Voltage conversion circuit and energy storage system

Abstract

The invention provides a voltage conversion circuit and an energy storage system, and the voltage conversion circuit comprises a voltage conversion module of which the input end and the output end are respectively connected with a power supply and a load; the voltage detection module is connected with the output end of the voltage conversion module; the control end and the output end of the second switch module are respectively connected with the power supply and the control end of the first switch module, the control end of the first switch module is also connected with the voltage detection module, and the output end of the first switch module is connected with the voltage conversion module; the second switch module is used for controlling on-off of the first switch module, and the on-off of the first switch module is used for controlling the charging and discharging process of the voltage conversion module to enable the output end, connected with the load, of the voltage conversion module to boost; the voltage detection module is used for detecting the voltage of the output end of the voltage conversion module, and is used for controlling the switching of the first switch module to enable the output end of the voltage conversion module to output a preset value, so as to achieve the self-excitation boost of the circuit.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic circuit technology, and in particular to a voltage conversion circuit and an energy storage system. Background Art

[0002] A flyback topology is commonly used when a boost power supply is used to power a system. However, this topology involves peripheral power components such as transformers, which not only increases material costs but also increases circuit size, hindering miniaturization.

[0003] Conventional voltage conversion circuits rely on control devices such as the CPU (Central Processing Unit) to control the switches in the voltage conversion circuit (the CPU chip sends PWM pulse signals to control the switching tubes). This not only requires professionals to write and debug programs, resulting in increased manual maintenance costs, but also complicates the circuit structure, increasing the probability of failure and the difficulty of troubleshooting.

[0004] Therefore, it is of great practical significance to explore low-cost, simple and reliable boost power supply circuit solutions. Summary of the Invention

[0005] The embodiments of the present application provide a voltage conversion circuit and an energy storage system, which can omit the CPU in the existing buck circuit and realize circuit self-excitation boost, thereby reducing costs and simplifying the circuit.

[0006] In a first aspect, an embodiment of the present application provides a voltage conversion circuit, comprising: A voltage conversion module, whose input and output terminals are used to connect to a power source and a load respectively; A voltage detection module connected to the output end of the voltage conversion module; a first switch module and a second switch module, wherein the control end and the output end of the second switch module are respectively connected to the power supply and the control end of the first switch module, the control end of the first switch module is also connected to the voltage detection module, and the output end of the first switch module is connected to the voltage conversion module; The second switch module is used to control the switch of the first switch module, and the switch of the first switch module is used to control the charging and discharging process of the voltage conversion module so as to boost the output terminal of the voltage conversion module connected to the load; The voltage detection module is used to detect the voltage at the output end of the voltage conversion module, and to control the switch of the first switch module so that the output end of the voltage conversion module outputs a preset value.

[0007] In some embodiments, the first switch module includes a switch tube Q2 and a resistor R2; the control end of the switch tube Q2 is connected to the output end of the second switch module through the resistor R2, the first end of the switch tube Q2 is connected to the voltage conversion module, and the second end of the switch tube Q2 is used to connect to the grounded negative electrode of the power supply; the second switch module is used to control the conduction and cutoff of the switch Q2.

[0008] In some embodiments, the second switch module includes a switch tube Q1, an energy storage unit and a resistor R1; the control end of the switch tube Q1 is connected to the power supply through the resistor R1, the first end of the switch tube Q1 is connected to the control end of the switch tube Q2, and the second end of the switch tube Q1 is connected to a terminal of the voltage conversion module for connecting to the power supply; the first end of the energy storage unit is connected to the control end of the switch tube Q1, and the second end of the energy storage unit is connected to the first end of the switch tube Q2 and the connection point of the voltage conversion module; when the voltage conversion module is charging and storing energy, the energy storage unit is used to charge and store energy and control the switch tube Q2 to be turned off when the charging value reaches a first value.

