S. Tapuchi

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Papers by S. Tapuchi

Straight hollow waveguide with three dielectric layers in the cross section

Journal of Electromagnetic Waves and Applications, 2016

Abstract The main objective is to understand the influence of the three dielectric layers (and no... more Abstract The main objective is to understand the influence of the three dielectric layers (and not only with one dielectric layer) and a metallic layer (Ag) in the cross section of the straight hollow waveguide on the output fields, output power density and output power transmission. The simplest and most efficient multilayer structure is a three dielectric layers that deposited on a metal layer. The contribution of the proposed technique to calculate the refractive indices and the transverse derivative of the dielectric profile for three dielectric layers is important to reduce the transmission losses of the dielectric-coated metal waveguides. This contribution is very important to improve the method that based on the mode model. This mode model can be a useful tool to predict the relevant parameters in the case of the hollow waveguide with three dielectric layers and a metallic layer (Ag) for practical applications (output fields, output power density and output power transmission), before carrying out experiments in the laboratory.

Input stage enhancement of a switched-capacitor switched inductor circuit

2012 IEEE 27th Convention of Electrical and Electronics Engineers in Israel, 2012

This paper proposed the enhance of the input stage of a switched-inductor switched capacitor DC-D... more This paper proposed the enhance of the input stage of a switched-inductor switched capacitor DC-DC converter. The inductors are charged in parallel from input voltage and discharged in series to the capacitor which are connected in parallel to each other, and then the capacitors are discharges in series to the load. Thus, the converter can achieve high step-up voltage gain which means high input currents. The number of switches in the input stage of this converter was reduced, reducing conduction losses and achieving a better efficiency. Mathematical analyses of the steady state operation and simulation results are presented. The simulations are according to the original circuit, 1kW output power, 700V output voltage and input voltage within the range from 70V to 120V.

$Research paper thumbnail of Directive fractal antenna for scanning applications$

Directive fractal antenna for scanning applications

2012 IEEE 27th Convention of Electrical and Electronics Engineers in Israel, 2012

ABSTRACT A Wideband, linearly polarized, microstrip antenna is presented. The antenna has two ele... more ABSTRACT A Wideband, linearly polarized, microstrip antenna is presented. The antenna has two elements connected to a series feeding network and excited by a coaxial connector. Each element is based on the fractal Koch snowflake. Among other advantages, the proposed antenna has the ability of elevation scanning as a function of frequency.

Unusual method for impedance evaluation of short dipole with arbitrarily mutual arms location and the implications for dc field sensors

Sensors and Actuators A: Physical, 2001

A relatively unknown analytical method is developed further in order to evaluate the capacitance ... more A relatively unknown analytical method is developed further in order to evaluate the capacitance between two long cylinders of equal length and diameter. The main approximation associated with the relatively unknown method was in assuming that the cylinders are uniformly charged no matter what is their length and diameter and no matter what is their mutual location and orientation. The

Steep conversion ration Ćuk, Zeta, and sepic converters based on a switched coupled-inductor cell

2008 IEEE Power Electronics Specialists Conference, 2008

ABSTRACT By replacing the input inductor of the Cuk (respectively Sepic, and Zeta) converter with... more ABSTRACT By replacing the input inductor of the Cuk (respectively Sepic, and Zeta) converter with a cell formed by a coupled inductor and one diode, a new family of converters with high voltage ratio is obtained. The energy accumulated in the leakage inductance is transferred to the load. The voltage stresses across the switching elements are kept at a moderate value. The reverse-recovery problem of the rectifier diode is alleviated. A DC analysis allows for the formulation of the DC gain as a function of the turns ratio and coupling coefficient of the coupled inductor, as well of the load. Experimental results confirm the theoretical expectations.

Novel DC-AC inverter based on buck converter

2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2016

The paper proposes an original DC-AC inverter that is based on combination of buck converter with... more The paper proposes an original DC-AC inverter that is based on combination of buck converter with standard three-level H-bridge inverter. This inverter uses simple feed-forward control in order to obtain almost sinusoidal output currents and voltages. The first advantage of the proposed inverter over standard inverter topologies is simple structure with less components such as switches, capacitors and DC sources. The second advantage is simple control there is no need in capacitors' voltage balancing or closed loop control. The third advantage is almost sinosoidal output voltages and currents with very low Total Harmonic Distortion Factor (THD). This inverter can be used in low power applications and also in high power applications instead of complicated multilevel inverters. The proposed inverter was analyzed by extensive simulation results. Several aspects as THD of the inverter output currents, and voltages, harmonic content, frequency spectrum distribution are studied. Moreover, the proposed inverter was experimentally tested. The simulation and experimental results were compared and they verify the proper operation of the proposed inverter.

