FOPID Controller Research Articles

Salp swarm algorithm-based model predictive controller for frequency regulation of solar integrated power system

Global analysis of power system markets project frequency regulation as one of the most profitable ancillary services. It is associated with second-to-second balance of load and frequency within a control area and acquires a principal role in enabling power interchanges while offering better conditions for electricity exchange. In the light of the above, a novel control strategy, namely salp swarm algorithm (SSA)-based model predictive controller, is proposed for frequency regulation of an unequal two-area realistic power system, incorporating solar thermal power plant and conventional thermal plant. Governor dead band, generation rate constraint and transport delay are considered in each control area. Over the past few years, model predictive controller (MPC) has come forward as a prediction-based control strategy for stabilizing dynamical systems while considering non-linearities, system uncertainties and constraints. The MPC parameters are optimized using SSA. The performance of the proposed approach is validated by comparing the dynamic time responses of SSA-optimized MPC with the other SSA-optimized conventional controllers, namely PID, FOPID and cascade PIDN-FOPID controller. The simulation result analysis shows that the proposed optimal MPC outpaces the conventional controllers with respect to peak overshoot, undershoot and settling time of the time responses. A comparative study of various objective functions indicates that, as compared to other indices, integral square error is better for the considered test system. Further, sensitivity analysis reveals the robustiousness of MPC parameters obtained at nominal values and hence is not required to be retuned, against variations in system loading and inertia constant.

Global fast terminal sliding mode controller for hydraulic turbine regulating system with actuator dead zone

This paper investigates the frequency change problem of hydraulic turbine regulating system based on terminal sliding mode control method. By introducing a novel terminal sliding mode surface, a global fast terminal sliding mode controller is designed for the closed loop. This controller eliminates the slow convergence problem which arises in the terminal sliding mode control when the error signal is not near the equilibrium. Meanwhile, following consideration of the error caused by the actuator dead zone, an adaptive RBF estimator based on sliding mode surface is proposed. Through the dead zone error estimation for feed-forward compensation, the composite terminal sliding mode controller has been verified to possess an excellent performance without sacrificing disturbance rejection robustness and stability. Simulations have been carried out to validate the superiority of our proposed methods in comparison with other two other kinds of sliding mode control methods and the commonly used PID and FOPID controller. It is shown that the simulation results are in good agreement with the theoretical analysis.

Comprehensive analysis of interleaved boost converter with simplified H-bridge multilevel inverter based static synchronous compensator system

Power quality is the major concern in the long distance transmission systems, large scale industries and power substations. In this paper, Interleaved Boost Converter (ILBC) interfaced with proposed simplified H-bridge Multilevel Inverter (SHBMLI) is modeled for PV based Static Synchronous Compensator (STATCOM). Proposed SHBMLI has one H bridge and 2 auxiliary bi-directional switches to produce 7 level output and has advantages such as increased current gain and increased efficiency with reduced switching and sources. This paper discusses the comparison of Single Inductor Boost Converter(SIBC), Two Inductor Boost Converter(TIBC) and ILBC based SHBMLI based STATCOM system in terms of output voltage, ripple voltage, THD and receiving end voltage. From the results, it has been proved that, improved receiving end voltage, reduced ripple voltage (0.09V) and THD (1.84%) are obtained by using ILBC interfaced SHBMLI based STATCOM system. Closed loop analysis is conducted for ILBC interfaced SHBMLI based STATCOM system using PI, PID, FOPID and Fuzzy Logic controllers to improve the dynamic response of the system. Studies indicate that Fuzzy Logic controller has a better dynamic response than other controllers with settling time of 0.16s. Stepped Pulse Width Modulation (SPWM) technique is employed for generating switching pulses of the system. The results are illustrated for nonlinear load under unbalanced conditions by considering voltage sag due to the disturbance in the load. The proposed method is modeled and simulated using MATLAB/Simulink software and the results are validated by conducting experiments through prototype model.

