LLC circuit detection method, on-board charger, and vehicle

Abstract

The present disclosure relates to an LLC circuit detection method, an on-board charger, and a vehicle. The method includes: in response to soft-starting the LLC circuit and performing a self-test, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from multiple acquisition points, where the acquisition points correspond to the primary bridge arm and / or the secondary bridge arm of the LLC circuit; and performing a joint judgment based on the electrical signals acquired at the multiple acquisition points to determine whether a switch in the LLC circuit has failed, thereby improving the efficiency and safety of LLC circuit fault detection.

Description

Technical Field

[0001] The present disclosure relates to the technical field of circuit detection, and in particular, to an LLC circuit detection method, an on-board charger, and a vehicle. Background Art

[0002] With the commercialization of electric vehicles, onboard chargers have become a critical component in electric vehicles. LLC (Resonant Converter) circuits are widely used in onboard chargers due to their high efficiency and high power density. However, because the switches in LLC circuits operate at high frequencies, their failure rate is relatively high. Once a switch fails, it directly affects the stability and reliability of the entire circuit. Traditional LLC circuit detection methods typically rely on a single detection point, determining the circuit's operating status by measuring the voltage or current signal at that point. However, this method can only detect localized fault information in the circuit and cannot fully and accurately determine the operating status of the entire circuit. In particular, when multiple switches fail simultaneously, traditional detection methods are often unable to effectively identify them. Summary of the Invention

[0003] The present disclosure aims to provide an LLC circuit detection method, an on-board charger, and a vehicle.

[0004] To achieve the above objectives, the present disclosure provides an LLC circuit detection method, the method comprising:

[0005] In response to the LLC circuit soft-starting and performing a self-test, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points, where the acquisition points correspond to a primary bridge arm and / or a secondary bridge arm of the LLC circuit;

[0006] A joint judgment is performed based on the electrical signals collected by the multiple collection points to determine whether a switch tube in the LLC circuit fails.

[0007] Optionally, the primary bridge arm includes a first bridge arm and a second bridge arm, the secondary bridge arm includes a third bridge arm and a fourth bridge arm, and the multiple collection points include at least one of the following positions:

[0008] a first collection point, the first collection point corresponding to the first bridge arm;

[0009] a second collection point, the second collection point corresponding to the second bridge arm;

[0010] a third collection point, the third collection point corresponding to the first bridge arm and / or the second bridge arm;

[0011] A fourth collection point, the fourth collection point corresponds to the third bridge arm and / or the fourth bridge arm.

[0012] Optionally, the electrical signals collected by the multiple collection points include at least one of the following electrical signals:

[0013] a first voltage signal collected through the first collection point, a second voltage signal collected through the second collection point, a first current signal collected through the third collection point, and a second current signal collected through the fourth collection point.

[0014] Optionally, the switch tubes of the LLC circuit include a switch tube in the primary bridge arm and a switch tube in the secondary bridge arm, and controlling the on and off of the switch tubes in the LLC circuit to acquire electrical signals from the plurality of acquisition points includes:

[0015] Turning off all switching tubes in the primary bridge arm and the secondary bridge arm of the LLC circuit, and acquiring the first voltage signal, the second voltage signal, and the first current signal;

[0016] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0017] If the first voltage signal or the second voltage signal is not equal to zero, and the first current signal is not equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are in a fault state, or the upper bridge arm switch tube of the second bridge arm and the lower bridge arm switch tube of the first bridge arm are faulty;

[0018] If the first voltage signal or the second voltage signal is equal to zero, and the first current signal is equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0019] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0020] Turning on the upper bridge arm switch of the first bridge arm, and turning off the lower bridge arm switch of the first bridge arm, the upper bridge arm switch and the lower bridge arm switch of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal;

[0021] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0022] If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, and the second voltage signal is equal to zero, the first current signal is not equal to zero, and the first current signal is proportional to the second current signal, it is determined that the lower bridge arm switch tube of the second bridge arm is faulty;

[0023] If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm is faulty;

[0024] If the first voltage signal is not equal to zero, and the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0025] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0026] turning on the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm, and turning off the lower bridge arm switch tube of the first bridge arm and the upper bridge arm switch tube of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal;

[0027] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0028] If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm is faulty;

[0029] If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, it is determined that the upper bridge arm switch tube of the third bridge arm or the lower bridge arm switch tube of the fourth bridge arm has a fault;

[0030] If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, it is determined that the upper bridge arm switch tube of the first bridge arm, the lower bridge arm switch tube of the second bridge arm, the upper bridge arm switch tube of the third bridge arm, and the lower bridge arm switch tube of the fourth bridge arm are not faulty.

[0031] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0032] turning on the upper bridge arm switch tube of the second bridge arm, and turning off the upper bridge arm switch tube and the lower bridge arm switch tube of the first bridge arm, as well as the lower bridge arm switch tube of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal;

[0033] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0034] If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm is faulty;

[0035] If the first voltage signal is equal to zero, and the second voltage signal, the first current signal, and the second current signal are not equal to zero, it is determined that the lower bridge arm switch tube of the first bridge arm is faulty;

[0036] If the difference between the second voltage signal and the bus voltage is less than a preset error threshold, and the first voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0037] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0038] turning on the lower bridge arm switch tube of the first bridge arm and the upper bridge arm switch tube of the second bridge arm, and turning off the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal;

[0039] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0040] If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, and the first current signal and the second current signal are equal to zero, it is determined that the lower bridge arm switch tube of the first bridge arm is faulty;

[0041] If the first voltage signal, the second voltage signal, the first voltage signal, and the second voltage signal are equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm is faulty;

[0042] If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, then it is determined that the lower bridge arm switch tube of the third bridge arm or the upper bridge arm switch tube of the fourth bridge arm has a fault;

[0043] If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, it is determined that the lower bridge arm switch tube of the first bridge arm, the upper bridge arm switch tube of the second bridge arm, the lower bridge arm switch tube of the third bridge arm, and the upper bridge arm switch tube of the fourth bridge arm are not faulty.

