Radial Low Voltage Distribution Research Articles

Smart Charging of Multiple EVs in Smart Grid Radial Low Voltage Distribution Networks

Abstract The harsh emissions constraints have pushed the Automotive industry to introduce Electric Vehicles (EV). Since the beginning of this millennia the numbers of EVs have increased from thousands to millions nowadays. The impact of EVs charging, over the Electrical networks has been studied in many publications, and everybody reached the same conclusion: if EV’s charging is not managed, the energy industry will suffer; increased investments, new energy production facilities will lead to increased energy prices. The concept of managing the EV’s charging process is connected to Smart Grid concept, and many publications are stating that a single centralized entity should regulate the chargingprocess. As such, in this paper a similar centralized EV charging control algorithm in low voltage distribution networks (LVDN) is proposed. The proposed algorithm, is regulating the EV charging power, while considering the LVDN network constraints. Specifically, the voltage constraints are taken into account, because the voltage levels within the network are a power supply quality indicator.

DSTATCOM-Fuel Cell System on Radial Low-voltage Distribution Network for Mitigating Voltage Rise Caused by High Penetration of Photovoltaic Systems

DSTATCOM-Fuel Cell System on Radial Low-voltage Distribution Network for Mitigating Voltage Rise Caused by High Penetration of Photovoltaic Systems

Optimal Allocation of Energy Storage Systems for Voltage Control in LV Distribution Networks

This paper addresses the problem of finding the optimal configuration (number, locations, and sizes) of energy storage systems (ESSs) in a radial low voltage distribution network with the aim of preventing over- and undervoltages. A heuristic strategy based on voltage sensitivity analysis is proposed to select the most effective locations in the network where to install a given number of ESSs, while circumventing the combinatorial nature of the problem. For fixed ESS locations, the multi-period optimal power flow framework is adopted to formulate the sizing problem, for whose solution convex relaxations based on semidefinite programming are exploited. Uncertainties in the storage sizing decision problem due to stochastic generation and demand, are accounted for carrying out the optimal sizing over different realizations of the demand and generation profiles, and then taking a worst-case approach to select the ESS sizes. The final choice of the most suitable ESS configuration is done by minimizing a total cost, which takes into account the number of storage devices, their total installed capacity and average network losses. The proposed algorithm is extensively tested on 200 randomly generated radial networks, and successfully applied to a real Italian low voltage network and a modified version of the IEEE 34-bus test feeder.

City distribution by solid low-voltage networks

A few years ago, the most economical form of distribution system for use in cities was considered to be obtained by the use of duplicate high-voltage transformer-feeders in combination with radial low-voltage distribution. Since that time the solid low-voltage network has been widely adopted in other countries, particularly in America. With this arrangement the supply route to any consumer is at least duplicated all the way, which results, it is claimed, in improved voltage regulation and reliability of service. On the other hand the parallel operation of the transformers introduces unfamiliar problems such as increased fault duty in the l.v. network and the reverse flow of power from the l.v. network into transformer or h.v. cable faults. This latter has hitherto been dealt with by sensitive reverse-power protection on the transformers, but it now appears that all the requirements can be met merely by fuse protection. With this modification the scheme is worthy of serious consideration for application in this country, and it is thought that with certain precautions as to fault duty in areas of dense loading many existing city distribution systems could advantageously be converted to solid working. The scheme is, however, most attractive where a rather light section of l.v. cable is laid and is proving inadequate with orthodox methods.