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The conducted EMI noise flowing from power converters to an AC utility line is regulated by international commissions such as the International Electrotechnical Commission (IEC). Adherence to the IEC regulations requires that EMI filters should be used in power electronics equipment. This paper proposes a method for analyzing conducted EMI noise in multiple power converters connected to the same power line. In this method, the phase difference between subharmonic modulated carrier signals at each power converter is taken into account. The phase difference among the power converters determines the EMI noise level in a multiple converter system, as is evident from the analysis of the waveform of the common mode current. In addition, EMI noise suppression using carrier phase control is proposed. In order to reduce the size of the EMI filter effectively, the phase difference θ should be set to 360/ nN°, where n is a high-order harmonic component near 150 kHz and N is the number of power converters. Therefore, the conducted EMI noise can be reduced effectively with the help of the proposed phase control. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(3): 56-66, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21305 [ABSTRACT FROM AUTHOR]

High-frequency leakage current that may cause serious conducted EMI problems flows through an inverter system. The paths of the leakage current are stray capacitances that are formed inside of motors, cables, and IGBT modules. This paper proposes a new IGBT module that realizes low conducted emission noise by flipping the IGBT chip of the lower-voltage side to decrease its stray capacitance. The leakage current flowing through the low-noise IGBT module becomes small, since the stray capacitance is a main path of the current. Through an experiment, it is clarified that the conducted emission level is reduced by 13 dB at a maximum when the low-noise IGBT module is applied to a resonant-type inverter. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(4): 45–52, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20971 [ABSTRACT FROM AUTHOR]

This paper presents a novel lightweight linear actuator using permanent magnets and having its coils on the stator concentratedly. The rated force is 6 N, the stroke is 30 mm, and the weight is below 300 g owing to its unique structure. The machine is to be applied to, e.g., a pick-and-place actuator of tiny electronic parts, and the performance for the application is confirmed through experiments with a prototype. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(4): 59–67, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20158 [ABSTRACT FROM AUTHOR]