[0044] The present disclosure also provides an on-board charger, which is used to execute the LLC circuit detection method provided by the present disclosure.

[0045] The present disclosure also provides a vehicle, which is provided with an on-board charger to implement the LLC circuit detection method provided by the present disclosure.

[0046] Through the above technical solution, the fault state of the switch tube in the LLC circuit can be determined quickly and accurately, thereby increasing the detection efficiency and reliability of the LLC circuit.

[0047] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0049] Figure 1 This is a flowchart of an LLC circuit detection method proposed by an exemplary embodiment of the present disclosure.

[0050] Figure 2 FIG. 4 is a topological diagram of an LLC circuit proposed in an exemplary embodiment of the present disclosure.

[0051] Figure 3 1 is a schematic diagram of the locations of sampling points in an LLC circuit proposed in an exemplary embodiment of the present disclosure.

[0052] Figure 4 This is a flowchart of a control method of a vehicle-mounted controller proposed by an exemplary embodiment of the present disclosure.

[0053] Figure 5 The present invention provides a flowchart of charging control for a vehicle-mounted controller according to an exemplary embodiment of the present invention.

[0054] Figure 6 4 is a block diagram of an LLC circuit detection device proposed by an exemplary embodiment of the present disclosure.

[0055] Figure 7 It is a block diagram of a control device of a vehicle-mounted controller proposed by an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0056] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0057] Before introducing the LLC circuit detection method provided by the present disclosure, we first introduce the exemplary scenarios in which the present disclosure can be applied. The on-board charger of an electric vehicle generally adopts a two-stage circuit, namely, a two-stage control of a PFC (Power Factor Correction) circuit and an LLC circuit. The front-stage PFC circuit is mainly used for power factor calibration control to achieve AC-DC (Alternating Current-Direct Current) The LLC circuit in the subsequent stage is used for isolated resonant control, primarily for DC-DC conversion, enabling software switching and charging current control. In existing technologies, when the charging gun is connected to the on-board charging device, the FPC circuit is first checked. If the FPC circuit is normal, the switches in the FPC circuit are enabled. The LLC circuit's bus voltage is then tested. If the bus voltage is also normal, the LLC circuit is assumed to be normal, enabling the switches in the LLC circuit and controlling the on-board charger to charge the vehicle. However, since each switch in the LLC circuit is periodically turned on and off during charging, a failure of some of the switches in the LLC circuit can cause high currents in the charging circuit, potentially damaging the on-board charger. Furthermore, the above solution stops charging the on-board charger upon detecting a fault.

[0058] In view of this, in order to improve the detection efficiency and accuracy of the LLC circuit and the safety of the on-board charger, the present disclosure provides an LLC circuit detection method, which is applied to a controller, and the LLC circuit includes multiple collection points.

[0059] Figure 1 This is a flowchart of an LLC circuit detection method proposed by an exemplary embodiment of the present disclosure, see Figure 1 As shown, the method includes the following steps.

[0060] In step S101 , in response to the LLC circuit soft-starting and self-checking, the switching of the switch tube in the LLC circuit is controlled to acquire electrical signals from multiple acquisition points.

[0061] The acquisition points correspond to the primary bridge arm and / or the secondary bridge arm of the LLC circuit.

[0062] See also Figure 2 As shown, the LLC circuit includes a primary switch module, a resonance module and a secondary switch module, and the primary switch module is coupled to the secondary switch module through the resonance module.

[0063] Among them, the primary bridge arm is the bridge arm in the primary switch module, the secondary bridge arm is the bridge arm in the secondary switch module, and the switch tubes of the LLC circuit include switch tubes P7 to P10 in the primary bridge arm and switch tubes S1 to S4 in the secondary bridge arm.

[0064] In one embodiment, the collection point can be set corresponding to one or more bridge arms. If the collection point is set corresponding to one bridge arm, the collection point can be set in the bridge arm, before the input end of the bridge arm, after the output end of the bridge arm, or at any position between the bridge arm and another bridge arm. If the collection point is set corresponding to multiple bridge arms, the collection point can be set at the common point of the input ends or the common point of the output ends of the multiple bridge arms.

[0065] It is worth noting that the LLC circuit in the on-board charger can be a full-bridge LLC circuit or a half-bridge LLC circuit. When the charging power is low, the half-bridge LLC circuit can be used, and when the charging power is high, the full-bridge LLC circuit can be used.

[0066] In step S102, a joint judgment is performed on the electrical signals collected by the multiple collection points to determine whether a switch in the LLC circuit fails.

[0067] The electrical signal includes at least one of a voltage signal and a current signal.

[0068] In one embodiment, multiple switch tubes of the primary switch module can be turned on so that each module in the LLC circuit generates a current loop, for example, P7 and P10 are turned on, and then the current signal in each module is collected respectively, and then it can be determined whether the switch tube in the LLC circuit is faulty based on the current signal.

[0069] In another embodiment, after the LLC circuit is turned on, voltage signals at multiple points may be collected, and it may be determined whether a switch in the LLC circuit fails based on voltage differences corresponding to different points.

[0070] Through the above solution, the fault state of the switch tube in the LLC circuit can be determined quickly and accurately, thereby increasing the detection efficiency and reliability of the LLC circuit.

[0071] Optionally, the LLC circuit is a full-bridge LLC circuit, the primary bridge arm includes a first bridge arm and a second bridge arm, the secondary bridge arm includes a third bridge arm and a fourth bridge arm, and the multiple collection points include at least one of the following positions:

[0072] A first collection point, wherein the first collection point corresponds to the first bridge arm.

[0073] A second collection point, wherein the second collection point corresponds to the second bridge arm.

[0074] A third collection point, the third collection point corresponds to the first bridge arm and / or the second bridge arm.

[0075] A fourth collection point, the fourth collection point corresponds to the third bridge arm and / or the fourth bridge arm.

[0076] To more clearly describe the locations of multiple collection points, first refer to Figure 2 The LLC topology diagram shown introduces the LLC circuit.

