CN118150917A - High-voltage interlocking detection circuit, high-voltage electric system comprising same and vehicle - Google Patents
High-voltage interlocking detection circuit, high-voltage electric system comprising same and vehicle Download PDFInfo
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- CN118150917A CN118150917A CN202211561893.8A CN202211561893A CN118150917A CN 118150917 A CN118150917 A CN 118150917A CN 202211561893 A CN202211561893 A CN 202211561893A CN 118150917 A CN118150917 A CN 118150917A
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Abstract
The invention relates to a high-voltage interlocking detection circuit, which comprises: a power supply; a high voltage interlock module powered by the power source for monitoring a connection condition of a high voltage connector in a vehicle; a voltage dividing resistor connected in series with the high voltage interlock module; a first switch connected between the power source and the high voltage interlock module; a second switch having a first end connected to the power supply and a second end connected to a common node between the high voltage interlock module and the voltage dividing resistor; and a microcontroller configured to control on-off of the first switch and the second switch, and determine whether a connection failure occurs between a high-voltage connector in a vehicle and the high-voltage interlock detection circuit by calculating impedance of the high-voltage interlock module. The invention also relates to a high-voltage electrical system comprising the high-voltage interlock detection circuit, and a vehicle comprising the high-voltage electrical system.
Description
Technical Field
The present invention relates to the field of vehicle high voltage system protection, and more particularly, to a high voltage interlock detection circuit, a high voltage electric system including the same, and a vehicle including the same.
Background
In new energy vehicles (for example electric vehicles and hybrid vehicles), the power system thereof is provided by means of a power battery. The power system is a high-voltage electric system, all electric components are connected through a high-voltage connector, and as the working voltage of a power battery is high (generally 400V-600V), the high-voltage connector has a great potential safety hazard, and once the high-voltage connector fails, the operation safety of the whole power system of the vehicle can be influenced.
Accordingly, a high voltage interlock (High Voltage Interlock Loop, HVIL) is typically provided in the high voltage electrical system of the vehicle for monitoring the connection condition of the high voltage connector. However, the existing high-voltage interlocking device has low detection precision, and a self-checking function cannot be realized generally, so that once the high-voltage interlocking device itself fails, an incorrect detection result can occur.
Disclosure of Invention
In view of this, according to a first aspect of the present invention, there is provided a high-voltage interlock detection circuit including:
A power supply;
A high voltage interlock module powered by the power source and configured to monitor a connection condition of a high voltage connector in a vehicle;
the voltage dividing resistor is connected with the high-voltage interlocking module in series;
A first switch connected between the power source and the high voltage interlock module;
A second switch having a first end connected to the power source and a second end connected to a common node between the high voltage interlock module and the voltage dividing resistor; and
And the microcontroller is configured to control the on-off of the first switch and the second switch, and judge whether the connection fault occurs between a high-voltage connector in the vehicle and the high-voltage interlocking detection circuit by calculating the impedance of the high-voltage interlocking module.
According to an advantageous embodiment, the microcontroller comprises a first sampling port, a second sampling port and a third sampling port, the first sampling port being connected to a first end of the second switch, the second sampling port and the third sampling port being connected to both ends of the voltage dividing resistor, respectively, wherein the microcontroller is configured to calculate the impedance of the high voltage interlock module based on the sampling results of the first to third sampling ports.
According to an advantageous embodiment, the microcontroller is further configured to close the first switch and open the second switch, and to calculate a first impedance of the high voltage interlock module based on the sampling results of the first to third sampling terminals,
Wherein if the first impedance is less than a first threshold, indicating that no connection failure has occurred for the high voltage connector in the vehicle; if the first impedance is greater than or equal to a first threshold, a connection fault is indicated in a high voltage connector in the vehicle.
