Fransisco Danang Wijaya

Design and analysis of tri core permanent magnet linear generator for wave energy conversion in south coast of Java Island

The south coast of Java Island has significant wave height that allows for wave energy to electric energy conversion. Wave energy converter using permanent magnet linear generator (PMLG) attracting more attention due to its efficiency of the generator and the elimination of translational to rotational motion converter in the generator, but PMLG suffer from electric power losses in the winding. In this paper, a tri core PMLG design which has minimum electric power losses is proposed. The electric power losses in the winding are ideally minimized using simulated annealing algorithm. Then, finite element analysis is used to analyze and verify the proposed design of PMLG. The small scale optimum design of this PMLG is simulated using an oscillating water column (OWC) chamber to analyze and investigate the performance of this linear generator. Simulation result shows that PMLG has a good efficiency and confirm the capability of this PMLG installed with OWC chamber in the south coast of Java Island.

Magnetic flux distribution due to the effect of stator-rotor configuration in the axial machine

This paper aims to look at the distribution pattern of the magnetic topology resulting from two different axial machines which are dual rotor with an internal stator (RSR) axial generator and dual stator with an internal rotor (SRS) axial generator. The simulation was performed with the finite element method software FEMM 4.2 using symmetry analysis which considers all parts of identical geometry. In this software will see the pattern of the magnetic flux distribution as well as the effects on axial machine. The output obtained from the magnetic flux distribution pattern can be either air-gap magnetic flux density, anchor reaction flux density, induced electromotive force and the electromagnetic torque generated.

Analytical design and optimization of flat-quasi linear generator for sea wave power plant in South Java Ocean

This paper aimed to find out a model of 1 kWp flat-quasi linear permanent magnet generator (LPMG) for ocean wave power plant in South Java Ocean. First, a flat-quasi LPMG is modeled based on the wave characteristic at the placement site. The model was then simulated using finite element software of FEMM 4.2. Next, the model was optimized to find out the optimum output power and cogging force. The optimization was performed by modifying poles length and number but constant total translator length. The optimized model could generate up to 1,424.65 Wp (6% higher output power), with 38.85% lower cogging force than the initial model. The output power was maximum when the load resistance equals 1 Ω. Based on the configuration of the LPMG and wave characteristic, the generator generates power only in certain time. This is due to different size between the wave amplitude and the translation path length. Moreover, the average wave height would be directly proportional to the translation speed, induced voltage, and output power.

Quantum neural network for State of Charge estimation

State of Charge (SoC) estimation is one of the most important parts of Battery Management System (BMS). Inaccurate estimation of SoC may cause overcharge or overdischarge which could lead permanent damage to battery cells. Neural Network (NN) models can yield quite accurate SoC estimation. However, the computation effort is also quite huge and it takes long time training. To improve the performance of NN, a new battery SoC estimation method based on Quantum Neural Network (QNN) is proposed. Results show that QNN is more computation efficient and yields more accurate results, when compared to the conventional NN and other methods such as Coulometric Counting (CC) and Open Circuit Voltage (OCV) prediction methods.

Aplikasi Magnetic Energy Recovery Switch sebagai Dynamic Voltage Restorer pada motor Induksi

Renewable energy source likes solar panel and wind turbine have intermittent character from instability power source generated. The instability power source can make dip voltage in power grid which happen in half cycle until few seconds. To stabilize the voltage in power grid from dip voltage, some methods have been developed using power electronics technology like VSI inverter, STATCOM, energy storage, OLTC, and MERS. The power electronic circuits have some advantages, such as small dimensional size and lightweight to keep voltage in power grid. In this paper, the MERS circuit was applied in induction motor which has small full bridge circuit, uncomplexity computation, and low switching frequency, so it needs low end hardware requirement. This paper proposed the use of MERS dc capacitor with 50% value from induction motor resistance. The result shows that MERS has advantage and can keep the voltage in power grid when the voltage below 39% and 15% above rated voltage (220 Vrms) with the recovery time around 0.3 second and keep the dip voltage over 1 second.

Preliminary design of biomass fuel storage on a thermoelectric based biomass-electric energy conversion

Rural electrification in an archipelago country like Indonesia is a challenge. Indonesian government has stated that basic need of electricity is 60 kWh, however it is not easy to fulfill it. Fortunately, Indonesia is rich in biomass potency. Therefore, converting biomass energy to electricity might be a solution to the country electricity problem. A simple thermal energy harvesting system comprised of biomass burner and thermoelectric generator was investigated. Hot water storage was introduced to provide steady temperature. This paper specifically reported about the fuel storage mechanism of the proposed system. Two fuel storage mechanisms are investigated: integrated and bulk storage types. Integrated storage is a fuel storage facility that is included on energy harvesting device which useful in short-term operation, while bulk storage is located external of energy harvesting device which normally used for long-term operation. Based on the specification of pellet type, which is referred to EN 14961-1 standard, calculation shown that the largest volume of integrated fuel storage type for 168 hours of operation is 0.345 m3, while the bulk fuel storage type is 4.728 m3 for 6 months of operation.

Analysis of ferrite effect in Axial Flux Permanent Magnet Generator using magnetic circuit approach

In this paper, four models of AFPMG (Axial Flux Permanent Magnet Generator) are analyzed and compared to get the best model correspond to highest magnetic flux density that produced by those generators. Before analyzing performance of those models, leakage flux are modeled and analyzed by using magnetic circuit approach to defining the optimal distance of magnet to the magnet on the rotor disk. Therefore, optimal size of AFPMG are determined according to the optimal distance from magnet to magnet. The analysis results show that AFPMG with ferrite core and ferrite ring has the highest value of magnetic flux density. By the addition of ferrite material in AFPMG, it can increase the value of magnetic flux density. On the other hand, it is also can decrease leakage flux value. Analytical results then will be validated using finite-element method (FEM).

Analytical design of sea wave energy power plant using tubular linear PM generator in southern coast of Yogyakarta, Indonesia

In this paper, sea wave power plant was designed to be applied in southern coast of Yogyakarta, Indonesia. The plant was expected to generate 700 Wp output. It had two components: tubular linear permanent magnet generator (TLPMG) and floater buoy. The buoy and the ocean wave were assumed moving continuously. By this condition, the generator was then simulated using finite element software of FEMM. Analytical calculation was performed later, which shows that the generator could generate induced voltage and output power up to 68.243 Vp and 674.811 Wp respectively. Furthermore, the generator only generated power at certain times, due to different length between the wave magnitude and translation path of the translator.

Comparison of linear flux permanent magnet generator topologies by using FEMM 2D

Renewable energy becomes popular lately. It could make the better environment, especially for sea waves that could utilized 2% of world energy demand. Linear generator is one of the alternative method in energy harvesting, especially sea wave. Direct drive linear generator has some topologies, such as single stator — dual translator, and dual stator — single translator. The proposed design were 2 types of linear generator with halbach array permanent magnet, and radial permanent magnet, and ferrite cored with concentrated and slotted coil. The halbach array permanent magnet has the best magnet configuration in generating high flux density. Single translator — dual stator has the better voltage, and flux linkage. Thus the halbach array with single translator — dual stator has the best topology to generate high flux density, low cogging torque, low flux leakage, and the best quality of voltage.