Series-parallel Type Research Articles

Analysis of signature reliability of ring-shaped network system

PurposeThe purpose of this paper is to design a ring network topology system and alter it into a series–parallel type framework. Then, reliability of the framework is analysed and authors also discussed the signature to analyse the most sensitive component.Design/methodology/approachThis study presents a ring-shaped network system where this type of topology forms a single continuous pathway for signals through every node. In this study, a system consists of ring network topology is generalized in the series–parallel mixed configuration and reliability characteristics are evaluated with the assistance of universal generating function (UGF) technique. The system consists of wires, repeaters, components or computers and power supply. The wires and repeaters are in series, so, if they fail the whole system will fail and the signals will not go further. The components or computers are connected to each other in parallel configuration. So, the whole system will not fail until the last computer is working. There is also a two-unit power supply system which has one unit in a standby mode. On the failure of first power supply, the second one will start functioning and the whole system fails on the failure of both power supply.FindingsBy the assistance of UGF technique, reliability function of the framework is evaluated. Also, Barlow–Proschan index and expected lifetime for the designed system is estimated by considering a numerical example for the general ring-shaped network system.Originality/valueUGF technique is very effective for estimating the reliability of a system with complex structure and having two performance rates, i.e. completely failed and perfectly working, or more than two, i.e. multi-state performance. This technique enables to estimate every components contribution in the working and failure of the whole system. A general model of ring-shaped network system is taken and generalized algorithm is drawn for the system. Then a particular numerical example is solved for illustrating the use of this technique.

Synthesis and analysis of a cross-connected Fibonacci dc/dc converter with high voltage gain

For thermal energy harvester based on a step-up dc/dc converter, we present a cross-connected Fibonacci dc/dc converter and its analysis method in this paper. The topology of the proposed converter has three features: cross-connection of two Fibonacci-type converters, symmetrical design without smoothing capacitors, and inductor-less design by using switched-capacitor (SC) techniques. From these features, high stepped-up voltage which is expressed as a power of two is provided by the proposed converter. Unlike existing converters, the proposed converter achieves small internal resistance as well as small ripple factor, because the output voltage is supplied to an output load in all clock phases. Furthermore, the inductor-less design offers low electromagnetic interference (EMI) noise, small size, and light weight. As an example of the proposed converter, the performance of the proposed converter with 8× voltage gain was evaluated by theoretical analysis, SPICE simulations, and breadboard experiments. Compared with existing dc/dc converters, namely, Fibonacci type converter, series–parallel​ type, and charge pump, the proposed converter demonstrated high performance in the point of voltage gain, circuit size, power efficiency, and response speed.

An inductor-less universal switched-capacitor converter realizing dc/dc, ac/dc, dc/ac, and ac/ac conversion

For multi-applications, a novel universal switched-capacitor (SC) converter is proposed in this paper. The proposed converter consists of a rotation-type SC converter and a full-bridge circuit. Unlike the existing universal converter consisting of a series–parallel type converter and a full-bridge circuit, the rotation-type SC converter can offer an output voltage in all clock cycles by rotating the connection position of capacitors. Therefore, the proposed universal SC converter can achieve four types of conversion with high power efficiency, namely, step-up/step-down dc/dc conversion, step-down ac/dc conversion, step-up multilevel dc/ac conversion, and direct step-up/step-down ac/ac conversion. Through theoretical analysis, computer simulations, and bread board experiments, the characteristics of the proposed universal SC converter are evaluated. The result of these analyses demonstrates the feasibility of the proposed universal SC converter.