According to an advantageous embodiment, the microcontroller is further configured to:
Opening the first switch and closing the second switch, and calculating a second impedance of the high voltage interlock module based on sampling results of the first to third sampling terminals; and
Opening the first switch and the second switch, and calculating a third impedance of the high voltage interlock module based on sampling results of the first to third sampling terminals,
Wherein if the second impedance is zero and the third impedance is greater than or equal to a second threshold, indicating that no connection failure has occurred in the high voltage interlock detection circuit; if the second impedance is not zero or the third impedance is less than the second threshold, a connection failure in the high voltage interlock detection circuit is indicated.
According to an advantageous embodiment, the power source is a constant current source.
According to an advantageous embodiment, the first threshold value is set in accordance with the circuit design of the high-voltage connector.
According to an advantageous embodiment, the high voltage interlock detection circuit further comprises a ground connector arranged between the voltage dividing resistor and ground.
According to an advantageous embodiment, the microcontroller is further configured to disconnect the ground connector upon recognition of a connection failure in the high voltage interlock detection circuit and to send an alarm signal to a vehicle control unit upon recognition of a connection failure of the high voltage connector.
According to a second aspect of the present invention there is also provided a high voltage electrical system comprising a high voltage interlock detection circuit as described above.
According to a third aspect of the present invention there is also provided a vehicle comprising a high voltage electrical system as described above.
Advantageous advantages of the high voltage interlock detection circuit according to the present invention include:
-the cost of the newly added bill of materials (BOM) is relatively small;
the accuracy of the detection results is high, since an accurate estimation of the impedance of the high voltage interlock module can be achieved;
The self-checking function of the high-voltage interlocking detection circuit can be realized, and the false detection rate is further reduced; and
-A safety class ASIL C that can meet the high voltage interlock detection function of an electric vehicle in cooperation with software.
Further advantages are given by the dependent claims. The invention is not limited to the combination of features of the claims. Other reasonable combinations of the claims and/or individual claim features and/or the description features and/or the drawing features are available to the person skilled in the art, in particular from the objects proposed and/or by comparison with the prior art.
Drawings
Other features and advantages of the methods of the present invention will be apparent from, or are apparent from, the accompanying drawings, which are incorporated herein, and the detailed description of the invention, which, together with the drawings, serve to explain certain principles of the invention.
Fig. 1 is a schematic diagram showing the structure of a conventional high-voltage interlock detection circuit;
Fig. 2 shows a schematic configuration of a high voltage interlock detection circuit according to the present invention.
Detailed Description
The high voltage interlock detection circuit according to the present invention will be described below by way of example with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention to those skilled in the art. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. Rather, the invention can be considered to be implemented with any combination of the following features and elements, whether or not they relate to different embodiments. Thus, the various aspects, features, embodiments and advantages described below are for illustration only and should not be considered elements or limitations of the claims.
In a conventional high-voltage interlock detection circuit, electrical connection integrity of all high-voltage circuits (including system circuits such as an entire battery system, a wire, a connector, a DCDC, a motor controller, a high-voltage box, a protective cover, and the like) on an electric vehicle is usually checked by using a low-voltage signal of, for example, 5V or 12V, so as to check whether high-voltage components and high-voltage connectors on the whole vehicle are installed in place, and whether a short circuit or an open circuit occurs. When the high voltage interlock detection circuit detects a connector disconnection or a broken integrity in the high voltage circuit, the VCU (vehicle control unit) may be notified to initiate the necessary safety measures.
Fig. 1 shows a schematic configuration of a high voltage interlock detection circuit in the prior art. The circuit can utilize the low voltage signal to perform fault detection on the high voltage connector of the electric vehicle, so that the integrity of the whole high voltage electric system is confirmed.
As shown in fig. 1, the high-voltage interlock detection circuit includes a microcontroller MCU ' (or referred to as a "single chip microcomputer"), a power supply V1', and a voltage dividing circuit composed of a first resistor R1', a second resistor R2', and a high-voltage interlock module HVIL ', and determines whether a high-voltage connector in a vehicle is disconnected or shorted by collecting a voltage Vadc ' on the high-voltage interlock module HVIL '. However, the existing high-voltage interlocking detection circuit cannot realize self-detection, so that once the high-voltage interlocking detection circuit fails, an error detection result can be caused, and further potential safety hazards of the whole vehicle are caused. In addition, the existing high-voltage interlocking detection circuit has lower impedance detection precision on the high-voltage interlocking module, so that the false detection rate is further improved.
