Proportional And Integral Controller Research Articles

Tuning proportional integral controller to enhance the photovoltaic system performance

This paper presented a closed loop buck-boost converter controlled by using proportional and integral controller (PIC) for photovoltaic (PV) applications. The mathematical equations of design the solar panel type KC200GT and buck–boost converter is illustrated. The electrical behaviors of solar panel are examined at 1,000 light radiation and room temperature (25 °C) situation. A PIC tuning is difficult with conventional methods such as graphs and mathematical analysis, so for that reason two approaches are used for tuning and optimization of PIC, particle swarm optimization (PSO), and Zeigler–Nichols (ZN). The suggested closed loop application through the converter preserves the constant voltage in the output spite of alterations to the input voltage, decreases settling time, overshoot and ripple voltage to minimum value that enhancement the efficiency of the converter. The results show that the PSO approach is improved than the ZN approach. The proposed model is constructed by using SimPower system tool box in MATLAB package.

Performance Analysis of Microgrid Using Wind Power Based on Steady-State Voltage Stability

This investigation is done for augmentation of steady-state voltage stability in microgrid with doubly fed induction wind generator for the growing need of DG systems in distribution and transmission network. A poor stability in voltage reduces the efficiency of the distributed generation system (DGs). Double Fed Induction Generator (DFIG) is a type of induction generator interconnected into microgrid and it acting an essential role during the performance of microgrid in distributed generation systems of distribution network. The performance characteristics of microgrid with DFIG is analyzed and improved by control strategy. The PI (proportional and integral) control strategy of microgrid with DFIG rooted in double-fed induction generator (DFIG) in pitch angle control in the energy storage system (ESS). The performance analysis microgrid with DFIG is implemented by means of simulink platform in MATLAB software. The outcome was evaluated in this article in favor of steady-state voltage stability enhancement in microgrid with DFIG. This work is done for the achievement of a stable operation microgrid in DG system against disturbances in wind. The proposed work is intended to produce 1.58 MW of reactive power without controller and 0.48 MW, 0.36 MW, and 0.32 MW of power with P, PI, and PID (Proportional–Integral–Derivative) controller with PAC.

Improving gain of real time PI controller using particle swarm optimization in active power filter

This paper incorporates the PSO based PI control for systematic switching function of APF topology. The proportional and integral (PI) gain tuning of active power filter (APF) using the particle swam optimization (PSO) method for reactive power compensation and harmonics mitigation. A conventional PI controller required more computation time and has less accuracy. The harmonic load currents are extracted using an instantaneous real and reactive power scheme. The performance indices including total harmonic distortion, reactive power, power factor and capacitor voltage regulation using PSO trained PI controller is compared with convention PI controller. PSO has quick convergence, minimal adjusting parameters and fast execution to solve non-linear problems. The traditional PI controller is substituted by an online PSO trained PI controller for the objectives of enhancing the dc voltage tracking in APF under non-linear load conditions. The proposed work is developed in sim-power system tool box which is a software package in Matlab/ Simulink.

Sensorless DTC-SVM applied to an induction motor controlled by a three-level inverter using SMSFO

PurposeThe direct torque control (DTC) of induction motor (IM) drive is featured by high ripples in the electromagnetic torque and stator flux profiles because they are controlled by two hysteresis regulators. Furthermore, the machine flux is not directly measurable. Hence, it is better to reconstitute it from the instantaneous electrical equations of the machine. Once the stator flux is estimated, we can guarantee a reliable sensorless DTC control. Thus, the purpose of this research work is to ensure fast response and full reference tracking of the IM under sensorless DTC strategy with desired dynamic behavior and low ripple levels.Design/methodology/approachIn this work, an improved DTC strategy, which is DTC_SVM_3L, is suggested. The first step of the designed approach is to substitute the conventional inverter feeding the motor with a three-level inverter because it guarantees reduced switching losses, improved quality of voltage waveform and low-current total harmonic distortion rate. The second aim of this paper is to make the IM operate at a constant switching frequency by using the nearest three vectors-based space vector modulation (SVM) technique rather than hysteresis controllers. The third objective of this study is to conceive a sliding-mode stator flux observer, which can improve the control performances by using a sensorless algorithm to get an accurate estimation, and consequently, increase the reliability of the system and decrease the cost of using sensors. The stability of the proposed observer is demonstrated based on the Lyapunov theory. To overcome the load change disturbance in the proposed DTC control strategy, this paper exhibits a comparative assessment of four speed regulation methods: classical proportional and integral (PI) regulator, fuzzy logic PI controller, particle swarm optimization PI controller and backstepping regulator. The entire control algorithm was tested under different disturbances such as stator resistance and load torque variations.FindingsIt was ascertained that the IM, controlled with three-level inverter, exhibits good performances under the proposed DTC-SVM strategy based on a sliding-mode observer. The robustness of the suggested approach against parameter variations is also proved.Originality/valueThe theoretical development of the proposed control strategy is thoroughly described. Then, simulations using Matlab/Simulink software are launched to investigate the merits of the sensorless DTC-SVM command of three-level inverter-fed IM drive with different speed regulators.

