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The dual-stator-winding induction generator (DWIG) designed to achieve wide-speed-range operation with reduced capacity of the static power controller is presented. The DWIG consists of a standard squirrel-cage rotor and a stator with two separate windings wound for the same number of poles. This generator has a diode bridge rectifier load connected across to the power winding and a static excitation controller (SEC) to the control winding. Investigations into the reactive power released by the fixed excitation capacitor bank versus rotor speed under various loads represent that the minimal capacity of SEC can be achieved by an appropriate selection of excitation capacitor bank. With the help of instantaneous power theory, the control mechanism for the DWIG system working with a variable rotor speed is analyzed. Moreover, the system control strategy which is fit for the wide-speed-range operation using the stator flux orientation is consequently proposed. An 18-kW DWIG system with a 270-V high voltage dc output is developed. The simulation and experimental results illustrate a desirable performance, and the compact implementation of SEC is obtained. Index Terms--Capacity optimization, dual-stator-winding induction generator (DWIG), stator flux orientation control, voltage-source inverter.

Retinoic acid receptors (RAR) belong to the same nuclear receptor superfamily as thyroid hormone receptors (TR) that were previously shown to be modulated by dietary soy protein isolate (SPI). This study has examined the effect of dietary SPI and isoflavones (ISF) on hepatic RAR gene expression and DNA binding activity. In Expt. 1, Sprague-Dawley rats were fed diets containing 20% casein or 20% alcohol-washed SPI in the absence or presence of increasing amounts of ISF (5-1250 mg/kg diet) for 70, 190, or 310 d. In Expt. 2, weanling Sprague-Dawley rats were fed diets containing 20% casein with or without supplemental ISF (50 mg/kg diet) or increasing amounts of alcohol-washed SPI (5, 10, and 20%) for 90 d. Intake of soy proteins significantly elevated hepatic RAR[beta]2 protein content dose-dependently compared with a casein diet, whereas supplemental ISF had no consistent effect. Neither RAR[beta] protein in the other tissues measured nor the other RAR (RAR[alpha] and RAR[gamma]) in the liver were affected by dietary SPI, indicating a tissue and isoform-specific effect of SPI. RAR[beta]2 mRNA abundances were not different between dietary groups except that its expression was markedly suppressed in male rats fed SPI for 310 d. DNA binding activity of nuclear RAR[beta] was significantly attenuated and the isoelectric points of RAR[beta]2 were shifted by dietary SPI. Overall, these results show for the first time, to our knowledge, that dietary soy proteins affect hepatic RAR[beta]2 protein content and RAR[beta] DNA binding activity, which may contribute to the suppression of retinoid-induced hypertriglyceridemia by SPI as reported.

Our previous studies showed that intake of 20% alcohol-washed soy protein isolate (SPI) significantly increased hepatic thyroid hormone receptor (TR) [beta]1 protein content in rats. However, whether SPI influences the binding ability of TR to its target genes is unknown. The purpose of this study was to examine the effect of increasing amounts of dietary SPI on hepatic TR[beta]1 content and the binding of TR to thyroid hormone response element (I-RE) in rats. Sprague-Dawley rats (28 d old) were fed diets containing casein (20%) with or without isofiavone supplementation (50 mg/kg diet) or alcohol-washed SPI (5, 10, or 20%) for 90 d. The hepatic TR/31 protein content was measured by Western blot, and the binding ability of TR to DNA was examined by electrophoretic mobility shift assay. Consumption of the 20% SPI diet increased pancreatic relative weight and decreased spleen relative weight. Intake of SPI markedly elevated TR/31 content in both male and female rats compared with a casein-based control diet. The increase in TR[beta]1 in females was much higher than that in males. Interestingly, the binding abilities of TR to DNA were significantly inhibited by increasing amounts of dietary SPI in female rats. In conclusion, this study shows for the first time that dietary SPI increases hepatic TR[beta]1 protein content and inhibits the binding of TR to target genes. Modulation of hepatic TR[beta]1, a key regulator of gene expression involved in lipid metabolism, by SPI may be a novel mechanism by which soy components lower blood lipid level and exert their hypocholesterolemic actions. J. Nutr. 135: 1631-1635, 2005. KEY WORDS: * rat * soy protein * isoflavones * thyroid hormone receptor * binding ability

Active disturbance rejection control using extended state observer (ESO) is less dependent on the knowledge of the system. It has proved to be an excellent scheme for speed control of electrical drives. However, for time-varying disturbance, the observation precision of conventional ESO is undesired, which limits the speed tracking accuracy. Accordingly, this article proposes an enhanced speed controller for electrical drives based on adaptive switching high-order ESO (ASHESO). First, the critical parameters affecting the steady-state performance of ASHESO are determined according to frequency analytical results. Then, optimized observer gain is obtained by modifying a part of pole locations, which weakens the influence of noise on estimated state. Finally, an adaptive switching gain mechanism is proposed according to the closed-loop tracking error and the swiftness of dynamic response is maintained. The proposed speed controller has achieved high estimation accuracy for disturbance and strong immunity to measurement noise. The feasibility and effectiveness of the strategy is verified on a laboratory permanent magnet synchronous motor (PMSM) drive system. [ABSTRACT FROM AUTHOR]