CN113394831B

CN113394831B - DCDC-based pre-detection device and method

Info

Publication number: CN113394831B
Application number: CN202010165679.5A
Authority: CN
Inventors: 王连松; 蔡福鹏; 侯贻真; 刘昌鑑; 叶伏明; 颜利丹
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2024-01-23
Anticipated expiration: 2040-03-11
Also published as: CN113394831A; CN117748659A

Abstract

The invention discloses a pre-detection device and method based on DCDC, and relates to the field of batteries. The DCDC-based pre-detection device comprises: the first control module is connected with the second control module, the first control module stores a safety threshold interval, and the first control module is used for acquiring state parameters of the battery pack; 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 the main power module and is used for controlling the main power module according to the control instruction; and the main power module is used for converting the high-voltage electric energy of the battery pack into low-voltage electric energy under the control of the second control module and transmitting the low-voltage electric energy to the battery management module. The technical scheme provided by the embodiment of the invention can improve the power-on safety of DCDC.

Description

DCDC-based pre-detection device and method

Technical Field

The invention relates to the field of battery power, in particular to a pre-detection device and method based on DCDC.

Background

At present, in the current situation of energy shortage and increasingly serious environmental pollution, the development of new energy automobiles with pure electric power is imperative, and the new energy automobiles become an important way for reducing automobile exhaust emission, energy consumption and relieving environmental pressure. Unlike conventional fuel automobiles, new energy automobiles include a high-voltage electric system and a low-voltage electric system. Because there are many high-voltage electric appliances on the new energy automobile, in order to guarantee user's safety, avoid taking place personnel's risk of electrocuting, generally keep apart high-pressure side and low-pressure side through the transformer.

And as a bridge for connecting high voltage and low voltage, direct Current-Direct Current (DCDC) conversion between high voltage and low voltage can convert high voltage dc output by the power battery pack into low voltage dc. If the state of the battery pack is abnormal, the DCDC is directly electrified, and the related devices of the power supply system can be influenced, so that the electrification safety of the DCDC is influenced.

Disclosure of Invention

The pre-detection device and the pre-detection method based on the DCDC can improve the power-on safety of the DCDC.

In one aspect, an embodiment of the present invention provides a DCDC-based pre-detection device, including: the first control module is connected with the second control module, the first control module stores a safety threshold interval, and the first control module is used for acquiring state parameters of the battery pack; 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 the main power module and 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 transmitting the low-voltage electric energy to the battery management module, and is applied to the DCDC-based pre-detection circuit provided by the embodiment of the invention, and comprises the following components:

The first control module acquires battery pack state parameters; if the battery pack state parameter falls into the safety threshold interval, the first control module sends a control instruction to the second control module; the second control module controls the main power module according to the control instruction; under the control of the second control module, the main power module converts high-voltage electric energy of the battery pack into low-voltage electric energy and transmits the low-voltage electric energy to the battery management module.

On the other hand, the embodiment of the invention provides a pre-detection method based on DCDC, and the pre-detection circuit based on DCDC provided by the embodiment of the invention comprises the following steps: the first control module acquires battery pack state parameters; if the battery pack state parameter falls into the safety threshold interval, the first control module sends a control instruction to the second control module; the second control module controls the main power module according to the control instruction; under the control of the second control module, the main power module converts high-voltage electric energy of the battery pack into low-voltage electric energy and transmits the low-voltage electric energy to the battery management module. According to the DCDC-based pre-detection device and the DCDC-based pre-detection method, before the DCDC is powered on, if the first control module determines that the state parameters of the battery pack fall into the safety threshold interval, a control instruction is sent to the second control module. And after receiving the control instruction, the second control module controls the main power module to convert the direct-current high-voltage power into direct-current low-voltage power, and supplies power for the battery management system by using the direct-current power. The first control module may determine whether to power the battery management module according to the battery pack status parameter, that is, when the battery pack status parameter exceeds the safety threshold interval, not to power the battery management module. The safety threshold interval represents the parameter interval of the battery pack in the safety state, and the DCDC-based pre-detection device and method provided by the embodiment of the invention can improve the power-on safety of the DCDC.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings that are needed to be used in the embodiments of the present invention will be briefly described, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a pre-detection device based on DCDC according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a DCDC-based pre-detection device in an example of an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a second control module according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating an exemplary signal isolation conversion unit according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of another DCDC-based pre-detection device according to an embodiment of the present invention;

fig. 6 is a flowchart of a DCDC-based pre-detection method according to an embodiment of the present invention.

Detailed Description

Features and exemplary embodiments of various aspects of the present invention will be described in detail below, and in order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely configured to illustrate the invention and are not configured to limit the invention. It will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by showing examples of the invention.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

The embodiment of the invention provides a circuit fault detection method and a sampling detection circuit, which can be applied to a specific scene of detecting the power-on safety of DCDC before power-on. The battery pack may include at least one battery module or at least one battery unit, which is not limited herein. The battery pack can be applied to an electric automobile and used as a power source of the electric automobile to supply power for the motor. The battery pack can also supply power for other electric devices in the electric automobile, such as an in-car air conditioner, an in-car player and the like. In the embodiment of the invention, by detecting whether the real-time state parameter of the battery pack is in the safety threshold interval, the power-on safety of the DCDC is improved on the premise that the battery pack and the whole DCDC power-on circuit are ensured to have safety. The embodiment of the invention can be used for pre-detecting the BMS before powering on by using the battery pack.

Fig. 1 is a schematic structural diagram of a DCDC-based pre-detection device according to an embodiment of the present invention. As shown in fig. 1, the DCDC-based pre-detection device P2 in the embodiment of the present invention may include a first control module P21, a second control module P22, and a main power module P23.

The first control module P21 is connected to the second control module P22. The first control module P21 stores a safety threshold interval. The first control module P21 is configured to obtain a battery pack status parameter. And, the first control module P21 is further configured to send a control instruction to the second control module P22 if the battery pack status parameter falls within the safety threshold interval.

In some embodiments, the first control module P21 does not obtain its state parameters directly from the battery pack P1, but obtains the battery pack state parameters through the detection module. At this time, the DCDC-based pre-detection device P2 may further include a detection module. Wherein the detection module may be implemented as a detection circuit.

