Grundfos A/s

Grundfos Management A/s

Grunfos A/s

Jan Caroe Aarestrup

Niels D Jensen

Keld Folsach Rasmussen

Jens Engen Soerensen

Klaus Sloth Jensen

A method serves for starting a polyphase electric motor which is operated in a star connection. The method conductively bridges at least one winding part of a phase of the motor and electrically disconnects the bridged winding part, in order in this manner, to supply a higher voltage to the remaining, electrically effective windings, and thus to increase the flow of current and thus the torque.

Method for controlling a multiphase electric motor operating in star-connected mode

The method for activating an asynchronous motor comprising at least two windings is provided, in order, for the purpose of a change in the rotational speed, to connect a first winding and at least one second winding by way of at least two electronic switches. On switching, both switches are opened for one or more time intervals in order to avoid current peaks.

Method for activating an asynchronous motor

The invention relates to a centrifugal pump assembly with an electric drive motor and with a control device having a frequency converter, for the control of the rotational speed of the drive motor, wherein the control device is designed in a manner such that in at least one control region, a field weakening is produced in the drive motor, by way of which the rotational speed of the drive motor is increased.

Centrifugal pump unit

A method for controlling the firing angle of a single-phase AC powered electric motor is provided which is triggered by at least one locking electronic switch, such as a triac (Tand T) located between the distribution voltage (U) and at least one motor winding (A, B). According to said method, intervals are defined within which the triacs (Tto T) are to be fired according to the curve of the distribution voltage (U) and the voltage (U) induced in the respective winding in order to allow the motor to start as quickly and smoothly as possible and run quietly and at high efficiency.

Method for controlling the firing angle of an electric motor

Disclosed is a method for controlling the firing angle of a signle-phase AC powered electric motor which is triggered by means of at least one locking electronic switch, especially a triac (Tand T) located between the distribution voltage (U) and at least one motor winding (A, B). According to said method, intervals are defined within which the triacs (Tto T) are to be fired according to the curve of the distribution voltage (U) and the voltage (U) induced in the respective winding in order to allow the motor to start as quickly and smoothly as possible and run quietly and at high efficiency.

A refrigerator or freezer includes a compressor with an electrical drive motor. The drive motor is activated by a rotational speed controller. The compressor is connected to a cooling medium circuit which contains a condenser, an evaporator and an expansion means arranged therebetween. The cooling device comprises a cooling space closable with a door as well as a temperature control for the cooling space. The rotational speed controller and the temperature control are grouped together to a constructional unit.

Cooling device

The method serves the commutation of an electrically commutated brushless, polyphase permanent magnet motor. The commutation angle, i.e. the angle from the zero crossing of the BEMF signal up to the reapplication of the voltage to the same winding is determined by the angle which results when the winding phase current has reached zero until the zero crossing of the BEMF signal.

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Bjerringbro, Denmark

Jan Caroe Aarestrup