[0077] In the primary side switch module, U1 is the bus power supply, the voltage of the bus power supply is U0, the switch tube P7 and the switch tube P8 form the first bridge arm Q1, P7 is the upper bridge arm switch tube of the first bridge arm Q1, P8 is the lower bridge arm switch tube of the first bridge arm Q1, the switch tube P9 and the switch tube P10 form the second bridge arm Q2, P9 is the upper bridge arm switch tube of the second bridge arm Q2, and P10 is the lower bridge arm switch tube of the second bridge arm Q2. Among them, C7 to C10 are the junction capacitances of the switch tubes P7 to P10 respectively.

[0078] In the resonant module, L r1 is the primary inductance, C r1 is the primary capacitance, L m is the excitation inductor, T1 is the transformer, and the turns ratio of the primary and secondary coils of T1 is n p / n s , n p is the number of turns of the primary coil, n s is the number of turns of the secondary coil.

[0079] It is worth noting that, when there is no abnormality in the LLC circuit, the ratio between the current in the primary coil and the current in the secondary coil is inversely proportional to the turns ratio of T1.

[0080] In the secondary side switch module, C o1 is the high-voltage output capacitor, R is the output load, the switch tube S1 and the switch tube S2 form the third bridge arm Q3, S1 is the upper bridge arm switch tube of the third bridge arm Q3, S2 is the lower bridge arm switch tube of the third bridge arm Q3, the switch tube S3 and the switch tube S4 form the fourth bridge arm Q4, S3 is the upper bridge arm switch tube of the fourth bridge arm Q4, and S4 is the lower bridge arm switch tube of the fourth bridge arm Q4. Among them, C11 to C14 are the junction capacitances of the switch tubes S1 to S4 respectively.

[0081] In one embodiment, the first collection point is the neutral point of the first bridge arm in the primary switch module.

[0082] The first acquisition point is the acquisition point of the voltage signal, see Figure 3 As shown, the first signal collection point is point A, which is located between the upper bridge arm switch tube P7 and the lower bridge arm switch tube P8 of the first bridge arm, and the resonant module is coupled with the first bridge arm of the primary switch module through point A. The first voltage signal U can be collected through point A. a .

[0083] For example, the second collection point is the neutral point of the second bridge arm in the primary switch module.

[0084] For example, the second acquisition point is the acquisition point of the voltage signal, see Figure 3 As shown, the second signal collection point is point B, which is located between the upper bridge arm switch tube P9 and the lower bridge arm switch tube P10 of the second bridge arm, and the resonant module is coupled with the second bridge arm of the primary side switch module through point B. The second voltage signal U can be collected through point B. b .

[0085] The third collection point is a common connection point of the primary coil in the resonance module and the primary inductor in the resonance module, wherein the primary coil and the primary inductor are connected in parallel.

[0086] For example, the third acquisition point is the acquisition point of the current signal, see Figure 3 As shown, the third signal collection point is point C, which is located at L r1 With the primary coil and L m The common point, or L r1 Point C, which is located after the output end and before the common node, is used to collect the first current signal in the resonant module.

[0087] It is worth noting that if point C is set between the primary inductor and point A, the collected current signal may have errors due to the primary inductor. If C is set between the excitation inductor and the primary coil, the collected current signal may have errors due to the excitation inductor. If C is set between the excitation inductor and the primary capacitor, the collected current signal may have errors due to the excitation inductor. If C is set between the primary capacitor and point B, the collected current signal may have errors due to the primary capacitor and the excitation inductor. If there is an error in the collected current signal, it is impossible to determine whether the current in the resonant circuit has a proportional relationship with the output current of the secondary switching module, and therefore it is impossible to determine whether the switching tube in the secondary switching module is faulty.

[0088] The fourth collection point is a common connection point between the third bridge arm of the secondary side switch module and the fourth bridge arm of the secondary side switch module.

[0089] In one embodiment, the fourth acquisition point is a current signal acquisition point, see Figure 3 As shown, the fourth signal collection point is point D, and point D is used to collect the output current of the secondary side switch module, that is, the second current signal.

[0090] It is worth noting that point D is set between the high-voltage output capacitor and the output load, which can avoid the influence of the high-voltage output capacitor on the output current, thereby improving the accuracy of the collected second current signal.

[0091] Optionally, the electrical signals collected by the multiple collection points include at least one of the following electrical signals:

[0092] a first voltage signal collected through the first collection point, a second voltage signal collected through the second collection point, a first current signal collected through the third collection point, and a second current signal collected through the fourth collection point.

[0093] In one embodiment, see Figure 3 As shown, the first voltage signal U can be collected through point A a , collect the second voltage signal U through point B b , collect the first current signal i through point C r1 , the second current signal i0 is collected through point D, and then the state of the switch tube in the LLC circuit can be determined based on any multiple of these point signals. For example, if only the state of the switch tube in the primary side switch module needs to be determined, the electrical signals collected at points A, B, and C can be obtained for judgment. If the state of the switch tube in the secondary side switch module needs to be determined, the electrical signals collected at points A, B, C, and D can be obtained for judgment.

[0094] Through the above method, the electrical signals collected by multiple collection points can be flexibly combined to detect multiple parts in the LLC circuit, effectively improving the detection efficiency.

[0095] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0096] The switch tubes of the LLC circuit include the switch tubes in the primary bridge arm and the switch tubes in the secondary bridge arm.

[0097] All switching tubes in the primary bridge arm and the secondary bridge arm are turned off, and the first voltage signal, the second voltage signal, and the first current signal are acquired.

[0098] In one embodiment, when the LLC circuit in the on-board charger is not in use or in standby mode, all switches in the LLC circuit are in the off state. Therefore, if the LLC circuit is checked before the on-board charger is used, the electrical signal of the set collection point can be directly collected at the beginning of the self-test. If the LLC circuit is checked while the on-board charger is in use, the first detection step can be performed, that is, after turning off all switches, the electrical signal of the set collection point can be collected.

