Economic Evaluation of Power System Flexibility by Commercial Air Conditioner Control with Large Penetration of Photovoltaic Generation

High penetration of intermittent renewable energy such as photovoltaic (PV) and wind power could cause shortage of power system flexibility. Demand response is expected to help supply ancillary service instead of the conventional power plant. Commercial air conditioners are a promising responsive load for demand response because they account for a large proportion of power consumption in the power system. We calculate a system operation cost and hourly operation pattern of each power plant by using the optimal power generation model considering flexibility supply from controlling commercial air conditioner. We obtained the following results as an effect of commercial air conditioner control. (1) The power generation of oil fired power plants decreases at peak time and annual fuel cost of oil fired plant is reduced by approximately 30% at most in Kanto area. (2) The percentage of rated operation mode of LNG combined cycle plants increases. (3) Curtailed energy rate of PV decreases because a power storage amount by pumped hydropower generation increases. (4) Required battery capacity to reduce PV curtailed amount decreased by combining battery energy storage system in case of high penetration of PV.     

Search method for the matrix multiplier time constant and the weighting matrix of the multivariable Popov stability criterion

The multivariable Popov stability criterion contains two arbitrary diagonal matrices which are called the weighting matrix and the multiplier time constant matrix. The choice of the matrices determines the sharpness of the stability criterion obtained. In this paper, a method of searching for adequate values of the matrices is proposed. The method is based on the relation between the M-matrix and the positive-definite hermilian matrix. Numerical examples show that this method is useful in obtaining a sharper stability condition.     

Proposal and Feasibility Study of the Integrated Diode Synchronous Motor

This paper presents a new type of magnet‐free motor that has concentrated stator windings and rotor coils with a pair of diodes. The most important feature of this motor is that currents in the rotor coils can be generated by utilizing the changes in the spatial second harmonic of the magnetic fields due to the concentrated stator windings, which normally increase motor losses. A prototype of the motor was designed and fabricated, and its basic performance was evaluated. First, using simplified analytic models, we explain the mechanism of inducing currents in the rotor coils by the changes in the spatial second harmonic of the magnetic fields. Second, we compare the torque performance of the proposed motor and that of other types of motors including a magnet motor through finite‐element analyses. The analyzed data show that the proposed motor can possess greater torque/volume ratio than that of the other motors. Finally, using the measured data, we validate the mechanism of inducing currents in the rotor coils, and examine the torque and power characteristics of the motor.     

日本POLA艺术博物馆的隔震结构和玻璃天窗

本文具体介绍了建造在自然环境中的POLA艺术博物馆的结构设计概要。为了满足艺术珍藏品在地震时不至损坏的博物馆特有的技术要求,保护地震时人命安全,结构设计时对这座几乎建造于地下的建筑采用了基底隔震系统,而且在上部结构的底部采用了立体大跨度桁架系统,更有效合理地实现了基底隔震系统的隔震性能。隔震系统和大跨度桁架系统的结合统一,既实现了优美的建筑设计要求,又确保了结构在大地震下的高度抗震性能。     

Charge and Discharge Control to Save Regeneration Energy for Overhead Line and Energy Storage Device Hybrid Power Source Three‐Level Inverter

Hybrid power source three‐level inverter is proposed as a main circuit system with energy storage device for increasing regenerative power. This paper proposes a charge and discharge control method to utilize the regenerated energy. The proposed method is verified by experimental tests with a scaled‐down model and numerical simulation.     

High Power Neutral Beam Injection in LHD

The results on high power injection with the ueutral bean, injection （NBI） system for the Large Helical Device （LHD） are reported. The system consists of three beam-lines with two hydrogen negative ion （H^- ion） sources installed in each beam-line. In order to improve the injection power, a new beam accelerator with a multi-slot grounded grid （MSGG） has been developed and applied to one beam-line. Using the accelerator, a maximum power of 5.7 MW was achieved in 2003 and 2004, and the maximum energy of 189 keV was reached. The power and energy exceeded the design values of the individual beam-line for LHD. The other beam-lines also increased their injection power up to about 4 MW, and the total injection power of 13.1 MW was achieved with three beam-llnes in 2003. Although the accelerator had an advantage in high power beam injection, extracted beams expand in the short side direction of the ground-grid slot. The disadvantage has been resolved by modifying the aperture shapes of the steering grid.     

Odor Components of Human Breath After the Ingestion of Grated Raw Garlic

The major odor components of finely grated, raw garlic in the air of the human mouth have been studied. Immediately after garlic ingestion, tests of the mouth air of six subjects revealed two major peaks that were positively identified as being allyl mercaptan and diallyl disulfide; these findings are based on an evaluation of the fragment patterns of a GC-MS analysis and from the actual retention times of these authentic compounds. The allyl mercaptan level was higher than the level of diallyl disulfide, although both compounds smell like garlic. Our results suggest that after garlic ingestion, allyl mercaptan is the major garlic-smelling compound in human mouth air, and diallyl disulfide is secondary.     

A Power Control Method to Save Energy for Wayside Energy Storage Systems in dc‐Electrified Railway System

The introduction of wayside energy storage systems is effective for the recovery of regenerative brake energy in dc‐electrified railways. However, considering the cost of their deployment, it is preferable to maximize the energy saving effect with a minimum capacity of the energy storage devices (ESDs). In this paper, we propose a power control method that can improve the energy saving effect while managing the energy of the ESDs. The proposed method is implemented by controlling the filter capacitor voltage of the line side of the power converter for the ESDs depending on their energy and the line voltage of the overhead contact line to which they are connected. Next, the proposed method is verified by numerical simulations and experimental tests with a 1 kW class downsized model.