WO2021128709A1

WO2021128709A1 - Slow-start circuit and slow-start control method thereof

Info

Publication number: WO2021128709A1
Application number: PCT/CN2020/091098
Authority: WO
Inventors: 陈功; 陈玉东; 王中鹤; 邹慧兴
Original assignee: 上海派能能源科技股份有限公司
Priority date: 2019-12-28
Filing date: 2020-05-19
Publication date: 2021-07-01

Abstract

Provided are a slow-start circuit and slow-start control method thereof; the slow-start circuit comprises a control module (1), a power supply module (2), a pre-charging branch line (3), and a main charging branch line (4); the control module (1) is used for outputting a pre-charging control signal and a main charging control signal; the pre-charging branch line (3) at least comprises an impedance element (5), the pre-charging branch line (3) being used for conducting to a load (6) a power signal outputted by the power module (2) in the pre-charging stage according to a received pre-charging control signal; the charging voltage value of the load (6) in the pre-charging stage is a set voltage value, the ratio of the set voltage value to the full voltage value of the power module (2) is greater than a set proportion, and the set proportion is less than 1; the main charging branch line (3) is used for conducting to the load (6) a power signal outputted by the power module (2) in the main charging stage according to a received main charging control signal; the load (6) is charged to the full voltage value of the power module (2) during the main charging phase. The described technical solution reduces the probability of a large inrush current generated by the main charging branch line (4).

Description

Slow start circuit and its slow start control method

Technical field

The embodiment of the present invention relates to the field of integrated circuit technology, in particular to a slow-start circuit and a slow-start control method thereof.

Background technique

BMS (Battery Management System) is the link between the battery and the user. The setting of BMS helps to improve the utilization of the battery, prevent the battery from overcharging or overdischarging, monitor the battery status and extend the battery life.

At present, in the field of low-voltage BMS, when the battery drives the load, such as inverters and other devices, it is unavoidable to generate a large instantaneous inrush current at the moment of power-on. This large instantaneous inrush current can easily burn the devices in the circuit. Cause the circuit to not work normally.

Summary of the invention

In view of this, the embodiments of the present invention provide a slow-start circuit and a slow-start control method thereof, which ensure that the power module is fully charged to the load while reducing the probability of a large inrush current generated by the main charging branch. This reduces the probability of damage to the components on the main charging branch and related paths.

In the first aspect, an embodiment of the present invention provides a slow-start circuit, including:

Control module, power supply module, pre-charging branch and main charging branch;

The control module is used to output a pre-charge control signal and a main charge control signal;

The pre-charging branch includes at least an impedance element, and the pre-charging branch is used to conduct the power signal output by the power module to the load in the pre-charging stage according to the received pre-charging control signal; The charging voltage value of the load in the pre-charging stage is a set voltage value, the ratio of the set voltage value to the full-charge voltage value of the power module is greater than the set ratio, and the set ratio is less than 1;

The main charging branch is used to conduct the power signal output by the power module to the load in the main charging phase according to the received main charging control signal; wherein, the load is charged in the main charging phase To the full voltage value of the power supply module.

Further, the first end of the pre-charging branch is short-circuited with the first end of the main charging branch and then electrically connected to the first power signal output end of the power module, and the first end of the pre-charging branch is electrically connected to the first power signal output end of the power module. The two ends are short-circuited with the second end of the main charging branch and then electrically connected to the first power input end of the load.

Further, the pre-charging branch further includes a first switch module configured to adjust the conduction time of the pre-charging branch according to the received pre-charging control signal.

Further, the first end of the impedance element serves as the first end of the precharge branch, the second end of the impedance element is electrically connected to the first end of the first switch module, and the first switch The control terminal of the module is connected to the precharge control signal, and the second terminal of the first switch module serves as the second terminal of the precharge branch; or,

The control terminal of the first switch module is connected to the precharge control signal, the first terminal of the first switch module serves as the first terminal of the precharge branch, and the second terminal of the first switch module It is electrically connected to the first end of the impedance element, and the second end of the impedance element serves as the second end of the precharge branch.

Further, the first power signal output terminal is the negative output terminal of the power module and the first switch module includes an NMOS tube; or, the first power signal output terminal is the positive output terminal of the power module And the first switch module includes a PMOS tube.

Further, the main charging branch includes a second switch module configured to adjust the on-time of the main charging branch according to the received main charging control signal.

