A fault detection circuit and energy storage power supply

Abstract

The utility model relates to the technical field of energy storage power supply mainly provides fault detection circuit and energy storage power supply, and this fault detection circuit includes detection module, and the sampling module and drive module connected with detection module respectively, sampling module and drive module still all are connected with bridge circuit. Sampling module is used for gathering the current signal of bridge circuit, and first voltage signal and / or second voltage signal are exported based on the state output of current signal. When bridge circuit does not appear the fault, detection module will receive first voltage signal and second voltage signal alternately, thereby making drive module control bridge circuit normal work. When bridge circuit appears the fault, sampling module only exports first / second voltage signal, detection module will make drive module control bridge circuit stop working at this moment. Based on this, namely can close the drive of bridge circuit when bridge circuit appears the fault, to avoid appearing power tube breakdown and so on phenomenon in bridge circuit, thereby improved the reliability of energy storage power supply.

Description

[Technical Field]

[0002] This utility model relates to the technical field of energy storage power supplies, and in particular to a fault detection circuit and an energy storage power supply. [Background Technology]

[0004] In the development of modern power electronics technology, LLC resonant converters have been widely used in server power supplies, new energy vehicle charging, and industrial automation due to their significant advantages such as high-efficiency soft-switching characteristics, wide input voltage range adaptability, and low electromagnetic interference (EMI). The LLC 4-bridge driver circuit, as the core topology of the LLC resonant converter, achieves DC-to-high-frequency AC conversion through the complementary on / off switching of four metal-oxide-semiconductor field-effect transistors (MOS transistors), and completes efficient power transmission and conversion with the help of a resonant network.

[0005] However, in existing technologies, when one of the four MOSFETs malfunctions, the circuit does not immediately stop operating. Under low power demands, this malfunction is difficult to detect promptly due to the light overall system load, and the circuit can still appear to operate normally. However, as the load power increases, the drawbacks of malfunctioning MOSFETs are amplified dramatically. When one MOSFET malfunctions, the circuit cannot maintain the ideal state of four-MOSFET coordinated operation; in reality, only two MOSFETs can participate in power transfer normally. This asymmetrical operating mode disrupts the original current balance of the circuit, causing the malfunctioning MOSFET and its associated devices to experience excessive voltage and current stress, leading to problems such as a sudden increase in local current density and increased heat dissipation. Over long periods of operation, excessive thermal and electrical stress will accelerate device aging, ultimately causing serious damage such as MOSFET breakdown and circuit board burnout. This not only reduces the lifespan of the equipment but may also cause safety accidents such as fires, significantly limiting the reliability and stability of LLC 4-bridge driver circuits in high-power applications. [Utility Model Content]

[0007] This utility model provides a fault detection circuit and an energy storage power supply, aiming to solve the technical problem that the energy storage power supply continues to work even when the MOSFET is faulty, resulting in a decrease in the reliability of the energy storage power supply.

[0008] To solve the above-mentioned technical problems, one technical solution adopted by this utility model is to provide a fault detection circuit, which includes a sampling module, a detection module and a driving module.

[0009] The sampling module is connected to the detection module, the detection module is connected to the driving module, and both the sampling module and the driving module are also connected to a bridge circuit.

[0010] The sampling module is used to acquire the current signal of the bridge circuit and output a corresponding voltage signal to the detection module based on the state of the current signal, wherein the voltage signal includes a first voltage signal and a second voltage signal;

[0011] The detection module is used to receive and detect the voltage signal, and when the first voltage signal and the second voltage signal are received alternately, output a control signal to the drive module, so that the drive module controls the bridge circuit to operate normally according to the control signal; and

[0012] When neither the first voltage signal nor the second voltage signal is received, the output control signal to the drive module is stopped, so that the drive module controls the bridge circuit to stop working.

[0013] Optionally, the control signal includes a first control signal and a second control signal, and the drive module is used to control the bridge circuit to operate normally when it receives the first control signal and the second control signal; and

[0014] If neither the first control signal nor the second control signal is received, the bridge circuit is controlled to stop working.