[0009] In some embodiments, the voltage conversion module includes an inductor L1, a diode D1 and a capacitor C3; the first end of the inductor L1 is connected to the second end of the switch tube Q1, the second end of the inductor L1 is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to the first end of the capacitor C3, the second end of the capacitor C3 is grounded, and the first and second ends of the capacitor C3 form the output end of the voltage conversion module for supplying power to the load; the first end of the switch tube Q2 is connected to the connection point between the inductor L1 and the diode D1, and the switch tube Q2 is used to turn on the power supply and the charging energy storage circuit of the inductor L1 when it is turned on; the switch tube Q2 is used to cut off the power supply and the charging energy storage circuit of the inductor L1 when it is turned off.

[0010] In some embodiments, the voltage detection module includes a voltage sampling unit and a switch tube Q3; the voltage sampling unit is connected to the output end of the voltage conversion module, and the voltage sampling unit is also connected to the control end of the switch tube Q3, the first end of the switch tube Q3 is connected to the control end of the first switch module, and the second end of the switch tube Q3 is grounded.

[0011] In some embodiments, the voltage conversion circuit further includes: a third switch module, connected in series between the power supply and the voltage conversion module; the third switch module is used to conduct the path between the power supply and the voltage conversion module when the power supply is powered on; an overcurrent detection module and a drive module, the overcurrent detection module is connected to the voltage conversion module and the drive module, and the drive module is connected to the control end of the third switch module; the overcurrent detection module is used to detect the output current of the output end of the voltage conversion module, and output an overcurrent signal to the drive module when the output current is greater than a preset current threshold; the drive module is used to output a shutdown drive signal to the control end of the third switch module based on the overcurrent signal; the third switch module is also used to disconnect the path between the power supply and the voltage conversion module when receiving the shutdown drive signal.

[0012] In some embodiments, the overcurrent detection module includes a switch tube Q4, a switch tube Q5, a resistor Rm, a resistor R3 and a diode D2; the output end of the voltage conversion module is connected to the load through the resistor Rm, the first end of the switch tube Q4 is connected to the connection between the resistor Rm and the output end of the voltage conversion module, the control end of the switch tube Q4 is connected to the connection between the resistor Rm and the load, the second end of the switch tube Q4 is connected to the positive electrode of the diode D2, the negative electrode of the diode D2 is connected to the first end of the resistor R3, the second end of the resistor R3 is connected to the control end of the switch tube Q5, the first end of the switch tube Q5 is connected to the control end of the driving module, and the second end of the switch tube Q5 is grounded.

[0013] In some embodiments, the third switch module includes a switch tube Q6, a switch tube Q7, a resistor R6, and a resistor R7; the first end of the switch tube Q6, the first end of the resistor R6, and the first end of the resistor R7 are all connected to the power supply, the second end of the switch tube Q6 is connected to the input end of the voltage conversion module, the first end of the switch tube Q7 is connected to the second end of the resistor R6, the second end of the switch tube Q7 is connected to the control end of the switch tube Q6, and the control end of the switch tube Q7 is simultaneously connected to the second end of the resistor R7 and the driving module.

[0014] In some embodiments, the driving module includes a switch tube Q8; the control end of the switch tube Q8 is connected to the overcurrent detection module, the first end of the switch tube Q8 is connected to the control end of the third switch module, and the second end of the switch tube Q8 is grounded.

[0015] In a second aspect, an embodiment of the present application provides an energy storage system, which includes the voltage conversion circuit as described above.

[0016] The present embodiment provides a voltage conversion circuit and energy storage system that periodically cycles between charging and discharging phases, ultimately stabilizing the voltage at the output (Vout) of the voltage conversion module 10 near a preset value. This embodiment provides a stable operating voltage for the load and eliminates the CPU in existing DC boost circuits, achieving self-excited boosting, thereby reducing costs and simplifying the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0018] Figure 1 This is a structural block diagram of a voltage conversion module provided in an embodiment of the present application; Figure 2 This is a structural block diagram of another voltage conversion module provided in an embodiment of the present application; Figure 3 This is a circuit structure diagram of a voltage conversion module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0020] The technical features involved in the various embodiments of the present application described below do not conflict with each other and can be combined with each other.

