Pre-detection device based on dc-dc

Abstract

The application discloses a pre-detection device and method based on DCDC and relates to the field of batteries.The pre-detection device based on DCDC comprises a first control module, a second control module, a safety threshold interval stored in the first control module, and a battery pack state parameter obtained by the first control module.If the battery pack state parameter falls into the safety threshold interval, a control instruction is sent to the second control module.The second control module is connected with a main power module, and the second control module is used for controlling the main power module according to the control instruction.The main power module is used for converting high-voltage electric energy of the battery pack into low-voltage electric energy under the control of the second control module, and the low-voltage electric energy is transmitted to a battery management module.The technical scheme provided by the embodiment of the application can improve the power-on safety of DCDC.

Description

[0001] This application is a divisional application of the invention with application number 202010165679.5, application date March 11, 2020, applicant CATL, entitled "Pre-detection device and method based on DC-DC". Technical Field

[0002] This invention relates to the field of battery power, and more particularly to a DC-DC-based pre-detection device. Background Technology

[0003] Currently, facing the challenges of energy shortages and increasingly severe environmental pollution, developing pure electric new energy vehicles is imperative and will become an important way to reduce vehicle emissions, energy consumption, and alleviate environmental pressure. Unlike traditional gasoline-powered vehicles, new energy vehicles include both high-voltage and low-voltage electrical systems. Because new energy vehicles have many high-voltage electrical components, to ensure user safety and avoid the risk of electric shock, the high-voltage and low-voltage sides are generally isolated using transformers.

[0004] As a bridge connecting high and low voltage, the Direct Current-Direct Current (DCDC) converter can convert the high-voltage DC output from the power battery pack into low-voltage DC. If the battery pack is in an abnormal state, directly powering the DCDC may affect related components in the power supply system and compromise the safety of powering the DCDC. Summary of the Invention

[0005] The DC-DC-based pre-detection device and method provided in this invention can improve the power-on safety of DC-DC converters.

[0006] On one hand, embodiments of the present invention provide a DC-DC-based pre-detection device, comprising: a first control module connected to a second control module, the first control module storing a safety threshold range, the first control module being used to acquire battery pack status parameters; if the battery pack status parameters fall within the safety threshold range, the first control module sending a control command to the second control module; a second control module connected to a main power module, the second control module being used to control the main power module according to the control command; and a main power module, the main power module being used, under the control of the second control module, to convert the high-voltage electrical energy of the battery pack into low-voltage electrical energy, and to transmit the low-voltage electrical energy to a battery management module, applied to the DC-DC-based pre-detection circuit provided in the embodiments of the present invention, comprising:

[0007] The first control module acquires the battery pack status parameters; if the battery pack status parameters fall within the safe threshold range, the first control module sends a control command to the second control module; the second control module controls the main power module according to the control command; under the control of the second control module, the main power module converts the high-voltage electrical energy of the battery pack into low-voltage electrical energy and transmits the low-voltage electrical energy to the battery management module.

[0008] On the other hand, embodiments of the present invention provide a DC-DC-based pre-detection method, applying the DC-DC-based pre-detection circuit provided in the embodiments of the present invention, including: a first control module acquiring battery pack state parameters; if the battery pack state parameters fall within a safe threshold range, the first control module sends a control command to a second control module; the second control module controls the main power module according to the control command; under the control of the second control module, the main power module converts the high-voltage power of the battery pack into low-voltage power and transmits the low-voltage power to the battery management module. According to the DC-DC-based pre-detection device and method of the present invention, before the DC-DC is powered on, if the first control module determines that the battery pack state parameters fall within a safe threshold range, it sends a control command to the second control module. After receiving the control command, the second control module controls the main power module to convert the high-voltage DC power into low-voltage DC power and uses the DC-DC power to supply power to the battery management system. The first control module can determine whether to supply power to the battery management module based on the battery pack state parameters, that is, when the battery pack state parameters exceed the safe threshold range, it does not supply power to the battery management module. Since the safety threshold range characterizes the parameter range in which the battery pack is in a safe state, the DC-DC-based pre-detection device and method provided in this embodiment of the invention can improve the power-on safety of the DC-DC converter. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the structure of a DC-DC-based pre-detection device according to an embodiment of the present invention;

[0011] Figure 2 This is a schematic diagram of the structure of a DC-DC-based pre-detection device in an embodiment of the present invention.

[0012] Figure 3 A schematic diagram of the structure of a second control module according to an embodiment of the present invention is shown;

[0013] Figure 4 A schematic diagram of an exemplary signal isolation conversion unit provided in an embodiment of the present invention is shown;

[0014] Figure 5 This is a schematic diagram of another DCDC-based pre-detection device according to an embodiment of the present invention;

[0015] Figure 6 This is a flowchart of the DCDC-based pre-detection method in an embodiment of the present invention. Detailed Implementation

[0016] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the invention.

[0017] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0018] This invention provides a method and sampling detection circuit for detecting circuit faults, applicable to scenarios where the power-on safety of a DC-DC converter is tested before power-on. The battery pack may include at least one battery module or at least one battery cell, but is not limited thereto. The battery pack can be used in electric vehicles as a power source for the motor. It can also power other electrical components in the electric vehicle, such as the air conditioner and in-vehicle media player. In this invention, by detecting whether the real-time status parameters of the battery pack are within a safe threshold range, power-on is achieved while ensuring the safety of the battery pack and the entire DC-DC power-on circuit, thus improving the power-on safety of the DC-DC converter. This invention can also be used to perform pre-detection of the BMS using the battery pack before power-on.

[0019] Figure 1This is a schematic diagram of a DC-DC-based pre-detection device according to an embodiment of the present invention. Figure 1 As shown, the DC-DC-based pre-detection device P2 in this embodiment of the invention may include a first control module P21, a second control module P22, and a main power module P23.

[0020] The first control module P21 is connected to the second control module P22. The first control module P21 stores a safety threshold range. The first control module P21 is used to acquire battery pack status parameters. Furthermore, the first control module P21 is also used to send a control command to the second control module P22 if the battery pack status parameters fall within the safety threshold range.