[0015] Optionally, the detection module includes a first detection unit and a second detection unit;

[0016] Both the first detection unit and the second detection unit are connected to the sampling module and the driving module, respectively;

[0017] The first detection unit is used to output a first control signal for a first preset time according to the first voltage signal when it receives the first voltage signal, so as to extend the time when the drive module receives the first control signal;

[0018] The second detection unit is used to output a second control signal for a second preset time according to the second voltage signal when it receives the second voltage signal, so as to extend the time when the drive module receives the second control signal.

[0019] Optionally, the first detection unit includes a first filtering subunit and a first output subunit;

[0020] The first output subunit is connected to the sampling module and the driving module respectively, and the first filtering subunit is connected to the first output subunit;

[0021] The first filtering subunit is used to process the first voltage signal after receiving the first voltage signal, and output the processed first voltage signal to the first output subunit, so that the first output subunit continuously outputs a first control signal for a first preset time based on the processed first voltage signal.

[0022] Optionally, the first output subunit includes a voltage follower U2 and a resistor R13;

[0023] The non-inverting input of the voltage follower U2 is connected to the first filter subunit, the output of the voltage follower U2 is connected to the resistor R13, the resistor R13 is connected to the inverting input of the voltage follower U2, and the resistor R13 is also connected to the drive module.

[0024] Optionally, the second detection unit includes a second filtering subunit and a second output subunit;

[0025] The second output subunit is connected to both the sampling module and the driving module, and the second filtering subunit is connected to the second output subunit.

[0026] The second filtering subunit is used to process the second voltage signal after receiving the second voltage signal, and output the processed second voltage signal to the second output subunit, so that the second output subunit continuously outputs a second control signal for a second preset time based on the processed second voltage signal.

[0027] Optionally, the second output sub-unit includes resistor R18, resistor R19, and operational amplifier U3;

[0028] The non-inverting input of the operational amplifier U3 is connected to the second filter subunit. The non-inverting input of the operational amplifier U3 is also connected to the output of the operational amplifier U3 through the resistor R18. The inverting input of the operational amplifier U3 is grounded. The output of the operational amplifier U3 is connected to the drive module.

[0029] Optionally, the driving module is an XOR gate U4;

[0030] The first input terminal of the XOR gate U4 is connected to the first detection unit, the second input terminal of the XOR gate U4 is connected to the second detection unit, and the output terminal of the XOR gate U4 is connected to the bridge circuit.

[0031] Optionally, the sampling module includes resistors R8, R9, R10, R20 and operational amplifier U1;

[0032] The resistor R8 is connected to the bridge circuit, the resistor R9 is connected in parallel with the resistor R8, the two input terminals of the operational amplifier U1 are connected to the two ends of the resistor R9, the non-inverting input terminal of the operational amplifier U1 is also connected to the ground terminal through the resistor R10, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1 through the resistor R20, and the output terminal of the operational amplifier U1 is also connected to the detection module.

[0033] To solve the above-mentioned technical problems, another technical solution adopted in this utility model embodiment is: to provide an energy storage power source, the energy storage power source comprising:

[0034] Bridge circuit;

[0035] Batteries; and

[0036] The fault detection circuit described above.

[0037] Unlike related technologies, this utility model provides a fault detection circuit and an energy storage power supply. The fault detection circuit includes a sampling module, a detection module, and a driving module. The sampling module is connected to the detection module, and the detection module is connected to the driving module. Both the sampling module and the driving module are also connected to a bridge circuit. The sampling module is used to collect the current signal of the bridge circuit and output a corresponding voltage signal to the detection module based on the state of the current signal. The voltage signal includes a first voltage signal and a second voltage signal. When the bridge circuit is not faulty, the detection module alternately receives the first voltage signal and the second voltage signal. At this time, the detection module outputs a control signal to the driving module, so that the driving module controls the bridge circuit to work normally according to the control signal. When the bridge circuit is faulty, the sampling module only outputs the first voltage signal or the second voltage signal. When the detection module does not detect the first voltage signal or the second voltage signal, it stops outputting the control signal to the driving module, thereby causing the driving module to control the bridge circuit to stop working. Based on this, the bridge circuit drive can be shut down when a fault occurs, thus avoiding phenomena such as MOSFET breakdown in the bridge circuit and improving the reliability of the energy storage power supply. [Attached Image Description]

[0039] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0040] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of the present utility model;

[0041] Figure 2 This is a circuit diagram of an energy storage power supply provided in an embodiment of the present utility model;

[0042] Figure 3 This is a structural block diagram of a fault detection circuit provided in an embodiment of the present invention;

[0043] Figure 4 This is a circuit diagram of a fault detection circuit provided in an embodiment of this utility model.