[0021] When an element is referred to as being “connected to” another element, it can be directly connected to the other element, or one or more intervening elements may be present therebetween.

[0022] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "first," "second," and the like generally distinguish objects of a class and do not limit the number of objects. For example, the first object may be one or more.

[0023] See also Figure 1 , Figure 1This is a structural block diagram of a voltage conversion module 10 provided in an embodiment of the present application.

[0024] An embodiment of the present application provides a voltage conversion circuit 100 , which includes a voltage conversion module 10 , a voltage detection module 20 , a first switch module 30 , and a second switch module 40 .

[0025] The input and output of the voltage conversion module 10 are respectively connected to a power supply (the power supply connection point is Vin in the figure) and a load (the load connection point is Vout in the figure). The voltage detection module 20 is connected to the output of the voltage conversion module 10. The control terminal and output of the second switch module 40 are respectively connected to the power supply and the control terminal of the first switch module 30. The control terminal of the first switch module 30 is also connected to the voltage detection module 20, and the output of the first switch module 30 is connected to the voltage conversion module 10.

[0026] Specifically, the second switch module 40 is used to control the switching of the first switch module 30. The switching of the first switch module 30 is used to control the charging and discharging process of the voltage conversion module 10 so as to boost the voltage at the output terminal of the voltage conversion module 10 connected to the load. The voltage detection module 20 is used to detect the voltage value at the output terminal of the voltage conversion module 10 connected to the load and to control the switching of the first switch module 30 so that the output terminal of the voltage conversion module 10 connected to the load outputs a preset value.

[0027] The preset value is a fixed voltage value that is pre-set and serves as a reference standard for the output voltage of the output terminal of the voltage conversion module 10. It can also be considered as a reference standard for the output voltage of the voltage conversion circuit 100. The preset value is typically determined based on factors such as the specific application requirements of the voltage conversion circuit 100, the characteristics of the voltage conversion module 10, and load requirements.

[0028] In actual application, when the power supply (Vin) is just powered on, the second switch module 40 is turned on, and then the second switch module 30 is repeatedly turned on and off. When the second switch module 40 is turned on, it outputs a high-level signal to the control end of the first switch module 30 to control the first switch module 30 to be turned on. At this time, the voltage conversion module 10 is charged; when the second switch module 40 is turned off, it outputs a low-level signal to the control end of the first switch module 30 to control the first switch module 30 to be turned off. At this time, the voltage conversion module 10 is discharged. In this way, during the switching process between the first switch module 30 and the second switch module 40, the voltage conversion module 10 is charged (for example, the inductor and capacitor therein) and provides an output voltage to the load (Vout).

[0029] Furthermore, the cooperation of the first switch module 30 and the second switch module 40 will increase the voltage of the voltage conversion module 10. In order to provide a stable voltage of a preset value to the load, the cooperation of the voltage detection module 20 is required. Specifically, when the output voltage Vout reaches or exceeds the preset value, the voltage detection module 20 outputs a shutdown signal to the control terminal of the first switch module 30 to control the first switch module 30 to shut down, thereby preventing the voltage conversion module 10 from charging and storing energy, and thus reducing the output voltage Vout. Conversely, when the output voltage Vout is less than the preset value, the voltage detection module 20 outputs a conduction signal to the control terminal of the first switch module 30 to control the first switch module 30 to conduct, thereby allowing the voltage conversion module 10 to continue charging and storing energy, and thus reducing the output voltage Vout. This process is repeated so that the output voltage Vout is ultimately delivered to the load at a stable preset value.

[0030] The shutdown signal is a signal output by the voltage detection module 20 when it detects that the output voltage (the output voltage of the output end of the voltage conversion module 10 ) is greater than a preset value.

[0031] The conduction signal is a signal output by the voltage detection module 20 when it detects that the output voltage is less than a preset value.

[0032] The embodiment of the present application provides a stable voltage to the load through the dynamic adjustment process of the first switch module 30, the second switch module 40 and the voltage detection module 20, and does not require the CPU to send a PWM pulse signal to control the conduction and cutoff of the switch tube to achieve the boost process, thereby achieving the purpose of reducing costs and simplifying the circuit.

