Novel pre-charging circuit

Abstract

A novel pre-charging circuit relates to the technical field of electronic circuits. Comprising a high-voltage pre-charging module which comprises a pre-charging resistor and a silicon controlled rectifier, and the pre-charging resistor is connected with the silicon controlled rectifier and used for receiving high-voltage current and limiting the magnitude of the high-voltage current; the low-voltage driving module is connected with the silicon controlled rectifier and is used for acquiring a control signal input from the outside and converting the control signal into a switching signal; and the silicon controlled rectifier is used for receiving the switching signal and the high-voltage current and outputting the high-voltage current according to the switching signal. By implementing the technical scheme provided by the invention, the stability and reliability of the pre-charging process can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic circuits, and in particular to a novel pre-charge circuit. BACKGROUND

[0002] In the field of new energy vehicles, power electronic devices, etc., the safe and stable operation of high-voltage circuit systems is of great importance. These systems usually contain large-capacity capacitors, and a pre-charge process is needed to gradually charge these capacitors when the system starts or switches to prevent sudden large currents from causing damage to the system. The pre-charge circuit plays a key role in this process, and its design directly affects the reliability, life and cost-effectiveness of the entire system.

[0003] Currently, the common pre-charge circuit design usually adopts a combination of pre-charge resistors and pre-charge relays. In this design, pre-charge resistors are used to limit the initial charging current, while pre-charge relays are responsible for controlling the start and end of the pre-charge process. When the pre-charge process starts, the current first passes through the pre-charge resistor, and when the capacitor voltage reaches a certain level, the pre-charge relay switches to connect the main loop directly, completing the entire pre-charge process.

[0004] However, this traditional pre-charge circuit control is complex. Since the pre-charge relay uses a mechanical contact structure, its control needs to consider factors such as the physical properties of the contact, switching timing, etc. This increases the complexity of the control circuit, affecting the stability and reliability of the pre-charge process. SUMMARY

[0005] The present application provides a novel pre-charge circuit that can improve the stability and reliability of the pre-charge process.

[0006] In the first aspect of the present application, a novel pre-charge circuit is provided, comprising: a high-voltage pre-charge module including a pre-charge resistor and a thyristor, wherein the pre-charge resistor is connected to the thyristor and is used to receive a high-voltage current and limit the size of the high-voltage current; a low-voltage drive module connected to the thyristor, used to obtain an externally input control signal and convert the control signal into a switching signal; the thyristor is used to receive the switching signal and the high-voltage current, and output the high-voltage current according to the switching signal.

[0007] Optionally, the isolation drive module further comprises: a switching drive unit for obtaining the externally input control signal and converting the control signal into a switching signal; An isolation control unit is connected with the switch driving unit and the thyristor, and is used to input the switch signal to the thyristor and electrically isolate the high-voltage pre-charging module and the low-voltage driving module.

[0008] Optionally, the switch driving unit further comprises: A signal generator is used to acquire the externally input control signal and generate a pulse width modulation signal according to the control signal. A driving switch tube is connected with the isolation control unit, and is used to receive the pulse width modulation signal and generate a switch signal according to the pulse width modulation signal.

[0009] Optionally, the signal generator is a 555 timer.

[0010] Optionally, the driving switch tube is any one of a triode or a MOS tube.

[0011] Optionally, the isolation control unit further comprises: A pulse transformer is connected with the thyristor and the switch driving unit, and is used to receive the switch signal, input the switch signal to the thyristor, and electrically isolate the high-voltage pre-charging module and the low-voltage driving module. A diode is connected with the pulse transformer and the thyristor, and is used to prevent the high-voltage current from flowing to the low-voltage driving module.

[0012] Optionally, the high-voltage pre-charging module is arranged on a first PCB board, the low-voltage driving module is arranged on a second PCB board, the first PCB board and the second PCB board are connected through a terminal post, and the first PCB board can bear a voltage greater than the second PCB board.

[0013] Optionally, the thyristor is a thyristor.

[0014] Optionally, the pre-charging resistor is a PCT resistor.

[0015] In the second aspect of the present application, a pre-charging relay is provided, which comprises any one of the novel pre-charging circuits.

