Agus Purwadi

An LC filter design method for single-phase PWM inverters

In this paper, an analysis and design method of the output LC filter of single-phase PWM inverters is presented. At first, the analytical expressions for the total harmonics of the inductor current and capacitor voltage of the LC filter are derived. As the unique values of the parameters of the LC filter cannot be specified based on the total harmonic of the capacitor voltage alone an additional criterion based on the minimum reactive power of the LC filter is used to specify these parameters. Experimental results are included to verify the derived expressions.<<ETX>>

Prototype development of single phase prepaid kWh meter

The single phase prepaid kWh meter consists of energy metering and STS system, based on International Standard: IEC 62055-31, 62055-41, IEC 62055-51. The energy metering measure line voltage, current and calculates active, reactive apparent power, energy, power factor, and RMS voltage and current. There are two separate inputs to measure line, ground, and/or neutral current enabling the meter to detect tampering and to continue operating. Development of single phase based on needs of PLN, which is about 7 million units kWh meter up to year 2014, especially for new customer.

A new approach to synthesis of static power converters

A new approach to synthesis of static power converters is proposed in this paper. This new synthesis technique is based on combinational form of two-port networks. By using this synthesis technique we can utilize the advantage properties of existing static power converters to generate new static converters which meet our defined output characteristic. A new dc-dc converter which has a very high ratio between its output and input voltages is derived by using this technique. Several experimental results are included to show the basic characteristics of the proposed converter.

Prototype development of a Low Cost data logger for PV based LED Street Lighting System

The data logger is an electronic device that records data over time or in relation to location with a built in sensor. The need of data logger is to accomplish monitoring task of street lighting system based on PV Solar Cell in Jakarta province, especially in Thousand Island Regency. Existing PV LED street lighting has not equipped by data logger, therefore monitoring task is done by manually. Prototype developed based on a microcontroller, battery powered, and equipped with internal memory for data storage, and sensors. The system developed should be “Low Power Consumption”, “Low Cost”, portable and easily embedded inside the PV LED Street Lighting controller.

An easy speed measurement for incremental rotary encoder using multi stage moving average method

Classical theoretical algorithms to calculate rotation speed from incremental encoder information, frequency counting and period counting algorithm, delivers notable measurement error which is a function of rotation speed. This error will cause failure in overall motor control algorithm, resulting in both motor and drive failure. Furthermore, the needs of FPGA as high frequency clock calculation device in period counting algorithm made the implementation cost higher. Two stages moving average method was implemented to reduce error. In addition, DSP sampling time will be used to replace high frequency clock generated by FPGA. With these proposed methods, more accurate speed measurement result can be achieved and no FPGA needed to implement the algorithm. In addition, less data samples are needed compared to classical method. Implementation result in PMSM motor control shows that these methods are able to reduce quantization error that generated when measuring speed using rotary incremental encoder, showing no observable electrical or mechanical problem.

Study of hybrid PV-diesel power generation system at Sebira Island-Kepulauan Seribu

Sebira Islands is one of the islands in Kepulauan Seribu, Jakarta. This island located at the the north end of the Kepulauan Seribu and not connected to submarine power cable network so that the electricity on this island is limited and only rely on diesel generator set. The government of Jakarta in cooperation with PT. CNOOC and LAPI-ITB are planning to revitalize the system by rebuilding hybrid power system between Photovoltaic panel and Diesel generator set on Sebira Island. This paper aims to make an analytical study for determining the appropriate design. The design was simulated with Homer software and then analyzed technically and economically. In this paper, some design system has been proposed on different scheme. The design has been simulated and the sensitivity analysis has been made on changing of load and fuel cost. The analysis showed that the most feasible scheme to be applied on Sebira Island is the scheme with the percentage fraction of PV and Diesel between 50-70%.

The use of wind turbine structure for lightning protection system

Indonesa has a very good location for the source of renewable energy from wind. Wind turbin need a toll structure to get the good turbin performance. Indonesa is located at the equator and has lightning characteristic differ from the characteristic measured in sub-tropical region. The later one are used as the basic data for the international lightning protection standards. This research was carried out to evaluate the protection system for protecting the components of wind turbined againts tropical direct lightning strike to the structures or wing blades. The characteristic of structure and its components were analysized. Lightning strikes hit the blade as the highest structures of the turbine and the lightning current distributed through the components and dispersed it to the grounding systems. Due to the fact that the location of this wind turbine is in the tropical area such as Nusa Penida in Bali, the tropical lightning characteristic play an important role to determine the protection system for the components and the structures. This study analyze the protection system that allow the current flow to the grounding system without disturbing the electric converter, mechanics, and electronics performance of the turbine by using their own structures. Local lightning characteristics in the region and the protections system design were derived from this study according to the frame of IEC standards with the use of tropical lighning parameters.

State of Charge estimation method for lithium battery using combination of Coulomb Counting and Adaptive System with considering the effect of temperature

The needs of good State of Charge (SOC) estimation method for lithium batteries are very high, not only useful for battery protection, preventing under-discharged, controlling the battery management system, and increasing the battery life, but also to increase the useable battery power. To make an SOC estimation method, second order Thevenin dynamic battery model is chosen, where the impedance values change in accordance with the SOC level. Hybrid method, which combine Coulomb Counting Method and Adaptive System Method, is chosen here. Coulomb Counting method suffers a weakness in term of initial SOC value determination, while Adaptive System Method with its ability to adjust with changes in the system will be a solution for the mentioned drawback. It can be shown that the proposed SOC estimation model is able to function properly and fairly represent the lithium battery characteristic. The method can be used not only on the specific lithium battery, but can be used in various lithium batteries by updating the its Look-up table block. Simulation and experiment have been done to verify the proposed method.

Modelling and Simulation of Switched Reluctance Motor Based on Comsol

Switched reluctance motor (SRM) drives have gained many attentions from researcher which will be used for automotive applications that needs high speed, wider range of constant power capability, ruggedness, and fault tolerance. This paper focuses on modelling and simulation of switched reluctance motor (SRM) based on COMSOL software, two dimensional finite element models of SRM were developed and established. The results show that the models established, are propitious to the accurate analysis of switched reluctance motor torque and flux. SRM 6/4 configuration was selected due to its simple structure and low cost of electronics required for the controller. The model developed will be used to design and build an EV SRM for prototype testing.

A DC high-current low-voltage power generating system

A DC high-current low-voltage power supply is commonly used in electrochemical industries, welding machines, and cathodic protection systems. In this paper, a DC high-current low-voltage power generating system that is implemented by using a combination of a three-phase alternator and a rectifier is proposed. In the proposed system, a special rectifier topology that is suitable for high-current and low-voltage applications is proposed. A special generator that produced an almost trapezoidal voltage waveform has been designed.. Several experimental results are included in this paper to show the validity of the proposed concept. A 2 kVA high-current low-voltage generating system has been constructed.