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A distinctive characteristic of a Microgrid (MG) system is related to the ability of operating autonomously. However, the stability of the system relies in storage and generation availability, providing frequency and voltage regulation. Considering the deployment of distributed storage units in the Low Voltage network and of smart metering infrastructures, this paper presents an online tool for promoting...
The aim of this paper is to explain a novel technique to improve voltage and frequency profiles on microgrids controlled using the droop control scheme. The method consists on retuning the controller according to the present load scenario by adjusting the droop coefficients in a way that is proportional to the load changes. The proposed technique is tested through numerical simulations and the results...
This study examines the P+ multi resonant based voltage control for the voltage harmonics compensation under the islanded mode of a microgrid. In islanded mode, the inverter is defined as a voltage source to supply the full local load demand without a connection to the grid. On the other hand, the output voltage waveform is distorted by the negative and zero sequence and current harmonics due to the...
The article define set of rules for future Electricity market structure, taking into account network codes, legislation and directives to ensure RES integration targets and Energy Union Dimensions in term of a fully integrated internal energy market and transition to a long lasting low-carbon society. Presented research studies are based on new way of power system operation development, namely Web-of-cell...
This paper proposes a novel control scheme for frequency support among asynchronous AC areas through HVDC grids. It is based on local controllers, each acting on a voltage source converter, using locally available measurements only, and supporting frequency of the adjacent AC area after a significant disturbance. The controller is combined with the existing DC voltage droop technique and is inspired...
Many efforts have been made to improve the performance of power electronic systems with active capacitive DC-link module in terms of power density as well as reliability. One of the attractive solution is an active capacitive DC-link with the series-connected circuit because of handling small-rated power. However, in the existing control method of this circuit, the DC-link current of the backward-stage...
A novel variable frequency variable duty cycle (VFVD) control scheme using off-line digital control by only sensing the output voltage is proposed. Designed for a 6 kV 40 kHz series resonant DC-DC converter in solid state transformer application, it realizes cycle-by-cycle resonant current limiting and zero voltage switching (ZVS) at any load condition. According to the state plane analysis, with...
In this demonstration, we present a frequency-based system serving as the stimulator for biocompatible ionic electroactive polymers (iEAPs). We will demonstrate that we can wirelessly tune both the magnitude and the polarity of the voltage provided by the stimulator, by changing the frequency of the input signal, to control the degree and the direction of the movement of iEAPs.
Microgrids are key elements for integrating renewable resources as well as distributed energy storage systems as green sources of electricity. However, the presence of controllers is indispensable in confronting the intermittency and variable operation of renewable resources. This paper explores the control of active and reactive power flow through two modes of microgrid operations, namely islanded...
Variable frequency drives are widely used in industrial enterprises and are therefore an influential part of electric load. The aim of this study was to define a relation between voltage unbalance and variable frequency drive power. The mathematical models of drives with a cycloconverter and the frequency converter with a DC link (independent current and voltage inverter) were elaborated. Mathematical...
The paper is focused on technical performance and design of the thyristor voltage converter (TVC) with an adaptive control system for a smooth start of induction motors and a power semiconductor thyristor-diode. A distinctive feature of ab adaptive TVC is that its pulse-phase control system is based on closed integrating scanning converters (SCs). All SCs operate in an external synchronization mode...
The present article describes the implementation of Battery energy storage system (BESS) for improved and better performance characteristics of load frequency control problem with a compact sized battery energy storage system (BESS) with respect to load frequency control (LFC) applications. It is observed there is significant reduction in the frequency deviations. Also tie-power variations get diminished...
The low and medium frequency signal generator with high precision and high stability is widely used in experiment courses, mechanical, engineering and other fields. In order to meet the special needs of these fields, this paper puts forward a design scheme of signal generator based on DDS. Combined with the advantage of virtual instrument technology, the user can set the signal parameters on PC control...
The increasing awareness of the need to reduce pollution and global warming, and the increasing price of conventional energy resources, encouraged many countries to adapt new energy policies by including renewable energy resources, such as solar energy, wind energy, tidal energy. These new energy sources are usually connected to the gird via inverters, which presents fast dynamics due to their small...
As one type of general power converter, matrix converter can realize n phase to m phase voltage conversion, the control strategy of which is now a research hotspot. For three input and one output phase matrix converter (31MC), in view of the insufficiency of normal strategies, a control strategy is adopted based on the hysteresis current control technology. Moreover, aimed at the contradiction between...
Lately, new solutions have been added to the control of autonomous grids, which improve the way the power grids operate. These changes may affect the reliability and safety of power distribution grids, the dynamic stability being a real concern. This issue is more prominent in autonomous microgrids (MGs) with high penetration of renewable energy sources. On this topic, this paper aims to study how...
In order to improve the starting torque of the soft start of the asynchronous motor and reduce the starting current, a soft starting method from the second frequency to the power frequency starting is proposed. On the basis of this theory, the simulation model of soft start system of asynchronous motor graded frequency conversion control is built by Simulink simulation function of MATLAB. The simulation...
Nano-robotic systems based on Piezoelectric StickSlip (PSS) actuators have become increasingly popular in research and industry for semi-automated and automated tasks at small scales. For an efficient use of PSS actuators, a series of research have been fulfilled on design process, dynamic modeling, driving methods and position control. However, there have been very few investigations on velocity...
This paper presents an off-board trajectory controller for a range of stride frequencies (2–45 Hz) that enables zero-radius turns and holonomic control on one of the smallest and fastest legged robots, the Harvard Ambulatory MicroRobot (HAMR). An experimental model is used as the basis for control to capture the highly nonlinear response of the robot to input signals. Closed-loop trajectories are...
This paper presents seamless transiton between the grid-connected and islanded mode of microgrid. The prominenece of the seamless transition is to maintain the load voltage and frequency as well as constant power delivery during both the modes of operation of microgrid. In this paper voltage source converter (VSC) of PV generating unit operates in PQ control mode in both grid-tied and islanded operation...
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