A VOLTAGE FEEDING ALGORITHM FOR VECTORIAL CONTROL OF LINEAR ASYNCHRONOUS MACHINES TAKING INTO ACCOUNT END EFFECT

The paper deals with a voltage feeding algorithm for a linear induction drive that takes into account the end-effect and the actual distribution of the windings. It realises a decoupled control of the thrust and of the magnetising condition of the machine. In order to take into account the end effect, different space harmonics of the flux density distribution must be considered. For this reason a suitable state observer has been adopted. The considered observer is arranged as a diagonal system of linear differential equations, therefore it gives a fast evaluation of the estimated quantities. The reference currents computed according to the field oriented strategy, are used by the feeding algorithm in order to evaluate, at each sampling interval, the reference vector of the supply voltage. This vector is adequately modulated by means of the vector PWM.