[0016] In summary, the one or more technical solutions provided in the present application have at least the following technical effects or advantages: By employing a combination of a high-voltage pre-charge module and a low-voltage drive module, this novel pre-charge circuit achieves simplified control. Specifically, the pre-charge resistor in the high-voltage pre-charge module, used in conjunction with the thyristor, not only retains the function of limiting high-voltage current but also provides a more flexible control method. The introduction of the low-voltage drive module further optimizes the control process; it can directly receive externally input control signals and convert them into switching signals suitable for use with the thyristor.

[0017] The above technical solution significantly reduces the complexity of the control circuit, eliminating the need to consider factors such as contact characteristics and switching timing found in traditional mechanical relays. The thyristor, as the core control element, can precisely control the output of the high-voltage current based on the received switching signal, improving the stability and reliability of the pre-charging process. Furthermore, this simplified control method also reduces the difficulty and cost of system development, enhancing the adaptability and flexibility of the pre-charging circuit in different application scenarios. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a novel pre-charging circuit provided in an embodiment of this application.

[0020] Figure 2 This is a schematic diagram of another novel pre-charging circuit provided in the embodiments of this application.

[0021] Figure 3 This is a schematic diagram of another novel pre-charging circuit provided in an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the structure of a precharge relay provided in an embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Please refer to Figure 1 , Figure 1This is a schematic diagram of a novel pre-charging circuit provided in an embodiment of this application. Figure 1 As shown, the novel pre-charging circuit includes: The high-voltage precharge module includes a precharge resistor and a thyristor, wherein the precharge resistor is connected to the thyristor and is used to receive high-voltage current and limit the magnitude of high-voltage current. The low-voltage drive module, connected to the thyristor, is used to acquire external input control signals and convert the control signals into switching signals; A thyristor is used to receive switching signals and high-voltage current, and output high-voltage current according to the switching signal.

[0025] This refers to a circuit unit used to process and control high-voltage current. It can be understood as a circuit assembly composed of a pre-charge resistor and a thyristor, where the pre-charge resistor and the thyristor are connected in series to form a complete high-voltage processing unit.

[0026] The main function of the high-voltage precharge module is to receive and process high-voltage current, while simultaneously limiting and controlling it as necessary. As the first barrier preventing high-voltage current from entering the precharge circuit, this module limits the high-voltage current entering the system through a precharge resistor. This is crucial for protecting subsequent circuit components and ensuring the safety of the precharge process.

[0027] Furthermore, the high-voltage pre-charge module works in conjunction with a thyristor to achieve precise control of the pre-charge process. The thyristor controls the on / off state of the high-voltage current based on signals from the low-voltage drive module, thereby achieving voltage balancing. Particularly when using a pre-charge resistor, the module can automatically adjust its resistance value according to the current magnitude, providing additional overload protection. During system power-on, the high-voltage pre-charge module gradually charges the large-capacity capacitor in the system by controlling the current flow, achieving voltage balance between the input and load terminals and preventing damage to the system from instantaneous high current.

[0028] A pre-charge resistor is a resistive element used to limit and control the current during the pre-charge process. In a high-voltage pre-charge module, it is a resistor assembly connected in series with a silicon controlled rectifier (SCR). The pre-charge resistor is primarily used to limit the current flowing through the circuit in the initial stage of the pre-charge process, preventing potential damage to the system from sudden large currents. By appropriately selecting the resistance value, the pre-charge resistor can ensure a smooth pre-charge process, avoiding voltage spikes and current surges. The pre-charge resistor also helps achieve voltage balance between the input and load terminals, allowing large capacitors in the system to charge gradually, thereby protecting subsequent circuit components.

[0029] Furthermore, the presence of the pre-charging resistor provides a certain time buffer for the entire pre-charging process, giving the control system sufficient time to monitor and adjust the pre-charging status. By rationally designing the parameters of the pre-charging resistor, the pre-charging time can be optimized, improving the overall efficiency and reliability of the system.

[0030] In one optional embodiment, the pre-charge resistor can be a PTC resistor. A PTC resistor is a positive temperature coefficient resistor, a special type of resistive element whose resistance increases with temperature. In this embodiment, it can be understood as a pre-charge resistor capable of adaptively adjusting its resistance value according to current changes. The PTC resistor is primarily used to provide a more intelligent and safer current limiting function during pre-charging. When an increase in current causes the PTC resistor's temperature to rise, its resistance value automatically increases, thereby limiting more current and achieving adaptive current control.

