This paper investigates an improved control strategy for a doubly-fed induction generator (DFIG) based wind-power generation system with series grid-side converter (SGSC) under network unbalance and harmonic grid voltage distortion conditions. The integrated mathematical modeling of the DFIG system with SGSC is established by taking both the negative-sequence and harmonic components of the grid...

Hysteresis current control method is vastly used in PWM inverters because of simplicity in performance, fast control response and good ability in limiting peak current. However, switching frequency in hysteresis current control method with fixed bandwidth has large variation during a cycle and therefore causes non-optimal current ripple generation in output current. One of basic problems in imp...

It has previously been found that when a single low-numbered harmonic of a complex tone is progressively mistuned, for mistunings up to about 3%, the pitch of the complex changes in the direction of the mistuning but for larger mistunings (by about 8%) the pitch returns to its original value. This result is compatible with the operation of a mechanism such as a graded harmonic sieve, which can ...

In phase measurement systems that use phase-shifting techniques, phase errors that are due to nonsinusoidal waveforms can be minimized by applying synchronous phase-shifting algorithms with more than four samples. However, when the phase-shift calibration is inaccurate, these algorithms cannot eliminate the effects of nonsinusoidal characteristics. It is shown that, when a number of samples bey...

Two experiments investigated the role of the regularity of the frequency spacing of harmonics, as a separate factor from harmonicity, on the perception of the virtual pitch of a harmonic series. The first experiment compared the shifts produced by mistuning the 3rd, 4th, and 5th harmonics in the pitch of two harmonic series: the odd-H and the all-H tones. The odd-H tone contained odd harmonics ...

During the last decades studies addressing the effects of exposure to Extremely Low Frequency Electromagnetic Fields (ELF-EMF) have pointed out a possible link between those fields emitted by power lines and childhood leukaemia. They have also stressed the importance of also including in the assessment the contribution of frequency components, namely harmonics, other than the fundamental one. B...

An acoustic model of pathological voice production is presented. It describes the non-linear effects occurring in the acoustic waveform of disordered voices. The noise components such as fundamental frequency and amplitude irregularities and variations, sub-harmonic components, turbulent noise and voice breaks are formally expressed as a result of random time function influences on the excitati...