A direct current converter control method, a direct current converter device and a vehicle

Abstract

This invention discloses a DC-DC converter control method and a DC-DC converter device. The method includes measuring a first voltage sample value at the input terminal of a first circuit branch and measuring a first current measurement value in the first circuit branch; when the first voltage sample value exceeds a first voltage threshold range or the first current measurement value exceeds a current threshold, controlling the first circuit branch to disconnect via a first protection circuit control command; measuring a second voltage sample value at the output terminal of the DC-DC converter and measuring a second current measurement value in a second circuit branch; when the second voltage sample value exceeds a second voltage threshold range or the second current measurement value exceeds a current threshold, controlling the second circuit branch to disconnect via a second protection circuit control command.

Description

Technical Field

[0001] The present invention relates to electronic circuit technology, and more particularly to a DC-DC converter control method, a DC-DC converter device, and a vehicle. Background Technology

[0002] With the rapid development of the electric vehicle industry, the demand for energy conservation, efficiency improvement, cost reduction, and vehicle weight reduction is becoming increasingly urgent. Against this backdrop, increasing the supply voltage of low-voltage power supply systems from the traditional 12V to 48V has become an emerging development trend. This change aims to improve the overall performance and efficiency of electric vehicles.

[0003] In practical applications, some loads still retain a 12V power supply requirement due to cost and compatibility considerations. To address this, most electric vehicle electronic control units employ a step-down circuit to reduce the 48V voltage to 12V to supply the existing 12V low-voltage system. The components and loads of the 12V low-voltage system typically have a withstand voltage of up to 36V. If the overvoltage or overcurrent protection measures at the 48V input stage are inadequate, it can easily damage or even destroy the components and loads of the downstream 12V system. This situation not only affects the normal operation of the electric vehicle but may also pose a safety hazard. Summary of the Invention

[0004] This invention provides a DC-DC converter control method, a DC-DC converter device, and a vehicle, so as to achieve effective overvoltage and overcurrent protection at the 48V front-end and the 12V rear-end.

[0005] In a first aspect, embodiments of the present invention provide a DC-DC converter control method for protecting and controlling a DC-DC converter device. The DC-DC converter device includes a first circuit branch and a second circuit branch, wherein the first circuit branch is connected to the second circuit branch via a DC-DC converter, and the DC-DC converter is used for DC-DC step-down conversion between the first circuit branch and the second circuit branch. The method includes:

[0006] Measure the first voltage sample value at the input terminal of the first circuit branch, and measure the first current measurement value in the first circuit branch;

[0007] When the first voltage sample value exceeds the first voltage threshold range, or the first current measurement value exceeds the current threshold, the first circuit branch is disconnected by the first protection circuit control command.

[0008] Measure the second voltage sampling value at the output terminal of the DC-DC converter, and measure the second current measurement value in the second circuit branch;

[0009] When the second voltage sample value exceeds the second voltage threshold range, or the second current measurement value exceeds the current threshold, the second circuit branch is disconnected by the second protection circuit control command.

[0010] Optionally, it also includes measuring a first temperature sample value, and if the first temperature sample value is less than a first overheat shutdown threshold, generating the first protection circuit control command.

[0011] Optionally, it also includes measuring a second temperature sample value, and if the second temperature sample value is less than a second overheat shutdown threshold, generating a second protection circuit control command.

[0012] Optionally, if the first current measurement value is greater than the first continuous current value threshold, the first protection circuit control command is used to control the first circuit branch to disconnect after a specified time delay.

[0013] If the first current measurement value is greater than the first hard short-circuit current threshold, the first protection circuit control command is used to immediately control the first circuit branch to disconnect.

[0014] Optionally, if the second current measurement value is greater than the second continuous current value threshold, the second protection circuit control command is used to control the second circuit branch to disconnect after a specified time delay.

[0015] If the second current measurement value is greater than the second hard short-circuit current threshold, the second protection circuit control command is used to immediately control the second circuit branch to disconnect.

[0016] Secondly, embodiments of the present invention also provide a DC-DC converter device, including a first circuit branch and a second circuit branch, wherein the first circuit branch is connected to the second circuit branch through a DC-DC converter, and the DC-DC converter is used for DC-DC step-down conversion between the first circuit branch and the second circuit branch.

[0017] It also includes a first voltage sampling unit, a first current sampling unit, a second voltage sampling unit, a second current sampling unit, and a control unit;

[0018] The first voltage sampling unit is used to measure the first voltage sampling value at the input terminal of the first circuit branch, and the first current sampling unit is used to measure the first current measurement value in the first circuit branch.

[0019] The control unit is used to control the first circuit branch to disconnect via a first protection circuit control command when the first voltage sample value exceeds the first voltage threshold range or the first current measurement value exceeds the current threshold.

[0020] The second voltage sampling unit is used to measure the second voltage sampling value at the output terminal of the DC-DC converter, and the second current sampling unit is used to measure the second current measurement value in the second circuit branch;

[0021] The control unit is further configured to control the second circuit branch to disconnect via a second protection circuit control command when the second voltage sample value exceeds the second voltage threshold range, or the second current measurement value exceeds the current threshold.

[0022] Optionally, the first voltage sampling unit includes a first resistor, a second resistor, a third resistor, and a voltage sampling module;

[0023] The input terminal of the first circuit branch is grounded through a voltage divider circuit composed of the first resistor, the second resistor, and the third resistor. The sampling terminal of the voltage sampling module is connected to the connection point of the second resistor and the third resistor. The signal terminal of the voltage sampling module is connected to the control unit.

