The decentralization might be the mega trend toward the new social system for the next century. Especially, reorganization of the electricity business, first initiated in the UK 1989, has acceleratedly unfolded globally and trust into the stage of retailing competition in the UK and the US. In this paper, decentralization of electricity business around the world are surveyed. Further, rule-making among market players and technical requirements at open electricity market are touched on.

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In this paper, a new dc-dc converter topology to obtain wide control range of output voltage and higher efficiency is proposed. In this new dc-dc converter, a boost-mode and buck-mode dc-dc converters having a common dc-inductor, a common dc-capacitor and a common load are connected in parallel. Thus, the dc-inductor current flows only the buck-converter part or the boost-converter part, and losses produced by the switches and current stresses for the switches and diodes are both less than those of the previously proposed boost and buck cascaded dc-dc converter. The circuit topology and principle of converter operation are introduced. Then, application of this new dc-dc converter to single-phase PFC rectifier, including modulation and control techniques are discussed. Finally, experimental results of the new PFC rectifier are shown to confirm the validity of the theory and usefulness of the proposed converter in practice.

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Simulation technique is quite effective for the most optimized design of an induction-heated(IH) cooking appliance in which both electromagnetic field and thermal flow require to be controled. We developed the system of nonliner analysis for electromagnetic field and thermalfluid by finite element method. By this system it is possible to simulate the behavior of electromagnetic field which causes induced currents and the behavior of thermal fluid simultaneously. This paper presents the results of performance evaluation for the new IH rice cooker as one of the applications of this system.

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Recently, it is often observed that the harmonics interference occurs in the AC power line because switching mode inverter and converter have been widely used as power supplies of the electronic and electrical equipment. In order to prevent this harmonics interference, the guideline on the maximum limits of the harmonics distortion factor of the input current was indicated.
In this paper, we propose a modified boost chopper that has two switching devices. The behavior of the circuit is analyzed and experimental results will be shown. The experimental results show that the circuit decreases the harmonic distortion of the input current like a conventional active smoothing filter. And we show that these two switching devices can be used not only as switches of the modified boost chopper but also as switches of a half-bridge type inverter for the electronic ballast of fluorescent lamps. As a result, it is revealed that the harmonic distortion of the input current obtained by the proposed inverter satisfies the maximum limit of IEC 1000-3-2 class C sufficiently. And the inverter realized the high power factor of 0.99

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This paper presents performance evaluations of Auxiliary Resonant Commutation Snubber-linked (ARCS) three phase voltage source soft switching inverter using IGBTs which can operate under a condition of Zero Voltage Switching (ZVS). This inverter system with the two input and two output optimal type I digital servo controller is more suitable for high power applications compared with resonant DC linked soft switching inverter. The system performances of this inverter are illustrated and evaluated from an experimental point of view.

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Recently, a friendly and an energy saving air conditioners are in great demand. Therefore, an hermetic motor compressor (IPM type) was developed and its high efficiency is realized by an appropriate control method of the motor current vector and a sine wave PWM inverter. This paper presents the control method the current phase in maximum efficient condition and the IPM efficiency when it is driven by a sine wave PWM inverter.

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The immittance converter has an input impedance that is proportional to the admittance of loads connected across output terminals. Therefore, in this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, it converts a constant voltage source into a constant current source and a constant current source into a constant voltage source.
It is well known that the quarter-wavelength transmission line shows immittance conversion characteristics. However, it has very long line length for its switching frequency, and is not suitable for power electronics application. So we proposed five types of immittance converters that consist of lumped elements L, C and show improved immittance conversion characteristics at a resonant frequency.
The efficiency of an immittance converter is the most important parameter when it is used in practical applications in a high frequency link. In this paper we show voltagecurrent transformation characteristics and efficiency characteristics of T-LCL and π-CLC types immittance converters which consist of L, C elements with losses. These were determined analytically and experimentally.

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SMR or Switched Mode Rectifier is usually controlled by an analogue circuit, however, in this paper it is reported that Buck-Boost type SMR operated at the fixed switching frequency and CCM or Continuous Current Mode was controlled by a microprocessor using following new techniques. The “two section-paired method” was newly adopted to controlled the reactor current between upper and lower sinusoidal target curves satisfying the limitation imposed by operation at fixed frequency. And also the “delta Ip constant method” was introduced to keep CCM under the wide load conditions, however, at a light load condition, the current mode changed to DCM or discontinuous current mode, which were simulated by P-spice showing the constant DC output voltage characteristics.

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Using an inverter is a highly effective method of achieving the low power consumption required to reduce the environmental impact of electronic devices. Toshiba has developed a high voltage dielectric isolation IC process that will become a key component of future inverters. The new process realizes 500V blocking with a construction that uses a silicon on insulator (SQI) wafer with 16um silicon layer and 4um buried oxide film. This was accomplished using Toshiba's original silicon wafer direct bonding technology and deep trench isolation technology. This process technology has been used to developed the TPD4005K high voltage pulse width modulation DC brush less motor driver.

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In this paper, a novel maximum power point tracking (MPPT) scheme is proposed and simulated using a high-frequency AC link converter with secondary side PWM control scheme. Having an eye on that the maximum voltage point of solar cell is in proportion to its panel temperature (Tsc), with operating the power converter whose operating point keeps its input voltage maintaining the maximum voltage point, the maximum power point becomes tenderly possible to be tracked. As the results of that, we got the hopeful answer to apply to practical field, furthermore the secondary phase-shift PWM control DC-AC converter is not only properly fulfilled in EMTDC where to generate signal α is not done in Draft Module, but shows us a special quality to apply for a solar generation system.

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