Mohd Ruddin Ab Ghani

Active suspension control: performance comparison using proportional integral sliding mode and linear quadratic regulator methods

The purpose of this paper is to compare the performance of the active suspension system using two different control strategies. The first strategy utilized the proportional integral sliding mode control scheme and the second one using the linear quadratic regulator method. A quarter-car model is used in the study and the performance of the controller is compared to the linear quadratic regulator and with the existing passive suspension system. A simulation study is performed to prove the effectiveness and robustness of the control approach.

Proportional-Integral sliding mode tracking controller with application to a robot manipulator

This paper presents the development of a Proportional-Integral sliding mode controller to control a class of uncertain systems. It is assumed that the plant to be controlled can be represented by its nominal and bounded parametric uncertainties. A robust sliding mode controller is newly derived so that the actual trajectory tracks the desired trajectory as closely as possible despite the non-linearities and input couplings present in the system. The Proportional-Integral sliding mode is chosen to ensure the stability of overall dynamics during the entire period i.e. the reaching phase and the sliding phase. The controller is applied to the control of a two-link planar robot manipulator.

Economical optimization of conductor selection in planning radial distribution networks

A new computer algorithm and program is presented for selection of optimal conductor type and size for each feeder segment. An acceptable voltage profile is maintained along the entire feeder of the network while obtaining an objective of minimizing the total cost, which consists of capital investment and cost of feeder losses, etc. Node numbering scheme and node connection sequence selection have been proposed to determine the node current and voltage drop for each individual node and termination end of each feeder branches and power loss of each segment of the feeder. If the conductor size available fail to satisfy the user defined constraints the designer can rerun the program after making the relevant changes to the inventory database. The proposed method has been successfully applied in the solution of an example of distribution network that is presented.

Demand-side management

Power utilities worldwide are under mounting pressure to ensure that power system development is environmentally friendly. Demand-side management (DSM) programme is viewed as the least-cost energy resource when both environmental costs and welfare needs are taken into account. It is a utility financed programme for total energy savings approach to reducing peak and base loads. It introduces a new element into the planning framework by allowing for a deliberate intervention by the power utility in the market place to influence customer use of electricity in order to alter the system load shape. It encompasses the planning, evaluation, implementation and monitoring of programmes selected from a wide range of technology and marketing alternatives. The success of each alternative depends on the marketing activities to promote customer participation. This paper outlines projects being undertaken as part of plans to develop and implement appropriate DSM programmes in Peninsular Malaysia. Although various DSM programmes are widely implemented in many developed countries, their adaptation to Malaysia must first be evaluated to ensure their techno-economic viability and customer acceptance for ultimate success. The development of this and related projects is outlined.<<ETX>>

Performance Comparison for Parabolic Dish Concentrating Solar Power in High Level DNI Locations with George Town, Malaysia

Parabolic Dish (PD) Concentrating Solar Power (CSP) generation has appeared as one of Renewable Energy (RE) that is efficient and trustworthy. As technology moves into commercialization, it is necessary to study the performance of PD system at various locations. Current literature on PD especially for tropical environment such as Malaysia and locations with Direct Normal Irradiance (DNI) lower than 1500 kWh/m2/year is still scarce and scattered. Most of the studies are focusing on the performance at location with DNI higher than 2100 kWh/m2/year. Therefore, this paper presents the performance of PD in tropical environment of Malaysia and four other locations such as; Thailand, Korea, Australia and United States of America (USA). System Advisor Model (SAM) was used to analyze the performance of PD for the selection countries. The simulation result shows that the annual energy production for George Town in Malaysia is 21,845 kWh, and shows areas of high DNI have high power output such as Pheonix, USA 184,189kWh; Canberra, Australia 121,536 kWh; Bangkok, Thailand is 48,736 kWh and Inch’on, Korea 45,450 kWh.

Customized Fault Management System for Low Voltage (LV) Distribution Automation System

1. Introduction Supply disruption such as overloading will cause interruptions of electricity supply to customers. The technicians have to manually locate the fault point and this tedious work may last for extended periods of time. The other reasons are the lack of use of efficient tools for operational planning and advanced methodology for quick detection of fault, isolation of the faulty section and service restoration. Currently, fault detection, isolation and service restoration takes a long time causing the interruption of supply for a longer duration.

Stirling Engine Technology for Parabolic Dish-Stirling System Based on Concentrating Solar Power (CSP)

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.

Optimizing hydrothermal coordination scheduling for large scale power

The Tenaga Nasional Berhad (TNB) system comprises 53 thermal units and 10 hydro plants of 37 generators (80 units). Lagrangian relaxation (LR) technique, Datzig-Wolf linear programming, sub-gradient method (SGM) and branch and bound (B&B) have been used to relax the LR multipliers for demand and reserve requirements, and decompose the problem into unit-wise initially and thermal and hydro sub-problems finally. The multipliers are then updated at the lower bound level by SGM. B&B along with some heuristics to get a feasible schedule in the hydro-thermal coordination system. The heuristics used are based on programming with C language code that simplifies on/off statuses of units for commitment (UC) and scheduling and economic load dispatch (ELD). The TNB costs have been reduced as shown in the results.

A Low Cost Wireless Data Acquisition System for Distribution Automation System

This paper analyzed the design and development of a 16F877A microcontroller-based wireless data acquisition system. Besides, it also discussed the possibility of different existing methodologies to be linked to field data acquisition from distribution automation systems. Various existing data transmission techniques were studied, especially for wireless systems such as satellite, radio, GSM and paging. The hardware and software implementations were included. The system was used for reading, storing and analyzing data which were obtained from DAS. The wireless communications were based on the GSM network. The laboratory results were compared with the simulation results to determine final conclusion.

Remote Terminal Unit Developed for Distribution Automation System (DAS) Using MPLAB Software

Remote Terminal Unit (RTU) is a standalone data acquisition and control unit which monitors and controls an equipment at a remote location from the central station that utilizes Distribution Automation System (DAS). The RTU acquires information such as measured values, signal, meter readings and it transmits command or instruction, sets points, controls variables and monitors function time. In the present Distribution Automation System (DAS), the distribution field of automation allows the utilities to implement a flexible control of distribution system to enhance efficiency, reliability, and quality of electric service. The implementation of distribution automation system is highlighted based on two factors; benefit and area of distribution automation system implementation. The hardware design uses PIC16F877A microcontroller to control all the functions of RTU. The types of fault detected are undervoltage and overcurrent. The design consists of MPLAB software development using C programming and hardware assembly. RTU is also designed to communicate with the Supervisory Control and Data Acquisition (SCADA) system and resulting in RTU’s ability to detect undervoltage and overcurrent fault.