High-voltage interlock system and detection method thereof

• US 10,870,353 B2
• Filed: 03/19/2019
• Issued: 12/22/2020
• Est. Priority Date: 09/21/2018
• Status: Active Grant

• Current Assignee: Contemporary Amperex Runzhi Software Technology Limited
• Original Assignee: Contemporary Amperex Technology Co., Ltd.
• Inventors: Zeng, Yuqun, Wu, Kai, Dai, Wei, Wang, Chao, Li, Qiandeng
• Primary Examiner(s): Tran, Thienvu V
• Assistant Examiner(s): Quddus, Nusrat
• Application Number:
  US16/357,558
• Publication Number:
  US 20200094682A1
• Time in Patent Office: 644 Days
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/0084 relating to control modules
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• 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 50/50 using propulsion power supplied by batteries or fuel cells
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present disclosure provides a high-voltage interlock system and a detection method thereof. The high-voltage interlock system includes a target control device and at least one non-target control device connected in sequence. The target control device includes a detection unit, a current generation controller, a current generator, and a second high-voltage component. A controller in the target control device generates a pulse drive signal for driving the current generation controller, receives a detection result signal output from a current detector, and determines a fault of a high-voltage interlock circuit according to the detection result signal; the current generation controller generates an alternating voltage signal according to the pulse drive signal; the current generator outputs an alternating current signal according to the alternating voltage signal; the current detector acquires a voltage signal across a detection resistor set and outputs the detection result signal.

Claims

1. A high-voltage interlock system comprising:

a target control device and at least one non-target control device connected in sequence, wherein

the non-target control device comprises a detection unit and a first high-voltage component;

the detection unit comprises a controller, a current detector, and a detection resistor set;

the controller is connected to the current detector, and configured to receive a detection result signal output by the current detector and determine a fault of a high-voltage interlock circuit according to the detection result signal;

the current detector is connected to the detection resistor set, and configured to acquire a voltage signal across the detection resistor set and output the detection result signal according to the voltage signal;

the first high-voltage component is connected to the detection unit;

the target control device comprises the detection unit, a current generation controller, a current generator, and a second high-voltage component;

a controller in the target control device is connected to the current generation controller, and configured to generate a pulse drive signal for driving the current generation controller;

the current generation controller is connected to the current generator, and configured to generate an alternating voltage signal according to the pulse drive signal;

the current generator is connected to a detection resistor set in the target control device, and configured to output an alternating current signal according to the alternating voltage signal;

the second high-voltage component is connected to the current generator and the detection resistor set in the target control device; and

the current generator, the second high-voltage component, the detection resistor set in the target control device together with the detection resistor set and the first high-voltage component in the at least one non-target control device form the high-voltage interlock circuit in which the alternating current signal is transmitted;

wherein the current generation controller comprises a logic control circuit, a drive circuit, a current direction control circuit, and a first power source;

the logic control circuit is connected to the drive circuit and the controller in the target control device, and configured to generate a control signal for controlling the drive circuit based on the pulse drive signal;

the drive circuit is connected to the current direction control circuit and configured to control, based on the control signal, the current direction control circuit to control a direction of the alternating voltage signal;

the first power source has a positive pole connected to the current direction control circuit and is configured to supply power to the current direction control circuit; and

the current direction control circuit is connected to a negative pole of the first power source, and configured to control the alternating voltage signal to periodically change its direction in the current direction control circuit under the control of the drive circuit.

2. The high-voltage interlock system of claim 1, wherein:

the current direction control circuit comprises a first switch, a second switch, a third switch, a fourth switch, a first external terminal, and a second external terminal;

an end of the first switch and an end of the second switch are both connected to the first power source, the other end of the first switch is connected to an end of the third switch, the other end of the second switch is connected to an end of the fourth switch, and the other end of the third switch and the other end of the fourth switch are both connected to ground; and

the first external terminal is connected to the other end of the first switch and the end of the third switch, and the second external terminal is connected to the other end of the second switch and the end of the fourth switch.

3. The high-voltage interlock system of claim 1, wherein the current generator comprises a first constant current source, a second constant current source, a third constant current source, a fourth constant current source, a first current regulating resistor set, a second current regulating resistor set, a third current regulating resistor set, a fourth current regulating resistor set, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a seventh diode, an eighth diode, a first voltage dividing resistor set, and a second voltage dividing resistor set;

a first input terminal of the first constant current source is connected to the current generation controller, a cathode of the first diode, and a cathode of the second diode, a second input terminal of the first constant current source is connected to an end of the first current regulating resistor set and an anode of the third diode, an output end of the first constant current source is connected to an anode of the first diode, the other end of the first current regulating resistor set, and an end of the first voltage dividing resistor set, and the other end of the first voltage dividing resistor set is connected to ground;

