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Available transfer capability (ATC) is an important measurement index to evaluate the security margin of interconnected power grids and serve as a reference for the transmission right transaction. In modern power systems, ATC is affected by the transmission network topology, renewable power output uncertainty, and load demand uncertainty. Traditional works usually model the power source-load uncertainty by using robust optimization, interval optimization, or chance-constraint optimization, which cannot fully reflect the probabilistic distribution of the daily source-load uncertainty. This paper proposes an ATC assessment methodology based on the typical stochastic scenarios of renewable output and load demand of multiarea power systems. Furthermore, the conditional generative adversarial network (CGAN) algorithm is adopted to generate and select representative scenario sets based on historical raw data, which can fully reflect the usual operating condition of a system with high renewable energy penetration. The scenario set that is fed into the ATC assessment model can fully characterize the impact of source-load uncertainty on daily ATC. Finally, the proposed method is verified by a modified three-area IEEE 9-bus system and a real-world provincial power system. [ABSTRACT FROM AUTHOR]

Unbalancing the real power in power system leads to fluctuation in system frequency which can cause the several negative effects on the performance and reliability of the interconnected power system. Therefore, to deal with this, the load frequency control (LFC) of a three-area asymmetric thermal power system integrated with a solar thermal power plant (STPP), a realistic dish-stirling solar thermal system (DSTS), and an accurate high voltage direct current (HVDC) link are presented in this work. For the suggested system, a novel cascade controller called fractional-order proportional-integral and integral-double-derivative with filter (FOPI-IDDN) is designed. By minimising a newly proposed performance index called the HPA-ISE and adjusting the controller and other system model parameters using a metaheuristic method called the crow search algorithm (CS). When comparing the system dynamics, it was found that the suggested FOPI-IDDN controller outperformed the FOPI, PIDN, and FOPIDN controllers. The findings of this study show that HPA-ISE shows approximately 30% and 60% improvements in settling time (ST) and peak overshoots (POS) for frequency response, and 32% and 18% improvements for the tie power responses in terms of ST and POS over ISE criteria. Also, studies on different area capacity ratios have shown that a system connected to a greater capacity ratio operates better. The realistic DSTS system with fixed and recurring insolation in area 1 and area 2 outperforms the others, according to experiments using different DSTS insolation. Also, it is discovered that the parallel AC-AHVDC link study is superior to the AC and HVDC connection research. Moreover, it seems from the sensitivity study that the CS-optimized FOPI-IDDN controller improvements obtained under normal settings are consistent across a wide range of changes. [ABSTRACT FROM AUTHOR]

Oscillations are an intrinsic phenomenon in interconnected power systems, leading to steady-state stability, safety decline, transmission power limitation, and electric power systems' ineffective exploitation by developing power systems, particularly by connecting these systems to low-load lines. In addition, they affect the economic performance of the systems. In this study, PSS2B power system stabilizers and TCSC compensators are used to improve the stability margin of power systems. In order to coordinate TCSC compensators, the MOPSO multiobjective algorithm with integral of the time-weighted absolute error (ITAE) and figure of demerit (FD) objective functions was used. The MOPSO algorithm optimization results are compared with nondominated sorting genetic algorithm (NSGAII) and multiobjective differential evolution (MODE) algorithms. The optimization results indicated a better performance of the proposed MOPSO algorithm than NSGAII and MODE. The simulations were iterated in two scenarios by creating different loading conditions in generators. The results indicated that the proposed control system, where the coordination between PSS2B power system stabilizers and TCSC compensators using the MOPSO algorithm, is better than power systems in which PSS2B Stabilizers or TCSC compensators are utilized solely. All criteria, e.g., ITAE, FD, maximum deviation range, and the required time for power oscillation damping in hybrid control systems, have been obtained. This means more stability and accurate and proper performance. [ABSTRACT FROM AUTHOR]