[0021] In some embodiments, the first control module P21 does not directly obtain the status parameters of the battery pack P1, but instead obtains the battery pack status parameters through a detection module. In this case, the DC-DC-based pre-detection device P2 may further include a detection module. This detection module can be implemented as a detection circuit.

[0022] Specifically, the detection module is connected to the battery pack P1, and the first control module P21 is connected to the detection module. The detection module is used to acquire first sampled data from the battery pack P1. The first control module P21 is also used to calculate the battery pack state parameters based on the first sampled data. The first sampled data can be a sampling voltage or a sampling circuit, etc., and is not limited thereto.

[0023] The safety threshold range refers to the parameter range within which the battery pack is in a safe state. Specifically, the safety threshold range can be a range of voltage parameters, a range of current parameters, a range of states of charge, etc., without any specific limitations.

[0024] In some embodiments, if the safety threshold range is a voltage parameter range, the upper bound of the safety threshold range is set according to the overvoltage threshold of the battery pack, and the lower bound is set according to the undervoltage threshold of the battery pack. For example, the upper bound of the safety threshold range can be the overvoltage threshold of battery pack P1, or the product of the overvoltage threshold of battery pack P1 and a first safety factor. For another example, the lower bound of the safety threshold range can be the undervoltage threshold of battery pack P1, or the product of the undervoltage threshold of battery pack P1 and a second safety factor. The first and second safety factors can be set according to the working scenario and requirements, and are not limited thereto.

[0025] Furthermore, if the acquired battery pack status parameters exceed the safety threshold range, the DC-DC converter will not be activated to supply power to the Battery Management System (BMS). Specifically, if the acquired battery pack status parameters exceed the safety threshold range, the first controller P21 will not send control commands to the second control module P22. If the second control module P22 does not receive control commands, the main power module P23 will not convert the high-voltage power supplied by the battery pack into low-voltage power, nor will it provide the low-voltage power to the battery management module. In addition, if the battery pack status parameters are determined to be higher than the upper limit of the safety threshold range, an overvoltage fault can be stored and uploaded to the vehicle controller; if the battery pack status parameters are determined to be lower than the lower limit of the safety threshold range, an undervoltage fault can be stored and uploaded to the vehicle controller.

[0026] Therefore, when the battery pack state parameters are below the lower limit of the safety threshold range, i.e., below the undervoltage threshold, the high-voltage energy of battery pack P1 will not be converted into low-voltage energy, preventing over-discharge and its impact on the lifespan of battery pack P1. When the battery pack state parameters are above the upper limit of the safety threshold range, i.e., above the overvoltage threshold, it prevents the components of the pre-detection device from being damaged by excessive voltage stress, extending their lifespan. This further ensures the safety and stability of the electric vehicle.

[0027] In some embodiments, Figure 2 This is a schematic diagram of the structure of a DC-DC-based pre-detection device according to an embodiment of the present invention. Figure 2 As shown, the first control module P21 can be implemented using a microcontroller (also known as a single-chip microcomputer).

[0028] The specific structure of the first control module P21 may include: a high-speed analog-to-digital converter (ADC) port P211, a general purpose input / output (GPIO) port P212, and a central processing unit (CPU) P213.

[0029] During the operation of the first control module P21, the ADC port P211 first acquires the first sampled data in analog signal format, converts the first sampled data from analog signal format to digital signal format, and then transmits it to the CPU P213.

[0030] Next, CPU P213 calculates the battery pack status parameters using the first sampled data. It then determines whether the calculated battery pack status parameters fall within a pre-stored safety threshold range. If they do, it sends a control command to the second control module P22 via GPIO port P212. The control signal can be an electrical signal.

[0031] In addition, the microcontroller may also include a power supply voltage interface for acquiring the first operating power. Once the microcontroller acquires the first operating power, it enters the operating state. If it fails to acquire the first operating voltage, it remains in a shutdown state. It should be noted that the terms "first" and "second" in the embodiments of this invention, and in the subsequent mention of "second operating power," are used only to distinguish the two operating power sources by name.

[0032] The second control module P22 is connected to the main power module P23. The second control module P22 is used to control the main power module P23 according to control commands. The specific implementation of the second control module P22 can be a control circuit.

[0033] In some embodiments, Figure 3 A schematic diagram of the structure of a second control module according to an embodiment of the present invention is shown. Figure 3 As shown, the second control module may include a signal isolation conversion unit P221, an auxiliary power supply unit P222, and a control unit P223.

[0034] Among them, the signal isolation conversion unit P221 is connected to the auxiliary power supply unit P222, and the auxiliary power supply unit P222 is connected to the control unit P223.

[0035] The signal isolation conversion unit P221 has high-low voltage conversion function and electrical isolation function for high-voltage side devices and low-voltage side devices. If an external low-voltage input signal is detected, the signal isolation conversion unit P221 sends a high-voltage wake-up signal to the auxiliary power supply unit P222.

[0036] Specifically, the signal isolation conversion unit P221 may include an optocoupler circuit, an isolation transformer, or other isolation chips. Furthermore, the signal isolation conversion unit P221 can also be other isolation schemes capable of converting low-voltage signals into high-voltage wake-up signals; this is not limited.

[0037] In a specific example, the signal isolation conversion unit P221 will be explained in detail using an optocoupler circuit as an example. Figure 4 A schematic diagram of an exemplary signal isolation conversion unit provided in an embodiment of the present invention is shown. Figure 4As shown, the signal isolation conversion unit can be specifically an optocoupler circuit, which includes a low-voltage signal input port A, an optical coupler (OC), and a high-voltage wake-up signal output port E.

[0038] The OC includes a light-emitting diode for converting a low-voltage signal Vin into an optical signal, and a light-receiving device for receiving the optical signal from the light-emitting diode and converting the optical signal into a high-voltage wake-up signal Vout.

