Starting of large flywheel masses with slip-ring motor

The heavy start is left to the slip-ring rotors. The starting current can be reduced to the nominal current by switching through the resistors in the rotor circuit.

In this experiment, the manual rotor starter is available for the heavy start.

Objectives

• Mains feedback with heavy start
• Mechanical load of the driven working machine
• Optimisation of a start control
• Energy requirement for direct start of an asynchronous motor
• Energy requirement for soft start of an asynchronous motor

The following parameters are determined:

Load simulation:

• Starting current
• Rotor current
• Optimising starting times for automatic control
• Starting torque
• Tilting torque
• Nominal torque
• Maximum acceleration

Highlights:

• The measurements are carried out with the CASSY Machine Test.
• All measurement channels are potential-free and can therefore be used freely.
• All measurements can be carried out with or without a computer.
• In order to protect against overheating, the stator windings of the slip-ring motor are equipped with thermal detectors.
• The slip-ring motor has an educationally designed terminal board with the winding configuration printed on it.

All functions of the Machine Test CASSY 0.3 can be operated quickly and directly via the display, the rotary wheel and the buttons on the unit. All settings and measurement results can be saved on the unit and quickly called up again later or simply downloaded.

In addition, the Machine Test CASSY 0.3 is fully controllable in real time via RJ45 Ethernet, W-LAN and USB-C interfaces.

These interfaces can be used by the following software:

• CASSY Lab 2 for drives and energy systems,
• MATLAB® and LabVIEW ™
• Lab Docs Editor Advanced

The following integrated servers are available in the Machine Test CASSY 0.3 for the local media connection of at least four end devices simultaneously.

For more details, see product data 7731900 or 7731901 Machine Test CASSY 0.3

The equipment is equally suitable for pupil and student experiments in the laboratory with low voltage (DC, AC and three-phase current) and - with a mobile trainer - for teacher demonstrations in the classroom or lecture hall. The experiments are carried out according to the manual.

The target group is made up of commercial apprentices and students of electrical machine construction. The course offers experiments at an intermediate level and also allows for the necessary insight into machine behaviour for scientific interpretation at undergraduate level. The media connection makes the experiments suitable for demonstration in the classroom or a lecture hall.

 In the following configurations there are further extended experiments performed with a slip-ring rotor machine:

• E2.2.4.4 Slip-ring rotor 0.3
• E2.5.3.1 Static converter drives with asynchronous machines

Topics

• Heavy start with medium flywheel mass
• Heavy start with large flywheel mass
•  Measuring switching times between the increments
• Measuring the required energy for starting change of direction of rotation