Electric switch having an electromagnetic actuator

Patent metadata

Field	Value
Publication number	US-9870888-B2
Application number	US-201515306570-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Apr 29, 2014
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A method is disclosed for operating an electric switch having at least one movable switch contact, movable by a movable armature of an electromagnetic actuator to switch the switch on and off, a spring device arranged between the movable switch contact and the armature and, in order to move the armature from a starting position to an armature end position, a magnetic flux being generated in an exciter winding of the actuator by an exciter current being fed into the exciter winding. According to an embodiment and taking into account a position data set which specifies the respective armature position as a function of magnetomotive values and flux values, an armature position—called the contact strike armature position below—is determined at which the switch contacts meet each other during the closing operation, before the armature reaches the armature end position.

First claim

The invention claimed is:

1. A method for operating an electric switch including at least one movable switch contact configured to be moved by a movable armature of an electromagnetic actuator to switch the switch on and off, a spring device being disposed between the movable switch contact and the armature, and, in order to move the armature from a starting position, in which the switch contacts are open, into an armature end position, in which the switch contacts are closed and spring energy is stored in the spring device, a magnetic flux is to be generated in an excitation winding of the actuator via an excitation current being fed into the excitation winding, the method comprising:
determining the magnetic flux through the excitation winding or a flux variable correlating to the magnetic flux through the excitation winding, and forming a flux value;
determining the magnetomotive force in the excitation winding with consideration for at least the excitation current flowing through the excitation winding and a number of turns of the excitation winding, and forming a magnetomotive value; and
determining an armature position, with consideration for a position data set which indicates a particular armature position as a function of magnetomotive values and flux values, referred to as a contact strike armature position, at which the switch contacts meet each other during the closing operation, before the armature reaches the armature end position; and
regulating the magnetic flux through the excitation winding, to move the armature from the starting position into the end position.

2. The method of claim 1 , wherein the magnetic flux through the excitation winding is regulated to a constant setpoint flux, by way of a constant flux regulation, in the at least one time interval before the armature reaches the contact strike armature position.

3. The method of claim 2 , further comprising:
reading a magnetomotive value-armature position progression out of the position data set for the constant setpoint flux, the position progression indicating the armature position as a function of the magnetomotive force for the constant setpoint flux; and
determining the contact strike armature position at least also on the basis of the magnetomotive value-armature position progression.

4. The method of claim 3 , further comprising:
reading a strike magnetomotive value, at which the armature reaches the contact strike armature position, out of the position data set or the magnetomotive force-armature progression for the constant setpoint flux, wherein the determination of the contact strike armature position also takes place at least on the basis of the strike magnetomotive value.

5. The method of claim 2 , further comprising:
terminating the constant flux regulation or switching the constant flux regulation to another setpoint flux as soon as the armature reaches the contact strike armature position, by way of the magnetic flux being reduced by reducing the excitation current flowing through the excitation winding.

6. The method claim 2 ,
wherein the constant flux regulation is terminated or is switched to another setpoint flux as soon as the magnetomotive value is equal to the strike magnetomotive value.

7. The method of claim 1 , wherein the particular suitable or approximately suitable position value is read out of the position data set for the particular determined magnetomotive value and for the particular determined flux value, and wherein the contact strike armature position is detected on the basis of the position values.

8. The method of claim 1 , further comprising:
determining the progression of the movement of the armature from the position data set,
determining time-dependent position information, the time-dependent position information being used for determining time-dependent acceleration information, and
inferring that the contact strike armature position has been reached when the absolute value of the time-dependent acceleration information reaches or exceeds a threshold value.

9. The method of claim 1 , wherein the regulating of the magnetic flux through the excitation winding, to move the armature from the starting position into the end position, is done in such a way that the progression of the flux value, in at least one time interval before the armature reaches the contact strike armature position, has a fixed setpoint flux progression.

10. The method of claim 9 , wherein the magnetic flux through the excitation winding is regulated to a constant setpoint flux, by way of a constant flux regulation, in the at least one time interval before the armature reaches the contact strike armature position.

11. The method of claim 10 , further comprising:
reading a magnetomotive value-armature position progression out of the position data set for the constant setpoint flux, the position progression indicating the armature position as a function of the magnetomotive force for the constant setpoint flux, and
determining the contact strike armature position at least also on the basis of the magnetomotive value-armature position progression.

12. The method of claim 2 , further comprising:
reading a strike magnetomotive value, at which the armature reaches the contact strike armature position, out of the position data set or the magnetomotive force-armature progression for the constant setpoint flux, wherein the determination of the contact strike armature position also takes place at least on the basis of the strike magnetomotive value.

13. The method of claim 10 , further comprising:
reading a strike magnetomotive value, at which the armature reaches the contact strike armature position, out of the position data set or the magnetomotive force-armature progression for the constant setpoint flux, wherein the determination of the contact strike armature position also takes place at least on the basis of the strike magnetomotive value.

14. The method of claim 11 , further comprising:
reading a strike magnetomotive value, at which the armature reaches the contact strike armature position, out of the position data set or the magnetomotive force-armature progression for the constant setpoint flux, wherein the determination of the contact strike armature position also takes place at least on the basis of the strike magnetomotive value.

15. An electric switch comprising:
at least one movable switch contact, movable by a movable armature of an electromagnetic actuator to switch the switch on and off;
a spring device, disposed between the at least one movable switch contact and the movable armature, wherein a magnetic flux is generatable in an excitation winding of an actuator by way of an excitation current being fed into the excitation winding, to move the movable armature from a starting position in which the at least one movable switch contact and another switch contacts are open, into an armature end position, in which switch contacts, including the at least one movable switch contact and the another contact, are closed and spring energy is stored in the spring device; and
a control device to determines an armature position, referred to as a contact strike armature position, at which the switch contacts meet each other during the closing operation, before the armature reaches the armature end position,
determines the magnetic flux through the excitation winding or determines a flux variable correlating to the magnetic flux through the excitation winding, and form a flux value,
determines the magnetomotive force in the excitation winding with consideration for at least the excitation current flowing through the ex

Assignees

• Siemens Ag

Inventors

• Hahn Andreas
• Kuehn Wolfgang

Classifications

• H01H33/6662

  using bistable electromagnetic actuators, e.g. linear polarised electromagnetic actuators · CPC title

• H01F7/1844

  Monitoring or fail-safe circuits (for relays H01H47/002) · CPC title

• H01H47/04

  for holding armature in attracted position, e.g. when initial energising circuit is interrupted; for maintaining armature in attracted position, e.g. with reduced energising current {(with switching regulator H01H47/325)} · CPC title

• H01F2007/185

  with armature position measurement · CPC title

• H01H50/18

  Movable parts of magnetic circuits, e.g. armature · CPC title