AGC System Research Articles

Application of RT-Lab in Multi-Area AGC System under Deregulated Environment Considering IPFC-SMES

Application of RT-Lab in Multi-Area AGC System under Deregulated Environment Considering IPFC-SMES

Research on Pump-Controlled AGC Micro-Displacement Position Control of Lithium Battery Pole Strip Mill Based on Friction Compensation Control Strategy of Imoroved LuGre Pattern

Accurate mathematical patterning of friction has always been a significant research project in the domains of machinery and control, and has played a crucial role in the analysis, control and compensation of mechanical systems containing friction. For high-property electrohydraulic servo control systems, friction compensation is an urgent problem to be solved. The LuGre friction pattern can represent most frictional behaviors, but the LuGre friction pattern is piecewise-continuous, making it non-differentiable. Therefore, the question of how to combine the LuGre friction pattern, enhancing its tracking capacity and robust performance problem, to friction perturbation in hydraulic backstep devices is an important focus for research. In this study, the conventional LuGre friction pattern was enhanced using the continuous differentiability of a friction of rest pattern that laid the foundation of a smooth tangent function. Laying the foundation of an electrohydraulic servo pump-controlled hydraulic roll-gap thickness automatic control system (pump-controlled AGC) pattern, a self-adapting friction compensation controller laid the foundation of the enhanced LuGre pattern. The gradual tracking capacity was determined academically using conditions of parameter, uncertainty and nonlinear friction, and the position control precision of the pump-controlled AGC system was enhanced. The steady-state error of the self-adapting friction compensation control system, which laid the foundation of the enhanced LuGre pattern, attained ±0.1 μm, and the tracking capacity was better than the LuGre pattern control and the conventional PID control strategy at low input speed.

Research on AGC Nonlinear Compensation Control for Electro-Hydraulic Servo Pump Control of a Lithium Battery Pole Strip Mill

Electrode roll forming involves rolling a battery electrode into a preset thickness using a hydraulic roll gap thickness automatic control system (hydraulic AGC for short). The pump-controlled AGC is a highly nonlinear servo system, which is a combination of mechanical, hydraulic and electronic control disciplines; thus, as a new technology, it still faces many challenges in the field of pole plate rolling. In this paper, electro-hydraulic servo pump-controlled AGC technology is replaced by electro-hydraulic servo valve-controlled AGC technology. With pump-controlled AGC high-precision thickness control as the research objective, the fuzzy control method is selected to deal with complex nonlinear systems based on pump-controlled AGC nonlinear stiffness characteristics and nonlinear transmission characteristics. A characteristic compensation control strategy is proposed. At the same time, considering the load fluctuation caused by the uneven thickness of the electrode plate under the intermittent coating rolling condition of a lithium battery, the fuzzy internal model (IMC) compensation control strategy was proposed to compensate the structural characteristics of the electrode plate rolling. Comparative experiments show that the position control accuracy of the pump-controlled AGC system can be improved significantly by using a fuzzy IMC compensation control strategy. The steady-state accuracy of the slope signal can reach ±0.7 μm, and the position-following accuracy of the sinusoidal signal can reach ±1.8 μm. In addition, this study will assist technological upgrades to lithium battery electrode roll forming and fixed-roll-gap rolling, laying a theoretical foundation for the promotion of pump control technology in the field of electrode rolling.

Enhancing decentralized frequency regulation approach in mixed source of generation diversified with wind and PV integration deploying artificial gorilla troops algorithm

Nowadays, the penetration of renewable energy sources, mainly wind and solar photovoltaic systems, into the existing power systems, destabilizes the grid, especially in the aspect of frequency regulation. AGC is one of the most important tasks in this mixed-generation environment to maintain the balance between the generated and consumed electricity, thus keeping the system frequency at an acceptable level. Therefore, AGC needs to be optimized for the noisy and volatile output of RESs. AGTA is a recent optimization method developed based on the social foraging behavior of gorillas, being a sophisticated way of exploration and exploitation. Therefore, the method is implemented in AGC. By mimicking the social behaviour and foraging strategy, the group gives rise to a new technique for enhancing the efficiency and response of the AGC system in light of wind and PV energy generation variation. A two-area power system model has been formulated characterized by the existence of wind and PV generation in addition to the conventional sources of the power system. This model is meant to simulate diverse situations to give an idea as regards the capability of the new algorithm to enhance grid stability and adaptability. The simulated results show that the proposed AGTA significantly surpasses other conventional optimization methods for AGC and results in an effective frequency control strategy. it confirms the potential of the AGTA from a new perspective in providing a feasible option for decentralized frequency regulation in a multi-generation landscape.

