1) Power Electronic Technologies will be more important for the next generation of automobiles. 2) Hybrid technology is a core technology for the evolution of the ultimate eco-car, because it reduces CO2 emissions so greatly. As hybrid vehicles become popular, even more semiconductors will be required in the near future. 3) Great expectations are held for the SiC-Inverter. 4) Toyota's in-house development technology is an essential resource for Toyota's strength.
“The allover method” using induction heating and thermoplastic adhesive is the effective dismantlable adhesion method for interior constructions, because of the advantage to facilitate recycling, reduce a sick house syndrome and easy work. Authors are studying on the new heating coil for adhesion and dismantling at the constructions. This paper describes a linear induction coil with traveling magnetic field for long structures.
For small capacity rectifier circuits such as those for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. In a certain application, it is necessary to obtain the lower output voltage, that is very difficult to realize such condition by using the passive elements only. In order to realize such condition, we propose a power factor correction scheme using a cycle-control and phase-control without high frequency switching devices. In this method of cycle control, improved input current wave can be obtained by widening conduction period. Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The results are confirmed by the theoretical and experimental implementations.
A novel zero current switching (ZCS) dual full bridge dc-dc converter and power conditioning system (PCS) for fuel cell system adopts the proposed dc-dc converter are presented. An experimental implementation shows the efficiency of the proposed converter higher than 98% at maximum. Prototypes of PCS also obtained high conversion efficiency at low voltage and high current dc input operation of fuel cell.
The boost rectifier has wide utility owing to its usefulness for efficient operation. The single-phase discontinuous-conduction-mode (DCM) boost rectifiers are utilized with very simple control scheme for lower power applications. However, the DCM boost rectifier produces large harmonic-distortion of the input-current in lower output-voltage range. To overcome the problem, the author proposes a new control method for the input-current waveform on the single-phase boost rectifier applying pulse space modulation (PSM). The proposed control method, the space (area) or time-integral-value of the inductor- or the input-current in each modulation period is controlled, directory. Therefore, the single-phase boost rectifier realizes high quality input-current waveform with very simple algorithm.
In this paper, the circuit of high frequency power supply for the electrode-less discharge lamp is proposed. In order to obtain the high power, the circuit is made by combining outputs of parallel four 125W power conversion circuits. This method is effective in order to make the high power circuit with the low cost in small space. The design of 500W-class high frequency power supply for electrode-less discharge lamp with 2.6MHz is reported. The electric power transmission from the power supply to the load carried out using coaxial cable. The control circuit for operating the lighting equipment in the high reliability is also reported.
We have developed a high efficiency, low noise Rotary compressor with a concentrated winding motor in order to meet energy saving and noise reduction demands for refrigeration and air conditioning equipment. In order to reduce the noise, we conducted a magnetic field analysis and a modal analysis. The results of those analyses showed that the noise was caused by the resonance between the magnetic force of the radial direction components of a concentrated winding motor and the natural frequency of first bending mode of the rotor-crankshaft. Furthermore, it was found that inhibiting the eccentricity between the rotor rotation axis and the stator core is effective in reducing the magnetic force. An experiment was conducted to verify the results of the analyses and a reduction in the noise of the compressor was confirmed.
In the wave power generation, the generator is driven with the air turbine which is moved by wave power. However, this method has the disadvantages that the equipment becomes huge, and the cost is high. Recently, the linear synchronous generator begins to research. In this paper, the relationship between the pole pitch and the loss of linear synchronous generator is investigated for wave power generation.
This paper examines iron losses prediction approach for switched reluctance motor. It is well known that the flux density distribution in core of SRM is intermittent triangular rather than continuous sinusoidal waveform different from conventional AC machines. The approach examined in this paper obtains the flux density distribution in the segmented core by employing 2D-FEA. Then, harmonic analysis based on Discrete Fourier Transform for the obtained flux density distribution provides flux density amplitudes for respective frequencies. Finally, the sum of iron loss in each segmented core can be calculated from Steinmetz equation as the total iron loss of machine. The comparative studies using a 4-phase switched reluctance servomotor shows that the calculated iron loss is good agreement with the measured one in spite of operating points.
