STUDY ON SATURATION CONSIDERATION AND ITS INCORPORATION INTO INDUCTION MOTOR MODELLING

Kejenuhan magnetik dapat menimbulkan efek yang dapat merugikan atausebaliknya bahkan menguntungkan serta diinginkan. Kejenuhan magnetik sangat penting untukdiperhatikan namun tidak mudah untuk ditangani dan dimodelkan. Dalam berbagai kajianpenerapan mesin tak serempak, induktansi pada umumnya dianggap konstan dan tidakterpengaruh oleh adanya kejenuhan magnetik yang dapat terjadi dalam berbagai kondisioperasi.. Akibatnya pemodelan mesin tidak menggambarkan kondisi mesin sebenarnya padasaat dioperasikan dengan tingkat kejenuhan tertentu. Tulisan ini mengkaji beberapa pendekatanuntuk memperhitungkan tingkat kejenuhan magnetik dalam motor tak serempak sertabagaimana menerapkannya dalam pemodelan motor untuk memperkirakan berbagaikarakteristiknya

Energy Saving Through Design Optimization Of Induction Motors

In this article, basic concepts and general procedures in induction motor design and optimization are described. Beginning with the definition of design problem, some design objectives are distinguished based on the type of power supplies as well as motor applications. Some basic equations relating output characteristics to motor physical dimensions are given and two different design approaches are highlighted. The design optimization is explained by giving the definition of design variables and parameters, objective functions, constraint functions and the general technique of optimization. As examples, two motor designs with special objectives, including loss-minimization as well as wide speed-range operation, are presented

Kajian terhadap Upaya Penghematan Energi pada Aplikasi Motor Kapasitor

Makalah ini membahas suatu contoh upayapenghematan energi pada aplikasi motor kapasitor.Dengan mengambil inspirasi dari salah satu karya patenFrank Nola dari NASA, suatu peralatan semikonduktoryaitu TRIAC dipilih sebagai konverter daya dalamimplementasi algoritma penghematan energi. Suaturangkaian elektronika sederhana dirancang dan dibuatuntuk memicu bekerjanya TRIAC. Agar secarainstruksional lebih bermanfaat, disertakan pula contohhasil pemilihan nilai komponen-komponen elektronikayang digunakan. Hasil percobaan di laboratoriummenunjukkan bahwa penggunaan TRIAC untukmengurangi konsumsi energi listrik terbuktimenguntungkan jika digunakan pada aplikasi motorkapasitor yang pada sebagian besar rentang waktuoperasinya berbeban rendah, misalnya pada aplikasipompa. Hal ini dimungkinkan karena pengurangantegangan efektif masukan ke motor akan menyebabkanpengurangan daya masukan, disertai dengan perbaikanfaktor daya dan efisiensi motor. Kata Kunci—hemat energi, motor kapasitor, TRIA

Hybrid Improved Differential Evolution and Splinebased Jaya for Photovoltaic MPPT Technique

Some Soft Computing algorithms to solve themaximum power point tracking (MPPT) method problem ofthe photovoltaic system under partially shaded conditions willstop tracking Global Maxima and produce reference voltage orthe best duty-cycle if the difference between the worst and thebest candidate solution is smaller than the specified threshold.A large threshold value will produce fast converging, but theaccuracy value will be low, and vice versa, then thedetermination of the threshold value will be very dilemma.Therefore, this study proposed a combination of ImprovedDifferential Evolution (IDE) and Jaya optimization based onpredictive curves using cubic spline interpolation to determinethe best particles after the IDE reaches convergent criteria, sothat with a large threshold value it will still get high accuracyand high convergent speed. Furthermore, the algorithmproposed in this study is known as Improved DifferentialEvolution and Jaya Based Spline (IDESJaya). The proposedalgorithm is compared with conventional P&O, Jaya based onSpline, and IDE. Simulation results show that the IDESJayatechnique is faster converging, provides a better overalltracking efficiency and higher accuracy

Lifetime Prediction of Lead-Acid Batteries in Base-Transceiver Station

The battery is an essential component in providing continuous electricity supply using renewable energy sources. It can be found in many daily applications, such as in the telecommunication system, radio microwave system, emergency lighting, the backup system of power plants, even in a photovoltaic system. It is often used as the backup source in case of a failure in the main supply system. The duration of how long the battery can still supply energy to loads without being charged is defined as the battery autonomy day. If during its daily utilization the battery often exceeds its autonomy day, it can result in the deterioration of the battery lifetime. It produces the deviation of the battery lifetime specification which has been previously determined by the manufacturer. This paper presents the results of battery lifetime prediction at a base-transceiver station (BTS) of Telkomsel Company in Indonesia. It has two main purposes which are to evaluate the policy of autonomy day and to predict the remaining lifetime of the battery before reaching its time limit. The obtained results show that there have been some alterations from the batteries’ former policy of autonomy day, from 72 hours to 43.03 hours and 43.26 hours for both existing batteries respectively with considered depth-of-discharge (DOD) of 20%. By using a linear data curve fitting, the results of calculation and analysis indicate that the remaining useful lifetime of both batteries were 5.72 years and 5.77 years. Another approach using an exponential data curve fitting resulted in the remaining lifetime of 7.12 years and 7.16 years for both batteries respectively

