In this paper the use of the proportional integral (PI) algorithm incorporated with the fuzzy logic technique has been proposed as advanced gain scheduling load frequency control (GLFC) in two-area power systems. The proposed controller comprises two-level control systems, such that it consists of a pure integral compensator which is connected in parallel with a PI controller. However, and based on load demand, the PI parameters are updated online by means of fuzzy logic rules. With this control technique it becomes possible to eliminate steady state errors as well as to maintain good transient responses. The task of keeping a stable and overall satisfactory mode of operation in interconnected electric power systems is the main goal of any control strategy. This should be guaranteed over a wide range of operating conditions and particularly in sudden and drastic load changes. Therefore, the suggested approach has been examined following abnormal changes in loading conditions to clarify its reliability. The report also investigates the performance of the pure integral (I) controller and GLFC in individual configurations to highlight the advantages of the offered algorithm over the standard ones. The criterion of integral square error (ISE) has been exploited in the performance assessment for the designed controllers. Several simulation scenarios have been conducted, using the MATLAB–Simulink package, to illustrate the proficiency of the developed technique.

The interconnection between diverse Distribution Generations (DGs) that utilize various technologies and complex structure of networks are the most characteristic of modern Distribution Networks (DN). The wide adoption of DGs considerably affects the power flow dynamics in the DN and consequently the fault characteristics. The excessive level of fault currents can pose risks of heat (high temperature) and pressure in accordance to Arc Flash (AF) incident energy in microgrids. This research studies the relationship between AF severity and the solving of coordination problem of Overcurrent Relays (OCRs) in DN, and introduces a novel equation that considers the AF qualities in solving the coordination problem for OCRs. In this study, a novel optimization problem, the AF severity with the optimal coordination of OCRs in DN is presented and the Water Cycle Optimization Method (WCOM) is employed to find the best combination of the OCR’s settings in the DN while considering the AF induced energy. The proposed optimization approach and the novel equation are evaluated with an IEC microgrid and compared with the conventional protection method and Particle Swarm Optimization (PSO) used in optimizing the coordination of OCR in the DN. The optimal settings of the OCR scheme are achieved and examined on the modified IEC microgrid benchmark system. In order to verify the result, an industrial simulation package (ETAP) and OCR (GE Multiin, model-750/760) was used in this work.

Voltage sags, as defined by the IEEE Standard, refer to sudden drops in voltage magnitude that last for a duration greater than 0.5 cycles of the power frequency but less than or equal to 1 minute. These events are considered significant in power quality issues. The change rate of voltage during a voltage sag can range from 0.1 to 0.9 per unit (p.u.) of nominal voltage, where 1 p.u. represents the nominal voltage level. Addressing the power quality (PQ) challenge is a critical component of ensuring the reliable and efficient operation of modern power systems. Advances in PQ monitoring and control technologies, power electronic devices, smart grid technologies, and PQ standards have all contributed significantly to improving PQ and enhancing the resilience and responsiveness of power systems. However, voltage sags are particularly challenging to resolve and may require a range of solutions. Voltage sags are a critical factor in PQ and can cause significant disruptions in the power system. As a result, mitigating voltage sags is a key area of focus in PQ improvement efforts. This paper presents an in-depth analysis of voltage sags in power grid, including their causes, characteristics, and harmful effects on electrical equipment and industrial processes. The authors highlight the significance of voltage sag mitigation techniques to reduce the economic losses and damage caused by these PQ issues. The paper provides an overview of existing mitigation techniques, including dynamic voltage restorer (DVR), distribution static synchronous compensator (D-STATCOM), and other custom solutions. Additionally, the paper discusses the economic impact of voltage sag on various industrial sectors, including the semiconductor and information industries. The authors emphasize the need for continued research and development of effective voltage sag mitigation techniques to enhance the stability and reliability of power grid and electrical systems. This paper is a valuable resource for researchers, engineers, and professionals in the field of power systems, providing insights into the causes and mitigation of voltage sags in the power grid.