A method and system for detecting a fault in a control terminal of an explosion fuse

Abstract

The present application relates to the technical field of battery management module, and more particularly to a kind of explosion fuse control end fault detection method and system.A kind of explosion fuse control end fault detection method, including first type fault detection: first detection loop is turned on, negative control end module, negative control end dry road resistance R3 and voltage division sampling unit are connected in series, explosion fuse control end equivalent resistance and parallel resistance R2 are connected in parallel with the voltage division sampling unit respectively;The voltage value V1 of detection sampling point A is calculated, the first voltage diagnostic value interval of the sampling point A under different first type fault condition is calculated, whether the voltage value V1 is in the first voltage diagnostic value interval is judged, and whether the corresponding first fault type fault of the explosion fuse control end exists is diagnosed.The type fault of positive control end and negative control end of explosion fuse can be effectively identified by using the above technical scheme, and the explosion fuse control circuit fault occurrence position is accurately positioned.

Description

Technical Field

[0001] This invention relates to the field of battery management module technology, and in particular to a method and system for detecting faults in the control terminal of an exploding fuse. Background Technology

[0002] With the advancement of the new energy strategy, the development of new energy vehicles is rapid, and longer driving range is the trend. However, a longer driving range inevitably requires more battery capacity, which significantly increases charging time. One of the main methods to solve the problem of excessively long charging time is to increase the voltage level of the entire vehicle system. Higher voltage leads to increased insulation requirements and improved short-circuit protection measures for the entire system. Fuses are crucial components for short-circuit protection in high-voltage systems. When an external short circuit or collision occurs in the high-voltage electrical circuit, it is extremely important that the fuse can promptly disconnect the electrical connection, ensuring the entire energy circuit remains open.

[0003] A conventional fuse is a passive protection device that breaks the circuit by melting its fusible element due to the heat generated when the current exceeds a specified value for a certain period. A pyro-fuse, on the other hand, is an active protection device that breaks the electrical connection by applying voltage to the control side, generating a current exceeding a specified value for a certain period, triggering an explosive impact that drives an actuator to cut off the connecting conductors. In the event of a vehicle collision or a short circuit in the high-voltage circuit, the pyro-fuse must disconnect the battery power immediately upon detecting the accident. After the battery and controller power points are disconnected, even if the auxiliary circuits short-circuit or the protection circuit fails, the short circuit will not cause a fire or damage to electrical components, further improving the overall vehicle safety.

[0004] Currently, the conventional control strategy for exploding fuses is relatively simple. The main control method involves the Battery Management System (BMS) directly applying voltage to the control terminal of the exploding fuse when it detects a vehicle collision or a short circuit in the high-voltage system, thereby triggering an explosion. However, the reliability of this control circuit is not well guaranteed. Therefore, providing a detection method and system capable of accurately locating the fault location and type at the control terminal of an exploding fuse has become a technical problem that needs to be solved. Summary of the Invention

[0005] To overcome the above-mentioned technical defects, the purpose of this invention is to provide a method and system for detecting faults in the control terminal of an exploding fuse. The method detects the voltages V1 and V2 at sampling point A, and then identifies the type of fault in the positive and negative control terminals of the exploding fuse by using the voltage values ​​of V1 and V2, thereby accurately locating the fault location in the control circuit of the exploding fuse.

[0006] The present invention provides a method for detecting faults in the control terminal of an explosion fuse, including the first type of fault detection: conducting the first detection circuit, the negative control terminal module, the negative control terminal main circuit resistor R3 and the voltage division sampling unit are connected in series, and the equivalent resistor Rp of the explosion fuse control terminal and the parallel resistor R2 are respectively connected in parallel with the voltage division sampling unit; detecting the voltage value V1 at the sampling point A of the voltage division sampling unit, calculating the first voltage diagnosis value range of the sampling point A in different first type of fault situations, determining whether the voltage value V1 is within the first voltage diagnosis value range, and diagnosing whether there is a first type of fault corresponding to the first voltage diagnosis value range at the explosion fuse control terminal.

[0007] Further, it also includes the second type of fault detection: conducting the second detection circuit, the positive control terminal module, the positive control terminal main circuit resistor R1, the voltage division sampling unit and the parallel resistor R2 are connected in series, and the equivalent resistor Rp of the explosion fuse control terminal is connected in parallel with the parallel resistor R2; detecting the voltage value V2 at the sampling point A of the voltage division sampling unit, calculating the second voltage diagnosis value range of the sampling point A in different second type of fault situations, determining whether the voltage value V2 is within the second voltage diagnosis value range, and diagnosing whether there is a second type of fault corresponding to the second voltage diagnosis value range at the explosion fuse control terminal; when the voltage value V1 is not within the first voltage diagnosis value range and the voltage value V2 is not within the second voltage diagnosis value range, diagnosing that there is an other fault at the explosion fuse control terminal, and the other fault is a fault of the explosion fuse control terminal other than the first type of fault and the second type of fault.

[0008] Further, the first type of fault detection includes: calculating the diagnostic voltage values V0 and Va, V0 = 0V, Va = U2_max * (Rp / (Rp + R3)) * (R5 / (R4 + R5)), where U2_max is the maximum voltage value of the negative control terminal power supply U2, Rp is the equivalent resistor value of the explosion fuse control terminal when no fault occurs, R4 and R5 are the resistance values of the voltage division resistors R4 and R5 connected in series in the voltage division sampling unit, one end of the voltage division resistor R5 is grounded, and the other end is set as the sampling point A; when V1 < V0 + a, diagnosing that there is a short circuit to the negative power supply at the negative control terminal of the explosion fuse; when V1 < Va, diagnosing that there is a short circuit to the negative power supply at the positive control terminal of the explosion fuse; where a is the redundancy set by the system.

[0009] Further, the first type of fault detection further includes: calculating a diagnostic voltage value Vb, where Vb = U2_max * (Rb / (Rb + R3)) * (R5 / (R4 + R5)), and Rb is the parallel equivalent resistance value of R4 + R5 and R2; when V1 < Vb, it is diagnosed that there is a short to the negative power supply at the positive control terminal of the explosive fuse and there is an open circuit fault between the positive control terminal and the negative control terminal.

