Discharge circuit and energy storage power supply

Abstract

The utility model relates to the technical field of energy storage power supply mainly provides a discharge circuit and energy storage power supply, and discharge circuit includes drive module, and the detection module and the release module connected with drive module respectively, and the detection module still is connected with the power grid, and the release module is connected with the bus capacitor, and drive module is still used for receiving off -grid signal. Detection module is used for detecting the input voltage of power grid, and when not detecting the input voltage of power grid, determines that energy storage power supply is not in the grid -connected state, thereby exports first control signal to drive module, drive module is used for when receiving first control signal and off -grid signal is first state, determines that energy storage power supply is not in the off -grid state, exports drive signal to release module at this moment to make release module start to release the capacitor voltage of bus capacitor. Based on this, namely, can when determining energy storage power supply for work, can the bus capacitor fast discharge, thereby has improved the safety of energy storage power supply, and has improved the efficiency of energy storage power supply.

Description

Technical Field

[0001] This utility model relates to the technical field of energy storage power supplies, and in particular to a discharge circuit and an energy storage power supply. Background Technology

[0002] In power electronic equipment, the safe discharge of the DC bus (BUS) is a critical aspect of ensuring equipment maintenance and operational safety. Traditional BUS discharge circuits often rely on digital signal processors (DSPs) for discharge control. This approach not only increases hardware costs and system complexity but also carries the risk of discharge failure due to DSP malfunction. Furthermore, some circuits employ a passive discharge method by connecting a resistor in parallel with the BUS capacitor. While simple to implement, this method continuously generates power losses during normal equipment operation, reducing system energy efficiency. Simultaneously, existing technologies struggle to simultaneously achieve real-time detection and rapid response to the AC side's charging and discharging status, failing to meet the higher requirements of power electronic equipment for discharge efficiency and safety. Therefore, to reduce the cost of energy storage power supplies and improve the discharge efficiency of the DC bus, it is necessary to provide a new discharge circuit. Utility Model Content

[0003] This utility model provides a discharge circuit and an energy storage power supply, aiming to solve the technical problems of high cost and low efficiency when discharging DC bus in the existing energy storage power supply.

[0004] To solve the above-mentioned technical problems, one technical solution adopted by this utility model is to provide a discharge circuit, which includes a detection module, a driving module and a discharge module.

[0005] The detection module is connected to the drive module, the drive module is connected to the discharge module, the detection module is also used to connect to the power grid, the discharge module is used to connect to the bus capacitor, and the drive module is also used to receive off-grid signals.

[0006] The detection module is used to detect the input voltage of the power grid, and when no input voltage of the power grid is detected, it outputs a first control signal to the drive module;

[0007] The drive module is used to output a drive signal to the discharge module when it receives the first control signal and the off-grid signal is in the first state, so that the discharge module starts to work and discharges the capacitor voltage of the bus capacitor.

[0008] Optionally, the detection module is further configured to output a second control signal when the input voltage of the power grid is detected;

[0009] The drive module is also used to stop outputting the drive signal when the off-grid signal is in the second state or when the second control signal is received, so as to stop discharging the capacitor voltage.

[0010] Optionally, the detection module includes a sampling unit, a detection unit, and a control unit;

[0011] The detection unit is connected to the sampling unit and the control unit respectively. The control unit is also connected to the drive module. The sampling unit is also used to connect to the power grid. The detection unit and the control unit are also connected to a reference power supply.

[0012] The sampling unit is used to collect the input voltage of the power grid and output a corresponding voltage signal based on the state of the input voltage;

[0013] The detection unit is used to receive the voltage signal and, when the voltage signal is greater than the reference voltage corresponding to the reference power supply, output a first signal to the control unit; and

[0014] When the voltage signal is less than the reference voltage, a second signal is output to the control unit;

[0015] The control unit is configured to continuously output a second control signal based on the reference power supply when receiving the first signal; and

[0016] After receiving the second signal for a preset time, the first control signal is output to the drive module.

[0017] Optionally, the sampling unit includes a comparator U1, resistors R3, R5, R4, R15, and capacitor C4;

[0018] The two input terminals of the comparator U1 are respectively connected to the power grid. The non-inverting input terminal of the comparator U1 is also connected to the reference power supply through the resistors R4 and R15. The resistor R15 is also grounded through the resistor R3. The inverting input terminal of the comparator U1 is connected to the output terminal of the comparator U1 through the resistor R5. The capacitor C4 is connected in parallel with the resistor R5. The output terminal of the comparator U1 is connected to the detection unit.