With the improvement of the safety requirements of users on vehicles, the safety requirements of automobile manufacturers on the high-voltage interlocking detection circuit are also higher and higher, and besides the improvement of the safety of the high-voltage interlocking detection circuit and the reliability of the detection result, the self-checking function of the high-voltage interlocking detection circuit is also expected to be realized.
Fig. 2 shows a schematic configuration of a high voltage interlock detection circuit according to the present invention. As shown in fig. 2, the circuit comprises a power supply V1, which may be, for example, a constant current source generator that may output a current according to the control of the microcontroller MCU to supply a low voltage, for example, 5V or 12V, to the high voltage interlock module HVIL. The high-voltage interlock module HVIL may be connected to a high-voltage connector in a high-voltage circuit of the vehicle to monitor the connection condition thereof.
In addition, the high voltage interlock detection circuit may further include a voltage dividing resistor R1 and a first switch S1 connected in series with the high voltage interlock module HVIL. The first switch S1 may be connected between the power supply V1 and the high voltage interlock module HVIL.
The high voltage interlock detection circuit may further include a second switch S2 having one end connected to the power source V1 and the other end connected to a common node between the high voltage interlock module HVIL and the voltage dividing resistor R1.
The high-voltage interlocking detection circuit can control the on-off of the first switch S1 and the second switch S2 by means of the microcontroller MCU, and judges whether the connection fault occurs between the high-voltage connector in the vehicle and the high-voltage interlocking detection circuit by calculating the impedance of the high-voltage interlocking module HVIL.
Specifically, as shown in fig. 2, the microcontroller MCU includes a first sampling port Vadc1, a second sampling port Vadc2, and a third sampling port Vadc3, wherein the first sampling port Vadc1 is connected to the power source V1 (i.e., connected to the one end of the second switch S2), and the second sampling port Vadc2 and the third sampling port Vadc3 are respectively connected to both ends of the voltage dividing resistor R1.
The microcontroller MCU may calculate the impedance Rx of the high voltage interlock module HVIL based on the sampling results of the first to third sampling terminals Vadc1, vadc2, vadc3, and further determine whether a connection failure occurs in the high voltage connector or the high voltage interlock detection circuit itself in the vehicle based on the calculated impedance Rx.
Specifically, when it is required to detect a connection failure in the high voltage connector, that is, when the high voltage interlock detection circuit is operating normally, the first switch S1 is closed and the second switch S2 is opened by means of the microcontroller MCU. In this switching state, the microcontroller controls the power supply V1 (which is, for example, a constant current source generator) to output a current, which flows from the constant current source generator V1, through the first switch S1 and the high voltage interlock module HVIL, and finally through the resistor R1 to the ground.
Since the resistance value of the resistor R1 is known, and the impedance Rx of the high voltage interlock module HVIL is unknown, by detecting the voltage difference across the resistor R1, that is, the difference between the second sampling terminal Vadc2 and the third sampling terminal Vadc3, the current I1 flowing through the resistor R1 (the current I1 is the output current of the constant current source generator V1), that is:
Since the high voltage interlock module HVIL is connected in series with R1, the current flowing through the high voltage interlock module HVIL and the current flowing through the resistor R1 are the same, and thus the current flowing through the high voltage interlock module HVIL is also I1. The impedance Rx flowing through the high voltage interlock module HVIL can be precisely measured by detecting the voltage difference between the first sampling terminal Vadc1 and the second sampling terminal Vadc2, that is:
That is, with the first switch S1 closed and the second switch S2 open, the microcontroller MCU may calculate the impedance Rx (referred to herein as "first impedance") of the high voltage interlock module HVIL based on the sampling results of the first to third sampling terminals. Based on the calculated impedance Rx, the microcontroller may further determine whether a connection failure has occurred in the high voltage connector in the vehicle.
