Entire Grid Research Articles

Securing the smart grid: threats and remediation

The implementation of the smart grid brings many improvements over the traditional energy grid by leveraging a vast interconnected infrastructure that allows two way communication and automation throughout the entire grid. A key difference over the existing grid is the introduction of the advanced metering infrastructure (AMI) which contains many new components such as the smart meter and the communication gateways. The focus of this paper is to examine the possible effects on the energy supply should these devices become compromised. Smart meters are one of the most important components in the smart grid implementation which allow a real time flow of information to/from the consumer on their energy usage. The paper also discusses how closing coal and oil power plant has increased our demand on gas power stations in the UK. Our experiments show that manipulating smart meter readings can create a massive shortfall in gas provisioning.

Application of Hierarchical and Distributed Cognitive Architecture Management for the Smart Grid

Moving from the current power grid to the Smart Grid (SG) requires decentralizing management. This should be done by distributing intelligence over the entire grid, thereby, the intermittent production of renewable energy, customer consumption and electricity storage in electrical vehicles (EVs) could be managed in real time. In this paper, the Hierarchical and Distributed Cognitive Radio Architecture Management (HDCRAM), initially proposed to manage Cognitive Radio systems, is proposed for the management of the SG. This architecture can both be applied to the whole SG and to any sub-part (distribution network, production network, microgrid). In this paper we focus on the distribution network and the hierarchical position of each element is identified. As an example, HDCRAM is used for smart home management and multi-agent based modeling shows benefits of such an architecture. In the simulated scenario, without any management the peak power consumption is 5500 W and the hierarchical and distributed management allows to reduce it to 900 W. This diminution allows to reduce the pressure on the grid and can decrease the risk of failure.

EFFECT OF UV RADIATION ON THE SPECTRAL FINGERPRINTS OF EARTH-LIKE PLANETS ORBITING M STARS

We model the atmospheres and spectra of Earth-like planets orbiting the entire grid of M dwarfs for active and inactive stellar models with $T_{eff}$ = 2300K to $T_{eff}$ = 3800K and for six observed MUSCLES M dwarfs with UV radiation data. We set the Earth-like planets at the 1AU equivalent distance and show spectra from the VIS to IR (0.4$\mu$m - 20$\mu$m) to compare detectability of features in different wavelength ranges with JWST and other future ground- and spaced-based missions to characterize exo-Earths. We focus on the effect of UV activity levels on detectable atmospheric features that indicate habitability on Earth, namely: H$_2$O, O$_3$, CH$_4$, N$_2$O and CH$_3$Cl. To observe signatures of life - O$_2$/O$_3$ in combination with reducing species like CH$_4$, we find that early and active M dwarfs are the best targets of the M star grid for future telescopes. The O$_2$ spectral feature at 0.76$\mu$m is increasingly difficult to detect in reflected light of later M dwarfs due to low stellar flux in that wavelength region. N$_2$O, another biosignature detectable in the IR, builds up to observable concentrations in our planetary models around M dwarfs with low UV flux. CH$_3$Cl could become detectable, depending on the depth of the overlapping N$_2$O feature. We present a spectral database of Earth-like planets around cool stars for directly imaged planets as a framework for interpreting future lightcurves, direct imaging, and secondary eclipse measurements of the atmospheres of terrestrial planets in the HZ to design and assess future telescope capabilities.

Transmission line fault detection and localisation methodology using PMU measurements

Rapid advancements pertaining to measurements and computational technology have brought a paradigm shift for operational architecture of power grids across the globe. Self-healing, a vital operational feature of emerging power grids, necessitates real-time identification and localisation of transmission line faults for the entire power network. This study proposes a novel support vector machine-based fault localisation methodology to precisely identify and localise all types of transmission line faults occurring at any location in the power grid based on phasor measurement unit (PMU) measurements. Detection of fault is achieved through PMU measurements only from a single generator bus for the entire grid. Bus associated with fault, faulty branch and location of fault in faulty branch are calculated using fast Fourier transform analysis of variations pertaining to equivalent voltage phasor angle (EVPA) and equivalent current phasor angle (ECPA). The proposed methodology has been validated through extensive case studies for Western System Coordinating Council (WSCC)-9 and IEEE-14 bus systems. The main contribution of the proposed methodology is that the fault location information can significantly contribute to system protection center for restoration of the line within shortest time span and initiate appropriate wide area control actions to maintain stability.