Electricity has become one of the most essential components of establishing a quality standard of living in any country. Consequently, considerable work has been focused on designing a sophisticated load frequency control (LFC) system. However, in light of limited resources and real-world challenges, computationally based control algorithms that are more effective and less expensive remain critically needed. Thus, this paper employs a modified honey badger algorithm (HBA) in conjunction with the concepts of Lévy flight and inertia weight to optimize the parameters of a new cascaded two-degree-of-freedom fractional-PID structure coupled with a proportional derivative (2DOF + FOPIDN)-PD controller to solve LFC problems in an interconnected power system (IPS) comprising conventional and renewable energy sources (RES). The proposed control technique is applied to a two-area IPS under diverse load conditions and in the presence of nonlinear elements and electronic devices. The proposed method is evaluated with respect to a range of performance metrics, such as settling time, undershoots, and error criteria values. The collective performance of the established control scheme indicated that the suggested control approach provides excellent reliability under various load condition scenarios, sensitivity tests, and perturbations, proving the system's efficacy and dependability. [ABSTRACT FROM AUTHOR]

This study introduces a resilient frequency controller for nonlinear interconnected power systems to counteract endogenous/exogenous system disturbances. A neural network-based observer (NNO) is intended to estimate lumped system disturbances, such as unmodelled dynamics and unknown disturbances. The estimated NNO's output is incorporated with a second-order sliding mode controller (SOSMC) to minimize chattering in the control effort and improve the nominal performance of the undertaken plant. The design parameters of SOSMC have been optimally identified by applying Harris hawk optimization (HHO), exercising integral error-based objective function. HHO has demonstrated superior tuning capabilities than other well-known optimization methodologies in terms of convergence rate and transient measurements of system outputs. The asymptotic convergence of estimated error and overall stability of the system has been established employing the Lyapunov argument. System outputs are compared with the results reported in the literature to validate the efficacy of the proposed resilient frequency controller. Presented results showcase the mastery of the applied NNO-based SOSMC over its counterparts in weaker chattering, fast disturbance rejection, and a high degree of robustness against endogenous/exogenous disturbances. [ABSTRACT FROM AUTHOR]

In this study, we study the load frequency control (LFC) problem for interconnected multiarea power systems (IMAPSs) with quantization and actuator failure. To effectively reduce the amount of data in the channel, input signals will be quantized before being transmitted from a controller to a system through the digital communication channel. To reveal the asynchronous phenomenon between the original plant and LFC with actuator failure, a hidden semi-Markov model is formulated. In addition, the stability of the jump system under network attack is discussed. On the basis of the Lyapunov theory, sufficient conditions are derived to ensure the stochastic stability of IMAPSs. Finally, the validity of the theoretical results is tested via a simulation example. [ABSTRACT FROM AUTHOR]

Modern interconnected power grids are a critical target of many kinds of cyber‐attacks, potentially affecting public safety and introducing significant economic damages. In such a scenario, more effective detection and early alerting tools are needed. This study introduces a novel anomaly detection architecture, empowered by modern machine learning techniques and specifically targeted for power control systems. It is based on stacked deep neural networks, which have proven to be capable to timely identify and classify attacks, by autonomously eliciting knowledge about them. The proposed architecture leverages automatically extracted spatial and temporal dependency relations to mine meaningful insights from data coming from the target power systems, that can be used as new features for classifying attacks. It has proven to achieve very high performance when applied to real scenarios by outperforming state‐of‐the‐art available approaches. [ABSTRACT FROM AUTHOR]

Summary: This paper studies the distributed load frequency control problems for the multi‐area interconnected power system in smart grid. Compared with current results, we develop a new model transformation for traditional interconnected systems with unknown communication time delays and uncertainties. The load frequency control problem becomes the state synchronization problem of multi‐agent system (MAS) consisting of linear double‐integrator system with uncertainties and delays. Then, the H∞ distributed controller is designed based on the new MAS model, which weakens the impact of communication delays, parametric uncertainties, and load disturbance. Meanwhile, the proposed distributed controller only needs its neighbors' information and some rough information about the communication network to achieve the frequency's synchronization. In addition, the power flow in the power system can achieve the power scheduling and peak regulation with the changes of each area's load, which can cause unacceptable frequency deviation. The switching topologies are used to express this new power flow distribution. The corresponding distributed controllers are designed to achieve the frequency's synchronization. Finally, simulation result shows the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

