Search results for "Distribution network"
showing 10 items of 91 documents
Comparing the Impact of Electric Vehicles on Urban and Insular Networks
2022
Transport sector is moving towards clean and green transportation with the growing market of electric vehicles globally. Electric vehicles are independent fossil fuels consumption, but the massive adoption of electric vehicles soon can lead to a significant burden on the power distribution networks. In this paper, a study on the potential impact of electric vehicles on the power distribution networks of two different regions with totally different realities of population density, an average number of cars per inhabitant, and travel habits has been carried out. The first region is the island of Favignana having an insular power distribution network, while the other region, the city of Palerm…
Load Flow Solution of radial distribution networks with ZI loads
2008
In this paper, a methodology to solve radial distribution networks, with constant current and/or impedance loads, is proposed. The techniques currently available to solve such systems are based either on iterative methods or on the bus impedance matrix. The method developed is the extension of a technique that is valid to solve networks made of impedances with one supply point. The methodology can be applied to directly and rapidly solve large distribution systems in which the loads are modeled as constant current/impedance. It is also able to solve meshed systems having voltage-dependent loads, inside an iterative backward/forward method.
A Multi-Port Approach to Solve Distribution Networks with Meshes and PV Nodes
2007
A new methodology based on the backward/forward (b/f) technique for the load flow solution in distribution systems is here proposed. The methodology takes efficiently into account the fixed voltage nodes and uses a reduced bus impedance matrix. In this way, it is possible to attain, for the unknowns at the PV nodes, the same values that are attainable solving the network with the methods adopted for transmission systems. With the same methodology it is possible to take into account also the meshes. If the network contains only meshes, the relevant model is linear and it is the one including the compensation currents. The presence of PV nodes introduces non linearity in the model and an iter…
Load modelling influence on voltage stability assessment in distribution systems. Part II: Extension to a complex radial system and applications
2006
The single-line equivalent model is commonly used for voltage stability studies in both distribution and transmission systems. Referring to a single-line system, in the companion paper [1] the authors presented the theoretical aspects of voltage stability related to the load characteristics. In particular, expressions of the stability index for constant power, constant impedance and constant current loads, singularly and in all the possible combinations have been obtained. This index indicates how far the load node is from its voltage collapse point, allowing the maximum load power beyond which voltage collapse takes place to be evaluated. In this paper a simple method to evaluate the param…
Load modelling influence on voltage stability assessment in distribution systems. Part I: Stability index and critical power for a single-line system
2006
The single-line equivalent model is commonly used for voltage stability studies in both distribution and transmission systems. Referring to a single-line system, in the companion paper [1] the authors presented the theoretical aspects of voltage stability related to the load characteristics. In particular, expressions of the stability index for constant power, constant impedance and constant current loads, singularly and in all the possible combinations have been obtained. This index indicates how far the load node is from its voltage collapse point, allowing the maximum load power beyond which voltage collapse takes place to be evaluated. In this paper a simple method to evaluate the param…
An improved method for determining voltage collapse proximity of radial distribution networks
2005
The two-bus equivalent model is commonly used for voltage stability studies in both distribution and transmission systems. The paper presents a simple method to evaluate, for each bus, the parameters which define the equivalent circuit of a radial distribution network. In particular, a straightforward way for determining the Thévenin equivalent impedance behind a load node is proposed, which allows to better identify the maximum loading point beyond which the voltage collapse takes place in the network. Simulation results show that the proposed method is significantly more accurate than other existing methods on evaluating the critical power at a particular node (i.e. the weak node of the n…
Voltage Collapse Proximity Assessment for Radial Distribution Networks
2005
The paper deals with voltage stability assessment in radial distribution networks. The voltage collapse proximity index already utilized in literature for power transmission systems is assumed. Based on the optimal impedance solution of a two-bus equivalent system, this index indicates how far the load nodes of the actual network are from their voltage collapse points, allowing the weak node and its maximum load power beyond which voltage collapse takes place to be identified. The proposed method differs from the other methods on the determination of the parameters which define the two-bus equivalent of the network, allowing to better identify the maximum loading point beyond which the volt…
An Optimization Package for Electrical Distribution Network Reconfiguration
2008
Hydropower Potential in Water Distribution Networks: Pressure Control by PATs
2014
Pressure control is one of the main techniques to control leakages in Water Distribution Networks (WDNs) and to prevent pipe damage, improving the delivery standards of a water supply systems. Pressure reducing stations (PRSs) equipped by either pressure reducing valves or motor driven regulating valves are commonly used to dissipate excess hydraulic head in WDNs. An integrated new technical solution with economic and system flexibility benefits is presented which replaces PRSs with pumps used as turbines (PATs). Optimal PAT performance is obtained by a Variable Operating Strategy (VOS), recently developed for the design of small hydropower plants on the basis of valve time operation, and n…
Quantifying residential PV feed-in power in low voltage grids based on satellite-derived irradiance data with application to power flow calculations
2016
AbstractA scheme using satellite-derived irradiance measurements to model the feed-in power of residential photovoltaic (PV) systems in a low voltage distribution grid is described. It is validated against smart meter measurements from a test site with 12 residential PV systems in the city of Ulm, Germany, during May 2013 to December 2014. The PV feed-in power is simulated in a 15-min time resolution based on irradiance data derived from Meteosat Second Generation satellite images by the physically based retrieval scheme Heliosat-4. The PV simulation is based on the nominal power and location of the PV systems as provided by the distribution system operator. Orientation angles are taken fro…