System for controlling operation of a contactor using a high side sense circuit and a low side sense circuit

A system for controlling operation of a contactor is provided. The system stops outputting a control signal to open the contactor, and then measures a low side sense signal from a low side sense circuit electrically coupled to a low side end of a contactor coil, or a high side sense signal from a high side sense circuit that is electrically coupled to a high side end of the contactor coil, to determine whether the contactor has a closed operational position, and if not, the system stops outputting another control signal to open the contactor.

BACKGROUND

The inventors herein have recognized a need for an improved system for controlling operation of a contactor. The system provides a technical effect of utilizing diagnostic diversity for opening a contactor. In particular, the system stops outputting a control signal to open the contactor, and then measures a low side sense signal from a low side sense circuit electrically coupled to a low side end of a contactor coil, or a high side sense signal from a high side sense circuit that is electrically coupled to a high side end of the contactor coil, to determine whether the contactor has a closed operational position, and if not, the system stops outputting another control signal to open the contactor.

SUMMARY

A system for controlling operation of a contactor in accordance with an exemplary embodiment is provided. The contactor includes a contactor coil and a contact. The system includes a microcontroller having first and second analog-to-digital converters and first and second output ports. The first output port controls whether a low side end of the contactor coil is electrically coupled to electrical ground. The second output port controls whether a high side end of the contactor coil receives an energization voltage. The system further includes a low side sense line that is electrically coupled to and between the low side end of the contactor coil and a low side sense circuit. The low side sense circuit is further electrically coupled to the first analog-to-digital converter. The system further includes a high side sense line that is electrically coupled to and between the high side end of the contactor coil and a high side sense circuit. The high side sense circuit is further electrically coupled to the second analog-to-digital converter. The microcontroller is programmed to receive a command message to open the contact of the contactor, from an external controller. The microcontroller is further programmed to stop generating a first control signal on the first output port to de-energize the contactor coil to open the contact of the contactor, in response to the command message from the external controller. The low side sense circuit receives a first signal from the low side sense line and outputs a low side sense signal corresponding to the first signal. The first analog-to-digital converter receives the low side sense signal and outputs a low side sense value corresponding to the low side sense signal. The microcontroller is further programmed to stop generating a second control signal on the second output port to de-energize the contactor coil to open the contact of the contactor, if the low side sense value is greater than a first threshold voltage value.

A system for controlling operation of a contactor in accordance with another exemplary embodiment is provided. The contactor has a contactor coil and a contact. The system includes a microcontroller having first and second analog-to-digital converters and first and second output ports. The first output port controls whether a low side end of the contactor coil is electrically coupled to electrical ground. The second output port controls whether a high side end of the contactor coil receives an energization voltage. The system further includes a low side sense line that is electrically coupled to and between the low side end of the contactor coil and a low side sense circuit. The low side sense circuit is further electrically coupled to the first analog-to-digital converter. The system further includes a high side sense line that is electrically coupled to and between the high side end of the contactor coil and a high side sense circuit. The high side sense circuit is further electrically coupled to the second analog-to-digital converter. The microcontroller is programmed to receive a command message to open the contact of the contactor, from an external controller. The microcontroller is further programmed to stop generating a second control signal on the second output port to de-energize the contactor coil to open the contact of the contactor, in response to the command message from the external controller. The high side sense circuit receives a first signal from the high side sense line and outputs a high side sense signal corresponding to the first signal. The second analog-to-digital converter receives the high side sense signal and outputs a high side sense value corresponding to the high side sense signal. The microcontroller is further programmed to stop generating a first control signal on the first output port to de-energize the contactor coil to open the contact of the contactor, if the high side sense value is greater than a first threshold voltage value.

DETAILED DESCRIPTION

Referring toFIG. 1, a vehicle10includes a system12for controlling operation of a contactor60, an external controller14, and a communication bus16. An advantage of the system12is that the system12utilizes diagnostic diversity for opening the contactor60. In particular, the system12stops outputting a control signal to open the contactor60, and then measures a low side sense signal from a low side sense circuit23electrically coupled to a low side end of a contactor coil182, or a high side sense signal from a high side sense circuit40that is electrically coupled to a high side end of the contactor coil182, to determine whether the contactor60has a closed operational position, and if not, the system12stops outputting another control signal to open the contactor60.