[0010] Further, the first type of fault detection further includes: calculating voltage diagnostic values Vc and Vd, where Vc = U2_min * (R5 / (R3 + R4 + R5)) - a, Vd = U2_max * (R5 / (R3 + R4 + R5)) + a; U2_min is the minimum voltage value of the power supply at the negative control terminal; when Vc ≤ V1 ≤ Vd, it is diagnosed that there is no short to the positive power supply fault and / or short to the negative power supply fault between the positive control terminal and the negative control terminal of the explosive fuse.

[0011] Further, the first type of fault detection further includes: calculating voltage diagnostic values VPsb_max and VPsb_min, where VPsb_min = (R5 / (R4 + R5)) * (U2_min / R3 + U1_min / R2) / (1 / (R4 + R5) + 1 / R2 + 1 / R3); VPsb_max = (R5 / (R4 + R5)) * (U2_max / R3 + U1_max / Rb1) / (1 / (R4 + R5) + 1 / Rb1 + 1 / R3); Rb1 is the parallel equivalent resistance value of R2 and a 10KΩ resistor; when VPsb_min < V1 < VPsb_max, it is diagnosed that there is a short to the positive power supply at the positive control terminal of the explosive fuse and there is an open circuit fault between the positive control terminal and the negative control terminal.

[0012] Further, the first type of fault detection further includes: calculating voltage diagnostic values Ve and Vf, where Ve = U1_min * (R5 / (Rp + R4 + R5)), Vf = U1_max * (R5 / (R4 + R5)); U1_min is the minimum voltage value of the power supply at the positive control terminal, and U1_max is the maximum voltage value of the power supply at the positive control terminal; when Ve ≤ V1 ≤ Vf, it is diagnosed that there is a short to the positive power supply at the positive control terminal and / or the negative control terminal of the explosive fuse.

[0013] Further, the second type of fault detection includes: calculating voltage diagnostic values Vg and Vh, where Vg = U1_min * R5 / (R1 + Rp + R4 + R5) - a, Vh = U1_max * R5 / (R1 + Rp + R4 + R5) + a; when Vg ≤ V2 ≤ Vh, it is diagnosed that there is no open circuit fault between the positive control terminal and the negative control terminal of the explosive fuse and there is no short to the negative power supply fault between the positive control terminal and the negative control terminal.

[0014] Furthermore, the first conduction detection circuit includes a first control unit turning off MOSFETs T1 and T2, and a second control unit turning off MOSFET T3; the second conduction detection circuit includes a first control unit turning on MOSFETs T1 and T2, and a second control unit turning off MOSFET T3.

[0015] Furthermore, the first detection circuit is first activated to perform the first fault type fault detection, and after the first detection circuit is activated, the second fault type fault detection is performed; or, the second detection circuit is first activated to perform the second fault type fault detection, and after the second detection circuit is activated, the first detection circuit is activated to perform the first fault type fault detection; if a fault is diagnosed at the control terminal of the explosion fuse, the fault is eliminated and the detection continues until all faults are detected.

[0016] This invention also provides a fault detection system for the control terminal of an exploding fuse, including a positive control terminal module, a negative control terminal module, and a sampling and diagnostic module. The sampling and diagnostic module includes a positive control terminal main circuit resistor R1, a negative control terminal main circuit resistor R3, a parallel resistor R2, a voltage divider sampling unit, and a diagnostic unit. One end of the voltage divider sampling unit is connected to the positive control terminal module through the positive control terminal main circuit resistor R1, and the other end is connected to the negative control terminal module through the negative control terminal main circuit resistor R3. A parallel resistor R2 is connected between R1 and R3, and the parallel resistor R2 is connected in parallel between the positive and negative control terminals of the exploding fuse. The system includes a first detection circuit, which consists of the negative control terminal module, the negative control terminal main circuit resistor R3, and the voltage divider sampling unit connected in series. The equivalent resistance Rp and parallel resistance R2 of the fuse control terminal are connected in parallel with the voltage divider sampling unit. The positive control module and the negative control terminal module are used to power the system and control the conduction and shutdown of the first detection circuit. One end of the voltage divider sampling unit is grounded, and the other end is connected to the negative control terminal main circuit resistor R3. The voltage divider sampling unit is set with sampling point A, which is connected to the input terminal of the diagnostic unit. The diagnostic unit is used to detect the voltage value V1 of the sampling point A, calculate the first voltage diagnostic value range of the sampling point A under different first type of fault conditions, determine whether the voltage value V1 is within the first voltage diagnostic value range, and diagnose whether the fuse control terminal has a first type of fault corresponding to the first voltage diagnostic value range.

[0017] Furthermore, it also includes a second detection circuit, which is composed of the positive control terminal module, the positive control terminal main circuit resistor R1 and the voltage divider sampling unit, and the parallel resistor R2 connected in series, and the equivalent resistance Rp of the fuse control terminal connected in parallel with the parallel resistor R2. The positive control module and the negative control terminal module are also used to control the conduction and shutdown of the second detection circuit. The diagnostic unit is also used to detect the voltage value V2 of the sampling point A, calculate the second voltage diagnostic value range of the sampling point A under different first type of fault conditions, determine whether the voltage value V1 is within the first voltage diagnostic value range, and diagnose whether the fuse control terminal has a second type of fault corresponding to the second voltage diagnostic value range.

[0018] Further, the positive control module includes a positive control power supply U1, a first control unit, and MOSFETs T1 and T2. The first control unit controls the on and off states of MOSFETs T1 and T2. The output of MOSFET T1 is connected to MOSFET T2 and is used to control the on and off states of MOSFET T1. The negative control module includes a negative control power supply U2, a second control unit, and MOSFET T3. The second control unit controls the on and off states of MOSFET T3. MOSFETs T1, T2, and T3 are configured to: conduct a first detection circuit when MOSFETs T1, T2, and T3 are off; and conduct a second detection circuit when MOSFETs T1 and T2 are on and MOSFET T3 is off.

