A drive control circuit, its control method, medium, and switching circuit.

Abstract

This invention relates to a drive control circuit, its control method, medium, and switching circuit. The control method includes: controlling a power switch to start in an adaptive starting current identification mode; monitoring the starting current of the power switch; determining whether the starting current is within a preset range; and if not, adjusting the resistance of a digital potentiometer to bring the starting current within the preset range. This invention enables the automatic adjustment of the conduction speed of the power devices in the switching circuit based on the state of the downstream power circuit, thereby controlling the circuit's starting current and ensuring safe circuit startup.

Description

Technical Field

[0001] This invention belongs to the field of drive control technology, and particularly relates to a drive control circuit and its control method, medium and switching circuit. Background Technology

[0002] In industrial applications, power devices such as IGBTs or MOSFETs are typically used to form switching circuits to provide power to the circuitry. In conventional applications, the parameters of the circuits surrounding the switching circuit are fixed, and the conduction speed of the power devices is also fixed. Furthermore, the downstream circuitry is generally a capacitive load, meaning that the faster the voltage rises at power-on, the larger the starting current. This can generate a large inrush current at the moment the switching circuit turns on. While this may not cause immediate damage during a few startup cycles, prolonged exposure to high current surges can lead to irreversible damage to the controller. Summary of the Invention

[0003] In view of this, the present invention provides a drive control circuit and its control method, medium and switching circuit to solve the problem of overshoot in the starting current of power devices.

[0004] To address the aforementioned technical problems, the first aspect of the present invention provides a drive control circuit, which includes a power switch and a controller for controlling its startup or shutdown. The drive control circuit further includes:

[0005] A controllable resistor and a digital potentiometer are connected in series between the controller and the gate of the power switch. The controllable resistor is used to adjust the gate drive resistance of the power switch.

[0006] The current detection module is connected to the drain of the power switch and is used to collect the starting current of the power switch.

[0007] The controller is configured to adjust the resistance of the controllable resistor based on the startup current in order to determine the target value of the gate drive resistor.

[0008] Alternatively, the controllable resistor can be a digital potentiometer.

[0009] A second aspect of the present invention provides a control method for a drive control circuit of the first aspect, wherein the drive control circuit is provided with a start-up current adaptive identification mode, and the control method includes:

[0010] In the adaptive startup current identification mode, the power switch is controlled to start up;

[0011] Monitor the starting current of the power switch;

[0012] Determine whether the starting current is within the preset range;

[0013] If not, adjust the resistance of the controllable resistor to keep the starting current within the preset range.

[0014] Further, optionally, the resistance value of the controllable resistor is adjusted to keep the starting current within a preset range, including:

[0015] Control the power switch to turn it off;

[0016] When the starting current exceeds the upper limit of the preset range, the resistance value of the controllable resistor is increased;

[0017] When the starting current is less than the lower limit of the preset range, the resistance value of the controllable resistor is reduced.

[0018] Further, optionally, the resistance value of the controllable resistor can be increased or decreased, including:

[0019] The corresponding adjustment value is determined based on the difference between the starting current and the upper or lower limit value;

[0020] The resistance value of the controllable resistor can be increased or decreased according to the corresponding adjustment value.

[0021] Further optionally, determining the corresponding adjustment value based on the difference between the starting current and the upper or lower limit includes: dividing the difference into multiple intervals, each interval corresponding to an adjustment value; after calculating the difference, determining the interval of the difference, thereby determining the corresponding adjustment value.

[0022] Further optionally, after increasing or decreasing the resistance value of the controllable resistor, the control method further includes:

[0023] The process then transitions to the power switch control to initiate the start-up process, proceeding to the next current detection cycle until the starting current is determined to be within the preset range.

[0024] Further optionally, when the starting current is determined to be within a preset range, the control method further includes:

[0025] Save the current resistance value and exit the startup current adaptive identification mode.

[0026] Further optionally, before the power switch is activated, the control method further includes:

[0027] Adjust the resistance of the controllable resistor to the preset value.

[0028] A third aspect of the present invention provides a non-transitory computer-readable storage medium having program instructions stored thereon, wherein when the program instructions are executed by one or more processors, the one or more processors are used to implement the control method of any of the second aspects.

[0029] The fourth aspect of the present invention provides a switching circuit that employs the drive control circuit of the first aspect, or the control method of any one of the second aspects, or has a non-transitory computer-readable storage medium of the third aspect.

