Battery apparatus and battery management system for measuring insulation resistance
A first insulation resistance monitoring circuit includes a first resistor connected between a positive terminal of a battery pack and a node, and connected between the positive terminal of the battery pack and a ground terminal of an external device, and has a first monitoring terminal. A second insulation resistance monitoring circuit is connected between the ground terminal and the negative terminal of the battery pack, and has a second monitoring terminal. A voltage monitoring circuit is connected between the node and the negative terminal of the battery pack, and has a third monitoring terminal. A processor measures the voltage of the battery pack.
1 . A battery unit which is connectable to an external device, comprising:
a battery pack;
a first resistor connected between a positive terminal of the battery pack and a node, wherein a first electrical path extends from the node to a negative terminal of the battery pack and a second electrical path extends from the node to the negative terminal in parallel to the first electrical path;
a second resistor arranged to be connected between the node and a ground terminal of the external device positioned on the first electrical path, when the battery unit is connected to the external device;
a third resistor and a fourth resistor arranged to be connected between the ground terminal and the negative terminal of the battery pack positioned between the node and the ground terminal positioned on the first electrical path, when the battery unit is connected to the external device;
a fifth resistor connected between the node and the negative terminal of the battery pack positioned on the second electrical path; and
a processor configured to measure a voltage of the battery pack based on a voltage of a first terminal of the fifth resistor, and measure a first insulation resistance formed between the positive terminal of the battery pack and the ground terminal and a second insulation resistance formed between the negative terminal of the battery pack and the ground terminal based on a voltage of a first terminal of the second resistor and a voltage of a contact point of the third resistor and the fourth resistor.
2 . The battery unit of claim 1 , further comprising:
A DC voltage source arranged to be connected between the ground terminal and the negative terminal of the battery pack on the first electrical path.
3 . The battery unit of claim 1 , further comprising:
A first switch and a sixth resistor arranged to be connected between the node and the ground terminal on first electrical path;
A second switch arranged to be connected between the ground terminal and the negative terminal of the battery pack on the first electrical path; and
a seventh resistor connected between the node and the negative terminal of the battery pack on the second electrical path.
4 . The battery unit of claim 3 , further comprising:
a third switch connected between the node and the negative terminal of the battery pack on the second electrical path.
5 . The battery unit of claim 3 , wherein:
the processor is configured to perform the following:
measuring the voltage of the battery pack based on a voltage computed by dividing the voltage using resistances of the fifth resistor and the seventh resistor, when the first switch and the second switch are off; and
measuring the first insulation resistance and the second insulation resistance based on the voltage of the battery pack, a voltage computed by dividing the voltage using resistances of the second resistor and the sixth resistor when the first switch is on and the second switch are off, and a voltage computed by dividing the voltage using resistances of the third resistor and the fourth resistor when the first switch is off and the second switch are on.
6 . The battery unit of claim 1 , further comprising:
a first switch connected between the positive terminal of the battery pack and the node on the first electrical path;
a sixth resistor connected between the node and the ground terminal on the first electrical path;
a second switch arranged to be connected between the ground terminal and the negative terminal of the battery pack on the first electrical path; and
a seventh resistor connected between the node and the negative terminal of the battery pack on the second electrical path.
7 . The battery unit of claim 6 , further comprising:
a third switch connected between the node and the negative terminal of the battery pack on the second electrical path.
8 . The battery unit of claim 6 , wherein:
the processor performs the following:
measuring the voltage of the battery pack based on a voltage computed by dividing the voltage using resistances of the fifth resistor and the seventh resistor, when the first switch is on and the second switch is off; and
measuring the first insulation resistance and the second insulation resistance based on the voltage of the battery pack, a voltage computed by dividing the voltage using resistances of the second resistor and the sixth resistor when the first switch is on and the second switch is off, and a voltage computed by dividing the voltage using resistances of the third resistor and the fourth resistor when the first switch is off and the second switch is on.
9 . The battery unit of claim 1 , further comprising:
A first switch arranged to be connected between the node and the ground terminal on a path where the second resistor is positioned; and
A second switch arranged to be connected between the ground terminal and the negative terminal of the battery pack on a path where the third resistor and the fourth resistor are positioned.
10 . The battery unit of claim 9 , further comprising:
a third switch connected between the node and the negative terminal of the battery pack on a path where the fifth resistor is positioned.
11 . The battery unit of claim 9 , wherein:
The processor is configured to:
measure the voltage of the battery pack based on a voltage computed by dividing the voltage using resistances of the first resistor and the fifth resistor, when the first switch and the second switch are off; and
measure the first insulation resistance and the second insulation resistance based on the voltage of the battery pack, a voltage computed by dividing the voltage using resistances of the first resistor and the second resistor when the first switch is on and the second switch is off, and a voltage computed by dividing the voltage using resistances of the third resistor and the fourth resistor when the first switch is off and the second switch is on.