[0019] Further, the gate of MOSFET T1 is connected to the output of the first control unit, the second terminal of MOSFET T1 is grounded, and the third terminal of MOSFET T1 is connected in series with the current-limiting resistor R12 and the gate of MOSFET T2; the first terminal of MOSFET T2 is connected to the positive terminal of the positive control power supply U1, and the second terminal of MOSFET T2 is connected to the positive control circuit resistor R1; a protection unit is connected in parallel between the current-limiting resistor R12 and the gate of MOSFET T2, the protection unit including a diode D1 and a current-limiting resistor R11; the gate of MOSFET T3 is connected to the output of the second control unit, the second terminal of MOSFET T3 shares a common ground with the voltage divider sampling unit, and the third terminal of MOSFET T3 is connected between the negative control circuit resistor R3 and the voltage divider sampling unit; the positive terminal of the negative control power supply U2 is connected in series with the diode D2 and the negative control circuit resistor R3.

[0020] Furthermore, the voltage divider sampling unit includes a voltage divider resistor R4 and a voltage divider resistor R5 connected in series. One end of the voltage divider resistor R5 is grounded, and the other end is used to set the sampling point A.

[0021] Compared with existing technologies, the above technical solution has the following advantages:

[0022] 1. It can effectively monitor the voltage values ​​V1 and / or V2 at voltage sampling point A, and then identify the type of fault at the positive and negative control terminals of the exploding fuse by combining the voltage values ​​of V1 and / or V2 with the preset voltage value and the correspondence between the fault.

[0023] 2. It can accurately and effectively locate the fault location of the explosive fuse control circuit, making it convenient to troubleshoot the fault in a timely manner and greatly improving the reliability of the explosive fuse. Attached Figure Description

[0024] Figure 1 A flowchart of the fault detection method for the control terminal of the exploding fuse in accordance with the present invention;

[0025] Figure 2 A circuit diagram of the fault detection system for the control terminal of the exploding fuse conforming to the present invention;

[0026] Figure 3 An equivalent circuit diagram for a diagnostic scenario according to the present invention;

[0027] Figure 4 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0028] Figure 5 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0029] Figure 6 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0030] Figure 7 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0031] Figure 8 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0032] Figure 9 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0033] Figure 10 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0034] Figure 11 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0035] Figure 12 An equivalent circuit diagram for another diagnostic scenario according to the present invention;

[0036] Figure label:

[0037] 1-Positive control terminal module, 2-Negative control terminal module, 3-Sampling and diagnostic module. Detailed Implementation

[0038] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0039] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses consistent with some aspects of this disclosure as detailed in the appended claims.

[0040] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0041] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another.

[0042] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or the connection between the cavities of two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0044] This invention provides a method for detecting faults in the control terminal of an exploding fuse, see reference. Figure 1 The method for detecting a fault in the control terminal of an exploding fuse includes: activating the first detection circuit; connecting the negative control terminal module 1, the negative control terminal main circuit resistor R3 in series with the voltage divider sampling unit; and connecting the equivalent resistance Rp of the exploding fuse and the parallel resistance R2 in parallel with the voltage divider sampling unit.

[0045] See Figure 2 The diagram shows a circuit schematic of a preferred embodiment of a pyro-fuse control terminal fault detection system according to the present invention, including a positive control terminal module 1, a negative control terminal module 2, and a sampling and diagnostic module 3. The sampling and diagnostic module 3 includes a positive control terminal main circuit resistor R1, a negative control terminal main circuit resistor R3, a parallel resistor R2, a voltage divider sampling unit, and a diagnostic unit. One end of the voltage divider sampling unit is connected to the positive control terminal module through the positive control terminal main circuit resistor R1, and the other end is connected to the negative control terminal module through the negative control terminal main circuit resistor R3. A parallel resistor R2 is connected between R1 and R3, and the parallel resistor R2 is connected in parallel between the positive and negative control terminals of the pyro-fuse. The positive control terminal module 1 includes a positive control terminal power supply U1, a first control unit, and MOSFETs T1 and T2. The negative control terminal module includes a negative control terminal power supply U2, a second control unit, and MOSFET T3. The first control unit sets the high-side control level IO_H to low level, turning off MOSFET T1. When MOSFET T1 is turned off, MOSFET T2 is also turned off. The second control unit sets the low-side control level IO_L to low level, turning off MOSFET T3. Thus, a first detection circuit is formed. The first detection circuit is composed of the negative control terminal power supply U2 in the negative control terminal module 1, the negative control terminal main circuit resistor R3 connected in series with the voltage divider sampling unit, and the equivalent resistance Rp of the explosion fuse and the parallel resistor R2 connected in parallel with the voltage divider sampling unit.

[0046] The voltage value V1 at sampling point A of the voltage divider sampling unit is detected. In this embodiment, voltage divider resistors R4 and R5 are connected in series in the voltage divider sampling unit. One end of the voltage divider resistor R5 is grounded, and the other end is set as sampling point A. That is, the voltage value detected at sampling point A is the voltage across the voltage divider resistor R5. Sampling point A is connected to a diagnostic unit, and the diagnostic unit detects the voltage value at sampling point A.

[0047] Calculate the range of the first voltage diagnostic value for sampling point A under different first-type fault conditions.

[0048] Based on the equivalent circuit under different first-type fault conditions, the voltage value range of the sampling point A under that condition is calculated and marked as the first voltage diagnostic value range.

[0049] Determine whether the voltage value V1 is within the first voltage diagnostic value range, and diagnose whether there is a first type of fault corresponding to the first voltage diagnostic value range at the explosion fuse control terminal.

