520 research outputs found
Ancillary services provided by residential ESSs in LV networks: Assessing the opportunity costs
No full textThe increasing penetration of distributed generation in LV distribution systems brings new challenges for distribution system operators (DSOs). For instance, the unpredictable generation of photovoltaic (PV) units may increase the effort of DSO in maintaining the demand/supply balance in the network. To this end, co-located energy storage systems (ESSs) can be a precious resource for improving the operation of PV units and increasing self-consumption of solar energy. On the other hand, DSO can take advantage of these assets by envisaging an ancillary service for improving voltage profiles based on the ability of ESSs to shift local demand/generation from a period to another period in time. To identify a fair remuneration for customers involved in providing the proposed ancillary service, we assess the opportunity cost of the forgone alternative: the cost of not self-consume solar energy. The proposal is tested on a typical LV Italian distribution network considering different scenarios and policies
Genetic Algorithm for Distribution Network Planning in presence of Distributed Generation
No full text
Quantification of variable effects of demand response resources on power systems with integrated energy storage and renewable resources
No full textThis paper reports on the quantification of the variable effects of the integration of demand response resources (DRRs) in a power system with integrated renewable energy sources (RESs) and utility-scale energy storage systems (ESSs) with the various sources of uncertainty explicitly represented. We deploy a stochastic simulation approach based on Monte Carlo techniques to emulate the transmission-constrained hourly day ahead markets (DAMs) over longer term periods. Salient characteristics of the approach are the ability to represent the spatial and temporal correlation of the loads and the renewable resources, the ability to explicitly represent the payback characteristics of DRRs and the deployment of effective strategies to provide computational tractability for large-scale grids. We illustrate the application of the approach to a modified version of the WECC 240 bus-system to perform various study cases to evaluate the economics, emissions and reliability metrics. The studies illustrate the strong capabilities of the approach and provide insights into the impacts of deepening penetration of DRRs under different intensity levels
A Fuzzy Logic Controller to Increase Fault Ride-Through Capability of Variable Speed Wind Turbines
No full textA fuzzy controller for improving Fault Ride-Through (FRT) capability of Variable Speed Wind Turbines (WTs) equipped with Doubly Fed Induction Generator (DFIG) is presented. The controller is designed in order to compensate the voltage at the Point of Common Coupling (PCC) by regulating the reactive and active power generated by WTs. The performances of the controller are evaluated in some case studies considering a different number of wind farms in different locations. Simulations, carried out on a real 37-bus Italian weak distribution system, confirmed that the proposed controller can enhance the FRT capability in many cases
Design and implementation of a fuzzy controller for wind generators performance optimisation
No full textA comparison among reactive power compensation strategies in wind farm power plant
No full textSquirrel cage induction generators are consolidated technologies for wind energy. Nevertheless, they do not perform voltage regulation and absorb reactive power from the utility grid. In this paper a comparison among three different reactive power compensation strategies is presented: centralized, fully decentralized and partially decentralized. The last is the proposal developed in the paper where an optimization problem is solved to individualize optimal sizing and location of reactive power centres. The problem is tested by a case study on a real test grid and encouraging results are presented
- …