Investigation on the unstructured rotational dynamic overset grids

Purpose – The purpose of this paper is to investigate and improve a new method of unstructured rotational dynamic overset grids, which can be used to simulate the unsteady flows around rotational parts of aircraft. Design/methodology/approach – The computational domain is decomposed into two sub-domains, namely, the rotational sub-domain which contains the rotational boundaries, and the stationary sub-domain which contains the remainder flow field including the stationary boundaries. The artificial boundaries and restriction boundaries are used as the restriction condition to generate the entire computational grid, and then the overset grids are established according to the radius parameters of artificial boundaries set previously. The deformation of rotational boundary is treated by using the linear spring analogy method which is suitable for the dynamic unstructured grid. The unsteady Navier-Stokes/Euler equations are solved separately in the rotational sub-domain and stationary sub-domain, and data cou...

Long-Term Voltage Instability Detections of Multiple Fixed-Speed Induction Generators in Distribution Networks Using Synchrophasors

As the penetration of renewable energy sources is increasing, the long-term voltage stability (LTVS) of fixed-speed induction generators (FSIGs) has raised a major concern for distribution power networks since they will always consume reactive power. When either the voltage profile of the FSIG severely declines due to the load consumption increasing in the nearby area, or the mechanical power of the wind turbine increases owing to the wind speed increasing, the loss of the stable equilibrium point will result in this class of long-term voltage instability problems. Although this problem is a local phenomenon, it may spread to the rest of the system and cause the cascaded blackout. Meanwhile, with massive deployment of synchrophasor technology, it is possible to improve system awareness and enable early warning to detect this class of LTVS problems in real-time. In this paper, a measurement-based algorithm for synchrophasor long-term voltage stability indicator (SLVSI) will be proposed. First, qualitative analysis of this class of LTVS problems is conducted by corresponding bifurcation diagrams and hysteretic curves. Secondly, a measurement-based FSIG equivalent model is proposed by utilizing real-time phasor measurements from synchrophasors. The above concept can be extended to distribution power networks with multiple FSIGs. The entire distribution power grid will be considered as a modified coupled single-port network. By exploring the concept of reactive power response factor, the corresponding Thevenin equivalent parameter of each individual FSIG branch is adjusted based on real-time phasor measurements. Thus, a SLVSI for each individual FSIG can be defined by modifying the conventional $L$ -index. Simulation experiments on two IEEE test systems are performed to validate the accuracy of the proposed SLVSI.

Application of Joint Electro-Chemical Detection for Gas Insulated Switchgear Fault Diagnosis

The integrity of the gas insulated switchgear (GIS) is vital to the safety of an entire power grid. However, there are some limitations on the techniques of detecting and diagnosing partial discharge (PD) induced by insulation defects in GIS. This paper proposes a joint electro-chemical detection method to resolve the problems of incomplete PD data source and also investigates a new unique fault diagnosis method to enhance the reliability of data processing. By employing ultra-high frequency method for online monitoring and the chemical method for detecting SF6 decomposition offline, the acquired data can form a more complete interpretation of PD signals. By utilizing DS evidence theory, the diagnostic results with tests on the four typical defects show the validity of the new fault diagnosis system. With higher accuracy and lower computation cost, the present research provides a promising way to make a more accurate decision in practical application.

Design and Evaluation of PMU Performance Measurement and GPS Monitoring System for Power Grid Stabilization

Power grid techniques are distributed over general power systems ranging from power stations to power transmission, power distribution, and users. To monitor and control the elements and performance of a power system in real time in the extensive area of power generation, power transmission, wide-area monitoring (WAM) and control techniques are required (<xref>Sattinger et al. 2007</xref>). Also, to efficiently operate a power grid, integrated techniques of information and communication technology are required for the application of communication network and relevant equipment, computing, and system control software. WAM should make a precise power grid measurement of more than once per cycle by time synchronization using GPS. By collecting the measurement values of a power grid from substations located at faraway regions through remote communication, the current status of the entire power grid system can be examined. However, for GPS that is used in general national industries, unexpected dangerous situations have occurred due to its deterioration and jamming. Currently, the power grid is based on a synchronization system using GPS. Thus, interruption of the time synchronization system of the power system due to the failure or abnormal condition of GPS would have enormous effects on each field such as economy, security, and the lives of the public due to the destruction of the synchronization system of the national power grid. Developed countries have an emergency substitute system in preparation for this abnormal situation of GPS. Therefore, in Korea, a system that is used to prepare for the interruption of GPS reception should also be established on a long-term basis; but prior to this, it is required that an evaluation technique for the time synchronization performance of a GPS receiver using an atomic clock within the power grid. In this study, a monitoring system of time synchronization based on GPS at a power grid was implemented, and the results were presented.

