Ikuro Morita

I/sub DDQ/ test method based on wavelet transformation for noisy current measurement environment

An I/sub DDQ/ test method is proposed in this paper, which is applicable even if supply current measurement is impaired by noise. Wavelet transformation is used for noise elimination in the test method. In this paper, it is shown by some experiments that bridging faults will be detected by using the proposed test method. Since expert knowledge on filter design is not needed in noise elimination of the I/sub DDQ/ test method, it is expected that the test method will be used in many I/sub DDQ/ tests.

Load characteristics comparisons of interior permanent magnet synchronous motors by pole-slot combinations

In recent years, interior permanent magnet synchronous motor (IPMSM) with concentrated windings has been interested as a smaller and higher-efficient motor than that with distributed windings. In this paper we have been analyzed the load characteristics of the eighteen IPMSM models with the various pole-slot combinations and the pole-arc angles using finite element method. The analyzed characteristics of the developed torques, that is, the magnet and of the reluctance torques, and of the torque ripple are shown and we discuss on these performance differences by the pole-slot combinations.

Wind power generation data processing system with the aid of a micro computer

In this paper, development of the wind power generation data processing system with the aid of a micro computer is discussed. The system comprises two parts, i.e. a data measuring device and a data collecting/processing device. With the micro computer, control for data collection is maintanied and the data thus obtained upon the program. Thus various kinds of the fundamental data required for the wind power generation are allowed to be gained. Furthermore, to make certain the effectiveness of the said system, results of the data collected and processed are referred to with a propeller type wind power generation system as an object.

Analysis of the Frequency Characteristics of a Three-Phase Induction Motor

In this paper, we discuss the frequency characteristics of a three-phase induction motor theoretically and take up the transfer functions on. the speed variation to the small variation of supply voltage, supply frequency, and load torque. The frequency responses are affected considerably by the electrical time constant at the range of, high signal frequency, but these transfer functions may be approximated by the form of a first-order lag element as the value of mechanical time constant or the slip of a tested induction motor increases.

Study on synchronous induction hybrid motors

Today, various interior permanent magnet synchronous motors (IPMSMs) are developed. Especially, in the capacity of 3.7 kW or less, interior permanent magnet synchronous induction motors (IPMSIM) have been interested. IPMSIM with a squirrel cage rotor has line start capability and higher efficiency than conventional induction motor. In this paper, we propose a novel hybrid motor that operates simultaneously as a synchronous motor and an induction motor, and present the characteristics as a hybrid motor obtained by 3D finite element analysis.