APPLIANCE HAVING A TEMPERATURE-MONITORED PLUG-IN CONNECTION

Abstract

An appliance includes an appliance interface forming a plug connection with an appliance-side interface unit of a power cable. The appliance interface includes at least one power contact part forming a power connection with a power contact part of the appliance-side interface unit supplying the appliance with electrical energy from a supply grid. The appliance interface includes a first thermoelectric element contacting a second thermoelectric element of the appliance-side interface unit, when the power connection exists. The first thermoelectric element is coupled to a first measurement input of a control unit. The appliance interface includes a measurement contact part forming a measurement connection, between the second thermoelectric element and a second measurement input of the control unit, with a measurement contact part of the appliance-side interface unit. The control unit determines measurement data relating to a measurement voltage between the first and second measurement inputs.

Claims

1-11. (canceled)

12. An appliance to be connected to a power cable, the appliance comprising: a control unit having a first measurement input and a second measurement input; an appliance interface configured to form a plug-in connection with an appliance-side interface unit of the power cable; said appliance interface including at least one power contact part configured to form a power connection with a power contact part of the appliance-side interface unit to supply the appliance with electrical energy from an electrical supply grid; said appliance interface including a first thermoelectric element configured to make contact with a second thermoelectric element of the appliance-side interface unit when said power connection exists; said first thermoelectric element being coupled to said first measurement input of said control unit; said appliance interface including a measurement contact part configured to form a measurement connection between the second thermoelectric element and said second measurement input of said control unit with a measurement contact part of the appliance-side interface unit; and said control unit being configured to determine measurement data relating to a measurement voltage between said first measurement input and said second measurement input.

13. The appliance according to claim 12, wherein: said first thermoelectric element includes a first material having a first thermoelectric coefficient; the second thermoelectric element and said measurement contact part of said appliance interface include a second material having a second thermoelectric coefficient; and the first thermoelectric coefficient and the second thermoelectric coefficient are different.

14. The appliance according to claim 12, which further comprises at least one of: a first line connecting said first thermoelectric element to the first measurement input of the control unit, said first thermoelectric element and said first line each including a first material; or a second line connecting said measurement contact part of said appliance interface to said second measurement input of said control unit, said measurement contact part of said appliance interface and said second line each including a second material.

15. The appliance according to claim 12, wherein said control unit is configured to initiate a measure relating to said power connection, based on the measurement data.

16. The appliance according to claim 15, wherein said measure relating to said power connection is a temperature of said power connection.

17. The appliance according to claim 15, which further comprises an output unit; said measure including at least one of: outputting an indication at said output unit relating to said power connection; or reducing a power consumption of the appliance through said power connection; or bringing the appliance into a safe operating state.

18. The appliance according to claim 12, wherein said first thermoelectric element is disposed on said power contact part of said appliance interface.

19. A system, comprising: an appliance according to claim 12; a grid-side interface unit; and a power cable including an appliance-side interface unit and lines connecting said appliance-side interface unit to said grid-side interface unit for connecting said power cable to an electrical supply grid; said appliance-side interface unit of said power cable including at least one power contact part configured to form a power connection with said power contact part of said appliance interface.

20. The system according to claim 18, wherein: said first thermoelectric element is disposed on said power contact part of said appliance interface; said appliance-side interface unit includes a second thermoelectric element configured to make contact with said first thermoelectric element when said power connection exists; and said appliance-side interface unit includes a measurement contact part being coupled to said second thermoelectric element and configured to form said measurement connection with said measurement contact part of said appliance interface.

21. The system according to claim 19, wherein said first thermoelectric element and said second thermoelectric element form a direct junction therebetween in a portion of said power connection between said power contact parts.

22. The system according to claim 19, wherein: said power contact part of said appliance interface includes a pin; and said power contact part of said appliance-side interface unit includes a receptacle into which said pin of said appliance interface can be plugged.

