Power distribution unit and fault detecting method

Patent metadata

Field	Value
Publication number	US-2017160761-A1
Application number	US-201615218090-A
Country	US
Kind code	A1
Filing date	Jul 25, 2016
Priority date	Dec 8, 2015
Publication date	Jun 8, 2017
Grant date	—

Abstract

A power distribution unit and a fault detecting method applied in the power distribution unit are disclosed herein. The power distribution unit includes an input terminal, an insulation fault detection circuit and a processing circuit. The input terminal is electrically coupled to a positive power line and a negative power line, and configured to receive a high voltage direct current (HVDC) voltage. The insulation fault detection circuit is configured to detect an insulation resistance value between a ground terminal and the positive power line or the negative power line. The processing circuit is configured to output a warning signal according to the insulation resistance value.

First claim

What is claimed is:

1 . A power distribution unit, comprising:
an input terminal, electrically coupled to a positive power line and a negative power line, and configured to receive a high voltage direct current voltage; an insulation fault detection circuit, configured to detect an insulation resistance value between the positive power line and a ground terminal, or between the negative power line and the ground terminal; and a processing circuit, configured to output a warning signal according to the insulation resistance value.

2 . The power distribution unit of claim 1 , further comprising:
at least one output branch, comprising:
an output terminal configured to output the high voltage direct current voltage; and
a leakage current detecting element configured to detect the current of the output branch and output a current detecting signal accordingly;
wherein the processing circuit is configured to output the corresponding warning signal according to the current detecting signal.

3 . The power distribution unit of claim 2 , wherein the at least one output branch further comprises:
an output switch configured to be turned off according to corresponding warning signal selectively such that the corresponding output terminal stops outputting the high voltage direct current voltage.

4 . The power distribution unit of claim 3 , wherein the processing circuit is further configured to output a control signal to the corresponding output switch according to the warning signal to turn off the output switch selectively.

5 . The power distribution unit of claim 2 , wherein the leakage current detecting element is configured to detect a first current flowing out from the corresponding output terminal and a second current flowing in to the corresponding output terminal, and output the current detecting signal according to the first current and the second current.

6 . The power distribution unit of claim 1 , wherein the insulation fault detection circuit is configured to output a first voltage signal and a second voltage signal corresponding to the insulation resistance value, and the processing circuit is configured to determine the insulation resistance value according to the first voltage signal and the second voltage signal.

7 . The power distribution unit of claim 6 , wherein the insulation fault detection circuit comprises:
a first switching element; a second switching element; a first resistor, electrically coupled to the positive power line and the ground terminal via the first switching element; a second resistor, electrically coupled to the negative power line and the ground terminal via the second switching element; a first voltage detecting element configured to measure the voltage across the first resistor and output the first voltage signal accordingly; and a second voltage detecting element configured to measure the voltage across the second resistor and output the second voltage signal accordingly.

8 . The power distribution unit of claim 7 , wherein the processing circuit is further configured to control the first switching element and the second switching element to be on or off, and calculate the insulation resistance value according to the value of the first voltage signal and of the second voltage signal measured when the first switching element is on and the second switching element is off, and measured when the first switching element is off and the second switching element is on.

9 . The power distribution unit of claim 7 , wherein the first switching element comprises a first switch and a third resistor electrically coupled in series, and the second switching element comprises a second switch and a fourth resistor electrically coupled in series.

10 . A power distribution unit, comprising:
an input terminal configured to receive a high voltage direct current voltage, wherein the input terminal comprises:
a positive node electrically coupled to a positive power line; and
a negative node electrically coupled to a negative power line;
at least one output branch, comprising:
an output terminal configured to output the high voltage direct current voltage; and
a leakage current detecting element configured to detect the current of the output branch and output a current detecting signal accordingly; and
a processing circuit configured to output a corresponding warning signal according to the current detecting signal.

11 . The power distribution unit of claim 10 , wherein the at least one output branch further comprises:
an output switch configured to be turned off selectively according to the corresponding warning signal such that the corresponding output terminal stops outputting the high voltage direct current voltage.

12 . The power distribution unit of claim 11 , wherein the processing circuit is further configured to output a control signal to the corresponding output switch according to the warning signal to turn off the output switch selectively.

13 . The power distribution unit of claim 10 , wherein the leakage current detecting element is configured to detect a first current flowing out from the corresponding output terminal and a second current flowing in to the corresponding output terminal, and output the current detecting signal according to the first current and the second current.

14 . The power distribution unit of claim 10 , further comprising:
an insulation fault detection circuit, electrically coupled to the positive power line and the negative power line, and configured to detect an insulation resistance value between the positive power line and a ground terminal, or between the negative power line and the ground terminal; wherein the processing circuit is electrically coupled to the insulation fault detection circuit and the leakage current detecting element, and the processing circuit is configured to output the corresponding warning signal according to the current detecting signal when the insulation resistance value is lower than a safety threshold value.

15 . The power distribution unit of claim 14 , wherein the insulation fault detection circuit is further configured to output a first voltage signal and a second voltage signal corresponding to the insulation resistance value, and the processing circuit is further configured to determine the insulation resistance value according to the first voltage signal and the second voltage signal.

16 . A fault detecting method applied in a power distribution unit, wherein the power distribution unit comprises an input terminal, an insulation fault detection circuit, and a processing circuit, and the fault detecting method comprises:
detecting, by the insulation fault detection circuit, an insulation resistance value between a ground terminal and a positive power line electrically coupled to the input terminal, or between the ground terminal and a negative power line electrically coupled to the input terminal; determining whether a grounding fault occurred in the power distribution unit according to the insulation resistance value; and outputting, by the processing circuit, a warning signal when the grounding fault occurred.

17 . The fault detecting method of claim 16 , wherein the power distribution unit further comprises at least one output branch, and the fault detecting method comprises:
detecting, by a leakage current detecting element, the current of the output branch and outputting a current detecting signal accordingly; determining, by the processing circuit, whether current leakage occurred in the output branch according to the cur

Assignees

• Delta Electronics Inc

Inventors

• Chan Chih-Chiang
• Li I-Chieh

Classifications

• G01R31/40

  Testing power supplies (testing photovoltaic devices H02S50/10) · CPC title

• G05B23/0275

  Fault isolation and identification, e.g. classify fault; estimate cause or root of failure · CPC title

• H02J1/06

  Two-wire DC power distribution systems · CPC title

• G05F1/66 Primary

  Regulating electric power · CPC title

• G01R27/18

  Measuring resistance to earth {, i.e. line to ground} · CPC title