[0030] By adopting the above technical solution, the present invention has the following beneficial effects:

[0031] This invention can automatically adjust the conduction speed of the power devices in the switching circuit according to the state of the downstream power circuit, so as to control the circuit startup current and ensure the safe startup of the circuit.

[0032] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0033] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0034] Figure 1 This is a topology diagram of a drive control circuit according to an embodiment of the present invention.

[0035] Figure 2 This is a flowchart illustrating a control method for a drive control circuit according to an embodiment of the present invention.

[0036] Figure 3 This is a flowchart illustrating a control method for a drive control circuit according to an embodiment of the present invention.

[0037] Figure 4 This is a flowchart illustrating a control method for a drive control circuit according to an embodiment of the present invention.

[0038] Among them: 10-power switch, 12-controller, 14-controllable resistor.

[0039] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0040] In the description of this invention, it should be noted that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "contact," and "communication" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] In industrial applications, power devices such as IGBTs or MOSFETs are typically used to form switching circuits to provide power to the circuitry. In conventional applications, the parameters of the circuits surrounding the switching circuit are fixed, and the conduction speed of the power devices is also fixed. Furthermore, the downstream circuitry is generally a capacitive load, meaning that the faster the voltage rises at power-on, the larger the starting current. This can generate a large inrush current at the moment the switching circuit turns on. While this may not cause immediate damage during a few startup cycles, prolonged exposure to high current surges can lead to irreversible damage to the controller.

[0043] To solve the above-mentioned technical problems, a first aspect of the present invention provides a drive control circuit, combined with... Figure 1 The topology diagram shows that the drive control circuit includes a power switch 10 and a controller 12 that controls its start-up or shutdown. The drive control circuit also includes:

[0044] A controllable resistor 14 is connected in series between the controller 12 and the gate of the power switch 10. The controllable resistor 14 is used to adjust the gate drive resistance of the power switch 10.

[0045] The current detection module is connected to the drain of the power switch 10 and is used to collect the starting current of the power switch 10.

[0046] The controller 12 is configured to adjust the resistance of the controllable resistor 14 according to the starting current so that the starting current is within a preset range.

[0047] In this embodiment, the controller 12 is preferably an MCU controller, the power switch 10 includes IGBT (insulated gate bipolar transistor), field effect transistor, etc., preferably an IGBT, and the controllable resistor 14 is preferably a digital potentiometer.

[0048] Specifically, the drive control circuit of this embodiment is further described using the preferred method described above: The MCU is the core of the circuit controller, responsible for functions such as IGBT drive signal transmission, digital potentiometer resistance adjustment, and monitoring of circuit startup current. The IGBT is the power switching device of the circuit, responsible for controlling the power supply to the load; its turn-on speed and turn-on current are controlled by the gate drive resistor. The digital potentiometer, with its resistor end connected in series between the MCU's PWM digital I / O terminal and the IGBT gate, provides an adjustable gate drive resistor for the IGBT; its resistance value is controlled by the MCU's communication commands. By connecting a current detection module to the drain of the power switch, the circuit startup current is monitored, and the information is fed back to the MCU. The MCU then changes the digital potentiometer resistance value to control the IGBT startup current and adjust the IGBT turn-on speed, thereby controlling the system startup current within a preset range and ensuring safe circuit startup.

[0049] A second aspect of the present invention provides a control method for a drive control circuit of the first aspect, wherein the drive control circuit is provided with a start-up current adaptive identification mode, combined with Figure 2 The flowchart illustrates the control method, which includes S1 to S4, wherein:

[0050] S1, in the start-up current adaptive identification mode, controls the power switch to start;

[0051] S2 monitors the starting current of the power switch;

[0052] S3, determine whether the starting current is within the preset range; if not, proceed to S4; if yes, proceed to S5.

[0053] S4 adjusts the resistance of the digital potentiometer to keep the starting current within a preset range;

[0054] S5: Save the current resistance value and exit the startup current adaptive identification mode.

[0055] In this embodiment, after the controller is powered on, it enters the adaptive startup current recognition mode. In this mode, the controller starts the PWM digital I / O port to output a high level to drive the IGBT to conduct. The current detection circuit samples the current at the moment the IGBT is turned on and judges the startup current during the sampling process to determine whether it is within the preset range. If the measured current is not within the preset range, it means that the startup current is either higher or lower than the circuit design range. At this time, the MCU adjusts the resistance value of the digital potentiometer according to the required current to select the appropriate startup current for the circuit to ensure safe circuit startup. The current resistance value of the digital potentiometer is stored for subsequent startup.

