El-Nobi A. Ibrahim

An Important Study of Transverse Faults on Twelve-Phase Power Systems

Recently there has been growing interest in the technology of high-phase order power transmission, in place of conventional three-phase power transmission, for increasing the power transmission capability of overhead electric power transmission rights-of-way. One of the most important items in applying high-phase order transmission systems (12-phase systems) is the study of the faults that may appear in these systems. This paper starts with a historical review of the Four Three-Phase Symmetrical Components Technique, which was proposed for analyzing the faults that could occur on 12-phase power systems. Then a detailed study of transverse short-circuit faults that could occur on such systems is given in terms of this technique.

Hybrid PD-Fuzzy controller for high performance linear switched reluctance motor under different operating conditions

This paper aims to design a hybrid PD-Fuzzy position controller for high performance linear switched reluctance motor (LSRM). The mathematical model of LSRM is developed and simulated by Matlab/Simulink package. The essential feature of the proposed hybrid PD-Fuzzy controller is to use a PD controller only for coarse position error, then for fine position error LSRM position control is done using a fuzzy logic controller only. New force distribution function (FDF) is proposed to overcome the problems of electromagnetic force ripples due to LSRM nonlinear magnetic characteristics. Through a hysteresis controller, asymmetric three phase power converters can be controlled to drive the LSRM. Simulation results prove the effectiveness of the proposed hybrid PD-Fuzzy controller in position setpoint precise tracking under different loading disturbances and different position setpoint.

Supervisory controller for power management of AC/DC microgrid

This paper proposes a hybrid AC/DC micro grid to reduce the processes of multiple conversions in an individual AC or DC micro-grid. The hybrid grid consists of both AC and DC networks connected together by a bidirectional AC/DC converter. Wind generator, AC loads, and utility are connected to the AC bus whereas PV system and DC loads are tied to the DC bus. The coordination control algorithms of supervisor controller are proposed for smooth power transfer between AC and DC links and for stable system operation under various generation and load conditions. In this paper, a flexible supervisor controller is developed for a hybrid AC/DC micro-grid, where the power flow in the micro-grid is supervised based on demanded power with maximum utilization of renewable resources. A small hybrid micro-grid has been modeled and simulated using the Simulink in the MATLAB. The simulation results show that the system can maintain stable under load variations.

PI Multi-Objective Genetic for LFC Based Different Wind Penetration

Future energy descent systems will be expected to be controlled by the using of renewable power sources of which wind energy is one of the favorable sources. This paper treats with the implantation of genetic algorithms for making the parameters needed for PID applied to interconnected thermal and hydraulic power systems at best use and most effective. Two-areas of hydraulic and thermal power systems with wind connected parallel to each one are considered to exemplify the effective parameter investigation. First hydraulic and thermal are connected with tie line with the wind connected parallel to hydraulic or thermal, and then disturbance was made at thermal power plant, then to hydraulic power plant. Simulations are performed aided by the integrated Simulink/Matlab environment taking into consideration the genetic optimization process. Multiple integral representations variables with different cost functions were considered in the search for the effective AGC parameters. The outcomes established by this paper shows the impact of the genetic algorithms for LFC about multiple areas connected power systems based on different wind power using in the tuning of such a process.

Optimal operation and battery management in a grid-connected microgrid

Recently, Smart grid is one the important concepts that improve the energy future. This paper proposes an economic optimization technique for battery management to reduce the operating cost of a gr...

Energy management strategy for AC/DC microgrid

This paper proposes a grid connected AC/DC microgrid to reduce the processes of multiple conversions in an individual AC or DC microgrid. The hybrid grid consists of both AC and DC networks connected by a bidirectional AC/DC converter. Wind generator, AC loads and utility are connected to the AC bus whereas PV, energy storage system (ESS) and DC loads are tied to the DC bus. The coordination control algorithms of supervisor controller are proposed for smooth power management between AC and DC links and for stable system operation under various generation and load conditions. In this paper, a flexible supervisor controller is developed for a grid connected AC/DC microgrid, where the power flow in the microgrid is supervised based on demanded power with maximum utilisation of renewable resources and ESS. So, the objective of this paper is to use supervisory controller to control the transferred power from AC bus to DC bus and vice versa and control the charging/discharging power of the ESS to reduce the purchased power from the grid or to increase the sold power to the grid with respect to the load demand. The microgrid has been modelled and simulated using MATLAB Simulink. The simulation results show that the system can maintain stable under load variations.

Enhanced MG with optimum operational cost of pumping water distribution systems

The sector of water pumping is one of the greatest consumers of electricity. Integrating microgrids and renewable energy sources facilitates stainable energy future. This paper proposes an optimal operation of energy management system in a microgrid with water pumping. The microgrid includes PV, wind turbine, and energy storage system (ESS). The proposed method determines the optimal hour-by-hour scheduling for the microgrid system while it meets the required demand and includes a water pumping station. Genetic algorithm (GA) was applied to solve the problem with an objective of total operational cost minimization. The method was applied to a typical microgrid system with different parallel-connected pump configurations. The results indicate high potential savings for the total operating cost.

Voltage regulation of stand-alone variable speed wind energy system

This paper presents simple control of a variable speed stand-alone wind turbine with a permanent magnet synchronous generator (PMSG) to get constant voltage. The system consists of a wind turbine, PMSG, un-controlled rectifier and voltage source inverter using PI control. The parameters of PI control are calculated by using try and error method. The system is modified by using a switch mode rectifier and a voltage source inverter between the PMSG and a three phase loads. The loads that used are resistive, inductive and capacitive loads. By adjusting the parameters of a buck converter, we get a good result. Results have been done using PSIM/SIMULINK.

Analysis and control of HVDC transmission power system

This paper presents a design of converter controllers and filters of Line Commutated Converter High voltage direct current (LCC-HVDC) power transmission system to increase loadability and reliability of long power transmission. Also the proposed tuned PI controllers for HVDC Converters are verified in sense of HVDC transmission system performance and reliability. The studied system performances are compared with HVAC transmission systems in terms of power transfer quantity and reliability for a wide range of transmission distances and operating conditions. The Power Quality of HVDC transmission system is studied with Filters and proposed PI controllers. The two transmission systems (HVDC & HVAC) are simulated using MATLAB SIMULINK software package. With the control strategy, the HVDC system can provide a useful and economical way to transmit electric power over the long distance compared with HVAC system.