Detailed Implementation Methods

[0045] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0046] The technical features involved in the various embodiments of this application described below do not conflict with each other and can be combined with each other.

[0047] When an element is described as "connected" to another element, it can be directly connected to the other element, or there may be one or more intervening elements between them.

[0048] The terms "first," "second," etc., used in the specification and claims of this utility model are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, the first object can be one or more.

[0049] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0050] Please see Figure 1 , Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of the present utility model, such as... Figure 1As shown, this application scenario 1 includes an energy storage power supply 100 and a load 200. The energy storage power supply 100 is connected to the load 200. The energy storage power supply 100 is used to output a power supply voltage to the load 200 to supply power to the load 200.

[0051] Among them, such as Figure 1 As shown, the energy storage power supply 100 includes a battery 10, a bridge circuit 20, an LLC resonant circuit 30, and a high-voltage side rectifier circuit 40. The bridge circuit 20 is connected to both the battery 10 and the LLC resonant circuit 30. The LLC resonant circuit 30 is connected to the high-voltage side rectifier circuit 40, which is also connected to the load 200. During the process of the energy storage power supply 100 supplying power to the load 200, the power transistors in the bridge circuit 20 alternately conduct to output positive or negative current to the LLC resonant circuit 30, causing the LLC resonant circuit 30 to resonate based on the continuously changing current. This allows the high-voltage side rectifier circuit 40 to output a target voltage, thereby supplying power to the load 200.

[0052] It should be noted that when the power transistors in the bridge circuit 20 are alternately turned on, if one power transistor fails, it will cause the faulty power transistor and its associated devices to be subjected to excessive voltage and current stress, thereby damaging the devices in the circuit. Therefore, in order to improve the reliability of the energy storage power supply 100, this embodiment of the application also includes a fault detection circuit 50. The fault detection circuit 50 is connected to the bridge circuit 20. The fault detection circuit 50 is used to collect the current signal of the bridge circuit 20 when the energy storage power supply 100 is working, and determine whether all the power transistors in the bridge circuit 20 are working normally based on the state of the current signal (whether there is an alternating positive and negative current signal). When no positive or negative current signal is detected, it is determined that one of the power transistors in the bridge circuit 20 has failed. At this time, the fault detection circuit 50 will turn off the drive of the power transistor in the bridge circuit 20, so that the bridge circuit 20 stops working, thereby protecting the energy storage power supply 100.

[0053] In some embodiments, please refer to Figure 2 , Figure 2 This is a circuit diagram of an energy storage power supply provided in an embodiment of this utility model, such as... Figure 2As shown, the bridge circuit 20 is a full-bridge circuit, meaning it includes power transistors Q1, Q2, Q4, and Q5. Power transistors Q2 and Q4 are connected in series, and power transistors Q1 and Q5 are also connected in parallel. Power transistors Q2 and Q4 operate alternately, as do power transistors Q1 and Q5, and their conduction states are the same. In another embodiment, the bridge circuit 20 can be a half-bridge circuit, meaning it includes power transistors Q2 and Q4, which are connected in series and conduct alternately, thereby outputting alternating positive and negative current signals.

[0054] In some embodiments, the energy storage power supply 100 further includes a controller (not shown), such as Figure 2 As shown, the bridge circuit 20 also includes a current transformer CT1, which is connected to the fault detection circuit 50. The controller is connected to the bridge circuit 20. The current transformer CT1 is used to collect the current signal of the bridge circuit 20 in real time and input the current signal to the fault detection circuit 50 so that the fault detection circuit 50 can determine whether the power transistor in the bridge circuit 20 has failed based on the current signal. If the power transistor in the bridge circuit 20 fails, the fault detection circuit 50 will stop outputting the drive signal to the controller. When the controller does not receive the drive signal, it will turn off the drive of the power transistor in the bridge circuit 20, thereby causing the power transistor in the bridge circuit 20 to stop working and thus protecting the energy storage power supply 100.