[0099] It is worth noting that the self-test process of the LLC circuit can be performed by setting the switch tube in the primary switch module and the switch tube in the secondary switch model through the controller to perform non-synchronous analysis, that is, when any current loop is generated in the primary switch module and there is current in the resonant module, the target switch tube in the secondary switch module will automatically turn on, and the target switch tube corresponds to the switched-on switch tube in the primary switch module. For example, see Figure 3 As shown in FIG, when P7 and P10 are turned on and a current loop of U1-P7-AB-P10-U1 is generated, S1 and S4 in the secondary side switch module are automatically turned on.

[0100] By performing the first detection step at the beginning of the self-test of the LLC circuit, accidents caused by performing the detection when a switch tube in the LLC circuit fails can be avoided, thereby increasing the safety of the LLC circuit self-test process.

[0101] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0102] Wherein, when performing the above-mentioned first detection step, whether the switch tube in the LLC circuit fails can be judged according to the following situations.

[0103] Case 1: If the first voltage signal or the second voltage signal is not equal to zero, and the first current signal is not equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are in a fault state, or the upper bridge arm switch tube of the second bridge arm and the lower bridge arm switch tube of the first bridge arm are faulty.

[0104] The switch failure includes at least one of a short circuit, an open circuit, and a loss of control of the switch.

[0105] In one embodiment, see Figure 3 As shown, when P7, P8, P9 and P10 are all in the off state, if the voltage at point A and point B is not equal to 0, it means that at least two switch tubes in the primary switch module are short-circuited. If the inductor current i rl If it is not equal to 0, it means that a current loop is formed in the primary switch module, which means that the switch tubes in the same bridge arm are not short-circuited at the same time. It can be determined that P7 and P10 are short-circuited, or P8 and P9 are short-circuited.

[0106] It is worth noting that if the switch tubes in the same bridge arm of the primary switch module are short-circuited at the same time, for example, P7 and P8 are short-circuited at the same time, then the current will flow from the positive pole of U1 to P7, from P7 to P8 and then to the negative pole of U1. At this time, the current at point C is 0.

[0107] For example, when P7 and P10 are short-circuited, the current loop is from the positive pole of U1 to P7, P7 to point A, and point A to L rl , L rl To point C, C to L m , L m to C rl , C rl To point B, point B to P10, P10 to the negative terminal of U1.

[0108] Case 2: If the first voltage signal or the second voltage signal is equal to zero, and the first current signal is equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0109] In one embodiment, if the above-mentioned first detection step is performed and the electrical signals collected from points A, B, and C are all 0, it means that the initial switching tubes in the same bridge arm of the primary side switching tubes are not short-circuited at the same time, that is, P7 and P8 are not short-circuited at the same time, or P9 and P10 are not short-circuited at the same time, and then the next detection step can be performed or the self-test of the full-bridge LLC circuit can be terminated.

[0110] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0111] The upper bridge arm switch tube of the first bridge arm is turned on, and the lower bridge arm switch tube of the first bridge arm, the upper bridge arm switch tube and the lower bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal and the second current signal are collected.

[0112] In one embodiment, if the second detection step is performed after the above-mentioned first detection step is completed and no fault is found, since the switching tubes in the LLC circuit are not turned on at this time, P7 can be directly turned on. If the second detection step is performed on the LLC circuit while the on-board charger is in use, P7 can be turned on and P8 to P10 and S1 to S4 can be turned off.

[0113] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0114] Wherein, when performing the above-mentioned second detection step, it can be determined whether the switch tube in the LLC circuit fails according to the following situations.

[0115] Case 1: If the difference between the first voltage signal and the bus voltage does not exceed the preset error threshold, and the second voltage signal is equal to zero, the first current signal is not equal to zero, and the first current signal is proportional to the second current signal, it is determined that the lower arm switch tube of the second bridge arm is faulty.

[0116] In one embodiment, see Figure 3 As shown, when only P7 is turned on, if U a If the difference between U and U does not exceed the preset error threshold, it means that a current loop has been generated in the primary switch module. r1 If i0=k*i r1 (k is the transformer coil turns ratio n p / n s ), it means that current is generated in the secondary side switch module and S1 and S4 are normal. At this time, if the voltage at point B is equal to 0, it can be determined that P10 is in a short-circuit state.

[0117] It is worth noting that since the resistance of the turned-on P7 and the short-circuited P10 is very small, the voltage detected at point B is 0, and U a If the difference between the bus voltage and the voltage of the bus does not exceed the preset error threshold, it can be regarded as U a =U0.

[0118] Case 2: If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm is faulty.

[0119] In one embodiment, when only P7 is turned on, U a 、U b 、i r1 , i0 are both equal to 0, indicating that no current loop is generated in the full-bridge LLC circuit and P7 is open circuit.

[0120] Case three: if the first voltage signal is not equal to zero, and the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0121] In one embodiment, when only P7 is turned on, U a is not equal to 0, and U b 、i r1 If i and i0 are both equal to 0, it is determined that the switch tube in the LLC circuit has not failed, and the next detection step can be executed or the self-test of the full-bridge LLC circuit can be ended.

[0122] It is worth noting that if P7 is normal and turned on, and P8 is normal and turned off, then it is equivalent to the circuit formed by the input power supply and P7 and P8 being broken at P8. However, since there is a potential difference between the input and output ends of P8, the voltage at point A is not equal to 0.

[0123] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0124] The upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are turned on, and the lower bridge arm switch tube of the first bridge arm and the upper bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal and the second current signal are collected.

[0125] In one embodiment, if the third detection step is performed after the above-mentioned second detection step is performed and no fault is found, P10 can be further turned on. If the third detection step is performed on the LLC circuit while the on-board charger is in use, P7 and P10 can be turned on, and P8 to P9 and S1 to S4 can be turned off.

[0126] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0127] Wherein, when executing the third detection step, it can be determined whether the switch tube in the LLC circuit fails according to the following situations.

[0128] Case 1: If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm fails.

