Fuzzy Load Research Articles

Decentralized Periodic Dynamic Event-Triggering Fuzzy Load Frequency Control for Multiarea Nonlinear Power Systems Based on IT2 Fuzzy Model

Decentralized Periodic Dynamic Event-Triggering Fuzzy Load Frequency Control for Multiarea Nonlinear Power Systems Based on IT2 Fuzzy Model

Stability and Stabilization for T–S Fuzzy Load Frequency Control Power System With Energy Storage System

Stability and Stabilization for T–S Fuzzy Load Frequency Control Power System With Energy Storage System

Event-Triggered T-S Fuzzy Load Frequency Control With Variable Probabilistic Release for Renewable Energy Integrated Power Systems

Event-Triggered T-S Fuzzy Load Frequency Control With Variable Probabilistic Release for Renewable Energy Integrated Power Systems

Fuzzy correlational analysis for dynamic consolidation of virtual machines in cloud computing environment

This theoretical research in fuzzy correlation analysis integrates data uncertainty analysis by measuring the strength of the linear relationship restricted to two fuzzy sets. As the relevant contribution to this research area, this paper presents the axiomatic definition of the n-dimensional generalized fuzzy correlation coefficient (nGCC), assigning to n input fuzzy sets an output value in the interval [−1,1]. Thus, the properties of general overlap functions and fuzzy negations are studied, discussing binary non-normed restricted dissimilarity functions, and the n-dimensional non-normed conjunctive functions. This study provides new methods for the n-dimensional generalized fuzzy correlation coefficient analysis, regarding their applications in solving multi-criteria and decision-making problems founded on fuzzy logic extensions. The n-dimensional non-normed conjunctive aggregation functions are also introduced, as range domain extensions from [0,1] to [−1.1], covering the interpretation of negative to positive variable associations. The proposal correlation analysis promotes a better evaluation and data selection even when more than one algorithm is applied to evaluate the reduction methods in the defuzzification process based on Interval-valued Fuzzy Logic. We also investigate the relevance to determine a reliable result from the fuzzy inference system based on the nGCC methodology. This correlation methodology applied to the Interval Fuzzy Load Balancing for Cloud Computing (Int-FLBCC) model contributes as a flexible approach for virtual machines dynamic consolidation enabling improvements in resource usage and power efficiency, improving the computational system’s energy efficiency. So, the nGCC methodology extends the Int-FLBCC model by adding other degrees of reliability to the results obtained with diverse evaluations through n-dimensional generalized fuzzy correlation coefficient expressions, exploring average aggregations as arithmetic and exponential means and the median operator.

Optimal self-tuning fractional order fuzzy load frequency control considering sustainable energy sources and electric vehicle

Considering uncertainties associated with sustainable energy sources in modern power systems, one of the main obstacles for load frequency control (LFC) is that various publications regard the parameters of FOPID controllers as fixed after optimisation. To tackle this challenge, an adaptive control structure may be a viable option for LFC. In this paper, in a two-zone hybrid power system that includes a thermal power plant, green energy sources, fuel cells, and plug-in electric vehicles, an optimal self-tuning fractional order fuzzy (OSTFOF) controller for LFC is proposed. Pathfinder algorithm (PFA) has been utilised for optimal tuning of parameters of the OSTFOF controller, including the upper bands of output membership functions, the input scaling factors, and the order of integral and derivative operators. In the proposed controller, the values of proportional, integral, and derivative gains are adaptively obtained. In the thermal power plant, non-linear factors, such as governor dead band (GDB) and generation rate constraint (GRC), are considered. Four different scenarios have been considered to evaluate the performance of the proposed OSTFOF controller, and results have been compared with PI, PID, and FOPID controllers. The simulations’ results indicate the excellent performance indices of the suggested OSTFOF controller compared to other controllers.

Sampled Memory-Event-Triggered Fuzzy Load Frequency Control for Wind Power Systems Subject to Outliers and Transmission Delays.

This study is devoted to event-triggered fuzzy load frequency control (LFC) for wind power systems (WPSs) with measurement outliers and transmission delays. Due to the integration of wind turbine (WT) with nonlinearity, the T-S fuzzy model of WPS is established for stability analysis and controller design. To mitigate the network burden, a new sampled memory-event-triggered mechanism (SMETM) related to historical system information is presented. It has the following two merits: 1) the utilization of continuous memory outputs over a given interval is useful to reduce the information loss in the period of samples and the redundant triggering events induced by disturbances and noises and 2) an extra upper constraint is added in the triggering condition to generate a new event only when the error signal belongs to a bounded range, thus, the false events caused by measurement outliers can be differentiated out and then be dropped. By representing the memory signal with transmission delay as a time-varying distributed delay term, a T-S fuzzy time-varying distributed delay system is built up to model the H∞ LFC WPS. With the help of the Lyapunov method and the integral inequality relying on distributed delay, some criteria are derived to solve the triggering matrix and fuzzy controllers. Finally, the merits of the proposed SMETM are tested by simulation results.