[0024] The first current sampling unit includes a first electronic fuse.

[0025] Optionally, the second voltage sampling unit includes a fourth resistor and a fifth resistor;

[0026] The voltage divider circuit formed by the fourth and fifth resistors is connected to the output terminal of the DC-DC converter, and the sampling terminal of the control unit is connected to the connection point of the fourth and fifth resistors.

[0027] The second current sampling unit includes a second electronic fuse.

[0028] Optionally, the second current sampling unit may further include a sixth resistor and a current sampling chip;

[0029] The sixth resistor is connected in series in the second circuit branch, the sampling terminal of the current sampling chip is connected in parallel across the six resistor, and the signal terminal of the current sampling chip is connected to the control unit.

[0030] Thirdly, embodiments of the present invention also provide a vehicle including any of the DC-DC converter devices described in the embodiments of the present invention.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: This embodiment proposes a DC-DC converter control method, in which the first voltage sampling value and the first current measurement value on the high-voltage side are numerically monitored, and the high-voltage side circuit branch is disconnected when the values ​​are abnormal. The output voltage sampling value and the second current measurement value of the DC-DC converter on the low-voltage side are numerically monitored, and the low-voltage side circuit branch is disconnected when the values ​​are abnormal. This can ensure that the power system can quickly cut off the power circuit under abnormal conditions, thereby ensuring the safe operation of the devices and loads in the power system. In this way, the failure rate of the low-voltage power supply system of electric vehicles can be effectively reduced, and the reliability and stability of the whole vehicle can be improved. Attached Figure Description

[0032] Figure 1 This is a flowchart of the DC-DC converter control method in the embodiment;

[0033] Figure 2 This is a block diagram of the DC-DC converter device in the embodiment;

[0034] Figure 3 This is a schematic diagram of the DC-DC converter device in the embodiment. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] Example 1

[0037] Figure 1 This is a flowchart of the DC-DC converter control method in the embodiment, for reference. Figure 1 The control methods for DC-DC converters include:

[0038] S101. Measure the first voltage sample value at the input terminal of the first circuit branch, and measure the first current measurement value in the first circuit branch.

[0039] For example, in this solution, the DC-DC converter control method is used for the protection control of a DC-DC converter device, which may include a first circuit branch and a second circuit branch.

[0040] The first circuit branch is connected to the second circuit branch via a DC-DC converter, which is used for DC-DC step-down conversion between the first and second circuit branches.

[0041] For example, in this solution, the input terminal of the first circuit branch is set to connect to a system power supply of a specified voltage level (e.g., 24-48V DC), and the output terminal of the second circuit branch is set to output power supply voltage to low-voltage electrical loads (e.g., 5-12V electrical loads).

[0042] Correspondingly, DC-DC converters are used to step down the system power supply voltage to the supply voltage required by the load (e.g., 5-12V DC).

[0043] For example, in this solution, the first voltage sample value is used to represent the voltage sample value at the input terminal of the first circuit branch, i.e., the system power input side.

[0044] The method for obtaining the first voltage sample value is not limited. For example, it can be sampled by resistor voltage division. By connecting multiple high-precision resistors in series, the voltage on the system power input side is divided proportionally. According to the voltage division formula, the sampling voltage of the voltage sampling point can be determined. This sampling voltage can be acquired by the subsequent analog-to-digital conversion unit (ADC).

[0045] Alternatively, voltage sampling can be achieved using the characteristics of a linear optocoupler. The voltage signal on the system power input side passes through the light-emitting diode terminal of the linear optocoupler, and its light intensity is proportional to the input voltage. At the receiving end of the optocoupler, the output voltage, which is proportional to the voltage on the system power input side, is obtained through photoelectric conversion and used as the first voltage sampling value.

[0046] Alternatively, based on the Hall effect, the voltage at the system power input side is converted into current through a precision resistor. The magnetic field generated by this current is detected by a Hall element, thereby generating a Hall voltage proportional to the voltage at the system power input side, which serves as the first voltage sample value.

[0047] For example, in this solution, the first current measurement value represents the current sample value that flows into the DC-DC converter through the first circuit branch;

[0048] The method of obtaining the first current measurement value is not limited. For example, a shunt can be used for current sampling. The shunt is connected in series in the first circuit branch. When the current flows through the shunt, a voltage drop will be generated across the shunt. The current value can be calculated by measuring this voltage drop and used as the first current measurement value.

[0049] Alternatively, based on the Hall effect, when current passes through a conductor placed in a magnetic field, a Hall voltage is generated in the direction perpendicular to both the current and the magnetic field. This Hall voltage is proportional to the magnetic field strength. After processing this Hall voltage, the corresponding current value can be obtained as the first current measurement value.

[0050] Alternatively, when a MOSFET is configured in the first circuit branch, the characteristics of the MOSFET itself can be used for current sampling. When the MOSFET is turned on, its drain-source voltage (VDS) has a certain relationship with the current flowing through it. By measuring VDS and combining it with the on-resistance of the MOSFET, a current value can be obtained as the first current measurement value.

[0051] S102. When the first voltage sample value exceeds the first voltage threshold range, or the first current measurement value exceeds the current threshold, the first circuit branch is disconnected by the first protection circuit control command.

[0052] For example, in this solution, the way to determine whether the first voltage sample value is abnormal is to set a fixed upper and lower voltage threshold. If the input voltage sample exceeds this range, that is, the first voltage sample value exceeds the first voltage threshold range, it is determined to be abnormal.

