Low-voltage protective device

Patent metadata

Field	Value
Publication number	US-12548995-B2
Application number	US-202218689628-A
Country	US
Kind code	B2
Filing date	Sep 14, 2022
Priority date	Sep 20, 2021
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

For a low-voltage protective device, comprising: at least a first outer conductor path with a bypass switch, a first semiconductor circuit arrangement connected in parallel to the mechanical bypass switch, the first semiconductor circuit arrangement comprising at least one power semiconductor, at least a first voltage-dependent resistor is arranged in parallel with the bypass switch and the first semiconductor circuit arrangement, a control and driver unit configured to drive the first semiconductor circuit arrangement with a control voltage, it is suggested, that the low-voltage protective device comprises a voltage-detection-arrangement for detecting a voltage drop at the first voltage-dependent resistor and/or at least one temperature-detection-device to measure the temperature of the first voltage-dependent resistor at least before a switch on of the low-voltage protective device.

First claim

The invention claimed is:

1 . A protective device comprising:
at least a first outer conductor path from an outer conductor power supply connection of the protective device to an outer conductor load connection of the protective device; a neutral conductor path from a neutral conductor connection of the protective device connected to a neutral conductor load connection of the protective device, a mechanical bypass switch arranged in the first outer conductor path; a first semiconductor circuit arrangement of the protective device connected in parallel to the mechanical bypass switch, the first semiconductor circuit arrangement comprising at least one power semiconductor; at least a first voltage-dependent resistor is arranged in parallel with the bypass switch and the first semiconductor circuit arrangement; a control and driver unit configured to drive the first semiconductor circuit arrangement with a control voltage; a voltage-detection-arrangement configured to detect a voltage drop at the first voltage-dependent resistor; and at least one temperature-detection-device configured to measure a temperature of the first voltage-dependent-resistor at least before a switch on of the protective device, wherein the switch on of the protective device is configured to be carried out based on the voltage drop at the first voltage-dependent resistor and the measured temperature of the first voltage-dependent resistor.

2 . The low voltage-protective device according to according to claim 1 , wherein the voltage-detection-arrangement comprises a first voltage measuring device configured to measure a voltage between the first outer conductor path and the neutral conductor path, the first voltage measuring device being arranged between the outer conductor power supply connection and the mechanical bypass switch.

3 . The protective device according to claim 2 , wherein the voltage-detection-arrangement further comprises a second voltage measuring device, and wherein the second voltage measuring device is arranged between the mechanical bypass switch and the outer conductor load connection.

4 . The protective device according to claim 3 , wherein a first galvanic disconnector is arranged in the first outer conductor path between the first semiconductor circuit arrangement and the outer conductor load connection, and wherein the neutral conductor path further comprises a second galvanic disconnector.

5 . The protective device according to claim 4 , wherein the protective device further comprises at least a first snubber arrangement, and wherein the first snubber arrangement is arranged between the mechanical bypass switch and the outer conductor load connection.

6 . The protective device according to claim 5 , wherein the first snubber arrangement has at least a capacitor and at least a resistor, and the second voltage measuring device is connected in parallel to the capacitor.

7 . The protective device according to claim 5 , wherein the first snubber arrangement is arranged between the bypass mechanical switch and the first galvanic disconnector.

8 . The protective device according to claim 3 , wherein the voltage-detection-arrangement is configured to determine the voltage drop at the first voltage-dependent resistor by subtracting a second voltage measured by the second voltage measuring device from a first voltage measured by the first voltage measuring device.

9 . The protective device according to according to claim 8 , wherein the first voltage measuring device and the second voltage measuring device are connected to the control and driver unit, and wherein the subtraction of the second voltage from the first voltage is configured to be carried out by the control and driver unit.

10 . The protective device according to claim 1 , wherein the control and driver unit is configured to compare a temporal course of the voltage drop with at least one stored behavior of the voltage drop.

11 . The protective device according to claim 10 , wherein the switch on of the protective device is configured to be carried out if and only if the temporal course of the voltage drop fits within an expected value.

12 . The protective device according to claim 11 , wherein the expected value is within an expected range of the stored behavior of the voltage drop.

13 . The protective device according to claim 10 , wherein the switch on of the protective device is configured to be stopped based on the temporal course of the voltage drop not fitting within the expected value.

14 . The protective device according to claim 13 , the expected value is within the expected range of the stored behavior of the voltage drop.

15 . The protective device according to claim 1 , wherein the switch on of the protective device is configured to be carried out if and only if the measured temperature of the first voltage-dependent resistor is lower than a predefined temperature value.

16 . The protective device according to claim 1 , wherein the switch on of the protective device is configured to be stopped based on the measured temperature of the first voltage-dependent resistor being higher than a predefined temperature value.

17 . The protective device according to claim 1 , wherein the first voltage-dependent resistor is a varistor.

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Askan Kenan
• Schasfoort Peter

Classifications

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H01H2009/543

  third parallel branch comprising an energy absorber, e.g. MOV, PTC, Zener · CPC title

• H01H9/542 Primary

  Contacts shunted by static switch means · CPC title

• G01R31/327

  Testing of circuit interrupters, switches or circuit-breakers · CPC title

• H01H2009/546

  the static switching means being triggered by the voltage over the mechanical switch contacts · CPC title