Mohammad Lutfi Othman

PID controller adjustment for MA-LFC by using Imperialist Competitive Algorithm

In this paper a new evolutionary computing method based on Imperialist Competitive Algorithm (ICA) is used for tuning the elements of a PID controller which is applied in a Multi Area Load Frequency Control System (MA-LFC). If a large power imbalance is suddenly happened in a multi area power electric system, generation units and also consumer sides will be affected by the distortion in the energy balance between both two sides. This inequality is firstly handled by the kinetic energy of the system turning components, but, eventually, the frequency will change. Therefore, LFC is considered as one of the most challenging issues in power system control and operation. PID type controllers are conventional solutions for MA-LFC. The three parameters of the PID controllers have been adjusted traditionally. In this paper, a PID controller is applied for the MA-LFC problem and then its parts are modified by using ICA method. To validate the application of the technique, a multi area network with some uncertainties is provided. Finally the results of the ICAPID controller are compared with the ones of GA optimized controllers. The simulation results show the success and the validity of the ICA-PID controller in compare with the GA - PID controller.

Rough-Set-based timing characteristic analyses of distance protective relay

Nowadays protection engineers are suffering from very complex implementations of protection system analysis due to massive quantities of inconsistent data, let alone coming from diverse intelligent electronic devices (IEDs). Thus, a novel Rough-Set-based data mining strategy has been formulated to resolve the inconsistency in a distance protective relays decision system (i.e. a transformed relay event report) in such a way that the relays timing characteristics hidden in its decision algorithm of protection operations have been successfully discovered. Using Rough Set Theory, the inherent uncertainty and vagueness in the relay event report have been resolved using the concepts of discernibility, elementary sets and set approximations. The timing characteristics that have been successfully discovered are in relation to the relay trip assertion activity, impedance element activation, fault characteristics, circuit breaker operation and its overall decision system approximation.

Efficient parallel routing algorithms in optical multistage interconnection network

The crosstalk problem is introduced by an optical multistage interconnection network, which is caused by coupling two signals within a switching element. To avoid this crosstalk, a time domain approach is used, which is to partition the set of the connections into several subsets such that the connections in each subset can be established simultaneously in the network without crosstalk. Since we want to partition the messages to be sent to the network into several groups, we have to use a window method that is used for finding the conflicts among all the messages to be sent. In this paper, we proposed two parallel window method algorithms called unbalanced parallel window method (UPWM) and balanced parallel window method (BPWM) algorithms. The UPMW algorithm reduced the execution time approximately 79%, whereas the BPMW algorithm reduced 85% of the time compared to the sequential algorithm if we use seven processors.

Role of FACTS devices in improving penetration of renewable energy

In recent years, the renewable or green energy has been a major focus globally. Moreover, this energy can be like solar and wind which have been increasingly implemented worldwide. However, the adoption of the green energy is still low due to high technological costs and the associated power system issues. The effectiveness of Flexible Alternating Current Transmission System (FACTS) devices in problems that are related to the power systems has been tremendous. Although, there are still relatively limited works on incorporating FACTS devices into green energy plants. The progress of the FACTS application in renewable energy plants has been reviewed in this work. In addition, it has been discovered that FACTS plays an equally effective role in improving the power system quality of green energy plants especially in wind and solar plants. The rate of penetration of green energy could be accelerated if applications of FACTS devices in renewable energy plants were to be more widely adopted.

Ant Colony Optimization Technique in Optimal Capacitor Placement and Sizing Problem in Unbalanced Electrical Distribution System

The optimal capacitor placement problem involves determination on the type, number, location and size of capacitors to be placed in a distribution system for the attainment of energy efficiency. The main objectives of the capacitors placement and sizing are to reduce total line loss and energy consumption while satisfying the operational constraints. This paper presents the optimal capacitor placement and sizing problems solved by using the Ant Colony Optimization (ACO) technique with the integrated of circuitry unbalanced electrical distribution modeled in SIMULINK® MATLAB® software. The proposed technique was tested on a modified IEEE 13-bus unbalanced radial distribution system and the results revealed that the proposed technique has the merit in achieving optimal solution for addressing the problems.