[0033] See also Figure 2 , Figure 2 This is a structural block diagram of another voltage conversion module 10 provided in an embodiment of the present application.

[0034] In some embodiments, the voltage conversion circuit 100 further includes a third switch module 50, an overcurrent detection module 60, and a driver module 70. The third switch module 50 is connected in series between the power supply and the voltage conversion module 10. The overcurrent detection module 60 is connected to the voltage conversion module 10 and the driver module 70, and the driver module 70 is connected to the control terminal of the third switch module 50.

[0035] Specifically, the third switch module 50 is configured to connect the power supply to the voltage conversion module 10 when the power supply is powered on. The overcurrent detection module 60 is configured to detect the output current at the output terminal of the voltage conversion module 10 and output an overcurrent signal to the driver module 70 when the output current exceeds a preset current threshold. The driver module 70 is configured to output a shutdown drive signal to the control terminal of the third switch module 50 based on the overcurrent signal. The third switch module 50 is further configured to disconnect the power supply from the voltage conversion module 10 upon receiving the shutdown drive signal.

[0036] The preset current threshold is a pre-set current value that serves as a criterion for the overcurrent detection module 60 to determine whether the output current at the output terminal (Vout) of the voltage conversion module 10 is excessive. Each component in the voltage conversion circuit 100 and the load connected to it have a maximum current they can withstand. If the current exceeds this limit, it may cause component damage, circuit failure, or even lead to safety issues. The preset current threshold is determined based on the characteristics of the voltage conversion module 10, the rated currents of other components in the circuit, and the safety requirements of the entire circuit.

[0037] The overcurrent signal is a signal output by the overcurrent detection module 60 when it detects that the output current of the output end of the voltage conversion module 10 is greater than a preset current threshold.

[0038] The shutoff driving signal is a signal output by the driving module 70 , and its function is to control the third switch module 50 to shut down.

[0039] See also Figure 3 , Figure 3 Schematic diagram of the circuit structure of a voltage conversion module 10 provided in an embodiment of the present application.

[0040] In some embodiments, the second switch module 40 includes a switch tube Q1, an energy storage unit and a resistor R1. The control end of the switch tube Q1 is connected to the power supply through the resistor R1, the first end of the switch tube Q1 is connected to the control end of the switch tube Q2, and the second end of the switch tube Q1 is connected to the end of the voltage conversion module 10 for connecting to the power supply; the first end of the energy storage unit is connected to the control end of the switch tube Q1, and the second end of the energy storage unit is connected to the connection between the first end of the switch tube Q2 and the voltage conversion module 10. During the charging and energy storage process of the voltage conversion module 10, the energy storage unit is used to charge and store energy and control the switch tube Q2 to be cut off when the charging value reaches the first value. Wherein, Figure 3 As shown, the energy storage unit is a capacitor C1 , a first end of the capacitor C1 is connected to the control end of the switch tube Q1 , and a second end of the capacitor C1 is connected to a terminal of the voltage conversion module 10 for connecting to a power supply.

[0041] In actual applications, the second switching module 40 controls the on / off switching of the switch Q2 based on the charge and discharge characteristics of the capacitor C1. Specifically, the power supply provides a bias voltage to the control terminal of the switch Q1 through the resistor R1, turning on the switch Q1. After the switch Q1 turns on, the power supply voltage is transmitted through the switch Q1 to the control terminal of the switch Q2, triggering the switch Q2 to turn on and starting the charging of the voltage conversion module 10. Simultaneously, the power supply charges the capacitor C1 through the resistor R1, gradually increasing the capacitor voltage. When the voltage of the capacitor C1 reaches a first threshold (approximately equal to the power supply voltage), the voltage at the control terminal of the switch Q1 is pulled up, turning off the switch Q1. After the switch Q1 turns off, the bias voltage at the control terminal of the switch Q2 is lost, and the switch Q2 is subsequently turned off. The voltage conversion module 10 stops charging and enters the discharge phase. As the voltage conversion module 10 discharges, the capacitor C1 discharges through the resistor R1, and the voltage gradually decreases. When the voltage of the capacitor C1 falls below the first threshold, the switch Q1 turns on again, triggering the next charging cycle and forming an oscillation. This process is repeated to boost the power supply voltage, wherein the first value is Vin-VEB, where Vin is the input power supply voltage and VEB is the on-state voltage drop of the switch tube Q1.