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 for acquiring first sampling data from the battery pack P1. The first control module P21 is further configured to calculate a battery pack status parameter according to the first sampling data. The first sampling data may be a sampling voltage or a sampling circuit, etc., which is not limited.

The safety threshold interval represents a parameter interval in which the battery pack is in a safe state. Specifically, the safety threshold interval may be a voltage parameter interval, a current parameter interval, a state of charge interval, or the like, which is not particularly limited.

In some embodiments, if the safety threshold interval is a voltage parameter interval, an upper bound of the safety threshold interval is set according to an over-voltage threshold of the battery pack, and a lower bound of the safety threshold interval is set according to an under-voltage threshold of the battery pack. As an example, the upper bound of the safety threshold interval may be the overpressure threshold of the battery pack P1, or the product of the overpressure threshold of the battery pack P1 and the first safety factor. As another example, the lower bound of the safety threshold interval may be the under-voltage threshold of the battery pack P1, or the product of the under-voltage threshold of the battery pack P1 and the second safety factor. The first safety coefficient and the second safety coefficient can be set according to a working scene and a working requirement, and the method is not limited.

In addition, if the acquired battery pack state parameter exceeds the safety threshold interval, the DCDC is not started to supply power to the battery management module (Battery Management System, BMS). Specifically, if the obtained battery pack state parameter exceeds the safety threshold interval, the first controller P21 does not send a control command to the second control module P22. If the second control module P22 does not receive the control command, the main power module P23 does not convert the high voltage power provided by the battery pack into low voltage power, and provides the low voltage power to the battery management module. In addition, if the state parameter of the battery pack is judged to be higher than the upper limit value of the safety threshold interval, the overvoltage fault can be stored and uploaded to the whole vehicle controller; if the state parameter of the battery pack is judged to be lower than the lower limit value of the safety threshold interval, the under-voltage fault can be stored and uploaded to the whole vehicle controller.

Therefore, when the battery pack state parameter is lower than the lower limit value of the safety threshold interval, that is, lower than the undervoltage threshold of the battery pack, the high-voltage electric energy of the battery pack P1 is not converted into the low-voltage electric energy, so that the overdischarge of the battery pack can be prevented, and the service life of the battery pack P1 is influenced due to the overdischarge. When the state parameter of the battery pack is higher than the upper limit value of the safety threshold interval, namely higher than the overvoltage threshold of the battery pack, the related devices of the pre-detection device can be prevented from being damaged due to overlarge voltage stress, and the service life of the related devices is prolonged. Thereby further ensuring the safety and stability of the electric automobile.

In some embodiments, fig. 2 is a schematic structural diagram of a DCDC-based pre-detection device in an example of an embodiment of the present invention. As shown in fig. 2, the specific implementation of the first control module P21 may be a microcontroller (also referred to as a single-chip microcomputer).

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 (General Purpose Input Output, GPIO) port P212, and a central processing unit (central processing unit, CPU) P213.

In the working process of the first control module P21, first, the ADC port P211 collects first sampling data in an analog signal format, converts the first sampling data from an analog signal format signal to a digital signal format, and then transmits the first sampling data to the CPU P213.

Next, the CPU P213 calculates a battery pack state parameter using the first sampling data. And judging whether the calculated battery pack state parameter falls into a pre-stored safety threshold interval, and if so, sending a control instruction to the second control module P22 through the GPIO port P212. The control signal may be an electrical signal.

The microcontroller may further comprise a supply voltage interface for deriving the first operating power. After the microcontroller acquires the first working electric energy, the microcontroller enters a working state. And if the first working voltage is not obtained, the working voltage is in a shutdown state. It should be noted that, the "first" and "second" in the first working electric energy and the second working electric energy appearing in the subsequent process in the embodiments of the present invention are only used to distinguish the two working electric energies from each other by name.

The second control module P22 is connected to the main power module P23. The second control module P22 is configured to control the main power module P23 according to a control instruction. The specific implementation of the second control module P22 may be a control circuit.

In some embodiments, fig. 3 is a schematic structural diagram of a second control module according to an embodiment of the present invention. As shown in fig. 3, the second control module may include a signal isolation conversion unit P221, an auxiliary power unit P222, and a control unit P223.

The signal isolation conversion unit P221 is connected to the auxiliary power unit P222, and the auxiliary power unit P222 is connected to the control unit P223.

The signal isolation conversion unit P221 has a high-low voltage conversion function and a function of electrically isolating a high-voltage side device from a low-voltage side device. The signal isolation conversion unit P221 is configured to send a high-voltage wake-up signal to the auxiliary power unit P222 if an externally input low-voltage signal is detected.

Specifically, the signal isolation conversion unit P221 may include an optocoupler circuit, an isolation transformer, other isolation chips, and the like. In addition, the signal isolation conversion unit P221 may be another isolation scheme capable of converting a low voltage signal into a high voltage wake-up signal, which is not limited.

In a specific example, the signal isolation conversion unit P221 is specifically explained by taking an optocoupler circuit as an example. Fig. 4 is a schematic diagram illustrating a structure of an exemplary signal isolation conversion unit according to an embodiment of the present invention. As shown in fig. 4, the signal isolation conversion unit may be specifically an optical coupling circuit, where the optical coupling circuit includes a low voltage signal input port a, an Optical Coupler (OC), and a high voltage wake-up signal output port E.

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

The pre-detection device provided by the embodiment of the invention can be applied to the charging process of the electric automobile. The low voltage signal input port a may receive a low voltage signal Vin of 12V or 24V inputted by the charging gun.

Optionally, the optocoupler circuit may further include a low-voltage filtering subunit rectifying and filtering the low-voltage signal Vin. With continued reference to fig. 4, the low-voltage filter subunit may be an RC filter subunit, specifically including a first resistor R1 and a first capacitor C1. One end of a first resistor R1 is connected with the low-voltage signal input port A, the other end of the first resistor R1 is connected with one end of a first capacitor C1, and the other end of the first capacitor C1 is connected with a first reference potential bit. In addition, an anti-reflection diode D1 may be further provided between the first capacitor C1 and the low voltage signal input port a.