In recent years, the development of renewable energy sources (RESs) and their integration with the conventional power network have increased significantly. Due to the power grid transformation brought about by the large penetration of power electronics converter‐based RESs such as wind and solar photovoltaic (PV), the operation and control of the interconnected power system has become a challenging task with respect to sustaining its stability and reliability. Power systems are confronted by several new stability issues because the dynamic behavior of converter‐interfaced renewable sources differs from conventional generation. In this respect, static synchronous compensator (STATCOM), a shunt connected flexible AC transmission system (FACTS), is recognized as a fundamental solution for maintaining power system stability. This paper presents a thorough and state‐of‐the‐art review of STATCOM control in wind‐ and/or PV‐interfaced power systems for enhancing system performance by addressing key stability issues related to rotor angle stability, voltage stability, and resonance stability. A comprehensive analysis of various control techniques of STATCOM based on conventional, adaptive, nonlinear, predictive, robust, and coordinated control and soft computing techniques is provided. Furthermore, the function of the grid‐side converter of the wind/PV plant as a STATCOM is also evaluated. Finally, the shortcomings of existing research are highlighted, current control challenges are presented, and several topics for future research are suggested. This paper provides researchers the opportunity to consider the current state of research and develop new control schemes for STATCOM to further improve the stability of modern power grids. [ABSTRACT FROM AUTHOR]

This study investigates the observer-based sliding mode load frequency control for multiarea interconnected power systems under deception attack. By introducing the observer and combining it with the system state equation, the expression of the system error is obtained. A sliding mode surface is proposed to make sure the state of the systems to be stable. Then, the state equation of the system under sliding mode control is derived. The asymptotic stability of the whole system is proved by using the linear matrix inequality (LMI) technique and Lyapunov stability theory. Furthermore, a sliding mode control law is proposed to ensure that the attacked power system can reach a stable position. Numerical simulation results are presented to support the correctness of the results. [ABSTRACT FROM AUTHOR]

Summary: The doubly fed induction generators based wind power plant is extensively used as a renewable energy source; however, their integration with interconnected power systems may cause equal challenges as well. Since such WPPs are decoupled from the grid frequency to operate at maximum power point tracking, hence they cannot participate in effective load frequency control and cause severe deterioration in the frequency regulation of the nonlinear IPS. To address these issues, this article proposes a novel dual‐layered tilt fuzzy control structure (DLTFCS), which comprises of a fuzzy tilt integral derivative with a filter as the first layer working in coherence with a fractional order proportional derivative controller as the second layer, together with an inertial frequency support scheme for WPP. The DLTFCS is developed with an intention of efficient handling of nonlinearity and parametric uncertainty of considered IPS in the presence of WPP. Further, a curated hybrid objective function is also proposed, which consists of a weighted combination of integral of time‐weighted absolute error and oscillatory measure with the help of an analytical hierarchy process and is optimized by a recently devised salp swarm algorithm. The control performance of the proposed controller has been validated by extensive simulation studies under various scenarios ranging from system parametric variations, uncertainties in generation rate constraint, and governor deadband to significant variations in wind penetration levels. Extensive comparative studies suggested that the proposed control structure provides superior performance over fractional order proportional integral derivative (FOPID) and Fuzzy FOPID controller. [ABSTRACT FROM AUTHOR]

Summary: Hydro power plants are in general more stable to the load demands and thus the change in frequency can be easily controlled. Whereas in multi‐source interconnected power system the stability of the system is marginal. In certain conditions the system is also unmeasurable to implement the load frequency control. Linear Quadratic Regulator with output feedback design forms a familiar optimal choice to tackle this problem, but the technique is dependent on the choice of the weighting matrices Q and R for the performance index. Particle swarm optimization technique is commonly used in power system applications for obtaining the weighting matrices. In this paper, an output feedback‐based LQR‐PID technique is used to obtain an improved response for the multisource systems. Due to integral action, the steady‐state value achieved for the change in frequency is minimized. In addition, if the system is unmeasurable LQR technique cannot be applied, in the literature, Linear Quadratic Gaussian is used for the same. Here a balanced truncation model order reduction is used on the original system to convert it to a measurable system. In addition, a comparative analysis is included to highlight the efficacy of the proposed control technique. [ABSTRACT FROM AUTHOR]

