Frequency regulation method and apparatus

Patent metadata

Field	Value
Publication number	US-11150284-B2
Application number	US-201816137126-A
Country	US
Kind code	B2
Filing date	Sep 20, 2018
Priority date	Mar 21, 2016
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

A frequency regulation method and apparatus is applied to an insulation impedance detection apparatus in a direct current power system, and relates to the field of security monitoring technologies of a direct current electrical system. The method includes: collecting sampling voltages at a sampling point for at least three time points; determining a voltage frequency regulation manner based on the sampling voltages, obtained through sampling, at the at least three time points; and then regulating a voltage frequency of a power supply according to the determined voltage frequency regulation manner. The voltage frequency of the power supply can be regulated based on the at least three sampling voltages obtained through sampling. Therefore, the insulation impedance detection apparatus reduces insulation impedance detection duration while ensuring accuracy of measured insulation impedance.

First claim

What is claimed is:

1. A frequency regulation method, applied to an insulation impedance detection apparatus in a direct current power system, comprising:
collecting sampling voltages at a sampling point for at least three time points;
determining a voltage frequency regulation manner based on the at least three sampling voltages; and
dynamically regulating a voltage frequency of a power supply in the insulation impedance detection apparatus according to the voltage frequency regulation manner to obtain a voltage cycle of the power supply equal to an insulation time constant of the insulation impedance detection apparatus.

2. The frequency regulation method of claim 1 , wherein determining the voltage frequency regulation manner based on the at least three sampling voltages comprises:
determining that the voltage frequency regulation manner is maintaining the voltage frequency unchanged when the at least three sampling voltages meet a first function relationship;
determining that the voltage frequency regulation manner is increasing the voltage frequency by a first step when the at least three sampling voltages do not meet the first function relationship but meet a second function relationship; or
determining that the voltage frequency regulation manner is reducing the voltage frequency by a second step when the at least three sampling voltages do not meet the first function relationship but meet a third function relationship.

3. The frequency regulation method according to of claim 2 , wherein the voltage cycle of the power supply in the insulation impedance detection apparatus is T, and wherein collecting sampling voltages at the sampling point for the at least three time points comprises:
collecting a first sampling voltage at a first sampling point at a time point zero of the voltage cycle, collecting a second sampling voltage at a second sampling point at a time point T/4 of the voltage cycle, and collecting a third sampling voltage at a third sampling point at a time point T/2 of the voltage cycle, or
collecting a first sampling voltage at a first sampling point at a time point T/2 of the voltage cycle, collecting a second sampling voltage at a second sampling point at a time point 3T/4 of the voltage cycle, and collecting a third sampling voltage at a third sampling point at a time point T of the voltage cycle.

4. The frequency regulation method of claim 3 , wherein the first function relationship is

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Assignees

• Huawei Tech Co Ltd

Inventors

• Yang Rui
• Wu Zhiwei
• Mo Wei

Classifications

• G01R27/025

  Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters · CPC title

• G01R27/04

  in circuits having distributed constants {, e.g. having very long conductors or involving high frequencies} · CPC title

• G01R35/005

  Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references (G01R33/0035, G01R35/002 take precedence) · CPC title

• G01R27/18 Primary

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

• G01R1/28

  Provision in measuring instruments for reference values, e.g. standard voltage, standard waveform · CPC title