High-voltage pre-charging circuit and method

Abstract

The embodiment of the invention discloses a high-voltage pre-charging circuit and method. The circuit comprises a voltage stabilizing module, a sampling module, a comparison module, a bypass module and a pre-charging execution module, wherein an external power supply pre-charges a target charging element through the pre-charging execution module; the voltage stabilizing module is configured to convert an input voltage from an external power supply into a reference voltage and output the reference voltage to the comparison module; the sampling module is configured to output a sampling voltage to the comparison module according to the collected voltage of the pre-charging execution module; the comparison module is configured to compare the sampling voltage with the reference voltage and control the on or off of the bypass module according to a comparison result; and the bypass module is configured to bypass the pre-charging execution module after being conducted, so that the external power supply stops pre-charging the target charging element. According to the embodiment of the invention, pre-charging can be realized without external component control conditions, the influence on the original design is small, and the cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile electrical control, and in particular to a high-voltage pre-charging circuit and method. BACKGROUND

[0002] Pre-charging is a function commonly required by components involving power conversion, such as automobiles, photovoltaics, and power converters, and the main purpose is to prevent the situation that, during the power-on process of a high-voltage bus, the initial voltage of the internal capacitor of a component is zero, the instantaneous charging current is too large, and the line or internal device of the component is instantaneously overloaded, resulting in damage or reduced service life.

[0003] The existing pre-charging method is mainly realized by a relay and a control circuit thereof. The relay and the control circuit occupy a large space and have a high cost. An additional signal needs to be introduced in the pre-charging circuit for control, which increases the complexity of the system and may potentially affect the performance of the original component. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a high-voltage pre-charging circuit and method to realize pre-charging without external component control conditions and with less impact on the original design and low cost.

[0005] In a first aspect, the present application provides a high-voltage pre-charging circuit, which includes a voltage stabilizing module, a sampling module, a comparison module, a bypass module, and a pre-charging execution module. An external power supply pre-charges a target charging element through the pre-charging execution module. The voltage stabilizing module is configured to convert an input voltage from the external power supply into a reference voltage and output the reference voltage to the comparison module. The sampling module is configured to output a sampling voltage to the comparison module according to the voltage of the pre-charging execution module collected. The comparison module is configured to compare the sampling voltage with the reference voltage and control the on or off of the bypass module according to the comparison result. The bypass module is configured to bypass the pre-charging execution module after being turned on, so that the external power supply stops pre-charging the target charging element.

[0006] In at least some embodiments of the present application, The sampling module is further configured to output a constant voltage value as the sampling voltage when the voltage of the pre-charging execution module collected is within a preset range, and output a divided voltage value as the sampling voltage when the voltage of the pre-charging execution module collected exceeds the preset range. The comparison module is further configured to control the bypass module to be off when the sampling voltage is greater than the reference voltage, and control the bypass module to be on when the sampling voltage is less than the reference voltage. Wherein, the constant voltage value is greater than the reference voltage, and the input and output of the sampling module are in a non-linear relationship. At this time, while ensuring that the output of the comparison module is low, the output voltage of the sampling module is limited to protect the input port of the comparison module. The maximum value of the voltage divider is slightly greater than the reference voltage, and the input and output of the sampling module are in a linear relationship. The reference voltage is within the range of the voltage divider. While ensuring that the voltage range in the linear region is as small as possible (while maximizing the input-output ratio in the linear region), the changes in the input voltage of the sampling module can be better reflected, resulting in higher accuracy and better control effect.

[0007] In at least some embodiments of this application, The voltage regulator module includes a first resistor, a first Zener diode, a second resistor, and a third resistor; The first resistor and the first Zener diode are connected in series and in parallel across the external power supply. The second resistor and the third resistor are connected in series and in parallel across the first Zener diode; the connection node between the second resistor and the third resistor is configured to output the reference voltage to the comparator module; An external power supply is configured to power the comparator module through the first resistor and the first Zener diode.

[0008] In at least some embodiments of this application, The sampling module includes a fourth resistor, a second Zener diode, and a fifth resistor; The fourth resistor and the second Zener diode are connected in series and in parallel with the precharge execution module; The fifth resistor is connected in parallel across the second Zener diode and in series with the fourth resistor; The connection node between the fourth resistor and the second Zener diode is configured to output the sampled voltage to the comparison module.

[0009] In at least some embodiments of this application, The comparison module includes a comparator; the non-inverting input of the comparator is connected to the output of the voltage regulator module and configured to receive the reference voltage; the inverting input of the comparator is connected to the output of the sampling module and configured to receive the sampled voltage. The comparator is configured to output a low level to control the bypass module to turn off when the sampled voltage is greater than the reference voltage, and to output a high level to control the bypass module to turn on when the sampled voltage is less than the reference voltage.

