An overcurrent protection power circuit and a power management system

Abstract

The utility model provides a kind of overcurrent protection power circuit and power management system, comprising: boost-buck conversion module, including first ground terminal, standby voltage output end and power voltage input end;Overcurrent protection module, including second ground terminal, driving voltage output end, load voltage input end, with the standby voltage input end of standby voltage output end connection;Power drive module, including with the driving voltage input end of driving voltage output end connection, with the load voltage output end of load voltage input end connection, with the load connection end of external load connection;In overcurrent protection module, the voltage value of load voltage input end is used to control the output of driving voltage output end.The utility model improves traditional power circuit, can dynamically adjust the circuit of output power according to demand, avoid the situation of driving circuit overcurrent damage at the same time, improve the security, stability and fast reactivity of system work.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and in particular to an overcurrent protection power circuit and a power management system. Background Technology

[0002] In modern electronic power systems, multiple transistors are typically used to form a bridge circuit to generate alternating current to drive the motor of an external load. Examples include H-bridge power circuits, half-bridge power circuits, and three-phase full-bridge power circuits. These bridge circuits are widely used in switching power supplies, inverters, motor drives, and other fields.

[0003] In diverse application scenarios, different power drive specifications are required. Applications such as electric vehicle drives, industrial frequency converters, and renewable energy inverters generally require high voltage or high current for high-power driving. Applications such as mobile phone chargers, power supplies for small electronic devices, and audio signal processing circuits generally require low voltage and low current to suit low-power driving scenarios. However, current bridge drive circuits typically use high-voltage power supplies directly, resulting in higher product costs and power waste in low-power driving scenarios. Furthermore, when the external load exceeds the circuit's driving capacity, current bridge drive circuits typically cannot adjust the circuit or shut off the power according to the load conditions, preventing damage to the entire circuit. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this utility model provides an overcurrent protection power circuit, which solves the problems of existing bridge drive circuits directly using high-voltage power supplies, resulting in high product costs, power waste in low-power drive scenarios, and easy circuit damage.

[0005] According to an embodiment of the present invention, a first aspect provides an overcurrent protection power circuit, comprising:

[0006] The step-up / step-down converter module includes a first ground terminal, a standby voltage output terminal, and a power supply voltage input terminal;

[0007] The overcurrent protection module includes a second ground terminal, a drive voltage output terminal, a load voltage input terminal, and a standby voltage input terminal connected to the standby voltage output terminal;

[0008] The power drive module includes a drive voltage input terminal connected to the drive voltage output terminal, a load voltage output terminal connected to the load voltage input terminal, and a load connection terminal connected to an external load.

[0009] In the overcurrent protection module, the output of the drive voltage output terminal is controlled according to the voltage value of the load voltage input terminal. When the output of the drive voltage output terminal is 0, the power drive module stops working.

[0010] Optionally, the overcurrent protection module includes a comparator, a first resistor, a second resistor, a third resistor, a fourth resistor, a switching transistor, and a first field-effect transistor;

[0011] The negative input terminal of the comparator is the load voltage input terminal. The negative input terminal of the comparator is connected to one end of the first resistor, and the other end of the first resistor is the second ground terminal. The positive input terminal of the comparator is connected to one end of the second resistor, and the other end of the second resistor is grounded. One end of the third resistor is connected to the positive input terminal of the comparator and one end of the second resistor, and the other end of the third resistor is connected to the output terminal of the comparator. The output terminal of the comparator is connected to the base of the switching transistor. The emitter of the switching transistor is connected to the source of the first field-effect transistor. The collector of the switching transistor is connected to the gate of the first field-effect transistor. The drain of the first field-effect transistor is the standby voltage input terminal. The gate of the first field-effect transistor is also connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the rated voltage.

[0012] Optionally, the switching transistor is an NPN transistor, and the first field-effect transistor is an N-channel enhancement-mode field-effect transistor.

[0013] Optionally, the rated voltage is greater than the voltage value at the standby voltage output terminal.