[0039] In this invention, the pre-detection device can be applied to the charging process of electric vehicles. The low-voltage signal input port A can receive a 12V or 24V low-voltage signal Vin from the charging gun.

[0040] Optionally, the optocoupler circuit may also include a low-voltage filter subunit for rectifying and filtering the low-voltage signal Vin. (Continue to refer to...) Figure 4 The low-voltage filter subunit can be an RC filter subunit, specifically including a first resistor R1 and a first capacitor C1. One end of the first resistor R1 is connected to the low-voltage signal input port A, and the other end of the first resistor R1 is connected to one end of the first capacitor C1. The other end of the first capacitor C1 is connected to a first reference potential. In addition, an anti-reverse diode D1 can also be provided between the first capacitor C1 and the low-voltage signal input port A.

[0041] Optionally, the optocoupler circuit may also include a high-voltage signal filtering subunit for rectifying and filtering the high-voltage wake-up signal Vout. See further reference. Figure 4 The high-voltage signal filtering subunit includes a second resistor R2 and a second capacitor C2. One end of both the second resistor R2 and the second capacitor C2 is connected to the transmission line between OC and the high-voltage wake-up signal output port E, and the other end of both is connected to a second reference potential.

[0042] The auxiliary power supply unit P222 is used to provide a second working power to the control unit P223 in response to a high-voltage wake-up signal when it obtains the first working power. Both the first and second working power are high-voltage power.

[0043] Optionally, the auxiliary control unit P222 may include a connected flyback control subunit and a flyback transformer (i.e., a flyback transformer). The control unit P223 may include a forward control subunit and a synchronous rectification subunit. The flyback control subunit is connected to the forward control subunit, providing a second operating power source to the forward control subunit. The flyback transformer is connected to the synchronous rectification subunit, providing a second operating power source to the synchronous rectification subunit. The flyback transformer may include a first primary winding on the high-voltage side and a first secondary winding on the low-voltage side.

[0044] Specifically, after acquiring the first operating power and the high-voltage wake-up signal, the flyback control subunit can provide the forward control subunit with the second operating power and can intermittently provide the first drive signal to the drive Flyback transformer. For example, if the flyback control subunit includes a flyback controller and a first switching assembly, and the first switching assembly is located between the flyback control subunit and the Flyback transformer, the flyback controller outputs a first pulse width modulation (PWM) signal to the first switching assembly. By controlling the intermittent switching of the first switching subunit, the first drive signal is intermittently provided to the Flyback transformer. The first pulse width modulation signal includes a high-level sub-signal and a low-level sub-signal. When one of the high-level sub-signal and the low-level sub-signal is output, the first switching subunit is turned on; when the other of the high-level sub-signal and the low-level sub-signal is output, the first switching subunit is turned off. In addition, the flyback controller may be specifically a flyback control chip, and the first switching component includes at least one switch. The specific implementation of the first switching component may be a relay, a transistor, a metal oxide semiconductor (MOS) field-effect transistor or other switching device, without limitation.

[0045] During the intermittent provision of the first drive signal to the Flyback transformer, when the Flyback transformer is provided with the first drive signal, the first primary winding stores high-voltage electrical energy. When the Flyback transformer is not provided with the first drive signal, the first primary winding converts the stored high-voltage electrical energy into low-voltage electrical energy of the first secondary winding, and uses the converted low-voltage electrical energy to provide second operating power to the synchronous rectifier subunit.

[0046] In one embodiment, a first rectifier unit is further included between the Flyback transformer and the synchronous rectifier subunit for rectifying the low-voltage power coupled to the first secondary coil. Exemplarily, the first rectifier unit may include a rectifier diode. The anode of the rectifier diode is connected to the first secondary coil, and the cathode of the rectifier diode is connected to the synchronous rectifier subunit. When the first primary coil is on, the rectifier diode is in a non-conducting state due to reverse voltage; when the first primary coil is off, the rectifier diode is in a conducting state due to forward voltage. At this time, the first primary coil couples and converts the stored high-voltage power into low-voltage power for the first secondary coil, and after rectification by the rectifier diode, provides a second operating power to the synchronous rectifier module.

[0047] Furthermore, the initial operating power obtained by the auxiliary power supply unit P222 can be provided by the battery pack P1 and / or the auxiliary power supply unit P222 itself. If both the battery pack P1 and the auxiliary power supply unit P222 are powered by the auxiliary power supply unit P222, then they compete for power.

[0048] Specifically, one method for generating the first working electrical energy provided by the battery pack P1 is as follows:

[0049] A voltage divider regulator module can be used to regulate the voltage output from battery pack P1 to obtain stable initial operating power. This module can include a voltage divider unit and a voltage regulator unit. The voltage divider unit can include multiple voltage-dividing resistors, and the voltage regulator unit can include a Zener diode. By using a voltage divider regulator module, electronic components in the circuit can be protected from being damaged by high voltage.

[0050] One method for generating the first working electrical energy provided by the auxiliary power supply unit P222 itself is as follows:

[0051] If the auxiliary voltage unit P222 includes a Flyback transformer, and the Flyback transformer includes a first primary winding and a third primary winding, then a portion of the electrical energy stored in the first primary winding can be coupled to the third primary winding to generate the first operating electrical energy. Furthermore, the first operating electrical energy generated by the third primary winding can also provide operating voltage to the first control module P21.

[0052] The control unit P223 is used to control the main power module P23 according to the control command sent by the first control module P21 when the second working power is obtained. That is to say, the control unit P223 will only control the main power module P23 to perform high-low voltage conversion after simultaneously receiving the second working power and the control command.

[0053] Optionally, if the control unit P223 includes a forward control subunit and a synchronous rectification subunit, the main power module can be a forward transformer (i.e., a forward transformer). The forward transformer includes high-voltage transmission lines and low-voltage transmission lines.