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New Control Strategies for IGBT Based Bridge Type SFCL

2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC), 2018

This paper presents IGBT based bridge type SFCL. The paper proposes two different control strateg... more This paper presents IGBT based bridge type SFCL. The paper proposes two different control strategies for short circuit current limiting optimization. Extensive simulations validate the proposed strategies. The simulation results are discussed and compared to the conventional thyristors topology control method. The advantages and disadvantages of each strategy are discussed. The conclusions are presented at the end of the paper.

Novel Electromagnetic Method for Underground Tunnels Detection

2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC), 2018

This paper proposes a new system for detection of underground tunnels. The proposed system is bas... more This paper proposes a new system for detection of underground tunnels. The proposed system is based on underground installed coil, which is supplied by AC current source. The coil radiates magnetic field in the underground space. This magnetic field is deformed when iron or metal objects are present in the underground space. These distortions are measured by pick up coil and filtered by electronic unit. By identification of distortions the presence of underground metal and iron object are identified. The system was validated by extensive experiments that show that the proposed system successfully identifies underground objects.

Novel system for underground tunnels detection

2017 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2017

This paper proposes a new approach for detection of underground tunnels. The proposed system is a... more This paper proposes a new approach for detection of underground tunnels. The proposed system is able to detect stationary and moving underground metal objects and as a result to detect tunnels. The detection system is implemented by underground installing of two parallel rows of electrically conductive rods. These rods are electrically isolated and exposed only at the lower edges. AC current is supplied to the rods and creates magnetic field in the metal object that is located underground between the rows of rods. In order to sense the magnetic fields around the objects, pick-up-coil magnetic field sensors are deployed between the rods lines. The object's magnetic field induces voltage in pick-up-coil sensors.

Smart grid communication technologies- overview, research challenges and opportunities

2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2016

The smart grid a new generation of standard power distribution grid. The communication infrastruc... more The smart grid a new generation of standard power distribution grid. The communication infrastructure is critical for the successful operation of the modern smart grids. The use of communication technologies ensures the reduction of energy consumption, optimal operation of the smart grid and coordination between all smart grids' components from generation to the end users. This paper presents an overview of existing communication technologies such as ZigBee, WLAN, cellular communication, WiMAX, Power Line Communication (PLC), their implementation in smart grids, advantages and disadvantages. Moreover, the paper shows comparison of communication infrastructure between the legacy grid and the smart grid and smart grid communication standards. The paper also presents research challenges and future trends in communication systems for smart grid application.

Novel optimized method for maximum power point tracking in PV systems using Fractional Open Circuit Voltage technique

2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2016

The paper proposes new improved MPPT measurement method based on the conventional Fractional Open... more The paper proposes new improved MPPT measurement method based on the conventional Fractional Open Circuit Voltage (FOCV) method, where the maximum power point voltage is estimated by continuous measuring of PV panel's open circuit voltage and calculation of the voltage factor. In the proposed Semi-Pilot Cell (SPC-FOCV) the measurements of the open circuit voltage are performed on one PV cell which is located at the edge of PV panel. When there is no measurement of the open circuit voltage, the PV panel configuration is unchanged and all PV cells inside the panel supply power to the load. During the measurement, the semi-pilot cell is disconnected from the panel by a pair of transistors and bypassed by the bypass diode in order to ensure proper operation of other cells in the panel. This method is intended for application in small PV systems. The proposed method was analyzed and validated by extensive simulation results. It was proved that it can precisely estimate maximum power point voltage. The SPC-FOCV method overcomes the disadvantages of the conventional FOCV and pilot cell FOCV methods. By implementing the proposed method, more power can be supplied to the load with higher efficiency than by the conventional FOCV and pilot cell methods.

Novel Segmentation Algorithm for Maximum Power Point Tracking in PV Systems Under Partial Shading Conditions

2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC), 2018

The paper proposes new MPPT Segmentation method for partial shading conditions. The proposed meth... more The paper proposes new MPPT Segmentation method for partial shading conditions. The proposed method is based on principle of division of the power-voltage curve into uniform segments and location of global maximum power point inside the chosen segment. In order to validate the algorithm, it was tested under different shading condition and with different PV systems. The simulation results show that the Segmentation algorithm precisely identifies the highest MPP on the power-voltage curve. The Segmentation algorithm was compared with standard P&O and also with other MPPT algorithms for partial shading conditions. This comparison showed that Segmentation algorithm provides better results and insures higher output power of the PV system than standard P&O and also with other MPPT algorithms. Simulation results also show that Segmentation algorithm works faster than P&O.

