Implement an efficient multi-loop control scheme using rapid estimating filters to compensate for a variety of voltage drops

2021 ◽  
Author(s):  
Hossein Mirzanejad ◽  
Shahaboddin Sadeghi ◽  
Ehsan Salajegheh
Keyword(s):  
Loop Control ◽  
Voltage Drops ◽  
Control Scheme

scholarly journals Automatic locking of a parametrically resonating, base-excited, nonlinear beam

2021 ◽  
Author(s):  
Nir Ben Shaya ◽  
Izhak Bucher ◽  
Amit Dolev
Keyword(s):  
Relative Phase ◽  
Closed Loop ◽  
Dynamical Behavior ◽  
Open Loop ◽  
Vibration Modes ◽  
Nonlinear Structure ◽  
Nonlinear Beam ◽  
Loop Control ◽  
Control Scheme ◽  
Slender Beams

AbstractDescribed is a closed-loop control scheme capable of stabilizing a parametrically excited nonlinear structure in several vibration modes. By setting the relative phase between the spatially filtered response and the excitation, the open-loop unstable solution branches are stabilized under a 2:1 parametric excitation of a chosen mode of vibration. For a given phase, the closed-loop automatically locks on a limit cycle, through an Autoresonance scheme, at any desired point on the solution branches. Axially driven slender beams and nanowires develop large transverse vibration under suitable amplitudes and frequency base-excitation that are sensitive to small potential coupled field. To utilize such a structure as a sensor, stable and robust operation are made possible by the control scheme. In addition, an optimal operating point with large sensitivity to the sensed potential field can be set using phase as a tunable parameter. Detailed analysis of the dynamical behavior, experimental verifications, and demonstrations sheds light on some features of the system dynamics.

Modeling and Control of a Rotary Crane

1985 ◽  
Vol 107 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Y. Sakawa ◽  
A. Nakazumi
Keyword(s):  
Feedback Control ◽  
Equilibrium State ◽  
Open Loop ◽  
The State ◽  
Control Input ◽  
Loop Control ◽  
Modeling And Control ◽  
Control Scheme ◽  
Rotary Crane ◽  
And Control

In this paper we first derive a dynamical model for the control of a rotary crane, which makes three kinds of motion (rotation, load hoisting, and boom hoisting) simultaneously. The goal is to transfer a load to a desired place in such a way that at the end of transfer the swing of the load decays as quickly as possible. We first apply an open-loop control input to the system such that the state of the system can be transferred to a neighborhood of the equilibrium state. Then we apply a feedback control signal so that the state of the system approaches the equilibrium state as quickly as possible. The results of computer simulation prove that the open-loop plus feedback control scheme works well.

Inductive Reheating of Steel Billets into the Semi-Solid State Based on Pyrometer Measurements

2006 ◽  
Vol 116-117 ◽  
pp. 734-737 ◽  
Author(s):  
Alexander Schönbohm ◽  
Rainer Gasper ◽  
Dirk Abel
Keyword(s):  
Solid State ◽  
Measurement Errors ◽  
Liquid Fraction ◽  
Solidus Temperature ◽  
Measurement Data ◽  
Heating Process ◽  
Production Environment ◽  
Loop Control ◽  
Control Scheme ◽  
Semi Solid

