Study On Dead-time Effect In Inverter And Typical Methods Of Compensation

At present, the SPWM AC-DC-AC inverter has been widely applied. However, with the development of the modern power electronic device , the frequency of the switch is being heightened constantly, dead-time effect is more and more serious to affect the whole system. Dead-time effect issue arouses the attention of many scholars, to compensate the influences of dead-time becomes an important subject to improve the waveforms of inverter.Firstly, this paper studies the dead-time and its effect on the inverter output voltage and the whole system. The effect of dead-time results in reduction of the fundamental component of inverter voltage , phase shifting and addition of unwanted low order harmonics. Specially when output voltage is very low, the distorted voltage may give rise to serious problems and increased torque ripples ,which results in unstable operation of the system. So it is necessary to compensate dead-time effect for the high performance operation of frequency conversion system.Secondly, current feedback for dead-time compensation method and on-line dead-time compensation method using disturbance observer are studied, on the base of presentation various compensation methods. Matlab simulation is used to prove the availability and the feasibility of the proposed two schemes.Lastly, the advantage and disadvantage of the two compensation methods is shown in the paper by comparing the simulation results of the proposed two schemes. The studies of this paper have the value for improving the performance of the AC machine driver and the further study of the dead-time effect.