[0031] These characteristics allow PTC resistors to rapidly increase their resistance value when abnormally high currents occur, effectively preventing circuit overload. Simultaneously, PTC resistors possess excellent surge protection, capable of absorbing transient voltages in the system and protecting downstream circuit components. By adaptively adjusting the current, PTC resistors reduce stress in the circuit, helping to extend the lifespan of the entire precharge system. Compared to traditional fixed-value resistors, the adaptive characteristics of PTC resistors make the precharge process safer and more reliable, reducing system failures caused by current fluctuations. Furthermore, the adaptive characteristics of PTC resistors can simplify the design of precharge circuits to some extent, reducing the need for additional protection circuitry.

[0032] Correspondingly, a thyristor refers to a controllable semiconductor switching device. In the embodiments of this application, the thyristor is used to control the on / off state of the pre-charge circuit, determining whether to allow high-voltage current to pass based on the received control signal. The thyristor possesses high-speed switching characteristics and high current carrying capacity, enabling precise control of current flow during the pre-charge process. Compared to traditional mechanical relays, the thyristor has no mechanical contacts, thus offering a longer service life and higher reliability. It can withstand frequent switching operations without mechanical wear, which is particularly important for systems requiring frequent pre-charge operations. Furthermore, the thyristor's fast switching speed allows for precise control of the pre-charge process, helping to optimize pre-charge time and efficiency.

[0033] In an optional embodiment, the thyristor can be used as the silicon controlled rectifier (SCR). A thyristor is a four-layer, three-terminal semiconductor switching device, also known as a silicon controlled rectifier (SCR). In this embodiment, it can be understood as a current-type thyristor switch capable of switching high-voltage current on and off via a control signal. The thyristor is used to precisely control the current flow in the pre-charge circuit and is the core switching element for realizing the pre-charge function.

[0034] Thyristors possess unique triggering characteristics, only turning on when the anode voltage is positive and the gate receives an appropriate trigger signal. Once turned on, the thyristor remains on even after the gate signal is removed, until the anode current drops below the holding current. This characteristic makes thyristors ideal for current control in pre-charge circuits. In the embodiments of this application, the thyristor is connected in series with a pre-charge resistor, and precise control of the pre-charge process is achieved by controlling the thyristor's on and off states.

[0035] The high-speed switching characteristics of thyristors enable them to respond quickly to control signals, achieving rapid switching of the precharge circuit. This helps optimize precharge time and improve the overall system efficiency. Simultaneously, thyristors possess a large current carrying capacity and excellent voltage withstand characteristics, meeting the requirements of high-voltage precharge circuits. Compared to mechanical relays, thyristors have no mechanical contacts, thus offering a longer service life and higher reliability, making them particularly suitable for systems requiring frequent precharge operations.

[0036] Furthermore, thyristors exhibit relatively stable temperature characteristics, maintaining good performance over a wide temperature range, making them particularly suitable for pre-charging circuits in complex environments such as automotive. Thyristors also possess low on-state voltage drop, reducing power losses during pre-charging and improving system energy efficiency.

[0037] In summary, the pre-charge resistor and the thyristor work together in the pre-charge circuit: the pre-charge resistor first limits the initial current to prevent sudden large current surges; while the thyristor precisely controls the current flow based on the control signal. This combination not only improves the safety and reliability of the pre-charge process but also enhances the system's flexibility and controllability. By using these two components, the novel pre-charge circuit of this application embodiment can significantly improve system performance and extend service life while ensuring functional implementation.

[0038] The low-voltage drive module refers to a circuit unit used for processing and converting control signals. In the embodiments of this application, it can be understood as a circuit component responsible for receiving external control signals and converting them into signals suitable for driving the thyristor. The low-voltage drive module is mainly used to achieve high-low voltage isolation and signal conversion, ensuring the safe operation and precise control of the entire pre-charge circuit.

[0039] Specifically, the low-voltage drive module receives low-voltage control signals from an external control system. These signals are typically logic-level voltages, insufficient to directly drive the high-voltage side thyristors. The low-voltage drive module converts these low-voltage signals into pulse signals suitable for triggering the thyristors. During this process, the low-voltage drive module also needs to ensure electrical isolation between the high-voltage and low-voltage sides to prevent damage to the low-voltage control circuitry from the high voltage.

[0040] Through the above design, the low-voltage drive module enables precise control of the high-voltage pre-charging process while ensuring the safety of the low-voltage control system. It allows the entire pre-charging circuit to be easily integrated into existing control systems, improving system compatibility and flexibility. Furthermore, the presence of the low-voltage drive module simplifies the overall system design, allowing the high-voltage and low-voltage control sections to be developed and optimized independently, thereby improving system maintainability and upgradeability.