[0042] In this embodiment, the switch Q1 is a PNP transistor. The base of the PNP transistor serves as the control terminal of the switch Q1, the emitter of the PNP transistor serves as the first terminal of the switch Q1, and the collector of the PNP transistor serves as the second terminal of the switch Q1. Alternatively, the switch Q1 may be any controllable switch, such as an insulated gate bipolar transistor (IGBT), an integrated gate-commutated thyristor (IGCT), a gate turn-off thyristor (GTO), a silicon-controlled rectifier (SCR), a junction-gate field-effect transistor (JFET), or a MOS-controlled thyristor (MCT).

[0043] In some embodiments, the first switch module 30 includes a switch Q2 and a resistor R2. The control terminal of the switch Q2 is connected to the output terminal of the second switch module via the resistor R2. The first terminal of the switch Q2 is connected to the voltage conversion module, and the second terminal of the switch Q2 is connected to the grounded negative terminal of the power supply. The second switch module is used to control the conduction and cutoff of the switch Q2. Furthermore, the first terminal of the switch Q1 is connected to the control terminal of the switch Q2 via the resistor R2.

[0044] In this embodiment, the switch Q2 is an NPN transistor. The base of the NPN transistor serves as the control terminal of the switch Q2, the collector of the NPN transistor serves as the first terminal of the switch Q2, and the emitter of the NPN transistor serves as the second terminal of the switch Q2. Alternatively, the switch Q2 may be any controllable switch, such as an insulated gate bipolar transistor (IGBT), an integrated gate-commutated thyristor (IGCT), a gate turn-off thyristor (GTO), a silicon-controlled rectifier (SCR), a junction-gate field-effect transistor (JFET), or a MOS-controlled thyristor (MCT).

[0045] In some embodiments, the voltage conversion module 10 includes an inductor L1 , a diode D1 , and a capacitor C3 .

[0046] The first end of inductor L1 is connected to the second end of switch Q1, the second end of inductor L1 is connected to the anode of diode D1, the cathode of diode D1 is connected to the first end of capacitor C3, the second end of capacitor C3 is grounded, and the first and second ends of capacitor C3 form the output end of voltage conversion module 10 that supplies power to the load. The first end of switch Q2 is connected to the junction of inductor L1 and diode D1. When switched on, switch Q2 is used to connect the power supply and the charging and energy storage circuit of inductor L1; when switched off, switch Q2 is used to disconnect the power supply and the charging and energy storage circuit of inductor L1.

[0047] In actual application, when switch Q1 is turned on and switch Q2 (first switch module 30) is turned on, the power supply, inductor L1, and switch Q2 form a charging circuit. Current flows through inductor L1, causing it to store magnetic energy. At this time, capacitor C1 is also charged. The current in inductor L1 increases linearly under the action of the power supply, gradually storing energy in inductor L1. When C1 is charged to the point where the voltage across it is approximately equal to the power supply voltage Vin, switch Q1 is turned off. This, in turn, causes switch Q2 to turn off. The sudden change in current in inductor L1 generates an induced electromotive force (EMF) with a negative voltage on the left and a positive voltage on the right. The energy stored in inductor L1 during the charging process is supplied to Vout via the freewheeling diode D1. As inductor L1 discharges, capacitor C1 also discharges until the voltage across it reaches the first value, at which point switch Q1 turns on again. This process repeats, achieving a boosted power-up process for output voltage Vout.