[0010] In at least some embodiments of this application, The bypass module includes an NMOS transistor, which is connected in parallel with the precharge execution module; the gate of the NMOS transistor is connected to the output of the comparator.

[0011] In at least some embodiments of this application, The pre-charge execution module includes a pre-charge resistor, and an external power supply, a target charging element, and the pre-charge resistor are connected in series to form a pre-charge circuit.

[0012] In at least some embodiments of this application, The high-voltage pre-charging circuit also includes an external expansion module, which is configured to connect to an external controller. The external controller is configured to obtain the pre-charging status of the high-voltage pre-charging circuit or to perform pre-charging control on the high-voltage pre-charging circuit through the external expansion module.

[0013] In a second aspect, this application provides a high-voltage pre-charging method based on a high-voltage pre-charging circuit as described in any one of the first aspects; the method includes: When the external power supply is turned on, the target charging element is pre-charged through the pre-charge execution module; During the pre-charging process, the voltage regulator module converts the input voltage from the external power supply into a reference voltage and outputs it to the comparison module; the sampling module outputs a sampled voltage to the comparison module based on the voltage collected from the pre-charging execution module; the comparison module compares the sampled voltage with the reference voltage and controls the bypass module to turn on or off based on the comparison result. When the bypass module is turned on, the precharge execution module is bypassed, so that the external power supply stops precharging the target charging element.

[0014] In at least some embodiments of this application, The method further includes: When the voltage of the precharge execution module acquired by the acquisition module is within a preset range, the output sampling voltage is a constant voltage value; when the voltage of the precharge execution module acquired by the acquisition module exceeds the preset range, the output sampling voltage is a voltage divider value. When the sampled voltage is greater than the reference voltage, the comparison module controls the bypass module to turn off; when the sampled voltage is less than the reference voltage, the comparison module controls the bypass module to turn on. Wherein, the constant voltage value is greater than the reference voltage, and the input and output of the sampling module are in a non-linear relationship. At this time, while ensuring that the output of the comparison module is low, the output voltage of the sampling module is limited to protect the input port of the comparison module. The maximum value of the voltage divider is slightly greater than the reference voltage, and the input and output of the sampling module are in a linear relationship. The reference voltage is within the range of the voltage divider. While ensuring that the voltage range in the linear region is as small as possible (while maximizing the input-output ratio in the linear region), the changes in the input voltage of the sampling module can be better reflected, resulting in higher accuracy and better control effect.

[0015] The above-described one or more embodiments of this application have at least one or more of the following beneficial effects: In implementing the technical solution of this application, the automatic control of precharging of the target charging element is achieved through the cooperation of the voltage regulation module, sampling module, comparison module, bypass module and precharge execution module. It does not require the integration of microcontroller system, isolation module and other modules in the module, thus eliminating the need for external control components. It has little impact on existing components and circuit design, lower cost, high flexibility and is suitable for external precharge scenarios.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Furthermore, similar numbers in the drawings are used to denote similar components, wherein: Figure 1 This is a schematic diagram of the high-voltage pre-charging circuit principle structure according to one embodiment of this application; Figure 2 This is a schematic diagram of the pre-charging process of a high-voltage pre-charging circuit according to one embodiment of this application; Figure 3 This is a schematic diagram of a high-voltage pre-charge circuit according to one embodiment of this application; Figure 4 This is a schematic diagram of the simulation waveform of a high-voltage pre-charge circuit according to one embodiment of this application; Figure 5 This is a schematic diagram of an external level conversion circuit for a high-voltage pre-charge circuit according to one embodiment of this application; Figure 6 This is a schematic diagram of an external MCU circuit for a high-voltage pre-charge circuit, which is one embodiment of this application. Detailed Implementation

[0018] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0019] As described in the background section, taking commercial vehicles as an example, many existing commercial vehicle solutions do not have a comprehensive pre-charging function plan, which necessitates that components possess pre-charging capabilities. For component manufacturers, passenger vehicle components can cover the functions of many similar components in commercial vehicles. Since almost all passenger vehicles have overall pre-charging function planning at the vehicle level, there is no need for redundant design at the product level. Therefore, most products shared by passenger and commercial vehicles do not consider pre-charging functionality in their product system design. In this case, when applied to commercial vehicles, it is necessary to integrate pre-charging functionality separately into the product or use an external pre-charging module. External pre-charging modules require high flexibility and, to a certain extent, simple autonomous control to minimize the impact on the performance and modification of the original product circuitry. However, traditional pre-charging solutions have the following problems: The precharge module integrates a microcontroller system, power supply, sampling and isolation modules, and uses the integrated microcontroller system for precharge control. This solution allows the circuit to be free from external control and achieve simple autonomous control with almost no impact on the original design, but the integrated system cost is high. The precharge module requires control by the microcontroller system of the component, as well as the power supply and sampling modules of the component. This solution requires additional signals for control, does not have the conditions to be controlled independently of external components, makes significant changes to the original design, increases the complexity of the system, and has the potential risk of affecting the performance of the original components.

