Perancangan Kontroler DC Link Inverter Sisi Jala-jala pada Kondisi Faktor Daya 1 untuk Pembangkit Listrik Tenaga Bayu 100kW

Sistem kontrol pembangkit listrik tenaga bayu (PLTBayu) 100kW yang sedang dirancang bangun di Pusat Penelitian Tenaga Listrik dan Mekatronik (Puslit Telimek) LIPI memakai inverter 3 fasa yang dipasang pada sisi jala-jala. Inverter ini berfungsi menyalurkan daya listrik yang dibangkitkan oleh generator induksi 3 fasa dari DC link saat operasi dan menyalurkan daya listrik dari jala-jala ke DC link saat start up. Saat melakukan fungsinya inverter ini perlu dikontrol untuk  menjaga tegangan DC link pada kisaran nilai yang diinginkan. Makalah ini bertujuan untuk merancang kontroler tegangan DC link untuk inverter sisi jala-jala. Kontrol dc link terdiri dari kontrol umpan balik PI dan kontrol umpan maju dari arus yang masuk dari sisi generator. Pada makalah ini digunakan sinusoidal Pulse Width Modulation (PWM)  dengan dan tanpa penambahan sinyal urutan nol (ZSS). Dari hasil simulasi ditarik kesimpulan: (a) kontroler DC link yang telah dirancang mampu mencapai tegangan referensi yang diinginkan, (b) modulasi dengan tambahan sinyal urutan nol memberikan tanggapan tegangan DC link yang lebih baik dari pada modulasi tanpa tambahan sinyal urutan nol, dan (c) modulasi dengan tambahan sinyal urutan nol memberikan faktor daya yang lebih mendekati 1 dari pada modulasi tanpa tambahan sinyal urutan nol.Kata kunci: tenaga bayu, pembangkit listrik, inverter 3 fasa, kontrol tegangan dc link, kontrol umpan balik, kontrol umpan maju, sinusoidal PWM, ZSS

Dual Carrier PWM Inverter-Fed Nine-Phase AC Motors

In many applications such as electric vehicles, dual mode operation is needed, i.e pulsewidth modulation (PWM) mode for low speed region and squarewave mode for high speed region. The latest research has shown that symmetrical ninephase motor could provide optimal characteristics under dual mode operation, i.e. minimum nverter input and rotor current ripples. By using analytical calculation, in this paper the authors show that asymmetrical nine-phase motor can also provide the optimal characteristics under dual mode operation by simply using dual carrier PWM. This finding is supported by experimental results

Perancangan Kontroler DC Link Inverter Sisi Jala-jala Pada Kondisi Faktor Daya 1 Untuk Pembangkit Listrik Tenaga Bayu 100kW

Sistem kontrol pembangkit listrik tenaga bayu (PLTBayu) 100kW yang sedang dirancang bangun di Pusat Penelitian Tenaga Listrik dan Mekatronik (Puslit Telimek) LIPI memakai inverter 3 fasa yang dipasang pada sisi jala-jala. Inverter ini berfungsi menyalurkan daya listrik yang dibangkitkan oleh generator induksi 3 fasa dari DC link saat operasi dan menyalurkan daya listrik dari jala-jala ke DC link saat start up. Saat melakukan fungsinya inverter ini perlu dikontrol untuk menjaga tegangan DC link pada kisaran nilai yang diinginkan. Makalah ini bertujuan untuk merancang kontroler tegangan DC link untuk inverter sisi jala-jala. Kontrol dc link terdiri dari kontrol umpan Balik PI dan kontrol umpan maju dari arus yang masuk dari sisi generator. Pada makalah ini digunakan sinusoidal Pulse Width Modulation (PWM) dengan dan tanpa penambahan sinyal urutan nol (ZSS). Dari hasil simulasi ditarik kesimpulan: (a) kontroler DC link yang telah dirancang mampu mencapai tegangan referensi yang diinginkan, (b) modulasi dengan tambahan sinyal urutan nol memberikan tanggapan tegangan DC link yang lebih baik dari pada modulasi tanpa tambahan sinyal urutan nol, dan (c) modulasi dengan tambahan sinyal urutan nol memberikan faktor daya yang lebih mendekati 1 dari pada modulasi tanpa tambahan sinyal urutan nol

Optimum Phase Number for Multiphase PWM Inverters

This paper investigates the optimum phase number for multiphase PWM inverters. The input current ripple is used as  a  performance  indicator.  Analysis results  show  that  phase number more than nine cannot provide significant input current ripple reduction. Experimental results are included in this paper to show the validity of the proposed analysis method

