A circuit and discharge method of a DC-DC power supply maintenance module

Abstract

The present application relates to a circuit and discharge method of a DC-DC power supply maintenance module, wherein the circuit includes a controller, a drive circuit, a charging circuit, an energy storage capacitor, a discharge circuit, and a DC-DC power supply, wherein the discharge circuit includes a discharge inductor and a discharge switch tube; the controller is connected to the discharge switch tube through the drive circuit, one end of the energy storage capacitor is connected to the positive terminal of the charging circuit and the discharge switch tube respectively, the positive terminal of the charging circuit is connected to one end of the discharge inductor through the discharge switch tube, the other end of the discharge inductor is connected to the positive electrode of the DC-DC power supply, and the negative electrode of the DC-DC power supply and the other end of the energy storage capacitor are both connected to the negative terminal of the charging circuit. The present application solves the problem that when the existing DC-DC power supply maintenance module is working, the voltage difference between the energy storage capacitor in the maintenance module and the DC-DC power converter is large, resulting in a very large impact current generated at the moment of discharging the energy storage capacitor, which is easy to damage the switch tube in the maintenance module.

Description

Background Art

[0002] As DC-DC power converters are used in more and more applications, higher requirements are placed on their performance. The power maintenance module circuit at the front end of the DC-DC power converter can use the energy storage capacitor to provide energy to the DC-DC power converter after the input power is off, so that the DC-DC power converter can work for a short period of time. As the power of the DC-DC power converter is getting larger and larger, in order to store more energy, the voltage of the energy storage capacitor in the maintenance module for power-off maintenance of the DC-DC power converter is getting higher and higher. Therefore, when the maintenance module is working, the voltage difference between the energy storage capacitor in the maintenance module and the DC-DC power converter is large, resulting in a very large impact current generated by the instantaneous discharge of the energy storage capacitor, which is easy to damage the switch tube in the maintenance module. Summary of the invention

[0003] In order to overcome the problem that when the existing DC-DC power supply maintenance module is working, the voltage difference between the energy storage capacitor in the maintenance module and the DC-DC power converter is large, resulting in a very large impact current generated at the moment of discharging the energy storage capacitor, which is easy to damage the switch tube in the maintenance module, the present application provides a circuit and discharge method of a DC-DC power supply maintenance module.

[0004] In the first aspect, in order to solve the above technical problems, the present application provides a circuit of a DC-DC power supply maintenance module, including a controller, a drive circuit, a charging circuit, an energy storage capacitor, a discharge circuit, and a DC-DC power supply, wherein the discharge circuit includes a discharge inductor and a discharge switch tube;

[0005] The controller is connected to the discharge switch tube through the driving circuit, one end of the energy storage capacitor is connected to the positive terminal of the charging circuit and the discharge switch tube respectively, the positive terminal of the charging circuit is connected to one end of the discharge inductor through the discharge switch tube, the other end of the discharge inductor is connected to the positive electrode of the DC-DC power supply, and the negative electrode of the DC-DC power supply and the other end of the energy storage capacitor are both connected to the negative terminal of the charging circuit; when the discharge circuit is working, the discharge inductor makes the impact current generated by the energy storage capacitor at the moment of discharge less than or equal to the current threshold of the discharge switch tube.

[0006] Furthermore, the discharge circuit also includes a freewheeling diode and an input capacitor;

[0007] The input capacitor is connected in parallel with the DC-DC power supply; the reverse end of the freewheeling diode is connected between the discharge switch tube and the discharge inductor, and the forward end of the freewheeling diode is connected to the negative terminal of the charging circuit.

[0008] Furthermore, a first diode is connected between the discharge inductor and the DC-DC power supply.

[0009] Furthermore, the charging circuit includes a charging power supply, a first freewheeling switch tube, a charging inductor and a second diode;

[0010] The positive electrode of the charging power supply is connected to one end of the charging inductor through the first freewheeling switch tube, the other end of the charging inductor is connected to one end of the energy storage capacitor, the reverse end of the second diode is connected between the first freewheeling switch tube and the charging inductor, and the forward end of the second diode, the other end of the energy storage capacitor, the forward end of the freewheeling diode and the negative electrode of the DC-DC power supply are all connected to the negative electrode of the charging power supply.

[0011] Furthermore, the charging inductor is connected to the negative electrode of the charging power source through the second freewheeling switch tube.

[0012] Furthermore, a third diode is connected between the other end of the charging inductor and one end of the energy storage capacitor.