[0055] In some embodiments, please refer to Figure 3 , Figure 3 This is a structural block diagram of a fault detection circuit provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the fault detection circuit 50 includes a sampling module 51, a detection module 52, and a driving module 53;

[0056] The sampling module 51 is connected to the detection module 52, the detection module 52 is connected to the driving module 53, and both the sampling module 51 and the driving module 53 are also connected to the bridge circuit 20.

[0057] The sampling module 51 is used to collect the current signal of the bridge circuit 20 and output a corresponding voltage signal to the detection module 52 based on the state of the current signal. The voltage signal includes a first voltage signal and a second voltage signal.

[0058] The detection module 52 is used to receive and detect the voltage signal, and when the first voltage signal and the second voltage signal are received alternately, output a control signal to the drive module 53, so that the drive module 53 controls the bridge circuit 20 to operate normally according to the control signal; and

[0059] When neither the first voltage signal nor the second voltage signal is received, the output control signal to the drive module 53 is stopped, so that the drive module 53 controls the bridge circuit 20 to stop working.

[0060] It is understood that when the bridge circuit 20 is functioning normally, it will alternately output a first current signal and a second current signal. When the sampling module 52 acquires the current signal from the bridge circuit 20, it will also alternately acquire the first current signal and the second current signal, converting them into a first voltage signal and a second voltage signal respectively. Finally, the converted voltage signal is input to the detection module 52. When the detection module 52 alternately receives the first voltage signal and the second voltage signal, it determines that the power transistors in the bridge circuit 20 are functioning normally. At this time, the detection module 52 will output a control signal to the drive module 53 based on the first voltage signal and the second voltage signal, causing the drive module 53 to output a drive signal to the bridge circuit 20, thereby enabling the bridge circuit 20 to function normally.

[0061] When a power transistor in the bridge circuit 20 fails, the bridge circuit 20 can only output a first current signal or a second current signal. At this time, the sampling module 51 can only output a first voltage signal or a second voltage signal to the detection module 52 based on the current signal. When the detection module 52 does not receive the first voltage signal or the second voltage signal, it confirms that a power transistor in the bridge circuit 20 has failed. The detection module 52 then stops outputting control signals, causing the drive module 53 to stop outputting drive signals, thereby stopping the bridge circuit 20 from operating. Based on this, when the bridge circuit 20 fails, its drive can be shut down, thus protecting the energy storage power supply 100.

[0062] In another embodiment, the control signal includes a first control signal and a second control signal, and the drive module 53 is used to control the bridge circuit 20 to operate normally when it receives the first control signal and the second control signal; and

[0063] When neither the first control signal nor the second control signal is received, the bridge circuit 20 is controlled to stop working.

[0064] When the sampling module 51 outputs a corresponding voltage signal based on the first current signal and the second current signal, the detection module 52 detects the voltage signal. If the voltage signal is the first voltage signal, the detection module 52 outputs a first control signal to the drive module 53 based on the first voltage signal; and if the voltage signal is the second voltage signal, the detection module 52 outputs a second control signal to the drive module 53 based on the second voltage signal. When the drive module 53 receives the first control signal and the second control signal, it outputs a drive signal to the bridge circuit 20 to drive the bridge circuit 20 to start working.

[0065] When the sampling module 51 fails to acquire the first current signal and / or the second current signal, the detection module 53 will only receive the first voltage signal or the second voltage signal. In this case, the detection module 53 will not output the first control signal or the second control signal. Conversely, when the driving module 53 fails to receive the first control signal or the second control signal, it will stop outputting the driving signal, thereby causing the bridge circuit 20 to stop working and preventing damage to the components in the circuit.