An inductor-less step-up/step-down multilevel inverter with a single input source

This paper presents a step-up/step-down multilevel inverter with a single input source. To achieve inductor-less design, the proposed multilevel inverter is designed by switched-capacitor (SC) techniques. In the proposed inverter, the voltage of series-connected main capacitors is averaged by shifting the connection of flying capacitors alternately. At the same time, a multilevel output is generated by connecting some of the series-connected main capacitors to an output terminal via transfer switches. Unlike existing SC multilevel inverters with a single input source, the proposed SC multilevel inverter can provide small component counts, step-up/step-down conversion, and flexible conversion ratio. Concerning the proposed SC 5-level inverter, theoretical analysis, simulation program with integrated circuit emphasis (SPICE) simulations, and breadboard experiments are conducted to investigate the circuit characteristics. The results of these analysis demonstrate that 1. The proposed inverter can achieve step-down conversion as well as step-up conversion by converting a single input voltage; 2. The proposed inverter can reduce three circuit components from the series–parallel type inverter; and 3. When the output power is 200W, the proposed inverter can achieve about 83% and 93% efficiency in the step-up mode and the step-down mode respectively.

自動車運搬船内電源用の非接触給電システム構成の検討

On ship carrying numerous cars, outlets cannot be used for car-storage locations owing to a danger of fire. Moreover, since the ceiling can be moved so that cars with different car height can be stored, the wiring of the cranes and power cable becomes very long. Under the circumstances, power supply for ship repair and maintenance is required. If such long cables are eliminated and electric power can be used even at the car storage location, it will be safe and convenient environment for ship repairing or maintenance of ship. This paper presents basic research on a configuration of wireless power transfer (WPT) system for power supply in ship by simulation and experiment. Investigated WPT system has two features. In use of the power supply, the receiving coil case can be freely attached to the transmitting coil case. Even existing equipment can be changed to WPT system by inserting to an outlet. The Investigated WPT system is a Series-Parallel (SP) type equipped with a capacitor connection switching circuit in which the output voltage control is performed in the receiving coil case. As a result of simulation and experiment, it was confirmed that WPT system enables to transmit power as a 1 kW class system without contact.

Study on efficiency of different topologies of magnetic coupled resonant wireless charging system

This paper analyses the relationship between the output power, the transmission efficiency and the frequency, load and coupling coefficient of the four kinds of magnetic coupled resonant wireless charging system topologies. Based on mutual inductance principle, four kinds of circuit models are established, and the expressions of output power and transmission efficiency of different structures are calculated. The difference between the two power characteristics and efficiency characteristics is compared by simulating the SS (series-series) and SP (series-parallel) type wireless charging systems. With the same parameters of circuit components, the SS structure is usually suitable for small load resistance. The SP structure can be applied to large load resistors, when the transmission efficiency of the system is required to keep high. If the operating frequency deviates from the system resonance frequency, the SS type system has higher transmission efficiency than the SP type system.

PHEV 시스템의 분석을 통한 신 PHEV 동력 시스템 제안

Abstract : In order to develop the PHEV(plug-in hybrid electric vehicle), the specific power transmission systems considering the PHEV system characteristics should be applied. A PHEV applied to series-parallel type hybrid power transmission system is a typical example. In this paper, the novel hybrid power systems are proposed by analyzing the existing PHEV system. The backward simulation program is developed to analyze the fuel efficiency of hybrid power system. Quasi-static models for each components such as engine, motor, battery and vehicle are included in the developed simulation program. To obtain an optimal condition for hybrid systems, an optimization approach called the dynamic programming is applied. The simulation is performed in various driving cycles. A weakness for the existing system is found through the simulation. To compensate for a discovered weakness, novel hybrid power systems are proposed by adding or moving the clutch to the existing system. Comparing the simulation results for each systems, the improved fuel efficiency for proposed systems are verified.

