Three‐Phase Current Control by Dynamic Reconstruction of Undetected Currents for AC Motor Drives

This paper proposes new three‐phase current control methods for AC motor drives, which detects only a phase current from among three‐phase currents. The first proposed method first detects a phase current, and then estimates the two‐phase current in the stationary reference frame using the detected single phase current. The second proposed method first detects a phase current, then synthesizes the two‐phase quasi‐current in the dq rotating reference frame, and finally produces two‐phase current estimates by extracting the positive‐phase component from the quasi‐current. The third proposed method produces two‐phase current estimates by filtering out the negative‐phase component from the quasi‐current. This paper presents the principles and detailed characteristic analyses of the proposed methods and validates them on the basis of extensive experiments.     

Immobilized Glucose Isomerase Use in Mirin Production

The conversion of glucose in mirin (an alcoholic seasoning) to fructose using immobilized glucose isomerase (IGI) was studied in order to produce sweetened mirin without chill haze. The initial conversion velocity (C_m/t_m) with IGI was affected by temperature, pH, and ethanol concentration. This reaction was first order, for which the temperature coefficient (Q₁₀) over the range 20–55°C was 2.0. The value of C_m/t_m was a maximum at pH 8.0, and decreased with an increase in ethanol. Conversions carried out in a continuous column reaction system had C_m/t_m values 36 times higher than that in a batch system. Mirin treated with IGI did not form chill haze.