The Effect of Phase-to-earth Faults on the Operating Conditions of a Separated 110 kV Grid Normally Operated with Effectively Earthed Neutral, and Temporarily Supplied from a Compensated 110 kV Grid

The paper discusses the interoperability of the German compensated 110 kV grid and the Polish effectively earthed 110 kV grid. It is assumed that an area of one grid, separated from its power system, will be temporarily supplied from the other grid in its normal regime. Reference is made to the risks associated with phase-to-earth faults in grids so interconnected. Particular attention is paid to the working conditions of surge arresters and voltage transformers in the Polish 110 kV grid deprived of its neutral earthing when supplied from the German grid. DOI: 10.12736/issn.2300-3022.2015211 Background The established cooperation of the Polish National Power System (NPS) with the systems of neighbouring countries takes place at the level of the 220 kV and 400 kV transmission grids, while, for obvious reasons, there have been no interconnections between 110 kV lines. Local cooperation between nearborder 110 kV grid operators can contribute to improved security of supply, and often may be commercially reasonable. When organizing such interoperation, an area of one grid should be prepared, which will be isolated from its own power system and temporarily supplied from the other grid in its normal regime (connected with its power system). The grids will alternate in their supplier/recipient roles. Such interoperation may be relatively easily organised between 110 kV grids with the same neutral earthing modes, and similar standards of power system protections. Such interoperation has been already established, for example between Polish and Czech operators, whose 110 kV grids operate with effectively earthed neutrals. It becomes more complicated when one of the 110 kV grids is effectively earthed, and the other is compensated, as is the case with the neighbouring Polish and German grids. Interoperability analysis of the supply of a separated portion of the Polish 110 kV grid from the compensated German 110 kV grid leads to the following conclusions: • In a fault-free condition, grid interoperation is risk-free. • Given the possibility of short circuits, including phase-toearth faults, no transformer in the separated portion of the Polish grid can have the star point earthed on the 110 kV side. • For the Polish 110 kV grid an earth fault may prove to be dangerous, regardless of its location (in either the Polish or German grid). The overvoltages occurring in these conditions in the healthy phases in the entire grid with coefficient ku = may endanger the Polish grid, which is suitable for overvoltages with coefficient ku ≤ 1.4. • The Polish 110 kV grid protection systems are not suitable to identify and eliminate earth faults in the considered conditions, while the earth faults in the compensated German grid are signalised only by the protection. Ground faults are eliminated through operational activities, with considerable delay. Interoperability analysis of the supply of a separated portion of the German 110 kV grid from the effectively earthed Polish 110 kV grid leads to the following conclusions: • In a fault-free condition, grid interoperation is risk-free. • In the event of phase-to-earth fault in the compensated German grid its earthing and protection systems may prove inadequate for large short-circuit currents. The issue of the interoperability of effectively earthed and compensated 110 kV grids is not new. In the postwar period there was such a need in the Upper Silesian region, and the problem was solved by using a special 110 kV/110 kV coupling transformer. This solution radically eliminates many problems, but has a very significant drawback – it is expensive. It is estimated that for a 160 MVA transformer, the total cost of its building and fitting could amount to approx. 2.5 million EUR. W. Rojewski, M. Sobierajski | Acta Energetica 2/23 (2015) | 114–119

Statistical Analysis on Lightning Performance of Transmission Lines in Several Regions of China

Lightning is a substantial cause that leads to serious lightning failures, which has a significant influence on the normal operation of the entire power grid. This paper mainly focused on several regions of China with serious lightning activity, presenting the lightning performance of power grids by statistics obtained from long-term monitoring data, and intended to indicate some general characteristics. The lightning tripout rate, the shielding failure tripout ratio, the occurrence frequency corresponding tripout failures of different phases of single-circuit or double-circuit transmission lines, and the multicircuit simultaneous tripout failures of multicircuit transmission lines were analyzed. These statistical results presented a panorama of the lightning protection effect of transmission lines in China. The statistical data in this paper are informative to guide the future research or engineering practice of lightning protection of transmission lines, and will be helpful to evaluate the analysis methods of lightning performance of transmission lines.

