Nuriziani Hussin

Palm Oil as the Cooling Liquid in Single Phase Transformer for Better Efficiency

The important purpose of mineral oil in transformer is to be insulant and it is role of being a coolant. Petroleum based oil is commonly used because it has a good dielectric strength and cooling performance. However, the application of mineral oil brings negative impact to the environment such as oil spills, leakage, explosion and soon petroleum based oil will be running out for future generation used. Thus, vegetable oil is chosen as an alternative to replace mineral oil for transformer insulation liquid. Formerly, most of Malaysian researches were focusing on the properties of the vegetable oils rather than investigate the effect on the transformer performances after the vegetable oils are applied. Hence, this paper focuses on the performance of the transformer before and after vegetable oils are applied. For this paper, refined palm oil is used as insulation liquid for a single-phase step down transformer which use the 220 V supply and 50 Hz frequency. Transformer is connected to 110V induction motor as load and has been test in two conditions, dry and after palm oil is applied. Comparison is made from both results and clearly shown a good improvement when palm oil is used as insulation oil.

Viscosity Reduction of Palm Oil via Ultrasonic Radiation

Insulation is one of the most important parts in the power transformer. Palm oil impregnated paper is investigated to replace the mineral oil impregnated paper due to the high viscosity of palm oil compared to the viscosity of the mineral oil. This paper discussed on ultrasonic radiation technique that was used to reduce the viscosity of the vegetable oil (palm oil) for transformer insulation application. The ultrasonic equipment produces 500W heating power, 240W ultrasonic power at a fixed frequency of 40 kHz. Ultrasonic radiation was applied on oil samples at 30 °C, 50 °C and 75 °C by using the sonicator water bath for several periods of time. The results show up to 42.6 % reduction from the original viscosity of palm oil and proved to have a long term effect on the viscosity of palm oil. The cavitation bubbles that occur in the sample during radiation is one of the mechanism in viscosity reduction.

Damping Improvement of Power System Oscillations by Using Optimal Coordinated Design between PSS and SVC-Based Stabilizer

The large expansion of electrical power systems usually results in problem of low frequency oscillations. Therefore, the conventional Power System Stabilizers (PSSs) used to solve this problem cannot provide an adequate damping of low frequency oscillations. Flexible AC Transmission System (FACTS) damping controllers are available for providing suitable damping for these oscillations. This paper, presents the simultaneous coordinated design of the multiple damping controllers between PSS and SVC-based stabilizer in a single machine infinite bus power system. The coordinated design problem of multiple damping controllers is formulated as an optimization problem. Particle swarm optimization algorithm is applied in order to search optimal controlling parameters by maximizing the objective function based on the eigenvalue. The simulation results for a wide range of operation condition show that the coordinated design able to provide better damping and stability performance.

Study on Palm Oil and Treated Waste Vegetable Oil Impregnated Paper

Oil impregnated insulation paper plays an important role in a transformer as it insulates the windings from high voltage and current. Other than the type of paper used, the properties of oil such as viscosity, relative permittivity and dielectric loss play a major factor that contributes to the quality of the insulation paper. This paper discussed the sonication and esterification process on palm oil and treated waste vegetable oil and its’ effects on the performance of oil impregnated paper. Basically through these processes, viscosity of oils will reduce. However, the resultant permittivity and dielectric loss as well as its’ breakdown strength are rarely reported. Experiments were set to process (sonicates and esterify) the natural oils prior to the paper impregnation process. Results show that esterification is more effective than sonication process in reducing insulation oil viscosity, relative permittivity and dissipation factors as well as increasing the breakdown voltage of the oil impregnated paper. Palm oil methyl ester (POME) could serve as an excellent insulation oil which is very suitable as transformer oil as well as the impregnation medium for paper insulation.

Experimental study on vegetable oils properties for power transformer

One of the most important equipment in electrical power system is transformer. Most of transformers are using oil as the cooling medium and commonly use petroleum based oil. The reason of choosing petroleum based oil as transformer oil because it has a good dielectric strength and cooling performance. However, the usage of mineral oil has affected the environment as its non-biodegradability property and non-renewable resource. Therefore, renewable resource like vegetable oil is chosen as an alternative to replace mineral oil for transformer insulation liquid. In this paper, palm oil, coconut oil and virgin coconut oil are tested in a single-phase step down transformer that use 220 V supply and 50 Hz frequency with a load 110 V induction motor. Then, those vegetable oils are taken to undergo oil measurement experiments such breakdown voltage test, moisture content test and viscosity test. Before and after application of oils into power transformer are compared and it shows that virgin coconut oil has the highest breakdown voltage, lowest moisture content and also lowest viscosity, which are very good. It can be said that virgin coconut oil is better than palm oil and coconut oil.