Mössbauer and magnetization studies of some neptunium heavy-electron intermetallics

Physical Review B, 1987

Mossbauer studies of the heavy-electron magnet NpBel3 and new data on the compounds NpRu2, NpOs2,... more Mossbauer studies of the heavy-electron magnet NpBel3 and new data on the compounds NpRu2, NpOs2, and NpIr2 are reported. Whereas NpRu2 remains paramagnetic to lowest temperatures, the three other materials exhibit long-range magnetic order which, however, is very sensitive to defects and strain and may easily be suppressed. A correlation between isomer shift and electronic specific heat is presented.

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Analysis of hybrid thirteen level cascaded H-bridge inverter operated under different PWM methods

2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), 2015

The paper presents an extended analysis of a hybrid 13-level inverter operated under different mo... more The paper presents an extended analysis of a hybrid 13-level inverter operated under different modulation methods and different conditions. The proposed approach can be extended to any desired number of levels. Extensive simulation results of the proposed inverter are presented. The simulations are validated by hardware-in-the-loop experimental results.

Boundary controller for switched capacitor converters

2014 IEEE 28th Convention of Electrical & Electronics Engineers in Israel (IEEEI), 2014

A boundary controller to switched capacitor circuit is proposed. Conventional average output volt... more A boundary controller to switched capacitor circuit is proposed. Conventional average output voltage control usually leaves the voltage ripple uncontrolled. The proposed controller keeps the ripple between two desired bounds allowing connecting a smaller output capacitor. Moreover, it can solve the start up or other non-steady states problems. Simulation results are presented to validate the theoretical analysis.

New capacitive synchronous AC machine

2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), 2015

The paper proposes a new type of the synchronous AC machine operated on a principle of the electr... more The paper proposes a new type of the synchronous AC machine operated on a principle of the electric field effect. The proposed machine has smaller size and lighter weight than the standard electromagnetic synchronous machines with the same rated parameters. Another important advantage is a simple structure of the machine, which simplifies the production process and reduces the costs of the motor. The paper also presents extensive simulation results of the proposed capacitive machine. The simulation results show that the proposed machine has high industrial potential and able to develop relatively high power output.

Phase shifted PWM with third harmonic injection for over-modulation range operation

2014 International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 2014

ABSTRACT

Mitigation of Mobile Radio Parasitic Radiation Effects: A Review

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Wind turbine performance index

2012 IEEE 27th Convention of Electrical and Electronics Engineers in Israel, 2012

ABSTRACT

Straight hollow waveguide with three dielectric layers in the cross section

Journal of Electromagnetic Waves and Applications, 2016

Input stage enhancement of a switched-capacitor switched inductor circuit

2012 IEEE 27th Convention of Electrical and Electronics Engineers in Israel, 2012

$Research paper thumbnail of Directive fractal antenna for scanning applications$

Directive fractal antenna for scanning applications

2012 IEEE 27th Convention of Electrical and Electronics Engineers in Israel, 2012

Unusual method for impedance evaluation of short dipole with arbitrarily mutual arms location and the implications for dc field sensors

Sensors and Actuators A: Physical, 2001

Steep conversion ration Ćuk, Zeta, and sepic converters based on a switched coupled-inductor cell

2008 IEEE Power Electronics Specialists Conference, 2008

Novel DC-AC inverter based on buck converter

2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2016

バックコンバータに基づく新しいDC-ACインバータ【Powered by NICT】

New Control Strategies for IGBT Based Bridge Type SFCL

2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC), 2018

Novel Electromagnetic Method for Underground Tunnels Detection

2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC), 2018

Novel system for underground tunnels detection

2017 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2017

Smart grid communication technologies- overview, research challenges and opportunities

2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2016

Novel optimized method for maximum power point tracking in PV systems using Fractional Open Circuit Voltage technique

2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), 2016

Novel Segmentation Algorithm for Maximum Power Point Tracking in PV Systems Under Partial Shading Conditions

2018 IEEE 18th International Power Electronics and Motion Control Conference (PEMC), 2018

Mössbauer and magnetization studies of some neptunium heavy-electron intermetallics

Physical Review B, 1987

Download

Analysis of hybrid thirteen level cascaded H-bridge inverter operated under different PWM methods

2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), 2015

Boundary controller for switched capacitor converters

2014 IEEE 28th Convention of Electrical & Electronics Engineers in Israel (IEEEI), 2014

New capacitive synchronous AC machine

2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe), 2015

Phase shifted PWM with third harmonic injection for over-modulation range operation

2014 International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 2014

ABSTRACT

Mitigation of Mobile Radio Parasitic Radiation Effects: A Review

Download

Wind turbine performance index

2012 IEEE 27th Convention of Electrical and Electronics Engineers in Israel, 2012

ABSTRACT

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