Control device for eliminating malfunctions in a network

Patent metadata

Field	Value
Publication number	US-9356544-B2
Application number	US-201314405319-A
Country	US
Kind code	B2
Filing date	May 8, 2013
Priority date	Jun 4, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Electrical malfunctions in a network which are caused by torque fluctuations of an electric motor, in particular flicker, are reduced by using a control device. For simple and cost-effective minimizing or even correction of such malfunctions with the control device, the control device has at least one first input for supplying an input signal which contains information suitable for determining the loading of the network by torque fluctuations and at least one output for transmitting an output signal to at least one converter supplying the electric motor. This makes it possible to reduce or ideally to eliminate electrical malfunctions in a network which are caused by torque fluctuation of the electric motor.

First claim

What is claimed is:

1. A method for eliminating electrical malfunctions in a network with a control device, the method comprising:
receiving with a controller of the control device at least one first input signal which is formed from a power signal that is generated from information obtained at an electric motor with a device for power determination,
receiving with the controller at least one additional input signal comprising mechanical information derived from the electric motor, wherein the mechanical information relates to at least one of a rotation speed and a rotor angle of the electric motor,
removing high-frequency components in the at least one first input signal by high-pass filtering,
forming from the at least one additional input signal relating to the rotation speed through integration a mechanical rotor angle,
multiplying auxiliary signals formed from sine and cosine values of the mechanical rotor angle and its multiples with the at least one high-pass-filtered first input signal,
integrating the multiplied auxiliary signals and multiplying the integrated multiplied auxiliary signals again with the auxiliary signals to form additional torque portions,
forming from the additional torque portions an additional torque target value,
generating with the controller from the additional torque target value at least one output signal of the control device,
superimposing a negative value of the additional torque target value onto a target torque to generate an overall target torque, and
supplying the overall target torque to a converter control system of a converter that is connected to a network and powers the electric motor.

2. The method of claim 1 , further comprising regulating a rotation speed of the electric motor based on an input signal representing an actual rotary speed signal from the electric motor and a target value representing a rotary speed target value for the electric motor, and generating as an output signal the target torque.

3. A control device for reducing electrical malfunctions in a network caused by torque fluctuations of at least one electric motor, the control device comprising:
at least one first input for receiving at least one first input signal which is formed from a power signal that is generated from information obtained at the electric motor with a device for power determination,
at least one additional input for receiving at least one additional input signal comprising mechanical information derived from the at least one electric motor, wherein the mechanical information relates to at least one of a rotation speed and a rotor angle of the electric motor, and
at least one output for outputting an output signal to at least one converter powering the electric motor for reducing the electrical malfunctions in the network caused by the torque fluctuations of the electric motor,
wherein the control device is configured to
remove high-frequency components in the at least one first input signal by high-pass filtering,
form from the at least one additional input signal relating to the rotation speed through integration a mechanical rotor angle,
multiply auxiliary signals formed from sine and cosine values of the mechanical rotor angle and its multiples with the at least one high-pass-filtered first input signal,
integrate the multiplied auxiliary signals and multiplying the integrated multiplied auxiliary signals again with the auxiliary signals to form additional torque portions,
form from the additional torque portions an additional torque target value,
generate from the additional torque target value at least one output signal of the control device,
superimpose a negative value of the additional torque target value onto a target torque to generate an overall target torque, and
supply the overall target torque as the output signal to the at least one converter.

4. A system having at least one electric motor powered by a converter and at least one control device, wherein the control device comprises
at least one first input for receiving at least one first input signal which is formed from a power signal that is generated from information obtained at the electric motor with a device for power determination,
at least one additional input for receiving at least one additional input signal comprising mechanical information derived from the at least one electric motor, wherein the mechanical information relates to at least one of a rotation speed and a rotor angle of the electric motor, and
at least one output for outputting an output signal to at least one converter powering the electric motor for reducing the electrical malfunctions in the network caused by the torque fluctuations of the electric motor,
wherein the control device is configured to
remove high-frequency components in the at least one first input signal by high-pass filtering,
form from the at least one additional input signal relating to the rotation speed through integration a mechanical rotor angle,
multiply auxiliary signals formed from sine and cosine values of the mechanical rotor angle and its multiples with the at least one high-pass-filtered first input signal,
integrate the multiplied auxiliary signals and multiplying the integrated multiplied auxiliary signals again with the auxiliary signals to form additional torque portions,
form from the additional torque portions an additional torque target value,
generate from the additional torque target value at least one output signal of the control device,
superimpose a negative value of the additional torque target value onto a target torque to generate an overall target torque, and
supply the overall target torque as the output signal to the at least one converter.

5. The system of claim 4 , further comprising at least one additional motor controller configured to regulate a rotation speed of the at least one electric motor, wherein the additional motor controller receives, for regulating the rotation speed of the at least one electric motor, as an input signal an actual rotary speed signal from the at least one electric motor and as a target value a rotary speed target value for the at least one electric motor, wherein the additional motor controller generates as output signal the target torque.

Assignees

• Siemens Ag

Inventors

• Brunotte Christoph

Classifications

• H02P23/04

  specially adapted for damping motor oscillations, e.g. for reducing hunting · CPC title

• H02J3/1835 Primary

  with stepless control · CPC title

• H02P6/10 Primary

  Arrangements for controlling torque ripple, e.g. providing reduced torque ripple · CPC title

• H02P27/06

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• Y02E40/30

  Reactive power compensation · CPC title