[0013] In a second aspect, the present application further provides a discharge method for a DC-DC power supply maintenance module, which is applied to a circuit of a DC-DC power supply maintenance module, and the method includes:

[0014] When the discharge circuit is working, the discharge inductor in the discharge circuit is used to limit the impact current generated by the energy storage capacitor at the moment of discharge to a value less than or equal to the current threshold of the discharge switch tube in the discharge circuit, so that the discharge switch tube can work safely;

[0015] Obtaining a comparison of the voltages of the energy storage capacitor and the input capacitor in the discharge circuit;

[0016] Based on the voltage comparison, the discharge switch tube is used to control the discharge circuit to discharge.

[0017] The beneficial effects of the present application are: by setting a discharge inductor and a discharge switch tube between the charging circuit and the DC-DC power supply, the circuit of the present application can limit the impact current generated by the energy storage capacitor to less than or equal to the current threshold of the discharge switch tube by the discharge inductor when the discharge circuit is working, ensuring that the discharge switch tube can always be in a safe working state, and avoiding damage to the discharge switch tube due to excessive instantaneous impact current. At the same time, by comparing the voltage magnitudes of the energy storage capacitor and the input capacitor in the discharge circuit, and based on the voltage magnitude comparison, the discharge circuit is controlled by the discharge switch tube to discharge, so that the current in the discharge circuit during the discharge of the energy storage capacitor is always less than or equal to the current threshold of the discharge switch tube under the limitation of the discharge inductor, which can not only protect the safe operation of the discharge switch tube, but also reduce the probability of damage to the DC-DC power supply connected to the discharge circuit due to excessive instantaneous impact current, thereby improving the discharge safety of the circuit of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A schematic diagram of the structure of a circuit of a DC-DC power supply maintenance module shown in an exemplary embodiment of the present application;

[0019] Figure 2 A schematic diagram of the structure of a circuit of a DC-DC power supply maintenance module shown in an exemplary embodiment of the present application;

[0020] Figure 3 A schematic flow chart of a discharge method for a DC-DC power supply maintenance module shown in an exemplary embodiment of the present application;

[0021] Figure 4 A schematic diagram showing a duty cycle change of a duty cycle situation in an exemplary embodiment of the present application;

[0022] Figure 5 This is a schematic diagram of the working state of the discharge circuit when the discharge switch tube is in the on state in an exemplary embodiment of the present application;

[0023] Figure 6 This is a schematic diagram of the working state of the discharge circuit when the discharge switch tube is in the off state in an exemplary embodiment of the present application;

[0024] Figure 7 The present invention is a flowchart of a discharge system for a DC-DC power supply maintenance module according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following examples are provided to further explain and supplement the present application and do not constitute any limitation to the present application.

[0026] The following describes a circuit and a discharge method of a DC-DC power supply maintenance module according to an embodiment of the present application in conjunction with the accompanying drawings.

[0027] See also Figure 1 , Figure 1 This application provides a circuit of a DC-DC power supply maintenance module, such as Figure 1 As shown, the present application provides a circuit of a DC-DC power supply maintenance module, including a controller, a drive circuit, a charging circuit, an energy storage capacitor, a discharge circuit, and a DC-DC power supply, wherein the discharge circuit includes a discharge inductor and a discharge switch tube;

[0028] The controller is connected to the discharge switch tube through the driving circuit, one end of the energy storage capacitor is connected to the positive terminal of the charging circuit and the discharge switch tube respectively, the positive terminal of the charging circuit is connected to one end of the discharge inductor through the discharge switch tube, the other end of the discharge inductor is connected to the positive electrode of the DC-DC power supply, and the negative electrode of the DC-DC power supply and the other end of the energy storage capacitor are both connected to the negative terminal of the charging circuit; when the discharge circuit is working, the discharge inductor makes the impact current generated by the energy storage capacitor at the moment of discharge less than or equal to the current threshold of the discharge switch tube.

[0029] A circuit of a DC-DC power supply maintenance module of the present embodiment arranges a discharge inductor and a discharge switch tube between a charging circuit and a DC-DC power supply, so that when the discharge circuit of the present application is working, the impact current generated by the energy storage capacitor at the moment of discharge can be limited by the discharge inductor to a current threshold value less than or equal to the discharge switch tube, thereby ensuring that the discharge switch tube can always be in a safe working state and avoiding damage to the discharge switch tube due to excessive instantaneous impact current.

[0030] Optionally, the discharge circuit further includes a freewheeling diode and an input capacitor;

[0031] The input capacitor is connected in parallel with the DC-DC power supply; the reverse end of the freewheeling diode is connected between the discharge switch tube and the discharge inductor, and the forward end of the freewheeling diode is connected to the negative terminal of the charging circuit.

