Search results for "distributed generation"

Modelling of a prosumer’s substation in a district heating network: validation and dynamic analysis

Thermal grids will play a key role in the development of local energy communities and the achievement of 100% renewable societies. However, challenges are related to the capability of dealing with the increasing number of producers which could supply heat to thermal grids. Indeed, as in the case of the electricity grid, heat could be available for some hours in a day from RES plants installed at user level and distributed in the network (also referred to as “prosumers”). To achieve more reliable results when performing energy analyses of these innovative applications, there is a need to rely on accurate models of each component. For instance, substations are of paramount importance in the i…

Optimal Operating Point Calculation for Medium Voltage Distribution Systems

2007

The paper deals with the calculation of the optimal working point of a distribution system, equipped with several distributed generators, able to operate also autonomously, i.e. disconnected from the main grid. When connected to the main grid, it appears in general convenient to assign the slack bus role to the bus that represents such a connection. The problem becomes more complex when maximum power transfer constraints through the connection must be taken into account. The adequate slack bus treatment is even more important when the optimal operating condition must refer to the condition subsequent to an intentional or unintentional disconnection from the main grid. The paper presents an …

Coupled hydraulic and electronic regulation of cross-flow turbines in hydraulic plants

2017

The potential benefit of coupling hydraulic and electronic regulation to maximize the energy production of a cross-flow turbine in hydraulic plants is analyzed and computed with reference to a specific case. Design criteria of the cross-flow turbine inside hydraulic plants are first summarized, along with the use of hydraulic regulation in the case of constant water head and variable discharge. Optimal turbine impeller rotational speed is derived, and traditional as well as innovative systems for electrical regulation are presented. A case study is analyzed to evaluate the potential energy production according to the expected monthly mean flow distribution and two possible choices: CFT1 wit…

Smart interface devices for distributed generation in smart grids: The case of islanding

2017

With the increasing presence of distributed generators (DGs), the implementation of a smart sensors and actuators network in distribution grids has become crucial for different monitoring, management and protection functionalities. For DGs monitoring and control, sensors and actuators are usually embedded in so-called interface devices (IDs) or interface protection systems (IPSs). Existing IDs lack in communication interfaces both to the electrical energy Distribution System Operators (DSOs) and to the DGs inverter. In this framework, the authors have developed a new ID solution and a proper communication architecture, which allow implementing new smart functionalities based on the interact…

Fault Tolerant Ancillary Function of Power Converters in Distributed Generation Power System within a Microgrid Structure

2013

Distributed generation (DG) is deeply changing the existing distribution networks which become very sophisticated and complex incorporating both active and passive equipment. The simplification of their management can be obtained assuming a structure with small networks, namely, microgrids, reproducing, in a smaller scale, the structure of large networks including production, transmission, and distribution of the electrical energy. Power converters in distributed generation systems carry on some different ancillary functions as, for example, grid synchronization, islanding detection, fault ride through, and so on. In view of an optimal utilization of the generated electrical power, fault to…

Control and power management of Photovoltaic-battery based micro grid

2016

The growing demand for electrical power and the interruption of the power supply has paved the way for the realization of renewable based energy generation. This paper presents the control and power management of a hybrid microgrid system that comprises Photovoltaic (PV) array, battery, and local AC load, connected to the utility grid. This work focuses on the compensation of PV power reduction due to partial shading using bidirectional half bridge converter with battery storage. This system considers fulfilling the local load demand through PV production and, then, to manage the power among the battery and grid. In the proposed system, the considered power conditioning devices area boost c…

Coupled Hydraulic and Electronic Regulation for Banki Turbines

2016

Abstract The potential benefit of coupling hydraulic and electronic regulation to maximize the energy production of a Bank turbine in hydraulic plants is analyzed and computed with reference to a specific case. Design criteria of the Banki turbine inside hydraulic plants are first summarized, along with the use of hydraulic regulation in the case of constant water head and variable discharge at the end of aqueducts feeding water distribution systems. Optimal turbine impeller rotational speed is derived and traditional, as well as innovative systems for electricity production according to controlled rotational speed of the generator are presented. The study case at the purification plant nam…

Applications of the Fault Decoupling Device to Improve the Operation of LV Distribution Networks

2008

The aim of this paper is to present the operating principle of a new resonant device, called the fault decoupling device (FDD), able to improve power quality in electrical distribution systems. In low-voltage networks, this device can be employed in order to mitigate voltage dips due to faults or large induction motor startup. Moreover, in the presence of distributed-generation (DG) units, the FDD allows one to obtain various benefits such as a reduction of the fault current in each node of the network and an increase in the voltage at the DG unit node. In order to show the performances of the FDD, analytical studies and computer simulations were carried out which took into account various …

Microgrid supervisory controllers and energy management systems:A literature review

2016

Abstract Microgrids (MGs), featured by distributed energy resources, consumption and storage, are designed to significantly enhance the self-sustainability of future electric distribution grids. In order to adapt to this new and revolutionary paradigm, it is necessary to control MGs in intelligent and coordinated fashion. To this aim, a new generation of advanced Microgrid Supervisory Controllers (MGSC) and Energy Management Systems (EMS) has emerged. The aim of this paper is to summarize the control objectives and development methodologies in the recently proposed MGSC/EMS. At first, a classification of control objectives is made according to the definition of hierarchical control layers i…

Investigating the effect of distributed generators on traditional protection in radial distribution systems

2013

The recent changes in power network structure, development in green energy technologies and increased attention on environmental concerns have led to increase the installation of renewable energy based distributed generations (DG) in distribution networks. The increasing penetration of distributed generation in the distribution power system creates new technical and economical challenges; protection is one important topic of these challenges. High penetration of DG will have unfavorable impact on the traditional protection methods; the impact depends on the number, location and size of injected DG. To ensure safe and selective protection devices coordination, the impact of DG should be take…