Pump-Controlled AGC Micro-Displacement Position Control of Lithium Battery Pole Strip Mill Based on Friction Model

Electrode roll-forming refers to rolling a battery electrode into a preset thickness through the electro-hydraulic servo pump-controlled hydraulic roll gap thickness automatic control system (known to as pump-controlled AGC). Compared with the motor servo system, the friction problem of the electro-hydraulic servo system is more serious and the friction problem of the actuator itself is very prominent. Moreover, low-speed performance is one of its core indicators, the friction phenomenon is the most abundant during the low-speed stage and the impact on the servo system is also the most obvious. Therefore, for high-performance electro-hydraulic servo control, friction compensation is not only unavoidable, but also a very difficult problem. Aiming to influence the friction on the position control of the pump-controlled system of a lithium battery pole strip mill, the rolling mechanism and process procedure under micro-displacement position control based on the friction model were studied and compared from the perspective of considering friction factors, and a friction compensation controller based on the LuGre model was designed. The control precision of a pump-controlled AGC system was improved through combination with an adaptive robust controller. Because of the diversity of unmeasurable states of the system, a dual observer was designed, and the known model of the system was added to the observer. In the final comparative experiment, the steady-state accuracy of the friction adaptive robust compensation controller system based on the LuGre model reached ±0.3 μm, which is superior to the fuzzy IMC compensation and traditional PID control strategies.

Detection of False Data Injection Attack in AGC System Based on Random Forest

False data injection attacks change the control effect of automatic generation control systems, which may cause a destructive impact on power systems. In this paper, the data from the regular operation of a system and the data from false data injection attacks in the historical data are studied and classified. The normal operating parameters and abnormal operation parameters under various attack scenarios are collected as samples for training the detection model based on time series. The random forest algorithm model is selected for detection through the comparison of detection effects, and various data training models are accumulated during the operation process to improve the model’s accuracy. Finally, Simulink simulation experiments verify the consistency of the detection results of the simulated attack algorithm. This detection method can realize real-time attack detection and synchronize the detection results to the database with high timeliness. It can be used in systems with rich data samples and has broad applicability.

Phase locked loop parameterisation in AC/DC interconnected system for a multi-source AGC system under open market environment

This article emphasises on deregulated AGC of a realistic multi-machine gas - thermal plant with dish-Stirling solar-thermal (DSTS) as additional power generation sources in each control area by taking into accounts of AC/DC with phase locked loop (PLL) dynamics. Eigenvalue analysis confirms the steadiness of the reasonable power system with various interconnections such as AC, AC/DC link and AC/DC with PLL dynamics. A series form of proportional-integral-derivative (PID) namely proportional gain cascaded with integral and double-derivative (PI+DD+) controller is employed as secondary controller in each control areas for robust AGC to carry out market transactions under deregulated environment. Exploring the system with different type of interconnections infer that proper tuning of PLL function parameters may synchronise the grid better than without employing PLL. The performance of PI+DD+ controller along with optimum PLL gains commensurate with wide variations in governor, turbine, fuel and compressor discharge time constant of gas turbine plant.