Further, the control end of the second switch module is connected to the main charging control signal, the first end of the second switch module serves as the first end of the main charging branch, and the second switch module The second end serves as the second end of the main charging branch.

Further, the first power signal output terminal is the negative output terminal of the power module and the second switch module includes an NMOS tube; or, the first power signal output terminal is the positive output terminal of the power module And the second switch module includes a PMOS tube.

Further, the impedance element includes a thermosensitive impedance element, and the control module is used to detect the ambient temperature of the slow-start circuit and adjust the output precharge control signal according to the detected ambient temperature to adjust the temperature. State the on-time of the pre-charging branch;

Preferably, the control module includes:

A temperature detection sub-module for detecting the ambient temperature of the slow-start circuit and generating a temperature signal;

The control sub-module is configured to adjust the output pre-charge control signal according to the received temperature signal to adjust the conduction time of the pre-charge branch.

In the second aspect, an embodiment of the present invention also provides a slow-start control method of a slow-start circuit, including:

Control the pre-charging branch to conduct the power signal output by the power module to the load in the pre-charging stage; wherein the charging voltage value of the load in the pre-charging stage is the set voltage value, and the set voltage value is the same as the set voltage value. The ratio of the full-charge voltage value of the power module is greater than a set ratio, the set ratio is less than 1, and the pre-charging branch includes at least an impedance element;

The main charging branch is controlled to conduct the power signal output by the power supply module to the load during the main charging phase; wherein the load is charged to the full voltage value of the power supply module during the main charging phase.

The embodiment of the present invention provides a slow-start circuit and a slow-start control method thereof. The slow-start circuit is set to include a control module, a power module, a pre-charging branch, and a main charging branch. The control module is used to output a pre-charging control signal and a main charging branch. The charging control signal. The precharging branch includes at least an impedance element. The precharging branch is used to conduct the power signal output by the power module to the load in the precharging stage according to the received precharging control signal, and the load is charged in the precharging stage The voltage value is the set voltage value, the ratio of the set voltage value to the full-charge voltage value of the power module is greater than the set ratio, and the set ratio is less than 1. The main charging branch is used to charge in the main according to the received main charging control signal In the stage, the power signal output by the power module is turned on to the load, and the load is charged to the full voltage value of the power module in the main charging stage. In this way, the pre-charging branch containing the impedance element is used to buffer the voltage at both ends of the load to the set voltage For example, the set voltage value can be about 70% of the full voltage value of the power module, and then use the main charging branch to charge the remaining 30% of the power module to the load, ensuring that the power module is fully charged to the load. At the same time of charging, the charging voltage corresponding to the main charging branch is greatly reduced, which reduces the probability of a large inrush current generated by the main charging branch, thereby reducing the probability of damage to the main charging branch and the devices on the related path. .

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present invention or the background art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the background art. Obviously, the drawings in the following description are of the present invention. For the schematic diagrams of some embodiments of the invention, for those of ordinary skill in the art, other solutions can be obtained based on the drawings without creative work.

FIG. 1 is a schematic structural diagram of a slow-start circuit provided by an embodiment of the present invention;

2 is a schematic diagram of a specific circuit structure of a slow-start circuit provided by an embodiment of the present invention;

3 is a schematic diagram of a specific circuit structure of another slow-start circuit provided by an embodiment of the present invention;

4 is a schematic diagram of a specific circuit structure of another slow-start circuit provided by an embodiment of the present invention;

5 is a schematic diagram of a specific circuit structure of another slow-start circuit provided by an embodiment of the present invention;

FIG. 6 is a schematic flowchart of a slow start control method provided by an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for ease of description, the drawings only show a part of the structure related to the present invention, but not all of the structure. Throughout this specification, the same or similar reference numerals represent the same or similar structures, elements or processes. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other if there is no conflict.

FIG. 1 is a schematic structural diagram of a slow-start circuit provided by an embodiment of the present invention. As shown in Figure 1, the slow-start circuit includes a control module 1, a power supply module 2, and a pre-charging branch 3. The control module 1 is used to output a pre-charging control signal. The pre-charging branch 3 includes at least an impedance element 5. The pre-charging branch 3 is used to conduct the power signal output by the power module 2 to the load 6 in the pre-charging stage according to the received pre-charging control signal. The charging voltage value of the load 6 in the pre-charging stage is the set voltage value, and the set voltage value is equal to The ratio of the full voltage value of the power module 2 is greater than the set ratio, and the set ratio is less than 1.