23. The system according to claim 19, wherein: said appliance-side interface unit includes a spring on which said second thermoelectric element is disposed; and said first thermoelectric element is disposed on a side of said power contact part of said appliance interface facing said spring of said appliance-side interface unit.

Description

[0025] In addition, the invention is described in greater detail below with reference to exemplary embodiments illustrated in the accompanying drawing, in which:

[0026] FIG. 1 shows a block diagram of a household appliance and of a power cable;

[0027] FIG. 2 shows an example of a plug-in system comprising means for determining information relating to a temperature of contact parts of the plug-in system: and

[0028] FIG. 3 shows an example of a plug-in connection comprising temperature monitoring.

[0029] As presented in the introduction, the present document is concerned with the reliable and precise monitoring of the temperature of a plug-in connection between a power cable and an electrical appliance, in particular a household appliance. FIG. 1 shows an appliance 100, in particular a household appliance, which can be connected via an appliance interface 102 (e.g. a plug) to the appliance-side interface unit 112 (e.g. a receptacle) of a power cable 110. The power cable 110 comprises electrical lines 113, which connect the appliance-side interface unit 112 to a grid-side interface unit 111. The appliance 100 comprises a control unit 101, which is designed to receive information relating to a plug-in connection between appliance-side interface unit 112 and appliance interface 102 from the appliance interface 102 (via one or more lines 215, 217). The control unit 101 is further designed to control the appliance 100 on the basis of the received information. For example, a visual and/or audible signal can be output via an output unit 103 of the household appliance 100 in order to inform a user of the appliance 100 about the temperature of the plug-in connection.

[0030] The plug-in connection between the appliance-side interface unit 112 and the appliance interface 102 can comprise means which can be used to acquire and indicate the temperature of the plug-in connection. FIG. 2 shows details of an example of a plug-in connection between an appliance 100 and a power cable 110. The plug-in connection is designed to make a plurality of power connections 211, 221, 231 in order to transfer electrical energy for supplying power to the appliance 100. In particular, a power connection 211 can be made for a neutral conductor N 210, a power connection 221 can be made for a phase conductor 220, and a power connection 231 can be made for a protective ground conductor 230. The appliance interface 102 and the appliance-side interface unit 112 each comprise contact parts for this purpose. In the example shown, the appliance interface 102 comprises pins or blades 212, 222, which can be plugged into corresponding receptacles 214, 224 of the appliance-side interface unit 112 in order to make the respective power connections 211, 221. The pins or blades 212, 222 and receptacles 214, 224 for making a power connection 211, 221 are referred to in this document in general as power contact parts.

[0031] An inadequate electrical contact made between the contact parts of a power connection 211, 221 can result in a higher transition resistance and hence a substantial rise in temperature at the contact parts. The plug-in connection shown in FIG. 2 comprises means for acquiring the temperature of a power connection 211, 221 in a precise manner. In particular, the power contact part 212, 222 of the appliance interface 102 comprises a first thermoelectric element 213, 223, and the appliance-side interface unit 112 (in particular the power contact part 214, 224 of the appliance-side interface unit 112) comprises a second thermoelectric element 219, 229, which are in contact with one another at the power connection 211, 221, or in the immediate vicinity of the power connection 211, 221, with the result that a voltage is produced because of the junction between the first thermoelectric element 213, 223 and the second thermoelectric element 219, 229, with the height of said voltage depending on the temperature at the junction between the first thermoelectric element 213, 223 and the second thermoelectric element 219, 229.

[0032] The first thermoelectric element 213, 223 is coupled via a first line 215, 225 to a first measurement input of the control unit 101. In addition, the second thermoelectric element 219, 229 is coupled to a second measurement input of the control unit 101 via a second line 218, 228 inside the appliance-side interface unit 112, via a second line 217, 227 inside the appliance interface 102, and via a signal connection 216, 226 between the second lines of the appliance-side interface unit 112 and of the appliance interface 102. A measurement voltage 201, 202 between the first measurement input and the second measurement input, which indicates the temperature of the junction between the first thermoelectric element 213, 223 and the second thermoelectric element 219, 229, can hence be acquired at the control unit 101.