[0056] The drive control circuit of this embodiment can automatically adjust the conduction speed of the power devices in the switching circuit according to the state of the downstream power circuit, so as to achieve the effect of controlling the starting current of the circuit and making it more versatile.

[0057] Further, optionally, combined Figure 3 The flowchart shows that S4 includes S41 to S43, where:

[0058] S41 controls the power switch to turn off;

[0059] S42, when the starting current exceeds the upper limit of the preset range, increase the resistance of the digital potentiometer;

[0060] S43, when the starting current is less than the lower limit of the preset range, reduce the resistance of the digital potentiometer.

[0061] After the power switch is turned off, the resistance of the digital potentiometer is adjusted according to the current. When the starting current exceeds the upper limit of the preset range, the starting current is higher than the circuit design range, and it needs to be reduced. The PWM digital I / O output is low to turn off the IGBT, and the digital potentiometer resistance is increased (denoted by R++) to reduce the starting current. When the starting current is less than the lower limit of the preset range, the starting current is lower than the circuit design range, resulting in slow circuit startup, and it needs to be increased. The PWM digital I / O output is low to turn off the IGBT, and the digital potentiometer resistance is decreased (denoted by R--) to increase the starting current and improve the circuit startup speed.

[0062] Further, optionally, increasing or decreasing the resistance value of the digital potentiometer includes the following steps:

[0063] (1) Determine the adjustment value based on the difference between the starting current and the upper or lower limit value;

[0064] (2) Increase or decrease the resistance of the digital potentiometer according to the adjustment value.

[0065] Further optionally, determining the corresponding adjustment value based on the difference between the starting current and the upper or lower limit includes: dividing the difference into multiple intervals, each interval corresponding to an adjustment value; after calculating the difference, determining the interval of the difference, thereby determining the corresponding adjustment value.

[0066] Specifically, when the resistance of a digital potentiometer needs to be increased, the adjustment value is determined based on the difference between the starting current and the upper limit value, and the resistance of the digital potentiometer is increased accordingly. Conversely, when the resistance of a digital potentiometer needs to be decreased, the adjustment value is determined based on the difference between the starting current and the lower limit value, and the resistance of the digital potentiometer is decreased accordingly. Specifically, the larger the difference, the greater the corresponding resistance adjustment. Therefore, the difference can be divided into multiple intervals, each corresponding to an adjustment value. After calculating the difference, the interval of the difference is determined to identify the corresponding adjustment value. This adjustment value is then used to increase or decrease the resistance of the digital potentiometer. This allows for more precise adjustment of the digital potentiometer's resistance and reduces the number of adjustments required.

[0067] Further, optionally, after increasing or decreasing the resistance value of the digital potentiometer, the drive control method further includes:

[0068] The process then proceeds to the step of controlling the power switch to initiate the startup, until the startup current is determined to be within the preset range.

[0069] The MCU adjusts the resistance of the digital potentiometer according to the required current, and repeatedly starts and collects the starting current to finally select the appropriate starting current for the circuit to ensure safe circuit startup.

[0070] Further, optionally, combined Figure 4 The flowchart illustrates that before the power switch is started in step S1, the drive control method further includes S0:

[0071] S0 adjusts the resistance of the digital potentiometer to the preset resistance value.

[0072] The following is combined Figure 4 The driving control method of this embodiment will be further explained.

[0073] The MCU writes the initial resistance value R to the digital potentiometer via SPI (Serial Peripheral Interface) communication and starts the PWM digital I / O to drive the IGBT to conduct. The current detection circuit samples the current when the IGBT is turned on and compares the measured current I during the sampling process with Imin and Imax stored in the MCU.

[0074] When Imin ≤ I ≤ Imax, it means that the IGBT conduction current meets the reasonable range preset by the MCU. At this time, the current digital potentiometer resistance value R is saved. 当前 This is for subsequent normal startup and to end this current adaptive mode operation;

[0075] When the current I > Imax, the startup current exceeds the circuit design range, requiring a reduction in startup current. The PWM digital I / O outputs a low level to turn off the IGBT, and the digital potentiometer resistance (denoted by R++) is increased to reduce the startup current. The PWM digital I / O then restarts, driving the IGBT to conduct again and entering the next current detection cycle.

