Electrotechnical Systems

267Electric Machine and Electric Drive Simulation

rated speed. In the rst mode, the switch is in the upper position, and SR (Discrete

PI Controller) output comes to the CR input through the module detector and the

limiter. As a feedback, the measured reactor current I

d

is used. The SR operate with

signals in SI, so the rotor rotation speed signal measured in pu is recalculated in

rad/s, and I

f _ref

reference signal is divided by the base current value. As it was said

earlier, I

f _ref

increases with increasing of I

d

or is controlled in order to provide the

reference value of Ψ

se

.

In the current control mode, Switch1 is in the lower position, SR is disconnected,

and at CR input, either the constant reference start current (it is set 150 A) or ...