[0066] In another embodiment, such as Figure 3 As shown, the detection module 52 includes a first detection unit 521 and a second detection unit 522;

[0067] The first detection unit 521 and the second detection unit 522 are respectively connected to the sampling module 51 and the driving module 53;

[0068] The first detection unit 521 is used to output a first control signal for a first preset time according to the first voltage signal when it receives the first voltage signal, so as to extend the time when the drive module 53 receives the first control signal;

[0069] The second detection unit 522 is used to output a second control signal for a second preset time according to the second voltage signal when it receives the second voltage signal, so as to extend the time when the drive module 53 receives the second control signal.

[0070] Specifically, when the sampling module 51 alternately receives the first current signal and the second current signal, it alternately outputs the first voltage signal and the second voltage signal to the detection module 52. When the sampling module 51 outputs the first voltage signal, the first detection unit 521 receives the first voltage signal and outputs a first control signal for a first preset time to the drive module 53 based on the first voltage signal. When the sampling module 51 outputs the second voltage signal, the second detection unit 522 receives the second voltage signal and outputs a second control signal for a second preset time based on the second voltage signal. Based on this, when the power transistor in the bridge circuit 20 is normal, the drive module can simultaneously receive the first control signal and the second control signal, thereby maintaining the operation of the bridge circuit 20.

[0071] If the sampling module 51 stops outputting the first voltage signal or the second voltage signal, the first detection unit 521 or the second detection unit 522 will not receive the corresponding voltage signal, thus stopping the output of the corresponding control signal to the drive module 53. When the drive module 53 does not simultaneously receive the first control signal and the second control signal, the drive module 53 will control the bridge circuit 20 to stop working. For example, if the power transistor Q4 in the bridge circuit 20 fails, the sampling module 51 will not collect the current signal of the negative half-cycle, so the sampling module 51 will only output the first voltage signal, the first detection unit 521 will output the first control signal, and the second detection unit 522 will not output a signal, thereby causing the drive module 53 to stop outputting the drive signal, and the bridge circuit 20 to stop working. It should be noted that the first preset time and the second preset time are set according to the duty cycle of the bridge circuit 20. Based on the duty cycle of the bridge circuit 20, the output time of the first current signal and the second current signal can be determined. By delaying the first voltage signal and the second voltage signal by a preset time, the driving module 53 can receive the second voltage signal at the same time as receiving the first voltage signal. Thus, when the power transistor in the bridge circuit 20 is not faulty, the driving module 53 can continuously control the bridge circuit 20 to work normally.

[0072] Furthermore, in some embodiments, such as Figure 3 As shown, the first detection unit 521 includes a first filtering subunit 5211 and a first output subunit 5212;

[0073] The first output subunit 5212 is connected to the sampling module 51 and the driving module 53 respectively, and the first filtering subunit 5211 is connected to the first output subunit 5212.

[0074] The first filtering subunit 5211 is used to process the first voltage signal after receiving the first voltage signal, and output the processed first voltage signal to the first output subunit 5212, so that the first output subunit 5212 continuously outputs a first control signal for a first preset time based on the processed first voltage signal.

[0075] Specifically, when the sampling module 51 outputs the first voltage signal, the first filtering subunit 5211 receives the first voltage signal, filters it, and inputs the filtered first voltage signal to the first output subunit 5212. This causes the first output subunit 5212 to output a first control signal for a first preset time based on the processed first voltage signal. Therefore, even when the sampling module 51 stops outputting the first voltage signal, the first detection unit 521 can still output the first control signal for a period of time, allowing the driving module 53 to simultaneously receive both the first voltage signal and the second voltage signal.

[0076] For further details, please refer to Figure 4 , Figure 4 This is a circuit diagram of a fault detection circuit provided in an embodiment of this utility model, as shown below. Figure 4 As shown, the first filter subunit 5211 includes a diode D2 and a capacitor C8; the first output subunit 5212 includes a voltage follower U2 and a resistor R13.

[0077] The anode of the diode D2 is connected to the sampling module 51, the cathode of the diode D2 is connected to the first end of the capacitor C8, the first end of the capacitor C8 is also connected to the first output sub-unit 5212, and the second end of the capacitor C8 is used for grounding.

[0078] The non-inverting input of the voltage follower U2 is connected to the first filter subunit, the output of the voltage follower U2 is connected to the resistor R13, the resistor R13 is connected to the inverting input of the voltage follower U2, and the resistor R13 is also connected to the drive module.