[0050] Detect the voltage value V1 at the sampling point A. If there is a short circuit to the power supply negative pole fault at the negative control terminal of the explosion fuse, the equivalent circuit is as Figure 3 shown. Among them, at this time, the theoretical voltage value at the sampling point A should be 0V. Mark 0V as the diagnostic voltage value V0, add the redundancy a set in the system. If it is detected that V1 < V0 + a, then diagnose that there is a short circuit to the power supply negative pole fault at the negative control terminal of the explosion fuse; otherwise, diagnose that there is no such fault.

[0051] If there is a short circuit to the power supply negative pole fault at the positive control terminal of the explosion fuse, the equivalent circuit is as Figure 4 shown. The maximum voltage value of the power supply U2 at the negative control terminal is U2_max, and the equivalent resistance value of the explosion fuse when it has not failed is Rp. Since Rp is at the Ω level, while R2, R4, and R5 are all at the KΩ level, and Rp is much smaller than R2, R4, and R5, the equivalent resistance of the parallel connection of Rp, R2, and R4 + R5 ≈ Rp. Calculate the voltage across Rp as U2 * (Rp / (Rp + R3)). At this time, the maximum value of V1 is U2_max * (Rp / (Rp + R3)) * (R5 / (R4 + R5)). Mark the maximum value of this V1 as the diagnostic voltage value Va, and obtain Equation 1: Va = U2_max * (Rp / (Rp + R3)) * (R5 / (R4 + R5)); if it is detected that V1 < Va, then diagnose that there is a short circuit to the power supply negative pole fault at the positive control terminal of the explosion fuse; otherwise, diagnose that there is no such fault.

[0052] If there is a short circuit to the power supply negative pole fault at the positive control terminal of the explosion fuse and there is an open circuit fault between the positive control terminal and the negative control terminal, the equivalent circuit is as Figure 5 shown. The equivalent resistance of the parallel connection of R4 + R5 and R2 is Rb. At this time, the maximum value of V1 is U2_max * (Rb / (Rb + R3)) * (R5 / (R4 + R5)). Mark the maximum value of this V1 as the diagnostic voltage value Vb, and obtain Equation 2: Vb = U2_max * (Rp / (Rp + R3)) * (R5 / (R4 + R5)); if it is detected that V1 < Vb, then diagnose that there is a short circuit to the power supply negative pole fault at the positive control terminal of the explosion fuse and there is an open circuit fault between the positive control terminal and the negative control terminal; otherwise, diagnose that there is no such fault.

[0053] If there is no short circuit to the power supply positive pole fault and / or short circuit to the power supply positive pole fault at the positive control terminal and the negative control terminal of the explosion fuse, the equivalent circuit is as Figure 6As shown, the minimum value of V1 is U2_min*(R5 / (R3+R4+R5))-a, and the maximum value is U2_max*(R5 / (R3+R4+R5))+a, where a is the redundancy set by the system. The minimum value of V1 is marked as the diagnostic voltage value Vc, and the maximum value is marked as the diagnostic voltage value Vd, resulting in Equation 3: Vc=U2_min*(R5 / (R3+R4+R5))-a and Equation 4: Vd=U2_max*(R5 / (R3+R4+R5))+a; if Vc≤V1≤Vd is detected, then it is diagnosed that there is no short power supply positive terminal fault and / or short power supply positive terminal fault at the positive and negative control terminals of the explosion fuse.

[0054] If there is a short circuit fault at the positive control terminal of the exploding fuse and an open circuit fault between the positive and negative control terminals, then when the open circuit resistance is equivalent to infinity, the equivalent circuit is as follows: Figure 7 As shown, the minimum value of V1 can be calculated as (R5 / (R4+R5))*(U2_min / R3+U1_min / R2) / (1 / (R4+R5)+1 / R2+1 / R3). When the open-circuit resistance is equivalent to 10KΩ (10KΩ is a commonly used empirical value in this field), the equivalent circuit is as follows. Figure 8 As shown, the maximum value of V1 can be calculated as (R5 / (R4+R5))*(U2_max / R3+U1_max / Rb1) / (1 / (R4+R5)+1 / Rb1+1 / R3), where Rb1 is the equivalent parallel resistance of R2 and the 10KΩ resistor. The minimum value of V1 at this time is marked as the diagnostic voltage value VPsb_min, and the maximum value is marked as the diagnostic voltage value VPsb_max, resulting in Equation 5: VPsb_min=(R5 / (R4+R5))*(U2_min / R3+U1_min / R2) / (1 / (R4+R5)+1 / R2+1 / R3) and Equation 6: VPsb_max=(R5 / (R4+R5))*(U2_max / R3+U1_max / Rb1) / (1 / (R4+R5)+1 / Rb1+1 / R3); if VPsb_min<V1<VPsb_max is detected, then there is a short power supply positive terminal fault at the positive control terminal of the diagnostic explosion fuse and an open circuit fault between the positive control terminal and the negative control terminal;

[0055] If there is a short circuit to the positive control terminal of the exploding fuse, the equivalent circuit is as follows: Figure 9As shown, since Rp is much smaller than R2, the equivalent resistance of R2 and Rp in parallel is approximately equal to Rp. The minimum voltage value of the positive control terminal power supply is U1_min. At this time, the minimum value of V1 is U1_min*(R5 / (Rp+R4+R5)). Marking this minimum value of V1 as the diagnostic voltage value Ve, we get Equation 6: Ve=U1_min*(R5 / (Rp+R4+R5)). If there is a short circuit fault at the negative control terminal of the exploding fuse, the equivalent circuit is as follows. Figure 10 As shown, the maximum voltage of the positive control terminal power supply is U1_max. At this time, the maximum value of V1 is U1_max*(R5 / (R4+R5)). This maximum value of V1 is marked as the diagnostic voltage value Vf, resulting in Equation 7: Vf=U1_max*(R5 / (R4+R5)). Since Rp is very small, it is difficult to distinguish whether there is a short power supply positive terminal fault or a short power supply positive terminal fault at the positive control terminal or the negative control terminal of the explosion fuse. Therefore, if Ve≤V1≤Vf is detected, a short power supply positive terminal fault is diagnosed at the positive control terminal and / or the negative control terminal of the explosion fuse.