Implementation of Intelligent Algorithms for Pitch Angle and Output Power Control of Dfig Wind Turbine System.

The blade pitch angle is the vital part of wind energy system in getting desired output power. PID controller with the modified gains is considered as flexible and is administered for the regulation of blade pitch angle of turbine in this paper because of its lucidity, intermittent in its functionality and with easy usage in control system. FLC has powerful approach for collecting wind turbine response over PI controller where the speed and generator output power acting as input control variables for FLC with which these variables are evenly responsible to maintain proper aerodynamic power and its speed at rated value without any disturbance in output power and at gust speeds, the intelligent algorithms are been implemented to control the pitch angle upon adjusting the angle between the chord line of blades by adopting to new learning techniques as per the data collected. ANFIS had both the features of ANN and Fuzzy Logic Controllers by using Particle Swarm Optimization which gives the better response over the typical PI controller. This paper gives the information of supremacy of FOPID controller with PSO tuning over the other existing controllers. The dominance of the proposed method is made evident with the simulation results using 9MW WTS using MATLAB Simulink.

Optimal tuning of FOPID controller based on PSO algorithm with reference model for a single conical tank system

The fractional order proportional integral derivative controller (FOPID) replaces the conventional PID controller for its immense merits such as its simple structure, better set point tracking, high disturbance rejection, higher capability of handling model uncertainties in nonlinear and real time applications. This paper addresses the effectiveness of the FOPID controller on a level control of single conical system in real time. It is one of the classical nonlinear control problem and its shape not only contributes the proper mixing of liquids and also guarantee to drainage of solid wastes. This study, a dual loop controller is proposed and constructed with a master process and slave process for a level control of a single conical tank system. In the slave process, the output response obtained by the traditional PID controller combined with the conical tank reference model and compared with the output response of the master process. The obtained error signal is used to dynamically correct the parameters of the FOPID controller in the master process. The tuning of FOPID controller is a challenging task due to its presence of extra parameters and it efficiently carried out by particle swarm optimization (PSO) algorithm. The obtained result reveals that the Proposed PSO optimized FOPID controller with reference model demonstrated the better set point tracking, smooth controller response than other conventional integer order controllers.

A Better Stability Control of Inverted Pendulum System Using FMINCON Based FOPID Controller Over Fractional Order Based MRAC Controller

In this article, a stability analysis on an inverted pendulum system has been approached using a fractional order PID controller and a fractional order-based model reference adaptive controller. A modified MIT rule provides an extra degree of freedom, unlike an MIT rule of MRAC controllers to stablize the pendulum angle of the inverted pendulum system which is highly unstable in nature. Here, to analyze better stability performance of the inverted pendulum over the fractional order MIT rule of MRAC controller optimal fractional order, a PID controller has been approached and FMINCON numerical optimization algorithm has been chosen to optimize the fractional order PID controller using ITSE as a scaler objective function. Next, the behaviourial characteristics of the pendulum have been compared between the FMINCON-based FOPID controllers and the fractional order MIT rule of the MRAC controller to show robust performance using an optimal FOPID controller with respect to performance indices increases time, settling time, followed by errors ISE, IAE, ITSE.

Design and simulation of self-tuning fractional order fuzzy PID controller for robotic manipulator

Two-link robotic manipulator system is completely nonlinear and time-varying multi-input-multiple output. In this research, the fractional order fuzzy PID (FOFPID) controller is proposed in order to control the robotic manipulator position. Since real control systems are generally nonlinear systems, therefore, better control of these systems requires the usage of an adaptive or nonlinear controller. So we applied a fuzzy system in order to determine the coefficients of a FOPID controller based on particle swarm optimization (PSO) algorithm. In definition of fitness function for this optimization, we considered integral of absolute error (IAE) and integral of absolute change in controller output (IACCO). Finally, in order to compare this controller with the FPID controller, numerical simulations were performed on the robotic manipulator. The results demonstrate that the overshoot of FOFPID controller is less than the FPID and proposed controller has less oscillations amplitude, totally, its performance is better than the FPID controller.