[0041] Please refer to Figure 2 , Figure 2 This is a schematic diagram of another novel pre-charging circuit provided in an embodiment of this application. For example... Figure 2 As shown, based on the above embodiments, as an optional embodiment, the isolation driver module further includes: The switch driver unit is used to acquire external input control signals and convert the control signals into switch signals; The isolation control unit is connected to the switch drive unit and the thyristor respectively. It is used to input the switch signal to the thyristor and to provide electrical isolation between the high voltage precharge module and the low voltage drive module.

[0042] The switch driver unit refers to a circuit component used to process and convert control signals. In the embodiments of this application, it can be understood as a circuit unit responsible for receiving low-voltage control signals from external input and converting them into switching signals suitable for driving the thyristor. The switch driver unit is mainly used to condition and amplify the control signals, ensuring that the generated switching signals can effectively trigger the thyristor, thereby precisely controlling the pre-charge process.

[0043] Specifically, the switch driver unit plays a crucial role in signal processing and conversion within the pre-charge circuit. It first receives low-voltage control signals from the external control system; these signals are typically logic-level voltages and may range from simple switching commands to more complex control strategies. The switch driver unit then processes these signals, potentially involving amplification, shaping, filtering, or modulation. The goal of this process is to generate a signal that can effectively drive the thyristor, typically taking into account the thyristor's triggering characteristics and the operating environment of the pre-charge circuit.

[0044] In practical applications, the design of a switch driver unit needs to consider several factors. First, it must be able to accurately identify and process various possible input signals, including digital or analog signals of different levels. Second, it needs to have sufficient driving capability to ensure that the generated switching signal can reliably trigger the thyristor. Furthermore, the switch driver unit also needs to have good anti-interference capabilities to cope with complex electromagnetic environments, especially in applications such as automotive.

[0045] Correspondingly, the isolation control unit refers to a circuit component used to achieve electrical isolation and signal transmission. In the embodiments of this application, it can be understood as a circuit unit responsible for safely transmitting the switching signal generated by the switching drive unit to the thyristor, while simultaneously achieving electrical isolation between the high-voltage precharge module and the low-voltage drive module. The isolation control unit is mainly used to ensure the accurate transmission of control signals and the safe isolation between high and low voltage circuits, thereby improving the reliability and safety of the precharge circuit.

[0046] Specifically, the isolation control unit in the pre-charge circuit is responsible for receiving switching signals from the switch drive unit and transmitting these signals to the thyristor on the high-voltage side using specific isolation techniques. This process needs to ensure signal integrity and timing characteristics to ensure that the thyristor can perform switching operations as expected. Secondly, the isolation control unit also undertakes the important task of electrical isolation, establishing an electrical barrier between the high-voltage pre-charge module and the low-voltage drive module, effectively preventing high-voltage interference or damage to the low-voltage control circuit.

[0047] In practical applications, isolation control units are typically designed using technologies such as optocouplers, magnetic coupling, or capacitive coupling. These technologies can achieve effective isolation between high- and low-voltage circuits while ensuring signal transmission. For example, optocouplers use optical signals to transmit information, achieving electrical isolation; while magnetic coupling technology uses magnetic fields to achieve contactless signal transmission. The choice of isolation technology depends on specific application requirements, such as isolation voltage level, signal transmission speed, and environmental factors.

[0048] The presence of the isolation control unit significantly improves the safety and reliability of the pre-charging circuit. Through effective electrical isolation, it greatly reduces the risk of high-voltage interference to low-voltage circuits, protecting the low-voltage control circuit and the safety of operators. Simultaneously, the isolation control unit also enhances the system's anti-interference capability, reducing the impact of electromagnetic interference on control signals, making the pre-charging process more stable and reliable.

[0049] Please refer to Figure 3 , Figure 3 This is a schematic diagram of another novel pre-charging circuit provided in an embodiment of this application. Figure 3 As shown, based on the above embodiments, as an optional embodiment, the switch driving unit further includes: A signal generator is used to acquire externally input control signals and generate pulse width modulation signals based on the control signals. The drive switch is connected to the isolation control unit to receive pulse width modulation signals and generate switching signals based on the pulse width modulation signals.

