ELECTRIC VEHICLE BATTERY CONTACTOR SWITCH MONITORING
First Claim
1. An electric vehicle system, comprising:
- a multi-cell battery pack providing a main battery voltage between a positive bus and a negative bus;
a first contactor switch selectably coupling the positive bus to a load;
a main microcontroller monitoring performance of the battery pack and contactor switches, the main microcontroller being coupled to a chassis ground and being digitally isolated from the positive and negative busses;
a battery monitoring IC connected to the battery pack to measure respective voltages of cells in the battery pack, wherein the battery monitoring IC has an isolated serial data link to the main microcontroller to report the measured voltages, and wherein the battery monitoring IC further includes a plurality of auxiliary/thermistor A/D inputs and an auxiliary output terminal selectably providing a drive signal;
an evaluation switch having an input, an output, and a control terminal, wherein the input is connected to a junction between the first contactor switch and the load, and wherein the control terminal is coupled to the auxiliary output terminal so that the evaluation switch is activated in response to a command received from the main microprocessor over the serial data link; and
a voltage divider coupled between the output of the evaluation switch and the negative bus and providing a divided voltage output to one of the auxiliary/thermistor A/D inputs;
wherein the battery monitoring IC transmits a digital value representative of the divided voltage output to the main microprocessor via the serial data link, and wherein the main microprocessor determines a state of the first contactor in response to the digital value.
1 Assignment
0 Petitions
Accused Products
Abstract
Contactor switches between a multi-cell battery pack and an electric vehicle load are monitored. A main microcontroller having a chassis ground is digitally isolated from positive and negative busses of the battery pack. A battery monitoring IC having a plurality of auxiliary/thermistor A/D inputs measures respective voltages of battery cells. An evaluation switch is connected to a junction between a first contactor switch and the load. The evaluation switch is activated in response to a command received from the main microprocessor. A voltage divider is coupled between the output of the evaluation switch and the negative bus to provide a divided voltage output to one of the auxiliary/thermistor A/D inputs. The battery monitoring IC transmits a digital value representative of the divided voltage output to the main microprocessor via a serial data link, and the main microprocessor determines a state of the contactor in response to the digital value.
-
Citations
11 Claims
-
1. An electric vehicle system, comprising:
-
a multi-cell battery pack providing a main battery voltage between a positive bus and a negative bus; a first contactor switch selectably coupling the positive bus to a load; a main microcontroller monitoring performance of the battery pack and contactor switches, the main microcontroller being coupled to a chassis ground and being digitally isolated from the positive and negative busses; a battery monitoring IC connected to the battery pack to measure respective voltages of cells in the battery pack, wherein the battery monitoring IC has an isolated serial data link to the main microcontroller to report the measured voltages, and wherein the battery monitoring IC further includes a plurality of auxiliary/thermistor A/D inputs and an auxiliary output terminal selectably providing a drive signal; an evaluation switch having an input, an output, and a control terminal, wherein the input is connected to a junction between the first contactor switch and the load, and wherein the control terminal is coupled to the auxiliary output terminal so that the evaluation switch is activated in response to a command received from the main microprocessor over the serial data link; and a voltage divider coupled between the output of the evaluation switch and the negative bus and providing a divided voltage output to one of the auxiliary/thermistor A/D inputs; wherein the battery monitoring IC transmits a digital value representative of the divided voltage output to the main microprocessor via the serial data link, and wherein the main microprocessor determines a state of the first contactor in response to the digital value. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method comprising:
-
digitally isolating a main microprocessor from a battery monitoring IC; selectably coupling a voltage divider between a load side of a positive contactor switch and a battery side of a negative bus; digitally sampling a divided voltage using an auxiliary/thermistor input of the IC; transmitting a digital sample to the main microprocessor via an isolated serial data link; evaluating the digital sample to determine an open/closed state of the switch. - View Dependent Claims (8)
-
-
9. An electric vehicle system, comprising:
-
a multi-cell battery pack providing a main battery voltage between a positive bus and a negative bus; a first contactor switch selectably coupling the positive bus to a load; a main microcontroller monitoring performance of the battery pack and contactor switches, the main microcontroller being coupled to a chassis ground and being digitally isolated from the positive and negative busses; a battery monitoring IC connected to the battery pack to measure respective voltages of cells in the battery pack, wherein the battery monitoring IC has an isolated serial data link to the main microcontroller to report the measured voltages, and wherein the battery monitoring IC further includes a plurality of auxiliary/thermistor A/D inputs and an auxiliary output terminal selectably providing a drive signal; an evaluation switch having an input, an output, and a control terminal, wherein the input is connected to a junction between the first contactor switch and the load, and wherein the control terminal is coupled to the auxiliary output terminal so that the evaluation switch is activated in response to a command received from the main microprocessor over the serial data link; and a voltage divider coupled between the output of the evaluation switch and the negative bus and providing a divided voltage output to one of the auxiliary/thermistor A/D inputs; wherein the battery monitoring IC transmits a digital value representative of a voltage at the junction between the first contactor switch and the load. - View Dependent Claims (10, 11)
-
Specification