I. Daut

Clear sky global solar irradiance on tilt angles of photovoltaic module in Perlis, Northern Malaysia

The performance of a photovoltaic (PV) is highly influenced by its orientation and its tilt angle with the horizontal, due to the fact that both the orientation and tilt angle change the amount of solar radiation reaching the surface of the PV module. This paper presents a calculation of tilt angle and global solar irradiance on PV module in Perlis, Northern Malaysia. A mathematic method is used to calculate tilt angles and clear sky global solar irradiance, which depend on latitude and day number. The clear sky global solar irradiance consists of beam, diffuse and reflected solar irradiance. The tilt angles and clear sky global solar irradiance change every day in a year and analyzed. The monthly average beam, diffuse, reflected and clear sky global solar irradiance are shown and analyzed in this paper. The tilt angles of PV module in Perlis, Northern Malaysia are −17.16° to 29.74°. The positive, zero and negative tilt angles indicate that the PV module is facing south, on horizontal surface and north, respectively. The monthly average beam solar irradiance give a highest value compared with the diffuse and reflected solar irradiance. The average monthly beam solar irradiance of a year is, 968.36 W/m2, diffuse and reflected solar irradiance are 88.22 W/m2, and 4.70 W/m2, respectively. Based on global solar irradiance of a year, Perlis has a big global solar irradiance potential, its average is 1019 W/m2. These data show that the clear sky global solar irradiance can be used for certain application, especially in PV power generation.

State space averaging technique of power converter with digital PID controller

This paper describes a digital Proportional-IntegralDerivative (PID) controller technique applied to the DC-DC buck converter. The converter is modelled using a state space averaging technique. Due to the non-linear of the power converter, the PID controller is designed to simplify the compensation of the DC-DC converter. The control algorithm is implemented in Digital Signal Processor (DSP) TMS320F2812. The steady state and dynamic response performances of the controller are demonstrated. Experimental results are provided to demonstrate the effectiveness of the design.

Rotation-Elevation of Sun Tracking Mode to Gain High Concentration Solar Energy

Power conversion from solar thermal energy to electrical energy is still very cost-intensive. Serious effort has to be given in the development of the concentrator or heliostat structure expenditure which contributing the most expensive component in a central receiver solar power plant. With current development to find alternatives and lower down the capital, an alternative scheme of sun tracking has been developed and feasibility tested. The proposed rotation-elevation mode of sun tracking has significantly benefits use in high temperature and high concentration solar energy applications. Instead of offering stationary location for large and heavy solar powered Stirling engine application, the process of optical alignment works are reasonably easier and less time consuming. This paper at first will highlight and elaborate its concept and follow with some experimental results.

Implementation of DSP based SPWM for single phase inverter

This paper presents theoretical and experimental aspects related to the implementation of a Digital Signal Processor (DSP) based Sinusoidal Pulse Width Modulation (SPWM) for single phase inverter. Two sinusoidal reference signals complement to each other are compared with a carrier signal to generate PWM signals for the switches. A digital SPWM algorithm is implemented in DSP TMS320F2812 using SIMULINK model constructed from blocks of the C2000 Embedded target Library. The efficiency of the inverter is high and its offers less total harmonic distortion. The proposed system is verified through simulation and is implemented in a prototype, and the experimental results are compared.

Potential of wind and solar energy using Weibull and hargreaves method analysis

This paper presents an analysis of wind speed characteristics and solar radiation received in Perlis, Northern of Peninsular Malaysia. The characteristic of wind and solar is recorded per hour for a month using Davis Vantage Pro2 Weather Station. Recorded data is analyze using Weibull distribution function and Hargreaves method for wind and solar respectively. The analysis through Davis Vantage Pro2 Weather Station is then used to compare wind and solar data collected from Chuping station, Malaysian Meteorological Department. From overall of this work, the authors found that the potential of wind and solar energy through out Weibull and Hargreaves method is successfully analyzes.