A new paradigm for intelligent status detection of belt conveyors based on deep learning

All-round visual monitoring of conveyor belt running status is an important component of the belt conveyor operation and maintenance system. Intelligent analysis methods will help improve the detection in real-time and effectiveness and help make reasonable decisions. Aiming at the current situation that the existing technology cannot achieve integrated detection, this paper proposes a new conveyor belt running status monitoring paradigm based on deep learning for the first time. By grafting the segmentation network into the target detection network Yolov5, the integrated detection of various tasks, including fuzzy load measurement, deviation status detection, large foreign objects, and belt damage detection, etc., is realized in a real sense. Experiments show that the proposed method balances detection accuracy and speed well, with a detection accuracy of up to 97%, a segmentation accuracy of up to 100%, and a detection speed of up to 90 frames per second (FPS). The proposed integrated detection work is of great significance for improving the intelligent analysis capability of the operation and maintenance system, thereby ensuring the safe and efficient operation of the transportation system. Our source dataset is available at https://github.com/zhangzhangzhang1618/dataset_for_belt_conveyor/tree/master.

Event-Based Distributed Fuzzy Load Frequency Control for Multiarea Nonlinear Power Systems With Switching Topology

This article investigates the event-based distributed fuzzy load frequency control approach for nonlinear interconnected power systems under a switching topology. Specifically, nonlinear factors and uncertain parameters existing in turbine and governor dynamics are modeled and analyzed under the interval type-2 fuzzy method. New memory-based adaptive event-triggered mechanisms, whose directions and threshold parameters are dynamically updated based on the output change trend and relative output error of multiple memories, are proposed to further save network energy. Aiming at communication topology changes in multiarea power systems, a novel switched control system is established by introducing a time-varying communication matrix. Then, the system’s asymptotic stability is ensured by the piecewise Lyapunov–Krasovskii method. Furthermore, to further relax stability conditions, slack matrices are considered with the boundary information of membership functions. Finally, three-area power systems are shown to demonstrate the effectiveness of proposed distributed load frequency control strategies.

A Parallel Fuzzy Load Balancing Algorithm for Distributed Nodes Over a Cloud System

Cloud Computing is an IT organization concept that places the Internet at the heart of business activity, allowing it to use hardware resources. In recent years, Load Balancing has been an active area of research, and has played a very important role in the case of the Cloud environment. There is a wide range of improvements in this arena. In this paper, we propose a new Load Balancing algorithm, based on the weights of the nearest servers in the cloud platform. We use the fuzzy logic to represent the weight of the different nodes. Moreover, we implement separate requests in parallel, and use a token to dispatch tasks efficiently. The several scenarios in this paper are considered for experimentation and compare the result of existing Round Robin, Throttled Load Balancing, Equal Spread Load and proposed algorithm .The experiment results show that this approach improves the Load Balancing process effectively in terms of overall response time, data center processing time, total virtual machine cost, and total data transfer cost.

Fuzzy-Swarm Intelligence-Based Short-Term Load Forecasting Model as a Solution to Power Quality Issues Existing in Microgrid System

Load demand is highly stochastic and uncertain. This is because it was highly influenced by a number of variables like load type, weather conditions, time of day, the seasonality factor, economic constraints, and other randomness effects. The loads are categorized as holiday loads (national and religious), weekdays, and weekend days. The nonlinearity and uncertain characteristics of electrical load in a microgrid are one of the major sources of power quality problems in a microgrid system, and they can be handled using an accurate load forecast model. The fuzzy load prediction model can effectively handle these nonlinearity and uncertainty characteristics to have an accurate load forecast, but the main challenge with this model is its inability to accommodate a large volume of historical load and weather information when the membership function of the input and output fuzzy variables and the number of the fuzzy rules are tremendous. The swarm intelligence load forecast model based on particle swarm optimization algorithms can improve the limitations of the fuzzy system and increase its forecasting performance. The parameters of time, temperature, historical load, and error correction factors are considered as the Fuzzy and Fuzzy-PSO model input variables, while the forecasted industrial load is the only output variable. The Gaussian membership function is considered for both the input and output fuzzy variables. A 3-year historical hourly load data of an Ethiopian industrial system is used to train and validate both prediction models. The mean absolute percentage error (MAPE) is used to evaluate the performance of these prediction models. The Fuzzy-PSO load prediction model shows results that have superior performance to the fuzzy-alone load prediction results.

