Compensation device for compensating for leakage currents

Patent metadata

Field	Value
Publication number	US-11320494-B2
Application number	US-202016994748-A
Country	US
Kind code	B2
Filing date	Aug 17, 2020
Priority date	Aug 15, 2019
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A compensation device (20) for compensating for leakage currents has a differential current measuring device (22), a supply network detection device (42; 45), a control device (26), an amplifier (27), a compensation current selection device (36) and a feed-in device (39, 41). The supply network detection device (42; 45) generates a second signal (V_GRID; V_ES) characterizing the supply network (L1, L2, L3, N) connected to the active conductors (51, 52, 53, 54) and to supply it to the control device (26). The compensation current selection device (36) feeds in the compensation current (I_COMP) on the basis of a third signal (V_SEL) on at least one of the at least two different active conductors (51, 54), and the third signal (V_SEL) is dependent on the second signal (V_GRID; V_ES) to select at least one active conductor (51, 54) suitable for the connected supply network for the feed-in operation.

First claim

What is claimed is:

1. A compensation device for compensating for leakage currents, which compensation device has a differential current measuring device, a supply network detection device, a control device, an amplifier, a compensation current selection device and a feed-in device,
the differential current measuring device being designed to capture a first signal characterizing the differential current of the active conductors and to supply the first signal to the control device,
the supply network detection device being designed to generate a second signal characterizing the supply network connected to the active conductors and to supply the second signal to the control device,
the control device being designed to generate a compensation preset signal suitable for the compensation from the first signal and to supply the compensation preset signal to the amplifier,
the amplifier is designed to generate a compensation current on the basis of the compensation preset signal,
the feed-in device is designed to feed in the compensation current on at least two different active conductors,
the compensation current selection device is designed to feed in the compensation current on the basis of a third signal on at least one of the at least two different active conductors,
and the control device is designed to generate the third signal on the basis of the second signal to select at least one active conductor suitable for the connected supply network for the feed-in operation.

2. The compensation device of claim 1 , wherein the supply network detection device has at least one voltage measuring device and measures the voltage on at least one of the active conductors using the at least one voltage measuring device to detect the connected supply network.

3. The compensation device of claim 1 , further comprising a safety device, with a switch that is connected, on the input side, to a first line, the first line being connected to the amplifier, and the switch is designed to connect the first line either to a second line in a first state or to a third line in a second state, wherein the second line is connected to a protective conductor connection, the third line is connected to the compensation current selection device, and the switch can be controlled by the control device.

4. The compensation device of claim 3 , in which the switch is a relay.

5. The compensation device of claim 3 , in which the control device is designed to enable a functional test, during which functional test the control device controls the switch so that the switch is in the first state, and during the functional test the control device supplies a compensation preset signal to the amplifier, the preset signal causes a compensation current to check the function of the amplifier without feeding in the compensation current via the feed-in device.

6. The compensation device of claim 3 , wherein, before a supply network is connected to the active conductors, the control device changes the switch to the first state, and changes the switch to the second state only under predefined conditions that comprise the supply network being connected to the active conductors and the third signal being generated on the basis of the second signal.

7. The compensation device of claim 3 , wherein the first line is connected to the third line via a capacitor for transmitting pulses that occur on the third line, to the first line even in the first state of the switch.

8. The compensation device of claim 1 , further comprising a compensation current measuring device to measure the compensation current, to generate a fourth signal characterizing this compensation current and to supply the fourth signal to the control device.

9. The compensation device of claim 1 , which, if a supply network having a neutral conductor is detected by the supply network detection device, controls the compensation current selection device in such a manner that the compensation current is fed in by the feed-in device on that active conductor to which the neutral conductor is connected.

10. A vehicle comprising: a charging device for a load, the charging device having a rectifier and a load connected directly or indirectly to the rectifier, the load being coupled electrically to the active conductors, and the charging device having the compensation device of claim 1 , the load being a traction battery.

11. The vehicle of claim 10 , further comprising an EMC filter between the rectifier and the load.

Assignees

• Porsche Ag

Inventors

• Pfizenmaier Tim
• Spesser Daniel
• Mayer Florian

Classifications

• G01R31/52 Primary

  Testing for short-circuits, leakage current or ground faults · CPC title

• G01R31/002

  where the device under test is an electronic circuit · CPC title

• H02J3/00 Primary

  Circuit arrangements for AC mains or AC distribution networks · CPC title

• B60L3/0023

  Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train · CPC title

• H02J7/02

  for charging batteries from AC mains by converters · CPC title