Eigenvalue, Robustness and Time Delay Analysis of Hierarchical Control Scheme in Multi-DER Microgrid to Enhance Small/Large-Signal Stability Using Complementary Loop and Fuzzy Logic Controller

2017 ◽  
Vol 26 (06) ◽  
pp. 1750099 ◽  
Author(s):  
Hamid Reza Baghaee ◽  
Mojtaba Mirsalim ◽  
Gevork B. Gharehpetian ◽  
Heidar Ali Talebi
Keyword(s):  
Fuzzy Logic ◽  
Time Delay ◽  
Fuzzy Logic Controller ◽  
Reactive Power ◽  
Hierarchical Control ◽  
System Stability ◽  
Delay Analysis ◽  
Large Signal ◽  
Control Scheme ◽  
Real Time Digital Simulator

In this paper, the proposed hierarchical control scheme adds new control loop to control the reactive power reference by a fuzzy logic controller to have the benefit of increasing the system stability margins and moreover, eigenvalue, robustness and time delay analysis of proposed control scheme are presented. The reported droop-based control methods of VSI-based microgrids including hierarchical droop-based control scheme are limited to primary and secondary control levels while the proposed control scheme is completely analyzed so that the three hierarchical control levels modeled for both grid-connected mode and islanded mode. This scheme maintains the stability of microgrids not only for the small-signal events, but also for large-signal disturbances such as three phase and single phase to ground faults, heavy motor starting, etc. However, power sharing to loads and network is sufficiently done. To demonstrate the effectiveness of the proposed hierarchical controller, simulation studies have been performed on a microgrid consisting of four units of distributed generation with local loads and in presence of main grid using MATLAB/SIMULINK software and validated using OPAL RT real-time digital simulator.

scholarly journals Reduced Output Fluctuations of Hybrid System using SCIG by Fuzzy Logic Controller

2019 ◽  
Vol 8 (3) ◽  
pp. 7660-7663
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Reactive Power ◽  
Nonlinear Load ◽  
Integral Control ◽  
Output Fluctuations ◽  
Linear Load ◽  
Control Scheme ◽  
Proportional Integral Control ◽  
Squirrel Cage Induction Generator

In this paper, the Squirrel Cage Induction Generator(SCIG) with distinct controllers to deal with a hybrid wind hydro scheme is employed. In order to reduce the output power fluctuations in SCIG, including energy storage in the battery, a fuzzy logic controller is proposed. This controller smoothens the reactive power to the supplied load by the wind generator. The proposed controller has faster convergence compared with usual PI controller under the presence of parametric variations and uncertainties. From literature, the control scheme as many controllers operates on the Proportional Integral control, which is easy to enforce and performs well under linear conditions of load. But the proposed controller operates not only linear load but also under nonlinear load conditions. Simulation results show the robustness of the proposed controller in eliminating the harmonics, efficiency and minimizing peak oscillations of the output voltage when compared with the conventional controller.

Fuzzy Logic Controller for Force Feedback Control of Quadcopter via Tether

2020 ◽  
Author(s):  
Bennett Breese ◽  
Drew Scott ◽  
Shraddha Barawkar ◽  
Manish Kumar
Keyword(s):  
Fuzzy Logic ◽  
Control Strategy ◽  
Fuzzy Logic Controller ◽  
Force Feedback ◽  
Power Transmission ◽  
Extensive Simulation ◽  
Control Scheme ◽  
Area Surveillance ◽  
Simulation Results ◽  
Long Endurance

Abstract Tethered drone systems can be used to perform long-endurance tasks such as area surveillance and relay stations for wireless communication. However, all the existing systems use tethers only for data and power transmission from a stationary point on the ground. This work presents a control strategy that enables a quadcopter to follow a moving tether anchor. A force feedback controller is implemented using Fuzzy Logic. Using force-based strategy provides effective compliance between the tether’s anchor and the drone. The drone can thus be controlled by mere physical movement/manipulation of tether. This enhances the safety of current tethered drone systems and simplifies the flying of drones. Fuzzy Logic provides an intuitive edge to the control of such systems and allows handling noise in force sensors. Extensive simulation results are presented in this paper showing the effectiveness of the proposed control scheme.