[0129] In one embodiment, see Figure 3 As shown, when only P7 and P10 are turned on, if i r1 and i o If it is equal to 0, it means that no current loop is formed in the resonant module and the secondary switch module, which means that there is a short circuit in the primary switch module, that is, P7 and / or P10 are in a short circuit state. However, if P7 is not short circuited, then the voltage at point A and the voltage at point B are not equal to 0. Then, when the voltage at point A and the voltage at point B are equal to 0, it can be determined that P7 is short circuited.

[0130] Case 2: If the difference between the first voltage signal and the bus voltage does not exceed the preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, it is determined that the upper arm switch tube of the third bridge arm or the lower arm switch tube of the fourth bridge arm is faulty.

[0131] In one embodiment, see Figure 3 As shown, when only P7 and P10 are turned on, if U a The difference between the bus voltage U0 and the voltage at point B is less than the preset error threshold, and the voltage at point B is 0. r1 If it is not equal to 0, it means that the current loop in the primary switch module and the resonant module is normal, that is, the current loop from the positive pole of U1 to P7, from P7 to point A, from point A to point C, from point C to point B, from point B to P10, and from P10 to the negative pole of UI is normal. Furthermore, when the current loop in the primary switch module and the resonant module is normal, the current in the resonant module should be proportional to the output current in the secondary switch module. Therefore, if i0≠k*i r1 , it means that the current loop in the secondary switch module is abnormal. Since P7 and P10 in the primary switch module and S1 and S4 in the secondary switch module are corresponding switch tubes, it can be determined that S1 or S4 is faulty.

[0132] Case three: if the difference between the first voltage signal and the bus voltage does not exceed the preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, then it is determined that the upper bridge arm switch tube of the first bridge arm, the lower bridge arm switch tube of the second bridge arm, the upper bridge arm switch tube of the third bridge arm, and the lower bridge arm switch tube of the fourth bridge arm are not faulty.

[0133] In one embodiment, see Figure 3 As shown, when only P7 and P10 are turned on, if U a The difference between the bus voltage U0 and the voltage at point B is less than the preset error threshold, and the voltage at point B is 0. r1 If it is not equal to 0, it means that the current loop in the primary switch module and the resonant module is normal, and i0=k*i r1 , indicating that the current in the resonant module is proportional to the output current in the secondary side switch module, and thus confirming that P7, P10 and S1, S4 are not faulty, and then the next detection step can be executed or the self-test of the full-bridge LLC circuit can be ended.

[0134] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0135] The upper bridge arm switch tube of the second bridge arm is turned on, and the upper bridge arm switch tube and the lower bridge arm switch tube of the first bridge arm, as well as the lower bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal, and the second current signal are collected.

[0136] In one embodiment, if the fourth detection step is performed after the above-mentioned third detection step is performed and no fault is found, P7 and P10 can be turned off and P9 can be turned on. If the fourth detection step is performed on the LLC circuit while the on-board charger is in use, P9 can be turned on and P7, P8 and P10 can be turned off.

[0137] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0138] Wherein, when executing the fourth detection step, it can be determined whether the switch tube in the LLC circuit fails according to the following situations.

[0139] Case 1: If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm is faulty.

[0140] In one embodiment, see Figure 3 As shown, when only P9 is turned on, if i r1 and i o If it is equal to 0, it means that no current loop is formed in the resonant module and the secondary switch module, U a and U b If it is equal to 0, it means that P9 is open circuit.

[0141] Case 2: If the first voltage signal is equal to zero, and the second voltage signal, the first current signal, and the second current signal are not equal to zero, it is determined that the lower bridge arm switch tube of the first bridge arm is faulty.

[0142] In one embodiment, see Figure 3 As shown, when only P9 is turned on, if i r1 and i o is not equal to 0, it means that a current loop is formed in the resonant module and the secondary switch module. If U a is equal to zero, and U b If it is not equal to 0, it means that P8 is short-circuited.

[0143] Case three: if the difference between the second voltage signal and the bus voltage is less than a preset error threshold, and the first voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0144] When it is determined by executing the fourth detection step that the switch in the LLC circuit has not failed, the next detection step may be executed or the self-test of the full-bridge LLC circuit may be terminated.

[0145] Optionally, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points includes:

[0146] The lower bridge arm switch tube of the first bridge arm, the upper bridge arm switch tube of the second bridge arm, and the upper bridge arm switch tube of the fourth bridge arm are turned on, and the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal, and the second current signal are collected.

[0147] In one embodiment, if the fifth detection step is performed after the fourth detection step is performed and no fault is found, P8 is turned on. If the fifth detection step is performed on the LLC circuit while the on-board charger is in use, P8 and P9 can be turned on, and P7 and P10 can be turned off.

[0148] The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes:

[0149] Wherein, when executing the fifth detection step, it can be determined whether the switch tube in the LLC circuit fails according to the following situations.

[0150] Case 1: If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed the preset error threshold, and the first current signal and the second current signal are equal to zero, it is determined that the lower arm switch tube of the first bridge arm is faulty.

[0151] In one embodiment, see Figure 3 As shown, when P8 and P9 are turned on and P7 and P10 are turned off, if i r1 and i0 are both equal to 0, indicating that no current loop is generated in the resonant module, which further indicates that P8 and / or P9 are in an open circuit state. If P8 and P9 are open circuited at the same time, then the voltage at point A and the voltage at point B are both equal to 0. If P9 is open circuited and P8 is normal, then the voltage at point A and the voltage at point B are not equal to 0. Therefore, in the above case, if the voltage at point A is 0 and the voltage at point B is equal to U0, it can be determined that P8 is in an abnormal state, that is, P8 is in an open circuit state.

[0152] Among them, in U b If the difference between the bus voltage and the voltage of the bus does not exceed the preset error threshold, it can be regarded as U b =U0.

[0153] Case 2: If the first voltage signal, the second voltage signal, the first voltage signal, and the second voltage signal are equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm is faulty.

