Starting from the intrinsically vectorial non-paraxial propagation equations,and employing the Fourier transforming and the angular spectrum formalization,the influence of the vectorial effects on the non-paraixal propagation of ultrashort pulsed beam in free space is analyzed.

Furthermore,we have investigated the roles of n on-paraxial and vectorial effects in self-focusing of very narrow beams by a m odulation theory.

Analysis of dead-time effect in cascaded multi-level medium-voltage inverters;

Analysis and countermeasures of dead-time effect in shunt active power filter

Setting of dead-time prevents direct connection between inverter components,however,it also comes into bring dead-time effect,especially in DTC,the effect is obvious.

This causes well known dead time effect which distorts the output voltage and current.

Research for compensation of dead-time effects based on MSPWM inverters;

Torque ripples of permanent magnet synchronous motor caused by space vector pulse width modulation and dead-time effects are analyzed,calculation formulas of current ripple quantity and error flux linkage vector caused by SVPWM are deduced,and error voltage vector and dead-time effects caused by dead-time are analyzed.

Error voltage vectors caused by dead-time effects of PWM inverter were given,the vector synthesis method was adapted to educe amplitude and phase formulas of synthesized voltage vector produced by 3-phase stator windings under dead-time effects,the characteristic of synthesized voltage vector was analyzed with simulations.

To compensate the deadtime effect, some methods have been proposed, but they are often too complicated or need additional hardware.