Summary: Recently, there has been a growing trend of large proliferation of electric vehicles (EVs) due to its various merits like minimum emission of greenhouse gases, high‐energy efficiency, less maintenance, cost, and so on. Electric vehicles are now seen as an environment friendly and cost effective alternative to the fuel vehicles. This article presents an effective load frequency control of a multi‐area interconnected power system connecting EV fleets along with diversified sources such as Archimedes wave energy conversion (AWEC), geothermal power plant, wind power plant turbine generator, hydro power plant, and thermal power plant. A cascaded controller, combination of tilt integral derivative filter (TIDN) and 1+proportional‐integral (1+PI) (ie, TIDN‐(1+PI)), has also been proposed in this article as a secondary controller to improve the system performances. The real‐time simulation of the considered power system has been effectually executed under different scenarios, using OPAL‐RT's digital simulator. The result shows that the proposed TIDN‐(1+PI) controller along with EV fleets are capable to significantly minimize the frequency and tie‐line power oscillations rapidly and it also provides better dynamic performance of the system as compared to other conventional controllers such as integral, proportional‐integral and so on. In addition, variable and irregular AWEC power, load disturbances in all areas, and multiple nonlinearities have been considered to study the effect of EV fleets in the proposed system. Also, stability of the system has been studied by using Eigen value analysis method. [ABSTRACT FROM AUTHOR]

Chaotic oscillation will occur in power system when there exist periodic load disturbances. In order to analyze the chaotic oscillation characteristics and suppression method, this paper establishes the simplified mathematical model of the interconnected two-machine power system and analyzes the nonlinear dynamic behaviors, such as phase diagram, dissipation, bifurcation map, power spectrum, and Lyapunov exponents. Based on fractional calculus and sliding mode control theory, the fractional-order hyperbolic tangent sliding mode control is proposed to realize the chaotic oscillation control of the power system. Numerical simulation results show that the proposed method can not only suppresses the chaotic oscillation but also reduce the convergence time and suppress the chattering phenomenon and has strong robustness. [ABSTRACT FROM AUTHOR]

Summary: In this paper, load frequency control of photovoltaic (PV)‐thermal‐thermal interconnected three area power system is proposed with fuzzy gain scheduling controller. Grid‐connected PV power system has quick rising annual rate and is rapidly becoming a significant part of the energy balance in the power systems. Reduction in the PV modules cost increases the application of PV. In recent days, increase in load demand necessitates the interconnected power systems. Power quality concerning frequency plays a major role in life and efficiency of the load. The fuzzy logic controller is an efficient controller to deal with the unknown data; in the LFC, the load demand is unpredictable; hence, fuzzy is applied for LFC in this analysis. Proportional integral (PI) controller plays a significant role in real‐time LFC. Therefore, in this article, fuzzy gain scheduling controller is proposed to tune gains of PI controller to improve performance of interconnected power systems. To validate the performance of proposed system, it is compared with the conventional PI controller‐based LFC. The entire system is analyzed using Matlab with various loads. [ABSTRACT FROM AUTHOR]

Summary: During the past few decades, frequency regulation of combined cycle gas turbine (CCGT) has become an interesting issue of research. A larger power system model experiences many challenges when base‐loaded CCGT unit is incorporated in it. This article presents the load frequency regulation of CCGT model in conjunction with thermal units in an unequal 3‐area interconnected system. The control strategy of CCGT plant includes temperature and air flow controllers that are designed on the basis of minimization of area control error. The main drive of proposed control strategy is to successfully tackle the system dynamics during step and realistic load disturbances. The eigenvalues of proposed system commensurate with dynamic stability. A new metaheuristic algorithm known as stochastic fractal search has been applied for simultaneous optimization of classical controller (proportional [PI], proportional‐integral [PI] and proportional‐integral‐derivative [PID] gains, and other parameters such as governor speed regulation parameter [Ri], frequency bias [Bi]). Comprehensive simulations are performed to ensure stable system dynamics with easier and cheaper realization of governor, and higher values of Bi in respective areas and robustness of stochastic fractal search optimized PID controller. [ABSTRACT FROM AUTHOR]