[0154] Continuing to use the above embodiment for description, see Figure 3 As shown, when P8 and P9 are turned on and P7 and P10 are turned off, if the voltage at point A and the voltage at point B are both 0, and i r1 If both i and i0 are equal to 0, it means that P9 is in the open circuit state.

[0155] Case three: if the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed the preset error threshold, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, then it is determined that the lower arm switch tube of the third bridge arm or the upper arm switch tube of the fourth bridge arm is faulty.

[0156] In one embodiment, see Figure 3As shown, when P8 and P9 are turned on and P7 and P10 are turned off, if the voltage at point A is 0 and the voltage at point B is equal to U0, i r1 If it is not equal to 0, it means that a current loop is generated in the primary switch module and the resonant module. The route is from the positive pole of the input power supply to P9, from P9 to point B, from point B to the primary resonant capacitor, from the primary resonant capacitor to the first current sampling point, from the first current sampling point to point A, from point A to P8, and then from P8 to the negative pole of the input power supply. In this case, if i0≠k*i r1 , it means that the secondary switch module is abnormal. Since when P8 and P9 are turned on and there is no abnormality in the primary switch module and the resonant model, the secondary switch tubes in the secondary switch module corresponding to the current loop in the primary switch module will be turned on accordingly, that is, S2 and S3 will be turned on, and it can be determined that S2 or S3 is in an abnormal state.

[0157] Case four: if the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed the preset error threshold, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, then it is determined that the lower bridge arm switch tube of the first bridge arm, the upper bridge arm switch tube of the second bridge arm, the lower bridge arm switch tube of the third bridge arm, and the upper bridge arm switch tube of the fourth bridge arm are not faulty.

[0158] In one embodiment, see Figure 3 As shown, when P8 and P9 are turned on and P7 and P10 are turned off, if the voltage at point A is equal to 0, the voltage at point B is equal to U0, and i 0= k*i r1 , then it means that the current loops in the primary side switch module, resonant module and secondary side switch module are all in normal state, which means that there is no abnormality in the P8, P9 and S2, S3 switch tubes.

[0159] Optionally, after executing the first preset strategy to the fifth preset strategy in sequence and determining the status of each primary switch tube and the secondary switch tube, the self-test of the full-bridge LLC circuit is ended, or the next round of self-test is restarted, that is, the first preset strategy to the fifth preset strategy are repeatedly executed.

[0160] Through the above method, it is possible to accurately identify whether each switch tube in the full-bridge LLC circuit is abnormal, quickly and accurately locate the faulty switch tube, and provide a basis for the charging control of the on-board charger, thereby improving the charging efficiency and charging safety.

[0161] The present disclosure also provides an on-board charger, which is used to execute the LLC circuit detection method provided by the present disclosure.

[0162] In one embodiment, participating Figure 4As shown, the charging of the on-board charger can be controlled by the following steps.

[0163] S201 : In response to the LLC circuit soft starting and self-checking, controlling the on and off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points.

[0164] The switch tubes of the LLC circuit include the switch tubes in the primary switch module and the switch tubes in the secondary switch module.

[0165] In one embodiment, see Figure 5 As shown in the figure, after the controller receives the charging signal sent by the charging gun, it will first control the on-board charger to check the switching tube in the PFC circuit. When the self-test information of the PFC circuit indicates that there is no fault in the PFC circuit, the FPC circuit drive is enabled and the opening tube in the LLC circuit is checked.

[0166] S202: Perform a joint judgment based on the electrical signals collected by the multiple collection points to determine whether a switch in the LLC circuit fails.

[0167] S203: Determine an operating mode of the on-board charger according to a fault state of a switch in the LLC circuit.

[0168] The operating mode of the on-board charger includes at least one of full-power charging, half-power charging, and stop charging.

[0169] First, when all switches in the LLC circuit are in good working order, determine that the vehicle charger operates at full power.

[0170] Second, when at least one faulty switch exists in any one bridge of the LLC circuit and all switches in the other bridge are normal, the vehicle charger is determined to operate in a half-rated power charging mode.

[0171] Among them, P7, P10, S1 and S4 are on the same bridge, and P8, P9, S2 and S3 are on the same bridge.

[0172] For example, if P7 fails and P8, P9, S2, and S3 are all normal, the working mode of the vehicle charger is determined to be half-power charging.

[0173] Third, when at least one faulty switch tube exists in each bridge of the LLC circuit, the operation mode of the vehicle charger is determined to stop charging.

[0174] For example, if P7 and P8 fail at the same time, the working mode of the vehicle charger is determined to stop charging.

[0175] S204: Control the on-board charger according to the working mode.

[0176] In one embodiment, when the operating mode of the on-board controller is full-power charging, the LLC circuit is enabled to drive each switch tube in the LLC circuit to charge the vehicle battery at full power through the on-board charger, and return to the standby mode of the on-board charger after charging is completed.

[0177] In another embodiment, when the operating mode of the on-board controller is half-rated power charging, the LLC circuit is enabled to drive the unfaulty bridge switch tube in the LLC circuit and disable the faulty bridge switch tube, so as to charge the vehicle battery at half-rated power through the on-board charger and return to the standby mode of the on-board charger after charging is completed.

[0178] For example, if P9 fails, P7, P10, S1 and S4 in the LLC circuit can be driven, and P8, P9, S2 and S3 can be disabled, thereby charging the vehicle battery at half power through the on-board charger.

[0179] In another embodiment, when the working mode of the on-board controller is to stop charging, all switching tubes in the LLC circuit are disabled to avoid the risk of explosion of the on-board charger and improve the reliability of the on-board charger.

[0180] The present disclosure also provides a detection device 300 for an LLC circuit, see Figure 6 As shown, the LLC circuit detection device 300 includes a first control module 301 and a first determination module 302 .

[0181] The first control module 301 is configured to control the on / off of a switch in the LLC circuit in response to soft-start of the LLC circuit and self-test judgment, so as to acquire electrical signals from multiple acquisition points, where the acquisition points correspond to the primary bridge arm and / or the secondary bridge arm of the LLC circuit.