[0048] In some embodiments, the voltage detection module 20 includes a voltage sampling unit and a switch Q3. The voltage sampling unit is connected to the output terminal of the voltage conversion module 10 and is also connected to the control terminal of the switch Q3. The first terminal of the switch Q3 is connected to the control terminal of the first switch module 30, and the second terminal of the switch Q3 is grounded. Specifically, the first terminal of the switch Q3 is connected to the control terminal of the switch Q2 of the first switch module 30.

[0049] Among them, such as Figure 3As shown, the sampling unit includes resistors R4 and R5. A first end of resistor R4 is connected to the output terminal of voltage conversion module 10, a second end of resistor R4 is connected to a first end of resistor R5 and the control terminal of switch Q3, and a second end of resistor R5 is grounded. The preset value can be adjusted by adjusting the resistance values ​​of resistors R3 and R4.

[0050] In practical applications, resistors R4 and R5 are connected in series to form a voltage divider circuit, which is directly connected to the output of the voltage conversion module 10 (across capacitor C3). After the output voltage Vout is proportionally divided, a sampling voltage Vgs is generated across resistor R5. This voltage is linearly related to the output voltage Vout (Vgs = Vout × R5 / (R5 + R4)). When the output voltage changes, the sampling voltage changes synchronously, providing an input signal for subsequent switch control. The sampling voltage acts on the control terminal of the switch Q3 (such as the MOSFET gate). Specifically, when the output voltage is greater than a preset value, the sampling voltage reaches the turn-on voltage of the switch Q3, turning on the switch Q3 and grounding the control terminal of the first switch module 30 (low level), triggering the subsequent circuit to disconnect the energy storage circuit. When the output voltage is less than the threshold, the sampling voltage is insufficient, turning on the switch Q3. The switch Q3 is then turned off, and the control terminal of the first switch module 30 is pulled up to maintain a high level, resuming the energy storage process.

[0051] In this embodiment, the switch Q3 is an NPN transistor. The base of the NPN transistor serves as the control terminal of the switch Q3, the collector of the NPN transistor serves as the first terminal of the switch Q3, and the emitter of the NPN transistor serves as the second terminal of the switch Q3. Alternatively, the switch Q3 may be any controllable switch, such as an insulated gate bipolar transistor (IGBT), an integrated gate-commutated thyristor (IGCT), a gate turn-off thyristor (GTO), a silicon-controlled rectifier (SCR), a junction-gate field-effect transistor (JFET), or a MOS-controlled thyristor (MCT).

[0052] In some embodiments, the third switch module 50 includes a switch Q6, a switch Q7, a resistor R6, and a resistor R7. A first end of the switch Q6, a first end of the resistor R6, and a first end of the resistor R7 are all connected to a power source, a second end of the switch Q6 is connected to an input end of the voltage conversion module 10, a first end of the switch Q7 is connected to a second end of the resistor R6, and a second end of the switch Q7 is connected to a control end of the switch Q6. The control end of the switch Q7 is also connected to the second end of the resistor R7 and the driver module 70.

[0053] In some embodiments, the overcurrent detection module 60 includes a switch Q4, a switch Q5, a resistor Rm, a resistor R3, and a diode D2. The output end of the voltage conversion module 10 is connected to the load via the resistor Rm. The first end of the switch Q4 is connected to the connection between the resistor Rm and the output end of the voltage conversion module 10. The control end of the switch Q4 is connected to the connection between the resistor Rm and the load. The second end of the switch Q4 is connected to the anode of the diode D2. The cathode of the diode D2 is connected to the first end of the resistor R3. The second end of the resistor R3 is connected to the control end of the switch Q5. The first end of the switch Q5 is connected to the control end of the driver module 70. The second end of the switch Q5 is grounded.

[0054] In some embodiments, the driving module 70 includes a switch Q8 , a control terminal of which is connected to the overcurrent detection module 60 , a first terminal of which is connected to the control terminal of the third switch module 50 , and a second terminal of which is grounded.

