Electric leakage detection method

Patent metadata

Field	Value
Publication number	US-12078686-B2
Application number	US-202218059430-A
Country	US
Kind code	B2
Filing date	Nov 29, 2022
Priority date	Dec 1, 2021
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

The electric leakage detection method disclosed herein includes: total voltage measurement of measuring a total voltage V t which is an electrical potential difference between a total positive terminal open to be connectable with an external device and a total negative terminal open to be connectable with the external device; electric leakage voltage measurement of measuring an electric leakage voltage V L which is an electrical potential difference between a reference terminal (the total negative terminal) and the electric leakage occurring position (the third single battery); and an electric leakage occurring position determination of determining the electric leakage occurring position by calculating a ratio (V L /V t ) of the electric leakage voltage V L to the total voltage V t . This allows the number of single batteries between the reference terminal and the electric leakage occurring position to be estimated, and a detailed electric leakage occurring position to be determined.

First claim

What is claim is:

1. An electric leakage detection circuit configured to detect an electric leakage occurring position in a power source unit including multiple power sources electrically connected to each other, the electric leakage detection circuit comprising:
a reference terminal connected to a predetermined position of the power source unit;
an electric leakage voltage detection unit configured to calculate an electric leakage voltage V L which is an electrical potential difference between the reference terminal and the electric leakage occurring position; and
an electric leakage occurring position determination unit configured to determine the electric leakage occurring position based on the electric leakage voltage V L .

2. The electric leakage detection circuit according to claim 1 , further comprising:
a reference electrical potential difference detection unit configured to detect a reference electrical potential difference V S which is an electrical potential difference between a first terminal connected to the power source unit and a second terminal connected to the power source unit at a position with a different electrical potential from the first terminal, wherein
the electric leakage voltage detection unit is configured to
select either one of the first terminal or the second terminal as the reference terminal, and
calculate the electric leakage voltage V L , and

the electric leakage occurring position determination unit is configured to determine the electric leakage occurring position based on a ratio (V L /V S ) of the electric leakage voltage V L to the reference electrical potential difference V S .

3. The electric leakage detection circuit according to claim 2 , wherein
the reference electrical potential difference detection unit is connected between the first terminal and the second terminal; and
the electric leakage voltage detection unit is connected to the first terminal and the second terminal and connected to ground at a midpoint of the electric leakage voltage detection unit, and configured to detect
a first ground voltage V g(t1) corresponding to an electrical potential difference between the first terminal via the ground and the electric leakage occurring position, and
a second ground voltage V g(t2) corresponding to an electrical potential difference between the second terminal via the ground and the electric leakage occurring position.

4. The electric leakage detection circuit according to claim 3 , wherein
the electric leakage voltage detection unit includes:
a first switch connected to the first terminal side;
a first voltage detection resistor provided between the first switch and the midpoint;
a second switch connected to the second terminal side; and
a second voltage detection resistor provided between the second switch and the midpoint.

5. The electric leakage detection circuit according to claim 4 , wherein
the power source unit further includes:
a total positive terminal which is a positive electrode terminal open to be connectable with an external device; and
a total negative terminal which is a negative electrode terminal open to be connectable with the external device, and

the first terminal is connected to the total positive terminal, the second terminal is connected to the total negative terminal, and a total voltage V t of the power source unit, which is an electrical potential difference between the total positive terminal and the total negative terminal, is the reference electrical potential difference V S .

6. The electric leakage detection circuit according to claim 5 , wherein
the reference electrical potential difference detection unit is configured to measure a first total voltage V t(t1) while detecting the first ground voltage V g(t1) in the electric leakage voltage detection unit with the first switch ON and the second switch OFF;
the reference electrical potential difference detection unit is configured to measure a second total voltage V t(t2) while detecting the second ground voltage V g(t2) in the electric leakage voltage detection unit with the first switch OFF and the second switch ON; and
the electric leakage voltage detection unit is configured to calculate the electric leakage voltage V L based on the first ground voltage V g(t1) , the first total voltage V t(t1) , the second ground voltage V g(t2) , and the second total voltage V t(t2) .

7. The electric leakage detection circuit according to claim 6 , wherein
the electric leakage voltage V L at timing (t) is calculated based on equation (1)

V
L

(
t
)

=

k
⁢

V
t

(
t
)

(
1
)

[

equation
⁢

2

]



k
=

V
t

(

t
1

)

V
t

(

t

2

)

V
g

(

t
1

)

V
g

(

t
2

)

+

Assignees

• Prime Planet Energy & Solutions Inc

Inventors

• Furukawa Kimihiko
• Yano Junya

Classifications

• G01R31/40

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

• G01R31/52 Primary

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

• G01R31/007

  using microprocessors or computers · CPC title

• G01R19/16542

  for batteries (charge condition monitoring in G01R31/36) · CPC title

• G01R31/3842

  combining voltage and current measurements · CPC title