Phase locked loop parameterisation in AC/DC interconnected system for a multi-source AGC system under open market environment

Phase locked loop parameterisation in AC/DC interconnected system for a multi-source AGC system under open market environment

Fuzzy Logic Controller Equilibrium Base to Enhance AGC System Performance with Renewable Energy Disturbances

Owing to the various sources of complexity in the electrical power system, such as integrating intermittent renewable energy resources and widely spread nonlinear power system components, which result in sudden changes in the power system operating conditions, the conventional PID controller fails to track such dynamic challenges to mitigate the frequency deviation problem. Thus, in this paper, a fuzzy PI controller is proposed to enhance the automatic generation control system (AGC) against step disturbance, dynamic disturbance, and wind energy disturbance in a single area system. The proposed controller is initialized by using Equilibrium Optimization and proved its superiority through comparison with a classical PI optimized base. Results show that the fuzzy PI controller can reduce the peak-to-peak deviation in the frequency by 30–59% under wind disturbance, compared to a classical PI optimized base. Moreover, a fuzzy PID controller is also proposed and EO initialized in this paper to compare with the PIDA optimized by several techniques in the two-area system. Results show that the fuzzy PID controller can reduce the peak-to-peak deviation in the frequency of area 1 by 30–50% and the deviation of frequency in area 2 by 13–48% under wave disturbance, compared to the classical PIDA optimized base.

Research on wind farm participating in AGC based on wind power variogram characteristics.

The increasing integration of large-scale wind power aggravates the difficulty of maintaining system frequency deviations in a certain range. The frequency regulation pressure of conventional generators increases, which requires wind farms to participate in system frequency regulation. In this paper, a multi-area interconnected power system frequency response model with wind power is established. Based on the frequency response model, the state space model of regional interconnected power system is presented. Then, the wind power variogram characteristics are introduced for estimating wind power variations in different time-scales. By predicting the wind power variations in AGC time-scale, a strategy of wind farm participating in AGC system is proposed and performed based on model predictive control (MPC). The control strategy makes the conventional units and wind farms to participate in AGC system coordinately. Simulation results are provided which verifies the feasibility and validity of the proposed strategy.

Automatic Generation Control Using an Improved Artificial Electric Field in Multi-Area Power System

This paper proposes a novel Improved Artificial Electric Field Algorithm (IAEF)-based AGC in a multi-area power system to minimize the area control error and to obtain an optimal solution. Here, four area AGC systems equipped with the PID controller are examined for the study processes. Also, an optimal gain value for the PID controller is obtained by employing an IAEFA; thus minimizing the area control error (ACE). In addition to this, nine different test functions are employed to evaluate the performances of the proposed IAEF-based AGC of a multi-area power system and are compared with several optimization approaches such as AEF algorithm, BBO Algorithm, PSO Algorithm as well as DE Algorithm. Also, the performance evaluation based on three different simulation strategies such as simulation based on time domain, Random disturbances of the AGC system as well as System Dynamics for maximum frequency deviation and Percentage Improvement for a four area power system. Here, the maximum frequency deviations for four areas are −0.0132, −0.0145, −0.0122 and −0.0120, respectively. Moreover, the percentage improvements with respect to the IAEF with respect to the PID controllers are 67.32%, 57.21%, 47.26% and 55.47%, respectively. The experimental analysis reveals that the proposed approach provides very less tie-line control error and better optimal tuning of the PID controller when compared with all other approaches.

Development of MADB of P‐I controller using LMI technique in a renewable energy based AGC system and study its application in a deregulated environment including energy storage device

AbstractIn recent decades, inclusion of renewable resources is considered as one of the most promising options for the long run uninterrupted power supply without depending on conventional resources. Thus, the renewable energy generation will get more attention and massive growing, so that the goal of 40% share of electricity in the worldwide energy portfolio in 2050 would be realized. But during replacement of renewable energy by conventional energy, engineers are facing a lot of problem due to solar generation, wind generation change their characteristic rapidly with weather condition, which may cause large synchronizing imbalance between different units and generate large system delay or communication delay in large interconnected grid. In this article, the authors propose linear matrix inequalities techniques to developed margin of allowable delay for delay dependent stable hybrid system. Initially, to judge the efficacy of proposed chaotic atomic search optimization (CASO) algorithm over other evolutionary algorithms with PID controller, a thermal‐hydro gas system is considered. The second part of this article is motivated by the fact that proposed CASO algorithm with P‐I controller is superior in contrast to bacterial foraging algorithm technique. In addition to this, some energy storage devices such as fuel cell, aqua electrolyzer, and ultra‐capacitor are used to achieve a better dynamic response within specified delay margin. Moreover, to study the impact of communication delays (delay margin) due to the loss of synchronism between solar‐wind (for their unpredicted environmental features) and thermal unit (nonlinearities like generation rate constraints, boiler dynamics, and governor with the dead band) are considered in thermal unit and the simulation results verify with the effectiveness of the proposed approach on providing a balance between the delay margin and the damping performances is evaluated under deregulated environment. The simulation results help to make an inter‐relation between the delay margin and the controller gain (P‐I) which help the system operator in designing controllers gain for stable operation of the proposed hybrid system.