a first input terminal of the second constant current source is connected to a cathode of the third diode, a cathode of the fourth diode, and an end of the detection resistor set in the target control device, a second input terminal of the second constant current source is connected to an anode of the second diode and an end of the second current regulating resistor set, and an output end of the second constant current source is connected to an anode of the fourth diode and the other end of the second current regulating resistor set;

a first input terminal of the third constant current source is connected to the current generation controller, a cathode of the fifth diode, and a cathode of the sixth diode, a second input terminal of the third constant current source is connected to an end of the third current regulating resistor set and an anode of the seventh diode, an output end of the third constant current source is connected to an anode of the fifth diode, the other end of the third current regulating resistor set, and an end of the second voltage dividing resistor set, and the other end of the second voltage dividing resistor set is connected to the ground; and

a first input terminal of the fourth constant current source is connected to a cathode of the seventh diode, a cathode of the eighth diode, and an end of the detection resistor set in the non-target control device, a second input terminal of the fourth constant current source is connected to an anode of the sixth diode and an end of the fourth current regulating resistor set, and an output end of the fourth constant current source is connected to an anode of the eighth diode and the other end of the fourth current regulating resistor set.

4. The high-voltage interlock system of claim 3, further comprising a first source detection unit and a second source detection unit, wherein:

the first source detection unit is connected to a detection terminal of the first voltage dividing resistor set, and configured to detect the first constant current source and the current generator; and

the second source detection unit is connected to a detection terminal of the second voltage dividing resistor set, and configured to detect the third constant current source and the current generator.

5. The high-voltage interlock system of claim 3, further comprising a first capacitor set and a second capacitor set, wherein:

an end of the first capacitor set is connected to the first input terminal of the second constant current source, and the other end of the first capacitor set is connected to the ground; and

an end of the second capacitor set is connected to the first input terminal of the fourth constant current source and the second high-voltage component, and the other end of the second capacitor set is connected to the ground.

6. The high-voltage interlock system of claim 1, wherein the current detector comprises a differential operational amplification unit and a limit value comparison unit;

the differential operational amplification unit has input terminals connected to both ends of the detection resistor set, and an output end connected to the limit value comparison unit, and is configured to amplify a voltage signal to a to-be-detected voltage signal to be input to the limit value comparison unit; and

the limit value comparison unit is connected to the controller, and configured to generate an upper limit signal threshold and a lower limit signal threshold, compare the to-be-detected voltage signal with the upper limit signal threshold and the lower limit signal threshold, and output a detection result signal.

7. The high-voltage interlock system of claim 1, wherein the target control device and at least one non-target control device are any of vehicle control systems.

8. A detection method for a high-voltage interlock system, wherein the detection method is applied to the high-voltage interlock system of claim 1 and comprises:

the controller in the target control device generating the pulse drive signal;

the current generation controller in the target control device generating the alternating voltage signal based on the pulse drive signal;

the current generator in the target control device outputting the alternating current signal to the high-voltage interlock circuit according to the alternating voltage signal;

the current detector in the target control device acquiring the voltage signal across the detection resistor set, and outputting the detection result signal according to the voltage signal; and

the controller in the target control device receiving the detection result signal output by the current detector, and determining the fault of the high-voltage interlock circuit based on the detection result signal.

9. The detection method for the high-voltage interlock system of claim 8, further comprising:

the current detector in the non-target control device acquiring the voltage signal across the detection resistor set, and outputting the detection result signal according to the voltage signal; and

the controller in the non-target control device receiving the detection result signal output by the current detector, and determining the fault of the high-voltage interlock circuit based on the detection result signal.

10. The detection method for the high-voltage interlock system of claim 8, wherein the current generation controller comprises a logic control circuit, a drive circuit, and a current direction control circuit, the logic control circuit is connected to the drive circuit and the controller in the target control device, the drive circuit is connected to the current direction control circuit, and the current direction control circuit is connected to the ground;

the current generation controller in the target control device generating the alternating voltage signal based on the pulse drive signal comprises;

the logic control circuit in the target control device generating a control signal for controlling the drive circuit according to the pulse drive signal;

the drive circuit in the target control device controlling the current direction control circuit to control the direction of the alternating voltage signal, according to the control signal; and

the current direction control circuit in the target control device controlling the alternating voltage signal to periodically change its direction in the current direction control circuit under the control of the drive circuit.