[0054] The forward control subunit can control the intermittent switching of high-voltage transmission lines. For example, if the forward control subunit includes a forward controller and a second switching component, and the second switching component is located between the forward controller and the high-voltage transmission line, then the forward controller outputs a second pulse width modulation (PWM) signal to the second switching component to control the intermittent conduction of the high-voltage transmission line. Specifically, the forward controller can be a Forward control chip. The specific implementation of the second switching component and the specific method of controlling the second switching component using the second PWM signal can be found in the relevant content of the above embodiments, and will not be repeated here. Optionally, the switching states of the first and second switching components can be controlled to be mutually exclusive using a first PWM signal and a second PWM signal, respectively. Accordingly, the first and second PWM signals have the same frequency and the same or opposite voltage levels. For example, both the first and second PWM signals can be simultaneously high / low. Alternatively, when one of the first and second PWM signals is high, the other is low.

[0055] Specifically, the forward converter control subunit is used to intermittently output a second drive signal to the high-voltage transmission line of the forward converter transformer. When the high-voltage transmission line receives the second drive signal, the second primary winding converts the high-voltage electrical energy corresponding to the second drive signal into low-voltage electrical energy for the second secondary winding of the low-voltage transmission line of the forward converter transformer. Specifically, the second drive signal can be high-voltage electrical energy provided by the forward converter controller.

[0056] The synchronous rectifier subunit is connected to the low-voltage transmission line. Under the premise of obtaining the second operating power, the synchronous rectifier subunit controls the transmission of low-voltage power from the second secondary coil to the battery management module. Specifically, the synchronous rectifier subunit can use a third pulse width modulation signal to control the intermittent conduction of the low-voltage transmission line. When the low-voltage transmission line is on, the low-voltage power is transmitted to the battery management module. For example, the synchronous rectifier subunit includes a synchronous rectifier, a third switching component connected across the two ends of the second secondary coil, and a fourth switching component connected in series with the second secondary coil. The synchronous rectifier controls the switching states of the third and fourth switching components to be mutually exclusive. The synchronous rectifier can be specifically implemented as a synchronous rectifier chip. Specifically, when low-voltage power is coupled to the second secondary coil, or in other words, when the high-voltage transmission line is on, the fourth switching component is turned on, and the third switching component is turned off, so as to transmit the low-voltage power to the battery management module. When low-voltage electrical energy is not coupled to the second secondary coil, that is, when the high-voltage transmission line is disconnected, the third switch assembly is turned on and the fourth switch assembly is turned off.

[0057] The third pulse width modulation (PWM) signal can be generated by a synchronous rectifier based on the first PWM signal. Specifically, the synchronous rectifier is connected to a flyback controller, which synchronizes the first PWM signal to the synchronous rectifier. The synchronous rectifier then generates the third PWM signal based on the first PWM signal. The frequency of the first PWM signal is the same as the modulation frequency of the third PWM signal.

[0058] The main power module P23, under the control of the second control module P22, converts the high-voltage electrical energy of the battery pack P1 into low-voltage electrical energy and transmits the low-voltage electrical energy to the battery management module P3. The main power module P23 directly undertakes the task of exchanging high-voltage and low-voltage electrical energy. The main power module P23 can also achieve electrical isolation between low-voltage and high-voltage side devices. For example, the main power module P23 can be implemented as a main power circuit. The main power circuit can be an isolation transformer, optocoupler, isolation chip, or other isolation scheme capable of converting low-voltage electricity into high-voltage electricity; there are no limitations on this.

[0059] According to the DC-DC-based pre-detection device in this embodiment of the invention, before the DC-DC converter is powered on, if the first control module determines that the battery pack state parameters fall within the safe threshold range, it sends a control command to the second control module. Upon receiving the control command, the second control module controls the main power module to convert the high-voltage DC to low-voltage DC and uses this DC-DC power to supply power to the battery management system. The first control module can determine whether to supply power to the battery management module based on the battery pack state parameters; that is, when the battery pack state parameters exceed the safe threshold range, it will not supply power to the battery management module. Since the safe threshold range characterizes the parameter range in which the battery pack is in a safe state, the DC-DC-based pre-detection device and method provided in this embodiment of the invention can improve the power-on safety of the DC-DC converter.

[0060] Figure 5 This is a schematic diagram of another DCDC-based pre-detection device according to an embodiment of the present invention. Figure 5 As shown, the DC-DC-based pre-detection device includes: a microcontroller P21, a signal isolation and conversion unit P221, a Flyback control subunit P2221, a Flyback transformer T1, a Forward control subunit P2231, a synchronous rectification subunit P2232, and a Forward transformer T2.

[0061] The microcontroller P21 also includes a power input terminal VCC. The power input terminal VCC receives a first operating voltage VAux corresponding to the first operating power.

[0062] The signal isolation conversion unit P221 includes an isolation power supply P2211. The isolation power supply P2211 has an input terminal IN and an output terminal OUT. The externally input low-voltage signal Vin passes through the anti-reverse diode D1 and enters the isolation power supply P2211 from the input terminal IN. The isolation power supply P2211 converts the low-voltage signal Vin into a high-voltage wake-up signal Vout, and then transmits the high-voltage wake-up signal Vout to the Flyback control chip F1 through the output terminal OUT.

[0063] The Flyback control subunit includes a Flyback control chip F1 and a first switching component Q1. The Flyback control chip F1 includes: a power input terminal VCC, an enable control terminal Enable, a first output terminal OUT1, a second output terminal OUT2, a frequency synchronization interface SYNC, and a first overcurrent protection detection pin Isense1. Specifically, if the enable control terminal Enable receives a high-voltage wake-up signal Vout provided by the isolation power supply P2211, and the power input terminal VCC receives a first operating voltage VAux corresponding to the first operating energy, then the first output terminal OUT1 outputs second operating energy to power the Forward control chip F2. The second output terminal OUT2 is connected to the control terminal of the first switching component Q1 and outputs a first pulse width modulation signal to control the first switching component Q1. Additionally, the Flyback control chip F1 is connected to the synchronous rectifier chip F3 via the frequency synchronization interface SYNC to synchronize the first pulse width modulation signal to the synchronous rectifier chip F3. The first overcurrent protection detection pin Isense1 is connected to a second reference potential. Furthermore, the first terminal of the first switching component Q1 is connected to the first primary coil Np11, and the second terminal of the first switching component Q1 is connected to the second reference potential. For example, the control terminal of the first switching component Q1 can be the gate of a MOSFET, the first terminal of the first switching component Q1 can be the source, and the second terminal of the first switching component Q1 can be the drain.