Optionally, the optocoupler circuit may further comprise a high voltage signal filtering subunit rectifying and filtering the high voltage wake-up signal Vout. With continued reference to fig. 4, the high voltage signal filtering subunit includes a second resistor R2 and a second capacitor C2. One ends of the second resistor R2 and the second capacitor C2 are connected to a transmission line between the OC and the high-voltage wake-up signal output port E, and the other ends of the second resistor R2 and the second capacitor C2 are connected with a second reference potential bit.

The auxiliary power supply unit P222 is configured to provide the control unit P223 with the second operating power in response to the high voltage wake-up signal in case of acquiring the first operating power. Wherein, the first working electric energy and the second working electric energy are both high-voltage electric energy.

Optionally, the auxiliary control unit P222 may include a Flyback transformer (i.e., flyback transformer) and a Flyback control subunit connected. The control unit P223 may include a forward control subunit and a synchronous rectification subunit. The flyback control subunit is connected with the forward control subunit and provides second working electric energy for the forward control subunit. The Flyback transformer is connected with the synchronous rectifying subunit and provides second working electric energy for the synchronous rectifying 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.

Specifically, after acquiring the first operating power and the high voltage wake-up signal, the Flyback control subunit may provide the second operating power to the Flyback control subunit and may provide the first drive signal to the drive Flyback transformer at intervals. For example, if the Flyback control subunit includes a Flyback controller and a first switching assembly, the first switching assembly is disposed between the Flyback control subunit and the Flyback transformer. The Flyback controller outputs a first pulse width modulation (Pulse width modulation, PWM) signal to the first switching assembly to intermittently provide a first drive signal to the Flyback transformer by controlling the first switching subunit to intermittently turn on and off. The first pulse width modulation signal comprises a high level sub-signal and a low level sub-signal, the first switch sub-unit is turned on when one of the high level sub-signal and the low level sub-signal is output, and the first switch sub-unit is turned off when the other of the high level sub-signal and the low level sub-signal is output. In addition, the Flyback controller may be specifically a Flyback control chip, the first switch component includes at least one switch, and the specific implementation of the first switch component may be a relay, a triode, a metal oxide semiconductor (Metal Oxide Semiconductor, MOS) field-effect transistor, or other switching device, which is not limited thereto.

The first primary winding stores high voltage power when the Flyback transformer is supplied with the first drive signal during the intermittent supply of the first drive signal. When the Flyback transformer is not provided with the first driving signal, the first primary coil converts the stored high-voltage electric energy into low-voltage electric energy of the first secondary coil, and the second working electric energy is provided for the synchronous rectifying subunit by utilizing the converted low-voltage electric energy.

In one embodiment, a first rectifying unit is further included between the Flyback transformer and the synchronous rectifying subunit, and is configured to rectify the piezoelectric energy coupled to the first secondary winding. The first rectifying unit may include a rectifying diode. The anode of the rectifying diode is connected with the first secondary coil, and the cathode of the rectifying diode is connected with the synchronous rectifying subunit. When the first primary coil is conducted, the rectifier diode is in a non-conducting state due to the fact that reverse voltage is born; when the first primary coil is disconnected, the rectifier diode is in a conducting state due to the fact that forward voltage is born, at the moment, the first primary coil couples and converts stored high-voltage electric energy into low-voltage electric energy of the first secondary coil, and the second working electric energy is provided for the synchronous rectifier module after the rectifier diode is utilized for rectification.

Further, the first operating power acquired by the auxiliary power unit P222 may be provided by the battery pack P1 and/or the auxiliary power unit P222 itself. If the battery pack P1 and the auxiliary power unit P222 supply power to the auxiliary power unit P222 themselves, they compete for power supply.

Specifically, one way of generating the first operating power provided by the battery pack P1 is as follows:

the voltage output by the battery pack P1 can be divided and stabilized by the voltage dividing and stabilizing module, so as to obtain stable first working electric energy. The voltage dividing and stabilizing module can comprise a voltage dividing unit and a voltage stabilizing unit. The voltage dividing unit may include a plurality of voltage dividing resistors, and the voltage stabilizing unit may include a voltage stabilizing diode. By arranging the voltage dividing and stabilizing module, electronic components in the circuit can be protected from being broken down by high voltage.

One way of generating the first operating power provided by the auxiliary power unit P222 itself is as follows:

if the auxiliary voltage unit P222 includes a Flyback transformer, the Flyback transformer includes a first primary winding and a third primary winding. A portion of the electrical energy stored by the first primary winding may be coupled to the third primary winding to generate a first operating electrical energy. In addition, the third primary winding generates the first operating power to provide the operating voltage for the first control module P21.

The control unit P223 is configured to control the main power module P23 according to a control instruction sent by the first control module P21 when the second operating power is acquired. That is, the control unit P223 must receive the second operating power and the control command at the same time, and then control the main power module P23 to perform the high-low voltage conversion.

Alternatively, if the control unit P223 includes a Forward control subunit and a synchronous rectifier subunit, the main power module may be a Forward transformer (i.e., a Forward transformer). Forward transformers include high voltage transmission lines and low voltage transmission lines.

The forward control subunit can control the intermittent on-off of the high-voltage transmission line. For example, if the forward control subunit includes a forward controller and a second switch assembly, the second switch assembly is disposed between the forward controller and the high voltage power transmission line. The forward controller is configured to output a second pwm signal to the second switching assembly to control the intermittent conduction of the high voltage transmission line. The Forward controller may be specifically a Forward control chip, and the specific implementation manner of the second switch component and the specific manner of controlling the second switch component by using the second pwm signal may be referred to the relevant content of the above embodiment, which is not described herein again. Alternatively, the switching state of the first switching component and the switching state of the second switching component may be controlled to be mutually exclusive by using the first pulse width modulation signal and the second pulse width modulation signal, respectively. Accordingly, the first pulse width modulation signal and the second pulse width modulation signal have the same frequency, the same level or opposite levels. For example, both the first pulse width modulated signal and the second pulse width modulated signal are high/low at the same time. Alternatively, when one of the first and second pwm signals is at a high level, the other is at a low level.