[0020] Based on this, this application proposes a high-voltage pre-charging circuit, which achieves automatic control of pre-charging of the target charging element through the cooperation of a voltage stabilizing module, a sampling module, a comparison module, a bypass module and a pre-charging execution module. This eliminates the need for external control components, does not require the integration of a microcontroller system, isolation modules, etc. into the module, has little impact on existing designs, and is low in cost.

[0021] See appendix Figure 1 In one or more embodiments, a high-voltage pre-charging circuit of this application includes a voltage regulator module, a sampling module, a comparison module, a bypass module, and a pre-charging execution module, wherein an external power supply pre-charges the target charging element through the pre-charging execution module; The voltage regulator module is configured to convert the input voltage from an external power supply into a reference voltage and output it to the comparator module; The sampling module is configured to output a sampled voltage to the comparison module based on the voltage collected from the bypass module; The comparison module is configured to compare the sampled voltage with the reference voltage and control the bypass module to turn on or off based on the comparison result; The bypass module is configured to bypass the precharge execution module after being turned on, so that the external power supply stops precharging the target charging element.

[0022] It is understood that in the high-voltage pre-charging circuit of this application, after the power supply is powered on, the target charging element can be pre-charged through the pre-charging execution module. During the pre-charging process, the voltage regulator module can convert the voltage of the external power supply into another voltage for output. That is, by setting the voltage regulator module, the external power supply voltage can be converted into a preset target voltage output. Therefore, this preset target voltage can be provided as a reference voltage to the comparison module. During pre-charging and overcharging, since the external power supply pre-charges the target charging element through the pre-charging execution module, the voltage of the pre-charging execution module can reflect the pre-charging state of the target charging element (the initial voltage of the pre-charging execution module is the voltage of the external power supply; as the pre-charging time increases, the voltage of the target charging element gradually increases, and the voltage of the pre-charging execution module gradually decreases accordingly). Therefore, the sampling module can obtain the current pre-charging state by acquiring the voltage of the pre-charging execution module, thereby providing a basis for controlling the pre-charging state of the entire pre-charging circuit.

[0023] Specifically, regarding the control of the pre-charge state: the sampling module can output a sampled voltage to the comparison module based on the voltage of the pre-charge execution module. This sampled voltage can be a voltage converted according to the voltage of the pre-charge execution module to meet the pre-charge target requirements and the design and usage requirements of the corresponding devices. The comparison module compares the sampled voltage with the reference voltage and obtains the comparison result. For example, if the sampled voltage is greater than or less than the reference voltage, it controls the conduction or deactivation of the bypass module. The bypass module can bypass the pre-charge execution module, which is equivalent to short-circuiting the pre-charge execution module after it is turned on, so that the external power supply can no longer pre-charge the target charging element through the pre-charge execution module, and automatically controls the exit of the pre-charge state after the pre-charge is completed.

[0024] Specifically, the design of the sampling voltage output by the acquisition module can be as follows: When the voltage of the precharge execution module is within a preset range, the output sampling voltage is a constant value to ensure that the sampling voltage is always greater than the reference voltage, thus ensuring that the bypass module is off and the precharge circuit performs precharge normally. At this time, the input and output of the sampling module are in a non-linear relationship. While ensuring that the output of the comparison module is low, the output voltage of the sampling module is limited to protect the input port of the comparison module. When the voltage of the precharge execution module exceeds the preset range, the output sampling voltage is a voltage divider value. The maximum value of this voltage divider is slightly greater than the reference voltage. At this time, the input and output of the sampling module are in a linear relationship. The reference voltage is within the voltage divider range. While ensuring that the voltage range in the linear region is as small as possible (while maximizing the input-output ratio in the linear region), it can better reflect the changes in the input voltage of the sampling module, resulting in higher accuracy and better control effect. As the voltage of the precharge execution module decreases continuously, the output voltage of the acquisition module also decreases continuously. When it is lower than the reference voltage, the comparison module controls the bypass module to turn on and stop precharge.

[0025] Among them, the voltage regulator module includes, but is not limited to, a voltage regulator circuit composed of Zener diodes, resistors and the like that can step down the power supply voltage. Through the design of the voltage regulator circuit, the external power supply voltage can be converted into a preset voltage value, which can be used as a reference voltage. This reference voltage is equivalent to the threshold used to stop the pre-charge state.