[0064] The Flyback transformer T1 includes a first primary winding Np11, a third primary winding Np12, and a first secondary winding Ns1. One end of the first primary winding Np11 is connected to the positive terminal of the battery pack P1, and the other end is connected to the second output terminal OUT2 of the Flyback control chip F1 via a first switch submodule Q1. One end of the third primary winding Np12 is connected to a second reference potential, and the other end is the output port of the first operating voltage VAux. One end of the first secondary winding Ns1 is connected to a synchronous rectifier chip F3, and the other end is connected to the first reference potential. Optionally, during the process of providing a first drive signal to the first primary winding Np11, a portion of the electrical energy is coupled to the third primary winding Np12. The third primary winding Np12 can use this coupled energy as the first operating energy and output it from the output port of its other end. Optionally, the first secondary coil Ns1 is also connected to a filter rectifier subunit. The filter rectifier subunit includes a rectifier resistor D3 and a filter capacitor C3. The low-voltage power coupled to the first secondary coil Ns1 is rectified by the rectifier resistor D3 and filtered by the filter capacitor C3, and then supplied to the synchronous rectifier chip F3 as the second working power.

[0065] The Forward control subunit P2231 includes a Forward control chip F2 and a second switching component Q2. The Forward control chip F2 includes: a power input terminal VCC, an enable control terminal Enable, a first output terminal OUT1, a second output terminal OUT2, and a second overcurrent protection detection pin Isense2. The power input terminal VCC is connected to the first output terminal OUT1 of the Flyback control chip F1 to receive the second operating power provided by the Flyback control chip F1. The enable control terminal Enable is connected to the GPIO port of the microcontroller P21 to receive control commands sent by the microcontroller P21. Based on the received second operating power and control commands, the first output terminal OUT1 outputs a fourth pulse width modulation signal to control the start of the clamping module P26, and the second output terminal OUT2 outputs a second pulse width modulation signal to control the second switching component Q2. The second overcurrent protection detection pin Isense2 is connected to a second reference potential.

[0066] The synchronous rectification subunit P2232 includes a synchronous rectification chip F3, a third switching component Q3, and a fourth switching component Q4. The synchronous rectification chip F3 includes a power supply input terminal VCC, a frequency synchronization interface SYNC, a first output terminal OUT1, and a second output terminal OUT2. The power supply input terminal VCC is connected to the first secondary coil and is used to receive low-voltage electrical energy coupled to the first secondary coil; this low-voltage electrical energy serves as the second operating power for the synchronous rectification chip F3. The frequency synchronization interface SYNC of the synchronous rectification chip F3 is connected to the frequency synchronization interface SYNC of the Flyback control chip F1 through an isolation chip, and is used to synchronize the first pulse width modulation signal. Based on the acquisition of the second working power, the synchronous rectifier chip F3 generates a third pulse width modulation signal according to the first pulse width modulation signal. The third pulse width modulation signal can be divided into a first pulse width modulation sub-signal and a second pulse width modulation sub-signal. The first output terminal OUT1 outputs the first pulse width modulation sub-signal to control the third switching component Q3, and the second output terminal OUT2 outputs the second pulse width modulation sub-signal to control the fourth switching component Q4, so that the third switching component Q3 and the fourth switching component Q4 are in different on and off states. That is, when the third switching component Q3 is on, the fourth switching component Q4 is off, and when the third switching component Q3 is off, the fourth switching component Q4 is on.

[0067] The forward transformer T2 includes a second primary winding Np2 and a second secondary winding Ns2. One end of the second primary winding Np2 is connected to the positive terminal of the battery pack P1, and the other end of the second primary winding Np2 is connected to the second output terminal OUT2 of the Flyback control chip F1 via a second switching assembly Q2. Specifically, the control terminal of the second switching assembly Q2 is connected to the second output terminal OUT2 of the Forward control chip F2, the first terminal of the second switching assembly Q2 is connected to the other end of the second primary winding Np2, and the second terminal of the second switching assembly Q2 is connected to a second reference potential. The control terminal, the first terminal, and the second terminal of the second switching assembly Q2 can be found in the relevant descriptions of the above embodiments, and will not be repeated here.

[0068] One end of the second secondary coil Ns2 serves as the low-voltage power output port for connecting to the battery management module. The other end of the second secondary coil Ns2 is connected to the first end of the third switching assembly Q3. The second end of the third switching subunit is connected to the first reference potential. The first end of the fourth switching assembly Q4 is connected to one end of the second secondary coil Ns2, and the second end of the fourth switching assembly Q4 is connected to the second end of the third switching subunit. The control end of the third switching assembly Q3 is connected to the first output terminal OUT1 of the synchronous rectifier chip F3, and the control end of the fourth switching assembly Q4 is connected to the second output terminal OUT2 of the synchronous rectifier chip F3. The control ends, first ends, and second ends of the third switching assembly Q3 and the fourth switching assembly Q4 can be found in the relevant descriptions of the above embodiments, and will not be repeated here.

[0069] In one embodiment, continue to refer to Figure 5 The DC-DC-based pre-detection device also includes a detection module P24 located between the battery pack P1 and the microcontroller P21. The detection module P24 may specifically include multiple sampling resistors and a control switch HK. The multiple sampling resistors are connected in series, and the control switch HK is positioned between a pair of adjacent sampling resistors.

[0070] Specifically, one end of the first sampling resistor is connected to the positive terminal of battery pack P1, the other end of the first sampling resistor is connected to one end of the second sampling resistor, the other end of the second sampling resistor is connected to one end of the third sampling resistor, and so on, until the other end of the last sampling resistor is connected to the second reference potential at the negative terminal of battery pack P1. One end of the control switch HK can be connected to the other end of the penultimate sampling resistor, and the other end of the control switch HK can be connected to one end of the last sampling resistor.