[0032] In this embodiment, the energy storage capacitor is connected in parallel with the charging circuit, so that the charging circuit charges the energy storage capacitor, and after the energy storage capacitor is fully charged, when the discharge circuit is working, the electric energy in the energy storage capacitor slowly charges the DC-DC power supply through the discharge switch tube and the discharge inductor, so as to improve the charging safety of the energy storage capacitor.

[0033] The reverse end of the freewheeling diode is connected between the discharge switch tube and the discharge inductor, and the forward end is connected to the negative terminal of the charging circuit. When the discharge switch tube is in the off state, the discharge inductor can still form a loop with the DC-DC power supply through the freewheeling diode, so that the electric energy stored in the discharge inductor can continue to charge the DC-DC power supply, thereby further slowing down the discharge speed of the discharge circuit to reduce the discharge pressure of the discharge circuit, so that the electric energy generated by the charging circuit at the moment of power failure can be slowly charged to the DC-DC power supply, which can not only save the electric energy loss at the moment of power failure, but also improve the discharge safety of the discharge circuit.

[0034] Directly connecting an input capacitor in parallel at both ends of a DC-DC power supply can act as a filter. Since the capacitor has a charging and discharging function, when the voltage of the DC-DC power supply fluctuates, the charging and discharging function of the input capacitor can reduce the voltage fluctuation of the DC-DC power supply, thereby improving the discharge stability of the DC-DC power supply maintenance module.

[0035] Optionally, a first diode is connected between the discharge inductor and the DC-DC power supply.

[0036] In this embodiment, a first diode is connected between the discharge inductor and the DC-DC power supply to prevent the electric energy of the input capacitor during discharge and the electric energy of the DC-DC power supply from flowing back to the charging circuit, causing energy loss.

[0037] Optionally, the charging circuit includes a charging power supply, a first freewheeling switch tube, a charging inductor and a second diode;

[0038] The positive electrode of the charging power supply is connected to one end of the charging inductor through the first freewheeling switch tube, the other end of the charging inductor is connected to one end of the energy storage capacitor, the reverse end of the second diode is connected between the first freewheeling switch tube and the charging inductor, and the forward end of the second diode, the other end of the energy storage capacitor, the forward end of the freewheeling diode and the negative electrode of the DC-DC power supply are all connected to the negative electrode of the charging power supply.

[0039] In this embodiment, the positive electrode of the charging power supply is connected to one end of the charging inductor through the first freewheeling switch tube, the other end of the charging inductor is connected to one end of the energy storage capacitor, and the other end of the energy storage capacitor is connected to the negative electrode of the charging power supply, so that the first freewheeling switch tube can control whether the charging power supply charges the energy storage capacitor by controlling itself to be in an on state or an off state. That is, when the first freewheeling switch tube is in the on state, the charging power supply charges the energy storage capacitor, and when the first freewheeling switch tube is in the off state, the charging power supply stops charging the energy storage capacitor. At the same time, the charging inductor can limit the current in the charging circuit during the charging process to be less than or equal to the current threshold of the first freewheeling switch tube, thereby improving the charging safety of the charging circuit.

[0040] The reverse end of the second diode is connected between the first freewheeling switch tube and the charging inductor, and the forward end of the second diode is connected to the negative electrode of the charging power supply. In this way, when the first freewheeling switch tube is in the off state, the charging inductor and the energy storage capacitor cannot form a loop through the second diode, thereby avoiding the backflow of electric energy in the energy storage capacitor and reducing the loss of electric energy.

[0041] Optionally, the charging inductor is connected to the negative electrode of the charging power source through a second freewheeling switch tube.

[0042] In this embodiment, the charging inductor is connected to the negative electrode of the charging power supply through the second freewheeling switch tube, and when the first freewheeling switch tube is in the off state, the second freewheeling switch tube is in the on state, and when the first freewheeling switch tube is in the on state, the second freewheeling switch tube is in the off state. In this way, the electric energy emitted by the charging circuit when charging the energy storage capacitor will not be divided by the second freewheeling switch tube and the second diode, thereby improving the charging efficiency of the energy storage capacitor. When the charging circuit does not charge the energy storage capacitor, the second freewheeling switch tube is in the on state, the discharge circuit is short-circuited, and the electric energy in the charging inductor is only transmitted to the second freewheeling switch tube and the second diode through the circuit loop formed by the charging inductor, the second freewheeling switch tube and the second diode, which can directly consume the electric energy in the charging inductor in the charging circuit, thereby further improving the safety of the charging circuit. Among them, the first freewheeling switch tube and the second freewheeling switch tube are Buck-Boost (polarity reversal buck-boost type) switch tubes.