A multi‐level data‐driven finite element method in polymorphic uncertainty quantification

AbstractThis contribution explores the ability to conduct polymorphic uncertainty computations within the data‐driven finite element framework. The constitutive equation is replaced by data sets that determine the material behavior, and a fuzzy load is used for the polymorphic approach. To conduct many simulations with the discretized variables and to increase numerical efficiency, the numerical cost is reduced by a multi‐level method.

Research on voltage reactive power optimization considering fuzzy load characteristics

For the distributed load output is uncertain, which leads to the over-limit of voltage and line power, this paper proposes a load representation method based on fuzzy set theory, and establishes a voltage reactive power optimization model based on fuzzy number. The influence of different control equipment on node voltage and reactive power is analyzed. Combined with the sensitivity analysis method, the selection rules of control equipment with heuristic method are developed. A method of Genetic calculation based on fuzzy power flow calculation is presented. Finally, this method is applied to build a 30-node model in Matlab for simulation calculation. The results of the example show that the proposed model and method can accelerate the convergence speed, reduce the solution space and reduce the network loss.

Autonomous Fuzzy Controller Design for the Utilization of Hybrid PV-Wind Energy Resources in Demand Side Management Environment

This work describes an optimum utilization of hybrid photovoltaic (PV)—wind energy for residential buildings on its occurrence with a newly proposed autonomous fuzzy controller (AuFuCo). In this regard, a virtual model of a vertical axis wind turbine (VAWT) and PV system (each rated at 2 kW) are constructed in a MATLAB Simulink environment. An autonomous fuzzy inference system is applied to model primary units of the controller such as load forecasting (LF), grid power selection (GPS) switch, renewable energy management system (REMS), and fuzzy load switch (FLS). The residential load consumption pattern (4 kW of connected load) is allowed to consume energy from the grid and hybrid resources located at the demand side and classified as base, priority, short-term, and schedulable loads. The simulation results identify that the proposed controller manages the demand side management (DSM) techniques for peak load shifting and valley filling effectively with renewable sources. Also, energy costs and savings for the home environment are evaluated using the proposed controller. Further, the energy conservation technique is studied by increasing renewable conversion efficiency (18% to 23% for PV and 35% to 45% for the VAWT model), which reduces the spending of 0.5% in energy cost and a 1.25% reduction in grid demand for 24-time units/day of the simulation study. Additionally, the proposed controller is adapted for computing energy cost (considering the same load pattern) for future demand, and it is exposed that the PV-wind energy cost reduced to 6.9% but 30.6% increase of coal energy cost due to its rise in the Indian energy market by 2030.

Resilient Distributed Fuzzy Load Frequency Regulation for Power Systems Under Cross-Layer Random Denial-of-Service Attacks.

In this article, a novel distributed fuzzy load frequency control (LFC) approach is investigated for multiarea power systems under cross-layer attacks. The nonlinear factors existing in turbine dynamics and governor dynamics as well as the uncertain parameters therein are modeled and analyzed under the interval type-2 (IT2) Takagi-Sugeno (T-S) fuzzy framework. The cross-layer attacks threatening the stability of power systems are considered and modeled as an independent Bernoulli process, including denial-of-service (DoS) attacks in the cyber layer and phasor measurement unit (PMU) attacks in the physical layer. By using the Lyapunov theory, an area-dependent Lyapunov function is proposed and the sufficient conditions guaranteeing the system's asymptotically stability with the area control error (ACE) signals satisfying H∞ performance are deduced. In simulations, we adopt a four-area power system to verify the resiliency enhancement of the presented distributed fuzzy control strategy against random cross-layer DoS attacks. Results show that the designed resilient controller can effectively regulate the load frequency under different cross-layer DoS attack probabilities.

Gain Schedule PI Fuzzy Load Frequency Control for Two-Area Electric Power System

The use of proportional integral (PI) load frequency control (LFC) to ensure the stable and reliable operation of electric power system is practical important. Any imbalance between synchronous generators and consumption loads will cause frequency unstable within the complete power system. The purpose of the load frequency control (LFC) is to keep the power system frequency and the inter-area tie power as near equilibrium point. This article introduces a gain schedule PI fuzzy load frequency control (GLFC) applying to two area electric power system. The GLFC consists of two level control systems, where the PI controller in the conventional form and its parameters are tuned in real time by fuzzy system. A fuzzy rule base is constructed in the form set of IF-THEN that describe how to choose the PI parameters under different operating conditions. The simulation has been conducted in MATLAB Simulink package. The effectiveness of the GLFC is measured by comparison with conventional PI load frequency controller.