[0071] Accordingly, the microcontroller P21 acquires the potential between two adjacent sampling resistors as the first sampled data. For example, the microcontroller P21 can be connected to the connection between the control switch HK and the last sampling resistor via the ADC P211. The microcontroller P21 can issue a closing command to the control switch HK. After the control switch HK closes, the ADC P211 of the microcontroller P21 detects the first sampled data, which is then converted by the CPU P213 to obtain the battery pack status parameters.

[0072] In one embodiment, the DC-DC-based pre-detection device further includes a voltage regulator module. The voltage regulator module includes a normally connected resistor unit P251 and a Zener diode ZD. The voltage regulator module is positioned between the positive terminal of the battery pack P1 and a second reference potential, used to regulate the first operating power and provide the first operating power to the Flyback control chip F1 and the microcontroller P21 using the regulated first operating power. Specifically, the normally connected resistor unit P251 includes multiple resistors connected in series. One end of the first resistor is connected to the positive terminal of the battery pack P1, and the other end of the last resistor is connected to one end of the Zener diode ZD. The other end of the Zener diode ZD is connected to the second reference potential. The first operating voltage can be obtained between the other end of the last resistor and one end of the Zener diode ZD.

[0073] In one embodiment, continue to refer to Figure 5 The DC-DC-based pre-detection device also includes a clamping module P26. The clamping module includes a fifth switch subunit Q5, a third capacitor C4, a fourth capacitor C5, and a third resistor R3. The control terminal of the fifth switch subunit Q5 is connected to the first output terminal OUT1 of the Forward control chip F2, allowing the Forward control chip F2 to output a fourth pulse width modulation signal to control the on / off state of the fifth switch subunit Q5, thereby controlling the on / off state of the clamping module P26. The first terminal of the fifth switch subunit Q5 is connected to one end of the third capacitor C4 and one end of the fourth capacitor C5, respectively. The other end of the third capacitor C4 is connected to the positive terminal of the battery pack P1 through the third resistor R3, and the other end of the fourth capacitor C5 is also connected to the positive terminal of the battery pack P1. The second terminal of the fifth switch subunit Q5 is connected to the other end of the second primary coil. The control terminal, first terminal, and second terminal of the fifth switch subunit Q5 can be found in the relevant descriptions of the above embodiments and will not be repeated here.

[0074] During the turn-off period of switch Q2, clamping module P26 resets the core of forward transformer T2 to prevent core saturation and circuit damage. Clamping module P26 absorbs the leakage inductance energy of forward transformer T2, clamping the voltage of the second switching component Q2 at a certain level and keeping it essentially constant. This avoids excessive voltage stress on the second switching component Q2, reduces its losses, and extends its service life.

[0075] In some embodiments of the present invention, the DCDC-based pre-detection device further includes:

[0076] Battery management module P3 is connected to main power module P23. Battery management module P3 is used to respond to low voltage power and control the charging line between battery pack P1 and the outside to charge battery pack P1 using the power corresponding to the low voltage signal input from the outside.

[0077] In the charging scenario where the battery pack P1 is charged using a charging gun, the signal isolation conversion unit P221 detects the low-voltage signal input from the charging gun and converts it into a high-voltage wake-up signal, waking up the auxiliary power supply unit P222. The auxiliary power supply unit P222 provides a first operating voltage to the first control module P21. After obtaining the first operating voltage, the first control module P21 determines whether the real-time voltage of the battery pack P1 is within a safe threshold range. If the real-time voltage is within the safe threshold range, the second control module P22 controls the main power module P23 to convert the high-voltage electricity of the battery pack into a low-voltage signal and sends the low-voltage signal to the BMS. Upon receiving the low-voltage signal, the BMS controls the external charging circuit of the battery pack P1 to close, and begins charging the battery pack P1 using the low-voltage power provided by the charging gun.

[0078] If the first control module P21 determines that the real-time voltage of battery pack P1 is lower than the lower limit of the safety threshold range, i.e., battery pack P1 is in an undervoltage state, it will stop executing subsequent operations to prevent over-discharge of the battery pack and its condition from being affected by over-discharge. If the first control module P21 determines that the real-time voltage of battery pack P1 is higher than the upper limit of the safety threshold range, i.e., battery pack P1 is in an overvoltage state, it will stop executing subsequent operations. This not only prevents related components in the circuit from being damaged due to excessive voltage stress, but also prevents external power supply from continuing to charge battery pack P1, thus affecting the service life of battery pack P1.

[0079] The DC-DC-based pre-detection device in the above embodiments of the present invention can be used to apply a fault detection method. Figure 6 This is a flowchart of a DC-DC-based pre-detection method according to an embodiment of the present invention. Figure 6 As shown, the DC-DC-based pre-detection method 600 may include S610 to S640.

[0080] S610, the first control module P21 acquires the battery pack status parameters. For details on the specific implementation of the battery pack status parameters, please refer to the relevant descriptions in the above embodiments of the present invention, which will not be repeated here.

[0081] S620, if the battery pack status parameters fall within the safety threshold range, the first control module P21 sends a control command to the second control module P22. For specific implementation details of the safety threshold range, the first control module P21, the second control module P22, and the control command, please refer to the relevant descriptions in the above embodiments of the present invention, which will not be repeated here.

[0082] S630, the second control module P22 controls the main power module P23 according to the control command.

[0083] S640, under the control of the second control module P22, the main power module P23 converts the high-voltage electrical energy of the battery pack P1 into low-voltage electrical energy and transmits the low-voltage electrical energy to the battery management module P3. Specific implementation details of the main power module P23 and the low-voltage electrical energy can be found in the relevant descriptions of the above embodiments of the present invention, and will not be repeated here.