Patent analysis of hybrid vehicles: collaboration and technology leadership

Developments on hybrid vehicles have been growing during the last years due to the importance of green technologies. From a system engineering perspective a patent analysis of hybrid vehicles during 2000 to 2014 was developed to define a technology landscape of the recent years. A total of 40,023 patents were obtained and analyzed through two stages. During the first one the general areas of research and top patent companies were identified. Furthermore, an analysis of collaborations efforts was made. Results show that the company with the highest patent activity has also a strong focus on collaborative technology development. Toyota stands out for having the highest patenting rate and a diversity of collaboration agreements particularly on HEV technologies were identified. Subsequently, the main emphasis of research (according to international standard classifications) was defined. The analysis indicates that patent activity mainly focuses on control and electric vehicle propulsion; as well as in control systems especially adapted for hybrid vehicles. The second stage included the determination of the research focus according type of hybrid vehicle, the predominant alternative energy sources; and finally, the recent patents of top companies according to the most frequent alternative source of energy. The insights obtained indicate that research on parallel hybrid vehicle predominate, followed by series-hybrid and series-parallel hybrid type. In respect to alternative sources of energy, there is an extensive research on hydrogen, followed by solar energy. Toyota and Hyundai rank the first positions; its recent inventions on this arena were identified. The major contribution of this research is to determine a technological landscape on hybrid vehicles by means of an integration of collaborative systems engineering approach with patent analysis. Outcomes obtained aims to support the strategic decision process for organizations, companies, institutes and other stakeholders involved in this sector.

EDITORIAL NOTE VOL 4, NO 3 (2014)

JISIB continues to publish Case Studies. In addition we also publish in this issue Patents Analyses. Patent analyses can be read both as examples of how to perform such analyses, but may also find interest within specific industries. Professor Henri Dou, who is a founding father of this journal, was one of the pioneers in this area, also with the development of patent analyses software. We have also included a conceptual and theoretical paper. All of the contributions in this issue show that scientific work does not have to be limited to more narrowly defined empirical studies.The second paper by Salavdor et al. is dedicated to Associate Professor Jonas Rundquist, a colleague at Halmstad University and at the same time a great admirer of the Spanish speaking Americas, who passed away in December 2014. He will be greatly missed.The first article by Salvador and Léon is a patent analysis of the industry for hybrid vehicules. The paper shows that the company with the highest patent activity also has a strong focus on collaborative technology development. The analysis further shows that research on parallel hybrid vehicle predominate, followed by series-hybrid and series-parallel hybrid type. The findings support the strategic decision process for organizations, companies, institutes and other stakeholders involved in this sector. The analysis and procedure presented can be used for analyses in other industries.The second paper by Salador et al. is also a patent analysis, but this time for the Additive Manufacturing industry. Unlike the first paper this one identifies a number of trends through a keyword patent analysis. “The main areas of research are focused on shaping of plastics and after-treatment of shaped products and working metallic powder and manufacture articles from this material”. The leading countries on additive manufacturing research are United States, Great Britain and Switzerland.The third article by Vriens and Solberg Søilen is an attempt to show the implication of disruptive innovation on Intelligence Studies. It is a theoretical paper. Through a broad discussion of disruptive innovation theory the authors arrive at what they coin”Disruptive Intelligence”. In addition they describe ‘biases’ which may impair the production of ‘disruptive intelligence’.The Fourth article is a case study written by Calof. It is about how the National Research Council’s Technical Intelligence Unit work with intelligence. The study shows that intelligence users understood and could appreciate a combination of hard and soft intelligence type measures. A survey in the form of an intelligence evaluation instrument was developed to gather data for the paper.The last article by Avner is a case study about CI in the Israeli defense industry. It confirms previous assumption that the industry in general and especially in Israel is using CI intensively to support the decision making process.As always we would first of all like to thank the authors for their contributions to this issue of JISIB.On behalf of the Editorial Board,Sincerely Yours,Prof. Dr. Klaus Solberg SøilenEditor-in-chief

Design and Analysis of a Fibonacci Switched-Capacitor DC-AC Inverter

For small power applications, a Fibonacci switched-capacitor (SC) DC-AC inverter is proposed in this paper. Unlike common DC-AC inverter containing inductors or transformers, the proposed inverter requires no magnetic components. In the proposed inverter, bi-directional switches are controlled so that the voltage ratio of capacitors becomes the ratio of a Fibonacci number. By combining some of these capacitors in series, the proposed inverter generates a staircase AC waveform formed by many steps. Therefore, unlike the conventional SC DC-AC inverters based on a series-parallel type converter, the proposed inverter can provide the staircase AC waveform by a smaller number of capacitors. The theoretical analysis and simulation program with integrated circuit emphasis (SPICE) simulations show the effectiveness of the proposed inverter.