[0050] A signal generator is an electronic circuit or device capable of generating specific waveforms or signals. In the embodiments of this application, it can be understood as a circuit unit capable of receiving external control signals and generating corresponding pulse width modulation (PWM) signals. The signal generator is mainly used to convert externally input control commands into precise and controllable PWM signals, providing appropriate inputs for driving the switching transistors, thereby achieving fine control of the pre-charge process.

[0051] Specifically, the signal generator receives control signals from an external control system in the pre-charge circuit. These signals may be simple switching commands or digital or analog signals containing complex control strategies. The signal generator then generates corresponding PWM signals based on these input signals, using internal logic circuitry or a microcontroller. This process involves signal parsing, processing, and re-encoding to ensure that the generated PWM signal accurately reflects the intent of the external control commands.

[0052] In practical applications, the design of a signal generator needs to consider several factors. First, it must have sufficient processing power and response speed to process input signals in real time and generate corresponding PWM outputs. Second, the signal generator needs to be able to generate PWM signals with precise frequency and duty cycle, which directly affects the control accuracy of the precharge process. Furthermore, the signal generator should also have good programmability and flexibility to adapt to different control strategies and operating conditions.

[0053] The presence of a signal generator significantly improves the control precision and flexibility of the pre-charge circuit. By converting external control commands into PWM signals, it provides the system with a continuously adjustable control method, enabling precise adjustment of the thyristor's on-time and pre-charge current. This fine control not only optimizes the pre-charge process but also improves the overall system efficiency and safety. Simultaneously, the programmable nature of the signal generator provides greater flexibility, allowing the pre-charge circuit to easily adapt to different application requirements and operating conditions.

[0054] In one alternative embodiment, the signal generator can be a 555 timer. The 555 timer is an integrated timer chip widely used in electronic circuits. In this embodiment, it can generate a precise PWM signal based on an external control signal, providing a reliable control input for driving the switching transistor, thereby enabling fine adjustment of the precharge process.

[0055] The 555 timer can be set to multiple operating modes, among which the oscillator mode is particularly suitable for generating PWM signals. Through an external resistor and capacitor network, the frequency and duty cycle of the output signal can be flexibly set, achieving precise control of the precharge process. The advantages of this design are its simple structure and ease of use; stable signal output can be achieved with only a few external components. Furthermore, the 555 timer exhibits high operational stability and reliability, maintaining good performance over a wide temperature and voltage range, which is especially important for applications in complex environments such as automotive electronics.

[0056] Correspondingly, a drive switch refers to a semiconductor device used to control the switching of high-power circuits. In the embodiments of this application, it can be understood as an electronic switching element that receives pulse width modulation signals and converts them into switching signals suitable for driving the thyristor. The drive switch is mainly used to amplify and regulate the PWM signal output by the signal generator, ensuring that the generated switching signal can effectively trigger the thyristor, thereby achieving precise control of the pre-charge process.

[0057] In this pre-charge circuit, the drive switch receives PWM signals from the signal generator. These signals are typically low-power, low-voltage control signals. The drive switch converts these signals into switching signals with sufficient voltage and current strength to ensure effective triggering and control of the high-voltage side thyristor. This process involves not only signal power amplification but may also include voltage level conversion to match the thyristor's triggering requirements.

[0058] The selection and design of the driver switch requires consideration of several factors. First, it must have a sufficiently fast switching speed to accurately transmit the timing characteristics of the PWM signal. Second, the driver switch needs to have appropriate voltage and current handling capabilities to meet the driving requirements of the thyristor. Furthermore, the driver switch should also possess good linearity and temperature stability to ensure consistent performance under various operating conditions.

[0059] In one alternative implementation, the driving switch can be a variety of semiconductor devices, such as transistors or MOSFETs. The choice of which type of device to use depends on the specific application scenario and system requirements. In the application of pre-charging circuits in new energy vehicles, the selection of these two devices mainly depends on factors such as the operating voltage, switching frequency, power requirements, and cost of the pre-charging circuit.

[0060] For low-voltage, low-power precharge applications, transistors may be a suitable choice. Transistors have a low on-state voltage drop, providing high efficiency in low-voltage applications, while typically being less expensive, making them an economical solution for mass production. In some precharge scenarios where switching speed requirements are not particularly high, such as in the precharge circuits of some small electric vehicles or low-power electronic devices, transistors can provide sufficient performance.