[0014] Optionally, the buck-boost converter module includes a first capacitor, a second capacitor, a first inductor, a diode, and a second field-effect transistor;

[0015] One end of the first capacitor, one end of the second field-effect transistor, and one end of the second capacitor are grounded. The other end of the first capacitor is connected to one end of the first inductor and serves as the power supply voltage input terminal, which is connected to a fixed power supply voltage. The other end of the first inductor is connected to the other end of the second field-effect transistor and the input terminal of the diode. The output terminal of the diode is connected to the other end of the second capacitor and serves as the standby voltage output terminal.

[0016] Optionally, the second field-effect transistor is an N-channel enhancement-mode field-effect transistor.

[0017] Optionally, the power drive module includes any one of an H-bridge power circuit, a half-bridge power circuit, and a three-phase full-bridge power circuit.

[0018] Optionally, the power drive module includes a third field-effect transistor, a fourth field-effect transistor, a fifth field-effect transistor, a sixth field-effect transistor, a seventh field-effect transistor, and an eighth field-effect transistor; the external load connected to the power drive module includes a first port, a second port, and a third port;

[0019] One end of the third, fifth, and seventh field-effect transistors is connected to a fixed power supply voltage. One end of the fourth, sixth, and eighth field-effect transistors is connected to and serves as the port voltage output terminal. The other end of the third field-effect transistor is connected to the other end of the fourth field-effect transistor as a load connection terminal and is connected to the first port. The other end of the fifth field-effect transistor is connected to the other end of the sixth field-effect transistor as a load connection terminal and is connected to the second port. The other end of the seventh field-effect transistor is connected to the other end of the eighth field-effect transistor as a load connection terminal and is connected to the third port.

[0020] Optionally, the third, fourth, fifth, sixth, seventh, and eighth field-effect transistors are all N-channel enhancement-mode field-effect transistors.

[0021] The second aspect provides a power management system for driving an external load and includes the overcurrent protection power circuit described above.

[0022] The technical principle of this utility model is as follows: the buck-boost converter module provides an adjustable voltage, the overcurrent protection module determines whether there is an overcurrent in the power drive module, and when the external load exceeds the driving capacity of its own circuit, it disconnects the electrical connection between the buck-boost converter module and the power drive module in time to protect the power drive module.

[0023] Compared with existing technologies, this utility model improves the power circuit based on the buck-boost converter module and the overcurrent protection module, enabling the circuit to dynamically adjust the output power according to the demand, while avoiding overcurrent damage to the drive circuit, thus improving the safety, stability and fast response of the system. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the overcurrent protection power circuit according to an embodiment of the present invention;

[0025] Figure 2 This is a circuit structure diagram of the overcurrent protection power circuit according to an embodiment of the present invention;

[0026] Figure 3 For based on Figure 2 A schematic diagram of the current flow direction;

[0027] Figure 4 For based on Figure 2 A schematic diagram of the current flow direction;

[0028] Figure 5 For based on Figure 2 A schematic diagram of the current flow direction;

[0029] Figure 6 For based on Figure 2 A schematic diagram of the current flow direction;

[0030] Figure 7 For based on Figure 2 A schematic diagram of the current flow direction;

[0031] Figure 8 For based on Figure 2 A schematic diagram of the current flow direction;

[0032] Figure 9 For based on Figure 2 A schematic diagram of an equivalent circuit.

[0033] Figure descriptions: 100, Overcurrent protection power circuit; 10, Buck-Boost converter module; 11, First ground terminal; 12, Standby voltage output terminal; 13, Power supply voltage input terminal; 20, Overcurrent protection module; 21, Second ground terminal; 22, Drive voltage output terminal; 23, Load voltage input terminal; 30, Power drive module; 31, Drive voltage input terminal; 32, Standby voltage input terminal; 33, Load connection terminal; 40, External load. Detailed Implementation

[0034] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0035] like Figure 1 As shown in the figure, this utility model embodiment proposes an overcurrent protection power circuit 100, including a buck-boost converter module 10, an overcurrent protection module 20, and a power drive module 30. The buck-boost converter module 10 provides an adjustable voltage. The overcurrent protection module 20 determines whether the power drive module 30 experiences overcurrent, specifically whether the power drive module 30's drive of its connected external load 40 exceeds its own circuit driving capacity. Furthermore, in the event of an overcurrent, the overcurrent protection power circuit 100 of this utility model embodiment promptly disconnects the electrical connection between the buck-boost converter module 10 and the power drive module 30, protecting the power drive module 30.

