Protection circuit and energy storage power supply thereof

Abstract

The embodiment of the utility model discloses a protection circuit and an energy storage power supply thereof. The circuit comprises a power supply switch module, a fuse, an energy storage module and a protection switching module. The power supply switch module is connected with an input power supply through a fuse, the power supply switch module is further connected with a load, the energy storage module is connected with the protection switching module and the power supply switch module, and the protection switching module is further connected with the fuse; the protection switching module is used for acting when the power supply switch module has a bonding fault, so that the energy storage module generates fusing current through discharging, and then the fuse is fused. According to the embodiment of the utility model, when the input relay breaks down, the protection switching module makes a quick response, so that the energy storage module generates the fusing current through discharging, thereby cutting off the fault input relay loop in time, and avoiding the potential safety hazard caused by the adhesion of the input relay in the charging circuit.

Description

TECHNICAL FIELD

[0001] The utility model embodiment relates to photovoltaic field, in particular to a protection circuit and energy storage power supply thereof. BACKGROUND

[0002] With the increasing number of RV owners, the application demand for batteries becomes various, and those who often go outdoors are used to charging RV batteries with PV photovoltaic panels.

[0003] If the input relay of the previous PV circuit using BOOST topology is stuck, the input voltage will directly charge the output battery through the freewheeling tube, which is uncontrollable and will cause a series of problems, such as continuous overcharging of the battery, and terrible safety hazards. The traditional solution is to add a controllable switch at the output end to achieve double protection, but this will increase the cost and loss, and cause unnecessary heat dissipation and cost pressure.

[0004] Similarly, if a battery-to-battery BUCK charging circuit is used, the output end can also use this circuit to avoid the output relay and MOS tube fault short circuit, so that the output end energy is poured into the input battery, thereby causing various safety risks. INVENTION CONTENTS

[0005] The technical problem solved by the embodiment of the utility model is to provide a protection circuit and energy storage power supply, which can solve some problems existing in the existing PV circuit.

[0006] To solve the above technical problems, one technical scheme of the utility model is to provide a protection circuit, comprising: a power supply switch module, a fuse, an energy storage module, and a protection switching module; the power supply switch module is connected with an input power supply through the fuse, the power supply switch module is also connected with a load, the energy storage module is connected with the protection switching module and the power supply switch module, and the protection switching module is also connected with the fuse; the protection switching module is used to act when the power supply switch module appears sticking fault, so that the energy storage module generates a fuse current through discharge, and then fuses the fuse.

[0007] In some embodiments, the protection switching module is used to act when the power supply switch module appears sticking fault, so that the energy storage module discharges through the protection switching module, the fuse and the power supply switch module, to generate the fuse current.

[0008] In some embodiments, the protection switching module comprises a switch tube Q4 and a switch tube Q5, a first end of the fuse is connected with an input end of the power supply switching module, a source of the switch tube Q4 is connected with a second end of the fuse, a drain of the switch tube Q4 is connected with a first end of the energy storage module, a source of the switch tube Q5 is connected with a second end of the energy storage module, a drain of the switch tube Q5 is connected with an output end of the power supply switching module, a gate of the switch tube Q4 is connected with a gate of the switch tube Q5 and a controller.

[0009] In some embodiments, the energy storage module comprises a capacitor CE1 and a capacitor CE2, a positive pole of the capacitor CE1 is connected with a positive pole of the capacitor CE2, an output end of the power supply switching module and a first end of the protection switching module, a second end of the capacitor CE1, a second end of the capacitor CE2 and a second end of the protection switching module are grounded.

[0010] In some embodiments, the power supply switching module comprises an input relay RLY2 and a second driving unit, an input end of the input relay RLY2 is connected with the input power supply through the fuse, an output end of the input relay RLY2 is connected with the load, a control end of the input relay RLY2 is connected with the second driving unit.

[0011] In some embodiments, the protection circuit further comprises a pre-charge module, the pre-charge module is connected with the energy storage module and the input power supply; the pre-charge module is used for pre-charging the energy storage module in response to the input power supply.