[0055] In this embodiment, taking the switch transistor Q4 as a PNP transistor as an example, the base of the PNP transistor is the control terminal of the switch transistor Q4, the emitter of the PNP transistor is the first terminal of the switch transistor Q4, and the collector of the PNP transistor is the second terminal of the switch transistor Q4. Taking the switch transistor Q5 as an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switch transistor Q5, the collector of the NPN transistor is the first terminal of the switch transistor Q5, and the emitter of the NPN transistor is the second terminal of the switch transistor Q5. Taking the switch transistor Q6 as an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switch transistor Q6, the collector of the NPN transistor is the first terminal of the switch transistor Q6, and the emitter of the NPN transistor is the second terminal of the switch transistor Q6. Taking the switch transistor Q7 as an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switch transistor Q7, the collector of the NPN transistor is the first terminal of the switch transistor Q7, and the emitter of the NPN transistor is the second terminal of the switch transistor Q7. Taking switch Q8 as a PNP transistor as an example, the base of the PNP transistor serves as the control terminal of switch Q8, the emitter of the PNP transistor serves as the first terminal of switch Q8, and the collector of the PNP transistor serves as the second terminal of switch Q8. In addition, switches Q4, Q5, Q6, Q7, and Q8 can be any controllable switches, such as insulated gate bipolar transistors (IGBTs), integrated gate-commutated thyristors (IGCTs), gate turn-off thyristors (GTOs), silicon-controlled rectifiers (SCRs), junction-gate field-effect transistors (JFETs), and MOS-controlled thyristors (MCTs).

[0056] like Figure 3As shown, in actual application, when the current of the load (the output current of the output end of the voltage conversion module 10) is less than the preset current threshold, the switch tube Q4 is turned off, the switch tube Q5 is also turned off due to the lack of bias voltage, the switch tube Q8 of the driving module 70 is turned off, and the switch tube Q7 of the third switch module 50 is turned on, thereby driving the switch tube Q6 to turn on, and the voltage conversion module 10 operates normally. When the load current (the output current at the output end of the voltage conversion module 10) is greater than the preset current threshold, the voltage drop across the resistor Rm increases, turning on the switch tube Q4. After voltage division by the diode D2 and the resistor R3, the switch tube Q5 is triggered to turn on. The control end of the switch tube Q8 of the driving module 70 is grounded to turn it on, thereby cutting off the control signal of the third switch module 50, turning off the switch tube Q6, and disconnecting the input power of the voltage conversion module 10, thereby achieving overcurrent protection.

[0057] An embodiment of the present application further provides an energy storage system, which includes the voltage conversion circuit 100 as described above.

[0058] The specific structure and working principle of the voltage conversion circuit 100 may refer to the above embodiments and will not be described in detail here.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A voltage conversion circuit, characterized in that: include: A voltage conversion module, whose input and output terminals are used to connect to a power source and a load respectively; A voltage detection module connected to the output end of the voltage conversion module; a first switch module and a second switch module, wherein the control end and the output end of the second switch module are respectively connected to the power supply and the control end of the first switch module, the control end of the first switch module is also connected to the voltage detection module, and the output end of the first switch module is connected to the voltage conversion module; The second switch module is used to control the switch of the first switch module, and the switch of the first switch module is used to control the charging and discharging process of the voltage conversion module so as to boost the output terminal of the voltage conversion module connected to the load; The voltage detection module is used to detect the voltage of the output end of the voltage conversion module, and is used to control the switch of the first switch module so that the output end of the voltage conversion module outputs a preset value.

2. The voltage conversion circuit according to claim 1, wherein: The first switch module includes a switch tube Q2 and a resistor R2; The control end of the switch tube Q2 is connected to the output end of the second switch module through the resistor R2, the first end of the switch tube Q2 is connected to the voltage conversion module, and the second end of the switch tube Q2 is used to connect to the grounded negative electrode of the power supply; the second switch module is used to control the conduction and cutoff of the switch Q2.