[0026] The sampling module includes, but is not limited to, a circuit composed of Zener diodes, resistors, etc., that can sample the voltage of the precharge execution module.

[0027] The comparison module includes, but is not limited to, comparators, operational amplifiers, and other circuits that can compare two voltages and output different comparison result signals.

[0028] The bypass module includes, but is not limited to, the use of switching circuits such as MOSFETs and relays to bypass the resistor of the precharge execution module and enable the precharge state to exit.

[0029] The precharge execution module includes, but is not limited to, resistors and other devices, which are used to implement the precharge function and limit the precharge current.

[0030] Based on the above implementation methods, refer to Figure 1 and Figure 2In this embodiment, an optional pre-charging process of the high-voltage pre-charging circuit is as follows: the target charging element is connected to the high-voltage pre-charging circuit, the external power supply powers the input terminal of the target charging element, the pre-charging execution module automatically connects to the target charging element, and the target charging element enters the pre-charging state; the voltage regulator module provides a reference voltage to the comparison module, and the sampling module provides the sampling voltage of the pre-charging execution module to the comparison module; when the sampling voltage is less than the reference voltage, the comparison module controls the bypass module to be turned on to bypass the pre-charging execution module, so that the external power supply stops pre-charging the target charging element; the pre-charging ends.

[0031] The high-voltage pre-charging circuit of this application embodiment achieves automatic control of pre-charging of the target charging element through the cooperation of a voltage stabilizing module, a sampling module, a comparison module, a bypass module and a pre-charging execution module. It does not require the integration of a single-chip microcomputer system, isolation modules and other modules into the module, thus eliminating the need for external control components. It has little impact on existing components and circuit designs, lower cost, high flexibility and is suitable for external pre-charging scenarios.

[0032] In one embodiment, reference Figure 3 An external power supply V1, a target charging element, and a pre-charge execution module 500 are connected in series to form a pre-charge circuit. Through this pre-charge circuit, the external power supply V1 can pre-charge the target charging element via the pre-charge execution module 500. Specifically, to facilitate the demonstration of the pre-charge circuit structure and functional effects, in one or more embodiments of this application, the target charging element is simplified to a target pre-charge capacitor C1, which can be understood as a target charging load. The pre-charge execution module 500 can be one or more resistors connected in series to limit the current of the target charging capacitor C1, thereby achieving safe pre-charge. It should be noted that this application does not impose specific limitations on the number and composition of resistors in the pre-charge execution module 500. However, to facilitate the demonstration of the structure and effects of each module, in one or more embodiments, one or more resistors connected in series are represented by a pre-charge resistor R6.

[0033] In one possible implementation, the voltage regulator module 100 includes a first resistor R1, a first Zener diode D1, a second resistor R2, and a third resistor R3. The first resistor R1 and the first Zener diode D1 are connected in series and in parallel across an external power supply V1. The second resistor R2 and the third resistor R3 are connected in series and in parallel across the first Zener diode D1. The connection node between the second resistor R2 and the third resistor R3 is configured to output a reference voltage to the comparator module 300. The external power supply V1 supplies power to the comparator module 300 through the first resistor R1 and the first Zener diode D1. With this voltage regulator module 100, a stable and adjustable reference voltage (low voltage) can be obtained from the unstable external power supply V1 (high voltage).

[0034] Specifically, when the circuit is operating normally, i.e., the voltage of the external power supply V1 is high enough that the current flowing through the first resistor R1 (limiting the current flowing through the first Zener diode D1 to prevent it from burning out due to excessive current) is sufficient to ensure that the first Zener diode D1 enters and maintains its voltage regulation region, the voltage across the first Zener diode D1 will be constantly "clamped" at its stable voltage Vz1. Therefore, the setting of the first Zener diode D1 can provide a stable reference voltage, i.e., the stable voltage Vz1, which determines the maximum possible value of the output voltage of the voltage regulation module 100. Since the second resistor R2 and the third resistor R3 are directly connected in parallel across the first Zener diode D1, the total voltage of their series circuit is equal to the voltage Vz1 across the first Zener diode D1. Therefore, the voltage V_out1 at the point where the voltage is output to the comparator module 300 is the voltage across the third resistor R3. According to the series voltage divider principle, V_out1 is equal to Vz1 multiplied by the proportion of the third resistor R3 in the total resistance (R2+R3). Therefore, under normal operation, V_out1 is a very stable DC voltage determined by the stable voltage Vz1 of the first Zener diode D1, and the ratio of the second resistor R2 and the third resistor R3. By changing the resistance ratio of the second resistor R2 and the third resistor R3, any desired stable voltage value, i.e., the reference voltage, can be obtained between 0V and the stable voltage Vz1. Furthermore, a capacitor C2 can be connected in parallel across the first Zener diode D1 to serve as a filter and voltage regulator.