[0079] When the sampling module 51 alternately outputs a first voltage signal and a second voltage signal, the diode D2 receives the first voltage signal and inputs it to the capacitor C8. Upon receiving the first voltage signal, the capacitor C8 filters it and inputs the processed first voltage signal to the voltage follower U2. The voltage follower U2, upon receiving the processed first voltage signal, outputs a first control signal lasting for a first preset time. It should be noted that during the filtering process of the first voltage signal, the capacitor C8 charges based on the first voltage signal and begins discharging when it does not receive the first voltage signal, thereby causing the voltage follower U2 to output the first control signal lasting for the first preset time.

[0080] In another embodiment, such as Figure 3 As shown, the second detection unit 522 includes a second filtering subunit 5221 and a second output subunit 5222;

[0081] The second output subunit 5222 is connected to the sampling module 51 and the driving module 53 respectively, and the second filtering subunit 5221 is connected to the second output subunit 5222;

[0082] The second filtering subunit 5221 is used to process the second voltage signal after receiving it, and output the processed second voltage signal to the second output subunit 5222, so that the second output subunit 5222 continuously outputs a second control signal for a second preset time based on the processed second voltage signal. It should be noted that the working principle of the second detection unit 522 is similar to that of the first detection unit 521, and will not be described again here.

[0083] In yet another embodiment, such as Figure 4 As shown, the second filter subunit 5221 includes a diode D3 and a capacitor C10; the second output subunit 5222 includes a resistor R18, a resistor R19 and an operational amplifier U3;

[0084] The cathode of the diode D3 is connected to the sampling module 51, the anode of the diode D3 is connected to the first end of the capacitor C10, the first end of the capacitor C10 is also connected to the second output sub-unit 5222, and the second end of the capacitor C10 is used for grounding.

[0085] The non-inverting input of the operational amplifier U3 is connected to the second filter subunit 5221. The non-inverting input of the operational amplifier U3 is also connected to the output of the operational amplifier U3 through the resistor R18. The inverting input of the operational amplifier U3 is grounded. The output of the operational amplifier U3 is connected to the drive module 53.

[0086] When the sampling module 51 outputs a voltage signal, the diode D3 receives the second voltage signal and inputs it to the capacitor C10. The capacitor C10 then filters the second voltage signal and inputs the filtered signal to the operational amplifier U3. This causes the operational amplifier U3 to output a second control signal for a second preset time based on the second voltage signal. It should be noted that the operational amplifier U3 is an inverting amplifier. The characteristic of an inverting amplifier is that the input signal and output signal are out of phase; that is, when the input signal is the positive half-cycle signal, the output signal is the negative half-cycle signal.

[0087] In another embodiment, such as Figure 4 As shown, the driving module 53 is an XOR gate U4;

[0088] The first input terminal of the XOR gate U4 is connected to the first detection unit 521, the second input terminal of the XOR gate U4 is connected to the second detection unit 522, and the output terminal of the XOR gate U4 is connected to the bridge circuit 20.

[0089] It should be noted that in this embodiment, both the first control signal and the second control signal are high-level signals. Specifically, based on the current sampling of the bridge circuit 20, the first current signal is a current signal of the positive half-cycle, and the second current signal is a current signal of the negative half-cycle. After conversion by the sampling module 51, the first voltage signal is a positive voltage, and the second voltage signal is a negative voltage. At this time, when the positive voltage is input to the first detection unit 521, the first detection unit 521 will output a high-level signal based on the voltage follower U2. When the negative voltage is input to the second detection unit 522, since the operational amplifier U3 is an inverting amplifier, the second detection unit 522 will also output a high-level signal.

[0090] Therefore, based on the characteristics of the XOR gate, when the XOR gate U4 simultaneously receives the first control signal and the second control signal, the XOR gate U4 will output a drive signal to drive the bridge circuit 20 to work normally. However, if the XOR gate U4 does not simultaneously receive a high-level signal (neither the first nor the second control signal is received), the XOR gate U4 will not output a drive signal, thereby causing the bridge circuit 20 to stop working.