Sensitivity of low voltage consumer equipment to voltage sags

Voltage sag is an issue that is becoming increasingly important to electricity consumers at all level of usage. These result from with increasing use of electronic equipment in several sectors for the reason to improve energy efficiency and performance. Customers included in low voltage environments mostly are sectors: Commercial, Residential and Light industrial. In these sectors many found equipments such as television, microwave ovens, personal computers, printer, lighting, heating ventilation air conditioners, motor contactor etc. Using with high efficiency fluorescent lighting with electronic ballast, single phase switch mode power supplies for computers, contactor for protecting motor from suddenly restarting when the voltage is recovered. These equipments are characterized as highly susceptible to voltage sags. Voltage sags are most frequent among various types of power quality disturbance faced by many consumers. Source of voltage sags are generally caused by short circuit faults associated with equipment failures on the supplying power system. Voltage sags normally do not cause equipment damage, but it can easily disrupt the operation sensitive equipment. Effects produced by voltage sags are various generally depending on its characteristics and equipment. The magnitude and duration of the sags are commonly used to evaluate sensitivity of equipment. The other characteristic such as point on wave of voltage sag initiation is significance influence to be considered. This paper presents voltage sag tolerance levels curves of three equipments sensitive to sags namely; personal computers, contactors and lightings. A Schaffner “Profline2100” has used to generate voltage sags and testing to get sensitivity of the equipment.

Comparison on losses and flux distribution between two 3-phase distribution transformers 1000KVA assembled with air gap and without air gap of transformer core lamination

This paper describes the result of an investigation on the effect of air gap of core lamination in two 3-phase distribution transformers 1000 kVA. The investigation involves the variation of power loss, building factor, the third harmonic distortion and flux leakages. The power loss and flux distribution have been measured using no load test in two types of model of setting of core built from the same size and type of M5 (CGO) grades material of laminations. And the loss of the transformer core without air gap of layer joint of core lamination is 2.75% better than the loss of the transformer core with air gap of layer joint of core lamination at 1.7 T, 50 Hz. The flux leakage at the corner joint in the core without air gap of layer joint of lamination is lower than that in the transformer core with air gap of layer joint of lamination, over the whole flux density range. The third harmonic distortion of flux is smaller in the transformer core without air gap of layer joint of lamination and larger in the transformer core with air gap of layer joint of core lamination. Using the type without air gap of layer joint of lamination in transformer core is more efficient than the other types of transformer core lamination.

A 5-level multilevel inverter using LM350 voltage regulator IC

This paper presents a 5-level multilevel inverter for low power applications that not exceeding 30W using the common LM350 voltage regulator IC. A microcontroller with appropriate program is used to control on the biasing resistance of the IC and H-bridge inverter in order to produce the quasi-sinewave looking waveform. Analysis of the output results are shown with levels of percentage harmonics. This new concept of multilevel inverter can be used for further study due to its simplicity and low in cost.

Design of Quantum Dot Based LASER with Ultra-Low Threshold Current Density

Reduction in threshold current density is the major challenge in the field of semiconductor laser design. The threshold current density can be minimized by introducing low dimensional material system with narrow band gap. InN has a narrow band gap of 0.7 eV and quantum dot provides three dimensional confinement factor. In this paper, we propose then InN quantum dot as the active layer material that will serve both the purpose of narrow band gap and three dimensional confinement. The simulation results show that the current density reduces drastically with the cavity length.

Parameter determination of 0.5 hp induction motor based on load factor test-a case study

The load can influence the efficiency of the induction motor. Even if the load has higher or less load factor, it can reduce the efficiency of an induction motor by several percentage. By knowing this, it is important that an induction motor be loaded with an appropriate or load factor of 100%. In this paper, the experiment is conducted to prove that efficiency decreases when the 0.5 hp induction motors is interfaced under low load factor condition and in this case a 65% load factor. The induction motor is interfaced with a DC generator and a variable resistance as load. In order to determined the efficiency and the mechanical output power of the induction motor, the voltage of the induction motor is varied from 0–415 volt and the appropriate data is taken. This is then analysis and several calculation formulas are used to determine the motors parameters. After that the losses are segregated and from this we can compare the efficiency values in which it shows low efficiency of 66.62% based on output/input method and 66.34% by using the losses formula. This proofs that at low load factor the efficiency of the induction motor reduces.