Specifically, as shown in Fig. 1, in the initial charging stage, that is, the pre-charging stage, the control module 1 outputs a pre-charging control signal that can control the pre-charging branch 3 to turn on, and the pre-charging branch 3 receives the pre-charging control signal. The signal is turned on, and the power module 2 charges the load 6 through the pre-charging branch 3. The charging voltage value of the load 6 in the pre-charging stage can be set to the set voltage value, and the set voltage value is the full charge of the power module 2. The ratio of the voltage value is greater than the set ratio. For example, if the set ratio is set to 67%, during the pre-charging phase, the power module 2 charges the voltage across the load 6 to 67% of the full-charge voltage of the power module 2 through the pre-charging branch 3 That is to stop, because the impedance element 5 is provided in the pre-charging branch 3, during the pre-charging stage, the resistance of the impedance element 5 can be adjusted so that no excessive current is generated on the pre-charging branch 3. The pre-charging process Able to proceed slowly.

The control module 1 is also used to output a main charging control signal, and the slow-start circuit also includes a main charging branch 4, which is used to output the power signal from the power supply module 2 in the main charging stage according to the received main charging control signal It is turned on to the load 6, and the load 6 is charged to the full voltage value of the power module 2 during the main charging phase.

Specifically, as shown in Figure 1, during the pre-charging phase, the control module 1 outputs a main charging control signal that can control the main charging branch 4 to disconnect. The main charging branch 4 is not turned on during the pre-charging phase, and the power module 2 only The load 6 is charged through the pre-charging branch 3. After entering the main charging stage, you can set the control module 1 to output a precharge control signal that can control the disconnection of the precharge branch 3, and output a main charging control signal that can control the main charging branch 4 to turn on, or set the control module 1 to output The precharge control signal that controls the conduction of the precharge branch 3, and outputs the main charge control signal that can control the conduction of the main charging branch 4, because the impedance element 5 is provided in the precharge branch 3, no matter entering the main charging stage, the precharge Whether the charging branch 3 is turned on, the charging current will not flow through the pre-charging branch 3, that is, at this stage, the power module 2 charges the load 6 through the main charging branch 4, and the power module 2 transfers the load to the load through the main charging branch 4. The voltage at both ends of 6 is charged to the full voltage of the power supply module 2.

In this way, the pre-charge branch 3 including the impedance element 5 is used to buffer the voltage across the load 6 to a set voltage value. The set voltage value can be, for example, about 70% of the full-charge voltage value of the power module 2, and then use the main The charging branch 4 charges the remaining 30% of the voltage of the power module 2 to the load 6. While ensuring that the power module 2 is fully charged to the load 6, the charging voltage corresponding to the main charging branch 4 that needs to be charged is greatly reduced. This prevents the main charging branch 4 from generating a large inrush current, thereby reducing the probability of damage to the main charging branch 4 and the components on the related paths.

Optionally, as shown in Figure 1, the first terminal A1 of the pre-charging branch 3 is short-circuited with the first terminal B1 of the main charging branch 4 and then electrically connected to the first power signal output terminal V1 of the power module 2. The second terminal A2 of the charging branch 3 is short-circuited with the second terminal B2 of the main charging branch 4 and then electrically connected to the first power input terminal V10 of the load 6.

Specifically, in the pre-charging phase, the power module 2 charges the load 6 through the pre-charging branch 3, and in the main charging phase, the power module 2 charges the load 6 through the main charging branch 4, and the pre-charging branch 3 can be set. In parallel with the main charging branch 4, the pre-charging control signal and the main charging control signal output by the control module 1 respectively control the on-off of the pre-charging branch 3 and the main charging branch 4, so as to realize the use of different branches in the corresponding stage The power module 2 can charge the load 6. In order to realize the parallel connection between the pre-charging branch 3 and the main charging branch 4, the first terminal A1 of the pre-charging branch 3 and the first terminal B1 of the main charging branch 4 can be short-circuited with the first power signal of the power module 2 The output terminal V1 is electrically connected, and the second terminal A2 of the pre-charging branch 3 is short-circuited with the second terminal B2 of the main charging branch 4 and then electrically connected to the first power input terminal V10 of the load 6.