Specifically, the forward control subunit is used for outputting the second driving signal to the high-voltage transmission line of the forward transformer at intervals. When the high-voltage transmission line receives a second driving signal, the second primary coil converts high-voltage electric energy corresponding to the second driving signal into low-voltage electric energy of a second secondary coil of the low-voltage transmission line of the forward transformer. In particular, the second drive signal may be high voltage power provided by a forward controller.

The synchronous rectifier subunit is connected with the low-voltage power transmission line and is used for controlling the low-voltage power transmission of the second secondary coil to the battery management module on the premise of acquiring the second working power. The synchronous rectifier subunit can control the low-voltage transmission line to conduct at intervals by using a third pulse width modulation signal, and when the low-voltage transmission line is conducted, the synchronous rectifier subunit transmits the low-voltage energy to the battery management module. The synchronous rectifier subunit includes a synchronous rectifier, a third switching component connected across the second secondary winding, and a fourth switching component connected in series with the second secondary winding. The synchronous rectifier controls the switching state of the third switching component and the switching state of the fourth switching component to be mutually exclusive. The synchronous rectifier may be embodied as a synchronous rectification chip. Specifically, when the low-voltage power is coupled to the second secondary winding, it can also be said that the high-voltage power transmission line is turned on, the fourth switching component is controlled to be turned on, and the third switching component is turned off, so as to transmit the low-voltage power to the battery management module. When the low-voltage power is not coupled to the second secondary winding, that is, the high-voltage power transmission line is disconnected, the third switch component is controlled to be turned on, and the fourth switch component is controlled to be turned off.

The third pulse width modulated signal may be generated by the synchronous rectifier based on the first pulse width modulated signal. Specifically, the synchronous rectifier is connected with a flyback controller, and the flyback controller synchronizes the first pulse width modulation signal to the synchronous rectifier, and the synchronous rectifier generates a third pulse width modulation signal based on the first pulse width modulation signal. The frequency of the first pulse width modulation signal is the same as the modulation frequency of the third pulse width signal.

The main power module P23 is configured to convert high-voltage electric energy of the battery pack P1 into low-voltage electric energy under the control of the second control module P22, and transmit the low-voltage electric energy to the battery management module P3. The main power module P23 characterizes a module which directly takes on the task of exchanging high-voltage electrical energy with low-voltage electrical energy. The main power module P23 may also achieve electrical isolation between the low-side device and the high-side device. By way of example, a specific implementation of the main power module P23 may be a main power circuit. The main power circuit may be an isolation transformer, an optocoupler, an isolation chip, or other isolation scheme capable of converting high voltage power to high voltage power, without limitation.

According to the DCDC-based pre-detection device in the embodiment of the invention, before the DCDC is powered on, if the first control module determines that the state parameter of the battery pack falls into the safety threshold interval, a control instruction is sent to the second control module. And after receiving the control instruction, the second control module controls the main power module to convert the direct-current high-voltage power into direct-current low-voltage power, and supplies power for the battery management system by using the direct-current power. The first control module may determine whether to power the battery management module according to the battery pack status parameter, that is, when the battery pack status parameter exceeds the safety threshold interval, not to power the battery management module. The safety threshold interval represents the parameter interval of the battery pack in the safety state, and the DCDC-based pre-detection device and method provided by the embodiment of the invention can improve the power-on safety of the DCDC.

Fig. 5 is a schematic structural diagram of another DCDC-based pre-detection device according to an embodiment of the present invention. As shown in fig. 5, the DCDC-based pre-detection device includes: the microcontroller P21, the signal isolation conversion unit P221, the Flyback control subunit P2221, the Flyback transformer T1, the Forward control subunit P2231, the synchronous rectifier subunit P2232 and the Forward transformer T2.

The microcontroller P21 also includes a power supply input VCC. The power supply input VCC receives a first operating voltage VAux corresponding to the first operating power.

The signal isolation conversion unit P221 includes an isolated power source P2211. The isolated power supply P2211 includes an input terminal IN and an output terminal OUT. After the low-voltage signal Vin input from the outside passes through the anti-reflection diode D1, the low-voltage signal Vin enters the isolation power P2211 from the input end IN, and the isolation power P2211 converts the low-voltage signal Vin into the 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 end OUT.

The Flyback control subunit includes a Flyback control chip F1 and a first switching assembly Q1. The Flyback control chip F1 includes: the power supply 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. If the Enable control terminal Enable receives the high-voltage wake-up signal Vout provided by the isolation power P2211, the power supply input terminal VCC receives a first working voltage VAux corresponding to the first working electric energy, the first output terminal OUT1 outputs a second working electric energy for supplying power to the Forward control chip F2, the second output terminal OUT2 is connected with the control terminal of the first switch component Q1, and the second output terminal OUT2 outputs a first pulse width modulation signal for controlling the first switch component Q1. In addition, the Flyback control chip F1 is connected to the synchronous rectification chip F3 through the frequency synchronization interface SYNC, and is configured to synchronize the first pwm signal to the synchronous rectification chip F3. The first overcurrent protection sense pin Isense1 is connected to the second reference potential bit. In addition, a first end of the first switching element Q1 is connected to the first primary winding Np11, and a second end of the first switching element Q1 is connected to the second reference potential. For example, the control end of the first switch component Q1 may be a gate of the MOS transistor, the first end of the first switch component Q1 may be a source, and the second end of the first switch component Q1 may be a drain.

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 electrode of the battery pack P1, and the other end of the first primary winding Np11 is connected to the second output terminal OUT2 of the Flyback control chip F1 through the first switch sub-module Q1. One end of the third primary winding Np12 is connected to the second reference potential bit, and the other end of the third primary winding Np12 is an output port of the first working voltage VAux. One end of the first secondary winding Ns1 is connected to the synchronous rectification chip F3, and the other end of the first secondary winding Ns1 is connected to the first reference potential. Alternatively, in the process of supplying the first driving signal to the first primary winding Np11, a part of the power may be coupled to the third primary winding Np12, and the third primary winding Np12 may output the part of the power coupled thereto as the first operation power from the output port of the other end of the third primary winding Np 12. Optionally, the first secondary winding Ns1 is also connected to a filter rectifier subunit. The filtering rectifier subunit includes a rectifying resistor D3 and a filtering capacitor C3, and the low-voltage power coupled to the first secondary winding Ns1 is rectified by the rectifying resistor D3, and the filtered power is provided as second working power to the synchronous rectifying chip F3 after being filtered by the filtering capacitor C3.