[0182] The first determination module 302 is configured to perform a joint judgment based on the electrical signals collected by the multiple collection points to determine whether a switch in the LLC circuit fails.

[0183] Optionally, the primary bridge arm includes a first bridge arm and a second bridge arm, the secondary bridge arm includes a third bridge arm and a fourth bridge arm, and the multiple collection points include at least one of the following positions:

[0184] A first collection point, wherein the first collection point corresponds to the first bridge arm.

[0185] A second collection point, wherein the second collection point corresponds to the second bridge arm.

[0186] A third collection point, the third collection point corresponds to the first bridge arm and / or the second bridge arm.

[0187] A fourth collection point, the fourth collection point corresponds to the third bridge arm and / or the fourth bridge arm.

[0188] Optionally, the electrical signals collected by the multiple collection points include at least one of the following electrical signals:

[0189] a first voltage signal collected through the first collection point, a second voltage signal collected through the second collection point, a first current signal collected through the third collection point, and a second current signal collected through the fourth collection point.

[0190] Optionally, the switch tube of the LLC circuit includes a switch tube in the primary bridge arm and a switch tube in the secondary bridge arm, and the first control module 301 is configured to:

[0191] All switching tubes in the primary bridge arm and the secondary bridge arm are turned off, and the first voltage signal, the second voltage signal, and the first current signal are acquired.

[0192] The first determining module 302 is configured to:

[0193] If the first voltage signal or the second voltage signal is not equal to zero, and the first current signal is not equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are in a fault state, or the upper bridge arm switch tube of the second bridge arm and the lower bridge arm switch tube of the first bridge arm are faulty.

[0194] If the first voltage signal or the second voltage signal is equal to zero, and the first current signal is equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0195] Optionally, the first control module 301 is configured to:

[0196] The upper bridge arm switch tube of the first bridge arm is turned on, and the lower bridge arm switch tube of the first bridge arm, the upper bridge arm switch tube and the lower bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal and the second current signal are collected.

[0197] The first determining module 302 is configured to:

[0198] If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, and the second voltage signal is equal to zero, the first current signal is not equal to zero, and the first current signal is proportional to the second current signal, it is determined that the lower arm switch tube of the second bridge arm is faulty.

[0199] If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm fails.

[0200] If the first voltage signal is not equal to zero, and the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0201] Optionally, the first control module 301 is configured to:

[0202] The upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are turned on, and the lower bridge arm switch tube of the first bridge arm and the upper bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal and the second current signal are collected.

[0203] The first determining module 302 is configured to:

[0204] If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm fails.

[0205] If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, it is determined that the upper arm switch tube of the third bridge arm or the lower arm switch tube of the fourth bridge arm is faulty.

[0206] If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, it is determined that the upper bridge arm switch tube of the first bridge arm, the lower bridge arm switch tube of the second bridge arm, the upper bridge arm switch tube of the third bridge arm, and the lower bridge arm switch tube of the fourth bridge arm are not faulty.

[0207] Optionally, the first control module 301 is configured to:

[0208] The upper bridge arm switch tube of the second bridge arm is turned on, and the upper bridge arm switch tube and the lower bridge arm switch tube of the first bridge arm, as well as the lower bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal, and the second current signal are collected.

[0209] The first determining module 302 is configured to:

[0210] If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm fails.

[0211] If the first voltage signal is equal to zero, and the second voltage signal, the first current signal, and the second current signal are not equal to zero, it is determined that the lower bridge arm switch tube of the first bridge arm fails.

[0212] If the difference between the second voltage signal and the bus voltage is less than a preset error threshold, and the first voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

[0213] Optionally, the first control module 301 is configured to:

[0214] The lower bridge arm switch tube of the first bridge arm and the upper bridge arm switch tube of the second bridge arm are turned on, and the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are turned off, and the first voltage signal, the second voltage signal, the first current signal and the second current signal are collected.

[0215] The first determining module 302 is configured to:

[0216] If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed the preset error threshold, and the first current signal and the second current signal are equal to zero, it is determined that the lower arm switch tube of the first bridge arm is faulty.

[0217] If the first voltage signal, the second voltage signal, the first voltage signal, and the second voltage signal are equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm fails.

[0218] If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, it is determined that the lower arm switch tube of the third bridge arm or the upper arm switch tube of the fourth bridge arm is faulty.

[0219] If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, it is determined that the lower bridge arm switch tube of the first bridge arm, the upper bridge arm switch tube of the second bridge arm, the lower bridge arm switch tube of the third bridge arm, and the upper bridge arm switch tube of the fourth bridge arm are not faulty.

[0220] The present disclosure also provides a control device for a vehicle charger, see Figure 7 As shown, the control device 400 of the on-board charger includes a second control module 401 , a second determination module 402 , a third determination module 403 and a third control module 404 .

[0221] The second control module 401 is configured to, in response to a detection signal for the LLC circuit, control the on and off of a switch tube in the LLC circuit to collect electrical signals from the multiple collection points, where the switch tube of the LLC circuit includes the switch tube in the primary side switch module and the switch tube in the secondary side switch module.

[0222] The second determination module 402 is configured to perform a joint judgment based on the electrical signals collected by the multiple collection points to determine whether a switch in the LLC circuit fails.

[0223] The third determining module 403 is configured to determine the operating mode of the on-board charger according to the fault state of the switch tube in the LLC circuit.

[0224] The third control module 404 is configured to control the onboard charger according to the working mode.

[0225] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0226] The present disclosure also provides a controller, comprising:

[0227] A memory having a computer program stored thereon.

[0228] A processor is used to execute the computer program in the memory to implement the above method provided by the present disclosure.

[0229] The present disclosure further provides a vehicle, which is provided with an on-board charger and a controller provided by the present disclosure, the on-board charger including an LLC circuit, and the controller coupled to multiple collection points in the LLC circuit.

