ELECTRICAL DRIVES DRIVE TECHNOLOGY

Load behaviour of drives

E2.5.4.4

Operating behaviour of speed-variable asynchronous motors under load (E2.5.4.4)

The learner will get to know the behaviour of working machines on a drive with asynchronous motor.

In later experiments, the different behaviours of working machines are presented.

Characteristics diagrams and time diagrams are recorded and analysed for evaluation purposes.

Objectives

Energy requirement for starting under load

Energy requirement for change of direction of rotation

Behaviour of working machines

Torque is constant as with lifts; cranes (TL = const.)

Torque rises lineally with speed; extruder, flexing work (TL ~ n)

Torque rises quadratically with speed; turbo machines, fans, pumps (TL ~ n²)

Torque decreases inversely proportional to speed; lathes and milling machines, winding machines (TL = 1/n)

Flywheel mass

The pictured experiment stand is not included in this equipment. It can be added on request for an extra charge.

The pictured experiment stand is not included in this equipment. It can be added on request for an extra charge.

Electrical Drives Drive Technology

Load behaviour of drives

Direct current machines are no longer so popular among controlled and regulated drives. The high purchase price and maintenance costs arising due to the brushes mean these have largely been replaced by BLDC machines. Despite the aforementioned disadvantages, this drive is still used in drive technology because of its highly dynamic control behaviour.

The learner will get to know the behaviour of working machines on a drive with direct current motor. In the first few experiments, the efficiency of a speedvariable drive is investigated. In later experiments, the different behaviours of working machines are presented.