We present in this short note a simple perturbation scheme to derive a reduced description of the dynamics of reaction-diffusion systems deep in a temporally ordered state. This work was motivated by Ortoleva and Ross' phase-wave theory of heterogeneous reaction-diffusion system in which the degree of heterogeneity is taken as a small parameter.!) In contrast to their work, however, we consider...

1 November 2001 Alternating Current Theory J R Lucas An alternating waveform is a periodic waveform which alternate between positive and negative values. Unlike direct waveforms, they cannot be characterised by one magnitude as their amplitude is continuously varying from instant to instant. Thus various forms of magnitudes are defined for such waveforms. The advantage of the alternating wavefo...

Recently wide spread of power electronic equipment has caused an increase of the harmonic disturbances in the power systems. The nonlinear loads draw harmonic and reactive power components of current from ac mains. Current harmonics generated by nonlinear loads such as adjustable speed drives, static power supplies and UPS. Thus a perfect compensator is required to avoid the consequences due to...

Shunt Active Power Filters (SAPFs) represent the most important and widely used filter in industrial purposes due to the fact that, they not only eliminate the harmonic current with a neglected amount of active fundamental current supplied to compensate system losses, but also they are suitable for a wide range of power ratings. One of the key issues for a proper implementation of an active fil...

active filters have proven to be more effective than passive techniques to improve power quality and to solve harmonic and power factor problems due to nonlinear loads. this paper proposes a control scheme based on the instantaneous active and reactive power. the inverter of this active filter is a three-phase, two-level converter. space vector technique is used as modulators and pattern genera...