[0012] In some embodiments, the pre-charge module comprises an input relay RLY1, a pre-charge resistor RT1, a diode D1, a switch tube Q2 and a first driving unit, an input end of the input relay RLY1 is connected with an input end of the input relay RLY2, an output end of the input relay RLY1 is connected with a first end of the pre-charge resistor RT1, a second end of the pre-charge resistor RT1 is connected with a source of the switch tube Q2 and an output end of the input relay RLY2, a drain of the switch tube Q2 is connected with the energy storage module, a gate of the switch tube Q2 is connected with a controller, a first control end of the input relay RLY1 is connected with the first driving unit and an anode of the diode D1, a cathode of the diode D1 is connected with a second control end of the input relay RLY1 and a driving power supply.

[0013] In some embodiments, the pre-charging module comprises a pre-charging resistor RT1 and a switch tube Q2, a first end of the pre-charging resistor RT1 is connected with a source of the switch tube Q2 and an output end of the input relay RLY2, a second end of the pre-charging resistor RT1 is connected with a drain of the switch tube Q2 and the energy storage module, and a gate of the switch tube Q2 is connected with the controller.

[0014] In some embodiments, the protection circuit further comprises a switch tube Q3, an inductor LD1 and a capacitor CE3, the power supply switching module comprises a switch tube Q1, a source of the switch tube Q3 is connected with the load through the fuse, a drain of the switch tube Q3 is connected with a first end of the inductor LD1 and a positive pole of the capacitor CE3, a second end of the inductor LD1 is connected with a source of the switch tube Q1, a drain of the switch tube Q1 is connected with the input power supply, a gate of the switch tube Q1 is connected with a gate of the switch tube Q3 and the controller, the pre-charging module comprises a pre-charging resistor RT1 and a switch tube Q2, a first end of the pre-charging resistor RT1 is connected with a source of the switch tube Q2 and a drain of the switch tube Q1, a second end of the pre-charging resistor RT1 is connected with a drain of the switch tube Q2 and the energy storage module, and a gate of the switch tube Q2 is connected with the controller.

[0015] To solve the above technical problems, the utility model adopts another technical scheme, which provides an energy storage power supply, which comprises the protection circuit as claimed in the preceding claims.

[0016] The utility model discloses an embodiment has the advantages that, different from the prior art, when the input relay fails, the protection switching module responds quickly to make the energy storage module generate a fuse current through discharging, thereby timely cutting off the fault input relay circuit, and the safety hazard caused by the input relay sticking of the charging circuit is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structure schematic diagram of a protection circuit provided by the utility model embodiment;

[0018] Figure 2 is a structure schematic diagram of another protection circuit provided by the utility model embodiment;

[0019] Figure 3 is a circuit principle diagram of a protection circuit provided by the utility model embodiment;

[0020] Figure 4 is a circuit principle diagram of a first driving unit provided by the utility model embodiment;

[0021] Figure 5is a circuit principle diagram of a second driving unit provided by the embodiment of the utility model;

[0022] Figure 6 is a circuit principle diagram of another protection circuit provided by the embodiment of the utility model;

[0023] Figure 7 is a circuit principle diagram of still another protection circuit provided by the embodiment of the utility model. DETAILED DESCRIPTION

[0024] In order to facilitate understanding of the utility model, the utility model will be explained in more detail below in connection with the drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element or one or more intervening elements can be present therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element or one or more intervening elements can be present therebetween. The terms "vertical", "horizontal", "left", "right" and similar expressions used in the specification are only for the purpose of illustration.

[0025] Unless otherwise defined, all technical and scientific terms used in the specification are the same as the meanings commonly understood by those skilled in the art to which the utility model belongs. The terms used in the specification of the utility model are only for the purpose of describing the specific embodiments and are not used to limit the utility model. The term "and / or" used in the specification includes any and all combinations of one or more related listed items.

