The effects of harmonic contamination on distribution transformer losses and temperature rise have become an increasing concern. This problem is caused by the widespread presence of non-linear loads and their ever-increasing proportion in the power system networks. The paper focuses on the particular effect of voltage harmonics on oil-filled distribution transformers losses. Laboratory experiments including short circuit and open circuit tests were conducted on two distribution transformers of different age. The results reveal significant increase in losses. Equations are proposed for correcting the calculation of the total transformer loss.

This paper presents an implementation to enhance the protection scheme of smart distribution grid. In order to improve the existing protection scheme used in Malaysia that is "Current Differential Protection", to a new level of protection that used the idea of combining the "Current Differential Protection" and "Fast Current Protection". This project was developed to increase the efficiency of protection, decrease any unnecessary cost regarding the protection maintenance or equipment used, and space used for installing a particular protection scheme. Besides that, neither "Current Differential Protection" nor "Fast Current Protection" has their own advantages and disadvantages for their perspective protection scheme. The results were proven by simulating the design using PSCAD software, which the new design, combined both theories of "Current Differential Protection" and "Fast Current Protection". The building cost for the new design can be reduced in installation or maintenance.

The effect of harmonic contamination on distribution transformer losses has become an increasing concern over the last decade. This problem is caused by the widespread presence of non-linear loads and their ever-increasing proportion in the power system networks. In addition, many transformers have been in operation for years and service-aging also exacerbates the power losses. This paper presents a comparative study between two oil-filled distribution transformers of different age. Short circuit and open circuit tests were conducted under various voltage harmonic excitations to determine transformer electrical parameters. Results reveal sensitivity of the core load loss on voltage harmonics. Also observed is higher load loss in the aged transformer under harmonic pollution.

This project present analysis and implementation of cross blocking feature as the solution for overcoming the mal-operation of the transformer differential relay in sympathetic inrush phenomena. The sympathetic inrush phenomena will occur to the transformers that connected in parallel. The inrush current will flow to the transformer that is already energized when energizing the second transformer on the power system. It will effect a voltage drop and this voltage drop caused the saturation to the already transformer in the negative direction. These phenomena caused the mal-operation of the relay that the main point of this project is to overcome it. The results obtained after designing 100MVA, 33/ 11kV three phase transformer by using PSCAD/ EMTDC simulation. As results, cross blocking method will operate as a block tripping and this method is useful to eliminate mal-operations that occur during the energization of the transformer due of the failure of harmonic restraint function in transformer differential relays. These analyses solve the problem of sympathetic inrush current phenomena.

Vegetable oil (VO) have been constantly researched as an alternative to the conventional mineral oil (MO) in the application of transformer insulation liquid. VO is deemed as a suitable replacement for MO as they are a renewable source, cheaper in price, and have a high thermal conductivity, high flashpoint, and high breakdown voltage value. In addition, the trending interest in nanofluids has made it possible to further improved the insulating properties of VOs. This paper reports the experimental results of thermal conductivity test of Palm oil-based nanofluids and Palm fatty acid ester (PFAE)-based nanofluids. The nanoparticles used in this work is Zinc Oxide (ZnO) <50nm nano powder and the nanofluid (NF) samples are varied by low, medium and high concentrations. The test was conducted at 9 different temperatures from 25°C to 65°C with 5°C gap. The result shows that a low and medium concentration nanofluid has an improvement in thermal conductivity value, up to 42.6% and 59.5% respectively for palm oil-based nanofluid. Meanwhile, the high concentration palm oil-based nanofluid has lower enhancement in thermal conductivity value at certain temperatures. As for PFAE-based nanofluids, the thermal conductivity value has improved by up to 27% and 14.4% for medium and high concentration respectively. Nanofluids with medium concentration of ZnO, has the highest enhancement in insulating and cooling properties for both palm oil and PFAE-based nanofluids. This observation is supported by the kinematic viscosity value of the mentioned nanofluid.

This project is to present the transient recovery voltage on circuit breaker in power system network. The transient recovery voltage is a characteristic in power system and will found just only microsecond in the power system network. The objective of this project is to simulate and analysis the transient recovery voltage on circuit breaker. It is to investigate the transient recovery voltage before and after the circuit breaker interrupts and also the transient recovery voltage under the fault. The method used in this project is by simulating the circuit using the PSCAD software. This software will simulate the circuit model and collect some data to give more understanding about transient recovery voltage. This project will continue by analyzing the result based on the data collected. The simulation results are same with the expected results and thus, it show that the simulation results are correct and pre theoretical. In conclusion, the transient recovery voltage affects the breaking capacity of the circuit breaker operation and also affects the power system network operation.