The aim of the paper is to demonstrate a control scheme by which it is possible to reproducibly reheat steel billets into the semi-solid state. Usually a heating program is used to reheat the billet into the semi-solid state. Our experiments showed that this control scheme leads to varying semi-solid fractions from one experiment to the next. To gain information about the billet’s state its temperature is often used since there is a known relationship between the temperature and the liquid fraction. Direct measurement of the temperature via thermocouples is not feasible in a production environment, therefore a radiation pyrometer has been used as a contact-less measurement device. The accuracy of the pyrometer depends heavily on the exact knowledge of the radiation coefficient, which can vary from billet to billet due to different surface properties and which is subject to change during the heating process. These uncertainties prohibit the implementation of a closed-loop control scheme since the exact temperature cannot be measured with the required accuracy. In order to be independent of the measurement errors the proposed control scheme only relies on the slope of the temperature. By detecting the distinct change of slope which occurs when the solidus temperature is crossed, the beginning of the melting process can be determined. The energy fed to the billet from this point onward determines the resulting liquid fraction. By detecting the entry into the solidusliquidus interval and then feeding the same amount of energy to each billet, it is guaranteed that the billet reaches the desired liquid fraction even by uncertain absolute value of the temperature and by small variations of the alloy composition. For the experiments the steel alloy X210 has been used and measurement data demonstrate the feasibility of the proposed control scheme.

Analysis and Implementation of a High Boost Ratio DC-DC Converter for Minimizing Commutation Torque Ripple in Brushless DC Motor

2016 ◽  
Vol 7 (2) ◽  
pp. 583
Author(s):  
M. Senthil Raja ◽  
B. Geethalakshmi
Keyword(s):  
Closed Loop ◽  
Torque Ripple ◽  
Dc Motor ◽  
Duty Ratio ◽  
Brushless Dc Motor ◽  
Loop Control ◽  
Brushless Dc ◽  
Control Scheme ◽  
Converter Topologies ◽  
Commutation Torque Ripple

Brushless dc motor still suffers from commutation torque ripple, which primarily depends on transient line current in the commutation interval. In order to control the incoming and outgoing phase currents to change at the same rate during commutation, this paper presents a novel high boost ratio DC-DC circuit topology in the front end of the inverter. With a suitable closed loop control scheme, the proposed high boost ratio DC-DC converter is operated with two different duty ratios one during commutation period and the other during non commutation period. The cause of commutation ripple is analyzed, and the way to adjust the duty ratio for obtaining the desired dc link voltage is introduced in detail. Finally, simulation and experimental results show that, compared with the existing dc–dc converter topologies, the proposed method can obtain the desired voltage much faster and minimize commutation torque ripple more efficiently

scholarly journals Adaptive-Observer-Based Data Driven Voltage Control in Islanded-Mode of Distributed Energy Resource Systems

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3299 ◽  
Author(s):  
Yan Xia ◽  
Yuchen Dai ◽  
Wenxu Yan ◽  
Dezhi Xu ◽  
Chengshun Yang
Keyword(s):  
Energy Resource ◽  
Design Procedure ◽  
Voltage Control ◽  
Adaptive Observer ◽  
Data Driven ◽  
Distributed Energy ◽  
Control Effect ◽  
Loop Control ◽  
Distributed Energy Resource ◽  
Control Scheme

In this paper, an adaptive observer based data driven control scheme is proposed for the voltage control of dispatchable distributed energy resource (DER) systems which work in islanded operation. In the design procedure of the proposed control scheme, we utilize the novel transformation and linearization technique for the islanded DER system dynamics, which is proper for the proposed data driven control algorithm. Moreover, the pseudo partial derivative (PPD) parameter matrix can be estimated online by multiple adaptive observers. Then, the adaptive constrained controller is designed only based on the online identification results derived from the input/output (I/O) data of the controlled DER system. It is theoretically proven that all the signals in the closed-loop control system are uniformly ultimately bounded based on the Lyapunov stability analysis approach. In addition, the results of the simulation comparison are given to verify the voltage control effect of the proposed control scheme.

scholarly journals Improved Voltage Unbalance and Harmonics Compensation Control Strategy for an Isolated Microgrid

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2688 ◽  
Author(s):  
Mohammad Jafar Hadidian Moghaddam ◽  
Akhtar Kalam ◽  
Mohammad Reza Miveh ◽  
Amirreza Naderipour ◽  
Foad H. Gandoman ◽  
...  
Keyword(s):  
Control Strategy ◽  
Power Converter ◽  
Phase Model ◽  
Nonlinear Load ◽  
Loop Control ◽  
Single Input Single Output ◽  
Three Phase ◽  
Control Scheme ◽  
Unbalanced Load ◽  
Load Conditions