[0036] This embodiment of the invention illustrates the port connection relationships of each module and describes the circuit structure of the overcurrent protection power circuit 100. The buck-boost converter module 10 includes a first ground terminal 11, a standby voltage output terminal 12, and a power supply voltage input terminal 13. The overcurrent protection module 20 includes a second ground terminal 21, a drive voltage output terminal 22, a load voltage input terminal 23, and a standby voltage input terminal 24, with the standby voltage input terminal 24 connected to the standby voltage output terminal 12. The power drive module 30 includes a drive voltage input terminal 31, a load voltage output terminal 32, and a load connection terminal 33; the drive voltage input terminal 31 is connected to the drive voltage output terminal 22, the load voltage output terminal 32 is connected to the load voltage input terminal 23, and the load connection terminal 33 is connected to an external load 40.

[0037] The load voltage input terminal 23 of the overcurrent protection module 20 is connected to the load voltage output terminal 32 of the power drive module 30, so that the overcurrent condition of the power drive module 30 can be determined based on the voltage value of the load voltage input terminal 23. For example, if an overcurrent condition exists, the output of the drive voltage output terminal 22 in the overcurrent protection module 20 will be 0, and the drive voltage input terminal 31 of the power drive module 30 will not be able to receive the working voltage or working current, thereby stopping its operation and preventing damage to the overall circuit.

[0038] Based on this, the present invention improves the traditional power circuit by using a buck-boost converter module and an overcurrent protection module, enabling the circuit to dynamically adjust the output power according to demand, while avoiding overcurrent damage to the drive circuit, thus improving the safety, stability and fast response of the system.

[0039] like Figure 2 As shown in the figure, the detailed circuit structure of each of the above modules is illustrated in this embodiment of the utility model. Figure 2In the overcurrent protection module 20, there are comparator U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a switching transistor Q1, and a first field-effect transistor M1. The negative input terminal of comparator U1 is the load voltage input terminal 23, and is connected to one end of the first resistor R1, the other end of which is the second ground terminal 21. The positive input terminal of comparator U1 is connected to one end of the second resistor R2, the other end of which is grounded. One end of the third resistor R3 is connected to the positive input terminal of comparator U1 and the other end of the second resistor R2. The third resistor R3 is connected to the output of comparator U1. The output of comparator U1 is connected to the base of switching transistor Q1. The emitter of switching transistor Q1 is connected to the source of first field-effect transistor M1. The collector of switching transistor Q1 is connected to the gate of first field-effect transistor M1. The drain of first field-effect transistor M1 is the standby voltage input terminal 24. The gate of first field-effect transistor M1 is also connected to one end of fourth resistor R4. The other end of fourth resistor R4 is connected to the rated voltage VDD. For example, the supply voltage of comparator U1 is also the rated voltage VDD. In a preferred implementation, switching transistor Q1 is an NPN transistor, and first field-effect transistor M1 is an N-channel enhancement-mode field-effect transistor. In a preferred implementation, the rated voltage VDD is greater than the voltage value of standby voltage output terminal 12, that is, greater than the voltage value provided by buck-boost converter module 10.

[0040] For example Figure 2 The overcurrent protection module 20 shown works as follows: the first resistor R1 is a current-sensing resistor. The comparator U1 detects the loop current in the power drive module 30, i.e., the operating current, based on the first resistor R1, to determine whether there is an overcurrent in the power drive module 30, and introduces overcurrent protection function in case of overcurrent breakdown. For example, if the operating current of the power drive module 30 is higher than the threshold current, the comparator U1 outputs a high-level signal to the switching transistor Q1. When the base of the switching transistor Q1 receives the high-level signal, the switching transistor Q1 is turned on, the gate and source of the first field-effect transistor M1 are short-circuited, i.e., VGS=0, the first field-effect transistor M1 is turned off, the collector voltage of the switching transistor Q1 and the source voltage of the first field-effect transistor M1 are 0, i.e., the output of the aforementioned drive voltage output terminal 22 is 0, the drive voltage input terminal 31 of the power drive module 30 cannot be connected to the operating voltage or operating current, and stops working, thereby realizing overcurrent protection. For example, when the current in the circuit is within the threshold range, the comparator U1 outputs a low-level signal, the switching transistor Q1 is turned off, and the first field-effect transistor M1 remains normally open under the action of a rated voltage such as +10V. The driving voltage input terminal 31 of the power drive module 30 is connected to the working voltage or working current, and it works normally.