FIG. 2 is a schematic diagram of a specific circuit structure of a slow-start circuit provided by an embodiment of the present invention. 1 and 2, it can be set that the pre-charging branch 3 further includes a first switch module 7 for adjusting the conduction time of the pre-charging branch 3 according to the received pre-charging control signal.

Specifically, the pre-charging branch 3 needs to be turned on during the pre-charging phase to realize that the power module 2 charges the load 6 through the pre-charging branch 3, and the pre-charging branch 3 can be turned on or off during the main charging phase. The power module 2 charges the load 6 through the main charging branch 4, and the pre-charging branch 3 is set to include an impedance element 5 and a first switch module 7. The impedance element 5 is used to realize the pre-charging stage. The power module 2 passes through the pre-charging branch 3. While slowly charging the load 6, the first switch module 7 adjusts the conduction time of the pre-charge branch 3 according to the received pre-charge control signal, and the first switch module 7 can be used to control the pre-charge branch 3 at least in the pre-charge period. The charging phase is turned on.

Optionally, in conjunction with FIGS. 1 and 2, the first end of the impedance element 5 can be set as the first end A1 of the precharge branch, and the second end of the impedance element 5 is electrically connected to the first end of the first switch module 7. , The control terminal of the first switch module 7 is connected to the precharge control signal, and the second terminal of the first switch module 7 serves as the second terminal A2 of the precharge branch. Specifically, the first end of the impedance element 5 is set as the first end A1 of the precharge branch, the second end of the impedance element 5 is electrically connected to the first end of the first switch module 7, and the control end of the first switch module 7 Access to the pre-charge control signal, the second end of the first switch module 7 is used as the second end A2 of the pre-charge branch, which realizes that the impedance element 5 and the first switch module 7 are connected in series, and the impedance element 5 can be used to realize the pre-charge stage. While the power module 2 slowly charges the load 6 through the pre-charging branch 3, the first switch module 7 is used to control the pre-charging branch 3 to be turned on at least during the pre-charging phase.

FIG. 3 is a schematic diagram of a specific circuit structure of another slow-start circuit provided by an embodiment of the present invention. Different from the slow-start circuit of the structure shown in FIG. 2, the slow-start circuit of the structure shown in FIG. 3 sets the control terminal of the first switch module 7 to access the precharge control signal, and the first terminal of the first switch module 7 serves as the precharge control signal. The first end A1 of the charging branch, the second end of the first switch module 7 and the first end of the impedance element 5 are electrically connected, and the second end of the impedance element 5 is used as the second end A2 of the pre-charging branch. The impedance element 5 is connected in series with the first switch module 7, so that while the impedance element 5 is used to realize the pre-charging stage, the power module 2 slowly charges the load 6 through the pre-charging branch 3, and the first switch module 7 is used to control the pre-charging branch. 3 Turn on at least during the precharge phase.

Optionally, in conjunction with Figures 1 to 3, the first power signal output terminal V1 can be set as the negative output terminal of the power supply module 2. The first switch module 7 includes an NMOS tube, and the control module 1 can be set to output high during the precharging phase. A pre-charge control signal of a high level to control the first switch module 7 to be turned on during the pre-charge stage, and the power module 2 charges the load 6 through the pre-charge branch 3.

Optionally, as shown in FIG. 1, the main charging branch 4 includes a second switch module 8 configured to adjust the conduction time of the main charging branch 4 according to the received main charging control signal. Specifically, the control module 1 outputs the main charging control signal, and the second switch module 8 can adjust the conduction of the main charging branch 4 according to the received main charging control signal to ensure that the main charging branch 4 is turned off during the pre-charging phase. , Turn on during the main charging phase.

The conduction state of the second switch module 8 in the main charging branch 4 can be controlled, that is, the semi-conduction characteristics of the second switch module 8 can be used to control the current flowing through the main charging branch 4, that is, the second switch module 8 can be controlled. It is in an intermediate state between fully turned on and fully turned off to avoid a large inrush current that affects the normal operation of the main charging branch 4 and the components on the related branch. However, when the second control module 1 is in the intermediate state between fully turned on and fully turned off, the equivalent resistance of the second switch module 8 is relatively large, resulting in relatively large power consumption of the second switch module 8 and easy damage to the first switch module 8. The second switch module 8. In addition, the equivalent resistance of the second switch module 8 is relatively large. When the equivalent capacitance of the load 6 supplied by the power module 2 is relatively large, the charging time is equal to the product of the aforementioned equivalent resistance and equivalent capacitance. That will cause the second switch module 8 to work in a semi-conductive state for a long time, and also increase the probability of the second switch module 8 being damaged, which affects the charging process of the power module 2 to the load 6.