Fractional-order PID design: Towards transition from state-of-art to state-of-use

This paper presents a new tuning method for fractional-order (FO)PID controllers to simplify current tuning and make FOPID controllers more convenient for industry, i.e. facilitate transition from state-of-art to state-of-use. The number of tuning parameters is reduced from five to three based on popular specification settings for PID controllers without the need for reduced process models which introduce modeling errors. A test batch of 133 simulated processes and two real-life processes are used to test the presented method. A comparative study between the new method and the established CRONE controller, quantifies the performance. The conclusion states that the new method gives fractional controllers with similar performances as the current methods but with a significantly decreased tuning complexity making FOPID controllers more acceptable to industry.

New Design of a Fractional Order Controller Based on Padé Approximation to Enhance a Stable Power System Load Frequency

This paper introduces a design technique of a novel fractional order (FO) proportional-integral-Derivative (PID) controller. The new control technique is a strategy to design a power system stabilizer (PSS) based on Pade approximation (PA). This control strategy is to enhance power system load frequency stability. Load frequency oscillations always follow disturbances that may occur at any point and at any time in power systems, and can affect its performance. This type of PSS controllers is designed specially for the damping of load frequency state variations in power systems. The simple single synchronous machine connected to an infinite bus (SMIB) power system model is taken under study in this paper. Design, analysis and stability tests of the proposed FO-PID controller and its effectiveness are performed for different cases in the proposed power system. MATLAB package is used to carry out the different simulations of power system model with its control strategy. Simulation results in different situations are presented, compared and discussed between two main cases; with system classical control, and with the proposed control strategy. These results present and show the important effects of FO-PID-PSS-PA controllers on the reduction of load frequency oscillations in the proposed power system.

Normalized Robust FOPID Controller Regulation Based on Small Gain Theorem

In this paper, a normalized robust FOPID controller regulation algorithm is proposed. Only one parameter k is necessary to be tuned in the controller regulation process, so the proposed control algorithm is convenient to be applied on both fractional-order systems and integer-order systems. A robustness evaluation function is constructed based on the small gain theorem. Larger robustness evaluation function value will help the system achieve better robustness performance. Another parameter, β, is also available to serve as a tuning knob when larger robust evaluation function value is needed. Therefore, the controlled systems can be stabilized and can achieve quite satisfactory robust control performance using the proposed algorithm. The corresponding robust analysis results are obtained according to different conditions in the discussion. For a special case of widely used fractional-order systems, the FOPI and FOID controllers are presented based on the same tuning scheme together with their robustness discussion. Some examples are shown to verify the robustness of systems controlled by the proposed algorithm.

Design and implementation of digital fractional order PID controller using optimal pole-zero approximation method for magnetic levitation system

The aim of this paper is to employ fractional order proportional integral derivative &#x0028 FO-PID &#x0029 controller and integer order PID controller to control the position of the levitated object in a magnetic levitation system &#x0028 MLS &#x0029, which is inherently nonlinear and unstable system. The proposal is to deploy discrete optimal pole-zero approximation method for realization of digital fractional order controller. An approach of phase shaping by slope cancellation of asymptotic phase plots for zeros and poles within given bandwidth is explored. The controller parameters are tuned using dynamic particle swarm optimization &#x0028 dPSO &#x0029 technique. Effectiveness of the proposed control scheme is verified by simulation and experimental results. The performance of realized digital FO-PID controller has been compared with that of the integer order PID controllers. It is observed that effort required in fractional order control is smaller as compared with its integer counterpart for obtaining the same system performance.

