Boon Ching Kok

Application of Analytic Hierarchy Process (AHP) in load shedding scheme for electrical power system

This paper proposes a methodology for the load shedding scheme for electrical power system by using the Analytic Hierarchy Process (AHP). The process AHP is a structured technique for dealing with complex decisions. In this paper, an effective method that can solve a multiple criteria and multiple objective decision-making problems was introduced to the load shedding scheme in electrical power system problem in order to gain a scientific and objective maintenance scheduling. Firstly an AHP model is built up on the base of analyzing correlative factors with an example given to indicate how the AHP is applied.

Linear Feedback Controller for D-Statcom in DPG Fault Application

This paper presents the application of linear feedback controller on distribution static synchronous compensator (D-STATCOM) for mitigating double phase to ground (DPG) fault at the distribution system. The pole placement technique is applied by shifting the existing poles to the new poles locations for fast response compare to the conventional controller. This type of inverter control is very useful in D-STATCOM application which controls the inverter to inject the unbalanced current or voltage or both for mitigating the fault condition that occurs at the distribution system. The controller will give respond to the lines that are affected by the fault and restore the system to its normal conditions. The simulation and design of the controller is done using MATLAB software with Power Blockset Toolbox and SIMULINK

A unique load shedding application in a large pulp mill electrical system

Nowadays advanced technology in producing powerful equipments or devices in engineering sector not only help engineer from various fields such as mills and construction to rectify problems instantly but in more relevant and reliable ways. For example, microprocessor protection relay in the market, which is a type of protection relay that can be linked up with profibus, modbus and etc to centralize control system for supervision, control, monitoring and data collection or storage purposes to enable end users to monitor and observe the system easily. This type of centralized integration concept is the future development trend, which will benefit end users.

Modelling and design analyses of a piezoelectric cymbal transducer (PCT) structure for energy harvesting application

The piezoelectric cymbal transducer (PCT) is auspiciously identified as the best design for piezoelectric energy harvesting, particularly in high stress conditions. It is designed to harvest the ambient mechanical stress and vibration that ubiquitously exist in our environment into electrical energy. In this paper, a PCT structure is examined for its energy harvesting capabilities in both, mechanical and electrical environment using COMSOL FEA (Finite Element Analysis) simulation software. The PCT design structure comprises of piezoelectric disk slotted in between two dome-shaped metal end caps and slip rings. The shallow cavity depth allows the mechanical force to magnify the distributed circumferential force on the piezoelectric disk. A load resistor is introduced to the finite element method (FEM) via PSPICE netlist as to calculate the harvested power of the PCT. It has been discovered that the different metal end caps materials, the dimension of the piezoelectric disk and end caps with various electrical resistive load had significant corresponding effects on the power generation of the PCT. A total generated power of 0.46mW has been obtained from a PCT dimension of 32mm diameter wide along with a 0.3 thickness end cap under a 50N force across 3M load resistance.

LOAD SHEDDING SCHEME IN LARGE PULP MILL BY USING ANALYTIC HIERARCHY PROCESS

Pulp mill is one of the heavy industries that consumes large amount of electricity in its production. In particular, the breakdown of the generator would cause other generators to be overloaded. Thus, load shedding scheme is the best way in handling such condition. Selected load will be shed under this scheme in order to protect the generators from being damaged. In the meantime, the subsequence loads will be shed until the generators are sufficient to provide the power to other loads. In order to determine the sequences of load shedding scheme, analytic hierarchy process (AHP) is introduced. Analytic Hierarchy Process is one of the multi‐criteria decision making methods. By using this method, the priority of the load can be determined. This paper presents the theory of the alternative methods to choose the load priority in load shedding scheme for a large pulp mill.

