Systems and methods for measuring isolation resistance
First Claim
1. An energy storage system configured to output at least two voltage waveforms, comprising:
- a semiconductor relay switch;
one or more battery packs, wherein one terminal of the one or more battery packs of the energy storage system is electrically coupled to a resistor of a plurality of resistors, wherein the plurality of resistors is configured to electrically couple to the one or more battery packs via the semiconductor relay switch;
a gain field-effect transistor (FET) configured to electrically short at least one resistor of the plurality of resistors, wherein the at least one resistor of the plurality of resistors is directly coupled to a voltage output terminal configured to output the at least two voltage waveforms for determining an isolation resistance of the energy storage system; and
a control system configured to;
send a first command to the semiconductor switch to close;
acquire a first voltage waveform corresponding to a first voltage measurement over a first period of time at the voltage output terminal after the first command has been sent;
send a second command to the semiconductor switch to open;
send a third command to the gain FET to close after the second command has been sent, wherein the at least one resistor of the plurality of resistors is electrically shorted when the gain FET is closed;
send a fourth command to the semiconductor switch to close after the third command has been sent;
acquire a second voltage waveform corresponding to a second voltage measurement over a second period of time at the voltage output terminal after the fourth command has been sent; and
determine the isolation resistance based at least in part on a Thevenin equivalent resistance calculated from the first voltage waveform and the second voltage waveform.
5 Assignments
0 Petitions
Accused Products
Abstract
An energy storage system may include battery packs, such that one terminal of the battery packs is electrically coupled to a resistor representative of an isolation resistance of the battery system. The system may include a semiconductor relay switch, a plurality of resistors configured to electrically couple to the battery packs via the semiconductor relay switch, a gain field-effect transistor (FET) configured to electrically short at least one resistor of the plurality of resistors, and a control system. The control system may send a first command to the semiconductor switch to close, acquire a first voltage waveform, send a second command to the semiconductor switch to open, send a third command to the gain FET to close, send a fourth command to the semiconductor switch to close, acquire a second voltage waveform, and determine the isolation resistance based on the first voltage waveform and the second voltage waveform.
13 Citations
20 Claims
-
1. An energy storage system configured to output at least two voltage waveforms, comprising:
-
a semiconductor relay switch; one or more battery packs, wherein one terminal of the one or more battery packs of the energy storage system is electrically coupled to a resistor of a plurality of resistors, wherein the plurality of resistors is configured to electrically couple to the one or more battery packs via the semiconductor relay switch; a gain field-effect transistor (FET) configured to electrically short at least one resistor of the plurality of resistors, wherein the at least one resistor of the plurality of resistors is directly coupled to a voltage output terminal configured to output the at least two voltage waveforms for determining an isolation resistance of the energy storage system; and a control system configured to; send a first command to the semiconductor switch to close; acquire a first voltage waveform corresponding to a first voltage measurement over a first period of time at the voltage output terminal after the first command has been sent; send a second command to the semiconductor switch to open; send a third command to the gain FET to close after the second command has been sent, wherein the at least one resistor of the plurality of resistors is electrically shorted when the gain FET is closed; send a fourth command to the semiconductor switch to close after the third command has been sent; acquire a second voltage waveform corresponding to a second voltage measurement over a second period of time at the voltage output terminal after the fourth command has been sent; and determine the isolation resistance based at least in part on a Thevenin equivalent resistance calculated from the first voltage waveform and the second voltage waveform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A non-transitory computer-readable medium comprising computer-executable instructions configured to cause a processor to:
-
acquire a first voltage waveform corresponding to a first voltage measurement over a first period of time at a voltage output terminal configured to output at least two voltage waveforms when a plurality of resistors of a battery system is electrically coupled to one or more battery packs via a semiconductor relay switch; acquire a second voltage waveform corresponding to a second voltage measurement over a second period of time at the voltage output terminal in response to at least one resistor of the plurality of resistors directly coupled to the voltage output terminal being electrically shorted via a gain field-effect transistor (FET); determine an isolation resistance between a battery system and a chassis based at least in part on a Thevenin equivalent resistance calculated from the first voltage waveform and the second voltage waveform; and disconnect the one or more battery packs from the battery system in response to the isolation resistance being below a threshold resistance value. - View Dependent Claims (10, 11, 12, 13, 14, 15)
-
-
16. An isolation measurement circuit for measuring isolation resistance, comprising:
-
a semiconductor relay switch; a plurality of resistors configured to electrically couple to one or more battery packs via the semiconductor relay switch, wherein one terminal of the one or more battery packs is electrically coupled to a resistor of the plurality of resistors of a battery system; a gain field-effect transistor (FET) configured to electrically short at least one resistor of the plurality of resistors, wherein the at least one resistor of the plurality of resistors is directly coupled to a voltage output terminal configured to output a voltage waveform for determining an isolation resistance between the battery system and a chassis; one or more capacitors electrically coupled to a system ground of a vehicle and the one or more battery packs; and a control system configured to; acquire a first voltage waveform corresponding to a first voltage measurement over a first period of time at the voltage output terminal when the plurality of resistors is electrically coupled to the one or more battery packs via the semiconductor relay switch; acquire a second voltage waveform corresponding to a second voltage measurement over a second period of time at the voltage output terminal in response to the at least one resistor of the plurality of resistors directly coupled to the voltage output terminal being electrically shorted via the gain field-effect transistor (FET); and determine the isolation resistance between the battery system and the chassis based at least in part on a Thevenin equivalent resistance calculated from the first voltage waveform and the second voltage waveform. - View Dependent Claims (17, 18, 19, 20)
-
Specification