This paper proposes a new approach to the individual-phase non-active current compensator under the non-sinusoidal and unbalanced conditions using the correlation function. Only the component of the load side current correlative to the source voltage waveform is detected, then the residual components are compensated on the source side. So the source current becomes sinusoidal with unity power factor with the unbalanced conditions. The basic principle of the proposed compensation method is discussed in detail. Digital computer simulation is implemented to verify the validity of the proposed compensation method. Digital computer simulation results demonstrate that the source current becomes sinusoidal with unity power factor, but the source currents remain unbalanced when the proposed non-active current compensation method is applied.
In this paper, a novel H-bridge multi-cell inverter system for energy storage will be proposed. A large capacity 100MW SMES system and a smaller 10MW system which is the experimental model of the 100MW system have been designed and evaluated. These systems handle active power and also reactive power. During the simulation study of these systems, presence of unstable phenomena of the d. c. voltage of the cells have emerged. In this paper, the contents of the trial design, the causes and characteristics of the unstable phenomena and solutions will be presented.
Photovoltaic generation systems for residential houses have been rapidly spread in recent years. This paper describes the battery combined photovoltaic generation system for disaster-proof house. The system consists of photovoltaic modules, power conditioner, lead-acid batteries, commercial line/independent output switch unit and receiving power detection unit. This system uses inexpensive nighttime electricity for daytime demand with photovoltaic generated power.
Korea is the foreign country that is the nearest to Japan. However, there are a few opportunities knowing the fact unexpectedly. The market which is different from Japan is formed by a difference of a habit/appetite culture. It is a very interesting market. Therefore I introduce a refrigerator in Korea and the market and technology of inverter.
This paper describes that Si power devices has remarkably made progress of power electronics since 1960s, but the operational junction temperature of Si power devices do not generally make progress for 40 years, and the improvement of switching frequency of Si power devices do not expect in feature. And this paper shows the effect of replacement of Si power device with SiC power devices. Furthermore this paper shows that in 21st century electric energy storage system with long life and high cost-performances is required. One of the desirable electrical energy storage devices is EDLC (Electric Double Layer Capacitor). This paper shows recent technical information of the EDLC.
This paper proposes a novel single-phase to three-phase converter topology, which aims at the source side power ripple. Source side energy provides directly to the motor without smoothing at the power converter. The proposed system obtains unity power factor of the converter without a reactor and a bulky electrolytic capacitor. The proposed power flow method applies to two power converters. One is an ac-dc-ac circuit topology, which has a diode rectifier and a three-phase inverter. The other is a single-phase to three-phase matrix converter. This paper proposes an inverter control method to obtain both the unity power factor operation and variable speed motor drive. Furthermore, the proposed control method applies to the matrix converter using an algebraic transfer matrix. This paper describes that the proposed method achieves the unity power factor operation by experimental tests. The experimental results confirm the feasibility of the proposed method.
A high performance voltage detection and PLL system suitable for single-phase inverters such as UPS will be proposed. The single-phase utility voltage is transformed to a pseudo three-phase voltage, and this three-phase voltage is used for the voltage detection and the phase detection. The time delay of the circuit to obtain the three-phase signal is only 4.6 msec (in case of 60Hz), therefore this method can be used for three-phase SVG to reduce the influence of unbalanced system voltage disturbances such as 2LS.
In recent year, with increasing concern about global environmental protection, producing natural free energy resources has been a focus of constant attention. Especially, the solar photovoltaic (PV) power energy became widely used over the last decade. As for the grid interactive inverter, higher conversion efficiency is further required. This paper presents a design consideration for current resonant converter, which is equipped for string power conditioner to improve its conversion efficiency. We have developed a higher efficiency prototype power conditioner and 94% as the maximum conversion efficiency was obtained at 3kW output.
An interior permanent magnet synchronous motor (IPMSM) operates by two kinds of torque mechanism, just as the magnet torque and the reluctance torque, and has compact size and high efficiency. Recently, you can see increasing demand for the low-profile interior permanent magnet motor set in the hybrid electric vehicle (HEV). An axial-flux type interior permanent magnet synchronous motor (AIPMSM) is proposed as one of low-profile interior permanent magnet motors. This paper reports inspection of optimal structure for thining by use of finite element method.
Permanent magnet is used for various equipments. In order to improve the performance of equipment, high remanent magnetic flux density and high coercivity are required for a permanent magnet. This paper presents a trend of Nd-Fe-B magnet and its application to the high field magnetic circuit.