A. P. Hutomo, I. P. Buditomo, A. P. Putra, S. Suhariningsih, S. D. Astuti,
Volume 15, Issue 4 (December 2019)
Abstract
The Functional Electrical Stimulator design using monophasic spike-exponential waveform was proposed and described in this study. The monophasic square waveform has benefit in generating an action potential, but it could cause side effects such as toxic caused by the electrode polarization. The square waveform signal which the frequency and pulse width could be modulated was manipulated to be the monophasic spike-exponential waveform. Transformer OT240 was applied at the end of the FES system part and functioned as a voltage amplifier and DC signal isolator. On every frequency range between 5–100 Hz, the 16 peak voltage stages with the lower limit of 45 Volt and an upper limit of 400 Volt was arranged to obtain VRMS value in each stage. Characterization result shows that the produced waveform was monophasic spike-exponential with the narrow pulse width (t1/2 = 7 µs) and VRMS in the maximum frequency and peak voltage was 8.99 Volt. This study showed that the designed FES had high VP and low VRMS, thus, it could be concluded that this FES system design could be a candidate for its application.
Mohamad Almas Prakasa, Mohamad Idam Fuadi, Muhammad Ruswandi Djalal, Imam Robandi, Dimas Fajar Uman Putra,
Volume 20, Issue 3 (September 2024)
Abstract
The unbalanced load distribution in the electrical distribution network caused crucial power losses. This condition occurs in one of the electrical distribution networks, 20 kV Tarahan Substation, Province of Bandar Lampung, Indonesia. This condition can be maintained using optimal reconfiguration with the integration of Distributed Generation (DG) based on Renewable Energy (RE). This study demonstrates the optimal reconfiguration of the 20 kV Tarahan Substation with the integration of the Photovoltaic (PV) and Battery Energy Storage System (BESS). The reconfiguration process is optimized by using the Firefly Algorithm (FA). This process is conducted in the 24-hour simulation with various load profiles. The optimal reconfiguration is investigated in two scenarios based on without and with DG integration. The optimal configuration with more balanced load distribution conducted by FA reduces the power losses by up to 31.39% and 32.38% in without and with DG integration, respectively. Besides that, the DG integration improves the lowest voltage bus in the electrical distribution network from 0.95 p.u to 0.97 p.u.