[0035] In one possible implementation, the sampling module 200 includes a fourth resistor R4, a second Zener diode D2, and a fifth resistor R5; the fourth resistor R4 and the second Zener diode D2 are connected in series and in parallel with the precharge execution module 500; the fifth resistor R5 is connected in parallel across the second Zener diode D2 and in series with the fourth resistor R4; the connection node between the fourth resistor R4 and the second Zener diode D2 is configured to output a sampling voltage to the comparison module 300. With this configuration of the sampling module 200, a sampling voltage reflecting the precharge process can be obtained from the precharge execution module 500.

[0036] Specifically, in the sampling module 200, the voltage across the branch containing the second Zener diode D2 (the fourth resistor R4 and the second Zener diode D2 connected in series) is the same as the voltage across the precharge execution module 500 (equivalent to the voltage across the precharge resistor R6), V_R6. Therefore, the voltage of the precharge resistor R6 can be sampled. When V_R6 is within the regulated voltage range, the second Zener diode D2 is reverse-broken down and is in normal working condition. No matter how small the fluctuations of V_R6 are within this regulated voltage range (e.g., due to load or input changes), the second Zener diode D2 will absorb these changes by adjusting its own current, thereby ensuring that the voltage across it (i.e., the sampling voltage V_out2 output by the comparator module 300) remains constant at the breakdown voltage Vz2 of the second Zener diode D2. When V_R6 is too low (below the breakdown voltage Vz2 of the second Zener diode D2, or even if slightly higher than Vz2, the provided current is insufficient to bring it into the stable breakdown region), the second Zener diode D2 cannot break down. In this case, the second Zener diode D2 is equivalent to an extremely high resistor, or can be approximated as an open circuit. The original sampling module 200 circuit is simplified to a voltage divider circuit consisting of the fourth resistor R4 and the fifth resistor R5 connected in series, directly connected across the pre-charge resistor R6. The output point of the sampling voltage V_out2 is simplified to the connection point between the fourth resistor R4 and the fifth resistor R5. According to the voltage divider principle, the output voltage V_out2 is: V_out2 = V_R6 * [R5 / (R4 + R5)]. Therefore, when the input voltage V_R6 is below the regulated range, the output is no longer a constant Vz2, but a voltage divider value that varies with V_R6. The change in V_out2 reflects the changes in the pre-charge process. Based on the above implementation method, by adjusting the parameters of the first Zener diode D1, the second resistor R2, the third resistor R3, the second Zener diode D2, the fourth resistor R4, and the fifth resistor R5, the reference voltage value and the sampled voltage value after voltage division across the precharge resistor R6 can be adjusted, thereby achieving control of the precharge state.

[0037] In one possible implementation, the comparison module 300 includes a comparator U2; the non-inverting input of the comparator U2 is connected to the output of the voltage regulator module 100 and configured to receive a reference voltage; the inverting input of the comparator U2 is connected to the output of the sampling module 200 and configured to receive a sampled voltage; the comparator U2 is configured to output a low level to control the bypass module 400 to turn off when the sampled voltage is greater than the reference voltage; and to output a high level to control the bypass module 400 to turn on when the sampled voltage is less than the reference voltage. Specifically, comparator U2 outputs a low level when the input voltage at the inverting input terminal is greater than the input voltage at the non-inverting input terminal, and outputs a high level when the input voltage at the non-inverting input terminal is greater than the input voltage at the inverting input terminal. Therefore, by comparing the magnitude of the sampled voltage and the reference voltage, different output levels can be achieved, thereby controlling the conduction or cutoff of the bypass module 400. In this embodiment, the comparator U2 output type is push-pull output. If the applicable comparator output type is open-drain output, an additional external driving circuit is required. Also, since the voltage regulator has poor load-carrying capacity, a low-power model of comparator needs to be used here. In addition, if a stable output level of comparator U2 is required near the flip threshold, hardware hysteresis can be added to the circuit to reduce the repeated jumps in the output level of comparator U2 caused by the small voltage fluctuations at the inverting input terminal of the sampling circuit near the flip threshold (i.e., the reference voltage). Furthermore, the bypass module 400 uses an NMOS transistor U1, which is connected in parallel with the pre-charge resistor R6. The gate of NMOS transistor U1 is connected to the output of comparator U2. NMOS transistor U1 is turned on at a high level and turned off at a low level. Therefore, when the sampled voltage is greater than the reference voltage, comparator U2 outputs a low level, NMOS transistor U1 is off, and the external power supply V1 charges the target pre-charge capacitor C1 normally through the pre-charge resistor R6. When the sampled voltage is less than the reference voltage, comparator U2 outputs a high level, NMOS transistor U1 is turned on, short-circuiting the pre-charge resistor R6, thereby stopping the pre-charge. Furthermore, capacitor C3 can be connected in parallel between the gate and source of NMOS transistor U1 to provide filtering and voltage regulation.