MUSCLE RELAXATION CONTROLLED BY AUTOMATED ADMINISTRATION OF CISATRACURIUM

2006 ◽  
Vol 18 (06) ◽  
pp. 284-295 ◽  
Author(s):  
CHEN-TSE CHUANG ◽  
SHOU-ZEN FAN ◽  
JIANN-SHING SHIEH
Keyword(s):  
Fuzzy Logic ◽  
Time Delay ◽  
Automatic Control ◽  
Fuzzy Logic Controller ◽  
Muscle Relaxation ◽  
Manual Control ◽  
Logic Control ◽  
Long Term Effect ◽  
Clinical Control ◽  
The Mean

In this paper, the muscle relaxant agent (i.e., cisatracurium) and three clinical control methods (i.e., 13 patients undergoing intermitted bolus control, 15 patients undergoing intensive manual control and 15 patients) undergoing automatic fuzzy logic control (FLC), were used for maintaining depth of muscle relaxation (DOM) during surgery. Cisatracurium, a muscle relaxation drug with long-term effect, low metabolic loading, but long delay time, is widely used in operating rooms and ICUs. Meanwhile, the rules for the FLC were developed from the experimental experience of intensive manual control after learning from 15 patient trials. According to experts' experimental experience, our FLC inputs were chosen from T1% error and trend of T1% which differ from other previous studies on eliminating the effect of time delay from cisatracurium. In individual clinical experimental results, the mean(SD) of the mean T1% error in 13 patients for intermitted bolus control, in 15 patients for intensive manual control, and in 15 patients for automatic control was 8.76(1.46), 1.65(1.67), and 0.48(1.43), respectively. The t test results show that automatic control is not significantly different from intensive manual control. The results show that a simple fuzzy logic controller derived from anesthetists ' clinical trials can provide good accuracy without being affected by the pharmacological time delay problem.

scholarly journals Optimal Power Flow Using Adaptive Fuzzy Logic Controllers

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Abdullah M. Abusorrah
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Set ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Fuzzy Logic Controller ◽  
Test System ◽  
System Stability ◽  
Main Function ◽  
Adaptive Fuzzy ◽  
Adaptive Fuzzy Logic

This paper presents an approach for optimum reactive power dispatch through the power network with flexible AC transmission systems (FACTSs) devices, using adaptive fuzzy logic controller (AFLC) driven by adaptive fuzzy sets (AFSs). The membership functions of AFLC are optimized based on 2nd-order fuzzy set specifications. The operation of FACTS devices (particularly, static VAR compensator (SVC)) and the setting of their control parameters (QSVC) are optimized dynamically based on the proposed AFLC to enhance the power system stability in addition to their main function of power flow control. The proposed AFLC is compared with a static fuzzy logic controller (SFLC), driven by a fixed fuzzy set (FFS). Simulation studies were carried out and validated on the standard IEEE 30-bus test system.

scholarly journals Decentralized Fast Delayed Signal Cancelation Secondary Control for Low Voltage Ride-Through Application in Grid Supporting Grid Feeding Microgrid

2021 ◽  
Vol 9 ◽  
Author(s):  
Elutunji Buraimoh ◽  
Innocent E. Davidson ◽  
Fernando Martinez-Rodrigo
Keyword(s):  
Low Voltage ◽  
Hierarchical Control ◽  
Voltage Regulation ◽  
Power Sharing ◽  
Primary Control ◽  
Distributed Energy ◽  
Secondary Control ◽  
Low Voltage Ride Through ◽  
Control Scheme ◽  
Real Time Digital Simulator

