Integration of Renewable Energy Resources in Microgrid

Microgrid is a new concept in power generation. The Microgrid concept assumes a cluster of loads and micro sources operating as a single controllable system that provides both power and heat to its local area. Not much is known about Microgrid behavior as a whole system. Some models exist which describe the components of a Microgrid. In this paper, model of Microgrids with steady state and their transient responses to changing inputs are presented. Current models of a fuel cell, microturbines, wind turbine and solar cell have been discussed. Finally a complete model built of Microgrid including the power sources, their power electronics, and a load and mains model in MATLAB/Simulink is presented.

Control and Implementation of Single-Inverter Microgrid

In this paper, simulation and implementation way for practical control of Single Inverter Microgrid (SIMG) is presented. This system is equipped by solar system, wind energy conversion system (WECS), and microturbine system. Each DG’s has controlled independently. This is a kind of decentralize control because each DG’s has difference controller. Control of Microgrid (MG) during both grid tie and islanding modes is presented. Solar system and WECS are modeled based on santerno products. This system is compared with three inverter MGs with Centralize control strategy. Controlled signals show that SIMG is more reliable and economical. THD is improved and strategy is simplified for SIMG.

Modeling, Control &Fault Management of Microgrids

In this paper, modeling and decentralize control principles of a MicroGrid (MG) whom equipped with three Distributed Generation (DG) systems (consist of: Solar Cell System (SCS), MicroTurbine System (MTS) and Wind Energy Conversion System (WECS)) is simulated. Three arrangement of load changing have investigated for the system. In first one the system doesn’t have transfer of power between MG and grid. In other two arrangements system have transfer of power between MG and utility grid. Of course in third case transfer of power between DG resources is considerable. Case study system is equipped by energy storage devices (battery bank) for each DG’s separately by means of increasing the MG reliability. For WECS and SCS, MPPT control and for MTS, voltage and frequency (V&F) controller has designed. The purpose of this paper is load respond in MG and storage process of surplus energy by consider of load changing. MATLAB/Simulink and its libraries (mainly the Sim Power Systems toolbox) were employed in order to develop a simulation platform suitable for identifying MG control requirements. This paper reported a control and op- eration of MG in network tension by applying a three phase fault.

Preliminary Design, Drive-Cycle Simulation and Energy Analysis of a Hybrid Transit Bus

Modern metropolises are increasingly affected by air quality problems. Transportation is one of the largest sources of several pollutants emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). Today in the EU, vehicles' emissions are strictly limited by Euro 6 norm-Euro VI for heavy-duty vehicles-which is periodically upgraded. To match such limits, manufacturers are forced in developing new technologies to perform new sustainable vehicles design strategies, such as EVs and HEVs. Present work's aim is to provide the design of series-hybrid urban transportation bus, equipped with a novel thermal power unit, namely a small gas turbine, to exploit its cleaner combustion process in comparison with an ICE. The control logic is described, while the main drivetrain components are chosen, and suitable models from suppliers are selected as well. Then, some simulations of the resulting vehicle are performed on opportune drive cycles, using Advisor, a free software based on Matlab-Simulink environment, published by US' National Renewable Energy Laboratory (NREL). Two different final configurations are environmentally and economically analysed, with the thermal power unit being respectively fuelled by compressed natural gas (CNG) and liquefied petroleum gas (LPG). Both satisfy the Euro VI norms, showing a substantial emission reduction (-89% and -43% in CO and THC releases respectively) in comparison to pollutants' threshold values.

Study on leakage flow characteristics of radial inflow turbines at rotor tip clearance

Tip clearance leakage flow in a radial inflow turbine rotor for microturbines under the stage environment is investigated using a three-dimensional viscous flow simulation. The results indicate that the scraping flow caused by relative motion between casing and rotor tip, and the pressure difference between pressure side and suction side at rotor tip, play important roles in tip clearance leakage flow. The more the rotor tip speed increases and tip clearance height decreases, the more the scraping effect acts. Though the leakage velocity of tip clearance at midsection and exducer regions changes less when the rotor rotational speed is changing, the distance between passage vortex and rotor suction side varies in evidence. Main leakage flow rate of tip clearance takes place at region of exducer tip and some seal configurations will be quite effective for cutting leakage flow if these configurations are arranged over midsection and exducer of the radial inflow rotor.