For purposes of understanding, the term “first and second analog-to-digital converters” refers to first and second banks of analog-to-digital converter channels.

The system12includes a microcontroller20, a low side driver circuit22, a low side sense line24, a low side sense circuit23, electrical lines26,28,29, a high side driver circuit40, a high side sense line42, a high side sense circuit43, electrical lines44,46,51, a contactor60, a battery module62, an electrical load64, electrical lines66,68.

The microcontroller20includes a microprocessor116, a memory118, analog-to-digital converters120,122, and first and second output ports130,132. The microcontroller20is programmed to perform diagnostic steps (described in flowcharts herein) utilizing the microprocessor116which executes software instructions stored in the memory118. The microprocessor116operably communicates with the memory118, the analog-to-digital converters120,122, and the first and second output ports130,132. The first output port130controls whether a low side end of the contactor coil180is electrically coupled to electrical ground. The second output port132controls whether a high side end of the contactor coil180receives an energization voltage.

The low side driver circuit22has an input node150and an output node152. The input node150is electrically coupled to the first output port130of the microcontroller20utilizing the electrical line26. The output node152is electrically coupled to a low side end of the contactor coil180utilizing the electrical line28. When the low side driver circuit22receives a first control signal from the first output port130of the microcontroller20, the low side driver circuit22electrically couples the low side end of the contactor coil180to electrical ground. When the low side driver circuit22does not receive the first control signal from the first output port130of the microcontroller20, the low side driver circuit22electrically de-couples the low side end of the contactor coil180from electrical ground.

The low side sense line24is electrically coupled to and between the low side end of the contactor coil180and the input node154of the low side sense circuit23.

The low side sense circuit23is provided to receive a first signal from the low side sense line24and to output a low side sense signal corresponding to the first signal to the analog-to-digital converter120. The low side sense circuit23includes an input node154and an output node155. The input node154is electrically coupled to the low side sense line24. The output node155is electrically coupled to the analog-to-digital converter120utilizing the electrical line29. The first signal from the low side sense line24can either be an electrical current or a voltage. Further, the low side sense signal from the low side sense circuit23can either be an electrical current or a voltage.

The high side driver circuit40has an input node160and an output node162. The input node160is electrically coupled to the second output port132of the microcontroller20utilizing the electrical line44. The output node162is electrically coupled to a high side end of the contactor coil180utilizing the electrical line46. When the high side driver circuit40receives a second control signal from the second output port132of the microcontroller20, the high side driver circuit40supplies an energization voltage to the high side end of the contactor coil180. When the high side driver circuit40does not receive the second control signal from the second output port132of the microcontroller20, the high side driver circuit40does not supply the energization voltage to the high side end of the contactor coil180.

The high side sense line42is electrically coupled to and between the high side end of the contactor coil180and the input node164of the high side sense circuit43.

The high side sense circuit43is provided to receive a second signal from the high side sense line42and to output a high side sense signal corresponding to the second signal to the analog-to-digital converter122. The high side sense circuit43includes an input node164and an output node165. The input node164is electrically coupled to the high side sense line42. The output node165is electrically coupled to the analog-to-digital converter122utilizing the electrical line51. The second signal from the high side sense line42can either be an electrical current or a voltage. Further, the high side sense signal from the high side sense circuit43can either be an electrical current or a voltage.

The contactor60is electrically coupled in series between a positive terminal200of the battery module62and the electrical load64. The contactor60includes the contactor coil180, a contact182, and a housing184. The housing184holds the contactor coil180and the contact182therein. When the microcontroller20generates first and second control signals on the output ports130,132, respectively that are received by the low side driver circuit22and the high side driver circuit40, respectively, the driver circuits22,40energize the contactor coil180, which moves the contact182to a closed operational position if the contactor60is operating as desired. Alternately, when the microcontroller20stops generating the first and second control signals, the driver circuits22,40de-energize the contactor coil180, which moves the contact182to an open operational position if the contactor60is operating as desired.

The battery module62includes a positive terminal200and a negative terminal202. The battery module62generates a voltage between the positive terminal200and the negative terminal202. The positive terminal200is electrically coupled to a first end of the contact182utilizing an electrical line66.