[0084] In some embodiments of the present invention, the DC-DC-based pre-detection method 600 further includes: a detection module acquiring first sampling data from the battery pack P1. Accordingly, S610 specifically includes: a first control module P21 calculating battery pack state parameters based on the first sampling data. For specific implementation details of the detection module and the first sampling data, please refer to the relevant descriptions of the above embodiments of the present invention, which will not be repeated here.

[0085] In some embodiments of the present invention, if the battery pack state parameters include the voltage parameters of battery pack P1, the upper limit of the safety threshold interval is set according to the overvoltage threshold of battery pack P1, and the lower limit of the safety threshold interval is set according to the undervoltage threshold of battery pack P1.

[0086] In some embodiments of the present invention, S630 specifically includes:

[0087] If the signal isolation and conversion unit P221 of the second control module P22 detects an externally input low-voltage signal, it sends a high-voltage wake-up signal to the auxiliary power supply unit P222 of the second control module P22.

[0088] When the auxiliary power supply unit P222 obtains the first working power, it responds to the high-voltage wake-up signal and provides the second working power to the control unit P223 of the first control module P21 and the second control module P22.

[0089] When the control unit P223 obtains the second working power, it controls the main power module P23 according to the control command.

[0090] In some embodiments, the auxiliary power supply unit P222 obtains the first operating power provided by the battery pack P1 and / or the first operating power provided by the auxiliary power supply unit P222 itself.

[0091] In some embodiments of the present invention, the main power module P23 includes a forward transformer T2, which includes a high-voltage transmission line and a low-voltage transmission line. The auxiliary power supply unit P222 includes a flyback control subunit P2221 and a flyback transformer T1, which includes a first primary winding Np11 and a first secondary winding Ns1. The control unit P223 includes a forward control subunit P2231 and a synchronous rectification subunit P2232.

[0092] Accordingly, the S630 specifically includes:

[0093] The flyback control subunit P2221 provides a first drive signal to the flyback transformer T1 intermittently, and provides a second working power to the forward control subunit P2231.

[0094] When the flyback control subunit provides the first drive signal to the flyback transformer T1, the first primary coil Np11 stores high-voltage electrical energy.

[0095] When the flyback control subunit does not provide the first drive signal to the flyback transformer T1, the first primary coil Np11 converts the stored high-voltage electrical energy into low-voltage electrical energy of the first secondary coil Ns1, and uses the low-voltage electrical energy to provide the second working electrical energy for the synchronous rectifier subunit P2232.

[0096] The forward control subunit P2231 controls the intermittent switching of the high-voltage transmission line of the forward transformer T2.

[0097] When the forward control subunit provides a second drive signal to the high-voltage transmission line, the second primary coil Np2 converts the high-voltage electrical energy corresponding to the second drive signal into the low-voltage electrical energy of the second secondary coil Ns2 of the low-voltage transmission line of the forward transformer T2.

[0098] Under the premise of obtaining the second working power, the synchronous rectifier subunit P2232 controls the second secondary coil Ns2 to provide low-voltage power to the battery management module P3.

[0099] In some embodiments, the flyback control subunit P2221 includes a flyback controller F1 and a first switching component Q1, with the first switching component Q1 disposed between the flyback controller F1 and the flyback transformer T1. The forward control subunit P2231 includes a forward controller F2 and a second switching component Q2, with the second switching component Q2 disposed between the forward controller F2 and the high-voltage transmission line. The synchronous rectification subunit P2232 includes a synchronous rectifier F3, a third switching component Q3 connected across the second secondary winding Ns2, and a fourth switching component Q4 connected in series with the second secondary winding Ns2.

[0100] DC-DC-based pre-detection methods include:

[0101] The flyback controller F1 outputs a first pulse width modulation signal to the first switching assembly Q1 to intermittently provide a first drive signal to the flyback transformer T1 by controlling the intermittent switching of the first switching assembly Q1; and the flyback controller F1 synchronizes the first pulse width modulation signal to the synchronous rectifier F3.

[0102] The forward controller F2 outputs a second pulse width modulation signal to the second switching component Q2 to intermittently provide a second drive signal to the high-voltage transmission line by controlling the intermittent switching of the second switching component Q2.

[0103] Synchronous rectifier F3 generates a third pulse width modulation signal based on the first pulse width modulation signal; and synchronous rectifier F3 uses the third pulse width modulation signal to drive the third switching component Q3 and the fourth switching component Q4 to switch on and off intermittently, thereby controlling the second secondary coil Ns2 to transmit low-voltage power to the battery management module P3.

[0104] The third pulse width modulation signal controls the switching state of the third switching component Q3 and the switching state of the fourth switching component Q4, which are mutually exclusive.

[0105] In some embodiments, the flyback transformer T1 may further include a third primary winding Np12.

[0106] DCDC-based pre-detection methods also include:

[0107] When the flyback transformer T1 is turned on, the first primary coil Np11 couples part of the stored high-voltage electrical energy to the third primary coil Np12.

[0108] The third primary coil Np12 is used to provide the first operating power for the flyback control subunit F1 using a portion of the high-voltage power.

[0109] In some embodiments of the present invention, the DCDC-based pre-detection method further includes:

[0110] The battery management module P3 responds to low-voltage power and controls the charging line between the battery pack P1 and the outside to charge the battery pack P1 using the low-voltage signal input from the outside.

[0111] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The method embodiments are described relatively simply, and the relevant parts can be found in the description section of the system embodiments. This invention is not limited to the specific steps and structures described above and shown in the figures. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this invention. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0112] The functional modules in the above embodiments can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The programs or code segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information.

Claims

1. A DC-DC-based pre-detection device, characterized in that, The DC-DC-based pre-detection device includes: A first control module is connected to a second control module. The first control module stores a safety threshold range and is used to acquire battery pack status parameters. If the battery pack status parameters fall within the safety threshold range, a control command is sent to the second control module. A second control module is connected to the main power module and is used to control the main power module according to the control command. The second control module includes a control unit, which includes a synchronous rectification subunit. The main power module is used to convert the high-voltage electrical energy of the battery pack into low-voltage electrical energy under the control of the second control module, and transmit the low-voltage electrical energy to the battery management module; the main power module includes a forward transformer; The synchronous rectifier subunit is connected to the low-voltage transmission line of the forward transformer, and the synchronous rectifier subunit is used to control the second secondary coil in the low-voltage transmission line to transmit the low-voltage power to the battery management module when the second working power is obtained.

