Frequency Load Control Research Articles

Multi-objective design of fractional frequency-load control for hydro-thermal system considering nonlinear models and uncertainty

One of the crucial quantities in the power system problem is frequency, which should never exceed its nominal value. In normal conditions of load changes, the frequency is adjusted by automatic generation control. Still, in the face of special conditions, such as logging of the downstream network from the main network or a significant amount of generated power leaving the circuit, the power imbalance between generation and consumption causes a rapid frequency drop. In this case, the automatic generation control cannot stop the frequency drop, so the frequency tends toward instability. In this paper, to automatically produce a water-thermal system in two zones of discrete and continuous modes, the design of a fractional controller is discussed and investigated in different functional conditions and uncertainties. The proposed NSGA-II multi-objective method is used in this article to optimize each area’s load frequency control parameters for various goals. The ideal response for the entire network will be obtained by modifying these responses using a multi-factor method. This paper defines a multi-zone frequency load control based on time objective functions and eigenvalues. Based on the speed changes for the proposed algorithm and the novel approachfunction method employed in the control design. The simulation performed and analyzed in different working conditions with different comparative criteria has been discussed and investigated. Compared to more contemporary techniques, the simulation results show that the system’s performance is guaranteed. The main successes of the suggested method in comparison to earlier methods have been the reduction of overshoot, undershoot, and settling time.

Analyzing Small-Signal Stability in a Multi-Source Single-Area Power System with a Load-Frequency Controller Coordinated with a Photovoltaic System

The frequency deviation from the nominal working frequency in power systems is a consequence of the imbalance between total electrical loads and the aggregate power supplied by production units. The sensitivity of energy system frequency to both minor and major load variations underscore the need for effective frequency load control mechanisms. In this paper, frequency load control in single-area power system with multi-source energy is analysed and simulated. Also, the effect of the photovoltaic system on the frequency deviation changes in the energy system is shown. In the single area energy system, the dynamics of thermal turbine with reheat, thermal turbine without reheat and hydro turbine are considered. The simulation results using Simulink/Matlab and model analysis using eigenvalue analysis show the dynamic behaviour of the power system in response to changes in the load.

Optimal design of frequency load control system in multi-zone power system using PID-fuzzy controller optimized by bee algorithm

Optimal design of frequency load control system in multi-zone power system using PID-fuzzy controller optimized by bee algorithm

Secure Data Transmission and Trustworthiness Judgement Approaches Against Cyber-Physical Attacks in an Integrated Data-Driven Framework

Threats of cyberattacks have penetrated from disclosing critical user information to destroying/manipulating industrial control systems. Study on data security during network transmission has raised increasing attention in the systems and control community, which is found very necessary and timely in the context of Industry 4.0. In most existing approaches, the protection of the transmitted data from eavesdropping attacks and the detection of malicious integrity attacks are usually carried out separately. In this study, an integrated data-driven framework applicable at the control level is proposed to deal with secure transmission and attack detection simultaneously. In the framework, a secure correlation-based encryption/decryption approach and a trustworthiness judgement approach are proposed. Comprehensive discussions are made regarding the analysis of the sensitivity to attacks, the introduced time delay, and the design degree-of-free. Executable algorithms are presented, corresponding to which hardware is modularized and can work standalone independent from the configuration of the monitoring and control systems or any third-party authentication agencies. Evaluation results on a simulated two-area frequency-load control power grid system are provided to show the effectiveness and performance of the proposed approaches.

Designing anti-windup PI controller for LFC of nonlinear power system combined with DSTS of nuclear power plant and HVDC link

This paper proposes anti-windup proportional integral controller to deal with generation rate constraint problem during a frequency load control. An interconnected two-area power system is used by considering nonlinear constraints for thermal and hydro units combined with dish-Stirling solar thermal system (DSTS) in the first area, the nuclear power plant in the second area, and HVDC link in both areas. The imperialist competitive algorithm was used for optimal adjustment of parameters of the proposed controller. Simulations are performed in different scenarios. The proposed control scheme is compared with conventional PI controller; the effect of the presence of DSTS and HVDC link is investigated, and finally the robustness of the proposed controller against uncertain load is studied. The comparisons are made by using various performance factors of the system response such as overshoot, settling time and rise time. The results show a significant improvement in the system response and reduction in oscillation frequency of the areas and the power of the tie-line.

An optimal dispatching strategy for V2G aggregator participating in supplementary frequency regulation considering EV driving demand and aggregator’s benefits

With the development of Vehicle-to-Grid (V2G) technology and increasing number of electric vehicles (EVs) integrating in power grid, supplementary frequency regulation service provided by V2G aggregator has been seen as the most promising grid ancillary service provided by the integrated EVs. In this paper, an optimal dispatching strategy of V2G aggregator is proposed to satisfy the driving demand of EV owners and maximize the economic benefits of aggregator simultaneously when it participates in supplementary frequency regulation. A judgment module is designed to determine EVs in aggregator whether participating in frequency regulation according to EV battery SOC for EVs’ driving demand, which is calculated by EVs’ daily driving distance. An optimal regulation power calculation model is built to optimize profits of aggregator and tracking performance of frequency load control signal from grid operator. A fair regulation power allocation module is designed to avoid over-discharging of EVs in aggregator. Finally, the proposed strategy is implemented in the simulation experiments to demonstrate its effectiveness.

Kształtowanie obciążeń u odbiorców końcowych w oparciu o częstotliwość napięcia zasilającego

The requirements for frequency to low-voltage distribution networks in the context of the end user loads forming were presented in the paper. Authosr showed the potential of regulation based on voltage frequency. Exemplary calculation for frequency load control based on real load of Polish Energy Power System and frequency data was done. (End user loads forming based on voltage frequency value).

Modeling And Control Of Excitation And Governor Based On Particle Swarm Optimization For Micro Hydro Power Plant

This paper presents the modeling and control of the excitation system via the automatic voltage regulator (AVR) and governor system through the automatic generation control (AGC) or frequency load control (FLC) to improve stability on a micro hydro power plant (MHPP). Three main parts of the generation system are synchronous generator, AVR-excitation, AGC modelled linearly. Generator is modelled by a single machine connected to infinite bus (SMIB) which is equipped by AVR and excitation linear model. Excitation control system made by optimizing the gain of the AVR (K A ) and the governor with the gain of the AGC (K i ). Optimization is done using the method improved particle swarm optimization (IPSO). The main purpose of setting the gain of the AVR-AGC is to stabilize the oscillation frequency of the MHPP which is connected to an infinite bus. Simulations are conducted by inputting step function with 5% load fluctuations as a representation of dynamic load. The simulation results show that the proposed method effectively raises the level of electromechanical damping oscillations the SMIB by generating the comprehensive damping index (CDI) is minimum.

Frequency-load control based on auto-tuning neurons for ship power station

The design of frequency-load controller greatly affects the performance of a ship power station. A common strategy to control frequency and load of the ship power station is to use speed regulator with a PI controller, these schemes require proper and continuous tuning, frequency and load of the diesel-generator are separately controlled, but frequency regulation and load distribution among parallel synchronous generators are interacted. A new parallel PID control technique based on auto-tuning neurons used as a modified hyperbolic tangent function is proposed in this paper, which specialized for frequency-load regulation of the ship power station. Simulation and experimental results show that proposed scheme can achieve an appropriate frequency-load control among parallel synchronous generators, and ensure their stable and economical performances.