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Topic

Harmonic

About: Harmonic is a research topic. Over the lifetime, 44833 publications have been published within this topic receiving 495922 citations. The topic is also known as: overtone & partial.


Papers
More filters
Journal ArticleDOI
01 Oct 1989
TL;DR: A number of issues involved in designing a current source inverter system for a large induction motor drive are discussed and two modulation techniques are used-selective harmonic elimination in the upper frequency range and trapezoidal modulation in the lower frequency range.
Abstract: The authors discuss a number of issues involved in designing a current source inverter system for a large induction motor drive. Using two modulation techniques-selected harmonic elimination in the upper frequency range and trapezoidal modulation in the lower frequency range-control of voltage, current, and torque harmonics is achieved while limiting the GTO switching frequency to 180 Hz. Each modulation range is divided into a number of subranges to exploit the available switching capacity and to avoid harmonic resonances involving the capacitor and the motor inductance. In addition to the development of basic principles, the authors include simulation waveforms and test results from a laboratory experimental system. >

132 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed automatic gain adjustment in a fully-digital-controlled shunt active filter to damp out harmonic propagation without considering the circuit parameters, which can reduce the compensating currents and losses in the active filter and avoid over-damping performance.
Abstract: This paper discusses automatic gain adjustment in a fully-digital-controlled shunt active filter. This is the first step in cooperative control of the multiple active filters based on voltage detection for harmonic damping throughout power distribution systems. In general, the active filter should be equipped with an optimal control gain corresponding to the characteristic impedance of a distribution line. However, it is difficult to know circuit parameters of a real distribution line having various shunt capacitors and loads. Therefore, a main purpose of the gain adjustment is to make the active filter damp out harmonic propagation without considering the circuit parameters. In addition, the gain adjustment can reduce the compensating currents and losses in the active filter, and moreover it can avoid over-damping performance. Experiment results obtained from a 200-V, 20-kW laboratory system verify the effectiveness of the active filter equipped with automatic gain adjustment.

132 citations

Journal ArticleDOI
TL;DR: It is shown that rotor loss reduction is lower than expected in the MMF space harmonic amplitude and frequency distribution, and some considerations about the harmonic impact are given.
Abstract: Fractional-slot permanent-magnet (PM) machines have several advantages, but they suffer from the high content of space harmonics in the air-gap magnetomotive force (MMF) distribution. The MMF space harmonic amplitude and frequency depend on the particular combination of numbers of slots and poles. Such harmonics induce losses in the rotor since they are not synchronous with the rotor speed. This paper compares several kinds of machines with the same stator lamination but with different numbers of phases; three-, five-, and seven-phase PM machines are considered. Several winding configurations are compared, changing the number of poles but maintaining the same number of slots. Although in each case there is a reduction in terms of harmonic content, it is shown that rotor loss reduction is lower than expected. Some considerations about the harmonic impact are given. Although no experimental results are given, this paper refers to previous works in which rotor losses have been investigated and measured experimentally.

132 citations

Journal ArticleDOI
TL;DR: In this article, microstrip coupled-line bandpass filters using a Koch fractal shape are proposed for the first time, and they are fabricated on a liquid crystal polymer (LCP) substrate for Ku-band.
Abstract: In this paper, microstrip coupled-line bandpass filters using a Koch fractal shape are proposed for the first time. These filters are fabricated on a liquid crystal polymer (LCP) substrate for Ku-band. Conventional microstrip coupled-line filters are very popular for RF front ends because they can be fabricated easily. However, their large second harmonic causes the shape of the passband to be asymmetric in the upper band and it worsens the skirt properties. By proper design, the second harmonic of fractal filters can be significantly suppressed through the use of fractal shapes. In this paper, using LCP, the maximum harmonic suppression was almost 42 dB. This type of filter can be used to suppress the second harmonic without any additional devices and regardless of the substrate.

132 citations

Journal ArticleDOI
TL;DR: In this article, the effect of eddy-current loss reduction by the magnet segmentation in synchronous motors with concentrated windings is investigated, and the effect depends on the types of the rotors, for instance, interior and surface permanent magnet rotors.
Abstract: In this paper, we investigate the effect of eddy-current loss reduction by the magnet segmentation in synchronous motors with concentrated windings in order to understand appropriate segmentation methods. The loss-reduction effects in each harmonic eddy current in the magnets are analyzed by both the theoretical solution and the three-dimensional finite-element analysis with Fourier transformation. The basic experiments using magnet specimens are carried out in order to support the calculated results. It is clarified that the loss-reduction effect varies with the harmonic orders and that the effect depends on the types of the rotors, for instance, interior and surface permanent-magnet rotors.

132 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,223
20222,724
20211,878
20202,330
20192,612
20182,495