2. The DC-DC-based pre-detection device according to claim 1, characterized in that, Also includes: A clamping module is installed on the high-voltage transmission line of the forward transformer and is connected to the second control module. The clamping module is used to absorb the leakage inductance energy of the forward transformer. The second control module is also used to control the on / off state of the clamping module.

3. The DC-DC-based pre-detection device according to claim 2, characterized in that, The clamping module includes: Second resistor; A third capacitor, one end of which is connected to the positive terminal of the battery pack via a second resistor; A fourth capacitor, one end of which is connected to the positive terminal of the battery pack; The fifth switch subunit has its control terminal connected to the second control module. One end of the fifth switch subunit is connected to one end of the second primary coil in the high-voltage transmission line, and one end of the second primary coil is connected to the positive terminal of the battery pack. The other end of the fifth switch subunit is connected to the other end of the second primary coil in the high-voltage transmission line.

4. The DC-DC-based pre-detection device according to claim 1, characterized in that, The synchronous rectifier subunit is specifically used to control the intermittent conduction of the low-voltage transmission line using a third pulse width modulation signal. When the low-voltage transmission line is turned on, low-voltage power is transmitted to the battery management module.

5. The DC-DC-based pre-detection device according to claim 4, characterized in that, The synchronous rectification subunit includes: A third switching assembly is connected across the two ends of the second secondary coil; A fourth switching assembly is connected in series with the second secondary coil; A synchronous rectifier is connected to the third switching assembly and the fourth switching assembly, and the synchronous rectifier is used to control the switching state of the third switching assembly and the switching state of the fourth switching assembly to be mutually exclusive when the second working power is obtained, using the third pulse width modulation signal.

6. The DC-DC-based pre-detection device according to claim 1, characterized in that, The second control module also includes: An auxiliary power supply unit is connected to the positive terminal of the battery pack and the synchronous rectifier subunit. The auxiliary power supply unit provides the second operating power and the first pulse width modulation signal. The synchronous rectifier subunit is used to generate a third pulse width adjustment signal based on the first pulse width modulation signal when the second working power is provided.

7. The DC-DC-based pre-detection device according to claim 6, characterized in that, The auxiliary power supply unit includes: A flyback transformer is connected to the synchronous rectifier subunit. The flyback transformer includes a first primary winding and a first secondary winding. When the flyback transformer is turned on, the first primary winding is used to store high-voltage electrical energy. When the flyback transformer is turned off, the first primary winding is used to convert the stored high-voltage electrical energy into low-voltage electrical energy of the first secondary winding, and use the low-voltage electrical energy of the first secondary winding to provide a second working power to the synchronous rectifier subunit. A flyback control subunit is provided, which is connected to the flyback transformer and the synchronous rectification subunit. The flyback control subunit is used to drive the flyback transformer to switch on and off intermittently, and to provide the first pulse width adjustment signal to the synchronous rectification subunit.

8. The DC-DC-based pre-detection device according to claim 7, characterized in that, The flyback control subunit includes: A first switching assembly, connected to the first primary winding, is used to intermittently provide a first drive signal to the flyback transformer; A flyback controller is connected to the first switching assembly and the synchronous rectifier subunit. The flyback controller is used to output the first pulse width modulation signal to the first switching assembly to control the first switching assembly to switch on and off intermittently; and to output the first pulse width modulation signal to the synchronous rectifier subunit.

9. The DC-DC-based pre-detection device according to claim 7, characterized in that, The flyback transformer also includes: The third primary winding is connected to the flyback control subunit. When the flyback transformer is turned on, the first primary winding couples a portion of the stored high-voltage energy to the third primary winding. The third primary coil is used to provide the first operating power to the flyback control subunit using a portion of the high-voltage power.

10. The DC-DC-based pre-detection device according to claim 9, characterized in that, The flyback transformer is also used to provide the first operating power to the first control module.

11. The DC-DC-based pre-detection device according to claim 9, characterized in that, Also includes: A voltage regulator module is connected to the positive terminal of the battery pack and the third primary coil. The voltage regulator module is used to regulate the voltage of the first working power.

12. The DC-DC-based pre-detection device according to claim 11, characterized in that, The voltage regulator module includes: A constantly connected resistor unit is connected to the positive terminal of the battery pack; A Zener diode, one end of which is connected to the third primary coil and the constant-connected resistor unit, and the other end of which is connected to the second reference potential.

13. The DC-DC-based pre-detection device according to claim 6, characterized in that, The control unit further includes: A forward converter control subunit is provided, which is connected to the auxiliary power supply unit, the first control module, and the second primary winding of the high-voltage transmission line of the forward converter transformer. The forward converter control subunit is used to control the intermittent switching of the high-voltage transmission line according to the control commands of the first control module when a second working power source is provided. Specifically, when the high-voltage transmission line is disconnected, the second primary coil stores high-voltage electrical energy; when the high-voltage transmission line is connected, the second primary coil converts the stored high-voltage electrical energy into low-voltage electrical energy in the second secondary coil of the low-voltage transmission line of the forward transformer.

14. The DC-DC-based pre-detection device according to claim 13, characterized in that, The forward control subunit includes: A second switching assembly is connected to the high-voltage transmission line; A forward converter is connected to the first control module, the second switching assembly, and the auxiliary power supply unit. The forward converter is used to output a second pulse width modulation signal to the second switching assembly to control the intermittent conduction of the high-voltage transmission line.

15. The DC-DC-based pre-detection device according to claim 6, characterized in that, The second control module also includes: A signal isolation conversion unit is connected to an auxiliary power supply unit. The signal isolation conversion unit is used to send a high-voltage wake-up signal to the auxiliary power supply unit if a low-voltage signal is detected from an external input.

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