[0053] Alternatively, calculate the variance of the input voltage samples over a period of time. If the variance exceeds a certain set value, it indicates an abnormal voltage.

[0054] For example, in this solution, the way to determine whether the first current measurement value is abnormal is to set a fixed upper and lower threshold for the current. If the first current measurement value exceeds this range, that is, when the first current measurement value exceeds the current threshold, it is determined to be abnormal.

[0055] Alternatively, calculate the variance of the first current measurement over a period of time. If the variance exceeds a certain set value, it indicates an abnormal current.

[0056] For example, in this solution, the first circuit branch can be configured with controllable switching devices such as MOSFET switches or relays, and the first protection circuit control command can be specifically used for the on / off control of such controllable switching devices, thereby realizing the on / off control of the first circuit branch.

[0057] S103. Measure the second voltage sampling value at the output terminal of the DC-DC converter, and measure the second current measurement value in the second circuit branch.

[0058] For example, in this solution, the voltage sampling method described in S101 can be used to obtain the DC converter output voltage. The method of measuring the DC converter output voltage sampling value can be the same as or different from the method of obtaining the first voltage sampling value.

[0059] The second current measurement value can be obtained using the current sampling method described in S101. The method of measuring the second current sampling value can be the same as or different from the method of obtaining the first current sampling value.

[0060] S104. When the second voltage sampling value exceeds the second voltage threshold range, or the second current measurement value exceeds the current threshold, the second circuit branch is disconnected by the second protection circuit control command.

[0061] For example, in this solution, the method for determining whether the DC converter output voltage sampling value is abnormal can be the same as or different from the method for determining whether the first voltage sampling value is abnormal, and the method for determining whether the second current measurement value is abnormal can be the same as or different from the method for determining whether the first current measurement value is abnormal.

[0062] For example, in this solution, the second circuit branch can be configured with controllable switching devices such as MOSFET switches or relays, and the control commands of the second protection circuit can be specifically used for the on / off control of such controllable switching devices, thereby realizing the on / off control of the second circuit branch.

[0063] This embodiment proposes a DC-DC converter control method. In this method, the first voltage sampling value and the first current measurement value on the high-voltage side are numerically monitored. When the values ​​are abnormal, the high-voltage side circuit branch is disconnected. The output voltage sampling value and the second current measurement value of the DC-DC converter on the low-voltage side are numerically monitored. When the values ​​are abnormal, the low-voltage side circuit branch is disconnected. This method can ensure that the power system can quickly cut off the power circuit under abnormal conditions, thereby ensuring the safe operation of the devices and loads in the power system. In this way, it can effectively reduce the failure rate of the low-voltage power supply system of electric vehicles and improve the reliability and stability of the whole vehicle.

[0064] By detecting abnormal voltage changes on both the high-voltage and low-voltage sides, the system can quickly cut off the power supply when the voltage exceeds the withstand voltage limits of components and loads, thus preventing damage to the power system. Similarly, detecting abnormal current changes on both sides can prevent excessive current from causing temperature increases in components and wires, which can lead to serious consequences such as insulation aging, short circuits, or even fires due to prolonged overcurrent.

[0065] exist Figure 1 Based on the scheme shown, in one possible implementation, the method further includes measuring a first temperature sample value, and if the first temperature sample value is less than (or greater than) a first overheat shutdown threshold, generating a first protection circuit control command.

[0066] For example, in this solution, a first (MOS) switch is configured in the first circuit branch. When the first switch is turned on, the first circuit branch is connected, and when the first switch is turned off, the first circuit branch is disconnected.

[0067] For example, in this solution, a first protection circuit control command is set to act on the gate of the first switching transistor, thereby controlling the first switching transistor to be turned on or off.

[0068] For example, in this solution, a first temperature sampling value is set to reflect the temperature of the MOSFET, which can be expressed in the form of a voltage value. The first overheat turn-off threshold corresponds to the voltage value when the first switching transistor overheats.

[0069] One method to obtain the first temperature sampling value is to determine the MOSFET source-drain on-state voltage using the MOSFET source-drain on-resistance (RDSon) and use it as the first temperature sampling value.

[0070] Alternatively, a thermistor can be thermally coupled to a MOSFET, and a voltage divider circuit can be formed using the thermistor and a reference resistor. When the temperature changes, the resistance of the thermistor changes, which causes the output voltage of the voltage divider circuit to change. The output voltage of the voltage divider circuit is measured and used as the first temperature sampling value.

[0071] Alternatively, obtain the threshold voltage VTH of the MOSFET and use it as the first temperature sampling value.

[0072] In this scheme, the overheating of the first switching transistor is determined by comparing the first temperature sampling value with the first overheat shutdown threshold. When the first switching transistor overheats, the first circuit branch is disconnected, preventing the MOSFET from reaching the critical temperature that would cause permanent damage and ensuring that the MOSFET can continue to operate normally after the temperature returns to normal. This also prevents malfunctions in the DC-DC converter and other electronic components in the second circuit branch, which could lead to a failure of the entire power supply system. Disconnecting the overheated MOSFET prevents voltage or current fluctuations in the first circuit branch, ensuring stable operation of the power supply system.

[0073] Based on any of the aforementioned schemes, in one possible implementation scheme, a second temperature sampling value is further measured, and if the second temperature sampling value is less than a second overheat shutdown threshold, a second protection circuit control command is generated.

