In order to obtain high performance, in the overload torque and in the transient regime, the inverters of this type carry out a flow control with the following functions: – estimation of the electric motor load made by measuring the current in the continuous stage of the inverter , – estimation of stator resistance.
This is the purpose of the engine gauge, known for the adjustment of the thermal protection and its thermal state. These two estimates allow calculating the voltage to be employed in the motor, at a given speed, to achieve the improved flow, – frequency gain. Prevents engine disconnection by preserving its constant torque. This is achieved by lowering the voltage and frequency, – over transient power.
An early rise in voltage is supplied to the motor SealMaster PN-32T during rapid decelerations, in order to keep the flow in a transient regime. This function is sometimes called “kinematic boost”, – slip compensation. In order to preserve the substantially constant rotational speed, the motor is fed at a slightly higher fret rate than on empty. This frequency rise is a function of the estimated load described above and the rated slip frequency of the motor.