A REVIEW ON SCHEDULING ALGORITHMS FOR RESOURCE MANAGEMENT IN DATA GRIDS

A very promising attractive computing model is Grid Computing. To provide high performance computing, grids aims to combine the geographically distributed, power of heterogeneous , multiple domain spanning computational resources. An efficient and effective scheduling system is important for achieving the capable potentials of grids. In grid environment, scheduling systems do not work for traditional distributed environments due to classes of environments which are completely dissimilar. Over various domains, making scheduling decisions involving resources is the process known as Grid Resource Scheduling. Across the management, grid scheduling must manipulate large-scale resources so there is high complication involved in it than the local resource scheduling. In this survey, discussion are made on grid scheduling algorithm with a view from different points which are objective function, QoS constraints, static vs. dynamic, strategies dealing with dynamic behavior of resources, application models, adaption and so on. This survey mainly focused a review of the subject from scheduling algorithm viewpoint rather than covering the entire grid scheduling area.

Tracing of shading effect on underachieving SPV cell of an SPV grid using wireless sensor network

The environmental and economic merits of converting solar energy into electricity via photovoltaic cells have led to its enormous growth in this sector. Besides material and design parameters, there are many other factors which locally affect Photovoltaic cell like partial shading, humidity, dust, bird droppings, air velocity etc. However, the effect due to a single solar photo voltaic cell being connected to a serial or parallel network (to form a grid) has never been deliberated extensively. In this paper a system design that will detect the underperforming panel in the entire grid is proposed and validated. All the Photo voltaic panels in a grid are connected with current sensors, which are connected to microcontrollers and these microcontrollers are locally connected with the wireless sensor network. With the help of wireless sensor network, grid monitoring for individual panel has been achieved for the first time with proposed system. The grid and control room is also connected wirelessly which enables the engineer monitoring the grid to meticulously locate the individual solar photovoltaic cell which is underachieving and solve the issue pertaining the same. The proposed system design has been validated with the help of data obtained with Centre for Wind Energy Technology (CWET), Govt. of India.”.

Fault Detection and Localization Methodology for Self-healing in Smart Power Grids Incorporating Phasor Measurement Units

Recent developments in several fields of engineering have accelerated the evolution of smart power grids encompassing both transmission and distribution systems across the globe. Self-healing, a crucial operational function of a smart power grid, requires detection as well as localization of the transmission line faults in the power network in real time. A support vector machine based fault-localization methodology has been proposed to accurately detect and localize any type of transmission line faults for the entire smart power grid. This methodology identifies the transmission line fault in smart power grid and precisely pinpoints the bus to which the faulty branch is connected. Afterward, the faulty branch is discriminated, and the distance of fault location from the bus related to the fault is estimated. The methodology relies on frequency-domain analysis of the equivalent voltage phasor angle and equivalent current phasor angle using fast Fourier transform. The proposed methodology has been corroborated using extensive case studies conducted on 7- and 13-bus power systems. The major contribution of the proposed methodology is that it can identify and localize all types of transmission line faults using phasor measurement unit measurements. The methodology can be applied for transmission systems as well as distribution systems.

Performability Evaluation of Grid Environments Using Stochastic Reward Nets

In this paper, performance of grid computing environment is studied in the presence of failure-repair of the resources. To achieve this, in the first step, each of the grid resource is individually modeled using Stochastic Reward Nets (SRNs), and mean response time of the resource for grid tasks is computed as a performance measure. In individual models, three different scheduling schemes called random selection, non-preemptive priority, and preemptive priority are considered to simultaneously schedule local and grid tasks to the processors of a single resource. In the next step, single resource models are combined to shape an entire grid environment. Since the number of the resources in a large-scale grid environment is more than can be handled using such a monolithic SRN, two approximate SRN models using folding and fixed-point techniques are proposed to evaluate the performance of the whole grid environment. Brouwer’s fixed-point theorem is used to theoretically prove the existence of a solution to the fixed-point approximate model. Numerical results indicate an improvement of several orders of magnitude in the model state space reduction without a significant loss of accuracy.