[0026] In some embodiments of the present application, a protection circuit is provided, and a structural schematic diagram thereof is shown in Figure 1 The protection circuit provided by the embodiment includes a power supply switch module 110, a fuse F1, an energy storage module 120 and a protection switching module 130. The power supply switch module 110 is connected to the input power supply 20 through the fuse F1, and the power supply switch module 110 is also connected to the load 30. The energy storage module 120 is connected to the protection switching module 130 and the power supply switch module 110, and the protection switching module 130 is also connected to the fuse F1. The protection switching module 130 is used to act when the power supply switch module 110 appears to be stuck, so that the energy storage module 120 generates a fuse current through discharge, and then the fuse F1 is fused.

[0027] In this embodiment, the power supply switch module 110 serves as the main control switch unit of the entire protection circuit, and is responsible for transmitting the input power supply 20 to the load 30 to supply power to the load 30. The power supply switch module 110 includes a relay and a corresponding driving unit, and the contacts of the relay are connected between the input power supply 20 and the load 30. By controlling the conduction and disconnection of the relay, the power supply control of the load 30 is realized.

[0028] The fuse F1 is connected in series between the input power supply 20 and the power supply switch module 110. When an abnormally large current appears in the circuit, the fuse F1 is blown to cut off the circuit. As an example but not limitation, the fuse F1 can be a fast blow type fuse, and the rated current can be selected according to the actual application scenario.

[0029] The energy storage module 120 includes a capacitor bank for storing electrical energy. The energy storage module 120 is connected in parallel with the power supply switch module 110, and stores energy during normal operation. As an example but not limitation, the energy storage module 120 can use a large-capacity electrolytic capacitor, and the capacitance can be selected according to the actual required discharge energy.

[0030] The protection switching module 130 includes a switching device for controlling the rapid discharge of the energy storage module 120 when a failure of the power supply switch module 110 is detected. Further explanation, if the power supply switch module appears to be stuck in failure, that is, the power supply switch module is always in the on state, it will cause the input voltage to directly charge the output battery end through the freewheeling tube. This process is uncontrollable. In this embodiment, the protection switching module is provided, and the input end of the protection switching module 130 is connected with the power supply switch module 110, and the output end is connected with the fuse F1. When a stuck failure of the power supply switch module is detected, the protection switching module 130 acts to control the rapid discharge of the energy storage module 120, generates a large current, that is, a fuse current, and blows the fuse, thereby playing a protection role. It should be noted that the stuck detection of the power supply switch module belongs to the prior art, because it is irrelevant to the gist of the present application, and will not be described here. As an example but not limitation, the protection switching module 130 can use a MOSFET as a switching device, and the discharge control of the energy storage module 120 is realized by controlling the conduction and disconnection of the MOSFET.

[0031] In this embodiment, when the power supply switch module 110 is working normally, the input power supply 20 supplies power to the load 30 through the fuse F1 and the power supply switch module 110, and at the same time the energy storage module 120 is in a charging state. When the power supply switch module 110 has a sticking failure, the protection switching module 130 detects the failure signal and responds quickly to control the energy storage module 120 to discharge through the protection switching module 130 and the fuse F1 to form a loop. Since the electrical energy stored in the energy storage module 120 is released in a short time, a large instantaneous current is generated, causing the fuse F1 to melt, thereby cutting off the connection between the input power supply 20 and the load 30, avoiding the risk of continuous charging due to the sticking failure of the power supply switch module 110.

[0032] In this embodiment, by setting the protection switching module 130 and the energy storage module 120, the fuse F1 is melted by using the rapid discharge capability of the energy storage module 120, thereby achieving effective protection against the sticking failure of the power supply switch module 110. Compared with the traditional scheme of adding a protection switch at the output end, the circuit structure is simple, the cost is low, and the response speed is fast, and the reliability is high.

[0033] In some other embodiments of the present application, another protection circuit is provided, and a structural schematic diagram thereof is shown in Figure 2 According to the protection circuit provided in this embodiment, the protection circuit includes a power supply switch module 110, a fuse F1, an energy storage module 120, a protection switching module 130, and a pre-charging module 140. The power supply switch module 110 is connected with the input power supply 20 through the fuse F1, and the power supply switch module 110 is also connected with the load 30. The energy storage module 120 is connected with the protection switching module 130 and the power supply switch module 110, and the protection switching module 130 is also connected with the fuse F1. The pre-charging module 140 is connected with the energy storage module 120 and the input power supply 20. The protection switching module 130 is used to act when the power supply switch module 110 has a sticking failure, so that the energy storage module 120 generates a melting current by discharging, and then the fuse F1 is melted.