The Forward control subunit P2231 includes a Forward control chip F2 and a second switching component Q2.Forward control chip F2 includes: the power supply 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 supply input terminal VCC is connected to the first output terminal OUT1 of the Flyback control chip F1, and is configured to receive the second operating power provided by the Flyback control chip F1. The enabling control end Enable is connected with a GPIO port of the microcontroller P21 and is used for receiving a control instruction sent by the micro-control P21. On the basis of receiving the second operating power and the control command, the first output terminal OUT1 outputs a fourth pwm signal for controlling the start of the clamp module P26, and the second output terminal OUT2 outputs a second pwm signal for controlling the second switching element Q2. The second overcurrent protection detection pin Isense2 is connected to a second reference potential bit.

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 VCC is connected to the first secondary winding for receiving low-voltage power coupled to the first secondary winding, and the low-voltage power is used as the second working power of the synchronous rectification chip F3. The frequency synchronization interface SYNC of the synchronous rectification chip F3 is connected with the frequency synchronization interface SYNC of the Flyback control chip F1 through an isolation chip, and is used for synchronizing the first pulse width modulation signal. On the basis of obtaining the second working electric energy, the synchronous rectification 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 end OUT1 outputs the first pulse width modulation sub-signal to control the third switch component Q3, the second output end OUT2 outputs the second pulse width modulation sub-signal to control the fourth switch component Q4, so that the third switch component Q3 and the fourth switch component Q4 are in different on-off states, namely, when the third switch component Q3 is turned on, the fourth switch component Q4 is turned off, and when the third switch component Q3 is turned off, the fourth switch component Q4 is turned on.

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 electrode 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 through the second switching assembly Q2. Specifically, the control end of the second switch component Q2 is connected to the second output end OUT2 of the Forward control chip F2, the first end of the second switch component Q2 is connected to the other end of the second primary winding Np2, and the second end of the second switch component Q2 is connected to the second reference potential. The control end, the first end and the second end of the second switch component Q2 can be referred to the related description of the above embodiments, and will not be described herein again.

One end of the second sub-winding Ns2 serves as an output port of low-voltage power for connecting to the battery management module. The other end of the second secondary winding Ns2 is connected to a first end of the third switching element Q3, a second end of the third switching sub-unit is connected to the first reference potential, a first end of the fourth switching element Q4 is connected to one end of the second secondary winding Ns2, and a second end of the fourth switching element Q4 is connected to a second end of the third switching sub-unit. The control end of the third switch component Q3 is connected to the first output end OUT1 of the synchronous rectification chip F3, and the control end of the fourth switch component Q4 is connected to the second output end OUT2 of the synchronous rectification chip F3. The control terminal, the first terminal and the second terminal of the third switch component Q3 and the fourth switch component Q4 can be referred to the related description of the above embodiments, and are not repeated herein.

In one embodiment, with continued reference to fig. 5, the DCDC-based pre-detection device further includes a detection module P24 disposed between the battery pack P1 and the microcontroller P21. The detection module P24 may specifically include a plurality of sampling resistors and a control switch HK. The sampling resistors are sequentially connected in series, and the control switch HK is arranged between a certain pair of adjacent sampling resistors.

Specifically, one end of the first sampling resistor is connected with the positive electrode of the battery pack P1, the other end of the first sampling resistor is connected with one end of the second sampling resistor, … …, and the other end of the last sampling resistor is connected with the negative electrode voltage equalizing second reference potential of the battery pack P1. One end of the control switch HK may be connected to the other end of the last sampling resistor, and the other end of the control switch HK may be connected to one end of the last sampling resistor.

Accordingly, the microcontroller P21 collects the potential between some adjacent sampling resistors as the first sampling data. For example, the microcontroller P21 may be connected to the connection between the control switch HK and the last sampling resistor through the ADC P211. The microcontroller P21 may issue a closing command to the control switch HK, after the control switch HK is closed, the ADC P211 of the microcontroller P21 detects the first sampling data, and the battery pack state parameter is obtained after conversion by the CPU P213.

In one embodiment, the DCDC-based pre-detection device further includes a voltage stabilizing module. The voltage stabilizing module comprises a normally-hung resistor unit P251 and a voltage stabilizing diode ZD, and is arranged between the positive electrode of the battery pack P1 and the second reference potential position and used for stabilizing the first working electric energy and providing the first working electric energy for the Flyback control chip F1 and the microcontroller P21 by utilizing the stabilized first working electric energy. Specifically, the conventional resistor unit P251 includes a plurality of resistors connected in series, one end of the first resistor is connected to the positive electrode of the battery pack P1, the other end of the last resistor is connected to one end of the zener diode ZD, and the other end of the zener diode ZD is connected to the second reference potential. Wherein a first operating voltage may be obtained between the other end of the last resistor and one end of the zener diode ZD.

In one embodiment, with continued reference to fig. 5, the DCDC-based pre-detection device further includes a clamp module P26. The clamping module comprises a fifth switch subunit Q5, a third capacitor C4, a fourth capacitor C5 and a second capacitor R2. The control end of the fifth switch subunit Q5 is connected to the first output end OUT1 of the Forward control chip F2, so that the Forward control chip F2 outputs a fourth pwm signal to control the on/off of the fifth switch subunit Q5, thereby realizing the on/off control of the clamp module P26. The first end of the fifth switch subunit Q5 is connected with 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 with the positive electrode of the battery pack P1 through the second capacitor R2, and the other end of the fourth capacitor C5 is connected with the positive electrode of the battery pack P1. A second terminal of the fifth switching sub-unit Q5 is connected to the other terminal of the second primary winding. The control terminal, the first terminal and the second terminal of the fifth switch subunit Q5 can be referred to the related description of the above embodiments, and will not be described herein.