Kontribusi Terhadap Kuliah Perancangan Mesin Listrik Dalam Pendidikan Teknik Tenaga Listrik Di Indonesia

Dalam dunia industri, mesin tak serempak banyak digunakan sebagai penggerak utama. Selain itu, sebagai generator mesin ini memungkinkan pembangkitan energi listrik secara otonom di daerah-daerah terpencil. Mengingat pentingnya peran mesin ini, makalah ini dibuat untuk sedikit memberikan kontribusi dalam kuliah perancangan mesin listrik bagi mahasiswa teknik tenaga listrik pada khususnya. Kontribusi yang diberikan berupa tambahan pemahaman terhadap penerapan teori elektromaknitik dalam perhitungan induktansi bocor cincin ujung rotor sangkar saat perancangan mesin tak serempak. Akan ditunjukkan bagaimana beberapa anggapan penyederhanaan diambil agar memungkinkan proses perhitungan dengan menggunakan teori dasar elektromaknetika. Perhitungan analitik berdasarkan metoda bayangan, yang pada umumnya sudah dipelajari dalam kuliah dasar teori elektromaknitik, dibandingkan dengan perhitungan secara analitik-empirik serta dengan perhitungan menggunakan metoda numerik berdasarkan metode elemen terbatas. Dengan memanfaatkan metoda bayangan, induktansi diperoleh melalui penghitungan fluksi yang tercakup total menggunakan vektor potensial. Sebagai pembanding, induktansi juga telah diperoleh dengan menghitung impedansi cincin. Selanjutnya, perhitungan induktansi menggunakan perangkat lunak berdasarkan metoda elemen terbatas juga telah dilakukan melalui penghitungan energi maupun fluksi. Hasil perhitungan analitik menunjukkan adanya kesesuaian dengan hasil numerik, dengan keuntungan metode bayangan lebih sederhana dan mudah untuk diterapkan dibandingkan dengan metode elemen terbatas yang hingga kini seringkali masih terbentur pada lama proses penghitungan serta keterbatasan daya hitung komputer

Optimization of the Thyristor Controlled Phase Shifting Transformer using PSO Algorithm

The increase of power system demand leads to the change in voltage profile, reliability requirement and system robustness against disturbance. The voltage profile can be improved by providing a source of reactive power through the addition of new power plants, capacitor banks, or implementation of Flexible AC Transmission System (FACTS) devices such as Static VAR Compensator (SVC), Unified Power Flow Control (UPFC), Thyristor Controlled Series Capacitor (TCSC), Thyristor Controlled Phase Shifting Transformer (TCPST), and many others. Determination of optimal location and sizing of device injection is paramount to produce the best improvement of voltage profile and power losses reduction. In this paper, optimization of the combined advantages of TCPST and TCSC has been investigated using Particle Swarm Optimization (PSO) algorithm, being applied to the 30-bus system IEEE standard. The effectiveness of the placement and sizing of TCPST-TCSC combination has been compared to the implementation of capacitor banks. The result showed that the combination of TCPST-TCSC resulted in more effective improvement of system power losses condition than the implementation of capacitor banks.  The power losses reduction of 46.47% and 42.03% have been obtained using of TCPST-TCSC combination and capacitor banks respectively. The TCPST-TCSC and Capacitor Bank implementations by using PSO algorithm have also been compared with the implementation of Static VAR Compensator (SVC) using Artificial Bee Colony (ABC) Algorithm. The implementation of the TCSC-TCPST compensation with PSO algorithm have gave a better result than using the capacitor bank with PSO algorithm and SVC with the ABC algorithm

Design of Inverter with Less Harmonics using Buck-Boost Converter and SPWM Method

In a power distribution system it is expected that the current and voltage values to be maintained constant both in terms of magnitude and frequency. However, distortion of waveforms as a result of non-linear loads connected to system is widely found in a form of harmonics. Harmonics are sinusoidal signals whose frequencies multiples of the fundamental frequency. The severity of harmonics content is commonly stated using Total Harmonics Distortion (THD), revealing the ratio of the Root Mean Square (RMS) values of all harmonic components to its fundamental component, and is expressed in percentage (%). The harmonics could engender undesired effects in some appliances. In this paper, an effort to minimize the THD value in an inverter design is described. Less harmonics were obtained using Buck-Boost Converter and Sinusoidal Pulse Width Modulation (SPWM) Method. Analysis results showed a THD reduction of 4.58 % and 4.33 % for current and voltage respectively