12 . A battery management system of a battery unit connectable to an external device and including a battery pack, comprising:
A first insulation resistance monitoring circuit that includes a first monitoring terminal, and a first resistor connected between a positive terminal of the battery pack and a node, and is arranged to be connected between the positive terminal of the battery pack and a ground terminal of the external device on a first electrical path, wherein the first electrical path extends from the node to a negative terminal of the battery pack and a second electrical path extends from the node to the negative terminal in parallel to the first electrical path;
A second insulation resistance monitoring circuit that includes a second monitoring terminal, and is arranged to be connected between the ground terminal and a negative terminal of the battery pack on the first electrical path;
a voltage monitoring circuit that includes a third monitoring terminal, and is connected between the node and the negative terminal of the battery pack on the second electrical path; and
a processor configured to measure a voltage of the battery pack based on a voltage of the third monitoring terminal, and measures a first insulation resistance formed between the positive terminal of the battery pack and the ground terminal and a second insulation resistance formed between the negative terminal of the battery pack and the ground terminal, based on a voltage of the first monitoring terminal and a voltage of the second monitoring terminal.
13 . The battery management system of claim 12 , wherein:
the first insulation resistance monitoring circuit further includes a first switch, a second resistor, and a third resistor connected between the node and the ground terminal on the first electrical path, and the first monitoring terminal being connected to a contact point of the second resistor and the third resistor, and
the second insulation resistance monitoring circuit further includes a DC voltage source, a second switch, a fourth resistor, and a fifth resistor connected between the ground terminal and the negative terminal of the battery pack on the first electrical path, and the second monitoring terminal being connected to a contact point of the fourth resistor and the fifth resistor, and
the voltage monitoring circuit further includes a sixth resistor and a seventh resistor connected between the node and the negative terminal of the battery pack on the second electrical path, and the third monitoring terminal being connected to a contact point of the sixth resistor and the seventh resistor.
14 . The battery management system of claim 13 , wherein:
the processor is configured to:
measure the voltage of the battery pack based on the voltage of the third monitoring terminal when the first switch and the second switch are off; and
measure the first insulation resistance and the second insulation resistance based on the voltage of the battery pack, the voltage of the first monitoring terminal measured when the first switch is on and the second switch is off, and the voltage of the second monitoring terminal measured when the first switch is off and the second switch is on.
15 . The battery management system of claim 12 , wherein:
the first insulation resistance monitoring circuit further includes a second resistor and a third resistor arranged to be connected between the node and the ground terminal, and a first switch connected between the positive terminal of the battery pack and the node on the first electrical path, the first monitoring terminal being connected to a contact point of the second resistor and the third resistor, and
the second insulation resistance monitoring circuit further includes a DC voltage source, a second switch, a fourth resistor, and a fifth resistor arranged to be connected between the ground terminal and the negative terminal of the battery pack on the first electrical path, the second monitoring terminal being connected to a contact point of the fourth resistor and the fifth resistor, and
the voltage monitoring circuit further includes a sixth resistor and a seventh resistor connected between the node and the negative terminal of the battery pack on the second electrical path, the third monitoring terminal being connected to a contact point of the sixth resistor and the seventh resistor.
16 . The battery management system of claim 15 , wherein:
the processor is configured to:
measuring the voltage of the battery pack based on the voltage of the third monitoring terminal, when the first switch is on and the second switch is off; and
measuring the first insulation resistance and the second insulation resistance based on the voltage of the battery pack, the voltage of the first monitoring terminal measured when the first switch is on and the second switch is off, and the voltage of the second monitoring terminal measured when the first switch is off and the second switch is on.
17 . The battery management system of claim 12 , wherein:
the first insulation resistance monitoring circuit further includes a first switch and a second resistor connected between the node and the ground terminal on the first electrical path, the first monitoring terminal being connected to a contact point of the first resistor and the second resistor, and
the second insulation resistance monitoring circuit further includes a DC voltage source, a second switch, a third resistor, and a fourth resistor connected between the ground terminal and the negative terminal of the battery pack on the first electrical path, the second monitoring terminal being connected to a contact point of the third resistor and the fourth resistor, and
the voltage monitoring circuit further includes a fifth resistor connected between the node and the negative terminal of the battery pack on the second electrical path, the third monitoring terminal being connected to a contact point of the first resistor and the fifth resistor.
18 . The battery management system of claim 17 , wherein:
the processor is configured to:
measure the voltage of the battery pack based on the voltage of the third monitoring terminal when the first switch and the second switch are off; and
measure the first insulation resistance and the second insulation resistance based on the voltage of the battery pack, the voltage of the first monitoring terminal measured when the first switch is on and the second switch is off, and the voltage of the second monitoring terminal measured when the first switch is off and the second switch is on.