Reconstruction of optical scanned images of inhomogeneities in biological tissues by Monte Carlo simulation

The optical imaging of inhomogeneities located in phantoms of biological tissues, prepared from goat׳s isolated heart as control tissue and embedded with spleen and adipose tissues representing tumors, by Monte Carlo simulation, is carried out. The proposed scanning probe consists of nine units. Each unit is equipped with one photon injection port and three ports arranged in a straight line to collect backscattered photons emerging from various depths, and one port, placed coaxially to the source on the opposite side of the phantom, to collect the transmitted component. At each position of the grid, superposed on the tissue phantom, photons are introduced through source port into the phantoms and backscattered and transmitted photons are collected by respective ports. Based on the data collected from the entire grid surface the respective gray-level images are reconstructed. The inhomogeneity located at certain depth (2, 4, 6mm) is visualized in three images formed by the backscattered data collected by three ports. Increase or decrease in normalized backscattered intensity (NBI) observed in their scans corresponds to that of high scattering (adipose) or absorbing (spleen) inhomogeneity compared to that of control tissue and also their location as determined by NBI variation as received at various ports. The images constructed from the transmitted data are associated with decrease in intensity. The scans of these images through their centers show that normalized transmitted intensity (NTI) attains its maximum value when the inhomogeneities are at depth 6mm. These scans are of higher amplitude for spleen compared to that of adipose tissues. Thus the data received by backscattering and transmission complement each other in identifying the location and type of inhomogeneities.

Global analysis of peroxy radicals and peroxy radical-water complexation using the STOCHEM-CRI global chemistry and transport model

The importance of peroxy radical (RO2) chemistry in the troposphere is investigated using the STOCHEM-CRI global chemistry and transport model. The oxidation of VOCs leads to the formation of RO2 radicals which are dominated by CH3O2 (83%), RCO3 (5%), isoprene derived peroxy radicals (6%), and terpene derived peroxy radicals (1%). A good correlation between model and field measurements for total RO2 for most of the selected stations suggests that they are appropriate background sites as the atmospheric processes occurring at these stations are representative of the chemistry taking place within the entire model grid square in which they are located. The seasonality exhibited by RO2 has been studied, with well-defined cycles (highest in summer and lowest in winter) seen in both hemispheres. Peroxy radical-water complexes, whilst not represented using Chemical Transport Models (CTMs) previously, are postulated to perturb RO2 chemistry. The significance of water clusters (RO2.H2O) is investigated using the STOCHEM-CRI model and reveals that at 300 K the proportion of RO2 participating in complexation with water is approximately 12% in the tropics. Isoprene derived radicals are the most strongly bound of RO2 species investigated and their degree of complexation at approx. 300K far surpasses that of the generic peroxy radicals by 3–5%. At higher altitudes (approx. 8 km) characterized by sub-ambient temperatures, the fraction of RO2.H2O complex that can exist is approximately 17% in the upper troposphere above Mace Head (Northern Hemisphere), 14% above Cape Grim (Southern Hemisphere), and 8% above Mauna Loa (Tropics).

Hybrid search for the optimal PMU placement problem on a power grid

With increasing global concerns regarding energy management, the concept of the smart grid has become a particularly important interdisciplinary research topic. In order to continually monitor a power utility system and efficiently observe all of the states of electric nodes and branches on a smart grid, placing PMUs (phasor measurement units) at selected nodes on the grid can monitor the operation conditions of the entire power grid. This study investigates methods for minimizing the high installation costs of PMUs, in order to monitor the entire system using a set of PMUs according to the power observation rules. Notably, this problem of monitoring a power grid can be transformed into the OPP (optimal PMU placement) problem. The objective is to simultaneously minimize the number of PMUs and ensure the complete observability of the whole power grid. This combinatorial optimization problem has been shown to be NP-complete. In this paper, we propose a hybrid two-phase algorithm for this problem. The first phase of the algorithm quickly identifies a set of candidate locations of PMUs based on a graph-theoretic decomposition approach for the power domination problem in tree-type graphs. Then, we use a local search heuristic method to derive the minimum number of PMUs in the second phase. In addition to the practical model, this study also considers the ideal model, in which all load nodes are assumed to be zero injection. The numerical studies on various IEEE power test systems demonstrate the superior performance of the proposed algorithm in both the models in regard to computational time and solution quality. In particular, in the ideal model, the number of PMUs required for the test systems can be significantly reduced. We also provide theoretical lower bounds on the number of installed PMUs in the ideal model and show that the derived solution can achieve the bound of the test systems.

