Pico-hydro systems: microgrid-connection approaches

Small hydropower systems are considered an environmentally friendly energy option. They have a huge untapped potential which allows them to make a more significant contribution to future energy demand with many advantages. The integration of pico-hydro systems into microgrids is an emerging solution for the electrification of remote areas and for self-sustainable power systems. This paper presents and discusses the three main grid connection approaches for pico-hydro systems focused on the integration in small microgrids: using specifically designed power converters, using standard wind inverters and using standard photovoltaic inverters. These latest approaches based on conventional inverters are able to explore a large amount of feasible sites with low-head and very low-head. They improve efficiencies, reduce costs and environmental impacts and improve reliability. Experimental evaluation of the performance in steady-state and in dynamic conditions proves the feasibility of these innovative approaches.info:eu-repo/semantics/publishedVersio

Compatibility analysis of grid-connected pico-hydro systems using conventional photovoltaic inverters

Small scale hydropower has a considerable untapped potential, able to contribute to the increased energy demand. The integration of these systems into microgrids is an emerging solution for the electrification of remote areas and for self-sustainable power systems. This paper is devoted to the design optimization of grid-connected pico-hydro systems using conventional photovoltaic inverters, providing cost effective solutions able to explore a large amount of feasible sites. Experimental tests of the proposed innovative topology with two inverters and selected generators were performed, evaluating the performance in steady state and dynamic conditions, corroborate the proposed design procedure.info:eu-repo/semantics/publishedVersio

Analysis of the operation of a microgrid with renewable distributed generation

This article reports the ongoing research on the performance assessment of an experimental microgrid which integrates various renewable energy sources. The microgrid is based on a modular commercial solution, up to a rated power of 5 kW, integrating storage devices, a backup diesel generator and various renewable energy sources and also distributed energy sources developed under ongoing R&D projects, such as the integration of a pico hydropower plant with an interface able to perform power factor compensation of the microgrid, which is introduced briefly. The performance assessment of this microgrid is conducted through a characterization of different operational states and also a preliminary energy balance of the microgrid during a time span of 4 days.The authors would like to acknowledge the financial support provided by the European Regional Development Fund, under the Interreg Project 0128_PROBIOENER_2_E.info:eu-repo/semantics/publishedVersio

Grid-connection approaches for pico-hydro systems

Small hydropower systems are considered an environmentally friendly energy option. They have a huge untapped potential which allow it to make a more significant contribution to future energy demand with many advantages. Grid-connected pico-hydro systems are an emerging solution for application in a huge number of applications such as in household water supply, wastewater treatment facilities and to improve control systems and optimize generation as a part of integrated water management systems. They are also very promising for integration in microgrids in many developing countries. This paper presents and discusses the main three grid-connection approaches for pico-hydro systems: using specifically designed power converters; using standard wind inverters; and using standard photovoltaic inverters. These latest approaches based on conventional inverters are practical solutions able to explore a large amount of feasible sites with low-head and very low-head. Moreover, photovoltaic micro inverters, recently launched in the market, are propose for very low power generators (250-300 W). These approaches improve efficiencies, reduce costs and environmental impacts and improve reliability. Experimental evaluation of the performance in steady-state and in dynamic conditions proves the feasibility of these innovative approaches.info:eu-repo/semantics/publishedVersio

A practical approach for grid-connected pico-hydro systems using conventional photovoltaic inverters

Pico-hydro power generation has a considerable untapped potential, able to contribute to the increased energy demand whilst ensuring a low environmental impact. The integration of these systems into microgrids is an emerging solution for the electrification of remote regions and also for selfsustainable power systems. The integration of cheap and wide spread technologies to interface small capacity hydro power systems with the grid has become essential in order to enable the exploitation of small rivers and shallows reservoirs resources among many other applications such as in water supply systems. This paper presents a design procedure to integrate pico-hydro generators into the grid using conventional and widespread photovoltaic inverters.info:eu-repo/semantics/publishedVersio

Bidirectional vehicle-to-grid interface under a microgrid project

In the emergent deployment of smart grids, storage systems play an important role into assets utilization optimization, providing backup power and peak-shaving. This concept becomes more critical in the context of microgrids with a high penetration of renewable energy resources. Plug-in electric vehicles provide an enormous distributed storage capability, which favours the technical and economical exploitation of such systems. This paper presents a comprehensive implementation and control of a bidirectional power converter for vehicle-to-grid integration, based on a bidirectional DC/DC converter followed by a full bridge DC/AC converter.info:eu-repo/semantics/publishedVersio

On the implementation of a microgrid project with renewable distributed generation

This paper describes the on-going implementation of a microgrid project with renewable distributed generation under the context of an initiative with demonstration purposes in an university campus. In the actual context of the electrical energy demand increase and limited conventional resources, along with the consciousness of the climate changes and the need to invest in clean energies, microgrids allows the integration of dispersed energy sources, mainly renewable, which make them cost effective, providing a viable alternative to centralized production, transmission and distribution system for remote community areas. The design concept of the microgrid and a description of the base equipment and energy sources already integrated are presented. From the on-going projects to be integrated on the microgrid, it is presented the Grid-to- Vehicle and Vehicle-to-Grid concept, which will provide a second energy storage element using the battery of an electric vehicle. To accomplish this objective, a bi-directional power converter is being developed and simulation results of its power structure and control are presented

Improving the storage capability of a microgrid with a vehicle-to-grid interface

In the emergent deployment of microgrids, storage systems play an important role providing ancillary services, such as backup power and reactive power support. This concept becomes crucial in the context of microgrids with a high penetration of renewable energy resources, where storage systems may be used to smooth the intermittency and variability of most of them. Plug-in electric vehicles provide an enormous distributed storage capability, which favours the technical and economical exploitation of such systems. This paper presents a comprehensive implementation and control of a bidirectional power converter for Vehicle-to-Grid integration, based on a bidirectional DC/DC converter followed by a full bridge DC/AC converter. The evaluation of the adopted topology and its control is performed through MATLAB/Simulink simulation.info:eu-repo/semantics/publishedVersio

A low cost induction motor controller for light electric vehicles in local areas

This paper is concerned with design considerations and tradeoffs involved in the power electronics development for light electric vehicles. A review of propulsion system design, power conversion structure and control is presented. A three-phase squirrel-cage induction motor is used as propulsion system for an electric scooter. The motor is controlled at different operating conditions by means of a simple scalar control using a low cost controller board developed for light electric vehicles used in local areas. Experimental results show that the proposed digital controller is able to follow the reference speed with a suitable dynamics for the electric scooter