Replacement of Analog Automatic Voltage Regulator using Digital Technology

Before the 90’s, many power plants in Indonesia were equipped with analog controllers and now those power plants are still in operation to produce electricity. One of those controller parts is Automatic Voltage Regulator (AVR). If a failure occurs in the AVR, the economic solution is by replacing the damaged electronic component with new component. However this method will not solve the problem if the components are not available in local market or become obsolete. Purchasing the new AVR that compatible with other controller parts cannot be done again because the analog controllers are no longer produced by the vendor. Furthermore, replacement of all the controllers with the current technology become expensive.  According to this, an alternative solution is proposed in this paper by designing an AVR that compatible with other controller parts and considering the availability of the electronic components in local market. ATmega8 microcontroller is used to implement a digital AVR and employing op amp based as its signal conditioning. The result shows that the digital AVR can reduce hardware size and power consumption. The digital AVR also meets the computation rate of the computation signal

Feasibility analysis of the conversion of brushed to brushless direct current motor

This paper analyzes the feasibility of converting brushed direct current (BDC) to brushless direct current (BLDC) motor by substituting the wound rotor with a permanent magnet. The aim is to overcome the low quality of rewinding of wound rotors. The conversion was performed by redesigning the motor, referring to the old stator dimensions and motor specifications. Some suitable speed control systems were also examined. Technical analysis was executed by simulating motor characteristics, covering torque-speed curve, cogging, and ripple torques. Afterward, an economic analysis was done to determine the cost of making one rotor unit and the speed control and then compare it with the price of a new BDC motor with equivalent power. The results show that the motor produces 3.6 kW, 18.86 V, 176.71 A, and 28.53 Nm at 2,460 rpm with 2 phases configuration. The maximum cogging torque is 2.9 Nm. The cost of making one rotor unit plus speed control is higher than that of a new BDC motor. These results show that it is technically feasible to convert BDC into a BLDC motor but not economically or vice versa

Desain Dan Implementasi Sistem Kendali CNC Router Menggunakan PC Untuk Flame Cutting Machine

This paper focuses on design of router control systems based on computer numerical control (CNC) using personal computer (PC) implemented in flame cutting machine (FCM). NC-Code entered into the computer translated to be a command signal sent by the PC to a microcontroller to control the end effector's movement alongthe X and Y axis simultaneously based on linear and circular interpolations calculation on the PC. This control system is implemented on FCM by connecting the output control of the microcontroller with the driver actuator of the FCM in the form of a DC motor. The obtained result is in the form of a CNC router control system prototype to be implemented in the FCM which is capable to perform linear interpolation and circular interpolation

Selection Method of Modulation Index and Frequency ratio for Getting the SPWM Minimum Harmonic of Single Phase Inverter

Harmonic content is an important parameter in relation to the power generated by inverter. In power conversion technology of inverter, sinusoidal pulse width modulation (SPWM) is the most popular used by many researchers. The advantages of SPWM inverter operation as a conversion technique compared to other inverter types can be seen from the low harmonic distortion in the output voltage of inverter. Therefore, the SPWM signal generation process becomes a determining factor for the performance of the overall system. This paper present the method for selecting the modulation index (ma) and frequency ratio (mf) using Cubic Spline Interpolation to get minimum harmonic of SPWM inverter that generated. Both parameters controlled with varied values digitally using microcontroller to generate SPWM, then the output of inverter with and without LC filter was investigated. The results show that the use of Cubic Spline Interpolation method in the selection of ma and mf precisely managed to produce SPWM inverter with minimum harmonic content. At the inverter output, the use of LC filter is not only useful for converting SPWM signals to sinusoidal waveforms but can also reduce harmonic content significantly less than 3 %

Performance of low-cost solar radiation logger

In solar power systems, irradiance value data are among the most important parameters. Such data can be used in installing photovoltaic (PV) modules, such as determining the exact location, tilt angle, and required area, for optimal power efficiency. In this study, the comprehensive simulation and implementation of a solar radiation meter with a PV cell and temperature sensor are presented. The irradiance measurement value is based on the power reading generated by the small capacity of the PV cell at a specific load converted into a digital value in the microcontroller using the implicit Newton polynomial interpolation (NPI) equation as a low-cost alternative method. The effect of temperature is included in the conversion to obtain precise measurement results. Firstly, the structure and characteristics of the PV cell are discussed. Secondly, the parameters, measuring method, and conversion of the measurement reading data using the NPI equation are presented to assess the results. Finally, the simulation of the solar radiation meter using the PSIM and implementation of the hardware are conducted to validate the concepts and compare their results. The proposed hardware has an average error of 2.72% in the implementation of the measurement test