The clamping module P26 resets the core of the forward transformer T2 during the off period of the switching tube Q2, so as to prevent the core of the forward transformer T2 from being saturated and damaging the circuit. The clamping module P26 can absorb leakage inductance energy of the forward transformer T2, clamp the voltage of the second switch component Q2 at a certain level and basically keep unchanged, so that larger voltage stress on the second switch component Q2 is avoided, loss of the second switch component Q2 is reduced, and the service life of the transformer is prolonged.

In some embodiments of the invention, the DCDC-based pre-detection means further comprises:

the battery management module P3, the battery management module P3 is connected to the main power module P23, and the battery management module P3 is configured to respond to low-voltage power, and control the charging circuit between the battery pack P1 and the outside to be turned on, so as to charge the battery pack P1 with power corresponding to the low-voltage signal input from the outside.

In a charging scenario in which the battery pack P1 is charged by using the charging gun, the signal isolation conversion unit P221 converts a low-voltage signal input by the charging gun into a high-voltage wake-up signal after detecting the signal, wakes up the auxiliary power supply unit P222, and the auxiliary power supply unit P222 provides the first control module P21 with the first operating voltage. After the first operating voltage is obtained, the first control module P21 determines whether the real-time voltage of the battery pack P1 is within the safety threshold interval. If the real-time voltage is within the safety threshold interval, the second control module P22 controls the main power module P23 to convert the high voltage of the battery pack into a low voltage signal, and sends the low voltage signal to the BMS. The BMS receives the low voltage power signal, controls the external charging circuit of the battery pack P1 to be closed, and starts to charge the battery pack P1 with the low voltage power supplied from the charging gun.

If the first control module P21 determines that the real-time voltage of the battery pack P1 is lower than the lower limit value of the safety threshold interval, that is, the battery pack P1 is in an under-voltage state, the subsequent operation is stopped, the battery pack is prevented from overdischarging, and the battery pack state is prevented from being affected by overdischarging. If the first control module P21 determines that the real-time voltage of the battery pack P1 is higher than the upper limit value of the safety threshold interval, that is, the battery pack P1 is in an overvoltage state, the subsequent operation is stopped, which not only can prevent related devices in the circuit from being damaged due to the overlarge voltage stress, but also can prevent the service life of the battery pack P1 from being affected by the continuous charging of the battery pack P1 by the external power supply.

The DCDC-based pre-detection device in the above embodiment of the present invention may apply a fault detection method. Fig. 6 is a flowchart of a DCDC-based pre-detection method according to an embodiment of the present invention. As shown in fig. 6, the DCDC-based pre-detection method 600 may include S610 to S640.

S610, the first control module P21 acquires the battery pack status parameter. The specific implementation of the battery pack status parameter may be referred to the related description of the above embodiments of the present invention, and will not be described herein.

S620, if the battery pack status parameter falls within the safety threshold interval, the first control module P21 sends a control command to the second control module P22. The specific implementation of the safety threshold interval, the first control module P21, the second control module P22, and the control command may be referred to the related description of the above embodiment of the present invention, and will not be repeated herein.

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

S640, under the control of the second control module P22, the main power module P23 converts the high-voltage power of the battery pack P1 into low-voltage power and transmits the low-voltage power to the battery management module P3. The specific implementation of the main power module P23 and the low-voltage power can be referred to the related description of the above embodiments of the present invention, and will not be repeated here.

In some embodiments of the present invention, the DCDC-based pre-detection method 600 further includes: the detection module acquires first sampling data from the battery pack P1. Accordingly, S610 specifically includes: the first control module P21 calculates a battery pack state parameter from the first sampling data. The specific implementation manners of the detection module and the first sampling data may refer to the related descriptions of the foregoing embodiments of the present invention, and are not repeated herein.

In some embodiments of the present invention, if the battery pack status parameter includes a voltage parameter of the battery pack P1, an upper limit value of the safety threshold interval is set according to an overvoltage threshold of the battery pack P1, and a lower limit value of the safety threshold interval is set according to an undervoltage threshold of the battery pack P1.

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

If the signal isolation conversion unit P221 of the second control module P22 detects the low voltage signal input from the outside, it sends a high voltage wake-up signal to the auxiliary power unit P222 of the second control module P22.

The auxiliary power unit P222 provides the second operating power to the control units P223 of the first and second control modules P21 and P22 in response to the high voltage wake-up signal when the first operating power is obtained.

The control unit P223 controls the main power module P23 according to the control instruction in the case of acquiring the second operating power.

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

In some embodiments of the present invention, if the main power module P23 includes a forward transformer T2, the forward transformer T2 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, the flyback transformer T1 including a first primary winding Np11 and a first secondary winding Ns1. The control unit P223 includes a forward control subunit P2231 and a synchronous rectifier subunit P2232.

Accordingly, S630 specifically includes:

The flyback control subunit P2221 provides the flyback transformer T1 with the first drive signal intermittently, and provides the forward control subunit P2231 with the second operating power.

The first primary winding Np11 stores high voltage power while the flyback control subunit provides the flyback transformer T1 with a first driving signal.

When the flyback control subunit does not provide the flyback transformer T1 with the first driving signal, the first primary winding Np11 converts the stored high-voltage electric energy into the low-voltage electric energy of the first secondary winding Ns1, and provides the synchronous rectifier subunit P2232 with the second working electric energy by using the low-voltage electric energy.

The forward control subunit P2231 controls the intermittent on-off of the high-voltage transmission line of the forward transformer T2.

When the forward control subunit provides a second driving signal for the high-voltage transmission line, the second primary winding Np2 converts high-voltage electric energy corresponding to the second driving signal into low-voltage electric energy of the second secondary winding Ns2 of the low-voltage transmission line of the forward transformer T2.

The synchronous rectifier subunit P2232 controls the second secondary winding Ns2 to provide the battery management module P3 with the second operating power.

In some embodiments, if the flyback control subunit P2221 includes a flyback controller F1 and a first switching component Q1, the first switching component Q1 is disposed between the flyback controller F1 and the flyback transformer T1. The forward control subunit P2231 includes a forward controller F2 and a second switch assembly Q2, where the second switch assembly Q2 is disposed between the forward controller F2 and the high-voltage power transmission line. The synchronous rectifier 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 Ns 2.