[0091] In other embodiments, such as Figure 4 As shown, the sampling module 51 includes resistors R8, R9, R10, R20 and operational amplifier U1;

[0092] The resistor R8 is connected to the bridge circuit 20, the resistor R9 is connected in parallel with the resistor R8, the two input terminals of the operational amplifier U1 are connected to the two ends of the resistor R9, the non-inverting input terminal of the operational amplifier U1 is also connected to the ground terminal through the resistor R10, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1 through the resistor R20, and the output terminal of the operational amplifier U1 is also connected to the detection module 52.

[0093] When the bridge circuit 20 is working, the current in the bridge circuit 20 is input to the current transformer CT1. When the current transformer CT1 receives the current signal, it inputs the current signal to the sampling module 51. At this time, corresponding voltage signals are generated across resistors R8 and R9, and these voltage signals are input to the operational amplifier U1 for proportional amplification. Finally, the amplified voltage signal is input to the detection module 52 so that the detection module 52 can receive and detect the voltage signal.

[0094] In some embodiments, please combine Figure 2 and Figure 4When power transistors Q1, Q2, Q4, and Q5 in the bridge circuit 20 operate alternately, positive and negative currents alternately flow through the current transformer CT1. At this time, the current transformer CT1 inputs the alternating positive and negative currents to the two ends of resistors R8 and R9, thereby generating corresponding positive and negative voltages. These positive and negative voltages are then input to the operational amplifier U1 for proportional amplification before being output. When the operational amplifier U1 outputs the amplified positive voltage (the first voltage signal), due to the characteristics of diodes D2 and D3, this positive voltage is input to capacitor C8, filtered by capacitor C8, and then input to the voltage follower U2. When the voltage follower U2 receives the filtered positive voltage, it outputs a high-level signal for a first preset time to the first input terminal of the XOR gate U4 based on the positive voltage. Simultaneously, when the operational amplifier U1 outputs an amplified negative voltage, this negative voltage is filtered by the capacitor C10 and input to the operational amplifier U4. Since the operational amplifier U4 is an inverting amplifier, it outputs a high-level signal for a second preset time to the XOR gate U4. When the XOR gate U4 receives both high-level signals simultaneously, it outputs a drive signal to the bridge circuit 20, thereby enabling the power transistors in the bridge circuit 20 to operate normally.

[0095] When a power transistor in the bridge circuit 20 fails, the current transformer CT1 does not detect a positive or negative current. At this time, the operational amplifier U1 will only output an amplified positive or negative voltage, causing the voltage follower U2 or operational amplifier U4 to not output a signal. Since the XOR gate U4 receives different signals, it will not output a drive signal. Consequently, the bridge circuit 20 will stop working due to the lack of a drive signal. Therefore, the bridge circuit 20 can stop working when a power transistor in the bridge circuit 20 fails, thereby improving the reliability of the energy storage system 100.

[0096] This utility model embodiment provides a fault detection circuit, which includes a sampling module, a detection module, and a driving module. The sampling module is connected to the detection module, and the detection module is connected to the driving module. Both the sampling module and the driving module are also connected to a bridge circuit. The sampling module is used to collect the current signal of the bridge circuit and output a corresponding voltage signal to the detection module based on the state of the current signal. The voltage signal includes a first voltage signal and a second voltage signal. When the bridge circuit is not faulty, the detection module will alternately receive the first voltage signal and the second voltage signal. At this time, the detection module will output a control signal to the driving module so that the driving module controls the bridge circuit to work normally according to the control signal. When the bridge circuit is faulty, the sampling module only outputs the first voltage signal or the second voltage signal. When the detection module does not detect the first voltage signal or the second voltage signal, it will stop outputting the control signal to the driving module, thereby causing the driving module to control the bridge circuit to stop working. Based on this, the bridge circuit drive can be shut down when a fault occurs, thus avoiding phenomena such as MOSFET breakdown in the bridge circuit and improving the reliability of the energy storage power supply.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; under the concept of this utility model, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this utility model as described above, which are not provided in detail for the sake of brevity; although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A fault detection circuit, characterized in that, The fault detection circuit includes a sampling module, a detection module, and a driving module; The sampling module is connected to the detection module, the detection module is connected to the driving module, and both the sampling module and the driving module are also connected to a bridge circuit. The sampling module is used to acquire the current signal of the bridge circuit and output a corresponding voltage signal to the detection module based on the state of the current signal, wherein the voltage signal includes a first voltage signal and a second voltage signal; The detection module is used to receive and detect the voltage signal, and when the first voltage signal and the second voltage signal are received alternately, output a control signal to the drive module, so that the drive module controls the bridge circuit to operate normally according to the control signal; and When neither the first voltage signal nor the second voltage signal is received, the output control signal to the drive module is stopped, so that the drive module controls the bridge circuit to stop working.