In particular, if the calculated impedance Rx is relatively small, e.g. less than 120 ohms (the threshold may be set by the vehicle manufacturer according to the circuit design of different high voltage wire harness connectors), it is indicative that the relevant high voltage connectors in the vehicle are well connected. If the calculated impedance Rx is relatively large, e.g. greater than or equal to 120 ohms (which is determined by the electric vehicle manufacturer as a threshold value), indicating that the relevant high voltage connector is in poor contact, an alarm message needs to be sent to the vehicle VCU to cause it to take corresponding safety measures. Specific security measures that may be taken include, for example:
-performing a fault alarm, for example by means of a warning light of an instrument or by sounding a warning sound, etc. to alert the driver to the condition of the vehicle, and sending the vehicle to a professional maintenance spot for maintenance as soon as possible, in order to avoid the occurrence of a safety accident;
cutting off the high-voltage electric output of the vehicle (for example, cutting off the power battery of the vehicle) so that the vehicle cannot be started, thereby maximizing the safety of the passengers;
-reducing the high voltage output of the vehicle, in particular, when the vehicle is in a driving state, by means of the high voltage electrical system, forcing the output of the motor to be reduced, thereby reducing the vehicle speed to keep the vehicle in a low speed operating state, so as to reserve the driver sufficient time and opportunity to find a suitable place to park.
When the high-voltage interlocking detection circuit needs to be subjected to self-checking, the self-checking operation can be sequentially performed twice. First, in the first self-checking operation, the first switch S1 is opened and the second switch S2 is closed by means of the microcontroller MCU, and the second impedance of the high voltage interlock module HVIL is calculated based on the sampling results of the first to third sampling terminals Vadc1, vadc2, vadc3, and if the second impedance is zero, it indicates that the first self-checking operation result is acceptable.
Subsequently, in the second self-checking operation, both the first switch S1 and the second switch S2 are turned off by means of the microcontroller MCU, and a third impedance of the high voltage interlock module HVIL is calculated based on the sampling results of the first to third sampling terminals Vadc1, vadc2, vadc3, which indicates that the second self-checking operation result is acceptable if the third impedance is large, for example, greater than ten thousand ohms.
And if the secondary self-checking operation results are all qualified, namely the second impedance is zero and the third impedance is greater than or equal to the threshold value, the high-voltage interlocking detection circuit is indicated to work normally. If there is a failure of the result of the self-checking operation, for example, the second impedance is not zero or the third impedance is smaller than the threshold value, it indicates that the high-voltage interlock detection circuit itself fails, and then the necessary safety measures need to be activated.
According to an alternative example, as shown in fig. 2, the high-voltage interlock detection circuit further includes a ground connector K1 (which is, for example, a constant current source sink) provided between the voltage dividing resistor R1 and the ground line. When a connection failure in the high voltage interlock detection circuit is identified, the microcontroller MCU may disconnect the ground connector K1 to disconnect the output signal of the constant current source generator.
Advantageous advantages of the high voltage interlock detection circuit according to the present invention include:
-the cost of the newly added bill of materials (BOM) is relatively small;
the accuracy of the detection results is high, since an accurate estimation of the impedance of the high voltage interlock module can be achieved;
The self-checking function of the high-voltage interlocking detection circuit can be realized, and the false detection rate is further reduced; and
-A safety class ASIL C that can meet the high voltage interlock detection function of an electric vehicle in cooperation with software.
While the invention has been described in terms of preferred embodiments, the invention is not limited thereto. Any person skilled in the art shall not depart from the spirit and scope of the present invention and shall accordingly fall within the scope of the invention as defined by the appended claims.