[0043] Optionally, a third diode is connected between the other end of the charging inductor and one end of the energy storage capacitor.

[0044] In this embodiment, a third diode is connected between the charging inductor and the energy storage capacitor, so that when the first freewheeling switch tube is in the off state, the electric energy stored in the energy storage capacitor in the discharge circuit will not flow back to the charging circuit, thereby avoiding the influence of the electric energy in the energy storage capacitor on the charging circuit, thereby further improving the safety of the charging circuit.

[0045] In some embodiments, the discharge switch tube, the first freewheeling switch tube and the second freewheeling switch tube of the present application may be triodes or MOS tubes. The components in the charging circuit of the present application form a Buck-Boost topology structure.

[0046] See also Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a circuit structure of a DC-DC power supply maintenance module according to an exemplary embodiment of the present application. Figure 2 As shown, the circuit of the DC-DC power supply maintenance module includes a charging circuit, an energy storage capacitor C charge , discharge circuit, DC-DC power supply, drive circuit and DSP controller, the circuit also includes and fourth diode. The charging circuit includes a charging power supply, a first freewheeling switch tube S2, a charging inductor L1, a second diode D2, a third diode D3, and a second freewheeling switch tube S3, and the discharge circuit includes a discharge switch tube S1, a freewheeling diode D1, a discharge inductor L2, a first diode D4, and an input capacitor C0.

[0047] The positive electrode Vin of the charging power supply is connected to the input end of the first freewheeling switch tube S2, the output end of the first freewheeling switch tube S2 is respectively connected to one end of the charging inductor L1 and the reverse end of the second diode D2, and the other end of the charging inductor L1 is respectively connected to the forward end of the third diode D3 and the input end of the second freewheeling switch tube S3;

[0048] The reverse end of the third diode D3 is connected to the energy storage capacitor C charge One end of the discharge switch tube S1 is connected to the input end of the discharge switch tube S1, the signal control end of the discharge switch tube S1 is connected to the controller through the drive circuit, the output end of the discharge switch tube S1 is respectively connected to the reverse end of the freewheeling diode D1 and one end of the discharge inductor L2, the other end of the discharge inductor L2 is connected to the forward end of the first diode D4, and the reverse end of the first diode D4 is respectively connected to one end of the input capacitor C0 and the positive electrode of the DC-DC power supply;

[0049] The negative electrode of the DC-DC power supply, the other end of the input capacitor C0, the positive end of the freewheeling diode D1, and the energy storage capacitor C chargeThe other end of the energy storage capacitor C charge The voltage across the two ends is V charge , the voltage across the input capacitor C0 is Vo;

[0050] The positive electrode Vin of the charging power supply is connected to the positive electrode of the DC-DC power supply through the fourth diode, so that the charging power supply charges the DC-DC power supply through the fourth diode. When the charging power supply stops charging the DC-DC power supply, the energy storage capacitor starts to discharge, and the discharge circuit starts to work at this time. The discharge inductor in the discharge circuit limits the impact current generated by the energy storage capacitor to less than or equal to the current threshold of the discharge switch tube, ensuring that the discharge switch tube can always be in a safe working state and avoiding damage to the discharge switch tube due to excessive instantaneous impact current.

[0051] A discharge method for a DC-DC power supply maintenance module in an embodiment of the present application is applied to a terminal device. In the present application scheme, the terminal device is used as the execution subject to illustrate the present application scheme. The terminal device is used to execute the steps of a discharge method for a DC-DC power supply maintenance module.

[0052] See also Figure 3 , Figure 3 This application discloses a discharge method for a DC-DC power supply maintenance module, such as Figure 3 As shown, the present application provides a discharge method for a DC-DC power supply maintenance module, which is applied to a circuit of the above-mentioned DC-DC power supply maintenance module, and the method includes:

[0053] Step S31, when the discharge circuit is working, the discharge inductor in the discharge circuit is used to limit the impact current generated by the energy storage capacitor at the moment of discharge to a current threshold value less than or equal to the discharge switch tube in the discharge circuit, so that the discharge switch tube can work safely;

[0054] Step S32, obtaining a comparison of the voltages of the energy storage capacitor and the input capacitor in the discharge circuit;

[0055] Step S33, based on the voltage comparison, using the discharge switch tube to control the discharge circuit to discharge.