[0034] In this embodiment, the power supply switch module 110 serves as the main control unit of the entire protection circuit, and is responsible for controlling the input power supply 20 to supply power to the load 30. The power supply switch module 110 includes a relay and a corresponding driving unit, and the contacts of the relay are connected between the input power supply 20 and the load 30, and the power supply control of the load 30 is realized by controlling the conduction and disconnection of the relay.

[0035] The fuse F1 is connected in series between the input power supply 20 and the power supply switch module 110, and when an abnormally large current appears in the circuit, the fuse F1 is melted to cut off the circuit. As an example but not limitation, the fuse F1 can be selected as a fast-melting fuse, and the rated current can be selected according to the actual application scenario.

[0036] The energy storage module 120 includes a capacitor bank for storing electrical energy. The energy storage module 120 is connected in parallel with the power supply switch module 110 and stores energy during normal operation. As an example but not limitation, the energy storage module 120 can employ a large electrolytic capacitor, and the capacitance can be selected according to the actual required discharge energy.

[0037] The protection switching module 130 includes a switching device for controlling the energy storage module 120 to discharge quickly when a failure of the power supply switch module 110 is detected. The input of the protection switching module 130 is connected with the power supply switch module 110, and the output is connected with the fuse F1. As an example but not limitation, the protection switching module 130 can employ a MOSFET as the switching device, and the discharge control of the energy storage module 120 is realized by controlling the conduction and blocking of the MOSFET.

[0038] The pre-charging module 140 is used for pre-charging the energy storage module 120. The pre-charging module 140 includes a pre-charging switching device and a driving circuit thereof, and the pre-charging switching device is connected with the energy storage module 120 in series with a current-limiting resistor. As an example but not limitation, the pre-charging switching device can employ a relay or a MOSFET, and the resistance value of the current-limiting resistor can be selected according to the pre-charging time requirement.

[0039] In this embodiment, when the device is started, the energy storage module 120 is first pre-charged by the pre-charging module 140, so as to avoid that the large-capacity capacitor in the energy storage module 120 causes an impact on the circuit when instantaneously charged. After the pre-charging is completed, the input power supply 20 supplies power to the load 30 through the fuse F1 and the power supply switch module 110, and the energy storage module 120 remains in a charged state. When the power supply switch module 110 occurs a sticking failure, the protection switching module 130 detects the failure signal and responds quickly, and controls the energy storage module 120 to discharge through the protection switching module 130 and the fuse F1 to form a loop. Since the electrical energy stored in the energy storage module 120 is released in a short time, a large instantaneous current is generated, which causes the fuse F1 to be fused, thereby cutting off the connection between the input power supply 20 and the load 30.

[0040] In this embodiment, by setting the pre-charging module 140, the soft start control of the energy storage module 120 is realized, and the inrush current generated when the large-capacity energy storage element is charged is avoided, and the reliability of the circuit is improved. At the same time, the pre-charging module 140 cooperates with the protection switching module 130 to quickly respond when the power supply switch module 110 occurs a sticking failure, and timely cuts off the failure circuit to protect the rear-end load.

[0041] In some embodiments of the present application, the circuit schematic diagram of the protection circuit is as shown in Figure 3As shown, the protection circuit provided by the embodiment mainly comprises five functional modules: a power supply switch module 110, a fuse F1, an energy storage module 120, a protection switching module 130, and a pre-charge module 140. The modules are connected by a reasonable circuit connection mode to realize protection of the power supply switch module 110 in a fault state.

