The dc sources that feed the multilevel inverter are varying in time, and the switching angles should adapt to the dc source variations. Any variations in the input will result in harmonics at the output. To mitigate the harmonics in the inverter output, GA is used. A genetic algorithm optimization technique is applied to determine the switching angles for a cascaded multilevel inverter. Then, ...

Current and voltage waveforms of a distribution or a transmission system are not pure sinusoids. There are distortions in these waveforms that consist of a combination of the fundamental frequency, harmonics and high frequency transients. This paper presents an enhanced measurement scheme for identification and tracking of harmonics in power system. The proposed technique is not limited to stat...

The Power Quality Centre at the University of Wollongong has been in operation since 1996 and has made progress in many areas of power quality, with power system harmonics being a major focus. The paper will discuss some important issues in harmonics still needing to be resolved, including (i) the economic case for harmonic control, (ii) the setting of appropriate voltage limits, (iii) measurem...

In this paper we propose a multiple frequency harmonics model for analysis and synthesis of audio signals. The novelty of this model is that a composite sound can be represented by a few number (two or three) of frequency harmonics, each with time-varying fundamental frequency. We present the model and some key issues in tuning it. Results demonstrate that the model is valid and promising. It i...

this paper presents a new control methodology for active power filters that provide an adaptive online harmonic estimation with partial and selective harmonic reduction schemes, which has been implemented within an integrated controller. the proposed approach is to provide partial and selective reduction of those individual harmonics which exceed the recommended levels as set by regulatory bodi...

Since there are backlash friction and time-varying stiffness, the characteristics of gear pair has strong nonlinearity. When a gear has faults such as pitting, spalling and tooth breakage, there are often some nonlinear characteristics as super-harmonics or sub-harmonics along with vibration signal. These characteristics will cause some difficulty for fault diagnostics, so it is necessary to st...

The paper deals with the LTI/LTV power system models and their experimental verification. The frequency dependent system impedance is used for power system harmonics studies. As a voltage/current power system transfer function it explains well harmonics related phenomena observable in real systems. With very accurate impedance measurements power system nonlinearity can be observed. The nonlinea...

The peak frequency of the terahertz radiation generated from femtosecond laser-induced air plasmas is blue shifted with increased second harmonics intensity when a high voltage added upon plasmas. This shift result DC-biased field plus AC-biased harmonics, indicating that this tunable by varying two components. significant to various applications such as remote sensing and material characteriza...