[0056] A discharge method for a DC-DC power supply maintenance module of the present embodiment compares the voltages of an energy storage capacitor and an input capacitor in a discharge circuit, and controls the discharge circuit to discharge using a discharge switch tube based on the voltage comparison, so that the current in the discharge circuit during the discharge of the energy storage capacitor is always less than or equal to the current threshold of the discharge switch tube under the limitation of the discharge inductance, which can not only protect the safe operation of the discharge switch tube, but also reduce the probability of damage to the DC-DC power supply connected to the discharge circuit due to excessive instantaneous impact current, thereby improving the discharge safety of the circuit of the present application.

[0057] Optionally, the voltage comparison condition includes that the voltage across the energy storage capacitor is greater than the voltage across the input capacitor; based on the voltage comparison condition, using a discharge switch tube to control the discharge circuit to discharge, including:

[0058] When the voltage across the energy storage capacitor is greater than the voltage across the input capacitor, the discharge switch tube is controlled to receive the PWM wave sent by the controller;

[0059] Determine the duty cycle of the discharge switch tube based on the PWM wave;

[0060] Based on the discharge switch tube and the duty cycle, the energy storage capacitor or the discharge inductor is controlled to charge the input capacitor and the DC-DC power supply so that the discharge circuit can discharge.

[0061] In this embodiment, when the discharge circuit is working, the input voltage is detected, and when the input voltage is less than the threshold voltage, the voltage comparison between the energy storage capacitor and the input capacitor is detected. When the voltage comparison is that the voltage across the energy storage capacitor is greater than the voltage across the input capacitor, the discharge switch tube is controlled by the PWM wave emitted by the controller to obtain the duty cycle of the discharge switch tube, and based on the discharge switch tube and the duty cycle, the energy storage capacitor or the discharge inductor is controlled to charge the input capacitor and the DC-DC power supply to slowly consume the electric energy stored in the energy storage capacitor and the discharge inductor, so as to achieve the discharge effect of the discharge circuit, avoid the instantaneous current generated by the sudden disconnection of the charging circuit causing damage to the DC-DC power supply, thereby improving the discharge safety of the discharge circuit. Among them, the duty cycle represents the proportion of the conduction time relative to the total time, and the PWM wave emitted by the controller can control the discharge switch tube to be turned on or off.

[0062] See also Figure 4 , Figure 4 The duty cycle variation diagram showing the duty cycle situation in this application is shown in FIG. Figure 4 As shown, the duty cycle of the discharge switch tube corresponding to the first wave of the PWM wave is D=V0 / V charge , duty cycle per interval T sIncreasing by ΔD, the duty cycle of the discharge switch tube corresponding to the second wave is (D+ΔD), and the duty cycle of the discharge switch tube corresponding to the Nth wave is (D+NΔD), until the duty cycle is 100%, at which time the discharge switch tube is in a normally on state, then V charge Equal to V0. Where V0 represents the voltage across the input capacitor, V charge represents the voltage across the energy storage capacitor, D represents the duty cycle, ΔD represents the duty cycle increment, T s Indicates the period of the PWM wave.

[0063] Optionally, based on the discharge switch tube and the duty cycle, controlling the energy storage capacitor or the discharge inductor to charge the input capacitor and the DC-DC power supply includes:

[0064] Based on the duty cycle, the energy storage capacitor and the input capacitor, the current change of the discharge current flowing through the discharge inductor is obtained;

[0065] The discharge current is calculated as follows:

[0066] Ipk=(V charge -V0)DT s / L;

[0067] Where, Ipk represents the discharge current flowing through the discharge inductor, V charge represents the voltage across the energy storage capacitor, V0 represents the voltage across the input capacitor, D represents the duty cycle, T s represents the period of PWM wave, L represents the inductance of discharge inductor;

[0068] When the discharge switch tube is in the on state, the energy storage capacitor is controlled to charge the input capacitor and the DC-DC power supply based on the current change;

[0069] When the discharge switch tube is in the off state, the discharge inductor is controlled based on the current change to charge the input capacitor and the DC-DC power supply.

[0070] In this embodiment, the current change of the discharge current flowing through the discharge inductor is obtained based on the duty cycle, the energy storage capacitor and the input capacitor, and when the discharge switch tube is in the on state, the energy storage capacitor is controlled to charge the input capacitor and the DC-DC power supply based on the current change; when the discharge switch tube is in the off state, the discharge inductor is controlled to charge the input capacitor and the DC-DC power supply based on the current change. In this way, the PWM wave emitted by the controller causes the energy storage capacitor and the discharge inductor to cross-charge the input capacitor and the DC-DC power supply slowly, so as to slow down the discharge speed of the discharge circuit, thereby improving the safety of the discharge circuit.

