Mitsubishi Electric Corporation

Mitsubishi Electric Research Laboratories, Inc.

Retsu Sugawara

Philip Orlik

Dehong Liu

Kazutoshi Awane

Jun Takahashi

Yuji Matsuda

Yudai Yoneoka

A controller is provided for generating carrier signals controlling a pulse width modulation (PWM) inverter driving an electric actuator. The controller includes an interface configured to connect to a victim circuit via sensors, wherein the victim circuit includes the power system or the electric actuator or a combination of the power system and the electric actuator, wherein the sensors are configured to measure an electromagnetic-interference (EMI) spectrum, a memory configured to store modulation frequency ranges, the measured electromagnetic-interference (EMI) spectral data of different frequency carriers, a desired EMI spectrum and a learning-based carrier design program, and a processor, in connection with the memory, configured to perform generating a frequency modulation (FM) carrier signal by solving an optimization problem, wherein the optimization problem is generated regarding a sweep time for a predetermined frequency by the learning-based carrier design program, and a PWM generator configured to generate PWM signals based on the FM carrier signal.

Electromagnetic interference (EMI) mitigation in pulse width modulation (PWM) inverters using learning-based frequency modulated carriers

A noise elimination device includes a noise elimination unit to generate a noise-eliminated spectrum by performing noise elimination on the basis of symmetry of noise superimposed on a reception signal spectrum.

Noise elimination device, antenna device, and noise elimination method

A common mode choke coil includes: a magnetic core; and a pair of coils wound on a winding portion of the magnetic core, wherein the pair of coils include a first pole coil and a second pole coil which are each wound on the winding portion in a spiral shape by N turns, and wherein the first pole coil and the second pole coil are arranged on the winding portion so that one or more turns of the N turns are adjacent to each other, and each include a parallel running portion and a non-parallel running portion, the first pole coil and the second pole coil overlapping each other in the parallel running portion, and separating from each other in the non-parallel running portion in at least one turn of the adjacent first pole coil and second pole coil as viewed from the length direction of the winding portion.

Common mode choke coil

A controller is provided for generating carrier signals for a PWM generator controlling an inverter driving an electric actuator to reduce the EMI level of the inverter. The controller includes an interface configured to connect to the inverter, a memory configured to store a measured electromagnetic-interference (EMI) spectrum, a desired EMI spectrum and an EMI suppression rate program, and a processor. The processor is, in connection with the memory, configured to computing EMI suppression rates for a frequency range, wherein the EMI suppression determined adaptively by the measured EMI spectrum and the desired EMI spectrum, computing sweep duration of discrete frequency, wherein the sweep duration is determined by the EMI suppression rate of the discrete frequency, and a modulator configured to modulate the carrier signals based on the sweep durations of carrier frequencies and to transmit the modulated carrier signals to the PWM generator to generate PWM signals for the inverter.

EMI reduction in PWM inverters using adaptive frequency modulated carriers

A capacitor has a parasitic inductance component and is electrically connected between a positive line and a negative line. A converter includes a reactor provided in the positive line and performs voltage conversion of a DC voltage smoothed by a capacitor. An inverter performs DC-AC conversion between the converter and an AC motor by switching control. A path of the positive line which connects a DC power supply and the capacitor has an inductance smaller than an inductance of a path of the negative line which connects the DC power supply and the capacitor. A difference between the inductance of the path and the inductance of the path is less than twice the parasitic inductance component.

Growing community of inventors

Tokyo, Japan

Retsu Sugawara