[0038] Based on the above implementation methods, refer to Figure 3Another optional pre-charging process for the high-voltage pre-charging circuit in this embodiment is as follows: After the external power supply V1 is powered on, the external power supply V1 outputs an internal power supply voltage through the first current-limiting resistor R1 and the first Zener diode D1 in the voltage regulator module 100. This voltage is responsible for powering the comparator module 300. At the same time, this voltage generates a voltage reference source through the second resistor R2 and the third resistor R3, which are set by voltage division, as the reference voltage of the comparator module 300. Meanwhile, after the external power supply V1 is powered on, the external power supply V1 charges the target charging capacitor C1 through the pre-charging resistor R6 in the pre-charging execution module 500. During the charging process, the two resistors of the pre-charging resistor R6... The terminal voltage gradually decreases from the external power supply V1 to zero. Based on this, the voltage across the pre-charge resistor R6 is used to generate a sampling voltage through the current-limiting fourth resistor R4 in the sampling module 200 and the second Zener diode D2. When the voltage across the pre-charge resistor R6 is within the voltage regulation range of the voltage regulator circuit composed of the second Zener diode D2, the output of the sampling module 200 is a constant stable voltage of the second Zener diode D2. When the voltage across the pre-charge resistor R6 is lower than the voltage regulation range of the voltage regulator circuit composed of the second Zener diode D2, the output voltage of the sampling module 200 is the output voltage of the voltage divider circuit composed of the pre-charge resistor R6 through the fourth resistor R4 and the fifth resistor R5. The output voltage of the sampling module 200 serves as the input voltage of the comparison module 300. In the comparison module 300, the sampling voltage output by the sampling module 200 is compared with the reference voltage output by the voltage regulator module 100. If the sampling voltage output by the sampling module 200 is greater than the reference voltage, the comparator U2 outputs a low level, otherwise it outputs a high level. The high level output of the comparator U2 drives the NMOS transistor U1 in the bypass module 400 to conduct, short-circuiting the pre-charge resistor R6 of the pre-charge execution module 500, and the pre-charge ends.

[0039] To illustrate the pre-charging process and effect of the high-voltage pre-charging circuit in this application, circuit simulation was performed.

[0040] refer to Figure 4 Wherein, the external power supply V1 voltage is 200V, V(n001) is the voltage across the external power supply V1, V(n003) is the voltage across the pre-charge resistor R6, V(n002) is the internal power supply voltage output by the voltage regulator module 100, V(n006) is the comparison reference source (reference voltage) output by the voltage regulator module 100, V(n004) is the output voltage of the sampling module 200, and V(n005) is the gate-source voltage of the NMOS transistor U1 in the bypass module 400.

[0041] As shown in the figure, V(n003): After the external power supply V1 is powered on, the target pre-charge capacitor C1 is charged through the pre-charge resistor R6. The voltage across the pre-charge resistor R6 slowly decreases from 200V. After the pre-charge is completed, the voltage across the pre-charge resistor R6 becomes 0. V(n002): After the external power supply V1 is powered on, the voltage regulator module 100 starts to work. Due to the influence of capacitor C2, the voltage regulator module 100 outputs the internal power supply voltage with a certain rise time. V(n006): After the external power supply V1 is powered on, the voltage regulator module 100 starts to work. Since the internal power supply voltage output by the voltage regulator module 100 has a certain rise time, the comparison reference source derived from its voltage division has the same slope. V(n004): The voltage of the pre-charge resistor R6 decreases slowly from 200V. When it is within the voltage regulation range of the voltage regulation circuit composed of the second Zener diode D2, the output voltage of the sampling module 200 remains constant. When it is below the voltage regulation range of the voltage regulation circuit composed of the second Zener diode D2, the output voltage of the sampling module 200 is obtained by voltage division of the voltage across the pre-charge resistor R6 through the fourth resistor R4 and the fifth resistor R5, showing a gradual decreasing trend. V(n005): When the output voltage of the sampling module 200 is less than the reference voltage source output by the voltage regulator module 100, the output voltage of the comparison module 300 rises from zero to the internal power supply voltage, driving the NMOS transistor U1 of the bypass module 400 to turn on, bypassing the pre-charge resistor R6, and the pre-charge ends.

[0042] In summary, simulations show that all modules are operating normally and can achieve the expected pre-charge control effect.