[0056] The voltage diagnostic values ​​V0, Va, Vb, Vc, Vd, VPsb_max, VPsb_min, Ve, and Vf correspond one-to-one with the first type of fault mentioned above, forming the first correspondence relationship as shown in Table 1. After detecting the voltage value V1 at sampling point A, the presence of a corresponding first type of fault in the exploding fuse is diagnosed according to the first correspondence relationship.

[0057]

[0058] Table 1

[0059] Preferably, in this embodiment, in addition to diagnosing all of the above-mentioned first type of faults, it also includes the detection of a second type of fault, including:

[0060] The second detection circuit is activated. The positive control terminal module, the positive control terminal main circuit resistor R1, the voltage divider sampling unit, and the parallel resistor R2 are connected in series. The equivalent resistance Rp of the explosion fuse is connected in parallel with the parallel resistor R2.

[0061] Continue reading Figure 2 The first control unit sets the high-side control level IO_H to high level, turns on MOSFET T1, and when MOSFET T1 is turned on, MOSFET T2 is also turned on. The second control unit sets the low-side control level IO_L to low level, turns off MOSFET T3, thereby forming a second detection circuit. The second detection circuit is composed of the positive control terminal power supply U1 of the positive control terminal 1, the positive control terminal main circuit resistor R1 and the voltage divider sampling unit, and the parallel resistor R2 connected in series. The equivalent resistance Rp of the explosion fuse is connected in parallel with the parallel resistor R2.

[0062] The voltage value V2 at sampling point A of the voltage divider sampling unit is detected.

[0063] Calculate the range of the second voltage diagnostic value for sampling point A under different second-type fault scenarios.

[0064] Based on the equivalent circuit under different second-type fault conditions, the voltage value range of the sampling point A under that condition is calculated and marked as the second voltage diagnostic value range.

[0065] Determine whether the voltage value V2 is within the second voltage diagnostic value range, and diagnose whether the control terminal of the exploding fuse has a second type of fault corresponding to the second voltage diagnostic value range.

[0066] If there is no open circuit fault between the positive and negative control terminals of the exploding fuse, and there is no short circuit fault between the positive and negative control terminals, then the equivalent circuit is as follows: Figure 11 As shown, since Rp is much smaller than R2, the equivalent resistance of R2 and Rp in parallel is approximately equal to Rp. At this time, the minimum value of V2 is U1_min*R5 / (R1+Rp+R4+R5)-a, and the maximum value is U1_max*R5 / (R1+Rp+R4+R5)+a, where a is the redundancy set by the system. The minimum value of V2 at this time is marked as the diagnostic voltage value Vg, resulting in equation 8: Vg=U1_min*R5 / (R1+Rp+R4+R5)-a; the maximum value of V2 at this time is marked as the diagnostic voltage value Vh, resulting in equation 9: Vh=U1_max*R5 / (R1+Rp+R4+R5)+a; if Vg≤V2≤Vh is detected, then there is no open circuit fault between the positive and negative control terminals of the diagnostic explosion fuse, and there is no short-circuit fault between the positive and negative control terminals.

[0067] If there is an open circuit fault between the positive and negative control terminals of the explosion fuse, the equivalent circuit is as follows: Figure 12 As shown, the minimum value of V2 at this time is U1_min*R5 / (R1+R2+R4+R5), and the maximum value is U1_max*R5 / (R1+R2+R4+R5). The minimum value of V2 at this time is marked as the diagnostic voltage value Vi, resulting in Equation 10: Vi=U1_min*R5 / (R1+R2+R4+R5); The maximum value of V2 at this time is marked as the diagnostic voltage value Vj, resulting in Equation 11: Vj=U1_max*R5 / (R1+R2+R4+R5); If Vi≤V2≤Vj is detected, then an open circuit fault is diagnosed between the positive and negative control terminals of the explosion fuse.

[0068] The voltage diagnostic values ​​Vg, Vh, Vi, and Vj mentioned above correspond one-to-one with the second type of fault mentioned above, forming the second correspondence relationship as shown in Table 2. After detecting the voltage value V2 at sampling point A, the second correspondence relationship is used to diagnose whether the explosion fuse has a corresponding second type of fault.

[0069]

[0070] Table 2

[0071] When the voltage value V1 is not within the first voltage diagnostic value range and the voltage value V2 is not within the second voltage diagnostic value range, it is diagnosed that there is another fault in the control terminal of the explosion fuse. The other fault is a fault in the control terminal of the explosion fuse other than the first type of fault and the second type of fault.

[0072] Preferably, in this embodiment, the first detection circuit is first activated to perform the first type of fault detection, and after the first type of fault detection is completed, the second detection circuit is activated to perform the second type of fault detection. It should be understood that in other embodiments, the second detection circuit may be activated first to perform the second type of fault detection, and after the second type of fault detection is completed, the first detection circuit may be activated to perform the first type of fault detection.

[0073] Preferably, if a fault is diagnosed in the control terminal of the explosion fuse, the fault is eliminated before testing continues until all faults are detected.

[0074] More preferably, in this embodiment, the fault detection of the control terminal of the exploding fuse is performed sequentially according to the faults corresponding to the voltage diagnostic values ​​V0, Va, Vb, Vc, Vd, VPsb_max, VPsb_min, Ve, Vf, Vg, Vh, Vi, and Vj. That is, first, it is detected whether there is a short power supply negative terminal fault at the negative control terminal of the exploding fuse corresponding to the voltage diagnostic value V0. If the fault is diagnosed at the control terminal of the exploding fuse, the fault detection is paused. After the short power supply negative terminal fault at the negative control terminal of the exploding fuse is eliminated, it is detected whether there is a short power supply negative terminal fault at the positive control terminal of the exploding fuse corresponding to the voltage diagnostic value Va. If the voltage value at sampling point A does not meet the diagnostic condition of voltage diagnostic value V0, it is diagnosed that the exploding fuse does not have the fault. It is then detected whether there is a short power supply negative terminal fault at the positive control terminal of the exploding fuse corresponding to the voltage diagnostic value Va, and so on, until all fault detections are completed.