In this study, a distributed secondary control is proposed alongside the conventional primary control to form a hierarchical control scheme for the Low Voltage Ride-Through (LVRT) control and applications in the inverter-based microgrid. The secondary control utilizes a fast Delayed Signal Cancelation (DSC) algorithm for the secondary control loop to control the reactive and active power reference by controlling the sequences generated. The microgrid consists of four Distributed Energy Resources (DER) sources interfaced to the grid through interfacing inverters coordinated by droop for effective power-sharing according to capacities. The droop also allows for grid supporting application for microgrid’s participation in frequency and voltage regulation in the main grid. The proposed decentralized fast DSC performance is evaluated with centralized secondary and traditional primary control using OPAL-RT Lab computation and MATLAB/SIMULINK graphical user interface for offline simulations and real-time digital simulator verification. This study presents and discusses the results.

scholarly journals Design and Performance Analysis of Grid Connected Solar Power System by Fuzzy Control Algorithm

2019 ◽  
Vol 8 (4) ◽  
pp. 10078-10082
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Solar Power ◽  
Vital Role ◽  
Voltage Source ◽  
Current Harmonics ◽  
Load Demand ◽  
Control Scheme ◽  
And Performance ◽  
Fuzzy Control Algorithm

In this paper we propose the fuzzy logic controller based solar fed grid via various loads. Normally present situation solar power play a vital role to meet the load demand. Solar power is the free from pollution and cost free fuel so in this paper I propose the solar based grid integrated framework, it consist of dc-dc boost converter, 3-phase voltage source inverter and fed to grid via various loads. MPPT based fuzzy logic controller is used to obtain the maximum power from the solar. But our proposed solar generation is intermittent in nature so before supplying this power to the load as well as grid we can control and enhance the power quality by utilizing FLC. This FLC control scheme effectively controls the harmonics developed in the grids. Current harmonics and Voltage flickers developed in the PV integrated grid due to non linear loads and critical loads present in the network. The proposed system is verified in MATLAB/SIMLINK.

scholarly journals Efficiency Maximization of Grid-Connected Tidal Stream Turbine System: A Supervisory Energy-Based Speed Control Approach with Processor in the Loop Experiment

2021 ◽  
Vol 13 (18) ◽  
pp. 10216
Author(s):  
Youcef Belkhier ◽  
Nasim Ullah ◽  
Ahmad Aziz Al Alahmadi
Keyword(s):  
Fuzzy Logic ◽  
Closed Loop ◽  
Fuzzy Logic Controller ◽  
High Efficiency ◽  
Reactive Power ◽  
Control Method ◽  
Speed Control ◽  
Power Converter ◽  
Convergence Criterion ◽  
Dc Voltage

Permanent magnet synchronous generator (PMSG) with a back-to-back power converter is one of the commonly used technologies in tidal power generation schemes. However, the nonlinear dynamics and time-varying parameters of this kind of conversion system make the controller computation a challenging task. In the present paper, a novel intelligent control method based on the passivity concept with a simple structure is proposed. This proposed strategy consists of passivity-based speed control (PBSC) combined with a fuzzy logic method to address the robustness problems faced by conventional control techniques such as proportional-integral (PI) control. The proposed method extracts the maximum power from the tidal energy, compensates for the uncertainty in a damped way where the entire dynamics of the PMSG are considered when designing the control law. The fuzzy logic controller is selected, which makes the proposed strategy intelligent to compute the damping gains to make the closed-loop passive and approximate the unstructured dynamics of the PMSG. Thus, the robustness property of the closed-loop system is considerably increased. The regulation of DC voltage and reactive power to their desired values are the principal objectives of the present work. The proposed method is used to control the machine-side converter (MSC), while a conventional PI method is adopted to control the grid-side converter (GSC). Dynamic simulations show that the DC voltage and reactive power errors are extremely reduced with the proposed strategy; ±0.002 for the DC-link voltage and ±0.000015 in the case of the reactive power. Moreover, the lowest steady-state error and better convergence criterion are shown by the proposed control (0.3 × 10−3 s). Generally, the proposed candidate offers high robustness, fast speed convergence, and high efficiency over the other benchmark nonlinear strategies. Moreover, the proposed controller was also validated in a processor in the loop (PIL) experiment using Texas Instruments (TI) Launchpad.

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