Arrangement to monitor DC circuit condition

Patent metadata

Field	Value
Publication number	US-9645188-B2
Application number	US-201314058756-A
Country	US
Kind code	B2
Filing date	Oct 21, 2013
Priority date	Apr 21, 2011
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

An arrangement for monitoring a condition of a direct current voltage circuit including first and second supply poles for forming an operating voltage. A first fuse is connected to the first supply pole, and has a supply pole and an output pole. A second fuse is connected to the second supply pole, and has a supply pole and an output pole. The arrangement can form one or several reference voltages (U REF a,U REF b,U REF c), can form a first measurement voltage (U 1a ,U 1b ,U 1c ,U 1d ) between the output pole of the first fuse and the supply pole of the second fuse, and can form a second measurement voltage (U 1a ,U 1b ,U 1c ,U 1d ) between the output pole of the second fuse and the supply pole of the first or the second fuse. One or several reference voltages and measurement voltages can be compared to estimate a condition of the first and second fuse, and a comparison result can be indicated.

First claim

The invention claimed is:

1. An arrangement for monitoring a condition of a direct current voltage circuit, the arrangement comprising:
a first supply pole and a second supply pole for forming an operating voltage for the direct current voltage circuit;
a load connected between the first supply pole and the second supply pole;
a first fuse connected between the first supply pole and the load, which first fuse includes a input pole and an output pole;
a second fuse connected between the second supply pole and the load, which second fuse includes a input pole and an output pole;
means for forming one or several reference voltages (U REF a U REF b, U REF c);
means for forming a first measurement voltage (U 1a ,U 1b ,U 1c ,U 1d ) between the output pole of the first fuse and the input pole of the second fuse;
means for forming a second measurement voltage (U 1a ,U 1b ,U 1c ,U 1d ) between the output pole of the second fuse and the input pole of the first or second fuse;
means for comparing one or several reference voltages and measurement voltages to assess conditions of the first and the second fuses; and
means for indicating a result of the comparing.

2. An arrangement according to claim 1 , comprising:
means for forming one or several reference voltages and/or an auxiliary voltage of the direct current voltage circuit from an operating voltage between the first and the second supply poles.

3. An arrangement according to claim 1 , comprising:
one or several external power supplies for forming one or several reference voltages and/or an auxiliary voltage of the direct current voltage circuit.

4. An arrangement according to claim 1 , wherein the comparing means is configured to compare one reference voltage to the first and the second measurement voltages.

5. An arrangement according to claim 1 , wherein the means for forming reference voltages comprises:
means for forming a first reference voltage and means for forming a second reference voltage.

6. An arrangement according to claim 1 , wherein the comparing means comprise:
a first comparison unit to compare a first reference voltage to the first measurement voltage, and a second comparison unit to compare a second reference voltage to the second measurement voltage.

7. An arrangement according to claim 1 , comprising:
an auxiliary voltage source to create a reference voltage from an operating voltage or an external voltage source.

8. An arrangement according to claim 1 , comprising:
a constant current power source connection, which is connected in series with one or several auxiliary voltage supplies for forming the reference voltage and/or an auxiliary voltage and to limit an increase of power losses at a higher end of an operating voltage range.

9. An arrangement according to claim 1 , comprising:
a resistive connection, which is connected in series with one or several auxiliary voltage sources for forming the reference voltage and/or an auxiliary voltage.

10. An arrangement according to claim 1 , comprising:
one or several auxiliary voltage sources, connected in series with a constant current power source connection or resistive connection, and connected to the first and the second supply poles of the direct current voltage circuit.

11. An arrangement according to claim 1 , wherein the comparing means for forming the first measurement voltage and/or the second measurement voltage comprise:
a voltage divider circuit which includes one or several resistors.

12. An arrangement according to claim 1 , wherein the indicating means are arranged to indicate a fuse fault if one or several fuses are damaged.

13. An arrangement according to claim 1 , wherein the comparing means comprise:
a first linear comparator for monitoring a condition of the first fuse;
a second linear comparator for monitoring the condition of the second fuse; and
a logic circuit connected to the first and the second linear comparators, which logic circuit is arranged to indicate a faulty fuse when an output of one or several linear comparators indicates a faulty fuse.

14. An arrangement according to claim 1 , wherein the comparing means comprise:
a controller circuit equipped with an analogue-digital converter, arranged to compare one incoming reference voltage to the first and the second measurement voltages.

15. A method for monitoring a condition of a direct current voltage circuit, comprising:
forming an operating voltage of a direct current voltage circuit between a first supply pole and a second supply pole, a first fuse being connected between the first supply pole and a load, which first fuse has a input pole and an output pole, and a second fuse being connected between the second supply pole and a load, which second fuse has a input pole and an output pole;
forming one or several reference voltages (U REF a,U REF b,U REF c);
forming a first measurement voltage (U 1a ,U 1b ,U 1c ,U 1d ) between the output pole of the first fuse and the input pole of the second fuse;
forming a second measurement voltage between the output pole of the second fuse and the input pole of the first or the second fuse;
comparing one or several reference voltages and measurement voltages for estimating a condition of the first and second fuses; and
indicating a result of the comparing.

16. An arrangement according to claim 2 , comprising:
one or several external power supplies for forming one or several reference voltages and/or the auxiliary voltage of the direct current voltage circuit.

17. An arrangement according to claim 16 , wherein the comparing means is configured to compare one reference voltage to the first and the second measurement voltages.

18. An arrangement according to claim 17 , wherein the means for forming the reference voltage comprises:
means for forming a first reference voltage and means for forming a second reference voltage.

19. An arrangement according to claim 18 , wherein the comparing means comprise:
a first comparison unit to compare the first reference voltage to the first measurement voltage, and a second comparison unit to compare the second reference voltage to the second measurement voltage.

20. An arrangement according to claim 19 , comprising:
an auxiliary voltage source to create a reference voltage from an operating voltage or an external voltage source.

Assignees

• Abb Oy

Inventors

• Takala Marko
• Rajala Matti
• Pylkäs Marko

Classifications

• H01H2085/0266

  Structural association with a measurement device, e.g. a shunt · CPC title

• G01R31/74 Primary

  Testing of fuses · CPC title

• H02H3/046 Primary

  Signalling the blowing of a fuse (detecting non functioning of a lamp H05B47/20) · CPC title

• H01H85/32

  Indicating lamp structurally associated with the protective device · CPC title

• G01R31/07 Primary

  Physics · mapped topic