Claims (10)
1. A high voltage interlock detection circuit, the high voltage interlock detection circuit comprising:
a power supply (V1);
A high voltage interlock module (HVIL) powered by the power source (V1) and configured to monitor a connection condition of a high voltage connector in a vehicle;
A voltage dividing resistor (R1) connected in series with the high voltage interlock module (HVIL);
A first switch (S1) connected between the power supply (V1) and the high voltage interlock module (HVIL);
-a second switch (S2), the first end of which is connected to the power supply (V1), the second end of which is connected to a common node between the high voltage interlock module (HVIL) and the voltage divider resistor (R1); and
A Microcontroller (MCU) configured to control on-off of the first switch (S1) and the second switch (S2), and determine whether a connection failure occurs in a high voltage connector in a vehicle and the high voltage interlock detection circuit by calculating an impedance of the high voltage interlock module (HVIL).
2. The high voltage interlock detection circuit according to claim 1, wherein the microcontroller comprises a first sampling port (Vadc 1), a second sampling port (Vadc 2) and a third sampling port (Vadc 3), the first sampling port (Vadc 1) being connected to a first end of the second switch (S2), the second sampling port (Vadc 2) and the third sampling port (Vadc 3) being connected to both ends of the voltage dividing resistor (R1), respectively, wherein the microcontroller is configured to calculate the impedance of the high voltage interlock module (HVIL) based on the sampling results of the first to third sampling ports.
3. The high voltage interlock detection circuit of claim 2 wherein the Microcontroller (MCU) is further configured to close the first switch (S1) and open the second switch (S2) and calculate a first impedance of the high voltage interlock module (HVIL) based on the sampling results of the first through third sampling terminals,
Wherein if the first impedance is less than a first threshold, indicating that no connection failure has occurred for the high voltage connector in the vehicle; if the first impedance is greater than or equal to a first threshold, a connection fault is indicated in a high voltage connector in the vehicle.
4. A high voltage interlock detection circuit as recited in any one of claims 1 to 3, wherein the Microcontroller (MCU) is further configured to:
Opening the first switch (S1) and closing the second switch (S2), and calculating a second impedance of the high voltage interlock module (HVIL) based on sampling results of the first to third sampling terminals; and
Opening the first switch (S1) and the second switch (S2), and calculating a third impedance of the high voltage interlock module (HVIL) based on the sampling results of the first to third sampling terminals,
Wherein if the second impedance is zero and the third impedance is greater than or equal to a second threshold, indicating that no connection failure has occurred in the high voltage interlock detection circuit; if the second impedance is not zero or the third impedance is less than the second threshold, a connection failure in the high voltage interlock detection circuit is indicated.
5. A high voltage interlock detection circuit according to any one of claims 1 to 3, characterized in that the power source (V1) is a constant current source.
6. A high voltage interlock detection circuit as recited in claim 3 wherein the first threshold is set in accordance with a circuit structural design of the high voltage connector.
7. A high-voltage interlock detection circuit according to any one of claims 1 to 3, further comprising a ground connector (K1) provided between the voltage dividing resistor (R1) and a ground line.
8. The high voltage interlock detection circuit of claim 7 wherein the Microcontroller (MCU) is further configured to disconnect the ground connector (K1) upon identification of a connection failure in the high voltage interlock detection circuit and to send an alarm signal to a vehicle control unit upon identification of a connection failure of the high voltage connector.
9. A high-voltage electrical system, characterized in that it comprises a high-voltage interlock detection circuit according to any one of claims 1 to 8.
10. A vehicle characterized in that it comprises a high-voltage electrical system according to claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211561893.8A CN118150917A (en) | 2022-12-07 | 2022-12-07 | High-voltage interlocking detection circuit, high-voltage electric system comprising same and vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211561893.8A CN118150917A (en) | 2022-12-07 | 2022-12-07 | High-voltage interlocking detection circuit, high-voltage electric system comprising same and vehicle |
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| CN118150917A true CN118150917A (en) | 2024-06-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211561893.8A Pending CN118150917A (en) | 2022-12-07 | 2022-12-07 | High-voltage interlocking detection circuit, high-voltage electric system comprising same and vehicle |
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| Country | Link |
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| CN (1) | CN118150917A (en) |
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- 2022-12-07 CN CN202211561893.8A patent/CN118150917A/en active Pending
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