[0041] It should be noted that the rated voltage in the above embodiment is +10V, which means that the voltage value of the standby voltage output terminal 12 is less than 10V. That is, the buck-boost converter module 10 boosts the voltage based on the fixed power supply voltage VCC, and the final voltage value provided is less than 10V.

[0042] Figure 2 In this embodiment, the buck-boost converter module 10 includes a first capacitor C1, a second capacitor C2, a first inductor L1, a diode D1, and a second field-effect transistor M2. One end of the first capacitor C1, one end of the second field-effect transistor M2, and one end of the second capacitor C2 are grounded. The other end of the first capacitor C1 and one end of the first inductor L1 are connected to the power supply voltage input terminal 13, which is a fixed power supply voltage VCC. The other end of the first inductor L1 is connected to the other end of the second field-effect transistor M2 and the input terminal of the diode D1. The output terminal of the diode D1 is connected to the other end of the second capacitor C2, which serves as the standby voltage output terminal 12. In a preferred implementation, the second field-effect transistor M2 is an N-channel enhancement-mode field-effect transistor.

[0043] For example Figure 2 The buck-boost converter module 10 shown operates as follows: A PWM signal is applied to the second field-effect transistor M2. When the second field-effect transistor M2 is turned on, the fixed power supply voltage VCC charges the first inductor L1 and the second capacitor C2, and the voltage is also applied to the subsequent power drive module 30 and the load. When the second field-effect transistor M2 is turned off, the first inductor L1 and the second capacitor C2 discharge, and the voltage increases after being superimposed with the fixed power supply voltage VCC. At this time, if the PWM duty cycle of the second field-effect transistor M2 is increased, the voltage output at the standby voltage output terminal 12 increases accordingly; if the PWM duty cycle of the second field-effect transistor M2 is decreased, the voltage output at the standby voltage output terminal 12 decreases accordingly, thereby providing an adjustable voltage through the buck-boost converter module 10.

[0044] In this embodiment of the invention, the power drive module 30 can be any one of an H-bridge power circuit, a half-bridge power circuit, or a three-phase full-bridge power circuit. And based on... Figure 2The detailed circuit structure of the power drive module 30, which is a three-phase full-bridge power circuit, is described below. The power drive module 30 includes a third field-effect transistor M3, a fourth field-effect transistor M4, a fifth field-effect transistor M5, a sixth field-effect transistor M6, a seventh field-effect transistor M7, and an eighth field-effect transistor M8. The external load 40 connected to the load connection terminal 33 includes a first port, a second port, and a third port. One end of the third field-effect transistor M3, the fifth field-effect transistor M5, and the seventh field-effect transistor M7 is connected to VCC. One end of the fourth field-effect transistor M4, the sixth field-effect transistor M6, and the eighth field-effect transistor M8 are connected to and serve as the port voltage output terminals. The other end of the third field-effect transistor M3 is connected to the other end of the fourth field-effect transistor M4 and is connected to the first port. The other end of the fifth field-effect transistor M5 is connected to the other end of the sixth field-effect transistor M6 and is connected to the second port. The other end of the seventh field-effect transistor M7 is connected to the other end of the eighth field-effect transistor M8 and is connected to the third port. In a better implementation, the third field-effect transistor M3, the fourth field-effect transistor M4, the fifth field-effect transistor M5, the sixth field-effect transistor M6, the seventh field-effect transistor M7, and the eighth field-effect transistor M8 are all N-channel enhancement-mode field-effect transistors.