[0071] In this embodiment, the discharge current flowing through the discharge inductor is (Vcharge -V0) / L increases with the change of PWM wave until the duty cycle of the discharge switch tube corresponding to the PWM wave is 100% and the discharge current reaches a peak value, that is, the discharge current reaches the current threshold of the discharge switch tube. The inductance of the discharge inductor in this embodiment is determined by the energy storage capacitor, the input capacitor and the DC-DC power supply, and the calculation formula of the inductance of the discharge inductor is: L=ΔVTm / Iin, where L represents the inductance of the discharge inductor, Tm represents the time when the electric energy exists in the input capacitor, ΔV represents the voltage difference between the energy storage capacitor and the input capacitor, and Iin represents the input current of the DC-DC power supply.

[0072] See also Figure 5 , Figure 5 In this application, the working state diagram of the discharge circuit when the discharge switch tube is in the on state is as follows: Figure 5 As shown, the voltage V across the energy storage capacitor charge When the discharge switch tube S1 is in the on state, the freewheeling diode is cut off, and the energy storage capacitor C charge The outflowing current flows through the discharge switch tube S1, the discharge inductor L2 and the first diode D4 in sequence, and finally flows into the DC-DC power supply and the input capacitor C0 and then returns to the energy storage capacitor to power the DC-DC power supply and charge the input capacitor C0.

[0073] See also Figure 6 , Figure 6 Schematic diagram of the working state of the discharge circuit when the discharge switch tube is in the off state in this application, such as Figure 6 As shown, the voltage V across the energy storage capacitor charge When the voltage across the input capacitor V0 is greater than the voltage across the input capacitor, and the discharge switch tube S1 is in the off state, the discharge inductor L2, the flyback diode D1, the input capacitor C0, and the DC-DC power supply form a circuit loop, and current flows out of the discharge inductor L2, flows into the input capacitor C0 and the DC-DC power supply through the flyback diode D1, and then flows back to the discharge inductor L2 through the flyback diode D1. At this time, the discharge inductor L2 not only supplies power to the DC-DC power supply, but also charges the input capacitor C0.

[0074] Optionally, the voltage comparison condition includes that the voltage across the energy storage capacitor is equal to the voltage across the input capacitor; based on the voltage comparison condition, using a discharge switch tube to control the discharge circuit to discharge, including:

[0075] When the voltage comparison shows that the voltage across the energy storage capacitor is equal to the voltage across the input capacitor, the discharge switch tube is controlled to remain in the on state, and the energy storage capacitor is controlled to charge the DC-DC power supply so that the discharge circuit discharges.

[0076] In this embodiment, when the voltage across the energy storage capacitor is equal to the voltage across the input capacitor, the controller continuously outputs a high level, so that the duty cycle of the discharge switch tube is equal to 100%, that is, the discharge switch tube is continuously in the on state. At this time, the discharge switch tube remains in the on state, and the energy storage capacitor and the input capacitor charge the DC-DC power supply at the same time, so as to release the residual electric energy of the energy storage capacitor in the discharge circuit while also releasing the electric energy in the input capacitor; when the voltage across the energy storage capacitor is less than the undervoltage threshold of the DC-DC power supply, the switch tube S1 is turned off, the discharge ends, and the discharge process of the discharge circuit is safely ended, so that the discharge safety of the discharge circuit can be ensured.

[0077] The present application discloses a circuit and a discharge method of a DC-DC power supply maintenance module. A discharge circuit is connected between a charging circuit and a DC-DC power supply, and a discharge inductor is provided in the discharge circuit to limit the peak value of the impact current generated at the moment of discharge of the energy storage capacitor, so that the peak value of the discharge current flowing through the discharge switch tube in the discharge circuit is less than or equal to the current threshold of the discharge switch tube, thereby protecting the discharge switch tube, and using the discharge switch tube to cross-use the energy storage capacitor and the discharge inductor in the discharge circuit to charge the DC-DC power supply under the control of a PWM wave, so that when the discharge circuit is working, the impact current generated at the moment of discharge of the energy storage capacitor is slowly released in the discharge circuit, thereby improving the discharge safety of the circuit of the present application.

