In order to achieve high performance in the overload torque and in the transient regime, the inverters of this type perform a flow control with the following functions, the estimation of the electric motor https://www.mrosupply.com/popular_products/05-hp-56-motors/ load realized from the measurement of the current in the continuous stage of the inverter and the estimation of the stator resistance. This is a function of the motor gauge, known for the regulation of the thermal protection and its thermal state. These two estimates guarantee the calculation of the voltage to be applied to the motor, at a given speed, to obtain the optimized flow, obtaining a frequency gain.
The flow control prevents motor disconnection by keeping its torque constant. This is obtained by reducing the voltage and frequency by transient overfeeding. A precipitated rise in voltage is supplied to the motor during rapid decelerations in order to keep the flow in a transient regime. This function is sometimes called “kinematic boost”, – slip compensation. To maintain the rotational speed substantially constant, the motor is fed at a slightly higher fret rate than in the vacuum. This increase in frequency is a function of the estimate of the rated load and the nominal slip frequency of the motor.