This paper suggests an enhanced control scheme for a four-leg battery energy storage systems (BESS) under unbalanced and nonlinear load conditions operating in the isolated microgrid. Simplicity, tiny steady-state error, fast transient response, and low total harmonic distortion (THD) are the main advantages of the method. Firstly, a new decoupled per-phase model for the three-phase four-leg inverter is presented. It can eliminate the effect of power stage coupling on control design; thus, the three-phase four-leg power inverter can be viewed as three single input single output (SISO) control systems. Then, using an improved orthogonal signal generation method, the per-phase model of the four-leg inverter in the stationary and synchronous frame is derived. As the second step, a per-phase multi-loop control scheme for the four-leg inverter under unbalanced load conditions is suggested. The proposed control strategy has the ability to provide balanced output voltages under unbalanced load conditions by avoiding the need to deal with the symmetrical components. Finally, a multi-resonant harmonic compensator is used to actively prevent low-order harmonic currents to distort the output voltages of the three-phase four-leg grid-forming power converter. Simulations results are also presented to verify the performance of the suggested control strategy.

Process Control of Laser Grooving Using Acoustic Sensing

1991 ◽  
Vol 113 (3) ◽  
pp. 268-275 ◽  
Author(s):  
G. Chryssolouris ◽  
P. Sheng ◽  
F. von Alvensleben
Keyword(s):  
Resonant Frequency ◽  
Pid Controller ◽  
Process Model ◽  
Laser Machining ◽  
Depth Of Cut ◽  
Acoustic Sensing ◽  
Loop Control ◽  
Control Scheme ◽  
Constant Area ◽  
Control Concept

This paper discusses a closed-loop control concept for laser machining. A key development in the proposed control scheme is an acoustic sensor for inferring hole, kerf, and groove geometry in real time during laser machining. By sensing the acoustic signal emitted from the impingement of a gas jet on the erosion front, correlations between resonant frequency and hole, kerf or groove geometry were found. A process model was developed from applying the wave equation to the case of an elliptically-expanding or a constant-area jet. Experiments showed an inverse relationship between depth of cut and resonant frequency for grooving, cutting, and drilling cases. The paper also includes preliminary simulation results of a closed-lop control scheme for laser grooving using acoustic sensing and a PID controller.

Control of Quasi-Z Source Inverter with Super Capacitor under Unbalanced Grid Fault Conditions

2013 ◽  
Vol 291-294 ◽  
pp. 2124-2131
Author(s):  
Feng Lin Li ◽  
Shu Ju Hu ◽  
Ling Ling Wang
Keyword(s):  
Reference Frames ◽  
Control Method ◽  
Low Voltage ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Super Capacitor ◽  
Loop Control ◽  
Control Scheme ◽  
Unbalanced Grid ◽  
Generation Unit

The quasi-Z-source inverter (qZSI) has some unique advantages and is suitable for renewable energy sources such as solar and wind generation system. In order to make the inverter have the ride-through ability and the current into the grid symmetrical when unbalanced grid faults occur, the topology of qZSI with super capacitor substituting the low voltage capacitor and the unbalance control strategy were proposed. With a super capacitor the system can balance and smooth the power between the generation unit and grid, also the current injected into the grid can be symmetrical through the unbalance control method. The circuit of the new topology and the mathematical model of the three-phase converter under grid voltage unbalance conditions have been analyzed. And then, closed-loop control scheme for the proposed system is used to control the power flow of generation unit, grid and super capacitor in this system, also unbalance control strategies in positive (dq) + and negative (dq) – reference frames have been implemented in the grid-connected qZSI system to make the current into the grid symmetrical during the grid fault. The operating mode during unbalanced grid fault is simulated in MATLAB/Simulink, and the simulation results are presented to verify the theoretical analysis and the control scheme.

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