4륜구동 직렬형 하이브리드 전기추진시스템의 구성품 용량 최적화 연구

The study is conducted on the subject of optimization of components sizing for series hybrid electric propulsion systems. The components sizing of series type hybrid system is very important because each component of series type is larger than the corresponding component of the parallel type or series-parallel type. If the components sizing is greater or less than what is required to this system, the performance of the system is getting worse. The methodology for the sizing of a driving motor is introduced based on the foundation of determined system configuration and performance target. And the sizing of an engine/generator and a battery is achieved based on simulation results using Dynamic Programming. It is possible to find the optimal sizing of these components by comparing fuel efficiency of hybrid electric propulsion system for 8 driving cycles.

Kinetic investigation of dissolution of CaWO4 in oxalic acid solution

In this study, the effects of stirring speed, temperature, H2C2O4 concentration and particle size on the dissolution rate of CaWO4 in H2C2O4 solutions were investigated. CaWO4 was dissolved in H2C2O4 solutions as series parallel type reaction. In the first step which took place according to Langmuir-Hinshelwood Mechanism, H2C2O4 was adsorbed as a mobile adsorption layer on the surface of CaWO4, reacted to form adsorbed calcium aqua oxalato tungstate (Ca[WO3(C2O4)H2O]) intermediate product and the adsorbed Ca[WO3(C2O4)H2O] was desorbed into the solution. In the second step, Ca[WO3(C2O4)H2O] hydrolysed and formed H2WO4 which reacted with H2C2O4 to form hydrogen aqua oxalato tungstate (H2[WO3(C2O4)H2O]) as end product together with solid CaC2O4H2O. Model kinetic equations were derived which showed the relationships of the fractional conversion of CaWO4, the concentration of Ca[WO3(C2O4)H2O] and the concentration of H2[WO3(C2O4)H2O] with time. The diagrams drawn according to the model kinetic equations were in good agreement with the experimentally obtained diagrams (R2>0·99).Dans cette étude, on a examiné les effets de la vitesse d’agitation, de la température, de la concentration d’H2C2O4 et de la taille de particule sur la vitesse de dissolution de CaWO4 dans des solutions d’H2C2O4. On a dissous le CaWO4 dans des solutions d’H2C2O4 en une réaction de type série-parallèle. Dans la première étape, qui avait lieu d’après le Mécanisme de Langmuir-Hinshelwood, l’H2C2O4 était adsorbé en une couche mobile d’adsorption à la surface du CaWO4, réagissait pour former le produit intermédiaire adsorbé, aqua oxalato tungstate de calcium (Ca[WO3(C2O4)H2O]), et ce Ca[WO3(C2O4)H2O] adsorbé était désorbé dans la solution. Dans la seconde étape, le Ca[WO3(C2O4)H2O] était hydrolysé et formait l’H2WO4 qui réagissait avec l’H2C2O4 pour former de l’aqua oxalato tungstate d’hydrogène (H2[WO3(C2O4)H2O]) comme produit final avec le CaC2O4H2O solide. On a dérivé les équations cinétiques du modèle, lesquelles montraient les relations de la conversion fractionnelle du CaWO4, de la concentration de Ca[WO3(C2O4)H2O] et de la concentration d’H2[WO3(C2O4)H2O] en fonction du temps. Les diagrammes dessinés d’après les équations cinétiques du modèle étaient en bon accord avec les diagrammes obtenus expérimentalement (R2>0·99).

Research on DC Grid Power Characteristics and DC Active Power Filtering

When nonlinear load is powered by DC grid, harmonic currents and distortion power are produced. At first, the concept of the DC active power filter (DC-APF) is presented in this paper after the analysis of instantaneous power and power factor in the DC network. The DC-APF includes the parallel type, the series type and the series-parallel type, etc. The circuit topologies and the working principles of two kinds of DC-APF are proposed and analyzed: (1) the general type, which can compensate harmonic currents and reactive currents; (2) the correction type, which can track the DC voltage. The comprehensive simulation analysis of the double-bridge half-controlled DC-APF by means of MATLAB/SIMULINK and the experiment of the correction type prove the validity and the feasibility of these topologies and operating principles.