[0230] The preferred embodiments of the present disclosure are described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple variations can be made to the technical solutions of the present disclosure, and these simple variations all fall within the scope of protection of the present disclosure. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner unless there is any contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0231] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A LLC circuit detection method, characterized in that: The method comprises: In response to the LLC circuit soft-starting and performing a self-test, controlling the on / off of a switch in the LLC circuit to acquire electrical signals from a plurality of acquisition points, where the acquisition points correspond to a primary bridge arm and / or a secondary bridge arm of the LLC circuit; Performing a joint judgment based on the electrical signals collected by the multiple collection points to determine whether a switch tube in the LLC circuit fails; The primary bridge arm includes a first bridge arm and a second bridge arm, the secondary bridge arm includes a third bridge arm and a fourth bridge arm, and the multiple collection points include at least one of the following positions: a first collection point, the first collection point corresponding to the first bridge arm; a second collection point, the second collection point corresponding to the second bridge arm; a third collection point, the third collection point corresponding to the first bridge arm and / or the second bridge arm; a fourth collection point, the fourth collection point corresponding to the third bridge arm and / or the fourth bridge arm; The electrical signals collected by the plurality of collection points include at least one of the following electrical signals: a first voltage signal collected through the first collection point, a second voltage signal collected through the second collection point, a first current signal collected through the third collection point, and a second current signal collected through the fourth collection point.

2. The method according to claim 1, characterized in that The switch tubes of the LLC circuit include the switch tubes in the primary bridge arm and the switch tubes in the secondary bridge arm. Controlling the on and off of the switch tubes in the LLC circuit to collect electrical signals from the plurality of collection points includes: Turning off all switching tubes in the primary bridge arm and the secondary bridge arm, and acquiring the first voltage signal, the second voltage signal, and the first current signal; The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes: If the first voltage signal or the second voltage signal is not equal to zero, and the first current signal is not equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm are in a fault state, or the upper bridge arm switch tube of the second bridge arm and the lower bridge arm switch tube of the first bridge arm are faulty; If the first voltage signal or the second voltage signal is equal to zero, and the first current signal is equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

3. The method according to claim 1, characterized in that The controlling the on and off of the switch tube in the LLC circuit to collect electrical signals from the plurality of collection points includes: Turning on the upper bridge arm switch of the first bridge arm, and turning off the lower bridge arm switch of the first bridge arm, the upper bridge arm switch and the lower bridge arm switch of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal; The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes: If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, and the second voltage signal is equal to zero, the first current signal is not equal to zero, and the first current signal is proportional to the second current signal, it is determined that the lower bridge arm switch tube of the second bridge arm is faulty; If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm is faulty; If the first voltage signal is not equal to zero, and the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

4. The method according to claim 1, wherein The controlling the on and off of the switch tube in the LLC circuit to collect electrical signals from the plurality of collection points includes: turning on the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm, and turning off the lower bridge arm switch tube of the first bridge arm and the upper bridge arm switch tube of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal; The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes: If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the upper bridge arm switch tube of the first bridge arm is faulty; If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, it is determined that the upper bridge arm switch tube of the third bridge arm or the lower bridge arm switch tube of the fourth bridge arm has a fault; If the difference between the first voltage signal and the bus voltage does not exceed a preset error threshold, the second voltage signal is equal to zero, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, it is determined that the upper bridge arm switch tube of the first bridge arm, the lower bridge arm switch tube of the second bridge arm, the upper bridge arm switch tube of the third bridge arm, and the lower bridge arm switch tube of the fourth bridge arm are not faulty.

5. The method according to claim 1, wherein The controlling the on and off of the switch tube in the LLC circuit to collect electrical signals from the plurality of collection points includes: turning on the upper bridge arm switch tube of the second bridge arm, and turning off the upper bridge arm switch tube and the lower bridge arm switch tube of the first bridge arm, as well as the lower bridge arm switch tube of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal; The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes: If the first voltage signal, the second voltage signal, the first current signal, and the second current signal are all equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm is faulty; If the first voltage signal is equal to zero, and the second voltage signal, the first current signal, and the second current signal are not equal to zero, it is determined that the lower bridge arm switch tube of the first bridge arm is faulty; If the difference between the second voltage signal and the bus voltage is less than a preset error threshold, and the first voltage signal, the first current signal, and the second current signal are equal to zero, it is determined that the switch tube in the LLC circuit is not faulty.

6. The method according to claim 1, characterized in that The controlling the on and off of the switch tube in the LLC circuit to collect electrical signals from the plurality of collection points includes: turning on the lower bridge arm switch tube of the first bridge arm and the upper bridge arm switch tube of the second bridge arm, and turning off the upper bridge arm switch tube of the first bridge arm and the lower bridge arm switch tube of the second bridge arm, and collecting the first voltage signal, the second voltage signal, the first current signal, and the second current signal; The step of jointly judging the electrical signals collected by the plurality of collection points to determine whether a switch tube in the LLC circuit fails includes: If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, and the first current signal and the second current signal are equal to zero, it is determined that the lower bridge arm switch tube of the first bridge arm is faulty; If the first voltage signal, the second voltage signal, the first voltage signal, and the second voltage signal are equal to zero, it is determined that the upper bridge arm switch tube of the second bridge arm is faulty; If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, the first current signal is not equal to zero, and the second current signal is not proportional to the first current signal, then it is determined that the lower bridge arm switch tube of the third bridge arm or the upper bridge arm switch tube of the fourth bridge arm has a fault; If the first voltage signal is equal to zero, the difference between the second voltage signal and the bus voltage does not exceed a preset error threshold, the first current signal is not equal to zero, and the second current signal is proportional to the first current signal, it is determined that the lower bridge arm switch tube of the first bridge arm, the upper bridge arm switch tube of the second bridge arm, the lower bridge arm switch tube of the third bridge arm, and the upper bridge arm switch tube of the fourth bridge arm are not faulty.

7. A vehicle-mounted charger, characterized in that: The on-board charger is used to execute the method according to any one of claims 1 to 6.

8. A vehicle, characterized in that: The vehicle is provided with the on-board charger according to claim 7.

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