[0078] See also Figure 7 , Figure 7 This application discloses a discharge system for a DC-DC power supply maintenance module, such as Figure 7 As shown, the present application provides a discharge system for a DC-DC power supply maintenance module, comprising:

[0079] The limiting module is used to limit the impact current generated by the energy storage capacitor discharging instantaneously to a value less than or equal to the current threshold of the discharge switch tube in the discharge circuit by using the discharge inductance in the discharge circuit when the discharge circuit is working, so as to make the discharge switch tube work safely;

[0080] An acquisition module is used to obtain a voltage comparison between the energy storage capacitor and the input capacitor in the discharge circuit;

[0081] The control module is used to control the discharge circuit to discharge by using the discharge switch tube based on the voltage comparison.

[0082] A discharge system for a DC-DC power supply maintenance module of the present embodiment uses a limiting module to limit the impact current to be less than or equal to the current threshold of a discharge switch tube in the discharge circuit when the charging circuit is powered off, and an acquisition module obtains the voltage comparison between the energy storage capacitor and the input capacitor in the discharge circuit, and a control module uses the discharge switch tube to control the discharge circuit to discharge based on the voltage comparison, so that the current in the discharge circuit is always less than or equal to the current threshold of the discharge switch tube under the limitation of the discharge inductance during the discharge of the energy storage capacitor, which can not only protect the safe operation of the discharge switch tube, but also reduce the probability of damage to the DC-DC power supply connected to the discharge circuit due to excessive instantaneous impact current, thereby improving the discharge safety of the circuit of the present application.

[0083] Optionally, the voltage comparison condition includes that the voltage across the energy storage capacitor is greater than the voltage across the input capacitor; the control module is specifically used to:

[0084] When the voltage across the energy storage capacitor is greater than the voltage across the input capacitor, the discharge switch tube is controlled to receive the PWM wave sent by the controller;

[0085] Determine the duty cycle of the discharge switch tube based on the PWM wave;

[0086] Based on the discharge switch tube and the duty cycle, the energy storage capacitor or the discharge inductor is controlled to charge the input capacitor and the DC-DC power supply so that the discharge circuit can discharge.

[0087] Optionally, the control module is specifically configured to:

[0088] Based on the duty cycle, the energy storage capacitor and the input capacitor, the current change of the discharge current flowing through the discharge inductor is obtained;

[0089] When the discharge switch tube is in the on state, the energy storage capacitor is controlled to charge the input capacitor and the DC-DC power supply based on the current change;

[0090] When the discharge switch tube is in the off state, the discharge inductor is controlled based on the current change to charge the input capacitor and the DC-DC power supply.

[0091] Optionally, the voltage comparison condition includes that the voltage across the energy storage capacitor is equal to the voltage across the input capacitor; and the control module is specifically used to:

[0092] When the voltage comparison shows that the voltage across the energy storage capacitor is equal to the voltage across the input capacitor, the discharge switch tube is controlled to remain in the on state, and the energy storage capacitor is controlled to charge the DC-DC power supply so that the discharge circuit discharges.

[0093] A computing device according to an embodiment of the present application includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, some or all steps of the above-mentioned discharge method for a DC-DC power supply maintenance module are implemented.

[0094] Among them, the computing device can be a computer, and correspondingly, its program is computer software. The above-mentioned parameters and steps in a computing device of the present application can refer to the parameters and steps in an embodiment of a discharge method for a DC-DC power supply maintenance module mentioned above, and will not be repeated here.

[0095] In an embodiment of the present application, a computer-readable storage medium is provided, in which instructions are stored. When the instructions are executed, the steps of the above-mentioned discharge method for a DC-DC power supply maintenance module are executed.

[0096] The computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0097] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method of the embodiment of the present disclosure. The aforementioned computer-readable storage medium may be a non-transitory computer-readable storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other media that can store program codes, or a transient computer-readable storage medium.

[0098] The flowchart and block diagram in the accompanying drawings illustrate the possible architecture, functions and operations of the system, method and computer program product according to various embodiments of the present application. Wherein, each box in the flowchart or block diagram can represent a module, a program segment, or a part of the code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0099] Those skilled in the art know that the present application can be implemented as a system, method or computer program product. Therefore, the present disclosure can be specifically implemented in the following forms, namely: it can be complete hardware, it can be complete software (including firmware, resident software, microcode, etc.), or it can be a combination of hardware and software, generally referred to as "circuit", "module" or "system" herein. In addition, in some embodiments, the present application can also be implemented in the form of a computer program product in one or more computer-readable media, and the computer-readable medium contains computer-readable program code. Computer-readable storage media can be, for example, but not limited to - electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or devices, or any combination of the above.

