The strategies of distribution network reconfiguration are applicable for minimizing power loss and saving electrical energy in the distribution system. Network reconfiguration is usually represented by constant load demand so ignoring the variability of load demand causes uncertainty and misleading results in the minimization of power loss. This paper consists of two parts: first, the reconfiguration was accomplished using an optimization framework based on constant load to find sets of optimal switches. The minimization of active power loss was taken as an objective function while bus voltage, branch current and system radiality were taken as system constraints. The study was applied to a 33-bus test distribution network, which is exceedingly used as test examples for solving reconfiguration problems. Second, lists of the configurations set obtained from the first part, as well as other different optimization methods proposed earlier under constant load demand were taken as test switches. Additionally, the network in the presence of distributed generators was taken to analyze the reconfiguration under an active network. Two types of load demands; the variable load and voltage-dependent load, are proposed to represent the practical load demands. This paper presents a new method for good analysis as it defines the effect of loading levels and loading patterns on a distribution system performance for passive and active networks. The proposed approach tries to find the actual power loss under different characteristics of loads. Therefore, the probable benefit of this approach is the contribution to providing more flexibility for electrical utilities in terms of distribution system operation, while also opening new prospects in the automation of smart distribution systems.

The combination of droop control and communication-based secondary control is eligible to maintain steady voltage and frequency at the point of common coupling (PCC) together with the property of power-sharing between distributed generators. However, the performance of this combination is threatened by slow dynamic and communication failure. In this context, an improved droop control is proposed to address the issue of slow dynamic and enhance the power-sharing accuracy in the autonomous microgrid. The droop coefficients are determined through a comprehensive analysis to assess the eigenvalues and plot the loci of the dominant poles. A robust secondary control is subsequently proposed to restore the voltage and frequency to their nominal values with a novel feature that ensures the performance continuity during communication failure. The key idea of the proposed secondary control relies on utilizing the predictive values of PCC voltage in the dq-rotating frame using two dynamic lookup tables during communication loss. The proposed control is evidenced by the simulation results in MATLAB environment.

Self-reconfiguration in electrical power grids is a significant tool for their planning and operation during both normal and abnormal conditions. The increasing in employment of Intelligent Electronic Devices (IEDs), as well as the rapid growth of the new communication technologies have increased the application of Feeder Automation (FA) in Distribution Networks (DNs). In a Smart Grid (SG), automation equipment, such as a Smart Breaker (SB), is used. Using either a wired or a wireless network or even a combination of both, communication between the Control Center (CC) and SBs can be made. Nowadays, wireless technology is widely used in the communication of DNs. This may cause several security vulnerabilities in the power system, such as remote attacks, with the goal of cutting off the electrical power provided to significant consumers. Therefore, to preserve the cybersecurity of the system, there is a need for a secure scheme. The available literature investments proposed a heavyweight level in security schemes, while the overhead was not considered. To overcome this drawback, this paper presents an efficient lightweight authentication mechanism with the necessary steps to ensure real-time automatic reconfiguration during a fault. As a first stage, authentication will be made between CC and SB, SB then sends the information about its status. To ensure the integrity of the authentication exchange, a hash function is used, while the symmetric algorithm is used to ensure privacy. The applicability of the suggested scheme has been proved by conducting security performance and analysis. The proposed scheme will be injected on ABB medium voltage breaker with the REF 542plus controller. Therefore, the probable benefit of the suggested scheme is the contribution to provide more flexibility for electrical utilities in terms of reducing the overall computational overhead and withstanding to various types of attacks, while also opening new prospects in FA of SGs.

Distribution companies (DSCOs) are trying to reduce the high real loss and manage the poor voltage profile, so power loss minimization and voltage profile improvement are the main and important tasks to be faced by electrical engineers in the distribution system (DS). To achieve this goal, distribution system reconfiguration (DSR) is one of the greatest keys and vital analysis to reduce power loss and enhance system voltage profile. In this paper, Modified particle swarm optimization (MPSO) is used for solving the DSR with the objective of minimizing real power loss in the presence of a regular of some constraints. To prove the applicability of the proposed method, MPSO has been applied on operated example the standard IEEE 33-bus system and the results compared with the other popular algorithms. It observed from the numerical results of the test that the real power loss is reduced by 31%, the average system voltage enhanced by 2% and 2.5% improves the minimum voltage.

The Loads in distribution systems are mostly inductive this coming from nature of system such as transformer and transmission lines, and most devices used in house is motors with reactive power consuming. For these reasons and others it will cases to reduce the voltage profiles and increases in power losses. The most distribution system is radially connected, the high voltage distribution system 33kv doesn't severe from low voltage problems; this is coming from nature of high voltage it is low voltage drop in transmission line and also the almost the substation 33kv supplied with capacitor banks. However The medium voltage distribution system 11kv, and low voltage distribution system 0.4kv are severe from low voltage problems at buses; this is coming from nature of high current in low voltage systems will cause high voltage drop in its wires, and these distribution systems are radial connection without capacitor banks. In this paper presented optimal capacitor placement and sizing to overcome to the low voltage problem and total power loss reduction of both these distribution systems. Simulation results are investigated on realistic in realistic radial feeder 11kv of alkaherat network 33kv which represent one of Karbala 33kv distribution system networks, feeds rural area with 20-bus load system of aburwaia region, after that apply to 0.4kv radial distribution system with 26-bus load system of alzwaia region one load of the feeder above. Results such as voltage support and power losses are analyzed. Different simulation results to optimal capacitor placement to voltage support, and minimizes power losses are analyzed by using Genetic Algorithms (GA) implemented in the ETAP software.

False data injection (FDI) attacks are a major security threat to smart grid (SG) communication systems. In FDI attacks, the attacker has the ability of modifying the measurements transmitted by smart grid entities such as smart meters, buses, etc. Many solutions have been proposed to mitigate FDI attacks in the SG. However, most of these solutions rely on centralized state estimation (SE), which is computationally expensive. To engulf this problem in FDI attack detection and to improve security of SGs, this paper proposes novel two-tier secure smart grid (T²S²G) architecture with distributed SE. In T²S²G, measurement collection and SE are involved in first tier while compromised meter detection is involved in second tier. Initially the overall SG system is divided into four sections by the weighted quad tree (WQT) method. Each section is provided with an aggregator, which is responsible to perform SE. Measurements from power grids are collected by remote terminal units (RTUs) and encrypted using a parallel enhanced elliptic curve cryptography (PEECC) algorithm. Then the measurements are transmitted to the corresponding aggregator. Upon collected measurements, aggregator estimates state using the amended particle swarm optimization (APSO) algorithm in a distributed manner. To verify authenticity of aggregators, each aggregator is authenticated by a logical schedule based authentication (LSA) scheme at the control server (CS). In the CS, fuzzy with a neural network (FNN) algorithm is employed for measurements classification. Our proposed T²S²G shows promising results in the following performance metrics: Estimation error, number of protected measurements, detection probability, successful detection rate, and detection delay.