[0075] It should be understood that, since there is a difference between the actual voltage and the nominal voltage of the voltage source, the calculation formula in this embodiment uses the minimum value U1_min and the maximum value U1_max of the positive control terminal voltage source U1, and the minimum value U2_min and the maximum value U2_max of the negative control terminal voltage source U2.

[0076] This invention also provides a fault detection system for the control terminal of an exploding fuse, see reference. Figure 2 The system comprises a positive control terminal module 1, a negative control terminal module 2, a positive control terminal main circuit resistor R1, a negative control terminal main circuit resistor R3, a parallel resistor R2, a voltage divider sampling unit, and a diagnostic unit. One end of the voltage divider sampling unit is connected to the positive control terminal module 1 via the positive control terminal main circuit resistor R1, and the other end is connected to the negative control terminal module 2 via the negative control terminal main circuit resistor R3. A parallel resistor R2 is connected between R1 and R3, and is connected in parallel between the positive and negative control terminals of the fuse. The system includes a first detection circuit, which is formed by connecting the negative control terminal module 2, the negative control terminal main circuit resistor R3, and the voltage divider sampling unit in series. The equivalent resistance Rp of the fuse control terminal is... The voltage divider sampling unit is formed by connecting the parallel resistor R2 and the voltage divider sampling unit in parallel. The positive control module and the negative control terminal module are used to power the system and control the conduction and shutdown of the first detection circuit. One end of the voltage divider sampling unit is grounded, and the other end is connected to the negative control terminal main circuit resistor R3. The voltage divider sampling unit is set with sampling point A, and sampling point A is connected to the input terminal of the diagnostic unit. The diagnostic unit is used to detect the voltage value V1 of sampling point A, calculate the first voltage diagnostic value range of sampling point A under different first type of fault conditions, determine whether the voltage value V1 is within the first voltage diagnostic value range, and diagnose whether the first type of fault corresponding to the first voltage diagnostic value range exists at the control terminal of the exploding fuse.

[0077] Preferably, the fault detection system for the control terminal of the exploding fuse further includes a second detection circuit. The second detection circuit is formed by connecting the positive control terminal module 1, the positive control terminal main circuit resistor R1 and the voltage divider sampling unit, and the parallel resistor R2 in series. The exploding fuse is connected in parallel with the parallel resistor R2. The positive control module 1 and the negative control terminal module 2 are also used to control the conduction and shutdown of the second detection circuit. The sampling point A is also used to detect the voltage value V2.

[0078] Preferably, see Figure 2In this embodiment, the positive control module 1 includes a positive control power supply U1, a first control unit, and MOSFETs T1 and T2. The first control unit is used to control the on and off states of MOSFET T1. The output terminal of MOSFET T1 is connected to MOSFET T2 and is used to control the on and off states of MOSFET T1. The negative control module 2 includes a negative control power supply U2, a second control unit, and MOSFET T3. The second control unit is used to control the on and off states of MOSFET T3. MOSFETs T1, T2, and T3 are used to: conduct a first detection circuit when MOSFETs T1, T2, and T3 are off; and conduct a second detection circuit when MOSFETs T1 and T2 are on and MOSFET T3 is off.

[0079] Preferably, see below. Figure 2 The gate of MOSFET T1 is connected to the output of the first control unit, the second terminal of MOSFET T1 is grounded, and the third terminal of MOSFET T1 is connected in series with the current-limiting resistor R12 and the gate of MOSFET T2. The first terminal of MOSFET T2 is connected to the positive terminal of the positive control power supply U1, and the second terminal of MOSFET T2 is connected to the positive control circuit resistor R1. A protection unit is connected in parallel between the current-limiting resistor R12 and the gate of MOSFET T2, and the protection unit includes a diode D1 and a current-limiting resistor R11. The gate of MOSFET T3 is connected to the output of the second control unit, the second terminal of MOSFET T3 shares a common ground with the voltage divider sampling unit, and the third terminal of MOSFET T3 is connected between the negative control circuit resistor R3 and the voltage divider sampling unit. The positive terminal of the negative control power supply U2 is connected in series with the diode D2 and the negative control circuit resistor R3.

[0080] When performing the first type of fault detection, the first control unit sets the high-side control level IO_H to low, turning off MOSFET T1. When MOSFET T1 is turned off, MOSFET T2 is also turned off. The second control unit sets the low-side control level IO_L to low, turning off MOSFET T3, thus forming a conducting first detection circuit. When performing the second type of fault detection, the first control unit sets the high-side control level IO_H to high, turning on MOSFET T1. When MOSFET T1 is turned on, MOSFET T2 is also turned on. The second control unit sets the low-side control level IO_L to low, turning off MOSFET T3, thus forming a conducting second detection circuit.

[0081] The fault detection system for the control terminal of the exploding fuse in this embodiment is applied to the battery management system of a new energy vehicle. The positive control terminal power supply U1 is the power supply for the control circuit of the vehicle BMS (Battery Management System), and the negative control terminal power supply U2 is a DC power supply with a nominal value of 5V. The first control unit and the second control unit are two independently operating MCUs. The MCU sets a high level or a low level to control the turn-off and turn-on of the MOS transistor.

[0082] Preferably, the voltage divider sampling unit includes a voltage divider resistor R4 and a voltage divider resistor R5 connected in series. One end of the voltage divider resistor R5 is grounded, and the other end is used to set the sampling point A.

[0083] Preferably, the selection of the main circuit resistor R1 at the positive control terminal should ensure that the control current of the Pyro-Fuse can reach the minimum value of the trigger current. The value of the parallel resistor R2 should be much larger than that of R1, and the values ​​of R4+R5 should be close to those of R2. More preferably, R1 is in the Ω range, and R2, R3, R4, and R5 are in the KΩ range.