Due to the global concerns regarding the climate change, integration of renewable energy sources is considered as a mitigation approach in electric power generation. This requires advanced frequency and voltage control methodologies to overcome the challenges especially in microgrids. This paper presents a 2-step frequency and voltage control methodology for microgrids with high penetration of variable renewable energy sources. An optimized Proportional-Integral controller is designed for a Superconductor Magnetic Energy Storage System to minimize the transient frequency deviations. In cases that the Superconductor Magnetic Energy Storage System cannot stabilize the microgrid frequency in the isolated mode, the microgrid controller activates the next level of the frequency control. In the second level, an intelligent fuzzy-logic frequency controller is designed to adjust controllable loads, controllable generation units as well as perform load shedding. In the interconnected mode, the microgrid controller is able to activate the second level to contribute to the system frequency control. Finally, an intelligent fuzzy-logic voltage controller, realized through distribution static synchronous compensator, is devised to control the voltage magnitude of the main feeders of the microgrid. In this work, a real-time operation algorithm for frequency as well as voltage control is proposed and has been tested by set of simulations on a low voltage benchmark network. [ABSTRACT FROM AUTHOR]

In this paper, a new wide area neural network-based method is presented for the accurate detection of necessity and the time of controlled islanding execution in large interconnected power systems. By performing coherency analysis at different conditions, the initial coherent groups of the network are determined. To account different stability margins between areas at different conditions and network topologies, we introduced the new parallel neural network (P-NN) structure. The proposed P-NN consists of different individual recurrent neural networks between each of adjacent initial groups. The P-NN is trained with respect to selected wide area signals and generated database through comprehensive stability studies. After the online detection of possible asynchronous oscillations and the corresponding final coherency determination, the alarm signal is sent to the designed P-NN to investigate the network stability between initial groups in real time. The proposed method is applied to New England 39- and 118-bus power systems at different cases and is compared with another intelligent method. It is shown that the proposed method is able to detect islanding necessity and related islands accurately for different disturbances. The speed of the islanding detection, as an important aspect in intelligent controlled islanding, is increased by the proposed method. This will in turn help the system keep stability. In addition, the proposed method could distinguish large stable swings from unstable ones in different contingencies. [ABSTRACT FROM AUTHOR]

A framework for interconnected multi-microgrids (MMGs) optimal power dispatch at smart distribution grids is introduced with network uncertainties. In proposed work, microgrids (MGs) not only exchange power with main grid, but also operate in interconnected mode to increase network reliability. For each small scale energy resources (SSER) and load, a probabilistic model is applied to determine the optimal power sharing of interconnected MGs with minimum operating cost. The power interchange between MGs and the main grid is regulated based on the total operating cost regarding the sold or purchased power either by MGs or by main grid. The stochastic analysis of network variables is done considering optimization constraints and explained as probability distribution function (PDF) and cumulative distribution function (CDF). The imperialist competitive algorithm (ICA) and particle swarm optimization (PSO) algorithms are applied to optimize the object function, and obtained results are compared with Monte Carlo simulation (MCS) method. The results confirm that the optimal power sharing between MGs and main grid can decrease the operating cost of the smart distribution networks. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The problem of decentralized impulse controllability/observability for large-scale interconnected descriptor systems with two subsystems by derivative feedback is studied. Necessary conditions for the existence of a derivative feedback controller for the first subsystem of the large-scale interconnected descriptor systems ensuring the second subsystem to be impulse controllable and impulse observable are derived, respectively. Based on the results, a derivative feedback controller for the first subsystem of the large-scale interconnected descriptor systems is constructed easily such that the second subsystem is impulse controllable or impulse observable. Finally, examples are given to illustrate the effectiveness of the results obtained in this paper. [ABSTRACT FROM AUTHOR]

Nowadays, low frequency oscillation has become a major problem threatening the security of large-scale interconnected power systems. According to generation mechanism, active power oscillation of electric power systems can be classified into two categories: free oscillation and forced oscillation. The former results from poor or negative damping ratio of power system and external periodic disturbance may lead to the latter. Thus control strategies to suppress the oscillations are totally different. Distinction from each other of those two different kinds of power oscillations becomes a precondition for suppressing the oscillations with proper measures. This paper proposes a practical approach for power oscillation classification by identifying real-time power oscillation curves. Hilbert transform is employed to obtain envelope curves of the power oscillation curves. Twenty sampling points of the envelope curve are selected as the feature matrices to train and test the supporting vector machine (SVM). The tests on the 16- machine 68-bus benchmark power system and a real power system in China indicate that the proposed oscillation classification method is of high precision. [ABSTRACT FROM AUTHOR]