Coordination of overcurrent relays protection systems for wind power plants

Wind farms are one of the most indispensable types of sustainable energies which are progressively engaged in smart grids with tenacity of electrical power generation predominantly as a distribution generation system. Thus, rigorous protection of wind power plants is an immensely momentous aspect in electrical power protection engineering which must be contemplated thoroughly during designing the wind plants to afford a proper protection for power components in case of fault occurrence. The most commodious and common protection apparatus are overcurrent relays which are responsible for protecting power systems from impending faults. In order to employ a prosperous and proper protection for wind power plants, these relays must be set precisely and well coordinated with each other to clear the faults at the system in the shortest possible time. This paper indicates how the coordination of overcurrent relays can be effectively attained for wind power plants in order to protect the power constituents during fault incidence. Through this research Matlab/Simulink as a powerful simulation software have been applied to model a wind farm and achieve precise setting for coordination of overcurrent relays.

Small signal stability assessment and control of power systems

A method for assessment and control of small signal stability (SSS) has been proposed in this paper. As the angle of rotor represents the stability of the system, the proposed method tries to assess the instability and its solutions by using comparison instead of time consuming conventional method. The idea divides power networks into different areas. The system has sub-controllers and main controller with different authorities which will results in fast and reliable prediction and control of SSS. Artificial intelligence could be used as a tool that would give the ability of learning to the system which gives the system the opportunity to response fast and accurate in future problems.

WLAN oriented optimization of process bus in IEC 61850-based substation communication network

The communication standard IEC 61850 which is defined for information exchange in smart grids, has been increasingly used for Substation Automation Systems (SAS). Current mainstream communication technologies such as switched Ethernet and TCP/IP have been adopted for the communications networking. However, with the growing amount of IEDs in one collision domain, a risk of violation of transmission time requirement increases. This raises a concern for optimization of IEC 61850 based substation communication network. The industrial wireless LAN technologies are gaining interest power utility sector, especially for less critical smart distribution network applications. This paper proposes methods of software simulation for performance evaluation of communications network in power substations. This method enables to test the performance of process bus only using Sampled Value (SV) and obtains a maximum number of WLAN IEDs in one collision domain subject to various conditions.

Artificial Neural Network Application in Optimal Coordination of Directional Overcurrent Protective Relays in Electrical Mesh Distribution Network

Directional Overcurrent relays (DOCR) applications in meshed distribution networks (MDN), eliminate short circuit fault current due to the topographical nature of the system. Effective and reliable coordination’s between primary and secondary relay pairs ensures effective coordination achievement. Otherwise, the risk of safety of lives and installations may be compromised alongside with system instability. This paper proposes an Artificial Neural Network (ANN) approach of optimizing the system operation response time of all DOCR within the network to address miscoordination problem due to wrong response time among adjacent DOCRs to the same fault. A modelled series of DOCRs in a simulated IEEE 8-bus test system in DigSilent Power Factory with extracted data from three phase short circuit fault analysis adapted in training a custom ANN. Hence, an improved optimized time is produced from the network output to eliminate miscoordination among the DOCRs.

Modeling and simulation of the industrial numerical distance relay aimed at knowledge discovery in resident event reporting

In the motivation of tapping the strong potential of computational intelligence in discovering knowledge of protective relay operations using data mining, modeling and simulation of an actual industrial numerical distance relay and its recording facility are a vital requisite. This is justified by the practicality and necessity of divulging the decision algorithm hidden in the recorded relay event report using computational intelligence-based data mining. Thus, this paper studies the detailed modeling and simulation of an industrial AREVA MiCOM P441 distance relay, accommodated together with its own simulated event report recording facility. The idea is to provide the flexibility of allowing the simulated event report to have sufficiently significant depth and breadth for data mining purposes. The modeled relay has operated correctly and discriminatively in deciding circuit breaker pole(s) to be tripped in stipulated assertion times as per the Malaysian licensee’s requirements for various faults and protected zones along a transmission line. It has subsequently been validated successfully by the performance of the real field AREVA MiCOM P441 distance relay belonging to the Malaysian licensee. With the successful modeling and simulation of the AREVA MiCOM P441 distance relay and its recording facility, such subsequent works as data extraction and preparation, computational intelligence-based data mining for relay decision algorithm discovery and finally a relay analysis expert system development can certainly be executed. These subsequent applications are briefly explored as a demonstration of the benefit offered after the successful modeling of the relay.