Market-Based Integrated Generation Expansion Planning of Electric Power System and District Heating Systems

As the primary heat source in the district heating systems (DHSs), combined heat and power (CHP) units are playing an increasingly significant role in electricity generation. Considering that, this paper innovatively proposes an integral generation expansion planning (GEP) framework, which enables competition to occur among conventional power plants (CPPs) of the GENCOs and CHP units of the DHSCOs. The proposed framework is based on decentralized decision-making which involves an iterative process for simulating the interactions of ISO, GENCOs, and DHSCOs. The combined heat and power dispatch model is reconstructed to determine the LMPs to offer incentives for market participants' investments. The fuzzy load duration curve (FLDC) method is proposed to model the electricity load that would influence the LMPs. In each FLDC state, uncertain load is represented by a fuzzy number. Investment decision-making models of the GENCOs and DHSCOs are formulated as a mixed integer linear programming with fuzzy objectives (MILPFO). A technique is proposed to solve the MILPOF models with the consideration of the risk appetite of the market participants. The examples illustrate the benefits of integrated planning of electric power system and DHSs.

Fuzzy Load Forecast with Optimized Parametric Adjustment Using Jaya Optimization Algorithm

This paper proposes an advanced fuzzy load forecast method optimized by modified Jaya optimization (MJO) algorithm. MATLAB® platform is used to implement the proposed hybrid Fuzzy-MJO load forecasting algorithm and to verify the outperforming features of a Jaya technique over a fuzzy load forecast model. The novel Fuzzy-MJO load forecasting systems uses the day-time and the daily power consumption to efficiently predict the forecast power consumption. The comparative load forecasting results between proposed Fuzzy-MJO with the latest other algorithms are adequately presented. The full week forecast results using proposed hybrid Fuzzy-MJO load forecasting algorithm demonstrates an outperforming superiority, through the various tested cases, regarding to the total and the peak power error in comparison with the fuzzy-based load forecast model.

Design and exploration of load balancers for fog computing using fuzzy logic

This research work presents an exploratory study to find answers for managing traffic and payloads in edge/fog zone of the networks. Initial deployments have shown that edge computing has helped in fine grain customization of services and have produced better experiences for the users. However, at the same time, it also invites challenges such as overload, underload and imbalance in utilization of resources such as bandwidth, time responses, throughput etc. The main reason is highly constrained environment and restricted hardware capabilities of fog devices. The conventional algorithms, that work on finding the best routing paths for distributing and processing tasks, do not suffice with respect to Quality of Service (QoS) parameters of fog zone as their computations become unstable. An alternative approach is considered by adding software defined components, that can help in load balancing and managing the payloads using link analysis at the inter-nodes of cloud and fog zone. In this research work, a fuzzy load balancer is devised using different levels of design and tuning of fuzzy controls. This fuzzy logic based algorithm has been implemented for conducting link analysis as interconnects for managing traffic. The analysis shows that 3-level design is energy efficient for load balancing in fog zone due to reduced number of intervals in fuzzy design, reduced overhead in provisioning and improved responsiveness. Higher levels (5-level and 7-level) lead to creation of redundant fuzzy rules and wastage of resources.

A comparative study and analysis of agent based monitoring and fuzzy load balancing in distributed systems

Load balancing algorithms are designed to achieve efficient resource utilisation in large-scale distributed systems. The primary goal of designing load balancing algorithms is to balance the overall workload among all the nodes in distributed systems to improve the performance. This paper presents an in-depth study and detailed comparative analysis of different load monitoring and balancing algorithms employing fuzzy logic and mobile agents. A detailed qualitative as well as quantitative analysis of algorithmic performances is included. The analytical survey presented in this paper would enable understanding of applications of different algorithms under different computing environments. Furthermore, this paper proposes a hybrid architecture combining fuzzy logic and mobile agents for load balancing and monitoring in distributed systems.

A comparative study and analysis of agent based monitoring and fuzzy load balancing in distributed systems

Load balancing algorithms are designed to achieve efficient resource utilisation in large-scale distributed systems. The primary goal of designing load balancing algorithms is to balance the overall workload among all the nodes in distributed systems to improve the performance. This paper presents an in-depth study and detailed comparative analysis of different load monitoring and balancing algorithms employing fuzzy logic and mobile agents. A detailed qualitative as well as quantitative analysis of algorithmic performances is included. The analytical survey presented in this paper would enable understanding of applications of different algorithms under different computing environments. Furthermore, this paper proposes a hybrid architecture combining fuzzy logic and mobile agents for load balancing and monitoring in distributed systems.