[0033] The first thermoelectric element 213, 223 and the second thermoelectric element 219, 229 comprise different materials, in particular different metals, wherein the different materials have different thermoelectric coefficients k.sub.1 and k.sub.2 respectively. The measurement temperature T.sub.M at the junction typically is different from a reference temperature T.sub.R, wherein the reference temperature can be, for instance, the temperature at the measurement inputs of the control unit 101. The measurement voltage U.sub.M, which is acquired at the measurement inputs, is then given by:

U.sub.M=(k.sub.1k.sub.2)*(T.sub.MT.sub.R).

[0034] Thus if the thermoelectric coefficients and the reference temperature are known, the temperature can be acquired directly at a power connection 211, 221 in a precise manner on the basis of the measurement voltage. For this purpose, the first thermoelectric element 213, 223 and the first line 215, 225 are formed from the first material having the first thermoelectric coefficient k.sub.1. In addition for this purpose, the second thermoelectric element 219, 229, the second lines 218, 228 and 217, 227, and the signal connection 216, 226 are formed from the second material having the second thermoelectric coefficient k.sub.2.

[0035] The first thermoelectric element 213, 223 can be integrated in the power contact part 212, 222 of the appliance interface 102. For example, the first thermoelectric element 213 may be arranged, as shown in FIG. 3, for instance in portions on at least one power contact part 212 of the appliance interface 102. In a corresponding manner, the second thermoelectric element 219, 229 can also be arranged at least in portions on a power contact part 214, 224 of the appliance-side interface unit 112. The junction 311 between the first thermoelectric element 213, 223 and the second thermoelectric element 219, 229 can then lie in a specific portion of the power connection 211. FIG. 3 also shows a line 310 of the power cable 110 by way of example.

[0036] Thus a plug-in connection having a plurality of power connections 211, 221 is described, wherein at least one power connection 211, 221 comprises a thermocouple for determining temperature information relating to the temperature of the power connection 211, 221. The thermocouple for a power connection 211 comprises two different thermoelectric elements 213, 219, which form, for instance in a portion of the power connection 211, a junction 311 between each other. The thermoelectric voltage (i.e. the measurement voltage 201, 202) can be acquired via the measurement inputs of a control unit 101 (e.g. of a microcontroller). Then the control unit 101 can initiate on the basis of the measurement voltage 201, 202, one or more measures for reducing the temperature.

[0037] The first thermoelectric element 213 comprises a first material (e.g. iron, Fe) having a first thermoelectric coefficient. In addition, the first thermoelectric element 213 is coupled to the first measurement input of the control unit 101 via a first line 215, said first line 215 likewise comprising the first material. The second thermoelectric element 219 is coupled to the second measurement input of the control unit 101 via the second lines 217, 218 and via a plug-in connection 216 (for coupling the second lines 217, 218), wherein the second material (e.g. copper-nickel, CuNi) having the second thermoelectric coefficient is used in each case.

[0038] The measures described in this document can be used to monitor the temperature of a plug-in connection to a household appliance reliably and precisely. In this process, the temperature can be measured directly at a power connection 211, i.e. directly at the contact parts 212, 214 of a power connection 211. Moreover, the temperature measurement can take place during operation of an appliance 100. It is hence possible to prevent excessive heating of the plug-in connection. The described measures comprise galvanic isolation from the appliance power supply and hence can be implemented safely. The existence of a raised temperature of the plug-in connection can be indicated to a user at an output unit 103 of the appliance 100, so that the user can take suitable countermeasures. In addition, measures can be implemented promptly automatically in the appliance 100 in order to bring the appliance 100 into a safe operating state.

[0039] The present invention is not limited to the exemplary embodiments shown. In particular, it should be noted that the description and the figures are intended solely to illustrate the principle of the proposed appliance and/or system.