[0045] based on Figure 2 The overcurrent protection power circuit 100 shown in this embodiment of the invention also provides... Figures 3 to 9 The overcurrent protection power circuit 100 of the power drive module 30 during normal operation and the overcurrent protection power circuit 100 when the power drive module 30 has an overcurrent problem are explained. Figures 3 to 9 In this example, the external load includes a second inductor, a third inductor, a fourth inductor, a fifth resistor, a sixth resistor, and a seventh resistor.

[0046] When the power drive module 30 is operating normally, i.e., when there is no overcurrent, the current loop in the overcurrent protection power circuit 100 can be divided according to the current direction in the target load connected to the power drive module 30 and the conduction state of the second field-effect transistor M2 in the buck-boost converter module 10. For example, when the second field-effect transistor M2 in the buck-boost converter module 10 is turned on, the fixed power supply voltage VCC charges the first inductor L1 and the second capacitor C2, and the current flow direction in the overcurrent protection power circuit 100 can be as follows: Figure 3 , Figure 4 and Figure 5 As shown, for the buck-boost converter module 10, Figure 3 , Figure 4 and Figure 5 As shown, the voltage and current supplied by VCC pass through the second field-effect transistor M2, the first inductor L1, and the second capacitor C2; for the three-phase full-bridge power circuit section, Figure 3In the process, the source current of the seventh field-effect transistor M7 of the power drive module 30 is output to the seventh resistor R7 and the fourth inductor L4, and flows to the second inductor L2 and the fifth resistor R5. One end of the fifth resistor R5 outputs current to the drain of the fourth field-effect transistor M4 of the power drive module 30. Finally, the source current of the fourth field-effect transistor M4 outputs current to the first resistor R1, so that the overcurrent protection module 20 can detect the operating current of the power drive module 30. Figure 4 In the process, the source current of the fifth field-effect transistor M5 of the power drive module 30 is output to the sixth resistor R6 and the third inductor L3, and flows to the fourth inductor L4 and the seventh resistor R7. One end of the seventh resistor R7 outputs current to the drain of the eighth field-effect transistor M8 of the power drive module 30. Finally, the source current of the eighth field-effect transistor M8 is output to the first resistor R1, so that the overcurrent protection module 20 can detect the operating current of the power drive module 30. Figure 5 In the power drive module 30, the source current of the fifth MOSFET M5 outputs to the sixth resistor R6 and the third inductor L3, and then flows to the fourth inductor L4 and the seventh resistor R7. One end of the seventh resistor R7 outputs current to the drain of the eighth MOSFET M8 in the power drive module 30. Finally, the source current of the eighth MOSFET M8 outputs current to the first resistor R1, so that the overcurrent protection module 20 can detect the operating current of the power drive module 30. In the buck-boost converter module 10, the second MOSFET M2 is turned off, the first inductor L1 and the second capacitor C2 discharge, and the current flow direction of the overcurrent protection power circuit 100 can be as follows: Figure 6 , Figure 7 and Figure 8 As shown. For buck-boost converter module 10, Figure 6 , Figure 7 and Figure 8 Both show the discharge of the first inductor L1 and the second capacitor C2; while Figure 6 , Figure 7 and Figure 8 The three-phase full-bridge power circuit shown is related to Figure 3 , Figure 4 and Figure 5 The same applies, so I will not repeat it here.

[0047] When an overcurrent condition occurs in the power drive module 30, the overcurrent protection module 20 directly disconnects the electrical connection between the buck-boost converter module 10 and the power drive module 30. The current loop in the overcurrent protection power circuit 100 is divided according to the conduction state of the second field-effect transistor M2 in the buck-boost converter module 10. For example, Figure 9 As shown is the equivalent circuit diagram. In the buck-boost converter module 10, the second MOSFET M2 is turned on, and the current flows to ground through the inductor, bypassing the power drive module 30 and the target load. However, when the second MOSFET M2 is turned off in the buck-boost converter module 10, there is no working loop in the entire circuit; therefore, the equivalent circuit diagram is not shown here.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An overcurrent protection power circuit, characterized in that, include: The step-up / step-down converter module includes a first ground terminal, a standby voltage output terminal, and a power supply voltage input terminal; The overcurrent protection module includes a second ground terminal, a drive voltage output terminal, a load voltage input terminal, and a standby voltage input terminal connected to the standby voltage output terminal; The power drive module includes a drive voltage input terminal connected to the drive voltage output terminal, a load voltage output terminal connected to the load voltage input terminal, and a load connection terminal connected to an external load. In the overcurrent protection module, the output of the drive voltage output terminal is controlled according to the voltage value of the load voltage input terminal. When the output of the drive voltage output terminal is 0, the power drive module stops working.