11. The detection method for the high-voltage interlock system of claim 10, wherein the current direction control circuit comprises a first switch, a second switch, a third switch, a fourth switch, a first external terminal, and a second external terminal;

an end of the first switch and an end of the second switch are both connected to the first power source, the other end of the first switch is connected to an end of the third switch, the other end of the second switch is connected to an end of the fourth switch, and the other end of the third switch and the other end of the fourth switch are both connected to ground;

the first external terminal is connected to the other end of the first switch and the end of the third switch, and the second external terminal is connected to the other end of the second switch and the end of the fourth switch;

the current direction control circuit in the target control device controlling the alternating voltage signal to periodically change its direction in the current direction control circuit under the control of the drive circuit comprises;

the current direction control circuit in the target control device periodically and alternately receiving a first direction control signal and a second direction control signal of the drive circuit, wherein;

the first direction control signal indicates that the first switch and the fourth switch are turned on, and the second switch and the third switch are turned off; and

the second direction control signal indicates that the second switch and the third switch are turned on, and the first switch and the fourth switch are turned off.

12. The detection method for the high-voltage interlock system of claim 8, wherein the current detector comprises a differential operational amplification unit and a limit value comparison unit, the differential operational amplification unit has input terminals connected to both ends of the detection resistor set and an output end connected to the limit value comparison unit, and the limit value comparison unit is connected to the controller in the target control device;

the current detector acquiring the voltage signal across the detection resistor set and outputting the detection result signal according to the voltage signal comprises;

the differential operational amplification unit amplifying the voltage signal into a to-be-detected voltage signal to be input into the limit value comparison unit;

the limit value comparison unit generating an upper limit signal threshold and a lower limit signal threshold, comparing the to-be-detected voltage signal with the upper limit signal threshold and the lower limit signal threshold, and outputting a detection result signal.

13. The detection method for the high-voltage interlock system of claim 8, wherein the high-voltage interlock system further comprises a first source detection unit and a second source detection unit, the current generator comprises a first constant current source and a third constant current source;

before the current generation controller in the target control device generates the alternating voltage signal according to the pulse drive signal, the detection method for the high-voltage interlock system further comprises;

the first source detection unit and the second source detection unit respectively detecting whether an output voltage of the first constant current source and an output voltage of the third constant current source are greater than a first voltage threshold;

the first source detection unit determining that the first constant current source is shorted if the output voltage of the first constant current source is greater than the first voltage threshold; and

the second source detection unit determining that the third constant current source is shorted if the output voltage of the third constant current source is greater than the first voltage threshold.

14. The detection method for the high-voltage interlock system of claim 8, wherein the high-voltage interlock system further comprises a first source detection unit, the current generation controller comprises a first power source, the current generator includes a first constant current source, and a first input terminal of the first constant current source is connected to the current generation controller;

the detection method for the high-voltage interlock system further comprises;

the controller in the target control device generating a drive signal with a duty ratio of 0 for driving the current generation controller;

the first source detection unit detecting whether an output voltage of the first constant current source is less than a second voltage threshold;

the first source detection unit determining that the first constant current source is open if the output voltage of the first constant current source is less than the second voltage threshold;

the first source detection unit detecting whether a difference between a voltage of the first power source and the output voltage of the first constant current source is less than a third voltage threshold; and

the first source detection unit determining that the current generator is shorted if the difference between the voltage of the first power source and the output voltage of the first constant current source is less than the third voltage threshold.

15. The detection method for the high-voltage interlock system of claim 9, wherein the high-voltage interlock system further comprises a second source detection unit, the current generation controller comprises a first power source, the current generator includes a third constant current source, and an output end of the third constant current source is connected to the current generation controller;

the detection method for the high-voltage interlock system further comprises;

the controller in the target control device generating a drive signal with a duty ratio of 100% for driving the current generation controller;

the second source detection unit detecting whether an output voltage of the third constant current source is less than a fourth voltage threshold;

the second source detection unit determining that the third constant current source is open if the output voltage of the third constant current source is less than the fourth voltage threshold;

the second source detection unit detecting whether a difference between a voltage of the first power source and the output voltage of the third constant current source is less than a fifth voltage threshold; and

the second source detection unit determining that the current generator is shorted if the difference between the voltage of the first power source and the output voltage of the third constant current source is less than the fifth voltage threshold.

16. The detection method for the high-voltage interlock system of claim 9, wherein the current detector comprises a differential operational amplification unit and a limit value comparison unit, the differential operational amplification unit has input terminals connected to both ends of the detection resistor set and an output end connected to the limit value comparison unit, and the limit value comparison unit is connected to the controller in the target control device;

the current detector acquiring the voltage signal across the detection resistor set and outputting the detection result signal according to the voltage signal comprises;

the differential operational amplification unit amplifying the voltage signal into a to-be-detected voltage signal to be input into the limit value comparison unit;

the limit value comparison unit generating an upper limit signal threshold and a lower limit signal threshold, comparing the to-be-detected voltage signal with the upper limit signal threshold and the lower limit signal threshold, and outputting a detection result signal.