Control Model for Large‐Sized Gantry Type Linear Motor Slider

At present, many industrial carrier devices utilize linear motor sliders. However, a heavier load requires a linear motor (which is an example of a direct drive device) to get higher power, compared with a rotary motor with a ball screw slider (which is an example of an indirect drive device). In order to obtain higher power at a lower cost, a linear slider with multiple motors can be utilized, for example, a gantry type linear motor slider. Moving the gantry type slider requires two linear motors that are set up in parallel to enable synchronization control. Some conventional synchronization control methods have been proposed for the parallel twin linear slider; however, a large‐scaled gantry type linear motor slider has two unique problems: mechanical distortion caused by the limitations of installation environment and coupling caused by joints with low stiffness. This paper proposes a control model to solve these problems, and an identification method of each parameter. Furthermore, the effectiveness of the control model is verified by comparison with simulation results and experimental results.     

Parallel Multipopulation Differential Evolutionary Particle Swarm Optimization for Voltage and Reactive Power Control

This paper presents parallel multipopulation differential evolutionary particle swarm optimization (DEEPSO) for voltage and reactive power control (VQC). The problem can be formulated as a mixed integer nonlinear optimization problem and various evolutionary computation techniques have been applied to the problem including PSO, differential evolution (DE), and DEEPSO. Since VQC is one of the online controls, speed‐up of computation is required. Moreover, there is still room for improvement in solution quality. This paper applies parallel multipopulation DEEPSO in order to speed up the calculation and improve solution quality. The proposed method is applied to IEEE 30, 57, and 118 bus systems. The results indicate that the proposed method can realize fast computation and minimize more active power losses than the conventional evolutionary computation techniques.     

Development of –1 MV DC Filter and High‐Voltage DC Measurement Systems for ITER NBI

This paper presents the development results of a ?1 MV dc filter and dc measurement systems for an ITER (International Thermonuclear Experimental Reactor) neutral beam injector (NBI) system. High accuracy of 0.5% and fast responsivity of 3.3 μs, ?3 dB are required for the dc measurement systems: both dc voltage dividers and DCCTs. Circuit design and thermal flow design were carried out to clarify and minimize their effects on the accuracy and responsivity. The validity of the established design was demonstrated by the actual‐product tests; temperature rise of each components fell below the allowable value; inner components of dc filter withstood dc ?1.2 MV; each voltage divider accurately measured the voltage during the dc ?1.2 MV withstand voltage test; the voltage dividers and the DCCTs were adequate to the requirements of responsivity (3.3 μs, ?3 dB).     

Quality Improvement and Evaluation of Hypoallergenic Rice Grains

The color of hypoallergenic rice grains, produced by an enzymatic process was improved by treatment with diluted hydrochloric acid and washing with water. The acid-treated grains were steamed at the surface layer to prevent breakage. Textural evaluation showed the cooked hypoallergenic rice grains had a favorable stickiness/hardness ratio.     

High Precision On‐Line Offset Correction for Motor Angle Sensors

In this paper, an angle detecting system is proposed that calculates the offset correction values for the sine and cosine signals of angle sensors. The offset correction values are calculated not from the offset errors of the sine and cosine signals but from the 1f angle error (the fundamental frequency component of the sine and cosine signals) of the angle signals. Therefore, the system can correct the 1f angle error even when the sine and cosine signals contain the double‐frequency components of the sine and cosine signals, as well as the dc offset errors. Moreover, it is possible to use low‐cost microcomputers with low computing speed, because the offset correction values are dc quantities.     

Ohmic heating of Japanese white radish Rhaphanus sativus L.

Ohmic heating was applied to Japanese white radish, Rhaphanus sativus L. at 50 Hz-10 kHz and 40 V cm⁻¹ to examine the effects of frequency on the heat generation. Of the frequencies examined, 50 Hz gave the sharpest initial rise of temperature and the shortest time to raise the temperature at the mid-part of radish to 80°C. The heating rates above 60°C were found to be almost the same and linear for all the frequencies. The pressurization (400 MPa, 25°C, for 10 min) of radish eliminated the sharp initial increase of temperature observed at 50 Hz, and gave an almost linear rise of temperature similar to those above 60°C. When radish was treated with a square wave (10 ms with 10 ms interval) of 45 V cm⁻¹ for 30 s, its impedance decreased and never recovered even after storage at room temperature for 20 h. When radish was treated at 50 Hz and 40 V cm⁻¹ until its mid-part reached 30°C, or heated to 80°C in hot water and then cooled to 30°C, ¹H-NMR imaging analysis showed more free movement of liquid components than in untreated radish. These results suggest that the initial rapid heating up at low frequency is caused by the electroporation of radish tissue membrane, resulting in the reduction of its impedance.     

Demonstration of Loss‐reduction Effect of the Amorphous Cores for Larger‐Capacity Transformers by Trial Manufacture

For the demonstration of feasibility and loss‐reduction effect of the larger‐capacity amorphous core transformers (AMT), this paper proposed the support structure and design method of the iron‐loss reduced amorphous wound cores with a weight of 7 tons. We designed and manufactured 10 MVA single‐phase test model with the cores inserted in a support cage having structures of the stress‐buffered core support, the proof electromagnetic force from the windings, and the stray loss‐reducing shields. The 50%‐loaded total loss of the test model estimated from the calculated and measured results has been reduced by 35% compared with a conventional silicon‐steel core transformer (SST) with the same power capacity.