This paper presents modeling and simulation of maximum power point tracking (MPPT) used in solar PV power systems. The Fuzzy logic algorithm is used to minimize the error between the actual power and the estimated maximum power. The simulation model was developed and tested to investigate the effectiveness of the proposed MPPT controller. MATLAB Simulink was employed for simulation studies. The proposed system was simulated and tested successfully on a photovoltaic solar panel model. The Fuzzy logic algorithm succesfully tracking the MPPs and performs precise control under rapidly changing atmospheric conditions. Simulation results indicate the feasibility and improved functionality of the system. Keyword:Fuzzy logic algorithm Maximum power point tracking MPPT Photovoltaic Simulink Copyright © 2018 Institute of Advanced Engineering and Science.All rights reserved. Corresponding Author:Ahmad Saudi Samosir, Departement of Electrical Engineering, University of Lampung, No. 1, Jln. Prof. Soemantri Brojonegoro, Bandar Lampung, 35152, Indonesia. Email: ahmad.saudi@eng.unila.ac.id INTRODUCTIONThe growing energy demand of the world and the tremendous risk of climate change associated with the use of fossil fuels have driven research and development of alternative energy sources that are clean, efficient, renewable and environmentally friendly. Among all renewable energy sources, solar power systems attract more attention because they have several advantages such as pollution-free, low maintenance costs and low operating costs. Their sources of energy, which is derived from solar energy, are also widely available and it is free [1]- [4].In solar power system, the solar energy is directly converted into electrical energy by solar PV module. The main components of solar PV systems are solar cells made from semiconductor materials that have a photovoltaic effect, which serves to convert solar energy into direct current electricity. When exposed to sunlight; the solar panels will generate the direct current electricity, which is ready to supply power to the load. Solar Panels do not need much maintenance and have no moving parts. The unfavorable issue with solar PV systems is the high installing cost and the variation of energy form the solar panel with environmental conditions. In order to attain the maximum efficiency from the solar panel, it is important to obtain the maximum available power at any operating condition [5]. Also, the power distribution across the system has to be managed. Storage devices are used so that the energy is stored or supplied according to the availability of sufficient power and the load requirements [6].The efficiency of solar cells depends on many factors such as temperature, irradiance, spectral characteristics of sunlight, dirt, shadow, and so on. Changes in insolation on panels due to fast climatic changes such as cloudy weather and increase in ambient temperature can reduce the photovoltaic (PV) array

Intisari — Kerusakan transformator distribusi sering disebabkan oleh ketidakseimbangan beban, sehingga monitoring ketidakseimbangan beban transfornator distribusi perlu dilakukan. Letak dan lokasi transformator distribusi yang jauh dan tersebar mengharuskan monitoring harus dilakukan dari jarak jauh. Teknologi internet of things (IoT) dan komunikasi tanpa kabel mendukung monitoring dari jarak jauh. Makalah ini menyajikan perancangan dan pembuatan alat monitoring ketidakseimbangan beban transformator distribusi menggunakan teknologi IoT. Mikrokontroler Arduino digunakan untuk memproses data tegangan dan arus dari sensor, menghitung indikator ketidakseimbangan beban dan mengirim data hasil proses ke jaringan internet menggunakan Ethernet shield dan router yang diperlengkapi dengan modem. Thingspeak digunakan sebagai platform IoT. Hasil pengujian menunjukkan bahwa peralatan monitoring mampu bekerja dengan baik sehingga kondisi ketidakseimbangan beban transformator distribusi dapat dimonitor secara online dari jarak jauh menggunakan perangkat yang terhubung ke jaringan internet. Kata kunci — Monitoring, Ketidakseimbangan Beban, Transformator Distribusi, Internet of things.     Abstract — Damage to the distribution transformer is often caused by unbalanced load, so it is necessary to monitor the unbalanced load condition of the distribution transformer. The remote and dispersed location of distribution transformers requires remote monitoring. Internet of things (IoT) technology and wireless communication support remote monitoring. This paper presents the design and manufacture of distribution transformer unbalanced load monitoring tools using IoT technology. The Arduino microcontroller is used to process voltage and current data from sensors, calculate unbalanced load indicators and send process data to the internet network using an Ethernet shield and a router equipped with a modem. Thingspeak is used as an IoT platform. The test results show that the monitoring equipment can work properly so that the distribution transformer unbalanced load conditions can be monitored online remotely using a device connected to the internet network. Keywords— Monitoring, Unbalanced Load, Distribution Transformer, Internet of Things.

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A hybrid system utilizes several energy sources to generate electricity. This paper proposes combination of two renewable energies i.e. micro-hydro and photovoltaic for energy independent village application in Dusun Mergosari, Pesawaran Indah Village, Pesawaran Regency, Lampung Province. Previously, the village was only supplied by one micro-hydro generator through a long feeder line with high voltage drop along the line. In this work, an optimal placement and size of photovoltaic system is identified and studied through software simulation. The obtained results show that installation of a PV system improves grid's performances in terms of lower voltage drop and power losses. About 9.5% to 31% voltage improvements were observed in accordance with PV System installation.

Sistem tenaga listrik merupakan sistem interkoneksi antara pusat pembangkit, transmisi dan beban. Apabila terjadi gangguan pada salah satu sistem karena adanya beban lebih dan ketidakstabilan tegangan, akan berpengaruh ke sistem yang lain, maka perlu ada upaya untuk mencegah terjadinya gangguan tersebut. Salah satunya dengan mengetahui kemampuan pembebanan maksimum setiap beban agar kestabilan sistem dapat tetap terjaga dan dapat meminimalisir terjadinya pemadaman listrik. Penelitian ini bertujuan untuk mengidentifikasi bus-bus beban yang mendekati batas operasi yang diijinkan berdasarkan nilai λ dalam sistem interkoneksi Sumatera Bagian Selatan (Sumbagsel). Simulasi dilakukan dengan menggunakan Predictor - Corrector Method Continuation Power Flow untuk mendapatkan nilai λ dalam sistem tersebut. Dari hasil simulasi yang dilakukan, diperoleh nilai titik operasi dan titik jatuh dalam setiap beban sistem.Kata kunci : kemampuan pembebanan maksimum, bus-bus beban, titik jatuh An electric power system interconnection system is among a plant, transmission and load. In the event of disruption in one system due to overload and voltage instability, will affect other systems, it is necessary to attempt to prevent the occurrence of such disorders, one of them by knowing the maximum loadability of each load for voltage stability and minimalize cut off an electric. This study aimed to identify the load buses are approaching the limit of allowable operations based on the value of λ in the system interconnection South of Sumatera (Sumbagsel). Simulation is done using Predictor - Corrector Method Continuation Power Flow to obtain the value of λ in the system. From the simulation results, the value of the operating point and point load falls within any system. Keywords : maximum loadability, load buses, point load falls 1. PENDAHULUAN Pada saat ini, kebanyakan sistem tenaga listrik sudah merupakan sistem interkoneksi antara satu pusat pembangkit dengan pembangkit lainnya dengan harapan apabila salah satu dari pusat pembangkit atau saluran transmisi mengalami gangguan maka pasokan tenaga listrik tetap dapat berjalan. Di sisi lain, interkoneksi sistem tenaga listrik juga mempunyai beberapa kelemahan. Salah satu kelemahannya adalah apabila terjadi gangguan pada salah satu sistem karena adanya beban lebih dan ketidakstabilan tegangan, akan berpengaruh ke sistem yang lain. Gangguan yang pada awalnya bersifat sementara dan terjadi pada bagian si