A. Elmitwally

A Fuzzy-Multiagent Service Restoration Scheme for Distribution System With Distributed Generation

This paper proposes a new multiagent control system (MACS) for service restoration in distribution systems with integrated distributed generation (DG) units. First, the MACS detects and locates faults, then decides the optimal reconfiguration of the network for restoring de-energized loads, and finally regulates the nodes voltages. Unintentional islanding operation of DG units is avoided and different postfault response modes of DG unit are addressed in the MACS design. The MACS has a hybrid centralizeddecentralized structure where agents are arranged in two layers with different responsibilities and communication capabilities. Agents at load buses in the first layer can only communicate directly with its next neighbor load agents on the same feeder and to its feeder agent, whereas the higher level agents in the second layer can communicate directly with each other. This MACS structure reduces the possibilities of control system failures for a moderate communication network infrastructure. Full dynamic simulation model for evaluating the MACS is implemented.

Novel Multiagent-Based Scheme for Voltage Control Coordination in Smart Grids

AbstractIn this paper, a new multiagent-based voltage control scheme is proposed. The algorithm dynamically adapts the settings of control devices, such as the automatic voltage regulator of generators, transformer with under-load tap changer, and flexible alternating current transmission systems (FACTS), to optimize operational objectives. The objectives are controlling the generator excitation current, reducing transmission power loss, maintaining voltage stability, and improving voltage profile. The constraint is to keep the technical capability limits of system equipment and the transmission line power-flow limits. Furthermore, the effect of load model on voltage control dynamics is addressed. Peer-to-peer device communication is developed to facilitate information exchange among agents. The proposed scheme coordinates the operation of installed voltage control devices on both low voltage and high voltage levels. A simulation test model is implemented using a parallel computing arrangement for a 30-bu...

Algorithm for Transmission Loss Allocation in Market-Based Power Systems with Wind Generation

AbstractThis paper proposes a novel method for transmission loss allocation in restructured power systems. It is based on circuit laws and the orthogonal projection theory. In this method, the current flow in each branch is divided into two components. The first one is due to the power transfer from generators to loads. The second component is due to the voltage differences between generators’ buses. The later currents are called no-load or circulating currents. These two current components are computed by using the superposition principle. The contribution of each load and generator to power losses in each branch of the network is derived analytically. Hence, the share of each load or generator in the overall transmission network losses is estimated. Furthermore, the impact of bilateral and multilateral contracts is incorporated in the power loss allocation algorithm. The contribution of each contract to the total transmission system power loss is estimated accurately. The method also takes into account ...