue aims to investigate the integration of HV, EHV, and UHV AC/DC grids into modern power systems by analyzing their control, operation, protection, dynamics, planning, reliability, and security, along with considering power quality improvement, market operations, power conversion, cybersecurity, supervisory and monitoring, diagnostics, and prognostics systems.

Download or read book Multi terminal VSC based HVDC Systems for Offshore Wind Energy Systems Integration written by AlMutasim AlSammari and published by . This book was released on 2014 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The installation of wind energy has rapidly increased in the last decade, especially in countries in Europe and East Asia. Offshore wind energy is expected to be one of the major power generation sources in the near future. However, the integrating of offshore wind plants into onshore ac grids remains a challenge in both technical and economic terms. Offshore wind plants can be connected to ac grids using ac or dc transmission systems. HVDC transmission is favored over HVAC transmission as the transmission distance increases. Recently, with the improvement in the field of semiconductor, it became possible to build a VSC-based HVDC system providing many benefits including the ability to independently control active and reactive power transfer. VSC-based Multiterminal HVDC (MTDC) transmission systems allows the interconnection of multiple offshore wind farms with multiple onshore ac grids. The challenges of building MTDC systems has been a hot topic in the past years and it appears this will continue into the future. Different control schemes based on droop characteristics have been presented as a means to regulate the dc voltage and control the power flow in MTDC transmission systems. In this thesis, the control and steady state operation of VSC-based MTDC systems is studied. A generalized control scheme based on droop characteristics is presented. The control methodology is based on the design of the droop constants to control the grid side VSCs for three different operational modes taking into consideration the varying nature of wind power. The three operational modes differ in how the generated wind power is distributed between the ac grids in the MTDC system. The difficulties and challenges of adding tap stations on HVDC lines in MTDC systems is also discussed in the thesis. A new control scheme approach for adding multiple taps on HVDC lines in MTDC systems is presented. A switching VSC models of the MTDC systems discussed throughout the thesis are built in Matlab/Simulink software. The models are simulated for different case scenarios to verify the control and normal operation of the systems.

Download or read book Operation and Control of Transmission Systems for Offshore Wind Power Plants written by Mònica Aragüés Peñalba and published by . This book was released on 2016 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis deals with grid integration of oshore wind power plants through HVDC (High Voltage Direct Current) or HVAC (High Voltage Alternating Current) transmission . The behaviour of wind farms and their transmission systems in normal operation and under faults is analyzed. On the eld of HVDC transmission , a control scheme based on an optimum voltage algorithm is proposed and compared to voltage droop control. The dierences between the proposed scheme and droop control in terms of losses are analyzed, in steady state as well as dynamically. This new control scheme is enhanced, being able to perform secondary and tertiary control strategies simultaneously for DC grids. Concerning HVAC transmission, the operation of AC connected wind power plants equipped with full power converter wind turbines is analyzed under deep voltage sags on the main AC grid. Standard control schemes, based on the strict application of grid codes, can lead to instability problems when this kind of severe disturbances occurs. A coordinated control scheme is proposed to operate the system, ensuring fault ride through capability. An index alerts of instability proximity and allows to actívate active power and reactive power regulation to guarantee safe operation during faults. For enabling the optimal operation of transmission systems, an optimal power flow tool is described for hybrid HVDC-HVAC systems, for different objective functions. This tool is tested in a scaled platform. Finally, the secure and optimal operation of these systems is analysed for a scenario with high penetration of oshore wind, proposing a methodology to evaluate the cost of operation and wind energy curtailed.

