PM line-start motor and switch-on method therefor
AssigneeKSB SE & Co. KGaA
InventorsGerhard Huth, Hans-Georg Schirmer
Life of this patent
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Abstract
A PM line-start motor, preferably motors having a power of at least 5 kW, and a switch-on method therefor are provided. The motor includes a rotor and a stator having a stator winding designed as a pole-reversible rotary field winding. With the aid of the pole-reversible rotary field winding, the regenerative braking torque generated during the asynchronous high-run operation can be avoided, preferably by use of a sequence controller to control the changeover of the pole-reversible rotary field winding in the run-up phase.
Claims13
A PM line-start motor, comprising:
- a rotor;
- and
- a stator having a stator winding,
- wherein the stator winding is a changeable-pole rotating field winding,
- wherein
- the changeable-pole rotating field winding includes a first winding stage and a second winding stage operable separately from one another,
- a number of start-up pole pairs p1 of the first winding stage differs from a number of operating pole pairs p2 of the second winding stage,
- the first winding stage is configured for asynchronous run-up of the motor and the second winding stage is configured for synchronous operation of the motor,
- the number of start-up pole pairs p1 of the first winding stage differs from a number of poles p3 of the PM rotor, and
- the number of operating pole pairs p2 of the second winding stage is the same as the number of poles p3 of the PM rotor.
A switch-on method of a PM line-start motor which includes a rotor, a stator having a stator winding which is a changeable-pole rotating field winding, a sequence controller configured to perform a targeted winding changeover of the changeable-pole rotating field winding during a switch-on process of the motor in which the first winding stage is for run-up of the motor to the second winding stage is for synchronous operation of the motor, the sequence controller further being configured to provide a phase between the changeover from the first winding stage to the second winding stage in which neither the first nor the second winding stage is supplied with power, the time of the changeover to the second winding stage depends on a phasing of a supply system voltage, comprising the steps of:
- switching on the first winding stage to start an asynchronous run-up phase;
- disconnecting the first winding stage to terminate the asynchronous run-up phase;
- and
- switching on the second winding stage to start synchronous operation of the motor.
Dependencies are inferred from the claim text.