Automatic Control System of Hydraulic Tension Pilot Warm Rolling Mill

In order to meet the warm rolling demand and deal with the inefficiency of cold-rolled deformation metals such as high-strength steel, silicon steel and magnesium-nickel alloy, etc., The state key Laboratory of Rolling technology and Automation of Northeastern University(NEU-RAL) designed and manufactured a new pilot warm rolling mill that can achieve heating on line in the rolling process. This paper introduces equipment constitutes, and its main functions and features. The paper also describes its temperature control system, AGC system and ATC system during the warm rolling process in details. Multiple experiments have proven that the pilot warm rolling mill can not only simulate the actual production process to produce the hard-deformed metals, provide innovative technology, but also offer easy to use experimental equipment for steel industry researchers.

Instability Condition Derivation for Hydraulic AGC System under Pressure Closed‐Loop Control

In strip rolling, hydraulic automatic gauge control (HAGC) system is the key element to guarantee the precision of strip gauge. The stability of the kernel pressure closed loop (PCL) in the HAGC system plays an essential role in guaranteeing the rolling process with high performance. Nevertheless, there is some difficulty in exploring the instability mechanism of the HAGC system due to the fact that the PCL is a representative nonlinear closed‐loop control system. In this work, for each component of the HAGC system, the mathematical model was established. And on the basis of the linking relation of various elements, we derived the incremental transfer model of the PCL system. Furthermore, in accordance with the deduced information transfer relation, the transfer block diagram of disturbing variable of the PCL system was obtained. Moreover, for the purpose of deriving the instability condition of the PCL system, the Popov frequency criterion was employed. The instability conditions of the HAGC system were obtained under PCL control. Furthermore, the derived instability conditions of the HAGC system were experimentally verified under various working conditions. The research results provide a fundamental foundation for studying the instability mechanism of the HAGC system.

Digital AGC Circuit Design based on FPGA

Users' demand for broadband wireless and mobile is increasing, making wireless broadband access technology WiMAX, arise at the historic moment, rapid development, has become the focus of attention in the industry these two years. In this paper, based on the WiMAX transmission standard 802.16D, the AGC of channel demodulation in WiMAX receiver is described in detail. Firstly, the basic components and main characteristic indexes of the AUTOMATIC gain control system are introduced, and the output formula of AGC model is obtained through the analysis of a step-type AGC. Then the adc and AGC circuits in THE AGC system in the WiMAX receiver are introduced and analyzed theoretically. In this paper, SPW model is used to analyze the algorithm of the basic structure of AGC circuit. Combined with the simulation results, AGC circuit is explained in detail and parameters are explained. Finally, the verification results based on SPW and FPGA are given. The individual performance test of AGC is carried out through SPW, and combined with the performance test of the simulation system, it shows that AGC can work in cooperation with other modules of the system. In FPGA test, it can be proved that AGC can also work well with Verilog.

Fuzzy control strategy of interconnected power grid AGC system based on particle swarm optimization

Frequency is one of the key indicators of power quality. The power load is constantly changing and has uncontrollability. The change of load will affect the frequency of the system. The power system always hopes to keep the frequency as constant as possible, which leads to the problem of frequency control. The mechanism modeling of the multi-region interconnected power grid system is carried out, and the frequency response of the networked system is analyzed by building a simulation platform. Aiming at the shortcomings of “AGC controller” using fuzzy PID control, according to the particle swarm optimization algorithm, a fuzzy adaptive PID controller based on particle swarm algorithm is designed. The simulation results show that the fuzzy adaptive PID controller based on particle swarm algorithm can better improve the dynamic performance of the system.