During the last fewyears generation from renewable energy sources (RESs) has grown considerably in European electrical networks. Transmission system operators are greatly concerned about the impact of RESs on the operational security and efficiency of their networks and more in general of the ENTSO-E interconnected system. Grid codes are to be revised in order to harmonise the rules regarding the connection of RES power plants. A main issue concerns frequency control: frequency is greatly affected by RESs intermittency and its deviationsmust be limited asmuch as possible in order to guarantee a suitable level of power quality. To improve frequency stability, in the future, Grid codes could extend frequency control requirements also to RES units, whereas today they are applied only to conventional power plants. Energy storage systems can be a possible solution to increase the flexibility and performance of RES power plants: they allow generators to modulate their power injections without wasting renewable energy. In this paper, the authors studied the suitability of extending frequency control to RES units integrating them with energy storage systems. In particular, the paper focuses on the impact of frequency control on the storage lifetime by analysing the power charge/discharge in response to real frequency oscillations. [ABSTRACT FROM AUTHOR]

Power systems as one of the key infrastructures play a crucial role in any country's economy and social life. A large-scale blackout can affect all sectors in a society such as industrial, commercial, residential, and essential public services. However, the frequency of large-scale blackouts across the world is not being reduced, although advanced technology and huge investment have been applied into power systems. Given a single blackout, it is possible to analyze the causes with the traditional engineering methods. What we want to do is not to explain the causes of blackouts but to find what are the most critical elements of the power system to improve the resilience of the system itself. As blackout can happen in different load conditions, we do not want a method that depends on the load/generation level. We want a method independent from these factors: This is the structural perspective. When the interconnection between European and Russian power grids will create the largest interconnected power grid throughout the world in terms of the scale, transmission distance, and involved countries, analyzing the vulnerability of a large-scale power grid will be useful to maintain its reliable and secure operation. To analyze the vulnerability of the interconnected power grid, in this article, we first created the interconnected transmission network between continental Europe and the Commonwealth of Independent States (CIS) and Baltic countries; then, the structural vulnerability of the interconnected power grid was analyzed from a topological point of view using our proposed extended topological method, which incorporates some electrical engineering characteristics into complex network methodology. We found that these power grids of continental Europe, the Baltic states, and the CIS countries can benefit from the interconnection because the interconnected power grid can not only improve the overall network performance of these power grids in the Baltic states and the CIS countries but also increase their structural robustness. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY Sub-synchronous resonance (SSR) is a frequent adverse phenomenon in series-compensated lines, threatening either or both mechanical facilities and power system stability. It is widely accepted that flexible AC transmission system (FACTS) can provide an effective solution to relieve the SSR. On the other hand, the advent of distributed FACTS (D-FACTS) technology has led to more economical deployment of the flexible devices in the power system control. This article focuses on verifying the capability of the distributed power flow controller (DPFC) to alleviate the SSR. As a member of the D-FACTS family, the DPFC operates in the same way as the unified power flow controller (UPFC). Compared with UPFC, the DPFC has some advantages like higher control capability, lower price, and more reliability. The DPFC impact on SSR mitigation is interrogated in various case studies, namely, with the SSR damping (SSRD) controller on the series converter, with SSRD controller on the shunt converter and with both simultaneously operating. The best case for SSR mitigation is achieved when the DPFC is supplied with two SSRD controllers concurrently. Simulations are carried out with Power Systems Computer Aided Design/ Electromagnetic Transients including DC (PSCAD/EMTDC) on the Institute of Electrical and Electronics Engineers (IEEE) first SSR benchmark model aggregated with DPFC on the transmission line. Furthermore, a comparison between the SSRD controller on DPFC converters and the supplementary excitation damping controller or the conventional power system stabilizer is also carried out. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An event-triggered scheme is adopted and applied to the design of a centralized wide-area H8 damping controller (WAHDC) of interconnected power systems with external disturbance. Firstly, based on the linearized multimachine system model, the centralized WAHDC with event-triggered scheme design problem is described as time-delay feedback control problem. Then by using Lyapunov functional method and Jensen inequality technique, criteria for stability with an H8 norm bound and for design of the feedback controller are derived. The linear matrix inequality (LMI) is employed to solve the feedback gain. Finally, case studies are carried out based on two-area four-machine power system. Simulations indicate that the proposed WAHDC with eventtriggered scheme can damp the interarea oscillation effectively when the external disturbance is bounded and significantly reduce the number of measured states released to WAHDC. Relationships between event trigger parameter ɑ and dynamic performance, ɑ and network utilization, ɑ and time delay, and ɑ and disturbance rejection level are investigated and results obtained can be used to choose an appropriate event trigger parameter. [ABSTRACT FROM AUTHOR]