Design of Time-Mode PI Controller for Switched-Capacitor DC/DC Converter Using Differential Evolution Algorithm—A Design Methodology

This work presents an automated design methodology for time-mode proportional and integral (PI) controllers aimed for an on-chip switched-capacitor (SC) dc/dc converter system. The basis of this design is the use of evolutionary optimization algorithms to find the near-optimal set of sizings for the time-mode PI controller. It is motivated due to the difficulty faced when tuning the controller parameters at a circuit level, which arise as a result of the presence of modeling inaccuracies and the small region for the linearized model where it is defined. Moreover, this design proposes the required modifications for the original design presented for the inductor-based dc/dc converter. These modifications are necessary to operate the SC dc/dc converter in slow switching limit (SSL). The addition of a pulse-width-modulated (PWM)-to-pulse frequency-modulated (PFM) conversion block is presented and elaborated in this article. The controller is codesigned using the differential evolution algorithm for the circuit level implementation to mitigate the issues prior mentioned. The optimized controller is then tested in a simulation environment using TSMC <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.18~\mu \text{m}$ </tex-math></inline-formula> technology. The results of the optimized controller were superior to those of a conventional controller. The optimized system achieved an overall efficiency of 79.1%.

Modelling and Simulation of Perturb and Observe MPPT Algorithm Based on The PI Controller for Photovoltaic System

&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; The most popular type of renewable energy is photovoltaic (PV) because it is a sustainable source and environmentally friendly. The power generated by a PV system varies with changes in ambient conditions such as temperature and sun radiation; therefore, tracking the maximum power generation from a photovoltaic system independent of temperature and radiation factors is very important. In the literature, a number of techniques for achieving the maximum power point have been presented. In this work, the maximum power point tracking (MPPT) system employing perturb and observe (P&amp;O) algorithm is implemented based on the Proportional and Integral (PI) controller on the proposed PV system to achieve the highest power production from photovoltaic (PV) system and enhance the system performance. The proposed PV system is composed of a Photovoltaic array, DC to DC boost type converter and an MPPT algorithm using perturb and observe method. 1Soltech 1STH-220-P module type was chosen in this study for the simulation and proposed PV The array consists of 40 rows of PV modules connected in parallel, while each row consists of 10 modules connected in a series. All elements of the PV system were simulated using MATLAB/Simulink. The proposed model is used to simulate and optimize the photovoltaic array output current, voltage and power features under various environmental conditions including solar temperature and radiation. The simulation results showed that maximum power point tracking approach using perturbation and observation provide high efficiency to get the highest energy from the PV system regardless of variations in environmental conditions. DC to DC boost converter with perfect performance and high voltage gain is also successfully simulated on the developed PV system.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D;

Application of Flower Pollination Algorithm for Solving Complex Large-Scale Power System Restoration Problem Using PDFF Controllers

Automatic Generation Control (AGC) in modern power systems is getting complex, due to intermittency in the output power of multiple sources along with considerable digressions in the loads and system parameters. To address this problem, this paper proposes an approach to calculate Power System Restoration Indices (PSRI) of a 2-area thermal-hydro restructured power system. This study also highlights the necessary ancillary service requirements for the system under a deregulated environment to cater to large-scale power failures and entire system outages. An abrupt change in consumer load demands and disturbances in any control region (area) of a multiarea (interrelated) system causes severe fluctuations in frequency and interarea power exchanges. However, simple Proportional and Integral (PI) controllers are most prevalent in the literature to effectively resolve AGC issues, while its integral gain is smaller due to the larger overshoot in transient performance. Therefore, an attempt has been made with a novel control strategy, known as the pseudoderivative feedforward with feedback (PDFF) controller, is developed to keep the interarea power exchanges and the frequency to the specified limits after load changes. A PDFF controller is designed and implemented using the flower pollination algorithm (FPA) to obtain optimal dynamic performance for different types of potential power flows in a restructured power system under investigation. The proposed PDFF controller localizes the zero at an optimal place that reduces the rise time of the step-response to reduce the excessive overshoot and gives much better dynamic performances as compared to the PI control structure. The Integral Square Error (ISE) is considered as a performance criterion to derive the optimized gain of the PDFF control structure using FPA. Different PSRI are computed based on the transient response of the 2-area deregulated multisource system and different restoration measures to be taken are also discussed. The simulation results clearly show that the proposed approach is very powerful in decreasing the frequency and tie-power digressions under different load perturbations.

