Better understanding of the electrical behavior of miniaturized electrical devices is largely supported by the need to reduce losses and to prevent operational failure caused by electrical breakdown or electrical discharge. In large scale electrode separation, the breakdown voltage is well described by the Paschen's law. However, when the inter-electrode gaps are below 10 µm a departure from the Paschen's law is observed. The current research is focused on development of methodology for analysis of the electrical breakdown behavior in micrometer gaps and the description of the underlying mechanisms. The experiments were performed for interelectrode gaps from 1 µm to 10 µm by using piezoelectric system to control the separation in tip-to-plane configuration for which a divergence of the electric field is imposed. The obtained results show that the field electron emission enhanced by the thermionic emission becomes the main mechanism for electrical breakdown under the above conditions.

Interruptions due to vegetation frequently occur at the distribution line in Indonesia. Follows to that, the distribution utility decided to replace the bare conductor with the one-layer XLPE cable. However, new problems occurred mainly at the link between the XLPE cable and the post insulator on each of distribution pole. The high permittivity material of XLPE and the ceramic insulator enhance the local electric field that produces pinholes on cables. In the later phase, the pinholes become more extensive and if there is a lightning strike that causes a voltage that exceeds the Basic Insulation Level of the insulator, then the electric arc will flow from the conductor to the ground isolator through the pinhole. This paper proposed a novel design to cover the cable, including its accessories. Based on a simulation using a finite element analysis, the electric field stress is reduced by the following steps: 1. Add a semiconductor layer on the XLPE layer, 2. Replace the ceramic insulator with the polymer one, 3. Modify the binding between the cable and the post insulator by using a unique clamping method.

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High efficiency electrical equipment usage is an alternative solution to support carbon emission reduction in Indonesia. In this research, new distribution transformer design using amorphous metal core (AMDT) was evaluated by conducting laboratory testing and field installation. According to the laboratory test result upon 4 samples, AMDT had 60.91 – 67.35% smaller no-load loss but 0.58 – 9.79% higher load loss compared to national standard requirement (although the load loss value of AMDT was within total losses tolerance). One AMDT sample failed during impulse test which should be followed up further by conducting insulation testing and design evaluation. Since the AMDT sample used 5-legged core design, the weight of the AMDT was heavier than conventional cold rolled grained oriented (CRGO) silicon steel transformer; thus, the construction planning and design should be re-evaluated for AMDT installation. According to total cost calculation based on life cycle approach by using obtained data and related assumptions, it was found that AMDT would potentially give higher economic benefit than conventional CRGO silicon steel transformer when the load factor (LF) is below 79% for 100 kVA AMDT, below 78% for 50 kVA AMDT, and below 68% for 25 kVA AMDT.

Surge arrester is a critical component in tropical countries since the likelihood to have a lightning stroke in the transmission system is higher in comparison to those in sub tropics. Therefore, assuring the reliability of this component is important. However, the surge arresters are sometimes being overlooked during the replacement plan because of its insignificant price in comparison to the protected assets. Transmission utility mostly just install and forget. This paper presents a methodology to replace the High Voltage (HV) and Extra High Voltage (EHV) surge arresters based on the risk of a failure. The condition assessment based on resistive leakage currents and the statistical reliability curve based on lifetime assessment define the likelihood of failure. While the consequences are based Safety, Extra Fuel Cost, Energy Not Served (ENS), Customer Satisfaction, Leadership, and Environmental Impact. The risk is then estimated by multiplying the likelihood of failure and consequences. It can be used to prioritise replacement, particularly when resources (budget, spares, workability) are limited.