[0100] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0101] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A circuit of a DC-DC power supply maintenance module, characterized in that: It includes a controller, a driving circuit, a charging circuit, an energy storage capacitor, a discharge circuit, and a DC-DC power supply, wherein the discharge circuit includes a discharge inductor and a discharge switch tube; The controller is connected to the discharge switch tube through the drive circuit, one end of the energy storage capacitor is connected to the positive terminal of the charging circuit and the discharge switch tube respectively, the positive terminal of the charging circuit is connected to one end of the discharge inductor through the discharge switch tube, the other end of the discharge inductor is connected to the positive electrode of the DC-DC power supply, and the negative electrode of the DC-DC power supply and the other end of the energy storage capacitor are both connected to the negative terminal of the charging circuit; when the discharge circuit is working, the discharge inductor makes the impact current generated by the energy storage capacitor at the moment of discharge less than or equal to the current threshold of the discharge switch tube; The discharge circuit also includes a freewheeling diode and an input capacitor; the input capacitor is connected in parallel with the DC-DC power supply; the reverse end of the freewheeling diode is connected between the discharge switch tube and the discharge inductor, and the forward end of the freewheeling diode is connected to the negative end of the charging circuit.

2. The circuit according to claim 1, characterized in that A first diode is connected between the discharge inductor and the DC-DC power supply.

3. The circuit according to claim 1 or 2, characterized in that: The charging circuit includes a charging power supply, a first freewheeling switch tube, a charging inductor and a second diode; The positive electrode of the charging power supply is connected to one end of the charging inductor through the first freewheeling switch tube, the other end of the charging inductor is connected to one end of the energy storage capacitor, the reverse end of the second diode is connected between the first freewheeling switch tube and the charging inductor, and the forward end of the second diode, the other end of the energy storage capacitor, the forward end of the freewheeling diode and the negative electrode of the DC-DC power supply are all connected to the negative electrode of the charging power supply.

4. The circuit according to claim 3, characterized in that The charging inductor is connected to the negative electrode of the charging power source through a second freewheeling switch tube.

5. The circuit according to claim 3, characterized in that A third diode is connected between the other end of the charging inductor and one end of the energy storage capacitor.

6. A discharge method for a DC-DC power supply maintenance module, characterized in that: A circuit applied to a DC-DC power supply maintenance module according to any one of claims 1 to 5, the method comprising: When the discharge circuit is working, the discharge inductor in the discharge circuit is used to limit the impact current generated by the energy storage capacitor at the moment of discharge to a value less than or equal to the current threshold of the discharge switch tube in the discharge circuit, so that the discharge switch tube can work safely; Obtaining a comparison of voltages between the energy storage capacitor and an input capacitor in the discharge circuit; Based on the voltage comparison, the discharge circuit is controlled to discharge using the discharge switch tube.

7. The method according to claim 6, characterized in that The voltage comparison condition includes that the voltage across the energy storage capacitor is greater than the voltage across the input capacitor; and based on the voltage comparison condition, using the discharge switch tube to control the discharge circuit to discharge, includes: When the voltage across the energy storage capacitor is greater than the voltage across the input capacitor, controlling the discharge switch tube to receive the PWM wave sent by the controller; Determining the duty cycle of the discharge switch tube based on the PWM wave; Based on the discharge switch tube and the duty cycle, the energy storage capacitor or the discharge inductor is controlled to charge the input capacitor and the DC-DC power supply, so that the discharge circuit is discharged.

8. The method according to claim 7, characterized in that The controlling the energy storage capacitor or the discharge inductor to charge the input capacitor and the DC-DC power supply based on the discharge switch tube and the duty cycle includes: Based on the duty cycle, the energy storage capacitor and the input capacitor, obtaining a current change of a discharge current flowing through the discharge inductor; When the discharge switch tube is in the on state, the energy storage capacitor is controlled to charge the input capacitor and the DC-DC power supply based on the current change; When the discharge switch tube is in the off state, the discharge inductor is controlled to charge the input capacitor and the DC-DC power supply based on the current change.

9. The method according to claim 6, characterized in that The voltage comparison condition includes that the voltage across the energy storage capacitor is equal to the voltage across the input capacitor; and based on the voltage comparison condition, using the discharge switch tube to control the discharge circuit to discharge, includes: When the voltage comparison condition is that the voltage across the energy storage capacitor is equal to the voltage across the input capacitor, the discharge switch tube is controlled to remain in the on state, and the energy storage capacitor is controlled to charge the DC-DC power supply so that the discharge circuit discharges.

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