Harris Hawks Optimization-Based Algorithm for STATCOM Voltage Regulation of Offshore Wind Farm Grid

Wind energy is among the fastest-growing electric energy resources worldwide. As the electric power generated by wind turbines (WTs) varies, the WT-connected bus voltage fluctuates. This paper presents a study on implementing a swarm-based proportional and integral (PI) controller for GTO-STATCOM voltage regulator to mitigate the voltage fluctuation caused by the output variations of an offshore wind farm. The proposed swarm-based algorithm for the PI controller is Harris Hawks Optimization (HHO). Simulation results obtained by the HHO algorithm are compared with three other swarm-based algorithms and show that STATCOM with HHO-based PI controller can effectively regulate the WT-connected bus voltage under different wind power output conditions. It shows that the STATCOM compensation performance of the proposed algorithm is superior to that of the compared solutions in maintaining the stable WT-connected bus voltage.

Particle swarm optimization tuned unified power flow controller for power oscillation reduction

One of the best flexible AC transmission system (FACTS) is unified power flow controller (UPFC). As it gets more benefit from both real and reactive power transfer, it is used in power system for controlling the transmitted power. The UPFC controls the power on the transmission side of the power system. When the real as well as reactive power is set the UPFC tries to follow the command by using the proportional and integral (PI) controller. But in some power systems the PI controllers cannot produce the proper power due to the power oscillations. These oscillations are created due to PI controller properties. In this paper the PI controller is replaced with the particle swarm optimization tuned PI controller (PSO-PI). It minimizes the power oscillations by using the objective function. The MATLAB 2017b is used to demonstrate the power transfer curves and the voltages. The IEEE 9 bus system is being used as a reference system.

Performance of DVR Using Optimized PI Controller Based Gradient Adaptive Variable Step LMS Control Algorithm

A custom power device known as dynamic voltage restorer (DVR) has been investigated to operate a distribution system at its desired performance. The distribution system with voltage-related power quality issues in the supply side has been addressed through this article using DVR. Four different grid disturbances, such as voltage sag, swell, unbalances, and distortions, have been taken into account while testing the DVR capability. DVR has been controlled using optimized proportional and integral (PI) gains integrated with gradient adaptive variable learning rate least mean square control algorithm. Adaptiveness of variable step-size in LMS makes the control robust in case of dynamics in the system, which assures better performance. Also, the other major contribution of this article is the implementation of optimization-based self-tuning PI gains in the proposed control. The evaluation of optimizer in estimating the PI gains is presented in terms of the response of dc-link voltage DVR. The simulation work of proposed control algorithms on DVR has been done and satisfactory results are found. For the experimental validation, d-SPACE made Micro Lab Box is used as control processor, and both dynamic and steady-state results are discussed for its effectiveness.

Design and Analysis of Grid Tied Renewable Energy System Based E-Chopper Using Main Controller

The primary aim of this research article regulates the power of Embedded Chopper \ (e-chopper) through PI (proportional and integral) controller to maintain constant output from non-reliable variable input. The operation of e-chopper plays an important role to transfer power from primary sources of wind &amp; solar to load and secondary source of the grid to the battery by means of closed-loop operation. When the input is getting from primary source from the e-chopper operates in boost mode and also maintains buck mode when the secondary source charges the battery, which is controlled by Digital Signal Peripheral Interface controller (DSPIC) controller with another PI control structure. Obtains better regulation and operation of whole system for intermittent nature of renewable energy sources of wind and solar, Proper modes of operation requires effective maintenance &amp; efficient utilization of power from both the side to control the system operation in a systematic way. It maintains the constant voltage of the system for reliable operation through an intelligent approach in a systematic way. Hence to obtain this, Main Controller (CLC) is introduced to control the modes of operation in closed-loop structure. Speedgoat real-time objective mechanism plays the role of CLC; it can operate the entire scheme in different modes of operation. Modes are depending on some input parameters like wind velocity (v) in m/s, solar output (Ir), load condition (1/0) &amp; battery state of charge (SOC). Based on these conditions Main controller has to control the modes of operation in an intelligent approach. This system of approach is very much helpful for agriculture irrigation and lighting applications.

