Imran Sutan Chairul

AC breakdown voltage of natural ester mixed with Iron Oxide for oil-immersed power transformer application

Nowadays, nanoscale materials are increasingly popular in academic and industrial research. It is expected that the combination of nanoscale materials with other material can contribute more benefits. The use of nanoscale materials often require their dispersion in variety of liquids, to enable them to become part of the liquid product, also known as nanofluids. For example, one of the applications is the nanoparticles dispersed with transformer oil in oil-immersed transformer application. Traditionally, mineral oil is used as dielectric liquid and cooling medium in power transformer. In this paper, dielectric strength of ester oil when mixed with nanoparticles is investigated. For that purpose, AC breakdown voltage test is compliance with ASTM D1816 standard is performed. Statistical analysis and high dimension visualization have been done to analyse and compare the result between fresh ester oil taken from tank and the similar ester oil that mixed with nanoparticles. The results suggest that ester oil mixed with nanoparticles of 0.02 % by volume performs well compared to other samples.

Development of Test Vessel for Gas Insulation Breakdown Test

Efficiency, reliability, high power quality and continuous operation are important aspects in electric vehicle attraction system. Therefore, quick fault detection, isolation and enhanced fault-tolerant control for open-switches faults in inverter driving systems become more and more required in this filed. However, fault detection and localization algorithms have been known to have many performance limitations due to speed variations such as wrong decision making of fault occurrence. Those weaknesses are investigated and solved in this paper using currents magnitudes fault indices, current direct component fault indices and a decision system. A simulation model and experimental setup are utilized to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed fault detection approach.The inverter with critical loads should be able to provide critical loads with a stable and seamless voltage during control mode change as well as clearing time. The indirect current control has been proposed for providing stable voltage with critical load during clearing time and seamless control mode transfer of inverters. However, the islanding detection is difficult since with the indirect current control the magnitude and frequency of voltage do not change when the islanding occurs. The conventional anti-islanding method based on the magnitude and frequency of voltage variation cannot apply to the indirect current control. This paper proposes an islanding detection method for the indirect current control. The proposed islanding detection method can detect the islanding using reactive power perturbation and observation when the frequency and magnitude of voltage don’t vary during clearing time. In order to verify the proposed anti-islanding method, the experimental results of a 600W three-phase inverter are provided.

A Preliminary Study on Optimizing the In-Lab Reclamation Process Parameters of Used Transformer Oils Using the Taguchi Method

With the rapid growth of communications via the Internet, the need for an effective firewall system which has not badly affect the overall network performances has been increased. In this paper, a Field Programmable Gate Array (FPGA) -based firewall system with high performance has been implemented using Network FPGA (NetFPGA) with Xilinx Kintex-7 XC7K325T FPGA. Based on NetFPGA reference router project, a NetFPGA-based firewall system was implemented. The hardware module performs rule matching operation using content addressable memory (CAM) for higher speed data processing. To evaluate system performance, throughput, latency, and memory utilization were measured for different cases using different tools, also the number of rules that an incoming packet is subjected to was varied to get more readings using both software and hardware features. The results showed that the designed firewall system provides better performance than traditional firewalls. System throughput was doubled times of the one with Linux-Iptables firewalls.

Dielectric breakdown performance of mineral oil and palm fatty acid ester oil mixture blended using ultrasonic homogenizer

Mineral oil is a petroleum-based oil which is nonrenewable and is running out in the future. It is also non-biodegradable, thus, it can be harmful to the environment when there is oil spillage. Therefore, this work is conducted with an intention to reduce the usage of petroleum-based oil by mixing it with natural ester oil. This is achieved by mixing the mineral oil (MO) and palm fatty acid ester (PFAE) oil with a ratio of 20:80 and vice-versa by using homogenizer machine. Through the homogenizing process, each mixing sample is vibrated for 20 minutes to complete the miscibility of both insulating liquids. AC breakdown voltage test compliance with ASTM D1816 standard is conducted on the oil mixtures to investigate their dielectric breakdown performance. Comparison is made with the virgin MO and PFAE that used as benchmark. The results suggest that the optimal breakdown voltage was obtained by blending an 80% MO with 20% PFAE to improve the dielectric breakdown performance of mineral oil alone.

Breakdown and partial discharge performance of Palm Fatty Acid Ester (PFAE) oil-based Fe 3 O 4 nanofluids

In high voltage transformer application, mineral oil is typically used as insulation liquids because of its excellence in dielectric strength and cooling medium. However, despite the benefit of mineral oils, these oils are derived from petroleum, which is a non-renewable and non-sustainable source. In this study, palm fatty acids ester (PFAE) is used as insulation oil to investigate the performance of dielectric strength when mixed with Fe3O4 (also known as Iron Oxide) nanoparticles. The AC breakdown voltage and partial discharge inception voltage (PDIV) were measured to evaluate the performance of samples. In this paper, the PFAE oil mixed with Fe3O4 nanoparticles show improvement in AC breakdown voltage and PDIV test which is 42 % and 13 %, respectively.

