جستجوی مقالات مرتبط با کلیدواژه « PID Controller » در نشریات گروه « فنی و مهندسی »

The Load Frequency Control (LFC) has been a major subject in electric power system and is be-coming more significant system in recent decades. This paper targets to investigate the problem of LFC in interconnected power systems in order to obtain robust state. In this paper, a design method for a robust controller, based on PID, has been presented to overcome the robustness against uncertainties. To achieve optimal PID, Particle Swarm Optimization (PSO) has been em-ployed to obtain coefficients of the SMC. Variations of uncertain parameters are considered be-tween -40% and +40% of nominal values. The simulation results show that the system response with the proposed PID is better than the conventional PID controller. It is also shown that the transient response of the tie line power can be improved.

This research proposes an innovative process to locate devices in elevation using structural results in uncontrolled and controlled (passive and active) states, considering Soil-Structure Interaction (SSI) effects, especially for soft soil. Also, a Proportional Integral Derivative (PID) controller with active single and multiple control devices is used for tall buildings under earthquakes. In addition, the simultaneous and non-simultaneous tuning of the design parameters are examined. The results of applying PID with a Multiple Active Tuned Mass Damper (MATMD) compared with the Single-Active Tuned Mass Damper (SATMD) show that the proposed process of locating the control devices reduces responses significantly. It also reduces the computational efforts of the optimization noticeably. The results of the non-simultaneous tuning of design parameters in all states also indicate an increase in the instability potential of the structure compared with simultaneous tuning. On the other hand, the reduction of the Root Mean Square (RMS) of the responses compared with the uncontrolled state confirms the effective performance of the system during earthquakes. Therefore, this research helps researchers gain a new design vision of how to locate control devices in tall buildings without optimization calculations and how to set parameters in the presence of SSI effects.

Load frequency control is an important factor of supplying quality electricity in an interconnected power system. As a result, an optimally tuned Proportional-Integral-Derivative (PID) controller is proposed in this work to eliminate frequency errors caused by unexpected load changes while maintaining tie-line power exchange. The PID controller is tuned using several optimization techniques such as GA, PSO, SCA, and GWO. A two-area power system with Generation Rate Constraint is studied in the first instance, and a three-area thermal power system with both generation rate constraint and dead band effect is considered in the second case. In both scenarios, a PID controller is employed for each area. When compared to the results of other optimization approaches for the same integrated power system, such as Genetic Algorithm, Particle Swarm Optimization, and Sine Cosine Algorithm, the GWO-based PID controller outperforms them in both scenarios. According to the simulation findings, the GWO technique gives better dynamic responses in terms of overshoot value, settling time, and Integral Time Absolute Error. Finally, to evaluate the robustness of the suggested optimization strategies, sensitivity analysis is done by modifying the system parameters (turbine time constant, governor time constant, and both simultaneously) in the range of 25% from their nominal values.

In this paper, the control of a three-axis rigid satellite attitude control system with a fractional order proportional-integral-derivative (PID) controller is investigated in the presence of disturbance and parametric uncertainties. The reaction wheel actuator with the first-order dynamic model is used to control the attitude of the satellite. Uncertainties are considered on satellite moment inertia, actuator model and amplitude and frequency of external disturbances. External disturbances are modeled with two fixed and periodic parts and uncertainty is also considered on the disturbances model. The integer order controller is also used for the same conditions to compare the results with the fractional order controller. The usual Granwald-Letinkov definition is used to solve integrals and fractional order derivatives. The mean absolute of the pointing error of the satellite pointing maneuver has been selected as an objective function of the optimization problem. The controller gains in integer and fractional order are obtained by particle swarm evolution algorithm (PSO) optimization method. The performance criterion has been studied in terms of the controller time response and also in terms of the standard deviation of the mentioned uncertainties and external disturbance. The results show that the fractional order controller performs more accurate and robustness than the integer order controllers in the face of uncertainty and disturbance.

In this article, it deals with the modeling of the absorption process of acid gases in the contact tower by the amine fluid in the Khangiran Gas Refinery. The performed simulations show that the concentration of acid gases in the amine fluid increases with the reduction of the contact surface in the contact tower. The obtained model is in good agreement with operational data. In this research, the identification of sources of noise and fluctuations in the mentioned unit, adding the modeling of sensors and actuators and control systems to the simulation, especially PID control, has also been investigated.
By simulating and implementing PID control on the sour gas feed valve of the contact tower and making step changes in the input setting point, fluctuations were observed in all the variables of the absorption tower.
These fluctuations, along with other sensor uncertainties such as temperature sensors, flow transmitters, and pressure transmitters, indicate the presence of fluctuations throughout the tower. In order to eliminate these fluctuations, a controller based on fuzzy logic was used. The appropriate reduction in fluctuations and disturbances by this controller up to 80% shows the success of this controller in eliminating the chattering phenomenon in the gas purification unit.

Automated Guided Vehicles (AGVs) have been widely used in industrial factories and seaport due to their high efficiency and ability to move in recent years. Nevertheless, controlling AGVs to keep moving in the predefined (correct) direction is one of their most important challenges. In this paper, an automated guided control system is designed using the direct current of servomotor. In order to guide the automatic control robot in the predefined and rotational paths, the Proportional-Integral-Derivative (PID) control system with proportional, integral, and derivative parts is used. Adaptive adjustment of PID controller coefficients is difficult due to the nature of the used control system location. Hence in this study, an optimally set up of the coefficients of PID controller is used in control system of AGV by applying adaptive Radial Basis Function Neural Network (RBFNN). The simulation results indicate that the proposed controlling scheme can optimally increase the accuracy rather than traditional PID-based method. In addition, the proposed scheme is practically implemented as a prototype robot leading to provide an experimental validation to be used as an applicable solution in AGV control systems due to the low cost of design and optimal performance.

Exchanger system is widely used in oil, gas and petrochemical plants because it can sustain wide range of temperature and pressure. The main purpose of a exchanger system is to transfer from a hot fluid to a cooler fluid or conversely, so temperature control of outlet fluid is of prime importance. To control the temperature of outlet fluid of the exchanger system a conventional PID controller can be used. Due to inherent disadvantages of conventional control techniques, Fuzzy logic controller is employed to control the temperature of outlet fluid of the exchanger system. The designed controller regulates the temperature of the outgoing fluid to a desired set point in the shortest possible time irrespective of load and process disturbances, equipment saturation and nonlinearity.