Pengembangan Blok Fungsi Kendali PI-Fuzi pada IEC 61499

Automation system in the form of automatic control is needed in one or several operating units in the process industry. Several control system algorithms have been widely implemented in the process industry, one of them is PI (Proportional and Integral) controller. This PI controller has a simple structure, but the adaptive ability of the controller is still not better for the controlled process. Therefore, the development of PI controller is needed to have a better adaptive ability to the process, in order to produce the responses that are also better and more robust. This research develops PI controller by adding the Fuzzy controller algorithm or also known as PI-Fuzzy controller. The PI-Fuzzy controller in this study is applied to the IEC 61499 Programmable Logic Controller (PLC) standard and to see its performance, the PI-Fuzzy controller based on IEC 61499 is tested and validated on an industrial scale process, namely coal mill. The test was carried out for three hours in real-time on the 4DIAC-IDE software, then the response results were compared with the response results of the PI controller. The PI-Fuzzy controller function block based on IEC 61499 made in this study showed good performance in controlling industrial-scale processes. This is demonstrated in testing and validation using a coal mill, with able to achieve the working range of each parameter. The mean value of coal flow parameter is 13.584 kg/s, coal mass accumulation is 2,196 kg, coal output temperature is 83.296 0C, coal moisture is 0.021, and coal fineness is 75.338 %.

Single-bit modulator for wireless power transfer system

&lt;p&gt;This paper proposes a single-bit ADC system based Proportional and Integral (PI) controller to maintain a desired level of power transfer efficiency in Capacitive Power Transfer (CPT) systems. In this paper, a simple single-bit ADC system i.e., Single-Bit Modulator (SBM) is considered as an alternative to the commonly used multi-bit ADC systems. Unique features of employing SBM are 1) its ability to convert analog signals into single-bit signals and 2) its easy integrability in digital chips with linear variable differential transformers (LVDTs) such as FPGAs. A SBM based PI (SBM-PI) controller is designed to judicially interface with the single-bit output of SBM. The proposed (SBM-PI) controller guarantees less hardware resources, latency and regulates the output voltage to provide the desired power transfer efficiency. The behavior of SBM-PI controller is compared to that of a conventional multi-bit controller, with the results of both controllers being identical. The effectiveness of the proposed controller with SBM is further demonstrated using the experimental prototype of CPT by implementing a SBM-PI controller using $16$ MHz ATmega8 microcontroller. The experimental results from a laboratory prototype illustrate that SBM-PI controller successfully regulates the output voltage of CPT to control the power flow.&lt;/p&gt;

An Adaptive PI Controller Design for DC-Link Voltage Control of Single-Phase Grid-Connected Converters

Conventionally, standard proportional and integral (PI) controllers with constant PI gains are commonly used for the dc-link voltage control of single-phase grid-connected converters (GCCs). For such controllers, the selection of the PI gains will lead to a tradeoff between two control objectives: 1) the reduction of the dc-link voltage fluctuations caused by random swings of the active power drawn by the single-phase GCC; and 2) the reduction of the grid current harmonics mainly caused by the 2f oscillation of the active power in single-phase applications. To solve this tradeoff, this paper presents a systematic approach for the design of an adaptive PI controller for the dc-link voltage control of single-phase GCCs. The proposed design approach is simple and it provides a convenient method to properly determine the adaptive PI controller parameters. Representative simulation and experimental results are presented and discussed in order to show the effectiveness of the proposed dc-link voltage controller.

Voltage-Sensor-Based MPPT for Stand-Alone PV Systems Through Voltage Reference Control

A single voltage-sensor-based maximum power point tracking (MPPT) controller with improved tracking performance is presented in this paper. The MPPT controller can be implemented by either direct duty cycle or voltage reference control in conjunction with a proportional and integral (PI) controller. The voltage reference control has the advantages of faster convergence and small oscillations in steady state compared with the direct duty cycle method. Moreover, the controller gains can be analytically calculated unlike trial-and-error-based selection of scaling factors for the direct duty cycle method. Thus, voltage-sensor-based MPPT algorithm through a voltage reference control technique with the help of the PI controller is developed for minimizing the tracking time and steady-state oscillations. Selection of the objective function to mitigate the drawbacks associated with the voltage-sensor-based algorithm for a decrease in solar irradiance is also demonstrated. The tracking performance of the proposed algorithm is tested through simulation and experimentation of the designed prototype.