The DCDC-based pre-detection method comprises the following steps:

the flyback controller F1 outputs a first pulse width modulation signal to the first switch assembly Q1 so as to intermittently provide a first driving signal for the flyback transformer T1 by controlling the intermittent on-off of the first switch assembly Q1; and, the flyback controller F1 synchronizes the first pulse width modulated signal to the synchronous rectifier F3.

The forward controller F2 outputs a second pulse width modulation signal to the second switching component Q2 to intermittently supply a second driving signal to the high-voltage transmission line by controlling the intermittent on-off of the second switching component Q2.

The synchronous rectifier F3 generates a third pwm signal based on the first pwm signal; and the synchronous rectifier F3 drives the third switching component Q3 and the fourth switching component Q4 to be turned on and off at intervals by using the third pwm signal to control the second secondary winding Ns2 to transmit the low-voltage energy to the battery management module P3.

The third pwm signal controls the switching state of the third switching component Q3 and the switching state of the fourth switching component Q4 to be mutually exclusive.

In some embodiments, the flyback transformer T1 further includes a third primary winding Np12.

The pre-detection method based on DCDC further comprises the following steps:

When the flyback transformer T1 is on, the first primary winding Np11 couples a portion of the stored high voltage electrical energy to the third primary winding Np12.

The third primary winding Np12 is configured to provide the flyback control subunit F1 with the first operating power by using a portion of the high-voltage power.

In some embodiments of the present invention, the DCDC-based pre-detection method further comprises:

the battery management module P3 controls the charge line between the battery pack P1 and the outside to be turned on in response to the low voltage power, so as to charge the battery pack P1 with the low voltage signal inputted from the outside.

It should be understood that, in the present specification, each embodiment is described in an incremental manner, and the same or similar parts between the embodiments are all referred to each other, and each embodiment is mainly described in a different point from other embodiments. The method embodiments are described in a relatively simple manner, and reference is made to the description of the system embodiments for relevant points. The invention is not limited to the specific steps and structures described above and shown in the drawings. Those skilled in the art will appreciate that various alterations, modifications, and additions may be made, or the order of steps may be altered, after appreciating the spirit of the present invention. Also, a detailed description of known method techniques is omitted here for the sake of brevity.

The functional modules in the above-described embodiments may be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, a plug-in, a function card, or the like. When implemented in software, the elements of the invention are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine readable medium or transmitted over transmission media or communication links by a data signal carried in a carrier wave. A "machine-readable medium" may include any medium that can store or transfer information.

Claims

1. A DCDC-based pre-detection device, characterized in that it comprises:

the first control module is connected with the second control module, the first control module stores a safety threshold interval, and the first control module is used for acquiring battery pack state parameters; 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 the main power module and 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 transmitting the low-voltage electric energy to the battery management module;

the second control module includes:

the signal isolation conversion unit is connected with the auxiliary power supply unit and is used for sending a high-voltage wake-up signal to the auxiliary power supply unit if an externally input low-voltage signal is detected;

the auxiliary power supply unit is connected with the control unit and is used for responding to the high-voltage wake-up signal under the condition of acquiring the first working electric energy to provide the second working electric energy for the control unit;

the control unit is used for controlling the main power module according to the control instruction under the condition of acquiring the second working electric energy.

2. The DCDC-based pre-detection apparatus of claim 1, further comprising:

the detection module is connected with the battery pack and is used for acquiring first sampling data from the battery pack;

The first control module is connected with the detection module and is also used for calculating the state parameters of the battery pack according to the first sampling data.

3. The DCDC-based pre-detection apparatus of claim 1, wherein said battery pack status parameter includes a voltage parameter of said battery pack,

the upper limit value of the safety threshold interval is set according to the overvoltage threshold of the battery pack, and the lower limit value of the safety threshold interval is set according to the undervoltage threshold of the battery pack.

4. The DCDC-based pre-detection apparatus of claim 1, wherein,

the auxiliary power supply unit is further configured to obtain first operating power provided by the battery pack and/or first operating power provided by the auxiliary power supply unit itself.

5. The DCDC-based pre-detection apparatus of claim 1, wherein,

the main power module comprises a forward transformer;

the auxiliary power supply unit comprises a flyback control subunit and a flyback transformer, and the control unit comprises a forward control subunit and a synchronous rectifier subunit;

the flyback control subunit is respectively connected with the flyback transformer and the forward control subunit, and is used for driving the flyback transformer to be intermittently switched on and off and providing the second working electric energy for the forward control subunit;

The flyback transformer is connected with the synchronous rectifier subunit and comprises a first primary coil and a first secondary coil, and the first primary coil is used for storing high-voltage electric energy under the condition that the flyback transformer is conducted; and under the condition that the flyback transformer is disconnected, the first primary side coil is used for converting the stored high-voltage electric energy into the low-voltage electric energy of the first secondary side coil, and providing second working electric energy for the synchronous rectifier subunit by utilizing the low-voltage electric energy of the first secondary side coil;

the forward control subunit is connected with the forward transformer and is used for controlling the high-voltage transmission line of the forward transformer to be alternately switched on and off, the second primary side coil of the high-voltage transmission line stores high-voltage electric energy under the condition that the high-voltage transmission line is disconnected, and the second primary side coil converts the stored high-voltage electric energy into low-voltage electric energy of the second secondary side coil of the low-voltage transmission line of the forward transformer under the condition that the high-voltage transmission line is conducted;

the synchronous rectifier subunit is connected with the low-voltage power transmission line and is used for controlling the second secondary coil to transmit the low-voltage power to the battery management module on the premise of acquiring second working power.

6. The DCDC-based pre-detection apparatus of claim 5, wherein,

the flyback control subunit comprises a flyback controller and a first switch component, the first switch component is arranged between the flyback controller and the flyback transformer,

the forward control subunit comprises a forward controller and a second switch component, the second switch component is arranged between the forward controller and the high-voltage transmission line,

the forward voltage transformer comprises a synchronous rectifier, a third switch component connected across the two ends of the second secondary winding, and a fourth switch component connected in series with the second secondary winding;

the flyback controller is connected with the synchronous rectifier and is used for outputting a first pulse width modulation signal to the first switch assembly so as to control the first switch assembly to be switched on and switched off at intervals and drive the flyback transformer to be switched on and switched off at intervals; and, further for synchronizing the first pulse width modulated signal to the synchronous rectifier;

the forward controller is used for outputting a second pulse width modulation signal to the second switch assembly so as to control the intermittent on-off of the high-voltage transmission line;

The synchronous rectifier is used for generating a third pulse width modulation signal based on the first pulse width modulation signal; and driving the third and fourth switching elements to be alternately turned on and off by using the third PWM signal, controlling the second secondary winding to transmit the low-voltage power to the battery management module,

the third pulse width modulation signal controls the switching state of the third switching component and the switching state of the fourth switching component to be mutually exclusive.