CMOS Analog AGC for Biomedical Applications

In this paper, we present the design of an analog Automatic Gain Control with a small silicon area and reduced power consumption using a 0.5 μ m process. The design uses a classical approach implementing the AGC system with simple blocks, such as: peak detector, difference amplifier, four-quadrant multiplier, and inversor amplifier. Those blocks were realized by using a modified Miller type OPAMP, which allows indirect compensation, while the peak detector uses a MOS diode. The AGC design is simulated using the Tanner-Eda environment and Berkeley models BSIM49 of the On-Semiconductor C5 process, and it was fabricated through the MOSIS prototyping service. The AGC system has an operation frequency of around 1 kHz, covering the range of biomedical applications, power consumption of 200 μ W, and the design occupies a silicon area of approximately 508.8 μ m × 317.7 μ m. According to the characteristics obtained at the experimental level (attack and release time), this AGC can be applied to hearing aid systems.

DIGITAL AUTOMATIC GAIN CONTROL SYSTEM MODELING

The goal of automatic gain control is to maintain a constant output power level. Automatic gain control systems are used in various communication systems, both analog and digital. However, for all the variety of digital automatic gain control algorithms, the adjustment of the control parameters during the simulation process in reality is often ignored. In practice, this can lead to long-term overloads with a large change of the input signal power. There is also the risk that the model used was designed to work in linear mode only. In nonlinear mode, its behavior may not always be predictable. Research subject. The purpose of this article is to analyze digital AGC system characteristics and to model its operation in Matlab. Method. As part of the study, a Matlab model of hybrid automatic gain control system was developed. Core results. It is shown that the control time of the digital automatic gain control system with a non-linear gain control characteristic does not depend on the amplitude of the input signal. The performance of the proposed digital model is limited by the dynamic range of the linear path and the analog-to-digital converter. The mathematical dependence of the response time of the model on the input signal level change is obtained, in which the time constant of the automatic gain control filter has been replaced by the time constant of the entire automatic gain control system. Practical relevance. A digital model of hybrid automatic gain control system is proposed, which will allow to simulate digital automatic gain control systems parameters for both small and large changes in the input signal level. The results of this work are relevant to the development of digital receivers for communication systems of various purposes.

Simulation Research of Frequency Modulation Control Based on PID

When the balance of power system is broken, the frequency of power system will be deviated. Induction motors are mostly used in industry. Frequency is closely related to the change of speed and output power. Firstly, this paper focuses on the analysis of the mathematical model of the inter-regional tie-line and deduces the Laplace transform of the power variation of the tie-line. The physical model is established to analyse. The fluctuation of the two regions and the interconnected power grid is obtained. The operating point will change in the case of disturbance. The relationship between the switching power deviation of tie-line and the disturbance position point. Through the simulation of the classical two-zone model, the simulation effect of the PID controller is better than that of the conventional controller. The control effect is remarkable, which provides a certain basis for later research. The ideal adjustment parameters of the PID controller are obtained by trial-and-error method. The dynamic and robust performances of the AGC system are further verified by simulation.

Hybrid Taguchi Genetic Algorithm-Based AGC Controller for Multisource Interconnected Power System

—This article presents hybrid Taguchi-genetic algorithm (HTGA) tuned automatic generation controller for two areas interconnected multisource power system model. The control areas consist of thermal, hydro, and doubly fed induction generator-based wind power plants. The optimal tuning of AGC controller using genetic algorithm is less robust due to larger standard deviation of the fitness values. Therefore, Taguchi method which is based on modified statistical approach and has systematic reasoning ability is used to enhance the performance of genetic algorithm. The simulation study is carried out with the optimum gains of AGC controller obtained from HTGA, conventional GA and conventional techniques. The dynamic stability of the power system model is examined to analyze the performance of the HTGA technique. From investigations it is quite clear that the optimum gains of AGC system obtained from HTGA technique has better response in the dynamic stability of the interconnected multisource power system as compared to genetic algorithm and conventional technique.