[0061] However, in most pre-charging circuit applications of new energy vehicles, MOSFETs are generally the preferred choice. This is because new energy vehicles typically use high-voltage systems (such as 400V or 800V), which have high requirements for switching speed and efficiency. MOSFETs have significant advantages in these aspects: they have high voltage withstand capability, easily handling voltages of several hundred volts; their switching speed is much faster than that of transistors, enabling high-frequency PWM control, improving the accuracy and response speed of the pre-charging process; and in high-voltage applications, the on-resistance of MOSFETs is typically lower than that of transistors, reducing power loss and improving system efficiency.

[0062] Considering the specific requirements of pre-charging circuits in new energy vehicles, such as high reliability, high efficiency, and fast response, the advantages of MOSFETs are even more pronounced. For example, in a 400V electric vehicle system, the pre-charging circuit may need to complete the pre-charging process within milliseconds while handling tens of amperes of current. In this case, using a high-voltage MOSFET as the drive switch can provide fast switching speed and low conduction losses, ensuring efficient and precise control of the pre-charging process.

[0063] Furthermore, the high input impedance of MOSFETs means they require very little drive current, simplifying drive circuit design and reducing power consumption. They typically offer better temperature stability, which is especially important in complex thermal environments such as automotive. In scenarios requiring high current handling, MOSFETs are easier to connect in parallel, increasing the system's current handling capability.

[0064] In summary, the use of the drive switch improves the control accuracy of the pre-charge circuit. By precisely amplifying and transmitting the PWM signal, the drive switch ensures accurate triggering of the SCR, thereby achieving fine control over the pre-charge process. Secondly, the drive switch enhances system reliability. It provides a buffer between the low-voltage control circuit and the high-voltage power circuit, helping to protect the low-voltage side control circuit from high-voltage interference.

[0065] like Figure 3 As shown, based on the above embodiments, as an optional embodiment, the isolation control unit further includes: The pulse transformer is connected to the thyristor and the switch drive unit respectively. It is used to receive the switch signal, input the switch signal to the thyristor, and provide electrical isolation between the high voltage precharge module and the low voltage drive module. The diodes, connected to the pulse transformer and the thyristor respectively, are used to prevent high-voltage current from flowing to the low-voltage drive module.

[0066] The pulse transformer refers to a transformer specifically designed for transmitting pulse signals. Its structure and magnetic materials are specially optimized to meet the transmission requirements of high-frequency pulse signals. In the embodiments of this application, it can be understood as an electromagnetic device used to achieve isolation between high and low voltage circuits and transmission of control signals. The pulse transformer is mainly used to safely and effectively transmit the control pulse signals generated by the low-voltage drive module to the thyristor on the high-voltage side, while simultaneously achieving electrical isolation between the high-voltage pre-charge module and the low-voltage drive module.

[0067] Specifically, the primary winding of the pulse transformer is connected to the output of the low-voltage drive module, receiving the PWM control signal generated by the switching drive unit. The secondary winding is connected to the control terminal of the thyristor on the high-voltage side through appropriate circuitry. When the primary winding receives a pulse signal, a corresponding pulse voltage is generated in the secondary winding through electromagnetic induction, thereby triggering the switching action of the thyristor.

[0068] Furthermore, the introduction of diodes enhances system safety. Connected in series between the secondary winding of the pulse transformer and the thyristor, it provides unidirectional conduction. This design prevents high-voltage current from flowing backward through the pulse transformer into the low-voltage drive module, providing additional protection for the system. When selecting diodes, parameters such as reverse withstand voltage, forward voltage drop, and switching speed must be considered to ensure reliable operation under high-voltage conditions without affecting control signal transmission.

[0069] like Figure 3 As shown, based on the above embodiments, as an optional embodiment, the high-voltage pre-charge module is disposed on the first PCB board, the low-voltage drive module is disposed on the second PCB board, the first PCB board and the second PCB board are connected by terminals, and the voltage that the first PCB board can bear is greater than that of the second PCB board.

[0070] Specifically, the necessity of the aforementioned separate design stems from the coexistence of high-voltage and low-voltage systems in the pre-charging circuit of new energy vehicles. In practical applications, the high-voltage pre-charging module needs to handle hundreds of volts, while the low-voltage drive module typically operates within a voltage range of tens of volts. Placing these two modules on different PCBs not only achieves physical isolation and enhances safety, but also allows for optimized design for their respective voltage levels, improving the overall performance and reliability of the system.