3. The voltage conversion circuit according to claim 2, wherein: The second switch module includes a switch tube Q1, an energy storage unit and a resistor R1; The control end of the switch tube Q1 is connected to the power supply through the resistor R1, the first end of the switch tube Q1 is connected to the control end of the switch tube Q2, and the second end of the switch tube Q1 is connected to a terminal of the voltage conversion module for connecting to the power supply; the first end of the energy storage unit is connected to the control end of the switch tube Q1, and the second end of the energy storage unit is connected to the connection between the first end of the switch tube Q2 and the voltage conversion module; During the charging and energy storage process of the voltage conversion module, the energy storage unit is used to charge and store energy and control the switch tube Q2 to be turned off when the charging value reaches a first value.

4. The voltage conversion circuit according to claim 3, wherein: The voltage conversion module includes an inductor L1, a diode D1 and a capacitor C3; The first end of the inductor L1 is connected to the second end of the switch Q1, the second end of the inductor L1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the first end of the capacitor C3, the second end of the capacitor C3 is grounded, and the first and second ends of the capacitor C3 form the output end of the voltage conversion module for powering the load; The first end of the switch tube Q2 is connected to the connection point of the inductor L1 and the diode D1. The switch tube Q2 is used to conduct the power supply and the charging energy storage circuit of the inductor L1 when it is turned on; the switch tube Q2 is used to cut off the power supply and the charging energy storage circuit of the inductor L1 when it is turned off.

5. The voltage conversion circuit according to claim 1, wherein: The voltage detection module includes a voltage sampling unit and a switch tube Q3; The voltage sampling unit is connected to the output end of the voltage conversion module. The voltage sampling unit is also connected to the control end of the switch tube Q3. The first end of the switch tube Q3 is connected to the control end of the first switch module, and the second end of the switch tube Q3 is grounded.

6. The voltage conversion circuit according to claim 1, wherein: The voltage conversion circuit further includes: a third switch module connected in series between the power supply and the voltage conversion module; the third switch module is used to conduct a path between the power supply and the voltage conversion module when the power supply is powered on; an overcurrent detection module and a driving module, wherein the overcurrent detection module is connected to the voltage conversion module and the driving module, and the driving module is connected to the control end of the third switch module; the overcurrent detection module is used to detect the output current of the output end of the voltage conversion module, and output an overcurrent signal to the driving module when the output current is greater than a preset current threshold; the driving module is used to output a shutdown driving signal to the control end of the third switch module based on the overcurrent signal; the third switch module is further used to disconnect the path between the power supply and the voltage conversion module when receiving the shutdown driving signal.

7. The voltage conversion circuit according to claim 6, wherein: The overcurrent detection module includes a switch tube Q4, a switch tube Q5, a resistor Rm, a resistor R3 and a diode D2; The output end of the voltage conversion module is connected to the load through the resistor Rm, the first end of the switch tube Q4 is connected to the connection between the resistor Rm and the output end of the voltage conversion module, the control end of the switch tube Q4 is connected to the connection between the resistor Rm and the load, the second end of the switch tube Q4 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the first end of the resistor R3, the second end of the resistor R3 is connected to the control end of the switch tube Q5, the first end of the switch tube Q5 is connected to the control end of the driving module, and the second end of the switch tube Q5 is grounded.

8. The voltage conversion circuit according to claim 6, wherein: The third switch module includes a switch tube Q6, a switch tube Q7, a resistor R6 and a resistor R7; The first end of the switch tube Q6, the first end of the resistor R6, and the first end of the resistor R7 are all connected to the power supply, the second end of the switch tube Q6 is connected to the input end of the voltage conversion module, the first end of the switch tube Q7 is connected to the second end of the resistor R6, the second end of the switch tube Q7 is connected to the control end of the switch tube Q6, and the control end of the switch tube Q7 is also connected to the second end of the resistor R7 and the driving module.

9. The voltage conversion circuit according to claim 6, wherein: The driving module includes a switch tube Q8; The control end of the switch tube Q8 is connected to the overcurrent detection module, the first end of the switch tube Q8 is connected to the control end of the third switch module, and the second end of the switch tube Q8 is grounded.

10. An energy storage system, characterized in that: The energy storage system includes the voltage conversion circuit according to any one of claims 1 to 9.

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