Danfoss Drives A/s

Bauer Gear Motor Gmbh

Karl-Peter Simon

Walter Trümpler

A drive with integrated dynamic load control includes a three-phase asynchronous motor having three phase legs connected in a star circuit, each phase leg having a winding having a coil end connected to a common star point. A load control circuit has a regulating module, an ammeter, a voltmeter and first and second switches. The ammeter and voltmeter detect a phase current and a phase voltage in one phase leg. The regulating module calculates an active power of the phase leg and a total active power of the motor responsive to the phase current and phase voltage. The switches are arranged in two of the phase legs between the respective coil end and the star point and the regulating module interrupts the two phase legs by using the switches when the active power, the total active power or a torque calculated from the total active power exceeds an adjustable limit value.

Drive with integrated dynamic load control

The invention concerns a method for detecting a fault in a rotating field machine, in which current components are analysed in a flux-based, particularly rotor-flux-based, coordinate system a flux-forming current component being subjected to a frequency analysis in the flux-based, particularly rotor-flux-based, coordinate system. It is endeavored to provide a simple method for an early detection of faults. For this purpose, a current operating point is detected for at least one predetermined supply frequency (f), said operating point being compared to a former operating point.

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Grünstadt, Germany

Karl-Peter Simon