FI110371B - Procedures and devices for reducing synchronous machine torque vibrations - Google Patents

Description

1 110371

METHOD AND EQUIPMENT FOR REDUCING TORQUE VOICE VIBRATIONS

The invention relates to a method according to the preamble of claim 1 and to an apparatus according to the preamble of claim 5.

The AC machine torque is generated by the magnetization of the anchor circuit, normally the stator, the supply voltage and the magnetization circuit, normally the rotor. The supply voltage is applied to the stator windings which are arranged in the grooves of the stator 10. The magnetization is developed by the fitted permanent magnets of the rotor or by the magnetization coils arranged on the rotor. Torque uniformity is influenced by how close the field developed to the engine air gap is sinusoidal. The non-sinusoidal waveform produces moments at a frequency determined by the harsh components contained therein that cause mechanical vibration and noise.

The shape of the air gap field is influenced not only by the frequency of the supply voltage, but also by the shape of the field caused by the magnetization.

\ t A permanent magnet synchronous machine is characterized by a so-called "cogging" V. 20, which is caused by stator teeth • · • · · ,; of this reluctance variation, the angle of the rotor and stator ί! angle.

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The object of the invention is to provide a solution which substantially reduces the vibration and noise caused by the harmonic moments of the motor. To accomplish this, the method according to the invention is characterized by the features of claim 1. Correspondingly, the apparatus according to the invention is characterized by the features of the patent claim 5 of the patent claim. The features of some preferred embodiments of the invention will be apparent from the dependent claims.

The invention relates to a method of reducing the torque ripple of a motor controlled by a torque controller by summing a correction signal dependent on the angle between the rotor and the stator to the input of the torque controller.

2 110371

According to the most preferred embodiment of the present invention, the frequency of the correction signal is the same as the track frequency and its phase is locked in the rotor angle. Preferably, the locking steps and the amplitude form two parameters that are either kept constant during travel or made adjustable according to the operating point.

According to a preferred embodiment, the signal processing circuit comprises a memory member for reading the correction torque component. Preferably, the memory component is formed by first driving the motor without a correction signal and simultaneously measuring the resulting torque rupture component. In normal motor operation, the corresponding signal in reverse phase is summed to the torque reference. The torque ripple is then compensated.

According to a further embodiment, the correction signal is generated by the neural network included in the signal editor.

In particular, the solution according to the invention can advantageously and reliably eliminate the torque ripple caused by the groove harmonics of a permanent magnetized axial air gap motor. A particular application is an elevator drive motor.

The invention will now be described, by way of example, with reference to the figure illustrating the invention: 1. engine adjuster.

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The motor 2 is controlled by a torque adjuster 4. The angle information between the motor static 25 and the rotor is measured by the angular measuring apparatus · · · and the motor speed is measured by the velocity measuring apparatus 8 connected to the axis of the motor 2. No- ···, the velocity information 28 is provided to the differential element 18, which is also provided with a velocity reference 20. The velocity reference and velocity measurement control the no-30 velocity adjuster 12 in a manner known per se. The output of the speed controller i '. · Is applied to an adder 14, which also provides a correction signal 22 according to the invention. The output of the adder 14 is applied to a torque controller 4 which controls the motor.

3 110371

The angle measurement information (16,26) is applied to the torque adjuster 4 and to the signal modifier 10. In the signal modifier 10, a correction signal 22 is formed to be added to the adder 14 and added to the torque reference. According to the figure, also the speed signal 5 is applied to the signal converter 10.

According to a preferred embodiment, the signal editor has memory means on which the correction signal is stored. By running the motor without a correction signal, a torque ripple can be measured and the corresponding signal is stored in memory. In Nor-10 targets, the corresponding signal in reverse phase is applied to the adder. Of course, the correction signal generated in the above manner can also be stored in the memory as such.

According to one embodiment, the frequency of the correction signal is the same as the track frequency of the motor and its phase is locked at the angle of the rotor-15. Phase and amplitude are two parameters that are either kept constant during driving or made adjustable according to the operating point. The parameters are suitably stored in the memory.

The invention has been described above with the aid of some embodiments thereof. However, the disclosure is not to be construed as limiting the scope of the patent, but various embodiments may vary within the scope of the following claims.

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Claims (5)

4, 110371 A method for reducing the torque ripple of a motor controlled by a torque regulator by summing a correction signal depending on the angle between the rotor and the stator to the input of the torque regulator, characterized in that the frequency of the correction signal is equal to the track frequency of the motor A method according to claim 1, characterized in that the correction signal is formed by first driving the motor without a correction signal while measuring the resulting torque rupture component which is stored in the memory element, and in the normal driving mode 15 3. Method according to claim 1 or 2, characterized in that the correction signal is generated by a neural network. Method according to claim 1, characterized in that the phase and the amplitude form two parameters which *. either kept constant during driving or made adjustable to function, V.20. »I • · • · 5. Apparatus for reducing the torque * 1 ripple of a motor controlled by a torque regulator to include a signal modifier capable of generating a torque ripple::: eliminating a correction signal that can be summed to a torque regulator input and generating a correction signal in a • 1: signal modifier angle between stator and rotor ··. by means of information, characterized in that the apparatus includes a memory track in which the motor-frequency and phase-corrected correction signal locked to the rotor angle or the aforesaid correction signal to the above-mentioned 30 signal can be stored in: 1 · 1 . 110371