[0074] For example, in this solution, a second (MOS) switch is configured in the second circuit branch. When the second switch is turned on, the second circuit branch is connected, and when the second switch is turned off, the second circuit branch is disconnected.

[0075] For example, in this solution, a second protection circuit control command is set to act on the gate of the second switching transistor, thereby controlling the second switching transistor to be turned on or off.

[0076] For example, in this solution, a second temperature sampling value is set to reflect the temperature of the MOSFET, which can be expressed in the form of a voltage value. The second overheat turn-off threshold corresponds to the voltage value when the second switching transistor is overheated.

[0077] For example, in this solution, the method of obtaining the second temperature sampling value is the same as the method of obtaining the first temperature sampling value. The beneficial effect of controlling the second circuit branch to disconnect when the second switching transistor is overheated is the same as the beneficial effect of controlling the first circuit branch to disconnect when the first switching transistor is overheated. The specific details will not be repeated.

[0078] Based on any of the aforementioned schemes, in one possible implementation scheme, if the first current measurement value is greater than the first continuous current value threshold, the first protection circuit control command is used to control the first circuit branch to disconnect after a specified time delay.

[0079] If the first current measurement value is greater than the first hard short-circuit current threshold, the first protection circuit control command is used to immediately control the first circuit branch to disconnect.

[0080] For example, in this scheme, the hard short-circuit current refers to the extremely large current generated when a short-circuit fault with near-zero impedance occurs in the circuit, and the first hard short-circuit current threshold corresponds to the hard short-circuit current value of the first circuit branch.

[0081] For example, in this solution, a first continuous current value threshold is set to represent the maximum continuous current value of the first circuit branch, and a first hard short-circuit current threshold is set to be much larger than the first continuous current value threshold. When the first current measurement value is greater than the first continuous current value threshold, the first current measurement value is abnormal.

[0082] In this scheme, when the first current measurement value is between the first continuous current value threshold and the first hard short-circuit current threshold, different first current measurement values ​​correspond to different time delays;

[0083] This allows for setting an appropriate delay duration based on the specific requirements of the first circuit branch and the characteristics of the components, thereby enabling customized protection levels for the first circuit branch under different overcurrent protection requirements or application scenarios.

[0084] For example, in this solution, when the first current measurement value reaches the threshold defined under hard short circuit conditions (the first current measurement value is greater than the first hard short circuit current threshold), a very fast overcurrent protection mechanism is triggered (immediately controlling the first circuit branch to disconnect) to prevent damage to the circuit caused by large current.

[0085] Based on any of the aforementioned schemes, in one possible implementation scheme, if the second current measurement value is greater than the second continuous current value threshold, the second protection circuit control command is used to control the second circuit branch to disconnect after a specified time delay.

[0086] If the second current measurement value is greater than the second hard short-circuit current threshold, the second protection circuit control command is used to immediately control the second circuit branch to disconnect.

[0087] For example, in this scheme, the second hard short-circuit current threshold corresponds to the hard short-circuit current value of the second circuit branch, the second continuous current value threshold represents the maximum continuous current value of the second circuit branch, and the second hard short-circuit current threshold is set to be much larger than the second continuous current value threshold.

[0088] For example, in this solution, the appropriate delay duration can be set according to the specific requirements of the second circuit branch and the characteristics of the components, thereby achieving a customized protection level for the second circuit branch under different overcurrent protection requirements or application scenarios.

[0089] For example, in this scheme, when the second current measurement value reaches the threshold defined under hard short circuit conditions (the second current measurement value is greater than the second hard short circuit current threshold), a very fast overcurrent protection mechanism is triggered (immediately controlling the second circuit branch to disconnect) to prevent damage to the circuit caused by large current.

[0090] Example 2

[0091] Figure 2 This is a block diagram of the DC-DC converter device in the embodiment, for reference. Figure 2 The DC-DC converter device includes a first circuit branch and a second circuit branch. The first circuit branch is connected to the second circuit branch through a DC-DC converter 600. The second circuit branch is connected to a low-voltage load terminal. The DC-DC converter is used for DC-DC step-down conversion between the first circuit branch and the second circuit branch.

[0092] It also includes a first voltage sampling unit 100, a first current sampling unit 200, a second voltage sampling unit 300, a second current sampling unit 400, and a control unit 500;

[0093] The first voltage sampling unit 100 is used to measure the first voltage sampling value at the input terminal of the first circuit branch, and the first current sampling unit 200 is used to measure the first current measurement value in the first circuit branch.

[0094] The control unit 500 is used to control the first circuit branch to disconnect via a first protection circuit control command when the first voltage sample value exceeds a first voltage threshold range, or the first current measurement value exceeds a current threshold range; the first voltage sample value

[0095] The second voltage sampling unit 300 is used to measure the second voltage sampling value at the output terminal of the DC-DC converter, and the second current sampling unit 400 is used to measure the second current measurement value in the second circuit branch.

[0096] The control unit 500 is also used to control the second circuit branch to disconnect via a second protection circuit control command when the second voltage sampling value exceeds the second voltage threshold range or the second current measurement value exceeds the current threshold.

[0097] For example, in this solution, the first voltage sampling unit 100 and the second voltage sampling unit 300 can be configured to be designed according to any voltage sampling method described in Embodiment 1, and the first current sampling unit 200 and the second current sampling unit 400 can be configured to be designed according to any current sampling method described in Embodiment 1.