The electrical load64is electrically coupled to a second end of the contact182utilizing an electrical line68.

The external controller14operably communicates with the microcontroller20utilizing a communication bus16. The external controller14can send a command message to the microcontroller20requesting that the contactor60be transitioned to an open operational position such that an operational voltage from the battery module62is removed from the electrical load64to de-energize the electrical load64.

Referring toFIGS. 1 and 2, a flowchart of a first method300for controlling operation of the contactor60in accordance with another exemplary embodiment is provided.

At step302, the microcontroller20generates first and second control signals at the first and second output ports130,132, respectively, to induce the low side driver circuit22and the high side driver circuit40, respectively, to energize the contactor coil180to close the contact182of the contactor60. After step302, the method advances to step304.

At step304, the microcontroller20receives a command to open the contact182of the contactor60, from the external controller14. After step304, the method advances to step306.

At step306, the microcontroller20stops generating the first control signal on the first output port to induce the low side driver circuit22to de-energize the contactor coil180to open the contact182of the contactor60. After step306, the method advances to step308.

At step308, the low side sense circuit23receives a first signal from a low side sense line24and outputs a low side sense signal corresponding to the first signal. In an exemplary embodiment, the low side sense signal has an amplitude or a frequency that is proportional to an amplitude or a frequency of the first signal. After step308, the method advances to step310.

At step310, the first analog-to-digital converter120receives the low side sense signal and outputs a low side sense value corresponding to the low side sense signal. In an exemplary embodiment, the low side sense value has a magnitude that is proportional to an amplitude or a frequency of the low side sense signal. After step310, the method advances to step312.

At step312, the microcontroller20makes a determination as to whether the low side sense value is greater than a first threshold voltage value, indicating that the contact is welded in a closed operational position. If the value of step312equals “yes”, the method advances to step314. Otherwise, the method is exited.

At step314, the microcontroller20stops generating a second control signal on the second output port132to induce the high side driver circuit40to de-energize the contactor coil180to open the contact182of the contactor60. After step314, the method is exited.

Referring toFIGS. 1 and 3, a flowchart of a second method400for controlling operation of the contactor60in accordance with another exemplary embodiment is provided.

At step402, the microcontroller20generates first and second control signals at the first and second output ports130,132, respectively, to induce the low side driver circuit22and the high side driver circuit40, respectively, to energize the contactor coil180to close the contact182of the contactor60. After step402, the method advances to step404.

At step404, the microcontroller20receives a command to open the contact182of the contactor60, from the external controller14. After step404, the method advances to step406.

At step406, the microcontroller20stops generating the second control signal on the second output port132to induce the high side driver circuit40to de-energize the contactor coil180to open the contact182of the contactor60. After step406, the method advances to step408.

At step408, the high side sense circuit43receives a second signal from a high side sense line42and outputs a high side sense signal corresponding to the second signal. In an exemplary embodiment, the high side sense signal has an amplitude or a frequency that is proportional to an amplitude or a frequency of the second signal. After step408, the method advances to step410.

At step410, the second analog-to-digital converter122receives the high side sense signal and outputs a high side sense value corresponding to the high side sense signal. In an exemplary embodiment, the high side sense value has a magnitude that is proportional to an amplitude or a frequency of the high side sense signal. After step410, the method advances to step412.

At step412, the microcontroller20makes a determination as to whether the high side sense value is greater than a second threshold voltage value, indicating that the contact is welded in a closed operational position. If the value of step412equals “yes”, the method advances to step414. Otherwise, the method is exited.

At step414, the microcontroller20stops generating a first control signal on the first output port130to induce the low side driver circuit22to de-energize the contactor coil180to open the contact182of the contactor60. After step414, the method is exited.

The system for controlling a contactor described herein provides a substantial advantage over other systems and methods. In particular, the system provides a technical effect of utilizing diagnostic diversity for opening a contactor. The system stops outputting a control signal to open the contactor, and then measures a low side sense signal from a low side sense circuit electrically coupled to a low side end of a contactor coil, or a high side sense signal from a high side sense circuit that is electrically coupled to a high side end of the contactor coil, to determine whether the contactor has a closed operational position, and if not, the system stops outputting another control signal to open the contactor.