Method for controlling excitation energy in a coil arrangement of a flow measuring device embodied as a two-conductor field device

Patent metadata

Field	Value
Publication number	US-9341506-B2
Application number	US-201314405453-A
Country	US
Kind code	B2
Filing date	May 21, 2013
Priority date	Jun 12, 2012
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A method for controlling excitation energy in a coil arrangement of a flow measuring device having an energy buffer system for storing energy and embodied as a two-conductor field device is provided for producing a magnetic field B passing through a medium as a function of the excitation energy. The wherein the flow measuring device has a plurality of operating states, between which it transfers and which describe an excitation current pulsed in a time interval. At least a first operating state is operated with a first power, in which the coil arrangement in a first period is excited with an excitation current with a first maximum electrical current level, wherein the period additionally has a first pulse pause, wherein the method is characterized by steps as follows: storing a fed-in excess power, which is beyond a minimum power for operating the device, for operating the coil arrangement during a period as a function of the supplied power in an energy buffer system; wherein an at least partial charging of the energy buffer system occurs in the first pulse pause and an at least partial discharging of the energy buffer system occurs during the excitation of the electrical current level; and changing into a second operating state, in which the coil arrangement is excited in a second period with an excitation current, wherein the second period has a second pulse pause, which is shorter than the first pulse pause.

First claim

The invention claimed is:

1. A method for controlling excitation energy in a coil arrangement of a flow measuring device having an energy buffer system for storing energy and embodied as a two-conductor field device for producing a magnetic field B passing through a medium as a function of the excitation energy, wherein the flow measuring device has a plurality of operating states, between which it transfers and which describe an excitation current pulsed in a time interval, wherein at least a first operating state is operated with a first power, in which the coil arrangement in a first period is excited with an excitation current with a first maximum electrical current level, wherein the period additionally has a first pulse pause, wherein the method comprising the steps of:
A) storing a fed-in excess power, which is beyond a minimum power for operating the device, for operating the coil arrangement during a period as a function of the supplied power in an energy buffer system; wherein an at least partial charging of the energy buffer system occurs in the first pulse pause and an at least partial discharging of the energy buffer system occurs during the excitation of the electrical current level; and
B) changing into a second operating state, in which the coil arrangement is excited in a second period with an excitation current, wherein the second period has a second pulse pause, which is shorter than the first pulse pause.

2. The method as claimed in claim 1 , wherein:
the flow measuring device changes between two operating states as a function of the charge status of the energy buffer system.

3. The method as claimed in claim 1 , wherein:
a capacitor is used as energy buffer system.

4. The method as claimed in claim 1 , wherein:
control of the excitation energy occurs independently of a terminal voltage and/or terminal current lying on the flow measuring device.

5. The method as claimed in claim 1 , wherein:
the second operating state enables production of a continuously pulsed excitation current with a second pulse pause of zero.

6. The method as claimed in claim 1 , wherein:
the energy buffer system is integrated into the housing of the flow measuring device, preferably a magneto inductive or a Coriolis flow measuring device.

7. The method as claimed in claim 1 , wherein:
the energy buffer system has a minimum storage capacity of 20 mJ, preferably for an electrical current level of 0-30 mA.

8. The method as claimed in claim 1 , wherein:
in the second operating state the coil arrangement is excited in a second period with an excitation current with the first maximum electrical current level.

9. The method as claimed in claim 1 , wherein:
in the second operating state the coil arrangement is excited in a second period with an excitation current with a second maximum electrical current level; and
the second maximum electrical current level is greater than the first maximum electrical current level.

10. The method as claimed in claim 1 , wherein:
the second pulse pause is zero.

Assignees

• Flowtec Ag

Inventors

• Spahlinger Andre
• Kung Thomas
• Rufenacht Markus

Classifications

• G01F1/60 Primary

  Circuits therefor · CPC title

• G01F1/56 Primary

  by using electric or magnetic effects (G01F1/66 takes precedence) · CPC title

• G01F1/84

  Coriolis or gyroscopic mass flowmeters · CPC title