[0084] In this embodiment, the MOSFET is turned on and off by the independently operating first and second control units, which conduct the expected detection circuit and detect the voltage at sampling point A. Based on the first and second correspondences mentioned above, the system diagnoses whether there is a fault in the positive and negative control terminals of the fuse and what kind of fault it is. This accurately and effectively locates the location and type of fault in the fuse control circuit, making it convenient to troubleshoot the fault in a timely manner and greatly improving the reliability of the fuse.

[0085] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method of detecting a control terminal fault of an explosion fuse, characterized by, Comprising: First type fault detection: Turn on the first detection circuit, The negative control end module, the negative control end resistance R3 and the voltage division sampling unit are connected in series, the equivalent resistance Rp of the explosion fuse control end and the parallel resistance R2 are connected in parallel with the voltage division sampling unit respectively; Detect the voltage value V1 of the sampling point A of the voltage division sampling unit, Calculate the first voltage diagnostic value interval of the sampling point A under different first type fault conditions, Determine whether the voltage value V1 is within the first voltage diagnostic value interval, and diagnose whether the first type fault corresponding to the first voltage diagnostic value interval exists in the explosion fuse control end; The first type fault detection comprises: Calculate the diagnostic voltage value V0 and Va, V0=0V, Va=U2_max*(Rp / (Rp+R3))*(R5 / (R4+R5)), Where U2_max is the maximum voltage value of the negative control end power supply U2, Rp is the equivalent resistance value of the explosion fuse control end when no fault occurs, R4 and R5 are the resistance values of the voltage division resistor R4 and the voltage division resistor R5 connected in series in the voltage division sampling unit, one end of the voltage division resistor R5 is grounded, and the other end is provided with the sampling point A; When V1 Where a is the redundancy set by the system.

2. The explosion fuse control end fault detection method of claim 1, further comprising: Second type fault detection: Turn on the second detection circuit, the positive control end module, the positive control end resistance R1, the voltage division sampling unit and the parallel resistance R2 are connected in series, and the equivalent resistance Rp of the explosion fuse control end is connected in parallel with the parallel resistance R2; Detect the voltage value V2 of the sampling point A of the voltage division sampling unit, Calculate the second voltage diagnostic value interval of the sampling point A under different second type fault conditions, Determine whether the voltage value V2 is within the second voltage diagnostic value interval, and diagnose whether the second type fault corresponding to the second voltage diagnostic value interval exists in the explosion fuse control end; When the voltage value V1 is not within the first voltage diagnostic value interval and the voltage value V2 is not within the second voltage diagnostic value interval, diagnose that other faults exist in the explosion fuse control end, and the other faults are explosion fuse control end faults other than the first type fault and the second type fault.

3. The explosion fuse control end fault detection method of claim 2, wherein the first type fault detection further comprises: Calculate the diagnostic voltage value Vb, Vb=U2_max*(Rb / (Rb+R3))*(R5 / (R4+R5)), where Rb is the parallel equivalent resistance value of R4+R5 and R2; When V1 4. The explosion fuse control end fault detection method of claim 3, wherein the first type fault detection further comprises: ​ ​ calculating voltage diagnostic value Vc and Vd, Vc = U2_min * (R5 / (R3 + R4 + R5)) - a, Vd = U2_max * (R5 / (R3 + R4 + R5)) + a; wherein U2_min is the minimum voltage value of the negative control terminal power supply; when Vc ≤ V1 ≤ Vd, diagnosing that the positive control terminal and the negative control terminal of the explosion fuse do not exist short power supply positive fault and / or short power supply negative fault.

5. The explosion fuse control terminal fault detection method of claim 4, wherein the first type fault detection further comprises: calculating voltage diagnostic value VPsb_max and VPsb_min, VPsb_min = (R5 / (R4 + R5)) * (U2_min / R3 + U1_min / R2) / (1 / (R4 + R5) + 1 / R2 + 1 / R3), VPsb_max = (R5 / (R4 + R5)) * (U2_max / R3 + U1_max / Rb1) / (1 / (R4 + R5) + 1 / Rb1 + 1 / R3), wherein Rb1 is the parallel equivalent resistance value of R2 and 10KΩ resistance; when VPsb_min < V1 < VPsb_max, diagnosing that the positive control terminal of the explosion fuse exists short power supply positive fault and that there exists open circuit fault between the positive control terminal and the negative control terminal.

6. The explosion fuse control terminal fault detection method of claim 5, wherein the first type fault detection further comprises: calculating voltage diagnostic value Ve and Vf, Ve = U1_min * (R5 / (Rp + R4 + R5)), Vf = U1_max * (R5 / (R4 + R5)); wherein U1_min is the minimum voltage value of the positive control terminal power supply and U1_max is the maximum voltage value of the positive control terminal power supply; when Ve ≤ V1 ≤ Vf, diagnosing that the positive control terminal and / or the negative control terminal of the explosion fuse exists short power supply positive fault.

7. The explosion fuse control terminal fault detection method of claim 6, wherein the second type fault detection comprises: calculating voltage diagnostic value Vg and Vh, Vg = U1_min * R5 / (R1 + Rp + R4 + R5) - a, Vh = U1_max * R5 / (R1 + Rp + R4 + R5) + a; when Vg ≤ V2 ≤ Vh, diagnosing that there exists no open circuit fault between the positive control terminal and the negative control terminal of the explosion fuse and that there exists no short power supply negative fault in the positive control terminal and the negative control terminal.

8. The explosion fuse control terminal fault detection method of claim 7, wherein the second type fault detection further comprises: calculating voltage diagnostic value Vi and Vj, Vi = U1_min * R5 / (R1 + R2 + R4 + R5), Vj = U1_max * R5 / (R1 + R2 + R4 + R5), when Vi ≤ V2 ≤ Vj, diagnosing that there exists open circuit fault between the positive control terminal and the negative control terminal of the explosion fuse.