7. The DCDC-based pre-detection apparatus of claim 5, wherein,

the flyback transformer further includes a third primary winding,

wherein when the flyback transformer is on, the first primary winding couples a portion of the stored high-voltage electrical energy to the third primary winding,

the third primary coil is used for providing first working electric energy for the flyback control subunit by utilizing the part of high-voltage electric energy.

8. The DCDC-based pre-detection apparatus of claim 1, further comprising:

the battery management module is connected with the main power module and is used for responding to the low-voltage electric energy and controlling the conduction of a charging circuit between the battery pack and the outside so as to charge the battery pack by utilizing the electric energy corresponding to the low-voltage signal input from the outside.

9. The DCDC-based pre-detection method applied to the DCDC-based pre-detection apparatus according to claim 1, wherein the DCDC-based pre-detection method includes:

the first control module acquires the battery pack state parameters;

if the battery pack state parameter falls into the safety threshold interval, the first control module sends a control instruction to the second control module;

the second control module controls the main power module according to the control instruction;

under the control of the second control module, the main power module converts high-voltage electric energy of the battery pack into low-voltage electric energy and transmits the low-voltage electric energy to a battery management module;

the second control module controls the main power module according to the control instruction, and the second control module comprises:

if the signal isolation conversion unit of the second control module detects a low-voltage signal input from the outside, a high-voltage wake-up signal is sent to the auxiliary power supply unit of the second control module;

the auxiliary power supply unit responds to the high-voltage wake-up signal under the condition of acquiring first working electric energy and provides second working electric energy for the control units of the first control module and the second control module;

And the control unit controls the main power module according to the control instruction under the condition of acquiring the second working electric energy.

10. The DCDC-based pre-detection method of claim 9, further comprising:

the detection module acquires first sampling data from the battery pack;

the first control module obtains the battery pack state parameters, including:

the first control module calculates the battery pack state parameter according to the first sampling data.

11. The method for DCDC-based pre-detection of claim 9,

the battery pack status parameter includes a voltage parameter of the battery pack,

12. The DCDC-based pre-detection method of claim 9, further comprising:

the auxiliary power supply unit obtains first operating power supplied by the battery pack and/or first operating power supplied by the auxiliary power supply unit itself.

13. The method for DCDC-based pre-detection of claim 9,

the main power module comprises a forward transformer, the forward transformer comprises a high-voltage transmission line and a low-voltage transmission line,

the auxiliary power supply unit comprises a flyback control subunit and a flyback transformer, wherein the control unit comprises a forward control subunit and a synchronous rectifier subunit, and the flyback transformer comprises a first primary coil and a first secondary coil;

the second control module controls the main power module according to the control instruction, and specifically comprises:

the flyback control subunit provides a first driving signal for the flyback transformer at intervals and provides the second working electric energy for the forward control subunit;

the first primary coil stores high-voltage electric energy under the condition that the flyback control subunit provides the flyback transformer with the first driving signal;

under the condition that the flyback control subunit does not provide the first driving signal for the flyback transformer, the first primary side coil converts the stored high-voltage electric energy into the low-voltage electric energy of the first secondary side coil, and provides second working electric energy for the synchronous rectifier subunit by utilizing the low-voltage electric energy of the first secondary side coil;

The forward control subunit provides a second driving signal for the high-voltage transmission line of the forward transformer at intervals;

under the condition that the forward control subunit provides the second driving signal for the high-voltage transmission line, a second primary winding of the high-voltage transmission line converts high-voltage electric energy corresponding to the second driving signal into low-voltage electric energy of a second secondary winding of a low-voltage transmission line of the forward transformer;

and the synchronous rectifier subunit controls the second secondary coil to provide the low-voltage power to the battery management module on the premise of acquiring the second working power.

14. The method for DCDC-based pre-detection of claim 13,

the flyback control subunit comprises a flyback controller and a first switch component, the first switch component is arranged between the flyback controller and the flyback transformer, the forward control subunit comprises a forward controller and a second switch component, the second switch component is arranged between the forward controller and the high-voltage transmission line,

the synchronous rectifier subunit comprises a synchronous rectifier, a third switch assembly connected across the two ends of the second secondary coil, and a fourth switch assembly connected in series with the second secondary coil;

The DCDC-based pre-detection method comprises the following steps:

the flyback controller outputs a first pulse width modulation signal to the first switch assembly so as to intermittently provide the first driving signal to the flyback transformer by controlling the intermittent on-off of the first switch assembly; and, the flyback controller synchronizing the first pulse width modulated signal to the synchronous rectifier;

the forward controller outputs a second pulse width modulation signal to the second switch assembly so as to intermittently provide the second driving signal to the high-voltage transmission line by controlling the intermittent on-off of the second switch assembly;

the synchronous rectifier generates a third pulse width modulation signal based on the first pulse width modulation signal; and driving the third and fourth switching elements to be alternately turned on and off by using the third pulse width modulation signal, controlling the second secondary winding to transmit the low-voltage power of the second secondary winding to the battery management module,

15. The method for DCDC-based pre-detection of claim 13,

the flyback transformer further includes a third primary winding,

the DCDC-based pre-detection method further comprises the following steps:

when the flyback transformer is on, the first primary winding couples a portion of the stored high-voltage electrical energy to the third primary winding,

16. The DCDC-based pre-detection method of claim 9, further comprising:

and the battery management module responds to the low-voltage electric energy and controls the conduction of a charging circuit between the battery pack and the outside so as to charge the battery pack by utilizing the electric energy corresponding to the externally input low-voltage signal.