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This is a crucial parameter for pump selection and is a popularly used parameter for ascertaining industrial requirements. By eliminating the inlet head, we remove the effect of the supplied pressure to the pump and are left with only the pump’s energy (head) contribution to the fluid flow. Schematic representation of pressure heads in a pump.
Direct torque control (DTC) is one method used in variable-frequency drives to control the torque (and thus finally the speed) of three-phase AC electric motors.This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor.
The motor may not reach this theoretical speed because there are non-linear mechanical losses. On the other hand, if the motor is driven as a generator, the no-load voltage between terminals is perfectly proportional to the RPM and true to the of the motor/generator.
[citation needed] Calculation: 0.9 × 0.9 = 0.81 Individual traction motor ratings usually range up 1,600 kW (2,100 hp). Another important factor when traction motors are designed or specified is operational speed. The motor armature has a maximum safe rotating speed at or below which the windings will stay safely in place.
If all switches are open the motor is completely disconnected from the three-phase network. To start the motor, first the switches 1 and 2 are closed. This supplies the motor a lower voltage from the autotransformer. The lower voltage limits the input current to the initially stationary motor, which accelerates. The torque of the motor is also ...
In vector control, an AC induction or synchronous motor is controlled under all operating conditions like a separately excited DC motor. [21] That is, the AC motor behaves like a DC motor in which the field flux linkage and armature flux linkage created by the respective field and armature (or torque component) currents are orthogonally aligned such that, when torque is controlled, the field ...
Usually utilization category is mentioned in most of the switch gear, with the above contactor stating to be used under AC1 - resistive load & AC3 for motor usage. In electrical engineering utilization categories are defined by IEC standards [1] and indicate the type of electrical load and duty cycle of the loads to ease selection of contactors ...
A coordination study allows selection and setting of protective relays and fuses to rapidly clear a short-circuit fault while minimizing effects on the rest of the power system. Transient or dynamic stability studies show the effect of events such as sudden load changes, short-circuits, or accidental disconnection of load on the synchronization ...