Impedance measurement device

Patent metadata

Field	Value
Publication number	US-12535531-B2
Application number	US-202218563141-A
Country	US
Kind code	B2
Filing date	Mar 25, 2022
Priority date	May 24, 2021
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A signal injection unit configured to inject an AC signal to an target injection line to which a battery is connected in series, a non-contact-type current sensor that detects a current value of the AC signal flowing through the target injection line in a non-contact manner with respect to the target injection line and outputs a detection signal, a voltage detection unit that detects a voltage value of an AC voltage generated at ends of the battery by being in contact with the ends and outputs an end-to-end voltage signal, and a processing unit that measures an internal impedance of the battery on the basis of the detection signal and the end-to-end voltage signal. The signal injection unit is configured to inject the AC signal to the target injection line in a non-contact manner.

First claim

The invention claimed is:

1 . An impedance measurement device comprising:
a signal injection unit configured to generate an AC signal for measurement and inject the AC signal to a target injection line to which a measurement target is connected in series; a non-contact-type current detection unit configured to detect a current value of the AC signal flowing through the target injection line in a non-contact manner with respect to the target injection line, and output a current detection signal; a voltage detection unit configured to detect a voltage value of the AC voltage generated at ends of the measurement target by being in contact with the ends, and output a voltage detection signal; and a processing unit configured to receive input of the current detection signal and the voltage detection signal and measure an impedance of the measurement target on the basis of the current detection signal and the voltage detection signal, wherein the signal injection unit is configured to inject the AC signal to the target injection line in a non-contact manner.

2 . The impedance measurement device according to claim 1 , wherein the voltage detection unit includes an insulating circuit configured to output the detected voltage detection signal to the processing unit in a state where the voltage detection unit is insulated from the measurement target.

3 . The impedance measurement device according to claim 1 ,
wherein the processing unit includes a first quadrature detection circuit configured to receive input of the AC signal, perform quadrature detection on the current detection signal, and generate an in-phase component and a quadrature component of the AC current, a second quadrature detection circuit configured to receive input of the AC signal, perform quadrature detection on the voltage detection signal, and generate an in-phase component and a quadrature component of the AC voltage, and an arithmetic circuit configured to compute the impedance of the measurement target on the basis of the in-phase component and the quadrature component of the AC current output from the first quadrature detection circuit and the in-phase component and the quadrature component of the AC voltage output from the second quadrature detection circuit.

4 . The impedance measurement device according to claim 1 , wherein the signal injection unit includes a primary winding component constituting a primary winding to be magnetically coupled to the target injection line as a secondary winding, the signal injection unit injecting the AC signal to the target injection line by applying the AC signal to the primary winding component.

5 . The impedance measurement device according to claim 4 , wherein the primary winding component includes an insulated coated wire wound around a first magnetic core, the first magnetic core having an annular shape and being configured to receive insertion of the target injection line.

6 . The impedance measurement device according to claim 5 , wherein the first magnetic core is provided with gaps.

7 . The impedance measurement device according to claim 6 , wherein
the first magnetic core is configured of a plurality of C-type unit magnetic cores, and the plurality of unit magnetic cores overlap each other such that a separation distance between two of the gaps being mutually adjacent is equal along an outer periphery of the first magnetic core in a top view in an overlapping state.

8 . The impedance measurement device according to claim 5 , wherein
the primary winding component includes Na windings from a first winding to an Na-th winding (Na is an integer greater than or equal to two) that are configured of the insulated coated wires wound around the first magnetic core and are connected in series as a whole, and Na switches from a first parallel switch to an Na-th parallel switch that are connected in parallel to the first winding to the Na-th winding, respectively, and the processing unit performs ON/OFF control on the Na parallel switches to change the number of turns of the primary winding component overall.

9 . The impedance measurement device according to claim 8 , wherein each of the first winding to the Na-th winding is wound such that the numbers of turns are different from each other.

10 . The impedance measurement device according to claim 9 , wherein each of the first winding to the Na-th winding is wound a number of times obtained by multiplying 2 Ma (Ma denotes Na integers from 0 to (Na−1)) by La being an integer greater than or equal to 1.

11 . The impedance measurement device according to claim 9 , wherein the first winding to the Na-th winding are formed such that wire diameters of core wires in the insulated coated wires of windings with larger numbers of turns are thinner than wire diameters of core wires in the insulated coated wires of windings with smaller numbers of turns.

12 . The impedance measurement device according to claim 8 , comprising:
a signal detection unit configured to detect a current value of the AC signal flowing through the target injection line, wherein the processing unit performs ON/OFF control on the first parallel switch to the Na-th parallel switch such that a current value of the AC signal detected by the signal detection unit is within the target current value range.

13 . The impedance measurement device according to claim 8 , comprising:
a signal detection unit configured to detect a current value of the AC signal flowing through the target injection line, wherein the processing unit determines a load impedance of the target injection line and performs ON/OFF control on the first parallel switch to the Na-th parallel switch on the basis of a current value of the AC signal injected by the signal injection unit to the target injection line and a current value of the AC signal detected by the signal detection unit, to thereby increase the number of turns of the primary winding component overall when the determined load impedance is small or decrease the number of turns of the primary winding component overall when the determined load impedance is large.

14 . The impedance measurement device according to claim 5 , wherein
the signal injection unit includes a plurality of the primary winding components made to correspond to a plurality of frequency band groups grouped from a frequency band of the AC signal to be generated, respectively, and when injecting the AC signal of a frequency belonging to one frequency band group of the plurality of frequency band groups, the signal injection unit applies the AC signal to ends of the primary winding component corresponding to the one frequency band group, the frequency band is grouped into two frequency band groups,
the first magnetic core in the primary winding component made to correspond to a frequency band group on a low frequency band side of the two frequency band groups is configured of a metal-based magnetic core, and
the first magnetic core in the primary winding component made to correspond to a frequency band group on a high frequency band side of the two frequency band groups is configured of a ferrite-based magnetic core.

15 . The impedance measurement device according to claim 14 , wherein the signal injection unit is configured to change a frequency of the AC signal, and applies the AC signal to two of the primary winding components corresponding to two frequency band groups of the plurality of frequency band groups when changing the frequency of the AC signal from one of the two frequency band groups to another of the two frequency band groups at a boundary portio

Assignees

• Hioki Electric Works

Inventors

• Hotta Akinori
• Toya Hiroyuki
• Ikeda Hiroyoshi
• Kasai Shin
• Sakai Tomoharu
• Tsukioka Yasuyuki
• Yanagisawa Koichi

Classifications

• G01R31/386

  using test-loads · CPC title

• G01R27/16

  Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line · CPC title

• G01R15/18

  using inductive devices, e.g. transformers · CPC title

• G01R31/389 Primary

  Measuring internal impedance, internal conductance or related variables · CPC title

• G01R27/02

  Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant (by measuring phase angle only G01R25/00) · CPC title