[0042] In the embodiment, the power supply switch module 110 comprises an input relay RLY2 and a second driving unit. The input end of the input relay RLY2 is connected with the input power supply 20 through the fuse F1, the output end of the input relay RLY2 is connected with the load 30, and the control end of the input relay RLY2 is connected with the second driving unit. The circuit principle diagram of the second driving unit is as shown in Figure 5 As shown, the second driving unit mainly comprises a transistor Q1, diodes DS1 and DS2, a capacitor C1, and resistors R1 to R5, and is used to control the on-off of the relay RLY2.

[0043] The protection switching module 130 comprises a switch tube Q4 and a switch tube Q5. The source of the switch tube Q4 is connected with the second end of the fuse F1, and the drain of the switch tube Q4 is connected with the first end of the energy storage module 120. The source of the switch tube Q5 is connected with the second end of the energy storage module 120, and the drain of the switch tube Q5 is connected with the output end of the power supply switch module 110. The gates of the switch tube Q4 and the switch tube Q5 are connected with the controller, and are used to receive a control signal.

[0044] The energy storage module 120 comprises a capacitor CE1 and a capacitor CE2 connected in parallel. The positive poles of the capacitor CE1 and the capacitor CE2 are connected with the output end of the power supply switch module 110 and the first end of the protection switching module 130, and the negative poles of the capacitor CE1 and the capacitor CE2 are connected with the second end of the protection switching module 130 and grounded.

[0045] The pre-charge module 140 comprises an input relay RLY1, a pre-charge resistor RT1, a diode D1, a switch tube Q2, and a first driving unit. The input end of the input relay RLY1 is connected with the input end of the input relay RLY2, and the output end of the input relay RLY1 is connected with the source of the switch tube Q2 and the output end of the input relay RLY2 through the pre-charge resistor RT1. The drain of the switch tube Q2 is connected with the energy storage module 120, and the gate of the switch tube Q2 is connected with the controller. The circuit principle diagram of the first driving unit is as shown in Figure 4 As shown, the first driving unit comprises a transistor Q6 and resistors R6 and R7, and is used to control the on-off of the relay RLY1.

[0046] In this embodiment, the working process after the system is powered on can be divided into the following stages: pre-charge stage: first, the controller sends a control signal to the first drive unit to make the input relay RLY1 close, while the control switch tube Q2 is turned off. The input power supply 20 pre-charges the capacitor CE1 and the capacitor CE2 in the energy storage module 120 through the fuse F1, the input relay RLY1 and the pre-charge resistor RT1.

[0047] Normal working stage: after the pre-charge is completed, the controller controls the input relay RLY2 to close, at this time the input power supply 20 supplies power to the load 30 through the fuse F1 and the input relay RLY2. The energy storage module 120 remains in the charging state until the switch tube Q2 is closed after the charging is completed, at this time the switch tube Q4 and the switch tube Q5 are both in the off state.

[0048] Fault protection stage: when the input relay RLY2 has a sticking fault, the controller detects the fault signal and immediately controls the switch tube Q2 to be turned off, while the switch tube Q4 and the switch tube Q5 are turned on. The electrical energy stored in the capacitor CE1 and the capacitor CE2 in the energy storage module 120 is discharged quickly through the loop composed of the switch tube Q4, the fuse F1 and the switch tube Q5, generating a large enough current to make the fuse F1 melt and cut off the fault circuit.

[0049] In this embodiment, the controller judges whether a fault occurs by monitoring the working state of the power supply switch module 110. As an example but not limitation, the fault detection can be realized by detecting the contact position of the input relay RLY2, the current size or the voltage between the power supply switch module 110, etc. When a fault is detected, the controller needs to complete the switching action of turning off the switch tube Q2 and turning on the switch tube Q4 and the switch tube Q5 in a very short time to ensure the timeliness of the protection action.

[0050] Different from the prior art, the present application avoids the impact current when the energy storage module 120 starts through the setting of the pre-charge module 140. The timely protection of the relay sticking fault is realized through the quick action of the protection switching module 130 and the instantaneous large current discharge of the energy storage module 120. The whole protection circuit has simple structure, low cost and high reliability.

