Study on Power Fluctuation Dispatch and Capacity Design of Short Period Power Fluctuation Compensation System in Consideration of Power Loss

Since the output of photovoltaic (PV) generation includes power fluctuations caused by natural conditions, the installation of PV on a large scale is expected to affect load frequency control of the power grid. One method of compensating power fluctuations is the use of energy storage (ES), such as batteries and capacitors. A power fluctuation compensation system composed of an electrical double layer capacitor energy storage system (ESS) and a Li‐ion battery energy storage system is considered. The power loss characteristics of both ESSs during power fluctuation compensation are modeled by equivalent circuits based on ES impedance spectra. The models are validated by experiments simulating power fluctuation compensation. Using these ES models, simulations were carried out to determine the power fluctuation dispatch method between the two ESSs and the capacity of the ESSs in consideration of power loss minimization.     

Single-crystal growth of a new sodium molybdenum bronze Na0.86Mo5O14

Abstracts are not published in this journal     

Antimicrobial Effects of Pressured Carbon Dioxide in a Continuous Flow System

The application of microbubbles of pressured CO₂ greatly increased CO₂ concentration in the solution treated. By treatment at 6 MPa, 35°C and average residence time 15 min, L. brevis was completely inactivated at the level of dissolved CO₂,γ≧ 11 (γ, Kuenen's gas absorption coefficient). E. coli and S. cerevisiae required γ≧ 17, and T. versatilis required γ≧ 21 for complete inactivation. Z. rouxii could be sterilized at 20 MPa and 26. A comparison of the continuous and batch method showed that L. brevis was inactivated completely under pressured CO₂ > 0.16 g/cm³ with the continuous method and >0.9 g/cm³ with the batch method.     

Selection of inspector for visual inspection

This paper presents a statistical method for selecting the best inspector for visual inspection having the highest defect-finding ability among k(≥2) prospective inspectors.

A sample containing known number of defects are submitted to each of k prospective inspectors. As the sample size is increased, sampling variation decreases so that we have a better chance of selecting the truly best inspector, but at the same time the cost of sampling is also increased, The problem is how to determine the sample size required for selecting the best inspector with specified probability P*.

This problem is formulated from the indifference zone point of view with an application of the loss function which takes into consideration the opportunity cost of making a wrong selection and the cost of sampling. Minimax solution is obtained under the restriction that the best inspector is to be selected with the specified probability P*. The selection procedure is applied to the visual inspection of car body painting.     

Experimental Services of Energy Management for Energy Users in Business Region on Miyakojima City All‐Islands EMS Demonstration Project

Smart grid and demand response (DR) had been attracting attention and evaluated in several demonstration projects. Many DR experimental results for residential and large‐scale buildings had been evaluated, while evaluation for small size buildings seems to be not enough. In this paper, a new energy service combined EMS method is proposed for small size buildings. Then results of its application to Miyako Island All‐Islands EMS Demonstration Project are introduced. The experimental services include not only DRs but also peak cutting recommendations and energy analysis reports. The results show combination of services can realize more effects than individual service. Especially the peak cutting recommendations and energy analysis reports help energy consumers to learn and understand how to save and manage energy usages that lead to effective DR potentials. Also the experimental system developed for energy data measurement and DR management as an island community EMS is intrduced.     

Extraction of Volatile Compounds from Aqueous Solution using Micro Bubble, Gaseous, Supercritical and Liquid Carbon Dioxide

When separating volatile compounds from aqueous solution using supercritical carbon dioxide (SC CO₂), methods to bring SC CO₂ into contact with volatile compounds in the solution are very important. An extraction using micro bubble, gaseous, supercritical, and liquid CO₂ generated by a filter nozzle was carried out. Under optimal conditions (20 MPa, 35°C), > 95% of volatile compounds consisting of 6 to 12 carbon atoms could be removed by extraction for 40 min at CO₂ flow rate, 4.0 g/min. Extraction at 35°C could achieve either a selective or nonselective separation by adjusting the extraction pressure, since the effect of pressure on extraction ratio was most significant at 35°C.     

Sorption of Volatile Compounds in Aqueous Solution by Ethylene-Vinyl Alcohol Copolymer Films

Sorption of volatile compounds by ethylene-vinyl alcohol copolymer (EVOH) films from an aqueous solution was investigated to evaluate the merit of their use for food packaging. With regard to EVOH, equilibrium swelling values gave rise to a bimodal solubility parameter distribution with maxima at δ values of 8.5 assigned to ethylene units and 14.5 to vinyl alcohol units. Comparing distribution ratios of EVOH with those of middle-density polyethylene (MDPE), the ratios were 1:100 for terpene hydrocarbons, 1:10 for esters, 1:2 for alcohols, and almost 1:1 for aldehydes. By biaxial orientation of EVOH film, the sorption could be depressed below 60%. These results suggested EVOH films are more appropriate than MDPE for food container lining.     

Research on Maximizing Power Transfer Efficiency of Wireless In‐Wheel Motor by Primary and Load‐Side Voltage Control

The authors have developed a wireless power transfer (WPT) system for an in‐wheel motor (IWM). It is called a wireless in‐wheel motor (W‐IWM). This paper presents a method that enhances the WPT efficiency in this system. Some methods that maximize the power transfer efficiency by power converter control have been proposed in the past WPT research. In this research, a dc‐dc converter is inserted on the receiver side to vary the load state. However, the space on the receiver side is very small for the W‐IWM; therefore, it is preferable to make the secondary circuit small. Therefore, a full bridge converter is used instead of a dc‐dc converter in the W‐IWM. In this paper, the authors propose a theoretical formula for the transfer efficiency of the IW‐IWM. From an analysis of this formula, there is a combination of a primary voltage and load voltage that maximize the efficiency. The feasibility is validated by an experiment using a motor bench set.