In the embodiment of the present invention, the pre-charge branch 3 including the impedance element 5 is used to buffer the voltage across the load 6 to a set voltage value. The set voltage value may be, for example, about 70% of the full-charge voltage value of the power module 2. Use the main charging branch 4 to charge the remaining 30% of the voltage of the power module 2 to the load 6. While ensuring that the power module 2 is fully charged to the load 6, the main charging branch 4 corresponds to the charging voltage that needs to be charged. It can be greatly reduced. The main charging branch 4 can be set to be fully turned on, that is, the second switch module 8 is controlled to be in a fully conductive module, and the equivalent resistance of the second switch module 8 is reduced, which prevents the main charging branch 4 from generating a relatively high value. The large inrush current reduces the probability of damage to the main charging branch 4 and related components, and at the same time solves the problem of the large power consumption of the second switch module 8 caused by the excessive equivalent resistance of the second switch module 8. , The second switch module 8 is easily damaged. When the equivalent capacitance of the load 6 supplied by the power module 2 is large, the second switch module 8 will work in a semi-conductive state for a long time, and the probability of the second switch module 8 being damaged increases. A problem that affects the charging process of the power supply module 2 to the load 6.

Optionally, in conjunction with Figures 1 to 3, the control terminal of the second switch module 8 can be set to access the main charging control signal, and the first terminal of the second switch module 8 serves as the first terminal B1 of the main charging branch, and the second The second end of the switch module 8 is used as the second end B2 of the main charging branch, and the main charging control signal output by the control module 1 is adjusted to adjust the conduction state of the second switch module 8 to ensure that the main charging stage is second. The switch module 8 is turned on, that is, the main charging branch 4 is turned on, and the power module 2 charges the load 6 through the main charging branch 4.

Optionally, in conjunction with Figures 1 to 3, the first power signal output terminal V1 can be set as the negative output terminal of the power supply module 2, and the second switch module 8 includes an NMOS tube, and the control module 1 can be set to output low during the precharging phase. Level of the pre-charge control signal to control the second switch module 8 to turn off during the pre-charge stage, and the control module 1 is set to output a high-level pre-charge control signal during the main charging stage to control the second switch module 8 in the main charging stage. When the phase is turned on, the power module 2 charges the load 6 through the main charging branch 4.

FIG. 4 is a schematic diagram of a specific circuit structure of another slow-start circuit provided by an embodiment of the present invention. Different from the slow-start circuit of the structure shown in Figs. 1 to 3, the slow-start circuit of the structure shown in Fig. 4 sets the first power signal output terminal V1 as the positive output terminal of the power module 2, and the first switch module 7 and the second The two switch modules 8 both include PMOS transistors and can be set in the pre-charge stage. The control module 1 outputs a low-level pre-charge control signal and a high-level main charge control signal to control the pre-charge branch 3 to be turned on. The main charging branch 4 is turned off, and the power module 2 charges the load 6 through the pre-charging branch 3. In the main charging phase, the control module 1 outputs a low-level or high-level pre-charge control signal, and outputs a low-level main charging control signal to control the main charging branch 4 to be turned on, and the power module 2 passes through the main charging branch 4 Charge the load 6.

As shown in FIG. 4, the first end of the impedance element 5 can be set as the first end A1 of the precharging branch, and the second end of the impedance element 5 is electrically connected to the first end of the first switch module 7, and the first switch module The control terminal of 7 is connected to the pre-charge control signal, and the second terminal of the first switch module 7 is used as the second terminal A2 of the pre-charge branch, that is, the impedance element 5 is set in series with the first switch module 7, which can also be as shown in Figure 5. As shown, the control terminal of the first switch module 7 is set to access the precharge control signal, the first terminal of the first switch module 7 is used as the first terminal A1 of the precharge branch, and the second terminal of the first switch module 7 is connected to the impedance element The first end of the impedance element 5 is electrically connected, and the second end of the impedance element 5 is used as the second end A2 of the pre-charging branch, so that the impedance element 5 is connected in series with the first switch module 7, and the impedance element 5 can be used to realize the pre-charging stage power supply. While the module 2 slowly charges the load 6 through the pre-charging branch 3, the first switch module 7 is used to control the pre-charging branch 3 to be turned on at least during the pre-charging phase.