[0051] In some other embodiments of the present application, the circuit schematic of the protection circuit is as shown in Figure 6 The present embodiment provides a protection circuit scheme which simplifies the pre-charge circuit structure. The scheme includes the power supply switch module 110, the fuse F1, the energy storage module 120, the protection switching module 130 and the pre-charge module 140. The combination of the pre-charge resistor RT1 and the switch tube Q2 replaces the traditional pre-charge relay structure, which reduces the system cost while ensuring the pre-charge function.

[0052] In this embodiment, the power supply switch module 110 is composed of an input relay RLY2 and its second driving unit. The input terminal of the input relay RLY2 is connected with the input power supply 20 through the fuse F1, and the output terminal is connected with the load 30. The circuit principle diagram of the second driving unit is shown in Figure 5 Fig. 2, which contains the transistor Q1, diodes DS1 and DS2, capacitor C1 and related bias resistors, for controlling the reliable on-off of the relay. The driving circuit uses +12VP as the main power supply and +7VB as the auxiliary power supply, and through reasonable circuit design, the driving current of the relay coil is ensured to be stable.

[0053] The energy storage module 120 is composed of two large-capacity electrolytic capacitors CE1 and CE2 in parallel. The positive poles of the two capacitors are commonly connected to the output terminal of the input relay RLY2, and the negative poles are grounded. Through the parallel structure, the energy storage capacity is increased, ensuring that sufficient discharge current can be provided during protection action.

[0054] The protection switching module 130 contains two power MOSFETs: switch tube Q4 and switch tube Q5. The source of the switch tube Q4 is connected to the output terminal of the fuse F1, and the drain of the switch tube Q4 is connected to the positive pole of the energy storage module 120; the source of the switch tube Q5 is grounded, and the drain of the switch tube Q5 is connected to the negative pole of the energy storage module 120. The gates of the switch tube Q4 and the switch tube Q5 are driven by the controller, for controlling the discharge path of the energy storage capacitor.

[0055] The pre-charge module 140 adopts a simplified structure design, mainly composed of a pre-charge resistor RT1 and a switch tube Q2. One end of the pre-charge resistor RT1 is connected with the output terminal of the input relay RLY2 and the source of the switch tube Q2, and the other end is connected with the drain of the switch tube Q2 and the energy storage module 120. The gate of the switch tube Q2 is driven by the controller, for controlling the start and end of the pre-charge process.

[0056] In this embodiment, the working process of the circuit can be divided into three stages: pre-charge stage: at the initial power-on, the controller first makes the switch tube Q2 off, and the input voltage charges the energy storage module 120 through the fuse F1, the input relay RLY2 and the pre-charge resistor RT1. The pre-charge resistor RT1 limits the charging current, avoiding the inrush current at the start.

[0057] Normal operation stage: when the charging of the energy storage module 120 is completed, the controller controls the switch tube Q2 to close, and the input relay RLY2 remains closed to maintain the normal power supply path. At this time, the switch tube Q2 is turned on, and the switch tube Q4 and the switch tube Q5 are in the off state.

[0058] When the controller detects that the input relay RLY2 has a sticking fault, it immediately turns off the switch tube Q2 and turns on the switch tubes Q4 and Q5. The capacitor in the energy storage module 120 is discharged quickly through the low-impedance loop formed by the switch tube Q4, the fuse F1 and the switch tube Q5, and the large current generated causes the fuse F1 to melt, cutting off the faulty circuit.

[0059] In this embodiment, a combination of the pre-charge resistor RT1 and the switch tube Q2 is used to replace the traditional pre-charge relay, simplifying the circuit structure and reducing the circuit cost while ensuring reliable implementation of the pre-charge function.

[0060] This embodiment provides a protection scheme for a BUCK circuit. The circuit schematic diagram of the protection circuit is shown in Figure 7 The BUCK circuit further includes the switch tube Q3, the inductor LD1 and the capacitor CE3.