Puzzle—Shedding Light on Higher Dimensions

Lights Out puzzles have been a popular computer pastime since the eighties. They consist of a grid of cells with each cell in one of two states, lit or unlit. When a cell is clicked, then that cell and its immediate neighbors toggle between lit and unlit. The objective is to identify the set of cells that must be clicked such that the entire grid is lit. Many variations on this theme devised by Jaap Scherphuis are at www.jaapsch.net/puzzles/lights.htm and one particularly interesting twist is at www.jaapsch.net/puzzles/java/lograph/lographapp.htm . This page implements, in the form of a Java applet, a set of tools to allow the creating, editing and playing of Lights Out puzzles on graphs. The nodes of the graph represent cells, and edges join any two cells that are considered neighbours. I show how to formulate Lights Out puzzles as integer programs and produce solutions using GLPK and Minisat. These are, respectively, open source software programs to solve Integer Programs and Satisfiability problems and are available within the GUSEK environment which may be downloaded from http://gusek.sourceforge.net/gusek.htm.

Designing Broadband over Power Lines Networks Using the Techno-Economic Pedagogical (TEP) Method – Part II: Overhead Low-Voltage and Medium-Voltage Channels and Their Modal Transmission Characteristics

Based on the techno-economic pedagogical (TEP) method proposed in [1] that is suitable for designing Broadband over Power Lines (BPL) networks in transmission and distribution power grids, this paper examines the broadband potential of overhead low-voltage/broadband over power lines (LV/BPL) and medium-voltage/broadband over power lines (MV/BPL) networks. In this paper, on the basis of the set of linear simplifications and techno-economic metrics already presented in [1], TEP method demonstrates to undergraduate electrical and computer engineering (ECE) students the behavior of overhead LV/BPL and MV/BPL networks in terms of their modal transmission characteristics when different overhead LV/BPL and MV/BPL topologies occur. The contribution of this paper is four-fold. First, the factors influencing modal transmission characteristics of overhead LV/BPL and MV/BPL networks are investigated with regard to their spectral behavior and end-to-end channel attenuation. Second, the impact of the multiplicity of branches at the same junction is first examined. In the light of cascaded two-way power dividers, TEP method is extended so as to cope with more complex BPL topologies offering a new simplified and accurate circuital approximation. Third, apart from the broadband transmission characteristics of the entire overhead distribution power grid, a consequence of the application of TEP method is that it helps towards the intraoperability/interoperability of overhead LV/BPL and MV/BPL systems under a common PHY framework in the concept of a unified distribution smart grid (SG) power network. Fourth, TEP method can be demonstrated to undergraduate ECE students as case study in order to stimulate their interest for Microwave Engineering and Circuit/System Engineering courses. Citation: Lazaropoulos, A. (2015). Designing Broadband over Power Lines Networks Using the Techno-Economic Pedagogical (TEP) Method – Part II: Overhead Low-Voltage and Medium-Voltage Channels and Their Modal Transmission Characteristics. Trends In Renewable Energy, 1 (2), 59-86. doi: 10.17737/tre.2015.1.2.006

Comprehensive Modelling and Small Signal Stability Analysis of RES-based Microgrid

Implementation of power electronic devices has introduced novel challenges in microgrid (MG) operation and control; and hence the condition of power electronic devices should be monitored for stable operation of the entire grid. This paper presents detailed small signal model of the MG based upon Renewable Energy Resources (RESs), focusing on the dynamic behavior of power electronic devices and associated controllers. Variations on inverter modulation indices and boost converter duty cycles were applied to observe small signal stability performance of the MG. Eigenvalues and participation factor analysis were presented to identify weak modes and stability margin. Analysis of eigenvalue loci shows motion of low frequency loci toward the right-half complex plane as the parameters of power electronic devices varied. More severe oscillatory behavior was experienced when fluctuation occurred at the grid-side inverter, which indicates fast degradation of damping and stability margin. The presented work contributes to help utilities in designing a stable MG for seamless integration of renewable energy into power systems.