Transformer Fault Classification from Polarization Current Measurement Results by Using Statistical Technique

In general, the presence of moisture and other impurities inside the insulator or oil can cause the breakdown of the power transformer. Polarization and Depolarization Current (PDC) is one of the technique to assess the condition of insulation oil in power transformer and can be applied in many electrical apparatus such as power cables and on load tap changer as well as to estimate conductive and moisture content of the insulation. Basically, it is a technique that is based on time domain measurement and has been used since 1990. For this research, the PDC data will be analyzed using graphical method and statistical technique to classify the transformer faults into a proper range. Lastly, it will be validated with the results from previous research. The output of the research work revealed that in term of the sequence, the results obtain in both graphical technique and the statistical technique is identical with the results presented in previous research. Hence, the range of the faults started with partial discharge, followed by arcing and lastly is the overheating.

Formation and Effect of Moisture Contents to Kraft Paper’s Life of In-Service Power Distribution Transformer

Examples of solid and liquid electrical insulations for power transformer are mineral oil and cellulose based paper. As transformers performed their function to step-up or step-down voltage level, its’ insulations will be degraded. Paper insulation is considered the most critical component in a transformer insulation system because it is not easily replaced if compared to oil where it is easily reconditioned in-order to remove water and contaminants. Studies show that temperature, moisture contents and oxygen contributed to paper insulation degradation. Moisture and furanic compound were produced from these deterioration processes. This paper is focused on the formation and effect of moisture to Kraft paper’s life. Levels of moisture contents were obtained from in-service power distribution transformers. These data then is used to assess the Kraft paper’s life by means of Weibull plot. This study shows that level of moisture contents can be used to assess the life of Kraft paper insulation.

Automated Calculation of Thermodynamic Potential Applied for Proton Exchange Membrane (PEM) Fuel Cell

Energy sources are the utility main important aspect in our daily basic life. However, their cost of operation, installation or maintenance is continuously growing to be highly expensive and to this, the solution is by encouraging the usages of recently famous renewable energy, Proton Exchange Membrane (PEM) Fuel Cell. However, this PEM Fuel Cell is not widespread and still new in Malaysia as well as the research is still in the initial stage. Therefore, the purpose of this research is to design the Automated Calculation of Thermodynamic Potential Applied for PEM Fuel Cell. In this project, two different steps will take place. First, the implementation of block parameters of PEM Fuel Cell via MATLAB simulink software (*.mdl) has been used to calculate the hydrogen pressure against Thermodynamic Potential (Enernst) value and temperature against Enernst. In order to ensure that the calculation is accurate, these two different values will be compared with the theoretical calculations. Next, the development of Graphical User Interface (GUI) by using Microsoft Visual Studio is implemented. This GUI is prepared in order to create the application of Automated Calculation of Thermodynamic Potential Applied for PEM Fuel Cell. As a result, the new developed application system is expected to automatically calculate the nominal efficiency and the thermodynamic potential value of PEM Fuel Cell.

Comparative Study of Worldwide Standards for Interpreting Frequency Response Analysis (FRA) Results of Distribution Transformers

Distribution transformer in Malaysian electricity network is categorized as major element on delivering electricity throughout the nation. Advanced diagnostic tools are used to monitor any technical problem of transformer to sustain its capability in the long run. One type of it which is currently being used in worldwide is Frequency Response Analysis (FRA). The reliability from this method is proven worldwide in diagnosing transformer condition especially a mechanical movement. FRA technique is done by comparing the response result in transformer initial condition to its current condition. The interpretation of transformer condition from the response is based on frequency sub-bands. Each frequency sub-bands are indicating any movement parts of transformer and electrical faults. Currently, there are three worldwide standards established for interpreting the FRA results but both of them are different in frequency sub-bands range. Up to now, there are no research papers comparing the fault detection capabilities from frequency sub-bands range for both standards. In this paper, comparative study is done to visualize and interpret the capabilities from three standards (IEEE Std C57.149 2012, DL/T911-2004 and Cigre WG A2/26); by focus on the frequency sub-bands range.

Study of magnetic fields produced by transmission line tower using finite element method (FEM)

Transmission line is a medium to transmit electric energy from one place to another for long distances. For instance, the aim is to reduce losses. Typically, in Malaysia the overhead transmission line was used because cost and maintenance can be handling easily. Despite, the transmission line also produced high strength of electric and magnetic field under the tower. Therefore, the tendency of magnetic field effected to the human and environment has to be identified wisely. However the real measurement under transmission line tower may give high risk. Therefore the best approach is to carry out the information by performing simulation study. In this project, Finite Element Method (FEM) via ANSYS Maxwell software was carried out. The transmission line modeling is focused on 132kV and 275kV specifications. Magnetic field analysis under the transmission tower is carrying out in this research work. Finally, it is a successful work in modeling the transmission line by validating the result with the actual on-site measurement especially on 132kV transmission line.