Abstract: Method for detecting and/or monitoring the temperatures of at least two electronic power switches, in particular semi-conductor power switches that are coupled with or arranged on a common cooling body, whereby a temperature detection and/or monitoring is carried out by means of a temperature model each allocated to a switch, in which switch and operating parameters as well as temperature measurement values are processed for calculating the temperature and/or a temperature difference in the relevant switch, whereby a temperature measurement value from a temperature sensor is used as an input parameter for the temperature model, the same being centrally positioned between at least two switches and standing in a heat conducting connection with the cooling body.

Abstract: A field-oriented control method for an electric drive comprising a plurality of electric motors, for implementing a tension mechanism, especially for load cable and/or gearing means, using measurements of a polyphase motor actual current. The measured values are transformed into a direct current component and a quadrature current component, based upon a magnetic rotor field or flux angle, in a rotor flux-based d,q coordinate system. The quadrature and direct current components from the actual current are subjected to a comparison with predetermined quadrature and direct current components of a current command value.

Abstract: A field-oriented control method for an electric drive comprising a plurality of electric motors, for implementing a tension mechanism, especially for load cable and/or gearing means, using measurements of a polyphase motor actual current. The measured values are transformed into a direct current component and a quadrature current component, based upon a magnetic rotor field or flux angle, in a rotor flux-based d,q coordinate system. The quadrature and direct current components from the actual current are subjected to a comparison with predetermined quadrature and direct current components of a current command value.

Abstract: A method and a control device for braking a variable speed vector controlled induction machine are driven by a pulse width modulation (PWM) inverter, in which the q-current component and the d-current component of the stator current are controlled independently from one another in accordance with a first reference signal (iq*) and a second reference signal (id*), respectively. For braking, high frequency components are superimposed on the second reference signal (id*), and the root-mean-square (rms) value (id rms) and the average value (id av) of the resultant second reference signal are controlled independently from one another such that the field requirements are met by the average value and high machine losses are produced by the rms value.