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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.

Power transformers studies have shown that the main cause of power transformers failures is the On Load Tap Changer (OLTC). OLTC failure occurs due to the insulation degradation and contacts failure inside it. Other than that, contacts wear influences the OLTC performance and this phenomenon has not been deeply investigated. The worn contacts will cause hotspots in the OLTC tank and cause the insulating oil to degrade faster. Consequently, this will lead to the damage of complete transformer unit. Thus, the research work that has been carried out applied three different stages related to the diagnosis of OLTC. Firstly, fault detection of power transformer's OLTC is done mainly based on the results of the DGA interpretation by using the latest Duval Triangle method. Then, the results that obtained from latest Duval Triangle method are compared with the results carried out from Dynamic Current Measurement (DCM). Finally, research validation through visual inspection is applied to validate the results obtained from both DGA and DCM.

Distribution transformer is the key element in the electricity transmission throughout the nation. Hence, serious attention for the transformer condition monitoring is a crucial. With an occurrence of short-circuit in the power system, the transformer active parts such as core and winding will experience a mechanical movement created by the electromagnetic forces. There are various types of transformer condition monitoring measurement in market, but the monitoring of the mechanical movement in transformer is still lacking. Therefore, Sweep Frequency Response Analysis (SFRA) has been introduced to assess any mechanical movement especially of the transformer's core and winding. The frequency response of the transformer provides mechanical information of core and winding conditions. The SFRA measurement results were validated using the actual transformer untanking process.

Generally, the insulation degradation and contacts failure happened inside the On Load Tap Changer (OLTC). Besides, the OLTC performance can be dropped due to contact wear. Hence., the worn contact creates hotspots inside OLTC tank and affects the insulating oil. Due to this phenomenon, the insulating oil will degrade faster. Consequently, the whole unit of the transformer will be affected as well. Therefore, it is important to find new ways to detect the contacts wear inside the OLTC as it impacts the insulation oil and the age of the transformer. Thus, this paper demonstrates the application of Duval Triangle method during the diagnosis of OLTC to provide any significant indication related to the breakdown of OLTC. Besides, this paper introduced the advanced technique, Dynamic Winding Resistance Measurement (DWRM) to figure out the types and locations of faults occurred inside the OLTC. Finally, visual inspections will be carried out to validate the both results obtained from DGA and DWRM respectively. The analysis in this paper revealed that the findings from Duval Triangle method were similar to the outcomes carried out by DWRM.

The main purpose of this paper is to design an optimal electrical power generation system using Renewable Energy in Pulau Perhentian Besar Island in Malaysia. This island was chosen in this study particularly because of the lack of record on the energy power generation assessment of islands in peninsular Malaysia. One of the important aspects of this study, is to reduce energy consumption with the applications of some new methods (Passive House, HVAC, Natural ventilation) to design entire buildings (residential, services) in Pulau Perhentian Besar Island and as a result, cost of electrical power generation will be optimal and accomplishable. Moreover, based on the potential renewable energy in this island, this paper attempts to propose electrical power generation with the use of solar and wind energy to cover overall energy requirements in Pulau Perhentian Besar Island. In this investigation, for the estimation of design cost, HOMMER soft is used to analyze the required solar panels, batteries, converters and etc, which dependent on the amount of solar radiation. The aim was to illustrate, that renewable energy can be an appropriate alternative instead fuel and is capable of supplying the required energy.