[0098] For example, in this solution, the control unit 500 can be configured to control the on / off state of the first circuit branch and the second circuit branch according to any of the control methods described in Embodiment 1.

[0099] In this solution, the DC-DC converter device can be applied to the 48V to 12V power supply system of electric vehicles. The DC-DC converter device can realize real-time monitoring and protection of 48V high voltage and 12V low voltage circuits, which can improve the overall performance and operation and maintenance efficiency of electric vehicles.

[0100] Figure 3 This is a schematic diagram of the DC-DC converter device in the embodiment, for reference. Figure 3 ,exist Figure 2 Based on the scheme shown, in one possible implementation, the first voltage sampling unit includes a first resistor R1, a second resistor R2, a third resistor R3, and a voltage sampling module U3;

[0101] The power input terminal (input terminal of the first circuit branch) HV_48V is grounded through a voltage divider circuit consisting of the first resistor R1, the second resistor R2, and the third resistor R3. The sampling terminal of the voltage sampling module U3 is connected to the connection point of the second resistor R2 and the third resistor R3. The signal terminal of the voltage sampling module U3 is connected to the control unit 500.

[0102] The first current sampling unit includes a first electronic fuse U1.

[0103] In this scheme, a first switch transistor Q1 is configured in the first circuit branch, and the control unit 500 is connected to the gate of the first switch transistor Q1 through a first electronic fuse U1;

[0104] In this scheme, the first electronic fuse U1 constitutes the HV EFUSE protection circuit. The main function of this circuit is to protect the high voltage (HV) system from damage caused by abnormal overcurrent.

[0105] HV EFUSE (First Electronic Fuse U1) is a fusible electronic fuse that automatically disconnects when it detects that the current in the high-voltage circuit exceeds the safety threshold. This disconnects the first circuit branch, preventing potential fire risks caused by circuit overload, short circuit, or other faults. This protection circuit ensures that electric vehicles can be isolated in time when problems occur in the high-voltage system, protecting the safety of occupants and the vehicle.

[0106] In this scheme, the first resistor R1, the second resistor R2, the third resistor R3 and the voltage sampling module U3 constitute the HV voltage detection circuit, which is responsible for monitoring the voltage level on the power input terminal HV_48V side in real time.

[0107] If the control unit 500 detects that the voltage on this side is too high or too low, exceeding the preset safety limit, the control unit 500 will trigger corresponding protection measures, such as activating the HV EFUSE protection circuit, to prevent damage to the high voltage system.

[0108] In this solution, the DC-DC converter 600 constitutes a 48V-12V DC-DC converter circuit. The core function of this circuit is to convert the high-voltage 48V DC power into low-voltage 12V DC power for use by the low-voltage electrical system in the vehicle.

[0109] In this solution, the control unit 500 and the DC-DC converter 700 constitute a diagnostic control circuit. The DC-DC converter 700 is used to power the control unit 500. The control unit 500 is mainly used to monitor the voltage and current of the first circuit branch and the second circuit branch in real time to ensure that the current and voltage are within a safe range. It maintains system stability through fault diagnosis and data recording. At the same time, the diagnostic control circuit is also responsible for interacting with the vehicle's communication network to realize real-time data transmission and remote diagnostic functions.

[0110] For example, in this solution, the first electronic fuse U1 is an EFUSE Controller, which can be a VNF1248F or VNF1048F. This chip is used to achieve transient overvoltage and overcurrent protection and undervoltage shutdown.

[0111] The first switching transistor Q1 is an NMOS transistor. The model can be selected according to the load current requirements. For example, if the output load power requirement is 300W, the model 100V withstand voltage IAUC90N10S5N062 can be selected.

[0112] The voltage sampling module U3 is mainly used to sample and isolate voltage signals. The voltage sampling module U3 can be designed based on a digital isolator (or optocoupler isolator), an operational amplifier, and a digital-to-analog converter module. The operational amplifier and digital-to-analog converter module are used to implement signal sampling, and the digital isolator is used to implement signal isolation transmission.

[0113] The voltage sampling module U3 can also use a voltage sampling chip. The voltage sampling chip can be an isolated operational amplifier chip AMC1311-Q1. This chip will send the collected HV_48V side voltage to the ADC acquisition interface of the control unit 500 after passing through the operational amplifier. On the other hand, it can realize voltage isolation between the 48V high side voltage and the control unit 500 to avoid damage to the latter circuit.

[0114] For example, in this solution, the normal operating voltage range of the HV_48V high-side voltage is within 75V. By configuring the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3, the voltage value after voltage division can be normally acquired by U3.

[0115] For example, in this solution, the voltage sampling value (first voltage sampling value) of the voltage sampling module U3 is determined by the following formula:

[0116] V HV_48_ADC = (R3 / (R1+R2+R3))×V HV_48V ×Gain U3

[0117] In the formula, V HV_48V The high-voltage side voltage is HV_48V, V HV_48_ADC Gain is the first voltage sample value. U3 Gain of op-amp U3 in voltage sampling module (1V / V)

[0118] In this scheme, the upper limit of the 48V system voltage is set to 70V, and the detection voltage range of the voltage sampling module U3 is 0 to 2V. Based on this condition, the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 can be designed.

[0119] For example, in this solution, the first continuous current value threshold I can be configured as follows: NOM_1 First hard short-circuit current threshold I SHORT_1 :

[0120]

[0121] In the formula, VOC_THRS_1 is the (first) current and time blocking threshold voltage, and VHSC THRS _1 is the (first) hard short-circuit threshold voltage, and Rsense_1 is the resistance value of the sampling resistor configured in the peripheral circuit of the first electronic fuse U1.