2. The overcurrent protection power circuit as described in claim 1, characterized in that, The overcurrent protection module includes a comparator, a first resistor, a second resistor, a third resistor, a fourth resistor, a switching transistor, and a first field-effect transistor; The negative input terminal of the comparator is the load voltage input terminal. The negative input terminal of the comparator is connected to one end of the first resistor, and the other end of the first resistor is the second ground terminal. The positive input terminal of the comparator is connected to one end of the second resistor, and the other end of the second resistor is grounded. One end of the third resistor is connected to the positive input terminal of the comparator and one end of the second resistor, and the other end of the third resistor is connected to the output terminal of the comparator. The output terminal of the comparator is connected to the base of the switching transistor. The emitter of the switching transistor is connected to the source of the first field-effect transistor. The collector of the switching transistor is connected to the gate of the first field-effect transistor. The drain of the first field-effect transistor is the standby voltage input terminal. The gate of the first field-effect transistor is also connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the rated voltage.

3. The overcurrent protection power circuit as described in claim 2, characterized in that, The switching transistor is an NPN transistor, and the first field-effect transistor is an N-channel enhancement-mode field-effect transistor.

4. The overcurrent protection power circuit as described in claim 2, characterized in that, The rated voltage is greater than the voltage value at the standby voltage output terminal.

5. The overcurrent protection power circuit as described in claim 1, characterized in that, The buck-boost converter module includes a first capacitor, a second capacitor, a first inductor, a diode, and a second field-effect transistor; One end of the first capacitor, one end of the second field-effect transistor, and one end of the second capacitor are grounded. The other end of the first capacitor is connected to one end of the first inductor and serves as the power supply voltage input terminal. The power supply voltage input terminal is connected to a fixed power supply voltage. The other end of the first inductor is connected to the other end of the second field-effect transistor and the input terminal of the diode, and the output terminal of the diode is connected to the other end of the second capacitor and serves as the standby voltage output terminal.

6. The overcurrent protection power circuit as described in claim 5, characterized in that, The second field-effect transistor is an N-channel enhancement-mode field-effect transistor.

7. The overcurrent protection power circuit as described in claim 6, characterized in that, The power drive module includes any one of an H-bridge power circuit, a half-bridge power circuit, or a three-phase full-bridge power circuit.

8. The overcurrent protection power circuit as described in claim 1, characterized in that, The power drive module includes a third field-effect transistor, a fourth field-effect transistor, a fifth field-effect transistor, a sixth field-effect transistor, a seventh field-effect transistor, and an eighth field-effect transistor; the external load connected to the power drive module includes a first port, a second port, and a third port; One end of the third, fifth, and seventh field-effect transistors is connected to a fixed power supply voltage. One end of the fourth, sixth, and eighth field-effect transistors is connected to and serves as the port voltage output terminal. The other end of the third field-effect transistor is connected to the other end of the fourth field-effect transistor as a load connection terminal and is connected to the first port. The other end of the fifth field-effect transistor is connected to the other end of the sixth field-effect transistor as a load connection terminal and is connected to the second port. The other end of the seventh field-effect transistor is connected to the other end of the eighth field-effect transistor as a load connection terminal and is connected to the third port.

9. The overcurrent protection power circuit as described in claim 8, characterized in that, The third, fourth, fifth, sixth, seventh, and eighth field-effect transistors are all N-channel enhancement-mode field-effect transistors.

10. A power management system, characterized in that, For driving an external load, and includes an overcurrent protection power circuit as described in any one of claims 1 to 9.

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