Precise measurement and control of the pressure-driven flows for microfluidic systems.

The pressure-driven device is designed and the flow rates of the microfluidic systems can be supplied by the pressure-driven flows, which can significantly reduce the flow-rate fluctuations coming from the pump source. For pressure-driven flows, the flow rates of the fluids can be predicted by measuring the pressure drop along a polytetrafluoroethylene (PTFE) tubing. Especially, by varying the geometrical parameters of the PTFE tubing, the predicted flow rates of the fluids are compared with the experimental measurements, and the testing precision of the pressure-driven flows can be obtained. Meanwhile, the dynamic characteristics of the open-loop and closed-loop control pressure-driven device are comparatively studied. Particularly, a proportional and integral (PI) controller is integrated with the closed-loop control pressure-driven device, and the effects of the parameters of the PI controller on the dynamic characteristics of the pressure-driven devices are mainly discussed. Most importantly, by improving the dynamic characteristics of the pressure-driven devices, precise measurement and control of the pressure-driven flows can be achieved for microfluidic systems.

Real-Time Simulator based hybrid control of DFIG-WES

This paper presents the analysis and design of recurrent neural network (RNN) and proportional and integral(PI) controller based hybrid control(HC) of doubly fed induction generator (DFIG). The proposed HC shows the quick dynamic and good transient response during the sudden changes in wind speed as well as generator speed. Further performance of proposed hybrid controller has been analyzed independently with RNN and PI control as its components. The HC along with RNN gives effective performance compared to conventional DTC (CDTC) and PI DTC in terms of flux ripples,torque ripples and settling time. The proposed technique is implemented in real-time simulator (RTS) based OPAL-RT and MATLAB/SIMULINK environment at a rating of 5.5 KW system under steeply and randomly change in wind velocity.

Hybrid PI controller constructed with paraconsistent annotated logic

In this work a new type of hybrid PI controller is presented using the Paraconsistent Logic (PL) as the basis for the mathematical and logical treatment of the signals corresponding to the control variables. This control has the conventional actions PI (Proportional and Integral) together with the logical actions structured in the concepts of Paraconsistent Logic. Compared to conventional techniques, this new type of Hybrid PI Controller with Paraconsistent Logic responded well to the various tests performed in the control loop. The tests and the technical validations were done with evidences that prove the efficiency of the paraconsistent concepts.

Performance analysis of dynamic voltage restorer using improved PSO technique

ABSTRACTThis paper has discussed the study of the performance of dynamic voltage restorer (DVR) taking different voltage sag conditions in the supply voltage of the distribution system for linear and non-linear load. DVR is employed to mitigate the voltage sag. Proportional and integral (PI) controller is used for the control of DVR to mitigate the voltage sag. Synchronous reference frame theorybased control algorithm has been implemented for generating reference voltages. In this paper, an efficient improved particle swarm optimisation technique for optimizing the gain parameters of the PI controller has been proposed. The performance and suitability of DVR is validated through MATLAB simulation results and use of Sim Power Systems Blocksets. Integral squared error is implemented to check the performance and suitability of DVR. Extensive results of the proposed method are presented and compared with conventional Ziegler Nichols and genetic algorithm methods of tuning gain parameters of PI controllers.

Study on reducing the charge delay of the no-insulation HTS coil after solder impregnation

A new kind of Impregnation method using conductive material, solder, was proposed recently. Experimental results showed that the solder impregnation (SIM) method was a feasible method for fixing no-insulation (NI) coils. However, the charge delay of the solder impregnated coil is too long which is one of the shortcomings of this method. Therefore, this paper focuses on using the proportional and integral (PI) feedback control of the power supply to reduce the charge time of the SIM coil. Comparing the charge delay of the SIM coil without and with the PI control, the time to reach the target magnetic could be reduced from about 350 s to about 20 s and the relative overshoot could be limited within 4%. The test results show that the charge delay of the SIM coil can be well addressed. Moreover, for comparison, an insulation coil and a NI coil were both fabricated and tested.