Optionally, in conjunction with FIGS. 1 to 5, the impedance element 5 can be set to include a thermal impedance element 5. The control module 1 is used to detect the ambient temperature of the slow-start circuit and adjust the output precharge control signal according to the detected ambient temperature. To adjust the conduction time of the pre-charging branch 3, for example, the thermistor element 5 can be set to NTC (Negative Temperature Coefficient, negative temperature coefficient thermistor).

You can set the resistance of the impedance element 5 under normal temperature conditions to R, and the equivalent capacitance of the load 6 to C. In addition, you can set the voltage at both ends of the load 6 to be fully charged to the full power module 2 after t0=R*C under normal temperature conditions. 67% of the electrical voltage, that is, to charge the voltage across the load 6 to 67% of the full-charge voltage of the power module 2 under normal temperature conditions, the pre-charging phase time to pass is t0. However, the ambient temperature where the slow-start circuit is located is constantly changing. Since the impedance element 5 is a thermally sensitive impedance element 5, changes in the ambient temperature will also cause the resistance of the impedance element 5 to change.

When the ambient temperature is lower than normal temperature, taking the impedance element 5 as an NTC element as an example, the resistance value of the impedance element 5 is greater than R, and the time required to charge the voltage across the load 6 to 67% of the full voltage of the power module 2 is obvious If the time of the pre-charging phase is still set according to t0 at room temperature, the voltage across the load 6 will not reach 67% of the full-charge voltage of the power supply after the pre-charging phase is over, resulting in the remaining need to pass through the main charging support The charging voltage of circuit 4 is larger, which increases the probability of a larger inrush current in the main charging stage when the power module 2 charges the load 6 through the main charging branch 4, and increases the main charging branch 4 and related branches. The probability of the device being damaged.

When the ambient temperature is higher than normal temperature, taking the impedance element 5 as an NTC element as an example, the resistance value of the impedance element 5 is less than R, and the time required to charge the voltage across the load 6 to 67% of the full voltage of the power module 2 is obvious Decrease, if the time of the pre-charging phase is still set according to t0 at normal temperature, it will cause the voltage across the load 6 to exceed 67% of the full-charge voltage of the power supply after the pre-charging phase is over, which may cause impedance element 5, such as NTC The component is overheated and burned, which affects the pre-charging process of the slow-start circuit.

In the embodiment of the present invention, the control module 1 is configured to detect the ambient temperature of the slow-start circuit, and adjust the output precharge control signal according to the detected ambient temperature to adjust the conduction time of the precharge branch 3. Exemplarily, it can be set that when the ambient temperature of the slow-start circuit is increased and the resistance of the impedance element 5 is less than R, the control module 1 can detect that the ambient temperature of the slow-start circuit has increased, and adjust the output precharge The control signal is used to reduce the time of the pre-charging stage. For example, the control module 1 can adjust the pre-charging control signal to reduce the turn-on time of the first switch module 7. With reference to the above description of the ambient temperature being higher than normal temperature, by reducing the pre-charging The period of time can effectively reduce the probability of NTC components overheating and burning. Exemplarily, it can be set that when the ambient temperature of the slow-start circuit is reduced and the resistance of the impedance element 5 is greater than R, the control module 1 can detect that the ambient temperature of the slow-start circuit has decreased, and adjust the output precharge control signal In order to increase the time of the pre-charging phase, for example, the control module 1 can adjust the time that the first switch module 7 is turned on by adjusting the pre-charging control signal. This effectively reduces the probability of a large inrush current generated during the main charging phase of the power module 2 charging the load 6 through the main charging branch 4, and reduces the probability that the main charging branch 4 and the components on the related branch are damaged.

With reference to the above description, the time T of the precharge phase adjusted according to the ambient temperature satisfies the following formula:

T=K·t0

Among them, K is equal to the ratio of Rt to R, RT is the resistance of the NTC element after temperature change, and Rt satisfies the following calculation formula:

Among them, Rt is the resistance value of the NTC element at the temperature T1, T0 is the normal temperature, both are Kelvin temperatures, and B is the material constant of the NTC element.

In this way, the T calculated according to the above formula enables the control module 1 to adjust the time of the corresponding pre-charging phase, so as to effectively reduce the probability of the NTC element being burned out due to overheating, and reduce the main power module 2 charging the load 6 through the main charging branch 4 The probability of a large inrush current during the charging phase reduces the probability of damage to the main charging branch 4 and the components on the related branch.