[0019] Optionally, the control unit includes a switch Q1, a switch Q2, a resistor R7, a resistor R8, a resistor R9, a resistor R10, and a capacitor C1;

[0020] The control terminal of the switching transistor Q1 is connected to the detection unit. The first terminal of the switching transistor Q1 is connected to the reference power supply through the resistor R7. The second terminal of the switching transistor Q1 is connected to the control terminal of the capacitor C1 and the switching transistor Q2 respectively. The capacitor C1 is also used for grounding. The resistor R8 is connected in parallel with the capacitor C1. The first terminal of the switching transistor Q2 is connected to the reference power supply through the resistor R9. The second terminal of the switching transistor Q2 is grounded through the resistor R10. The second terminal of the switching transistor Q2 is also connected to the drive module.

[0021] Optionally, the driving module is a NOR gate U3;

[0022] The first input terminal of the NOR gate U3 is connected to the detection module, the second input terminal of the NOR gate U3 is used to receive the off-grid signal, and the output terminal of the NOR gate U3 is connected to the discharge module.

[0023] Optionally, the discharge module includes a first discharge unit, a second discharge unit, and a detection and control unit;

[0024] The detection and control unit is connected to the first discharge unit and the second discharge unit respectively. The detection and control unit and the second discharge unit are also connected to the drive module. The first discharge unit and the second discharge unit are also connected to the bus capacitor. The detection and control unit is also connected to the reference power supply.

[0025] The first discharge unit is used to receive the drive signal and start working based on the drive signal to discharge the capacitor voltage of the bus capacitor;

[0026] The detection and control unit is configured to receive and store the capacitor voltage when the first discharge unit discharges the capacitor voltage, and control the second discharge unit to start working when the stored capacitor voltage is greater than the reference voltage of the reference power supply, so that the second discharge unit and the first discharge unit simultaneously discharge the capacitor voltage of the bus capacitor; and

[0027] When the stored capacitor voltage is less than the reference voltage, the second discharge unit is controlled to stop working, so that the second discharge unit stops discharging the capacitor voltage of the bus capacitor.

[0028] Optionally, the first discharge unit includes resistors R12, R13, and R14, and a switching transistor Q4;

[0029] The control terminal of the switch Q4 is connected to the drive module. The first terminal of the switch Q4 is connected to the bus capacitor through the resistors R12 and R13. The second terminal of the switch Q4 is grounded through the resistor R14. The second terminal of the switch Q4 is also connected to the detection and control unit.

[0030] Optionally, the detection control unit includes an AND gate U4, a comparator U5, and a capacitor C2;

[0031] The capacitor C2 is connected to the first discharge unit and the second input terminal of the comparator U5 respectively. The capacitor C2 is also used for grounding. The first input terminal of the comparator U5 is connected to the reference power supply. The output terminal of the comparator U5 is connected to the second input terminal of the AND gate U4. The first input terminal of the AND gate U4 is connected to the driving module. The output terminal of the AND gate U4 is connected to the second discharge unit.

[0032] 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:

[0033] Bus capacitors; and

[0034] The discharge circuit described above.

[0035] Unlike related technologies, this utility model provides a discharge circuit and an energy storage power supply. The discharge circuit includes a detection module, a drive module, and a discharge module. The detection module is connected to the drive module, and the drive module is connected to the discharge module. The detection module is also used to connect to the power grid, and the discharge module is used to connect to the bus capacitor. The drive module is also used to receive off-grid signals. The detection module detects the input voltage of the power grid and, when no input voltage is detected, determines that the energy storage power supply is not in a grid charging state, thereby outputting a first control signal to the drive module. The drive module, upon receiving the first control signal and when the off-grid signal is in a first state, determines that the energy storage power supply is not in a charging state, and then outputs a drive signal to the discharge module to start the discharge module, thereby discharging the capacitor voltage of the bus capacitor. Based on this, the current state of the energy storage power supply can be determined in real time, and the bus capacitor can be quickly discharged when not charging, thus improving the safety and efficiency of the energy storage power supply. Attached Figure Description

[0036] 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.

[0037] Figure 1 This is an application scenario of an energy storage power supply provided by an embodiment of the present invention;

[0038] Figure 2 This is a structural block diagram of a discharge circuit provided in an embodiment of the present invention;

[0039] Figure 3 This is a circuit diagram of the detection module provided in an embodiment of the present invention;

[0040] Figure 4 This is a circuit diagram of a discharge circuit provided in an embodiment of this utility model. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Please see Figure 1 , Figure 1 This is an application scenario of an energy storage power supply provided by an embodiment of the present invention, such as... Figure 1As shown, application scenario 1 includes an energy storage power supply 100, a power grid 200, and a load 300. The energy storage power supply 100 is connected to both the power grid 200 and the load 300. When the power grid 200 is connected to the energy storage power supply 100, the energy storage power supply 100 is in a grid-connected state. At this time, the energy storage power supply 100 receives the grid voltage, converts the grid voltage into a target voltage, and outputs it to the load 300 to supply power to the load 300. The energy storage power supply 100 includes a battery 10 and a controller 20, with the battery 10 connected to the controller 20. When the power grid 200 is not connected to the energy storage power supply 100, the energy storage power supply 100 does not detect the input voltage of the power grid 200. In this case, if the energy storage power supply 100 needs to supply power to the load 300, the controller 20 will control the battery 10 to start releasing battery voltage to supply power to the load 300 based on the battery voltage.

