Voltage monitoring module and voltage monitoring system

Patent metadata

Field	Value
Publication number	US-9470761-B2
Application number	US-201313888272-A
Country	US
Kind code	B2
Filing date	May 6, 2013
Priority date	May 30, 2012
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A voltage monitoring module includes voltage control circuits each connected between two adjacent input terminals and causing a current to flow to generate a voltage drop when a voltage of a k-th input terminal counted from a high potential side is higher than a voltage of a (k−1)-th input terminal; and a disconnection detection circuit that detects a disconnection between battery cells and m input terminals. The disconnection detection circuit includes an activation circuit that controls a flow of m currents flowing between the m input terminals and a ground terminal; (m−1) first switches having one end connected to each of second to m-th input terminals, and a control terminal connected to each of first to (m−1)-th input terminals, and turning on when a voltage applied to the control terminal is smaller than a predetermined value; and a memory unit connected to another end of the (m−1) first switches.

First claim

What is claimed is:

1. A voltage monitoring module comprising:
m (m is an integer equal to or greater than 2) input terminals respectively connected to high-potential-side terminals of m battery cells connected in series;
a ground terminal that receives a voltage of a low-potential-side terminal of a lowermost battery cell of the m battery cells;
(m−1) voltage control circuits that are each connected between two adjacent input terminals of the m input terminals and cause a current to flow to generate a predetermined voltage drop when a voltage of a k-th (k is an integer equal to or greater than 2 and equal to or less than m) input terminal counted from a high potential side is higher than a voltage of a (k−1)-th input terminal counted from the high potential side; and
a disconnection detection circuit that detects a disconnection between each of the high-potential-side terminals of the m battery cells connected in series and each of the m input terminals,
wherein the disconnection detection circuit comprises:
an activation circuit that is disposed between the m input terminals and the ground terminal and controls a flow of m currents flowing between each of the m input terminals and the ground terminal;
(m−1) first switches having first terminals respectively connected to the second to m-th input terminals counted from the high potential side; second terminals that output signals; and control terminals respectively connected to the first to (m−1)-th input terminals counted from the high potential side, the (m−1) first switches being configured to turn on when a voltage applied to the control terminals is smaller than a predetermined value; and
a memory unit connected to each of the second terminals of the (m−1) first switches.

2. The voltage monitoring module according to claim 1 , wherein the activation circuit causes the m currents flowing between each of the m input terminals and the ground terminal to collectively flow or to be interrupted.

3. The voltage monitoring module according to claim 1 , wherein the voltage control circuit comprises a diode having an anode connected to the k-th input terminal counted from the high potential side, and a cathode connected to the (k−1)-th input terminal counted from the high potential side.

4. The voltage monitoring module according to claim 1 , wherein the first switches comprise transistors each having a first terminal connected to the k-th input terminal counted from the high potential side, and a second terminal connected to the memory unit, a current flowing through the transistors when a voltage applied to the control terminals is smaller than a threshold voltage.

5. The voltage monitoring module according to claim 4 , wherein the disconnection detection circuit further comprises (m−1) first resistors connected between each of the (m−1) first switches and the ground terminal.

6. The voltage monitoring module according to claim 5 , wherein the second terminals of the first switches are connected to the ground terminal through any of the (m−1) first resistors.

7. The voltage monitoring module according to claim 1 , wherein the disconnection detection circuit further comprises a detection control circuit that controls an operation of controlling the flow of the m currents of the activation circuit.

8. The voltage monitoring module according to claim 7 , wherein the activation circuit comprises (m−1) second switches that are connected between each of the first to (m−1)-th input terminals counted from the high potential side and the ground terminal, and are configured to turn on/off with the same logic.

9. The voltage monitoring module according to claim 8 , wherein the second switches are transistors having one end connected to each of the first to (m−1)-th input terminals counted from the high potential side, and another end connected to the ground terminal, a current flowing through the transistors according to a voltage applied to control terminals of the transistors.

10. The voltage monitoring module according to claim 9 , wherein the activation circuit further comprises:
a first current source;
a first transistor that is cascade-connected to the first current source and operates with the same logic as that of the transistors constituting the (m−1) second switches; and
a second transistor connected between the control terminals of the transistors constituting the (m−1) second switches and the control terminal of the first transistor, and the ground terminal.

11. The voltage monitoring module according to claim 10 , wherein the detection control circuit outputs, to the activation circuit, a first control signal for controlling an operation of controlling the flow of the m currents of the activation circuit.

12. The voltage monitoring module according to claim 11 , wherein the first control signal is applied to a control terminal of the second transistor.

13. The voltage monitoring module according to claim 12 , wherein
the disconnection detection circuit further comprises:
a third switch having one end connected to the m-th input terminal counted from the high potential side;
a second resistor connected between another end of the third switch and the ground terminal;
a third transistor having one end connected to the m-th input terminal counted from the high potential side;
a fourth transistor connected between the m-th input terminal counted from the high potential side and the ground terminal; and
an inverter having an input connected to a node between the third switch and the second resistor, and an output connected to the memory unit, and

the activation circuit further comprises a fourth switch having one end connected to another end of the third transistor and the control terminals of the third and fourth transistors, and another end connected to the ground terminal, the fourth switch being configured to turn on/off with the same logic as that of the second switch.

14. The voltage monitoring module according to claim 13 , wherein the fourth switch comprises a transistor having a control terminal connected to the control terminal of the first transistor.

15. The voltage monitoring module according to claim 10 , wherein the activation circuit further comprises:
a second current source; and
a fifth switch that connects one of the first current source and the second current source to the first transistor according to a second control signal from the detection control circuit.

16. The voltage monitoring module according to claim 15 , wherein the second current source outputs a current to turn on the first switch when no disconnection occurs, upon connection of the second current source to the first transistor, between each of the high-potential-side terminals of the first to (m−1)-th battery cells counted from the high potential side and each of the first to (m−1)-th input terminals counted from the high potential side.

17. The voltage monitoring module according to claim 16 , wherein
the detection control circuit connects the second current source and the first transistor in a state where the second transistor is turned off, and
the disconnection detection circuit detects a failure of the disconnection detection circuit when a low-level signal is included in signals to be input to the memory unit from the second terminals of the (m−1) first switches.

18. The voltage monitoring module according to claim 13 , wherein the activation circuit further comprises:
a second current source; and
a fifth switch that connects one of the first current source and the second current source to the fi

Assignees

• Renesas Electronics Corp

Inventors

• Kiuchi Hideki

Classifications

• G01R31/392

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• G01R31/382

  Arrangements for monitoring battery or accumulator variables, e.g. SoC · CPC title

• G01R31/3835 Primary

  involving only voltage measurements · CPC title

• G01R31/396

  Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery · CPC title

• G01R31/3658

  Physics · mapped topic