Partial discharges (PD) are the most common and harmful threat to the health of electrical insulation of high voltage (HV) and high field (HF) equipment. The occurrence of PD activity in HV and MV equipment is at the same time a cause and a sign of insulation degradation that may eventually result in the breakdown of the HV power equipment. For the safe and reliable operation of HV power equipment, continuous PD monitoring needs to be conducted conveniently to prevent any unplanned power outages and damage to electrical power equipment. The ultra-high frequency (UHF) PD measurement method has been widely used as an effective technique to detect PD activity on HV power equipment due to its non-invasive principle. To enable PD detection accuracy, there is still a need for more sensitive PD sensors that can assist the UHF PD monitoring system by suppressing ambient background noise and low-frequency electromagnetic interferences from telecommunication such as GSM signals. To tackle the sensitivity issues, this article presents a new design of ultra-wideband (UWB) microstrip patch antenna that is capable of effective suppression of low-frequency interference signals. The proposed antenna, designed, simulated, and optimized using the CST Microwave Studio software, has a bandwidth of 3.3GHz, below -10dB, in the operating frequency range of 1.2GHz-4.5GHz. The prototype of this antenna, printed on an FR4 substrate of a thickness of 1.6mm and a dielectric constant of 4.4, featuring a compact size of 100mm $\times100$ mm $\times1.6$ mm, was implemented to detect PD through laboratory experiments. This paper shows that the designed UWB antenna has high sensitivity, good noise rejection and it is, therefore, a promising candidate sensor for PD detection on HV equipment.

This article presents a design of ultra-high frequency (UHF), ultra-wide band (UWB) antenna used for partial discharge (PD) detection on high voltage and medium voltage power system equipment. The proposed UHF antenna has a working frequency band of 1.2GHz-4.5GHz, covering a total bandwidth of 3.3GHz with a return loss of less than -10dB in the entire antenna’s operating frequency. The computer simulation technology (CST) Microwave Studio software was used to design, simulate and optimize the proposed antenna. Upon simulation and optimization process, the antenna prototype was fabricated on the FR-4 substrate of 1.6 mm thickness and dielectric permittivity of 4.4. This antenna has a compact size of 100mm $\times100$ mm.The radiating patch and the ground plane of this antenna are made of annealed copper whose thickness is 0.035mm. The simulations and measurement results for the proposed antenna are in a good agreement, and the return loss of this antenna is less than −10dB with voltage standing wave ratio, VSWR, < 2 within the frequency range of interest. The proposed antenna performance in PD sensing is compared with a commercial high-frequency current transformer, HFCT. To validate the sensitivity performance of the designed antenna, experimental PD measurements were carried out by using an epoxy slab inserted between two parallel plates electrode model, in order to generate surface discharge on the insulator, and using a needle-plate electrode configuration to generate corona discharge in transformer oil. Based on PD measurement results, it was shown that the designed antenna has a high sensitivity, which make it a suitable candidate for UHF partial discharge monitoring on high voltage and medium voltage power assets.

Many studies have been conducted on the implementation of game theory approaches in optimizing energy trading and scheduling in multi-microgrid (MMG) systems, both in cooperative and non-cooperative games. This is because game theory is a rich field of study that can illustrate the self-interest nature of each player, in this case, each agent in the MMG system. However, there are still various issues in its implementation, both technical and non-technical. This article will focus on a systematic review of various relevant and credible literature papers on the game theory-based on-grid MMG topic using the Kitchenham method. The on-grid MMG system differs from the off-grid MMG system in that each MMG is connected with the conventional grid. This connection provides more flexibility in operation and various features, including multi-level interactions beyond peer-to-peer, asymmetric agents, the presence of distribution network operator, support and backup power from the grid, and an energy market pool. This literature review is done by collecting, analyzing, and understanding the issues and challenges in the implementation, the types of games and algorithms, techniques, and solution approaches used, as well as determining how far each game and existing solution can solve these problems. From the systematic review result, in general there are two types of games that can be played between agents: cooperative and non-cooperative, each with its own pros and cons. The technical issues and solutions in these games have been summarized with particular concern related to power systems, renewable energy, energy storage, agent interests, uncertainties, ICT, privacy and security, computation solutions, mechanisms, and cost and revenue. Research and future works recommendation related with on-grid MMG game theory subject is also described.

International Journal on Electrical Engineering and Informatics is a quarterly publication peer reviewed journal in electrical engineering and informatics.

The development of printable ultrahigh-frequency (UHF) antennas as partial discharge (PD) sensors for high-voltage equipment has been extensively studied. However, achieving ultrawideband (UWB) UHF PD sensors frequently requires larger sizes, unsuitable for certain applications requiring compact sensors for dielectric windows in HV equipment. This research objective is to obtain PD sensors with a wider bandwidth (0.3–3 GHz) and a compact size fitting a less-than-100mm-length gas-insulated switchgear (GIS) dielectric window. A circular patch microstrip antenna (CPMA) was chosen for its small size and potential for UWB performance. This paper discusses the design modification of the CPMA to obtain a wider bandwidth for PD detection in GIS. Simulations and lab-scale experimental verifications were conducted to evaluate the optimized sensor. The modified sensor, with a size of 60 × 73 mm², achieved a bandwidth of 3.08–3.14 GHz, a reflection coefficient of -44 dB, and several resonant frequencies of 0.3–2.3 GHz. This is a seven-time wider bandwidth compared to earlier bowtie antennas while keeping a dimension of less than 100 mm². These properties allow for efficient PD detection in GIS and other insulating media. Experimental results indicate the sensor's capacity to reliably detect and analyze PD signals while responding appropriately to variations in voltage. Doi: 10.28991/ESJ-2024-08-05-03 Full Text: PDF

This paper deals with the occurrence of Partial Discharges on electrical equipment due to the high electric field exceeding the electric strength of Air. We can model PD occur in electrical equipment by using 4 types of electrode arrangement. There are Needle-Plane, Needle-Sphere, Needle-Needle, and Needle-Sphere. In this experiment, 4 types of electrodes with 10 mm gap between the two electrodes were used to produce a high electric field. PD measurement was conducted using phase-resolved measurement system which able to measure the PD magnitude, phase of PD occurrence as well as PD number. The task was done using a digital oscilloscope combined with a personal computer. The analysis of the PD data was conducted by utilizing phase-resolve PD pattern patterns. The experimental results showed that PD took place at around the peak of the applied voltage. Phase-resolved analysis indicated that partial discharge magnitude as well as partial discharge occurrence were strongly dependent on the instantaneous applied voltage. The simulation was able to generate phase-resolve PD pattern patterns similar to those obtained from the experiment.