2. The fault detection circuit according to claim 1, characterized in that, The control signal includes a first control signal and a second control signal. The drive module is used to control the bridge circuit to work normally when it receives the first control signal and the second control signal. as well as If neither the first control signal nor the second control signal is received, the bridge circuit is controlled to stop working.

3. The fault detection circuit according to claim 2, characterized in that, The detection module includes a first detection unit and a second detection unit; Both the first detection unit and the second detection unit are connected to the sampling module and the driving module, respectively; The first detection unit is used to output a first control signal for a first preset time according to the first voltage signal when it receives the first voltage signal, so as to extend the time when the drive module receives the first control signal; The second detection unit is used to output a second control signal for a second preset time according to the second voltage signal when it receives the second voltage signal, so as to extend the time when the drive module receives the second control signal.

4. The fault detection circuit according to claim 3, characterized in that, The first detection unit includes a first filtering subunit and a first output subunit; The first output subunit is connected to the sampling module and the driving module respectively, and the first filtering subunit is connected to the first output subunit; The first filtering subunit is used to process the first voltage signal after receiving the first voltage signal, and output the processed first voltage signal to the first output subunit, so that the first output subunit continuously outputs a first control signal for a first preset time based on the processed first voltage signal.

5. The fault detection circuit according to claim 4, characterized in that, The first output subunit includes a voltage follower U2 and a resistor R13; The non-inverting input of the voltage follower U2 is connected to the first filter subunit, the output of the voltage follower U2 is connected to the resistor R13, the resistor R13 is connected to the inverting input of the voltage follower U2, and the resistor R13 is also connected to the drive module.

6. The fault detection circuit according to claim 3, characterized in that, The second detection unit includes a second filtering subunit and a second output subunit; The second output subunit is connected to both the sampling module and the driving module, and the second filtering subunit is connected to the second output subunit. The second filtering subunit is used to process the second voltage signal after receiving the second voltage signal, and output the processed second voltage signal to the second output subunit, so that the second output subunit continuously outputs a second control signal for a second preset time based on the processed second voltage signal.

7. The fault detection circuit according to claim 6, characterized in that, The second output subunit includes resistors R18 and R19 and operational amplifier U3; The non-inverting input of the operational amplifier U3 is connected to the second filter subunit. The non-inverting input of the operational amplifier U3 is also connected to the output of the operational amplifier U3 through the resistor R18. The inverting input of the operational amplifier U3 is grounded. The output of the operational amplifier U3 is connected to the drive module.

8. The fault detection circuit according to any one of claims 3-7, characterized in that, The driving module is an XOR gate U4; The first input terminal of the XOR gate U4 is connected to the first detection unit, the second input terminal of the XOR gate U4 is connected to the second detection unit, and the output terminal of the XOR gate U4 is connected to the bridge circuit.

9. The fault detection circuit according to any one of claims 1-7, characterized in that, The sampling module includes resistors R8, R9, R10, and R20, and operational amplifier U1; The resistor R8 is connected to the bridge circuit, the resistor R9 is connected in parallel with the resistor R8, the two input terminals of the operational amplifier U1 are connected to the two ends of the resistor R9, the non-inverting input terminal of the operational amplifier U1 is also connected to the ground terminal through the resistor R10, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1 through the resistor R20, and the output terminal of the operational amplifier U1 is also connected to the detection module.

10. An energy storage power source, characterized in that, The energy storage power source includes: Bridge circuit; Batteries; and The fault detection circuit as described in any one of claims 1-9.

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