PetGrab- linker services – a conceptual business model

the objective of this paper is to propose and introduce to people an apps that will help to link between clinic and pet owners. petGrab aims is to help user which are the pet owners to get their pets treatments in order to make sure their pets healthy. In this paper also, we propose the Business Model Canvas (BMC), strategy canvas, environmental map and value proposition design (VPD). This is a conceptual solution that been proposed. Other than that, this paper also has proposed enhanced BM

The electrical behaviour of polymer insulator under different weather conditions

This paper presents the behavior of 33kV polymer insulator under nominal voltage and impulse by means of lightning activities. The electrical performance of the insulator is translated to electric field under uniform weather conditions which comprises of air humidity and contamination. ANSYS Maxwell modeling software is used to simulate the structure of the polymer insulator based on the real existing insulator’s dimension. The trend of electric field increase is discussed in detail

Lightning impulse strength of 275 kV and 132 kV tower with composite crossarm

Severe lightning overvoltage is regarded to the multiple flashovers on the overhead lines. Therefore, it signifies the needs of having a robust insulation system, especially to those which highly susceptible to lightning strikes. In order to minimize the impact of lightning, it is necessary to evaluate lightning performance of the tower and its components before implementing any proposed design. Therefore, in this work, a feasibility study was done on proposed 275 kV and 132 kV transmission tower with composite crossarm installed. In order to assess the insulation strength of the tower against the lightning activities, lightning caused events i.e. backflashover and shielding failure were applied onto the tower models by using FEM based software. The CFO of the tower insulation were calculated based on the design provided, whereby it was complementary verified by the voltage and electric field profiles of the simulation. For each case, none had shown a voltage magnitude higher than the voltage supposed to possibly cause 50% chance of flashover

Influence of air humidity and contamination on electrical field of polymer insulator

This paper presented the simulation results on electric field performances of medium voltage polymer type insulator while its mechanical conditions were reviewed. The purpose of this study is to investigate the electric field behaviour of 33kV polymer type insulator under different weather conditions by mean humidity and pollution. In addition, outdoor service environments of the insulator were reviewed as they are realized to have worldwide issues on degradation of polymeric material. Using 2D simulation, the electric field was found higher nearer to the end fittings whereby increased up to 38.89% under humidity and pollution. Also, the electric field behaviour along the cross section of weathersheds increased up to 661.59% under humidity and 547.30% under pollution. Meanwhile the weak points along the insulator were identified according to the magnitude of electric field strength. This research also verified the sharp edges and the thickness of the material of insulator as one of the factors that affect electric field strength

On the voltage and electric field distribution along polymer insulator

In this paper, the outdoor polymer insulator was studied and the related electrical and mechanical conditions were reviewed. Moreover, different outdoor insulators were technically compared together. Furthermore, voltage distribution along a real polymer 33kV insulator was studied and the results were discussed accordingly. On the other hand, the voltage and electric field profiles at longitudinal and cross sections under different voltage levels were considered and discussed

Considering the effects of a cross-arm on a contaminated polymer insulator at different angles

This paper considers the effects of a cross-arm on a contaminated polymer insulator at different angles (90°, 60° and 45°) with negative and positive impulses. An experiment was conducted using a 10 kV polymer insulator that was contaminated with 4 % salt (a mixture of distilled water and sodium chloride). From the experiment, the behaviour of the voltage breakdown and leakage current of the contaminated insulator positioned at different angles from the cross-arm was evaluated under different impulse polarities. The results show that the values of the breakdown voltage and leakage current decrease with angle when using the 90° angle as a reference. The reason for this study into the effects of the cross-arm on a contaminated polymer insulator is because in the real case, when the insulators are installed on an angle tower, the forces or tensions due to the weather conditions (especially under strong winds) and from the distribution lines themselves will force the installed insulators to be tilted from its original 90° angle position

Considering the effects of a RTV coating to improve electrical insulation against lightning

One of the factors that cause power outages on distribution lines is being struck by lightning. Cloud to ground lightning often affects overhead distribution lines and can occur with negative or positive polarities. It can affect the performance of insulators and cause power line failure. Furthermore, outdoor polymer insulators are exposed to extreme weathering and pollution, which can cause chemical changes in the material properties and further leads to material degradation. These can cause a reduction in the insulator withstand capabilities and may lead to flashover. This paper investigates the effects of a RTV (room temperature vulcanisation) coating on a 10 kV polymer insulator in order to improve the electrical insulation performance against a lightning impulse under clean and polluted conditions. The up and down test method was used to evaluate the withstand voltage capabilities of an RTV coated polymer insulator. For reference, the withstand voltage for a basic setting polymer insulator was measured for comparison

Partial discharge investigation on palm oil using needle – plane electrode configuration and electric field distribution using ANSYS Maxwell

The Partial Discharge Inception Voltage (PDIV) and PD characteristic of mineral oil were described and compared with palm oil. The test was performed by needle-plane electrode configurations. Both mineral- and palm oil were investigated under AC voltage. A comparison study between PDIV and PD activities of the mineral oil Hyrax and palm oil were investigated with the total volume of the oil in the test cell was approximately 2 L. The 50-μm tip radius of tungsten needle electrodes were utilized as high voltage electrode. On the other hand, the grounded electrode with 30-, 40-, and 50 mm gap distances was represented by a 50-mm and 75-mm diameter copper plane electrode. Consideration on the oil conditions' effect on both PDIV and PD characteristics was also carried out. It was clearly shown that PDIV is dependent on the electric field stress of the electrode system and the test method based on the experimental results. In comparison to differences of gap distance, the 50-μm needle tip radius and 75-mm plane with gap distance of 30-mm electrode revealed the highest electric field stress and inversely exhibited the lowest PDIV value tested. Furthermore, simulation using ANSYS Maxwell on the electric field distributions of the electrode systems was also performed. In order to quantify electric field based on the finite element methods the ANSYS Maxwell was being utilized. In the simulation, the palm oil and mineral oil properties of its 2D modelling test cell was used. From the results, the PD characteristics of mineral oil and palm oil tested by needle-plane electrode system are known. To confirm the suitability of palm oil as a high voltage insulating medium, it is vital to analyse in-depth on its partial discharge activity and characteristics

Effects of air humidity on the performance of a polymer insulator under lightning induced voltage conditions

Lightning induced voltage is one of the important issues pertinent to line interruptions in distribution lines. The behaviour of a polymer insulator under different weather conditions may affect the overall stability of a power flow in the line. In this paper, the lightning induced voltage due to a typical sample of return stroke current on a distribution line has been investigated, and the electrical behaviour of a polymer insulator (10 kV) under different air humidity conditions was analysed in detail. The results show that the air humidity has a direct effect on the electrical performance of a polymer insulator under lightning induced voltage conditions, which reduces the reliability of the system. Therefore, in designing new distribution lines and in modifying existing lines, various safety and protection parameters such as determining the critical distances around the distribution lines where lightning induced over voltage (LIOV) may occur, the humidity of air should be treated as an essential input parameter. Thus, the field propagation along an insulator based on recorded local information (weather conditions) can be helpful and should be taken into account in taking protection measures

On the effect of insulator angle with respect to the cross arm on the distribution of lightning electric fields

In this paper, the effect of insulator angle with respect to the cross arm on the electrical performance of a polymer insulator under lightning impulse voltage condition was studied and the results discussed accordingly. An insulator angle with the cross arm of other than 90° is usually due to defects in the connections or being under pressure from the line angles and it can be an important issue for the stability of the line against lightning. The results show that the insulator angle can play an important role in increasing the electric fields around insulator and thus increase the chance of electrical breakdown of the insulator