[0061] In this embodiment, the power supply switching module 110 includes the switch tube Q1. The drain of the switch tube Q1 is connected to the input power supply BAT_IN, and the source of the switch tube Q1 is connected to the output end OUT through the switch tube Q3 and the fuse F1. The gate of the switch tube Q1 and the gate of the switch tube Q3 are commonly connected to the controller, ensuring synchronous conduction and turn-off.

[0062] The energy storage module 120 adopts a parallel structure of two large-capacity electrolytic capacitors CE1 and CE2. The positive poles of the capacitors CE1 and CE2 are connected to the protection switching module 130, and the negative poles of the capacitors CE1 and CE2 are grounded. The parallel structure of the capacitors CE1 and CE2 not only increases the energy storage capacity, but also improves the response speed of the discharge loop by reducing the equivalent series inductance.

[0063] The protection switching module 130 includes the switch tubes Q4 and Q5. The source of the switch tube Q4 is connected to the source of the switch tube Q3, and the drain of the switch tube Q4 is connected to the positive pole of the energy storage module 120. The source of the switch tube Q5 is connected to the negative pole of the energy storage module 120, and the drain of the switch tube Q5 is connected to the source of the switch tube Q3. The gates of the switch tubes Q4 and Q5 are driven by the controller, which is used to control the discharge path of the energy storage capacitor.

[0064] The pre-charge module 140 includes the pre-charge resistor RT1 and the switch tube Q2. One end of the pre-charge resistor RT1 is connected to the source of the switch tube Q2 and the drain of the switch tube Q1, and the other end of the pre-charge resistor RT1 is connected to the drain of the switch tube Q2 and the energy storage module 120. The gate of the switch tube Q2 is connected to the controller, which is responsible for controlling the pre-charge process. The inductor LD1 and the capacitor CE3 constitute an output filter circuit, which is used to reduce the output ripple.

[0065] In this embodiment, the working process of the circuit is divided into the following stages: pre-charging stage: when the system starts, the controller first turns off the switch tube Q2, and the input voltage pre-charges the energy storage module 120 through the pre-charging resistor RT1. The pre-charging resistor RT1 limits the charging current to prevent excessive inrush current at the start.

[0066] Normal operation stage: after pre-charging is completed, the switch tube Q1 and the switch tube Q3 are synchronously switched under the control of the PWM signal to realize the step-down conversion function. The energy storage module 120 remains in the charging state, and after charging is completed, the switch tube Q2 is closed, and the switch tube Q4 and the switch tube Q5 are in the off state. The output voltage is filtered through the inductor LD1 and the capacitor CE3 and supplied to the load.

[0067] Fault protection stage: when a short circuit fault of the output MOS tube is detected, the controller immediately turns off the switch tube Q2, and controls the switch tube Q4 and the switch tube Q5 to be turned on. The capacitor of the energy storage module 120 is quickly discharged through the low-impedance loop composed of the switch tube Q4, the fuse F1 and the switch tube Q5, and the large current generated causes the fuse F1 to be blown, cutting off the fault circuit and preventing the energy from being backfed to the output end.

[0068] Through the innovative circuit topology design and the cooperative control of the switch tube Q4 and the switch tube Q5, the MOS tube fault in the BUCK circuit is quickly protected.

[0069] Based on the protection circuit provided in any of the above embodiments, the application further provides an energy storage power supply, which comprises the protection circuit provided in any of the above embodiments.

[0070] It should be noted that the specification and drawings of the utility model provide a preferred embodiment of the utility model, but the utility model can be realized in many different forms, and is not limited to the embodiments described in the specification, and these embodiments are not as additional limitations on the content of the utility model, and the purpose of providing these embodiments is to make the understanding of the disclosure of the utility model more thorough and comprehensive. Furthermore, the above technical features continue to combine, form various embodiments not listed above, and are considered as the range disclosed in the specification of the utility model; further, for those skilled in the art, the above description can be improved or changed, and all these improvements and changes should belong to the protection scope of the claims of the utility model.