[0043] In one embodiment, the high-voltage pre-charging circuit further includes an external expansion module, which is configured to connect to an external controller. The external controller is configured to obtain the pre-charging status of the high-voltage pre-charging circuit or to perform pre-charging control on the high-voltage pre-charging circuit through the external expansion module.

[0044] In one possible implementation, refer to Figure 5 A level conversion circuit is connected to the gate of NMOS transistor U1, and an external controller (microcontroller system) is connected through the level conversion circuit to realize the readback of the precharge state.

[0045] Specifically, the level conversion circuit includes power supply V2 (power supply V2 is a high-level voltage that the MCU can read), resistor R8, NMOS transistor M1, resistor R7, and NMOS transistor M2; the first end of resistor R8 is connected to the positive terminal of power supply V2, and the second end of resistor R8 is connected to the drain of NMOS transistor M2; the first end of resistor R7 is connected to the positive terminal of power supply V2, and the other end of resistor R7 is connected to the drain of NMOS transistor M1; the gate of NMOS transistor M2 is connected between resistor R7 and NMOS transistor M1; the sources of NMOS transistors M1 and M2 are connected and grounded. When comparator U2 outputs a high level, NMOS transistors U1 and M1 are turned on. At this time, the gate of NMOS transistor M2 is grounded through NMOS M1 and is in the off state. The MCU reads a high level, indicating that the pre-charge circuit has exited the pre-charge state. When comparator U2 outputs a low level, NMOS transistors U1 and M1 are turned off. Due to the off state of M1, the gate of NMOS transistor M2 receives a high level from power supply V2, turning on NMOS transistor M2. Power supply V2 is grounded through NMOS M2, and the MCU reads a low level, indicating that the pre-charge circuit is in the pre-charge stage. The level conversion circuit converts the high-voltage signal into a logic level that the MCU can recognize, realizing the pre-charge status readback.

[0046] In one possible implementation, refer to Figure 6 An external short-circuit module is connected between the gate and source of NMOS transistor U1, and an external controller (microcontroller system) is connected through the external short circuit to realize the external control of the pre-charge state.

[0047] Specifically, an NMOS transistor M1 is connected in parallel with the gate and source of NMOS transistor U1, and the gate of this NMOS transistor M1 is connected to the microcontroller system. The microcontroller uses an external signal to control the conduction or cutoff of NMOS transistor M1, thereby achieving active control of the precharge function. For example, after the microcontroller controls NMOS transistor M1 to conduct, the circuit can re-enter the precharge state for retrying in case of abnormal precharge state. At the same time, an NMOS transistor can be connected in parallel with ground at the inverting input of the comparator, and its gate is connected to the MCU. A high-level input will short-circuit the inverting input of the comparator to ground, and the comparator will output a high level, realizing the active cancellation of the precharge state, thereby achieving control of the precharge state.

[0048] Furthermore, this application provides a high-voltage pre-charging method based on the high-voltage pre-charging circuit described above; the method includes: When the power is turned on, the target charging element is pre-charged through the pre-charge execution module; During the pre-charging process, the voltage regulator module converts the input voltage from the power supply into a reference voltage and outputs it to the comparison module; the sampling module outputs a sampled voltage to the comparison module based on the voltage collected from the pre-charging execution module; the comparison module compares the sampled voltage with the reference voltage and controls the bypass module to turn on or off based on the comparison result. When the bypass module is turned on, the precharge execution module is bypassed, so that the external power supply stops precharging the target charging element.

[0049] Specifically, when the voltage of the pre-charge execution module acquired by the acquisition module is within a preset range, the output sampling voltage is a constant voltage value; when the voltage of the pre-charge execution module acquired by the acquisition module exceeds the preset range, the output sampling voltage is a voltage divider value. When the sampled voltage is greater than the reference voltage, the comparison module controls the bypass module to turn off; when the sampled voltage is less than the reference voltage, the comparison module controls the bypass module to turn on. Wherein, the constant voltage value is greater than the reference voltage, the input and output of the sampling module are in a non-linear relationship. At this time, while ensuring that the output of the comparison module is low, the output voltage of the sampling module is limited to protect the input port of the comparison module. The maximum value of the voltage divider is slightly greater than the reference voltage, at which time the input and output of the sampling module are in a linear relationship. The reference voltage is within the range of the voltage divider. While ensuring that the voltage range in the linear region is as small as possible (while maximizing the input-output ratio in the linear region), it can better reflect the changes in the input voltage of the sampling module, with higher accuracy and better control effect.

[0050] This high-voltage pre-charging method is based on the above-mentioned high-voltage pre-charging circuit. The specific process, principle and effect are described in the circuit implementation section above. Repeated parts will not be repeated.