Download or read book Integration of Large Wind Farms to Weak Power Grids written by Kamyab Givaki and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power grids are changing significantly with the introduction of large amounts of renewable energy (especially wind) into the system. Integration of wind energy into the grid is challenging as, firstly it increases penetration stresses when compared to conventional generation as the wind is intermittent and fluctuates in power output. Secondly, most of the wind farms are located in offshore or rural areas which have good wind conditions. The grid in these regions is not normally strong. Most of the modern variable speed wind turbines use voltage source converters (VSCs) for grid integration. However, integrating VSCs to weak power grids will cause instability when a large amount of active power is transferred to the grid. In this thesis, the integration of wind farms to very weak power grids is investigated. A multiple input, multiple output (MIMO) model of the grid side VSC of a wind turbine is developed in the frequency domain in which the d-axis of the synchronous reference frame (SRF) is aligned with the grid voltage. Then, this model has been used as the basis for modelling the multiple parallel converters in the frequency domain. In this thesis, to improve the stability of the very weak grid connected of VSCs, a control method based on the d- and q- axis current error is introduced. This controller compensates the output angle of the phase locked loop (PLL) and the voltage amplitude of the converter. Using this controller, full rated active power transfer and fault ride-through are achieved under very weak grid connection. Furthermore, a stabiliser controller based on virtual impedance is proposed in this thesis to achieve stable operation of a very weak grid connected VSC. This stabilising control method enables the VSC to operate at full power and to ride-through faults under very weak grid conditions. Based on this principle, an external device is proposed that can be utilised and connected to a weak point of the grid to allow a large amount of VSC interfaced power generation (e.g. wind power) to be connected to the grid without introducing stability issues.

Download or read book Synchronous Machine Emulation of Vsc for Interconnection of Renewable Energy Sources Through HVDC Transmission written by Mohamed Asker Kanakkayil and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The majority of the energy demand over the past years has been fulfilled by centralized generating stations. However, with a continuously increasing energy demand, the integration of decentralized renewable energy sources (RES) into the power system network becomes inevitable even though these sources affect the stability of the grid due to their intermittency and use of various power converters. The transmission of power over long distances from RES is usually accomplished either by AC or DC transmission. High voltage DC transmission (HVDC) is preferred over high voltage AC transmission (HVAC) due to numerous and complex reasons, such as its lower investment cost for long transmission cables, lower losses, controllability, and limited short circuit currents. Several control methods for grid-connected voltage source converters (VSCs), such as power-angle and vector-current controls, are being adopted in RES interconnections. However, these methods face several issues when used for a weak grid interconnection. This thesis develops a control strategy for a VSC–HVDC transmission system by referring to the synchronverter concept. In the proposed method, the sending-end rectifier controls emulate a synchronous motor (SM), whereas the receiving end inverter emulates a synchronous generator (SG) to transmit power from one grid to another. The two converters connected by a DC line provide a synchronverter HVDC (SHVDC) link. Given the high demand for sustainable energy, integrating RES—which can be extended to wind-based resources—into the long-haul HVDC link becomes essential. Therefore, in this thesis, a windfarm with a type 4 permanent magnet SG is integrated into the HVDC link through a rectifier. Depending on the wind speed, the proposed control strategy automatically shares and manages the wind generator power on the DC side by using a battery energy storage system (BESS) connected to the HVDC link to stabilize the power fluctuations generated by the intermittency of the wind farm. The performance of the synchronverter-based HVDC transmission was verified by using a MATLAB Simulink model. Results show that the controller can effectively control the power flow from one grid to another and that the effect of wind fluctuation on the grid can be mitigated by introducing a BESS at the DC link. Therefore, by properly controlling the SHVDC, BESS, and RES connected to the HVDC system, the power from remote RES can be connected to a weak AC grid in a stable manner.