Claims

1. A protection circuit, characterized by, The application relates to a power supply switching module, a fuse, an energy storage module and a protection switching module. The power supply switching module is connected with an input power supply through the fuse, and the power supply switching module is also connected with a load; the energy storage module is connected with the protection switching module and the power supply switching module; and the protection switching module is also connected with the fuse. The protection switching module is used for acting when the power supply switching module appears bonding failure, so that the energy storage module generates a fuse blowing current through discharging, and the fuse is blown. The protection switching module is used for acting when the power supply switching module appears bonding failure, so that the energy storage module generates the fuse blowing current through discharging of the protection switching module, the fuse and the power supply switching module.

2. The circuit of claim 1, wherein, The protection switching module comprises a switch tube Q4 and a switch tube Q5.

3. The circuit of claim 1, wherein, The first end of the fuse is connected with the input end of the power supply switching module; the source of the switch tube Q4 is connected with the second end of the fuse; the drain of the switch tube Q4 is connected with the first end of the energy storage module; the source of the switch tube Q5 is connected with the second end of the energy storage module; the drain of the switch tube Q5 is connected with the output end of the power supply switching module; and the gate of the switch tube Q4 is connected with the gate of the switch tube Q5 and a controller. The energy storage module comprises a capacitor CE1 and a capacitor CE2.

4. The circuit of claim 1, wherein, The positive pole of the capacitor CE1 is connected with the positive pole of the capacitor CE2, the output end of the power supply switching module and the first end of the protection switching module; and the second end of the capacitor CE1, the second end of the capacitor CE2 and the second end of the protection switching module are grounded. The power supply switching module comprises an input relay RLY2 and a second driving unit.

5. The circuit of claim 1, wherein, The input end of the input relay RLY2 is connected with the input power supply through the fuse; the output end of the input relay RLY2 is connected with the load; and the control end of the input relay RLY2 is connected with the second driving unit. The pre-charging module is also connected with the energy storage module and the input power supply.

6. The circuit of claim 5, wherein, The pre-charging module is used for pre-charging the energy storage module based on the input power supply. The pre-charging module comprises an input relay RLY1, a pre-charging resistor RT1, a diode D1, a switch tube Q2 and a first driving unit.

7. The circuit of claim 6, wherein, The input end of the input relay RLY1 is connected with the input end of the input relay RLY2; the output end of the input relay RLY1 is connected with the first end of the pre-charging resistor RT1; the second end of the pre-charging resistor RT1 is connected with the source of the switch tube Q2 and the output end of the input relay RLY2; the drain of the switch tube Q2 is connected with the energy storage module; the gate of the switch tube Q2 is connected with a controller; the first control end of the input relay RLY1 is connected with the first driving unit and the anode of the diode D1; the cathode of the diode D1 is connected with the second control end of the input relay RLY1 and a driving power supply. The pre-charging module comprises a pre-charging resistor RT1 and a switch tube Q2.

8. The circuit of claim 6, wherein, ​ The first end of the pre-charge resistor RT1 is connected with the source of the switch tube Q2 and the output end of the input relay RLY2, the second end of the pre-charge resistor RT1 is connected with the drain of the switch tube Q2 and the energy storage module, and the gate of the switch tube Q2 is connected with the controller.

9. The circuit of claim 6, wherein, The protection circuit further comprises a switch tube Q3, an inductor LD1 and a capacitor CE3, and the power supply switching module comprises a switch tube Q1, The source of the switch tube Q3 is connected with the load through the fuse, the drain of the switch tube Q3 is connected with the first end of the inductor LD1 and the positive pole of the capacitor CE3, the second end of the inductor LD1 is connected with the source of the switch tube Q1, the drain of the switch tube Q1 is connected with the input power supply, the gate of the switch tube Q1 is connected with the gate of the switch tube Q3 and the controller; the pre-charge module comprises a pre-charge resistor RT1 and a switch tube Q2, The first end of the pre-charge resistor RT1 is connected with the source of the switch tube Q2 and the drain of the switch tube Q1, the second end of the pre-charge resistor RT1 is connected with the drain of the switch tube Q2 and the energy storage module, and the gate of the switch tube Q2 is connected with the controller.

10. An energy storage power supply, characterized by, Comprise: The protection circuit according to any one of claims 1-9.

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