VOLTAGE MONITORING MODULE AND VOLTAGE MONITORING SYSTEM

• US 20130335095A1
• Filed: 02/24/2012
• Published: 12/19/2013
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Kiuchi, Hideki
• Granted Patent: US 9,945,910 B2
• Time in Patent Office: Days
• US Class Current: 324/426
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The voltage monitoring module (100) includes an input terminal (V1), a cell balancing input terminal (VB1), a switch (SWa_—1), and a control circuit (CON). The input terminal (V1) is coupled to a high-voltage-side terminal of a battery cell (EC1) through a filter resistor (Rf). The cell balancing input terminal (VB1) is coupled to the high-voltage-side terminal of the battery cell (EC1). The switch (SWa_—1) is coupled to the input terminal (V1). The control circuit (CON) controls ON/OFF of the switch (SWa_—1). A filter resistor (C1) is coupled between the switch (SWa_—1) and a ground. The control circuit (CON) turns on the switch (SWa_—1), so that a high-voltage-side voltage (VH) is compared with a low-voltage-side voltage (VL).

Claims

1. A voltage monitoring module comprising:

a first input terminal coupled to a high-voltage-side terminal of a battery cell through an external resistor;

a first terminal coupled to the high-voltage-side terminal of the battery cell;

a first switch coupled to the first input terminal; and

a control circuit that controls ON/OFF of the first switch, wherein

an element that suppresses fluctuation of a voltage input to the first switch through the first input terminal is coupled between the first switch and a fixed voltage, and

the control circuit turns on the first switch, so that a first voltage output from the first input terminal through the first switch is compared with a second voltage output from the first terminal.

2. The voltage monitoring module according to claim 1, further comprising a second switch that is coupled to the first terminal, ON/OFF of the second switch being controlled by the control circuit,

wherein the control circuit turns on the first switch and the second switch, so that the first voltage is compared with the second voltage that is output from the first terminal through the second switch.

3. The voltage monitoring module according to claim 2, wherein the fixed voltage is lower than a voltage of the high-voltage-side terminal of the battery cell.

4. The voltage monitoring module according to claim 1, wherein the element that suppresses the fluctuation of the voltage input to the first switch comprises a capacitor coupled between a node between the first input terminal and the external resistor, and the fixed voltage.

5. The voltage monitoring module according to claim 3, wherein the element that suppresses the fluctuation of the voltage input to the first switch comprises a diode the cathode of which is coupled to a node between the first input terminal and the external resistor, and the anode of which is coupled to the fixed voltage.

6. The voltage monitoring module according to claim 3, wherein the element that suppresses the fluctuation of the voltage input to the first switch comprises a diode the cathode of which is coupled to a node between the first input terminal and the first switch, and the anode of which is coupled to the fixed voltage.

7. The voltage monitoring module according to claim 2, further comprising a comparator that compares the first voltage with the second voltage,

wherein a detection signal is output to outside according to an output of the comparator.

8. The voltage monitoring module according to claim 7, wherein the detection signal is output when a difference between the first voltage and the second voltage is equal to or greater than a predetermined value.

9. The voltage monitoring module according to claim 7, comprising:

a plurality of the first input terminals, the first terminals, the first and second switches; and

a plurality of the comparators that compare the first voltages output from the plurality of the first switches and the second voltages output from the plurality of the second switches, respectively,

wherein the detection signal is output when any of the outputs of the plurality of the comparators is high.

10. The voltage monitoring module according to claim 9, further comprising:

an OR circuit the input of which is coupled to the outputs of the plurality of the comparators outputs the detection signal from the output.

11. The voltage monitoring module according to claim 2, further comprising:

a second input terminal and a second terminal coupled to a low-voltage-side terminal of the battery cell;

a third switch coupled to the second input terminal, ON/OFF of the third switch being controlled by the control circuit; and

a fourth switch coupled to the second terminal, ON/OFF of the fourth switch being controlled by the control circuit,

wherein the control circuit turns on and turns off both the first switch and the third switch, and turns on and turns off both the second switch and the fourth switch, so that a third voltage that is a difference between the first voltage and a voltage output from the second input terminal through the third switch is compared with a fourth voltage that is a difference between the second voltage and a voltage output from the second terminal through the fourth switch.

12. A voltage monitoring system comprising:

the voltage monitoring module according to claim 11; and

a cell monitoring unit that monitors a voltage of the battery cell,

wherein the cell monitoring unit outputs a detection signal when the third voltage is different from the fourth voltage.

13. The voltage monitoring system according to claim 12, wherein the cell monitoring unit outputs the detection signal when a difference between the third voltage and the fourth voltage is equal to or greater than a predetermined value.