Download or read book Multi terminal VSC HVDC Based Offshore Wind farms Integration System Operation and Control written by Mohamed A. Abdelwahed and published by . This book was released on 2017 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Worldwide, many countries direct billions of dollars into the development of renewable energy sources; especially wind generation, in an effort to relieve global warming effects and other environmental concerns. As a result of increasing numbers of remotely-located large power offshore wind farms, the AC grid faces many technical challenges in integrating such plants; such as large submarine power transmission for extended distances, power sharing and transfer, as well as remotely located induction generation reactive power support. Offshore multi-terminal VSC based HVDC (MT VSC-HVDC) transmission systems represent a possible means of dealing with those challenges. This is due to their higher capacity, flexibility and controllability than offshore AC transmission. In addition, these offshore grids provide grid integration to remote offshore wind farms leading providing additional interconnection capacity to improve the trade of electricity between different AC grids. This work presents a new centralized supervisory control strategy for controlling the power sharing and voltage regulation of MT VSC-HVDC integrating offshore wind farms. The main purpose of the proposed strategy is selecting the optimal parameters of the HVDC system VSCs' local controller. These optimal parameters are selected in order to achieve optimal system transient response and desired steady state operation. In this work, an adaptive droop-based power-sharing control strategy is proposed. The primary objective is to control the sharing of the active power transmitted by a MT VSC-HVDC network among a number of onshore AC grids or offshore loads based on the desired percentage shares. The shared power is generated by remote generation plants (e.g., offshore wind farms) or is provided as surplus of AC grids. The desired percentage shares of active power are optimized by the system operator to fulfill the active power requirements of the connected grids with respect to meeting goals such as supporting energy adequacy, increasing renewable energy penetration, and minimizing losses. The control strategy is based on two hierarchal levels: voltage-droop control as the primary controller and an optimization based secondary (supervisory) controller for selecting the optimal droop reference voltages. Based on the DC voltage transient and steady state dynamics, a methodology for choosing the droop gains for droop controlled converters has been developed. In addition, a new tuning methodology is proposed for selecting the optimum VSCs local controller gains to enhance the transient performance and the small-signal stability of the system to mitigate the change of the operating conditions, taking into consideration the overall dynamics of the MT HVDC system. The VSCs' local control loops gains are selected to maximize the system bandwidth and improve the system damping. As a part of the proposed methodology, the derivation of the aggregated linearized state-space model of a MT VSC-HVDC based offshore transmission system is provided. Based on the derived model, a small signal stability analysis was performed to show the interaction of the modes and define the dominant eigenvalues of the system. Furthermore, a communication-free DC voltage control strategy is presented for mitigating the effects of the power imbalance caused by permanent or temporary power-receiving converter outages. The proposed control strategy is targeted at fast power reduction of the wind power generation from the wind farms (WFs) in order to eliminate power imbalances in the HVDC network. This process is performed by decentralized control rules in the local controllers of the WF voltage source converter (VSC) and its wind turbines. The proposed strategy was designed to work with WFs based on both doubly fed induction generators (DFIGs) and permanent magnet synchronous generators (PMSGs). The proposed control strategies were validated on the B4 CIGRE MT VSC-HVDC test system and different case scenarios were applied to show its feasibility and robustness. The validation process was performed using Matlab software programming and Matlab/Simulink based time domain detailed model.

Download or read book Power Flow Modelling of HVDC Transmission Systems written by Shagufta Khan and published by CRC Press. This book was released on 2022-12-23 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals exclusively with the power-flow modelling of HVDC transmission systems. Different types of HVDC transmission systems, their configurations/connections and control techniques are covered in detail. Power-Flow modelling of both LCC- and VSC-based HVDC systems is covered in this book. Both the unified and the sequential power-flow methods are addressed. DC grid power-flow controllers and renewable energy resources like offshore wind farms (OWFs) are also incorporated into the power-flow models of VSC-HVDC systems. The effects of the different power-flow methods and HVDC control strategies on the power-flow convergence are detailed along with their implementation. Features: Introduces the power-flow concept and develops the power-flow models of integrated AC/DC systems. Different types of converter control are modelled into the integrated AC/DC power-flow models developed. Both unified and the sequential power-flow methods are addressed. DC grid power-flow controllers like the IDCPFC and renewable energy resources like offshore wind farms (OWFs) are introduced and subsequently modelled into the power-flow algorithms. Integrated AC/DC power-flow models developed are validated by implementation in the IEEE 300-bus and European 1354-bus test networks incorporating different HVDC grids. This book aims at researchers and graduate students in Electrical Engineering, Power Systems, and HVDC Transmission.

Download or read book Integration of Wind Farms Into Weak AC Grid written by Manal Nawir and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Efficiency and Performance Analysis of AC and DC Grid Based Wind Farms Connected to a High Voltage DC Transmission Line written by Jonathan Robinson and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Small Signal Stability Analysis of Power Systems Integrated with Variable Speed Wind Generators written by Wenjuan Du and published by Springer. This book was released on 2018-09-03 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews and examines how power system low-frequency power oscillations and sub-synchronous oscillations may be affected by grid connection of wind power generation. Grid connection of wind power generation affects the power system small-signal stability and has been one of the most actively pursued research subjects in power systems and power electronics engineering in the last ten years. This book is the first of its kind to cover the impact of wind power generation on power system low-frequency oscillations and sub-synchronous oscillations. It begins with a comprehensive overview of the subject and progresses to modeling of power systems and introduces the application of conventional methods, including damping torque analysis, modal analysis and frequency-domain analysis, presented with detailed examples, making it useful for researchers and engineers worldwide.

