Method and device for electrodynamic braking of a universal motor

Patent metadata

Field	Value
Publication number	US-10224838-B2
Application number	US-201314390086-A
Country	US
Kind code	B2
Filing date	Mar 5, 2013
Priority date	Apr 5, 2012
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

A method and device for electrodynamic braking of a universal motor. The method comprises the steps of continuously ascertaining a rotational speed of the universal motor, temporarily, periodically short-circuiting an armature of the universal motor with a semiconductor switch, and regulating firing angles of the semiconductor switch with a regulating device. The regulating device regulates firing angles of the semiconductor switch such that the rotational speed of the universal motor is adapted with minimal deviation to a rotational speed of a target rotational speed profile.

First claim

The invention claimed is:

1. A method for electrodynamic braking of a universal motor, comprising:
continuously ascertaining a rotational speed of the universal motor;
identifying a deviation between the rotational speed of the universal motor and a predetermined target speed of the universal motor;
generating a phase angle adjustment for operation of a semiconductor switch with a regulating device according to an indexed mapping of phase angles to a target rotational speed profile of the universal motor stored in a memory, wherein the generating of the phase angle adjustment includes jumping across multiple indices within the indexed mapping to determine the phase angle adjustment when the deviation exceeds a defined amount, and wherein the target rotational speed profile is based at least in part on a maximum loading of the universal motor; and
operating the semiconductor switch to generate periodic short-circuits in an armature of the universal motor at an adjusted phase angle corresponding to the phase angle adjustment being added to or subtracted from a predetermined phase angle for the universal motor to reduce the deviation between the rotational speed of the universal motor and the target speed.

2. The method as claimed in claim 1 , wherein the maximum loading has a maximum target rotational speed and a maximum moment of inertia for the universal motor.

3. The method as claimed in claim 1 , wherein the indexed mapping is configured as a table.

4. The method as claimed in claim 1 , wherein the indexed mapping is configured as a straight-line approximation.

5. A device for electrodynamic braking of a universal motor, comprising:
a rotational speed sensor configured to continuously ascertain a rotational speed of the universal motor;
a semiconductor switch configured to temporarily, periodically short-circuit an armature of the universal motor to brake the universal motor; and
a regulating device configured to:
identify a deviation between the rotational speed of the universal motor and a predetermined target speed of the universal motor;
generate a phase angle adjustment for operation of the semiconductor switch with the regulating device according to an indexed mapping of phase angles to a target rotational speed profile of the universal motor, wherein the generation includes jumping across multiple indices within the indexed mapping to determine the phase angle adjustment when the deviation exceeds a defined amount, and wherein the target rotational speed profile is based at least in part on a maximum loading of the universal motor; and
operate the semiconductor switch to generate periodic short-circuits in the armature of the universal motor an adjusted phase angle corresponding to the phase angle adjustment being added to or subtracted from a predetermined phase angle for the universal motor to reduce the deviation between the rotational speed of the universal motor and the target speed.

Assignees

• Bosch Gmbh Robert

Inventors

• Wiszniewski Jacek
• Pogorzelski Kamil

Classifications

• H02P6/08

  Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence) · CPC title

• H02P3/06 Primary

  for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter · CPC title

• H02P6/14

  Electronic commutators · CPC title

• H02P25/14

  Universal motors (H02P25/12 takes precedence) · CPC title

• H02P21/06

  Rotor flux based control involving the use of rotor position or rotor speed sensors · CPC title