Optionally, in conjunction with Figures 1 to 5, the control module 1 can be configured to include a temperature detection submodule 11 and a control submodule 12. The temperature detection submodule 11 is used to detect the ambient temperature of the slow-start circuit and generate a temperature signal, and the control submodule 12 It is used to adjust the output pre-charge control signal according to the received temperature signal to adjust the conduction time of the pre-charge branch 3. The temperature detection sub-module 11 may include, for example, temperature sensing devices such as a temperature sensor, using the temperature detection sub-module 11 and control The sub-module 12 realizes that the control module 1 adjusts the time of the pre-charging phase according to the temperature of the slow-start circuit, thereby reducing the probability that the NTC element is overheated and burned out, and reducing the main charging phase when the power module 2 charges the load 6 through the main charging branch 4 The probability of a larger inrush current reduces the probability of damage to the components on the main charging branch 4 and related branches.

It should be noted that the 67% and 70% in the above embodiment are only exemplary values of the set ratio, and do not represent a limitation on the set ratio. The specific characteristics of the devices in the main charging branch 4 in the slow-start circuit can be used for comparison. Set the ratio and set it.

The embodiment of the present invention also provides a slow-start control method of a slow-start circuit, which can be executed by the slow-start circuit of the above embodiment. FIG. 6 is a schematic flowchart of a slow-start control method provided by an embodiment of the present invention, as shown in FIG. As shown in 6, the slow-start control method of the slow-start circuit includes:

S110. Control the pre-charging branch to conduct the power signal output by the power module to the load in the pre-charging stage; wherein the charging voltage value of the load in the pre-charging stage is the set voltage value, and the set voltage value is the full power of the power module The ratio of the voltage value is greater than the set ratio, and the set ratio is less than 1, and the precharge branch includes at least an impedance element.

1 to 5, in the initial charging stage, that is, the pre-charge stage, the control module 1 outputs a pre-charge control signal that can control the pre-charge branch 3 to turn on, and the pre-charge branch 3 receives the pre-charge control signal The power module 2 charges the load 6 through the pre-charging branch 3. The charging voltage value of the load 6 in the pre-charging stage can be set to the set voltage value, and the set voltage value is the full voltage of the power module 2. The value ratio is greater than the set ratio, and the set ratio is less than 1. For example, if the set ratio is 67%, during the pre-charging phase, the power module 2 charges the voltage across the load 6 through the pre-charging branch 3 until the power module 2 is full 67% of the electric voltage stops. Because the impedance element 5 is provided in the pre-charging branch 3, the resistance value of the impedance element 5 can be adjusted during the pre-charging stage so that no excessive current is generated on the pre-charging branch 3 , The pre-charging process can proceed slowly.

S120. Control the main charging branch to conduct the power signal output by the power module to the load during the main charging phase; wherein the load is charged to the full voltage value of the power module during the main charging phase.

1 to 5, in the pre-charging phase, the control module 1 outputs a main charging control signal that can control the main charging branch 4 to disconnect. The main charging branch 4 is not turned on during the pre-charging phase, and the power module 2 only passes through the pre-charging phase. The charging branch 3 charges the load 6. After entering the main charging stage, you can set the control module 1 to output a precharge control signal that can control the disconnection of the precharge branch 3, and output a main charging control signal that can control the main charging branch 4 to turn on, or set the control module 1 to output The precharge control signal that controls the conduction of the precharge branch 3, and outputs the main charge control signal that can control the conduction of the main charging branch 4, because the impedance element 5 is provided in the precharge branch 3, no matter entering the main charging stage, the precharge Whether the charging branch is turned on, the charging circuit will not flow through the pre-charging branch 3, that is, at this stage, the power module 2 charges the load 6 through the main charging branch 4, and the power module 2 is blocked by the main charging branch 4 The voltage at both ends is charged to the full voltage of the power module 2.

In the embodiment of the present invention, the pre-charge branch 3 including the impedance element 5 is used to buffer the voltage across the load 6 to a set voltage value. The set voltage value may be, for example, about 70% of the full-charge voltage value of the power module 2. Use the main charging branch 4 to charge the remaining 30% of the voltage of the power module 2 to the load 6. While ensuring that the power module 2 is fully charged to the load 6, the main charging branch 4 corresponds to the charging voltage that needs to be charged. This greatly reduces and prevents the main charging branch 4 from generating a large inrush current, thereby reducing the probability of damage to the main charging branch 4 and the components on the related paths.