Efficiency Improvement of Single Phase Transformer Using Virgin Coconut Oil

The application of mineral oil in transformer is prominently act as and insulator and a coolant liquid. More often, petroleum based oil is used because most its elements are good to act as insulator such as excellent heat transfer and low in viscosity. Anyhow, the usage of mineral oil in transformer is possibly hazardous to the environment considering that it is poor biodegradable liquid where when a spill or leakage happens, it could pollute the environment surroundings. Moreover, it is known as a non-renewable energy sources, the world will be out of it someday near future. For this reason, a new option of transformer insulation liquid is studied. Vegetable oil is a fully biodegradable insulating liquid and for this paper, coconut oil is used as the insulator. In this paper, it concentrates on the performance of the transformer before and after virgin coconut oil is applied in a single-phase step down transformer that use the 220 V supply and 50 Hz frequency. Transformer is connected to 110V induction motor as load and has been test in two conditions, dry and after virgin coconut oil is applied. Comparison is made from both results and clearly shown a good improvement when virgin coconut oil is used as insulation oil.

Harmonic Current Effect on Three Phase 100kVA Transformer Losses under Static Load and Dynamic Load

This paper describes the harmonic current effect under static and dynamic load on 3 phase 100kVA transformer model. The methodology that used to measure a harmonic current is using power analyzer with different excitation. The experiment is conducted by changing input voltage with different flux density. A waveform can be obtained by using the data collected. 3rd order of harmonic gives a high impact to the complex waveform. At 0.6 Tesla, 50 Hz, the 3rd order of harmonic current under static load and dynamic load is 0.00196A and 0.26746A respectively. Therefore, both static and dynamic load were give an effect to harmonic current effect on transformer. This is because when the transformer connected to the load, more current and voltage induced in order to energize the load. Moreover, the loads itself have their own harmonic effect because of the functional mechanism.

Differentiation of Harmonic Current Effect at T-Joint and Corner Joint on Three Phase 100kVA Transformer Losses

This paper describes the harmonic current effect at T-joint and corner joint on 3 phase 100kVA transformer model. The methodology that used to measure a harmonic current is using search coil connected to oscilloscope. The experiment is conducted by changing input voltage with different flux density. From the results obtained, the 3rd order harmonic current shows the highest for both T – joint and corner joint. The highest harmonic occurred at T – joint. For in plane, the harmonic current is 0.237A at corner joint and 0.389A at T - joint. At normal condition, the harmonic current were 0.250A and 0.769A at corner joint and T – joint respectively. This happened because of more energy required for transferring the flux to the left and right of the core. The corner joint of harmonic is less since the flux direction is 90° thus smaller amount of energy is required for the movement.

Comparative Studies of Vegetable Oils as Transformer Insulating Oil

In general, transformer is one of the most important equipment in the power system, the reliability of a transformer is commonly determined by its insulation condition. The insulation liquid that has been used for decades is petroleum based mineral oil which has a very good cooling performance. However, it is insidious to the environment. Hence, vegetable oils such as coconut oil and palm oil are used as the alternative to replace the mineral oil. In this paper, it presents the comparative studies from previous experiments on dielectric strength, moisture content, viscosity, pour point and flash point of both vegetable oils.

Effect Different Limb of Transformer Core Assemble on Performance

This paper described the performance of transformer affected by different limb assembling. The experiment that used to investigate core is no-load, short circuit and load test to find the core loss, copper loss, flux leakage at corner joint and limb and total harmonic distortion of the flux at flux density range from 0.2 T to 1.6 T, 50 Hz. From the result of this investigation shows the core loss of transformer assembled with 2 limbs is 18.45% and 32.21% better than the transformer assembled with 3 and 5 limbs respectively at a flux density of 1.6T, 50 Hz. To increase the numbers of core limb assemble will reduce the efficiency of transformer.