[0122] For example, in this solution, the specific values ​​of VOC_THRS_1 and VHSC_THRS_1 can be set or adjusted by configuring the relevant registers of the first electronic fuse U1.

[0123] For example, in this solution, the first continuous current value threshold I is... NOM_1 Configure its corresponding latency t NOM_1 .

[0124] For example, in this solution, when the control unit 500 determines that the first voltage sampling value is abnormal, it can control the first electronic fuse U1 to disconnect the first switching transistor Q1, thereby disconnecting the first circuit branch.

[0125] When the first current measurement value is greater than the first continuous current value threshold I NOM_1 When, the corresponding time delay t NOM_1 Then the first electronic fuse U1 is disconnected, and the first current measurement value is greater than the first hard short-circuit current threshold I. SHORT_1 At that time, the first electronic fuse U1 is disconnected.

[0126] Furthermore, in this scheme, the first temperature sampling value V can also be determined in the following way. NTC_1 :

[0127]

[0128] In the formula, V BG_1 R represents the internal reference voltage (1.2V) of the first electronic fuse U1. NTC R represents the NTC resistor in the peripheral circuit of the first electronic fuse U1. T_REF_1 This represents the reference temperature resistor in the peripheral circuit of the first electronic fuse U1.

[0129] For example, in this solution, V NTC_1 The value can be stored in a designated register of the first electronic fuse U1, and the control unit 500 can read the value.

[0130] For example, in this solution, the first overheat shutdown threshold VNTC_THRS_1 can be set or adjusted by configuring the relevant registers of the first electronic fuse U1.

[0131] For example, in this solution, overvoltage and overcurrent protection on the HV_48V side can include:

[0132] The control unit 500 determines whether the first voltage sampling value is within the range of 36 to 48V. If it exceeds the range, it controls the first electronic fuse U1 to disconnect the first switch Q1.

[0133] When the first voltage sampling value is within the range of 36 to 48V, and the first current measurement value is greater than the first continuous current value threshold I... NOM_1 At that time, the control unit 500 in the corresponding time delay t NOM_1 The first electronic fuse U1 is then disconnected.

[0134] When the first current measurement value is greater than the first hard short-circuit current threshold I SHORT_1 At that time, the first electronic fuse U1 automatically disconnects;

[0135] If the first temperature sample value is less than the first overheat shutdown threshold VNTC_THRS_1, the control unit 500 controls the first electronic fuse U1 to disconnect.

[0136] For example, in this solution, the control unit 500 communicates with the first electronic fuse U1 through the SPI interface. The control unit 500 can change the state of the first electronic fuse U1 by configuring specified parameters of the first electronic fuse U1 (such as the HWLO, HSHT and other parameter bits of VNF1048F).

[0137] For example, resetting the first electronic fuse U1, restoring the first electronic fuse U1 to the active state, or actively controlling the first electronic fuse U1 to disconnect.

[0138] refer to Figure 3 Based on any of the aforementioned schemes, in one possible implementation scheme, the second voltage sampling unit includes a fourth resistor R5 and a fifth resistor R6;

[0139] The voltage divider circuit formed by the fourth resistor R5 and the fifth resistor R6 is connected to the output terminal of the DC-DC converter, and the sampling terminal of the control unit 500 is connected to the connection point of the fourth resistor R5 and the fifth resistor R6.

[0140] The second current sampling unit includes a second electronic fuse U2.

[0141] In this scheme, a second switch Q2 is configured in the second circuit branch, and the control unit 500 is connected to the gate of the second switch Q2 through the first electronic fuse U2.

[0142] In this scheme, the second electronic fuse U2 constitutes the LV EFUSE protection circuit. The second electronic fuse U2 is an EFUSE Controller, and the model can be VNF1248F or VNF1048F, to realize transient overvoltage and overcurrent protection and undervoltage shutdown.

[0143] The second switching transistor Q2 is an NMOS transistor. The model can be selected according to the load current requirements. For example, if the output load power requirement is 300W, the model IAUC120N04S6L009 with a withstand voltage of 60V can be selected.

[0144] The fourth resistor R5 and the fifth resistor R6 constitute the LV voltage detection circuit. R5 and R6 are connected in series to divide the LV_12V low-voltage side voltage and output it to the ADC interface of the control unit 500 for voltage acquisition.

[0145] For example, in this solution, the LV EFUSE protection circuit is similar to the HV EFUSE protection circuit. The LV EFUSE protection circuit is used to protect the low voltage (LV) system. It monitors the current in the low voltage circuit to ensure that the circuit can be quickly disconnected in the event of an overcurrent, thereby protecting the components in the low voltage system from damage and avoiding potential electrical fire risks.

[0146] The LV voltage detection circuit monitors the voltage level of the low-voltage system, ensuring that all low-voltage loads operate under stable voltage. Through real-time monitoring, the control unit 500 can respond quickly to voltage anomalies, taking necessary measures such as adjusting the power output or activating protection circuits to maintain system stability and safety.

[0147] For example, in this solution, the DC-DC converter output voltage sampling value V is configured. LV_12V_ADC Determined by the following formula:

[0148] V LV_12V_ADC = (R6 / (R5+R6))×V LV_12V

[0149] In the formula, V LV_12V This indicates the low-voltage side voltage of LV_12V.