Note that the above are only the preferred embodiments of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and various obvious changes, readjustments and substitutions can be made to those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention. The scope of is determined by the scope of the appended claims.

Claims

A slow-start circuit is characterized in that it comprises:

Control module, power supply module, pre-charging branch and main charging branch;

The control module is used to output a pre-charge control signal and a main charge control signal;

The pre-charging branch includes at least an impedance element, and the pre-charging branch is used to conduct the power signal output by the power module to the load in the pre-charging stage according to the received pre-charging control signal; The charging voltage value of the load in the pre-charging stage is a set voltage value, the ratio of the set voltage value to the full-charge voltage value of the power module is greater than the set ratio, and the set ratio is less than 1;

The main charging branch is used to conduct the power signal output by the power module to the load in the main charging phase according to the received main charging control signal; wherein, the load is charged in the main charging phase To the full voltage value of the power supply module.
The slow-start circuit according to claim 1, wherein the first end of the pre-charging branch is short-circuited with the first end of the main charging branch and then is connected to the first power signal output of the power module The second end of the pre-charging branch is electrically connected to the second end of the main charging branch and then is electrically connected to the first power input end of the load.
The slow-start circuit according to claim 2, wherein the pre-charge branch further comprises a first switch module, and the first switch module is used to adjust the pre-charge control signal according to the received pre-charge control signal. The on-time of the charging branch.
The slow-start circuit according to claim 3, wherein the first end of the impedance element serves as the first end of the precharge branch, and the second end of the impedance element is connected to the first switch module. The first terminal of the first switch module is electrically connected, the control terminal of the first switch module is connected to the precharge control signal, and the second terminal of the first switch module serves as the second terminal of the precharge branch; or,

The control terminal of the first switch module is connected to the precharge control signal, the first terminal of the first switch module serves as the first terminal of the precharge branch, and the second terminal of the first switch module It is electrically connected to the first end of the impedance element, and the second end of the impedance element serves as the second end of the precharge branch.
The slow-start circuit according to claim 3 or 4, wherein the first power supply signal output terminal is the negative output terminal of the power supply module and the first switch module includes an NMOS transistor; or, the first power supply signal output terminal is a negative output terminal of the power supply module. A power signal output terminal is the positive output terminal of the power module and the first switch module includes a PMOS tube.
The slow-start circuit according to claim 2, wherein the main charging branch includes a second switch module, and the second switch module is used to adjust the main charging according to the received main charging control signal. The on-time of the branch.
The slow-start circuit according to claim 6, wherein the control terminal of the second switch module is connected to the main charging control signal, and the first terminal of the second switch module serves as the main charging branch The first end of the second switch module is used as the second end of the main charging branch.
The slow-start circuit according to claim 6 or 7, wherein the first power supply signal output terminal is the negative output terminal of the power supply module and the second switch module includes an NMOS transistor; or, the first power supply signal output terminal is a negative output terminal of the power supply module. A power signal output terminal is the positive output terminal of the power module and the second switch module includes a PMOS tube.
The slow-start circuit according to claim 1, wherein the impedance element comprises a thermal impedance element, and the control module is used to detect the ambient temperature of the slow-start circuit and based on the detected ambient temperature Adjusting the output pre-charging control signal to adjust the on-time of the pre-charging branch;

Preferably, the control module includes:

The temperature detection sub-module is used to detect the ambient temperature of the slow-start circuit and generate a temperature signal;

The control sub-module is configured to adjust the output pre-charge control signal according to the received temperature signal to adjust the conduction time of the pre-charge branch.
A slow-start control method of a slow-start circuit is characterized in that it comprises:

The pre-charging branch is controlled to conduct the power signal output by the power module to the load in the pre-charging stage; wherein the charging voltage value of the load in the pre-charging stage is the set voltage value, and the set voltage value is the same as the set voltage value. The ratio of the full-charge voltage value of the power module is greater than a set ratio, the set ratio is less than 1, and the pre-charging branch includes at least an impedance element;

The main charging branch is controlled to conduct the power signal output by the power supply module to the load during the main charging phase; wherein the load is charged to the full voltage value of the power supply module during the main charging phase.