Speed Control of DC Motor Using PID and FOPID Controllers Based on Differential Evolution and PSO

Speed Control of DC Motor Using PID and FOPID Controllers Based on Differential Evolution and PSO

Robust 2-DOF FOPID Controller Design for Maglev System Using Jaya Algorithm

In this paper, 1-Degree of Freedom (1-DOF) and 2-Degree of Freedom (2-DOF) Integer Order (IO) and Fractional Order (FO) Proportional–Integral–Derivative (PID) Controller has been designed for the Magnetic Levitation (Maglev) system. Maglev is one of the most versatile research-oriented laboratory instruments in the field of control systems engineering. The controller for the Maglev system is designed in such a way that a ferromagnetic ball can precisely levitate in a controlled electromagnetic field with particular design specifications. The controller parameters can be appropriately identified by optimizing the objective function with various popular artificial intelligence based evolutionary optimization algorithms. The 2-DOF controller structure takes care of both reference signal tracking and disturbance rejection through the feedback path. The 1 and 2-DOF controller structures with both Integer as well as Fractional Order approaches for different nonlinear systems were already discussed in various papers. However, the application of the Fractional Order control technique on a highly nonlinear Maglev system using the Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Hybrid Particle Swarm Optimization (Hybrid PSO), and recently developed Jaya Algorithm is of our interest. Observation of the final analysis based on different simulation results states that as the controller structure moves from 1-DOF to 2-DOF, the performance of the system and the control signal gets improved. The robustness analysis has also been incorporated in this study which shows that the 1 and 2-DOF IOPID and FOPID controllers designed using different optimization algorithms for the Maglev plant are robust in nature.

Fractional order fuzzy PID optimal control in copper removal process of zinc hydrometallurgy

The copper removal process is the first stage of purification in zinc hydrometallurgy. Due to its dynamic characteristics and complex reaction mechanism, a robust and effective controller to maintain high quality and stability of the outlet-ion-concentration is in great need. In this paper, a fractional order fuzzy proportional integral derivative (FOFPID) controller based on fuzzy logic is proposed to meet this challenge. The proposed work is conducted through a combination of three novel interdependent efforts. First, controller design problem is transformed into a nonconvex optimization problem. Second, a novel method named state transition algorithm (STA) is employed to solve the aforementioned optimization problem. Furthermore, in order to evaluate the performance of the proposed control strategy, the response performance of the system is analyzed. Finally, further tests are carried out to evaluate the performance of FOFPID controller, where disturbances caused by the measurement, flow rate, and inlet-ion-concentration are all taken into account. The simulation results demonstrate the superiority of the FOFPID controller in copper removal process over the competing FOPID and manual control in the same application environment.

A Sepic based AC-DC Convertor using FOPID Controller

A Sepic based AC-DC Convertor using FOPID Controller

Application of Group Hunting Search Optimized Cascade PD-Fractional Order PID Controller in Interconnected Thermal Power System

This paper is an endeavor to enhance the performance of the Automatic Generation Control (AGC) by adopting cascade PD-FOPID (Proportional Derivative - Fractional Order PID) controller in a two-area mutually connected thermal power plant with Generation Rate Constraint (GRC). The performance of the cascade PD-FOPID controller is validated by contrasting PID and FOPID controllers implemented in each area as AGC. The basic goal of the design of these controllers is to lessen the area control error (ACE) of corresponding area by conceding the frequency and tie-line power deviation. Group Hunting Search (GHS) algorithm is adopted to explore the gain parameters of the controllers to lessen the objective function (ITAE). A small step load transition of 0.01 p.u. is enforced in area-1 to investigate the controller performance. Cascade PD-FOPID controller optimized by GHS algorithm performs precisely better than PID and FOPID controller in the proposed system . Citation: Nayak, J. R., and Shaw, B. (2018). Application of Group Hunting Search Optimized Cascade PD-Fractional Order PID Controller in Interconnected Thermal Power System. Trends in Renewable Energy, 4, 22-33. DOI: 10.17737/tre.2018.4.3.0047