[0076] When the current I < Imin, the starting current is lower than the circuit design range, resulting in slow circuit startup, necessitating an increase in the starting current. The PWM digital I / O outputs a low level to turn off the IGBT, and the digital potentiometer resistance (represented by R--) is reduced to increase the starting current and thus improve the circuit startup speed. The PWM digital I / O then restarts to turn the IGBT on and enters the next current sensing cycle.

[0077] A third aspect of the present invention provides a non-transitory computer-readable storage medium having program instructions stored thereon, wherein when the program instructions are executed by one or more processors, the one or more processors are used to implement the method of any one of the second aspects.

[0078] The fourth aspect of the present invention provides a switching circuit that employs the drive control circuit of the first aspect, or the control method of any one of the second aspects, or has a non-transitory computer-readable storage medium of the third aspect.

[0079] This invention provides a method for automatically adjusting the conduction speed of power devices in a switching circuit based on the state of the downstream power circuit, thereby controlling the circuit startup current. By adding a digital potentiometer to the gate of the power device and adjusting its resistance, the conduction rate of the power device can be adjusted. Real-time monitoring of each startup current signal and changing the resistance of the digital potentiometer via an MCU further regulates the conduction speed of the power device, thereby controlling the system startup current and ensuring safe circuit startup.

[0080] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0081] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A drive control circuit, the drive control circuit comprising a power switch and a controller for controlling its start-up or shutdown, characterized in that, The source of the power switch is used to connect to a capacitive load, the drive control circuit has a startup current adaptive identification mode, and the drive control circuit further includes: A controllable resistor is connected in series between the controller and the gate of the power switch, and the controllable resistor is used to adjust the gate drive resistance of the power switch; A current detection module is connected to the drain of the power switch and is used to collect the starting current of the power switch. The controller is connected to both the controllable resistor and the current detection module. In the start-up current adaptive identification mode, the controller is configured as follows: a) Control the power switch to start; b) Monitor the startup current of the power switch; c) Determine whether the starting current is within the preset range; d) If not, control the power switch to turn off, adjust the resistance of the controllable resistor according to the starting current, and then proceed to step a) until it is determined that the starting current is within the preset range; e) Save the current resistance value of the controllable resistor and exit the start-up current adaptive identification mode. The current resistance value is used for subsequent startup.

2. The drive control circuit according to claim 1, characterized in that, The controllable resistor is a digital potentiometer.

3. A control method for a drive control circuit as described in claim 1 or 2, characterized in that, The drive control circuit is equipped with a start-up current adaptive identification mode, and the control method is applied to the start-up current adaptive identification mode. The method includes: Control the power switch to start; Monitor the startup current of the power switch; Determine whether the starting current is within a preset range; If not, the power switch is turned off, the resistance of the controllable resistor is adjusted, and the process returns to the step of controlling the power switch to start, until the starting current is within the preset range. Save the current resistance value of the controllable resistor and exit the start-up current adaptive identification mode. The current resistance value is used for subsequent startup.

4. The control method according to claim 3, characterized in that, Adjusting the resistance value of the controllable resistor includes: When the starting current is greater than the upper limit of the preset range, the resistance value of the controllable resistor is increased; When the starting current is less than the lower limit of the preset range, the resistance value of the controllable resistor is reduced.

5. The control method according to claim 4, characterized in that, Increasing or decreasing the resistance value of the controllable resistor includes: The corresponding adjustment value is determined based on the difference between the starting current and the upper limit value or the lower limit value; The resistance value of the controllable resistor is increased or decreased according to the corresponding adjustment value.

6. The control method according to claim 5, characterized in that, The step of determining the corresponding adjustment value based on the difference between the starting current and the upper limit or the lower limit includes: dividing the difference into multiple intervals, each interval corresponding to an adjustment value; after calculating the difference, determining the interval of the difference, thereby determining the corresponding adjustment value.

7. The control method according to claim 3, characterized in that, Before controlling the power switch to start, the control method further includes: Adjust the resistance value of the controllable resistor to the preset resistance value.

8. A non-transitory computer-readable storage medium having stored program instructions thereon, which, when executed by one or more processors, are configured to implement the control method according to any one of claims 3-7.

9. A switching circuit, characterized in that, It employs the drive control circuit as described in claim 1 or 2, or the control method as described in any one of claims 3-7, or has a non-transitory computer-readable storage medium as described in claim 8.

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