Download or read book DC Wind Generation Systems written by Omid Beik and published by Springer Nature. This book was released on 2020-03-04 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the design and operation of DC wind systems and their integration into power grids. The chapters give an in-depth discussion on turbine conversion systems that have been adapted for DC grids and address characteristics of wind turbines when converting kinetic wind energy to electrical energy, components associated with DC systems, and the design and analysis of DC grids. Additionally, the performance of medium voltage DC (MVDC) array grid and high voltage DC (HVDC) transmission grid connected via an offshore substation with DC/DC converters are also addressed. The book examines multiphase hybrid excitation generator systems for wind turbines and discusses its design and operation for all DC systems. The book provides an insight into the state-of-the-art technological advancements for existing and futuristic wind generation schemes, and provides materials that will allow students, researchers, academics, and practicing engineers to learn, expand and complement their expertise.

Download or read book HVDC FACTS for Grid Services in Electric Power Systems written by José M. Maza-Ortega and published by MDPI. This book was released on 2020-11-23 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electric power systems are headed for a true changing of the guard, due to the urgent need for achieving sustainable energy delivery. Fortunately, the development of new technologies is driving the transition of power systems toward a carbon-free paradigm while maintaining the current standards of quality, efficiency, and resilience. The introduction of HVDC and FACTS in the 20th century, taking advantage of dramatic improvements in power electronics and control, gave rise to unprecedented levels of flexibility and speed of response in comparison with traditional electromechanical devices. This flexibility is nowadays required more than ever in order to solve a puzzle with pieces that do not always fit perfectly. This Special Issue aims to address the role that FACTS and HVDC systems can play in helping electric power systems face the challenges of the near future.

Download or read book Energy Shaping Control for Stabilization of Interconnected Voltage Source Converters in Weakly connected AC Microgrid Systems written by Nadia Lenora Carmita Smith and published by . This book was released on 2017 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the ubiquitous installations of renewable energy resources such as solar and wind, for decentralized power applications across the United States, microgrids are being viewed as an avenue for achieving this goal. Various independent system operators and regional transmission operators such as Southwest Power Pool (SPP), Midcontinent System Operator (MISO), PJM Interconnection and Electric Reliability Council of Texas (ERCOT) manage the transmission and generation systems that host the distributed energy resources (DERs). Voltage source converters typically interconnect the DERs to the utility system and used in High voltage dc (HVDC) systems for transmitting power throughout the United States. A microgrid configuration is built at the 13.8kV 4.75MVA National Center for Reliable Energy Transmission (NCREPT) testing facility for performing grid-connected and islanded operation of interconnected voltage source converters. The interconnected voltage source converters consist of a variable voltage variable frequency (VVVF) drive, which powers a regenerative (REGEN) load bench acting as a distributed energy resource emulator. Due to the weak-grid interface in islanded mode testing, a voltage instability occurs on the VVVF dc link voltage causing the system to collapse. This dissertation presents a new stability theorem for stabilizing interconnected voltage source converters in microgrid systems with weak-grid interfaces. The new stability theorem is derived using the concepts of Dirac composition in Port-Hamiltonian systems, passivity in physical systems, eigenvalue analysis and robust analysis based on the edge theorem for parametric uncertainty. The novel stability theorem aims to prove that all members of the classes of voltage source converter-based microgrid systems can be stabilized using an energy-shaping control methodology. The proposed theorems and stability analysis justifies the development of the Modified Interconnection and Damping Assignment Passivity-Based Control (Modified IDA-PBC) method to be utilized in stabilizing the microgrid configuration at NCREPT for mitigating system instabilities. The system is simulated in MATLAB/SimulinkTM using the Simpower toolbox to observe the system's performance of the designed controller in comparison to the decoupled proportional intergral controller. The simulation results verify that the Modified-IDA-PBC is a viable option for dc bus voltage control of interconnected voltage source converters in microgrid systems.