Suziana Ahmad

Statistical distributions of load profiling data

This paper present an approach to estimate the customer load confidence interval using statistical distribution model. Time series data of load profile in the utility of Malaysia was analyze and this data was fit with two statistical distribution models, namely the normal and log-normal distribution. Goodness of fit test was performed in the selection of best model. Result shows that the customer load consumption for each seven days can be model using both distributions. An estimated 90%, 95% and 99% customer load confidence interval was done via both distribution models.

Grid connected multilevel inverters for PV application

Due to the high electricity demand and the decreasing of fossil fuel sources, most of the countries around the world goes to renewable energy such as wind, tidal and photovoltaic (PV) for electricity generation. Among these, the study of PV as an alternative source for electricity generation has gain wide attention. One of the important aspects that should be considered in PV application is the use of grid connected multilevel inverter. This work focuses on three phase diode clamped multilevel inverter, capacitor clamped multilevel inverter and H-cascaded bridge multilevel inverter for connecting grid and PV application. These three types of multilevel inverters were simulated in Matlab-Simulink environment and a multicarrier pulse width modulation (PWM) was used for the control methods. The output waveforms of multilevel inverters are presented and comparison between these are given. The best topology for a grid connected multilevel inverter for PV application is recommended.

Simulation of three-phase cascaded H-bridge Multilevel Inverter with THIPWM

This paper presents the simulation of a Three Phase Five Level Cascaded H-bridge Multilevel Inverter. Third Harmonics Injection Pulse Width Modulation (THIPWM) technique was employed through s-function approach in SIMULINK environment to minimize the complexity of circuit design. The advantages of THIPWM are revealed in term of voltage and current THD reduction compared to Sinusoidal Pulse Width Modulation (SPWM) in three phase system. Simulation results reveal that voltage and current THD of THIPWM improved as much as 36% and 28% respectively compared to SPWMs.

Optimizing the flux and torque estimator of DTC in FPGA by using low-area square root calculator

This paper presents an alternative to improve the implementation of the torque and flux estimator for the Direct Torque Control (DTC) of induction motor drives in Field Programmable Gate Array (FPGA). The square root architecture is optimized to have low hardware resources utilization, by reducing the number of logic elements used, and subsequently contributing to reducing the power consumption. This is achieved by sharing the common hardware and eliminating parallel computation in the square root calculator, which is implemented by using the non-restoring algorithm. The proposed strategy was successfully implemented in ALTERA Cyclone II FPGA and the functionality of the system was validated via functional simulations.

Microgeneration of electrical energy using piezoelectric from car movement

The paper discuss on the method and process of microgeneration of potential energy power produce by piezoelectric on vehicles. This microgeneration method of harvesting from the vibration of the car itself will be used in order to generate power and the piezoelectric expected capable of produce low voltage output. The piezoelectric generator will be used as the main component in the microgeneration design. The study involved on investigation of vibration from different point within the car and choosing the best point. The piezoelectric device is then mounted near the selected vibration source from the vehicle. The outcomes will be contributed by vibrations in the vehicle, thus vibrates and displacement to the piezoelectric device to produce electricity.

Measurement of low frequency signal of power grid using Arduino

The range of the frequency to be measured by a measurement device depends on the purpose of performing the measurement. The frequency measurement device is built specifically according to its range while the price of the device is proportional to its functions. In this paper, a low frequency measurement device to monitor grid frequency is designed using Arduino technology. All aspects of the design from the software to hardware is explained. This device costs less than 100 US Dollar and it is capable to perform data logging for data analysis. The frequency range for the device is between 45 Hz to 60 Hz with 0.003 Hz resolution. This paper also discuss the standard commercial measurement device in power system and Arduino capabilities. The measurement data from the device is analyze for its accuracy and reliability.

Experimental Study on the Ground Resistance Reduction Based on Different Types of Grounding Rod

Grounding of electrical installation is primarily concerned with ensuring safety. The main purpose of grounding is to channel the fault current straightly to the earth. To produce a good grounding system, the value of earth resistance must be reduced as low as possible. Otherwise, current may flows through to those who touch the damage electrical equipment instead of flowing through grounding system. In this project, a 3 meter length of copper, galvanized iron and pure steel rod were installed in formatting of grounding system. The installation of the grounding rods was based on the fall of potential method. Both single rod testing and parallel rod testing were performed in this project. A comparison on grounding resistance value for copper rod, steel rod and galvanized iron rod was examined and the selection of the best grounding rod was determined from the experimental data. Result shows that different types of rod will produce different value of resistivity in which depend on installation technique and soil condition.

A case study on ground resistance based on copper electrode vs. galvanized iron electrode

Grounding of electrical installation is primarily concern with ensuring safety. The main purpose of grounding is to channel the fault current straightly to earth. To produce a good grounding system, the value of earth resistance must be reduce as low as possible. Otherwise, current may flow through to those who touch the damage electrical equipment instead of flowing through grounding system. In this project, a variety diameter of copper rod and galvanized iron rod were installed to build grounding system. The aim of this project is to find if there exists significance difference in the value of resistance when different diameter and different type of rod were used. Single rod testing and parallel rod testing were performed with fall of potential method to measure the value of earth resistance. Result shows that different types of rod with different diameter size produce different resistivity value which also depends on installation technique and soil condition.