The Use of Oxalic Acid as a Chelating Agent in the Dissolution Reaction of Calcium Molybdate

In this study, the dissolution behavior of calcium molybdate (CaMoO4) was investigated in oxalic acid (H2C2O4) solution. The effects of stirring speed, temperature, H2C2O4 concentration, and particle size on the dissolution reaction of CaMoO4 were determined. The dissolved quantities of molybdenum and calcium were analyzed quantitatively by ICP-OES. Fractional conversion of CaMoO4 vs time and concentration of calcium vs time diagrams were plotted. It was observed that at constant temperatures and lower H2C2O4 concentrations, the dissolution increased by increasing H2C2O4 concentration, but at higher H2C2O4 concentrations, the effect of H2C2O4 concentrations was negligible. The dissolution reaction of CaMoO4 in H2C2O4 solution was performed in two steps as series–parallel type reaction. In the first step, CaMoO4 reacted with H2C2O4 to form the water-soluble calcium aqua oxalato molybdate (Ca[MoO3(C2O4)(H2O)]) intermediate chelate product. In the second step, the intermediate chelate, Ca[MoO3(C2O4)(H2O)], reacted with the reactant, H2C2O4, to yield water-soluble hydrogen oxalato dimolybdate chelate (H2[(MoO3)2(C2O4)]) and insoluble CaC2O4H2O as final products. It was found that 500 rpm was enough to eliminate the resistance of liquid film layer that surrounds the solid particles. It was concluded that the optimum temperature was 313 K (40 °C) and the optimum concentration of H2C2O4 was 1 kmol m−3 to obtain high conversion during the dissolution of CaMoO4.

The use of Langmuir–Hinshelwood mechanism to explain the kinetics of calcium molybdate leaching in oxalic acid solution

The effects of H2C2O4 concentration, temperature, stirring speed and particle size on the dissolution rate of synthetically prepared CaMoO4 were investigated. Dissolution of CaMoO4 in H2C2O4 solution took place as a series–parallel type reaction. In the first reaction step, which proceeded according to the “Langmuir–Hinshelwood mechanism”, calcium aqua oxalato molybdate (Ca[MoO3(C2O4)(H2O)]) was formed as a complex chelate intermediate product. In the second reaction step, together with insoluble CaC2O4H2O, soluble H2MoO4 was formed during the slow hydrolysis of Ca[MoO3(C2O4)(H2O)], and H2MoO4 reacted rapidly with H2C2O4 to form the water soluble hydrogen oxalato dimolybdate chelate (H2[(MoO3)2(C2O4)]). In the first step, the reaction rate was found to be first order with respect to H2C2O4 concentration at low concentrations while zero order at high concentrations. Activation energies were calculated for first and zero order reactions as 41.4 and 49.9 kJmol−1, respectively. A kinetic equation was derived that explains the relationship between fractional conversion of CaMoO4 and time. In the second step, the reaction rate was found to be first order with respect to H2C2O4 concentration and activation energy was calculated as 43.6 kJmol−1. Kinetic equations were derived that explain the relationship between the concentration of Ca[MoO3(C2O4)(H2O)] and time and the concentration of H2[(MoO3)2(C2O4)] and time. The diagrams plotted according to the model equations were in good agreement with the diagrams obtained experimentally where the protective behavior of CaC2O4H2O was not effective.