[0051] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A high-voltage pre-charging circuit, characterized in that, The circuit includes a voltage regulator module, a sampling module, a comparison module, a bypass module, and a pre-charge execution module. An external power supply pre-charges the target charging element through the pre-charge execution module. The voltage regulator module is configured to convert the input voltage from an external power source into a reference voltage and output it to the comparator module; The sampling module is configured to output a sampling voltage to the comparison module based on the collected voltage of the precharge execution module; The comparison module is configured to compare the sampled voltage with the reference voltage and control the bypass module to turn on or off based on the comparison result. The bypass module is configured to bypass the precharge execution module after being turned on, so that the external power supply stops precharging the target charging element.

2. The high-voltage pre-charging circuit according to claim 1, characterized in that, The sampling module is further configured to output a constant voltage value when the voltage of the precharge execution module is within a preset range, and to output a voltage divider value when the voltage of the precharge execution module exceeds the preset range. The comparison module is further configured to control the bypass module to turn off when the sampled voltage is greater than the reference voltage, and to control the bypass module to turn on when the sampled voltage is less than the reference voltage. Wherein, the constant voltage value is greater than the reference voltage, and the reference voltage is within the range of the voltage divider.

3. The high-voltage pre-charging circuit according to claim 2, characterized in that, The voltage regulator module includes a first resistor, a first Zener diode, a second resistor, and a third resistor; The first resistor and the first Zener diode are connected in series and in parallel across the external power supply. The second resistor and the third resistor are connected in series and in parallel across the first Zener diode; the connection node between the second resistor and the third resistor is configured to output the reference voltage to the comparator module; An external power supply is configured to power the comparator module through the first resistor and the first Zener diode.

4. The high-voltage pre-charging circuit according to claim 2, characterized in that, The sampling module includes a fourth resistor, a second Zener diode, and a fifth resistor; The fourth resistor and the second Zener diode are connected in series and in parallel with the precharge execution module; The fifth resistor is connected in parallel across the second Zener diode and in series with the fourth resistor; The connection node between the fourth resistor and the second Zener diode is configured to output the sampled voltage to the comparison module.

5. The high-voltage pre-charging circuit according to any one of claims 2-4, characterized in that, The comparison module includes a comparator; the non-inverting input of the comparator is connected to the output of the voltage regulator module and configured to receive the reference voltage; the inverting input of the comparator is connected to the output of the sampling module and configured to receive the sampled voltage. The comparator is configured to output a low level to control the bypass module to shut down when the sampled voltage is greater than the reference voltage; When the sampling voltage is less than the reference voltage, a high level is output to control the bypass module to turn on.

6. The high-voltage pre-charging circuit according to claim 5, characterized in that, The bypass module includes an NMOS transistor, which is connected in parallel with the precharge execution module; the gate of the NMOS transistor is connected to the output of the comparator.

7. The high-voltage pre-charging circuit according to claim 1, characterized in that, The pre-charge execution module includes a pre-charge resistor, and an external power supply, a target charging element, and the pre-charge resistor are connected in series to form a pre-charge circuit.

8. The high-voltage pre-charging circuit according to claim 1, characterized in that, The high-voltage pre-charging circuit also includes an external expansion module, which is configured to connect to an external controller. The external controller is configured to obtain the pre-charging status of the high-voltage pre-charging circuit or to perform pre-charging control on the high-voltage pre-charging circuit through the external expansion module.

9. A high-voltage pre-charging method, characterized in that, Based on a high-voltage pre-charging circuit as described in any one of claims 1-8; the method includes: When the external power supply is turned on, the target charging element is pre-charged through the pre-charge execution module; During the pre-charging process, the voltage regulator module converts the input voltage from the external power supply into a reference voltage and outputs it to the comparison module; the sampling module outputs a sampled voltage to the comparison module based on the voltage collected from the pre-charging execution module; the comparison module compares the sampled voltage with the reference voltage and controls the bypass module to turn on or off based on the comparison result. When the bypass module is turned on, the precharge execution module is bypassed, so that the external power supply stops precharging the target charging element.

10. The high-voltage pre-charging method according to claim 9, characterized in that, The method further includes: When the voltage of the precharge execution module acquired by the acquisition module is within a preset range, the output sampling voltage is a constant voltage value; when the voltage of the precharge execution module acquired by the acquisition module exceeds the preset range, the output sampling voltage is a voltage divider value. When the sampled voltage is greater than the reference voltage, the comparison module controls the bypass module to turn off; when the sampled voltage is less than the reference voltage, the comparison module controls the bypass module to turn on. Wherein, the constant voltage value is greater than the reference voltage, and the reference voltage is within the range of the voltage divider.

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