Modification and Optimization of Circular Patch Microstrip Antenna (CPMA) for Partial Discharge Detection against High Voltage

The result of the modified reference antenna is based on predefined parameters by optimizing each parameter namely r1, r2, and L for partial discharge detection of high-voltage, parameter r1 shows the largest bandwidth when r1 is changed by 10mm of 5.36 GHz. However, the reflection coefficient and VSWR values at 15mm are better if we compare them to 5mm and 10mm. Parameter r2 shows that the largest bandwidth shown after we changed the size by 6mm of 5.37GHz is better than 3mm and 9mm. However, the reflection coefficient value at 9mm is better than 3mm and 6mm. Simulation results on parameter L based on Fig. 6 show that the largest bandwidth when parameter L is changed to 3mm is better than 2mm and 4mm, but the reflection coefficient value at 4mm is better than 2mm and 3mm, and for VSWR value 2mm is better than 3mm and 4mm. Modification antenna has roughly omnidirectional radiation patterns is 1.96dBi for r1 = 5; r2 = 3; slot = 2; 2.07dBi for r1 = 10; r2 = 6; slot = 3; 2.03dBi for r1 = 15; r2 = 9; slot = 4, the operating frequency band between 1.5 GHz, which is the frequency of interested for PD occurrence. For a voltage of 7 kV, the modified antenna can detect positive and negative cycle partial discharge of 115nPos, while the reference antenna is 80nPos. For a voltage of 8 kV, the modified antenna can detect partial discharge positive and negative cycles of 51nPos, while the reference antenna is 19nPos. For a voltage of 9 kV, the modified antenna can detect partial discharge positive and negative cycles of 27nPos, while the reference antenna is 14nPos.