Comparison of PID and FOPID controllers tuned by PSO and ABC algorithms for unstable and integrating systems with time delay

SummaryThis paper deals with optimization and design of an integer order–based and fractional order–based proportional integral derivative (PID) controller tuned by particle swarm optimization (PSO) and artificial bee colony (ABC) algorithms. These algorithms were used to find the best parameters for the best controller performance. A comparative study has been made to highlight the advantage of using ABC‐based controller over a PSO‐based controller. The validity of the controller tuning algorithms was tested in 2 different systems with time delay and a nonminimum phase zero used commonly in process control. The optimal tuning process of the PID and fractional order PID controllers has also been performed with 3 different cost functions. From the perspectives of time‐domain performance criteria, such as settling time, rise time, overshoot, and steady‐state error, the controller tuned by ABC gives better dynamic performances than controllers tuned by the PSO. Moreover, the results obtained from robustness analysis showed that the parameters of controller tuned by ABC are quite robust under internal and external disturbances.

Harmonic Comparison of Three Phase Direct Matrix Converter for Reactive Load with Balance and Unbalance Supply Voltage

<span lang="EN-IN">This paper presents harmonic analysis of matrix converter using different control technique for balance and Unbalance three phase input voltage of reactive load. Since Matrix converter is subject to affected either by external disturbance or by load conditions. Due to this the supply voltage becomes unbalance. This cause improper switching of matrix converter results higher harmonics. This harmonics are harmful to the quality of the output power. The switching sequence of the matrix converter is controlled by vector control method. Different control technique is proposed in this paper to get optimized result with reduced harmonic for unbalanced and balance input voltage using PID, Fractional Order PID (PI<sup>λ</sup>Dδ) controller (FOPID), Particle Swarm Optimization (PSO)FOPID. PID control technique result are compared with other optimization technique for best optimum output. The FOPID controller is used to compensates the current and also improvise the quality of energy by reducing the harmonic content. The simulations and hardware results will be presented and interpreted. The effectivess of the proposed system is proven with the results is shown in this paper which produce a better steady state lesser transient rather than the conventional PID method.</span>

Robust and novel two degree of freedom fractional controller based on two-loop topology for inverted pendulum

A rotary single inverted pendulum (RSIP) typically represents a space booster rocket, Segway and similar systems with unstable equilibrium. This paper proposes a novel two degree of freedom (2-DOF) fractional control strategy based on 2-loop topology for RSIP system which can be extended to control the systems with unstable equilibrium. It comprises feedback and feed-forward paths. Primary controller relates the perturbation attenuation while the secondary controller is accountable for set point tracking. To tune the parameters of proposed fractional controller a simple graphical tuning method based on frequency response is used. The study will serve the outstanding experimental results for both, stabilization and trajectory tracking tasks. The study will also serve to present a comparison of the performance of the proposed controller with the 1-DOF FOPID controller and sliding mode controller (SMC) for the RSIP system. Further to confirm the usability of the proposed controller and to avoid the random perturbations sensitivity, robustness, and stability analysis through fractional root-locus and Bode-plot is investigated.

FOPID Controllers and Their Industrial Applications: A Survey of Recent Results

The interest towards using Fractional-order (FO) PID controllers in the industry is mainly fueled by the fact that these controllers have two additional “tuning knobs” that can be used to adjust the control law in a way that would benefit the control loop. However, there are certain points that are rarely addressed in literature, namely: (1) What are the particular advantages (in concrete numbers) of FOPID controllers versus conventional, integer-order (IO) PID controllers in the light of complexities arising in the implementation of the former? (2) For real-time implementation of FOPID controllers, approximations are used that are equivalent to high order linear controllers. What, then, is the benefit of using FOPID controllers? In the present paper, we attempt to address these issues by reviewing recent literature in the field and by providing relevant analysis and recommendations.