Special HVDC controls for TNB/EGAT HVDC interconnection system

The actual controls system of TNB/EGAT HVDC interconnection system is implemented in a high-speed graphically programmable digital control system. This paper describes the features and operations of the controllers by giving a brief description of the pole control functional environment that is employed in the TNB/EGAT HVDC interconnection system. This paper then explains the custom model development of the special controls for the power order setting functions such as power run-up and run-back control, dual frequency modulation, frequency limit and transient current order control of the actual HVDC system. The purpose of these controllers is to improve the power stability of the AC-DC system. The dynamic performance tests of the developed models give a good response in terms of power stability improvement.

Wind Prediction in Malaysia

The wind speed prediction in Kudat, Malaysia had been done by using Mycielski-1 approach and K-mean clustering statistical method. There is some improvement in obtaining the random number of Mycielski-1. Besides, the comparison of K-means clustering with the optimal number of K is presented in this paper. The wind prediction is important to study a favorable site’s wind potential. The prediction is based on 3 years history data provided by Meteorology Department of Malaysia and 1 year data as the reference to check the accuracy of both algorithms. The basic concept of Mycielski-1 algorithm is to predict the next value by looking to history data. Meanwhile, the K-means clustering can group the values with similar mean into the same group, and the prediction can be done by getting the probability of occurrence. The result shows the prediction of Mycielski-1 algorithm and K-means clustering are promising. The wind speed is predicted in order to obtain the mean power for energy planning.

Comparison studies between generic simulation model and site recording of TNB-EGAT HVDC link

This paper presents the comparison of the four operation and performance tests that are conducted on the generic simulation model of the TNB-EGAT interconnection system and compared the results with the site recordings data. The generic simulation model of the HVDC system has been done piece by piece in the electromagnetic transient program and the functionality of each piece of the model has also been confirmed with field data. The system response tests are power step response, current step response, DC voltage step response and also the extinction angle step response. Reasonable and satisfactory results have been obtained from the generic simulation model compared to the site recording commissioning tests.

Data acquisition system for Piezoelectric Cymbal Transducer energy harvesting

This paper presents a portable and low cost data acquisition (DAQ) system for Piezoelectric Cymbal Transducer (PCT) energy harvesting system. Conventional DAQ system is operates based on bulky and expensive personal computer (PC) which is inflexible to be used in PCT energy harvesting system. The proposed system consists of self-assembly PCT, electrical energy harvesting circuit and ARMmbed microcontroller. Direct mechanical compression force via hand press is induced onto the PCT in DAQ sampling works. The efficiency of the proposed DAQ system is verified through Digilent electronics explorer board (EE board). The measured sampling data is available in two modes, which are on-site monitoring using graphic liquid crystal display (GLCD) and online monitoring via WebSocket server. The test results have demonstrated high accuracy of the proposed DAQ system with maximum error of 0.4% and 1.05% in voltage and energy measurements, respectively. The proposed microcontroller based DAQ system fulfils industrial and consumer demand in term of cost effective, flexible and high efficiency design.

Greenhouse gas forecast in Barton Water injection reinstatement project

Discovery the most effectual resolution to control the greenhouse gases (GHG) emissions is one of the most essential long-term challenges sophisticated by the society. Efficacious frameworks for CO2 management will definitely advantageous on reducing CO2 emission while promoting the technologies and investments to enhance energy efficiencies and decrease the CO2 intensities. Therefore, the GHG management from oil and gas facilities is still a priority. Continuous various efforts such as reduction in flaring, waste-water treatment before discharging to the environment, and oil spill prevention have encouraged the waste management to follow the model of prevention, such as reuse, recycle, recovery, etc. Those countermeasure techniques are widely implemented by oil and gas industries towards environmental performance at the work site and its surrounding area. This paper is mainly focused on the Barton field located at the off coast of Sabah, Malaysia. Due to the advancement at Barton field, overabundance of GHG emission is one of the main issues. Therefore, the main intension of this paper is to provide the forecasted GHG emissions for Barton Water Injection Reinstatement Project (BTWI). The predicted GHG emissions will be very handy to provide an insight for the future improvement on water injection system in BTWI project.