[0150] For example, in this solution, the second continuous current value threshold I can be configured as follows: NOM_2 Second hard short-circuit current threshold I SHORT_2 :

[0151]

[0152] In the formula, VOC_THRS_2 is the (second) current and time blocking threshold voltage, VHSC_THRS_2 is the (second) hard short-circuit threshold voltage, and Rsense_2 is the resistance value of the sampling resistor configured in the peripheral circuit of the second electronic fuse U2.

[0153] For example, in this solution, the specific values ​​of VOC_THRS_2 and VHSC_THRS_2 can be set or adjusted by configuring the relevant registers of the second electronic fuse U2.

[0154] For example, in this solution, the first continuous current value threshold I is... NOM_2 Configure its corresponding latency t NOM_2 .

[0155] For example, in this solution, when the control unit 500 determines that the first voltage sampling value is abnormal, it can control the second electronic fuse U2 to disconnect the second switch Q2, thereby disconnecting the second circuit branch.

[0156] When the second current measurement value is greater than the second continuous current value threshold I NOM_2 When, the corresponding time delay t NOM_2 Then the second electronic fuse U2 is disconnected, and the second current measurement value is greater than the second hard short-circuit current threshold I. SHORT_2 At that time, the second electronic fuse U2 is disconnected.

[0157] Furthermore, in this scheme, the second temperature sampling value V can also be determined in the following way. NTC_2 :

[0158]

[0159] In the formula, V BG_2 This indicates the internal reference voltage (1.2V) of the second electronic fuse U2, R. NTC_2 R represents the NTC resistor in the peripheral circuit of the second electronic fuse U2. T_REF_2 This represents the reference temperature resistor in the peripheral circuit of the second electronic fuse U2.

[0160] For example, in this solution, V NTC_2 The value can be stored in a designated register of the second electronic fuse U2, and the control unit 500 can read the value.

[0161] For example, in this solution, the second overheat shutdown threshold VNTC_THRS_2 can be set or adjusted by configuring the relevant registers of the second electronic fuse U2.

[0162] For example, in this solution, overvoltage and overcurrent protection for the LV_12V side can include:

[0163] The control unit 500 determines whether the first voltage sample value is within the range of 9 to 16V. If it exceeds this range, it controls the second electronic fuse U2 to disconnect the second switch Q2.

[0164] When the first voltage sampling value is within the range of 9 to 16V, and the second current measurement value is greater than the second continuous current value threshold I... NOM_2 At that time, the control unit 500 in the corresponding time delay t NOM_2 The second electronic fuse U2 is then disconnected.

[0165] When the second current measurement value is greater than the second hard short-circuit current threshold I SHORT_2 At that time, the second electronic fuse U2 automatically disconnects;

[0166] If the second temperature sampling value is less than the second overheat shutdown threshold VNTC_THRS_2, the control unit 500 controls the second electronic fuse U2 to disconnect.

[0167] refer to Figure 3 Based on any of the aforementioned schemes, in one possible implementation scheme, the second current sampling unit further includes a sixth resistor R6 and a current sampling chip U4;

[0168] The sixth resistor R6 is connected in series in the second circuit branch, the sampling terminal of the current sampling chip U4 is connected in parallel across the six resistor R6, and the signal terminal of the current sampling chip U4 is connected to the control unit 500.

[0169] For example, in this solution, the sixth resistor R6 and the current sampling chip U4 constitute the LV current detection circuit. The current sampling chip U4 can be a current sensing operational amplifier chip TSC1021B. This chip converts the current detected on the LV_12V low voltage side into a voltage signal, amplifies it, and outputs it to the ADC interface of the control unit 500 for acquisition.

[0170] R4 is the current sensing and sampling resistor. The model can be selected according to the load current requirements. For example, if the output load power requirement is 300W, a 0.003Ω / 3W sampling resistor can be selected.

[0171] For example, in this solution, the control unit 500 is configured to determine the current sampling value according to the following formula:

[0172] V LV_12V_CURRENT_ADC =R4×I LV_12V ×Gain U4

[0173] In the formula, V LV_12V_CURRENT_ADC I is the current sampling value. LV_12V For the LV_12V low-voltage side current, Gain U4 The gain of the current sampling chip U4 op-amp is 50V / V.

[0174] For example, in this solution, the LV current detection circuit monitors the current in the low-voltage system. By continuously measuring the current, the circuit can promptly detect abnormal current patterns in the system, such as overcurrent or short circuit. This information can be used to diagnose system faults, optimize the power management system, and ensure the normal operation of low-voltage electrical equipment.

[0175] For example, in this solution, the overvoltage and overcurrent protection for the LV_12V side can include:

[0176] The control unit 500 determines whether the first voltage sample value is within the range of 9 to 16V. If it exceeds this range, it controls the second electronic fuse U2 to disconnect the second switch Q2.

[0177] When the first voltage sampling value is within the range of 9 to 16V, determine the current sampling value V. LV_12V_CURRENT_ADC If the threshold value is exceeded, the second switch Q2 will be disconnected by controlling the second electronic fuse U2.

[0178] At the current sampling value V LV_12V_CURRENT_ADC Within the set threshold range, when the second current measurement value is greater than the second continuous current value threshold I NOM_2 At that time, the control unit 500 in the corresponding time delay t NOM_2 The second electronic fuse U2 is then disconnected.

[0179] When the second current measurement value is greater than the second hard short-circuit current threshold I SHORT_2 At that time, the second electronic fuse U2 automatically disconnects;

[0180] If the second temperature sampling value is less than the second overheat shutdown threshold VNTC_THRS_2, the control unit 500 controls the second electronic fuse U2 to disconnect.