9. The explosion fuse control terminal fault detection method of any one of claims 2-8, wherein ​ ​ ​ ​ The first detection circuit includes MOS transistor T1 and MOS transistor T2 controlled by the first control unit, and MOS transistor T3 controlled by the second control unit. The second detection circuit includes MOS transistor T1 and MOS transistor T2 controlled by the first control unit, and MOS transistor T3 controlled by the second control unit.

10. The method of claim 9, wherein, the first detection circuit is first turned on to perform the first type of fault detection, and then the second detection circuit is turned on to perform the second type of fault detection; or the second detection circuit is first turned on to perform the second type of fault detection, and then the first detection circuit is turned on to perform the first type of fault detection; if a fault is diagnosed in the control terminal of the explosion fuse, the fault is eliminated and then the detection is continued until all faults are detected.

11. An explosive fuse control terminal fault detection system characterized by, The device comprises: a positive control terminal module, a negative control terminal module, and a sampling diagnosis module, wherein the sampling diagnosis module comprises a positive control terminal main resistance R1, a negative control terminal main resistance R3, a parallel resistance R2, a voltage division sampling unit, and a diagnosis unit; one end of the voltage division sampling unit is connected to the positive control terminal module through the positive control terminal main resistance R1, and the other end is connected to the negative control terminal module through the negative control terminal main resistance R3, and the parallel resistance R2 is connected between the positive control terminal main resistance R1 and the negative control terminal main resistance R3; the first detection circuit is connected in series with the negative control terminal module, the negative control terminal main resistance R3, and the voltage division sampling unit, and the equivalent resistance Rp of the control terminal of the explosion fuse and the parallel resistance R2 are connected in parallel with the voltage division sampling unit; the positive control module and the negative control terminal module are used to supply power to the system and control the turn-on and turn-off of the first detection circuit; one end of the voltage division sampling unit is grounded, and the other end is connected to the negative control terminal main resistance R3; the voltage division sampling unit is provided with a sampling point A, and the sampling point A is connected to the input end of the diagnosis unit; the diagnosis unit is used to detect the voltage value V1 of the sampling point A, calculate the first voltage diagnosis value interval of the sampling point A in different first type fault situations, judge whether the voltage value V1 is within the first voltage diagnosis value interval, and diagnose whether the first type fault corresponding to the first voltage diagnosis value interval exists in the control terminal of the explosion fuse; the first type fault detection comprises: calculating the diagnosis voltage value V0 and Va, V0 = 0V, Va = U2_max*(Rp / (Rp+R3))*(R5 / (R4+R5)), wherein U2_max is the maximum voltage value of the negative control terminal power supply U2, Rp is the equivalent resistance value of the control terminal of the explosion fuse when no fault occurs, R4 and R5 are the resistance values of the voltage division resistors R4 and R5 connected in series in the voltage division sampling unit, one end of the voltage division resistor R5 is grounded, and the other end is provided with the sampling point A. When V1 < V0 + a, it is diagnosed that there is a short power negative pole fault in the negative control end of the explosion fuse; when V1 < Va, it is diagnosed that there is a short power negative pole fault in the positive control end of the explosion fuse. Wherein, a is a redundancy set by the system.

12. The explosion fuse control end fault detection system according to claim 11, wherein, a second detection loop is further included, the second detection loop is connected in series by the positive control end module, the positive control end dry circuit resistance R1 and the voltage division sampling unit, a parallel resistance R2 is connected in parallel with the explosion fuse control end equivalent resistance Rp and the parallel resistance R2, the positive control module and the negative control end module are further used for controlling the turn-on and turn-off of the second detection loop, and the diagnosis unit is further used for detecting a voltage value V2 of the sampling point A, calculating a second voltage diagnosis value interval of the sampling point A in different first type fault situations, judging whether the voltage value V1 is in the first voltage diagnosis value interval, and diagnosing whether the explosion fuse control end exists a second type fault corresponding to the second voltage diagnosis value interval.

13. The explosion fuse control end fault detection system according to claim 12, wherein, the positive control end module includes a positive control end power supply U1, a first control unit and MOS tubes T1 and T2, the first control unit is used for controlling the turn-on and turn-off of the MOS tube T1, and the output end of the MOS tube T1 is connected to the MOS tube T2, and is used for controlling the turn-on and turn-off of the MOS tube T1; the negative control end module includes a negative control end power supply U2, a second control unit and a MOS tube T3, and the second control unit is used for controlling the turn-on and turn-off of the MOS tube T3; wherein, the MOS tube T1, the MOS tube T2 and the MOS tube T3 are used for: when the MOS tube T1, the MOS tube T2 and the MOS tube T3 are turned off, the first detection loop is turned on, when the MOS tube T1 and the MOS tube T2 are turned on and the MOS tube T3 is turned off, the second detection loop is turned on.

14. The explosion fuse control end fault detection system according to claim 13, wherein, the gate end of the MOS tube T1 is connected to the output end of the first control unit, the second end of the MOS tube T1 is grounded, and the third end of the MOS tube T1 is connected in series with a current limiting resistance R12 and the gate end of the MOS tube T2 in turn; the first end of the MOS tube T2 is connected to the positive pole of the positive control end power supply U1, and the second end of the MOS tube T2 is connected to the positive control end dry circuit resistance R1; a protection unit is connected in parallel between the current limiting resistance R12 and the gate end of the MOS tube T2, and the protection unit includes a diode D1 and a current limiting resistance R11; the gate end of the MOS tube T3 is connected to the output end of the second control unit, the second end of the MOS tube T3 is grounded with the voltage division sampling unit, and the third end of the MOS tube T3 is connected between the negative control end dry circuit resistance R3 and the voltage division sampling unit; the positive pole of the negative control end power supply U2 is connected in series with a diode D2 and the negative control end dry circuit resistance R3 in turn.

15. The control terminal fault detection system for a blasting fuse of claim 14, wherein, The voltage division sampling unit comprises a voltage division resistor R4 and a voltage division resistor R5 connected in series, one end of the voltage division resistor R5 is grounded, and the other end is provided with the sampling point A.

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