A kinetic approach to the esterification of maleic anhydride with methanol on H-Y zeolite

The purpose of this work is to study the kinetics of the esterification of maleic anhydride with methanol to form dimethyl maleate in a batch reactor in the presence of H-Y zeolite as a catalyst. This is a series-parallel type multiple reaction where, the first reaction involves the formation of monomethyl maleate that further reacts with alcohol to form dimethyl maleate. Dimethyl maleate was found to be the only product in the reaction mixture. Temperature, speed of agitation, catalyst size, reactant mole ratio and catalyst loading have pronounced effect on the rate of the reaction. A homogeneous rate model and heterogeneous rate models have been derived and fitted with the experimental data. The activation energy was found to be 44.65 kJ/mol.

High performance series-parallel type on-line UPS

An improved single-phase uninterruptible power supply (UPS) is proposed that is composed of a series converter and a parallel converter. The series converter regulates the output voltage, and then the parallel converter provides reactive current compensation and battery charging. A fast detection technique of the line voltage is proposed, which has almost zero transition time from the line power mode to the power failure mode. Furthermore, a current controller of the parallel converter for unity power factor is suggested and it is derived using the feedback linearization technique. A current limit technique in the power failure mode is proposed to protect the parallel converter without a system trip under any impulsive load. All control algorithms are implemented in software with a single-chip microcontroller. Experimental results obtained under a 3 kVA prototype show good transient and steady-state performance such as almost negligible transition time, 97% power efficiency and 99% power factor.

Design of a Charge-Average Type SC DC-DC Converter for Cellular Phones

A charge-average type DC-DC converter for cellular phones is proposed in this paper. The converter is designed by using switched-capacitor (SC) techniques. In the proposed power converter, the DC-DC conversion is performed by iterating the following processes. Firstly, an input voltage Vin is charged in capacitors which are connected in series. In this timing, an output voltage is taken out from arbitrary terminals of the capacitors. Next, the electric charges are equalized by connecting the capacitors in parallel. Therefore, different from conventional converters such as a series-parallel type converter and a Dickson-type converter, the proposed converter can provide stepped-down and stepped-up voltages which are expressed by (Q/P)×Vin (P ∈ {1, 2,..., N} and Q ∈ {1, 2,..., N}). Furthermore, the hardware cost for the proposed converter is smaller than that for the conventional SC power converters such as a ring-type converter and a series-parallel type converter. Concerning 3-stage power converters, SPICE simulations are performed to confirm the validity of the circuit design. For the input voltage 3.6 V, the power efficiency of the proposed circuit is about 90 % in the output current about 300 mA.

Design of a Step-Down Switched-Capacitor DC-DC Converter with Charge-Average Processes

A step-down DC-DC converter with charge-average processes is proposed in this paper. The converter is designed by using switched-capacitor (SC) techniques. Different from conventional converters such as a series-parallel type power converter and a Dickson-type power converter, the ripple noise of the proposed converter is small, because the output voltage is always obtained irrespective of the states of the clock pulses. The output voltage of the proposed converter is expressed by (Q/P) × Vin (P ∈{1, 2,..., N} and Q∈{1, 2,..., N}). Furthermore, when the number of the capacitors is small, the hardware-cost for the proposed circuit is less than that for the conventional converters such as a series-parallel type power converter and a ring-type power converter. Concerning 3-stage power converters, SPICE simulations are performed to confirm the validity of the circuit design. For the input voltage 3.6 V, the power efficiency of the proposed circuit is 92.7 % in the output current about 320 mA.

A Comparison of Resonant Converter Topologies with Three and Four Energy Storage Elements for Automatic Inductive Charging Application

The full-bridge series-resonant, parallel-resonant, series-parallel type SP-LLCC and parallel resonant type PRC-LLCC converters are compared for use in automatic inductive charging applications. Three order and four order models must be considered if, as in the case of this paper, the effect of magnetizing inductance and leakage inductance of the inductive coupler is considered. Analysis and breadboard results show that the series-parallel resonant converter type LLCC with capacitive output filter while maintaining excellent efficiency. A useful analysis technique based on steady-state analysis and first harmonic approach is also introduced. The topology selection criteria are based on the major application goal: minimum size, high switching frequency which is necessary to reduce the values of the reactive components, and high efficiency is needed to avoid thermal constraints.