[0181] For example, in this solution, the peripheral circuits of the first electronic fuse U1, the second electronic fuse U2, the voltage sampling module U3, and the current sampling chip U4 can be designed according to the typical peripheral circuits provided in the manual of the corresponding chip model. The specific details will not be described in detail.

[0182] refer to Figure 3 In this embodiment, the DC-DC converter device includes an overcurrent and overvoltage protection circuit based on a fusible electronic fuse. The HV and LV EFUSE protection circuits effectively prevent the risk of controller motherboard burnout caused by overcurrent. At the same time, the HV and LV voltage detection circuits and the LV current detection circuit monitor the voltage and current in real time, ensuring that the system operates within the normal operating range.

[0183] Example 3

[0184] This embodiment proposes a vehicle that includes any of the DC-DC converter devices described in Embodiment 2. The implementation method and beneficial effects of the DC-DC converter are the same as the corresponding content described in Embodiment 2, and the specific details will not be described in detail.

[0185] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A DC converter control method for protection control of a DC converter device, the DC converter device comprising a first circuit branch and a second circuit branch, the first circuit branch being connected to the second circuit branch by a DC converter for DC step-down conversion between the first circuit branch and the second circuit branch, characterized in that, include: Measure the first voltage sample value at the input terminal of the first circuit branch, and measure the first current measurement value in the first circuit branch; When the first voltage sample value exceeds the first voltage threshold range, or the first current measurement value exceeds the current threshold, the first circuit branch is disconnected by the first protection circuit control command. Measure the second voltage sampling value at the output terminal of the DC-DC converter, and measure the second current measurement value in the second circuit branch; When the second voltage sample value exceeds the second voltage threshold range, or the second current measurement value exceeds the current threshold, the second circuit branch is disconnected by the second protection circuit control command.

2. The dc-to-dc converter control method of claim 1, wherein, It also includes measuring the first temperature sampling value of the switching transistor in the first circuit branch, and generating the first protection circuit control command if the first temperature sampling value is less than the first overheat shutdown threshold.

3. The DC converter control method of claim 1, wherein, It also includes measuring the second temperature sampling value of the switching transistor in the second circuit branch, and generating the second protection circuit control command if the second temperature sampling value is less than the second overheat shutdown threshold.

4. The dc-to-dc converter control method of any one of claims 1 to 3, wherein, If the first current measurement value is greater than the first continuous current value threshold, the first protection circuit control command is used to control the first circuit branch to disconnect after a specified time delay. If the first current measurement value is greater than the first hard short-circuit current threshold, the first protection circuit control command is used to immediately control the first circuit branch to disconnect.

5. The dc-to-dc converter control method of any one of claims 1 to 3, wherein, If the second current measurement value is greater than the second continuous current value threshold, the second protection circuit control command is used to control the second circuit branch to disconnect after a specified time delay; If the second current measurement value is greater than the second hard short-circuit current threshold, the second protection circuit control command is used to immediately control the second circuit branch to disconnect.

6. A DC converter arrangement characterized in that It includes a first circuit branch and a second circuit branch. The first circuit branch is connected to the second circuit branch through a DC-DC converter. The DC-DC converter is used for DC-DC step-down conversion between the first circuit branch and the second circuit branch. It also includes a first voltage sampling unit, a first current sampling unit, a second voltage sampling unit, a second current sampling unit, and a control unit; The first voltage sampling unit is used to measure the first voltage sampling value at the input terminal of the first circuit branch, and the first current sampling unit is used to measure the first current measurement value in the first circuit branch. The control unit is used to control the first circuit branch to disconnect via a first protection circuit control command when the first voltage sample value exceeds the first voltage threshold range or the first current measurement value exceeds the current threshold. First voltage sample value The second voltage sampling unit is used to measure the second voltage sampling value at the output terminal of the DC-DC converter, and the second current sampling unit is used to measure the second current measurement value in the second circuit branch; The control unit is further configured to control the second circuit branch to disconnect via a second protection circuit control command when the second voltage sample value exceeds the second voltage threshold range, or the second current measurement value exceeds the current threshold.

7. The dc-to-dc converter device of claim 6, wherein, The first voltage sampling unit includes a first resistor, a second resistor, a third resistor, and a voltage sampling module; The input terminal of the first circuit branch is grounded through a voltage divider circuit composed of the first resistor, the second resistor, and the third resistor. The sampling terminal of the voltage sampling module is connected to the connection point of the second resistor and the third resistor. The signal terminal of the voltage sampling module is connected to the control unit. The first current sampling unit includes a first electronic fuse.

8. The dc-to-dc converter device of any one of claims 6 or 7, wherein, The second voltage sampling unit includes a fourth resistor and a fifth resistor; The voltage divider circuit formed by the fourth and fifth resistors is connected to the output terminal of the DC-DC converter, and the sampling terminal of the control unit is connected to the connection point of the fourth and fifth resistors. The second current sampling unit includes a second electronic fuse.

9. The dc-to-dc converter device of claim 8, wherein, The second current sampling unit also includes a sixth resistor and a current sampling chip; The sixth resistor is connected in series in the second circuit branch, the sampling terminal of the current sampling chip is connected in parallel across the six resistor, and the signal terminal of the current sampling chip is connected to the control unit.

10. A vehicle characterized by comprising: Includes the DC-DC converter device according to any one of claims 6 to 9.

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