[0071] Furthermore, the first PCB board employs high-voltage PCB design technology, including wider trace spacing, thicker copper foil, and special insulating materials, to ensure its ability to safely carry high-voltage current. This PCB board primarily houses components of the high-voltage pre-charge module, such as pre-charge resistors and thyristors. The second PCB board uses a conventional low-voltage PCB design, mainly housing components of the low-voltage drive module, such as signal generators and drive switching transistors. The two PCB boards are connected via terminal blocks, a connection method that not only provides the necessary mechanical strength but also allows for flexible adjustment of the distance between the two modules when necessary.

[0072] Furthermore, the design of the terminals requires special attention. They must not only transmit control signals but also ensure safe isolation between high and low voltage. Materials with sufficient insulation strength are typically selected, and safety factors such as creepage distances and clearances are considered. In addition, the arrangement of the terminals must also consider EMC (electromagnetic compatibility) requirements to reduce electromagnetic interference.

[0073] The above design improves system safety. By physically separating the high-voltage and low-voltage circuits, the potential harm of high voltage to low-voltage circuits is significantly reduced. Secondly, this modular design enhances system maintainability and scalability. When upgrades or repairs are needed, the high-voltage or low-voltage section can be addressed specifically without affecting the entire system. Furthermore, the separate design allows the two modules to employ different heat dissipation strategies, which helps improve the system's thermal management efficiency.

[0074] Please refer to Figure 4 , Figure 4 The present application provides a schematic diagram of a precharge relay. Based on the above embodiments, as an optional embodiment, the present application also proposes a precharge relay, including the novel precharge circuit in the above embodiments.

[0075] Specifically, the novel pre-charging circuit can be integrated into the pre-charging relay housing for encapsulation. This design aims to achieve compatible replacement with commonly used pre-charging relays. Currently, most electric vehicles use standardized pre-charging relays, which have uniform specifications in terms of size, interface, and installation method. However, traditional pre-charging relays have limitations in terms of control accuracy, intelligence, and energy efficiency. This application cleverly resolves the contradiction between technological upgrades and compatibility by integrating an advanced pre-charging circuit into a standard relay housing.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A novel pre-charging circuit, characterized in that, include: A high-voltage precharge module includes a precharge resistor and a thyristor, wherein the precharge resistor is connected to the thyristor and is used to receive high-voltage current and limit the magnitude of the high-voltage current; A low-voltage drive module, connected to the thyristor, is used to acquire externally input control signals and convert the control signals into switching signals; The thyristor is used to receive the switching signal and the high-voltage current, and to output the high-voltage current according to the switching signal.

2. The novel pre-charging circuit according to claim 1, characterized in that, The isolation driver module also includes: A switch driving unit is used to acquire the externally input control signal and convert the control signal into a switch signal; An isolation control unit is connected to both the switch drive unit and the thyristor, and is used to input the switch signal to the thyristor and to provide electrical isolation between the high-voltage precharge module and the low-voltage drive module.

3. The novel pre-charging circuit according to claim 2, characterized in that, The switch driving unit further includes: A signal generator is used to acquire the externally input control signal and generate a pulse width modulation signal based on the control signal; A drive switch transistor is connected to the isolation control unit to receive the pulse width modulation signal and generate a switching signal based on the pulse width modulation signal.

4. The novel pre-charging circuit according to claim 3, characterized in that, The signal generator is a 555 timer.

5. The novel pre-charging circuit according to claim 3, characterized in that, The driving switch can be either a transistor or a MOSFET.

6. The novel pre-charging circuit according to claim 2, characterized in that, The isolation control unit also includes: A pulse transformer is connected to the thyristor and the switch drive unit respectively, for receiving the switch signal, inputting the switch signal to the thyristor, and electrically isolating the high-voltage precharge module and the low-voltage drive module; The diodes are connected to the pulse transformer and the thyristor respectively, to prevent the high-voltage current from flowing to the low-voltage drive module.

7. The novel pre-charging circuit according to claim 1, characterized in that, The high-voltage pre-charge module is mounted on the first PCB board, and the low-voltage drive module is mounted on the second PCB board. The first PCB board and the second PCB board are connected by terminals. The voltage that the first PCB board can bear is greater than that of the second PCB board.

8. The novel pre-charging circuit according to claim 1, characterized in that, The thyristor is a silicon controlled rectifier.

9. The novel pre-charging circuit according to claim 1, characterized in that, The pre-charge resistor is a PCT resistor.

10. A pre-charged relay, characterized in that, The novel pre-charging circuit includes any one of claims 1 to 9.

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