Considering the load frequency control (LFC) of large-scale power system, a robust distributed model predictive control (RDMPC) is presented. The system uncertainty according to power system parameter variation alone with the generation rate constraints (GRC) is included in the synthesis procedure. The entire power system is composed of several control areas, and the problem is formulated as convex optimization problem with linear matrix inequalities (LMI) that can be solved efficiently. It minimizes an upper bound on a robust performance objective for each subsystem. Simulation results showgood dynamic response and robustness in the presence of power system dynamic uncertainties. [ABSTRACT FROM AUTHOR]

Interference coordination methods for Evolved-Multimedia Broadcast/Multicast Service (E-MBMS) in Long-Term Evolution Advanced (LTE-A) are presented. In addition, we consider signal space diversity based on Rotation Matrices (RM) known to provide good performance gains over uncorrelated Rayleigh fading channels. OFDM/OFDMA systems can make the use of RM very attractive both for single andmultiple antenna transmissions. In this paper, OFDM/OFDMA signals based on LTE parameters are combined with RM, MIMO, Turbo, or LDPC codes.We have considered different types of receivers, namely, we used an MMSE (Minimum Mean Squared Error) equalizer and a Maximum Likelihood Soft Output criterion (MLSO). Frequency, signal, and space diversity gains are evaluated for different spatial channel models (SCM) based on ITU multipath propagation channels. Different adaptive frequency reuse and schedulers are considered to evaluate the E-MBMS spectral efficiency at the cell borders. [ABSTRACT FROM AUTHOR]

Summary: This paper focuses on automatic generation control (AGC) in deregulated environment for the multiarea interconnected power system. Each area consists of different kind of generating sources like thermal, hydro, and gas, each having different characteristics with physical constraint likes governor dead band and generation rate constraint. Loads are divided among different generator using the concept of economic load dispatch. The AC/DC links has been installed in all areas as well as unified power flow controller (UPFC) in tie lines to mitigate the effect of oscillation and to improve the system response. Thus, a more systematic and synchronized control of AGC with UPFC and AC/DC links has been proposed. Small signal stability of each area has been analyzed for finding out the oscillation states of the studied system. The proposed controller is optimized through Fruit Fly Algorithm, and its promising results reveal that the proposed controller is more efficient and effective in all different power transaction modes of restructured scenario. [ABSTRACT FROM AUTHOR]

Summary: This paper presents a new algorithm to avoid cascading tripping of interconnected transmission lines caused by maloperation of zone 3 distance relay during major power system disturbances. Blocking of zone 3 distance relay and the application of static var compensator controllers are the 2 corrective actions that proposed algorithm use to protect the power system from cascade tripping. Distance relay zone 3 blocking is achieved using real‐time information about the balance between generation and load in each area of the power system. However, the static var compensator controller allows injecting, rapidly and efficiently, necessary reactive power in the system to mitigate the disturbance development during the blockage of the distance relay protection. Results of dynamic simulation on 400 kV Turkish transmission system, using SECRE software, are presented to demonstrate the effectiveness of the proposed algorithm. Simulation results clearly indicate that the use of this algorithm can improve reliability of zone 3 distance relay operation, enhance the stable operation of power system, and can limit the spread of cascading outages during wide‐area disturbance. [ABSTRACT FROM AUTHOR]