[0047] In yet another embodiment, such as Figure 1 As shown, the energy storage power supply 100 also includes a bus capacitor EC1. When the energy storage power supply 100 supplies power to the load 300 based on the input voltage of the grid 200 or the battery voltage of the battery 10, the bus capacitor EC1 also stores a large amount of electrical energy. If the power supply to the load 300 is stopped at this time, the electrical energy stored in the bus capacitor EC1 needs to be discharged to improve the service life of the bus capacitor EC1. Based on this, the energy storage power supply 100 in this embodiment also includes a discharge circuit 30. The discharge circuit 30 is connected to the bus capacitor EC1 and is also connected to the controller 20 and the grid 200. The discharge circuit 30 is used to detect whether the grid 200 and the battery 10 are in a discharging state. When no input voltage is received from the grid 200 and the off-grid signal output by the controller 20 is in the first state, it is determined that the load 300 is not in a charging state, that is, the bus capacitor EC1 is not in a charging state. At this time, the discharge circuit 30 will start working to discharge the voltage stored in the bus capacitor EC1, thereby improving the safety and service life of the energy storage power supply 100.

[0048] It should be noted that the off-grid signal includes a first state and a second state. When the off-grid signal is in the first state, the energy storage power supply 100 is considered to be in an off-grid state, meaning the battery 10 is not outputting voltage. Simultaneously, if the discharge circuit 30 also does not receive input voltage from the grid 200, the energy storage power supply 100 is considered to be in an off-grid state. At this time, the discharge circuit 30 starts operating, discharging the bus capacitor EC1. However, if the off-grid signal is in the second state, or if the discharge circuit 30 receives input voltage from the grid 200, the battery 10 / grid 200 is considered to be supplying power to the load 300. In this case, the discharge circuit 30 stops operating to avoid damaging the bus capacitor EC1, thereby extending the service life of the energy storage power supply 100.

[0049] In some embodiments, please refer to Figure 2 , Figure 2 This is a structural block diagram of a discharge circuit provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the discharge circuit 30 includes a detection module 31, a driving module 32, and a discharge module 33;

[0050] The detection module 31 is connected to the drive module 32, the drive module 32 is connected to the discharge module 33, the detection module 31 is also used to connect to the power grid 200, the discharge module 33 is used to connect to the bus capacitor EC1, and the drive module 32 is also used to receive off-grid signals.

[0051] The detection module 31 is used to detect the input voltage of the power grid 200, and when the input voltage of the power grid 200 is not detected, it outputs a first control signal to the drive module 32;

[0052] The drive module 32 is used to output a drive signal to the discharge module 33 when it receives the first control signal and the off-grid signal is in the first state, so that the discharge module 33 starts to work and discharges the capacitor voltage of the bus capacitor EC1.

[0053] Specifically, when it is necessary to discharge the bus capacitor EC1, the detection module 31 will detect whether there is an input voltage in the grid 200 (i.e., whether the grid 200 is connected to the energy storage power supply 100). If no input voltage is detected, it is considered that the energy storage power supply 100 is not in a grid-connected state. At this time, the detection module 31 will output a first control signal to the drive module 32. At the same time, the drive module 32 will also receive the off-grid signal output by the controller 20. If the off-grid signal is in the first state, the drive module 32 will output a drive signal to the discharge module 33 so that the discharge module 33 starts working according to the drive signal. After the discharge module 33 starts working, the voltage stored in the bus capacitor EC1 can be discharged through the discharge module 33, thereby preventing the bus capacitor EC1 from being in a high-voltage state continuously, and thus extending the service life of the bus capacitor EC1.

[0054] In some embodiments, if the detection module 31 detects the input voltage of the power grid 200, it considers the energy storage power supply 100 to be in a grid-connected state. At this time, the detection module 31 will output a second control signal to the drive module 32 so that the drive module 32 controls the discharge module 33 to stop discharging the capacitor voltage of the bus capacitor EC1.

[0055] In another embodiment, when the off-grid signal received by the drive module 32 is in the second state, the energy storage power supply 100 is considered to be in an off-grid state. At this time, the bus capacitor EC1 stores the output voltage of the battery 10. Therefore, in order to avoid damaging the bus capacitor EC1, the drive module 32 will stop outputting drive signals to the discharge module 33, so that the discharge module 33 stops working. Based on this, the discharge of the bus capacitor EC1 during the charging state (grid-connected charging or off-grid charging) can be avoided, thereby improving the reliability of the energy storage power supply 100.

[0056] In some embodiments, such as Figure 2 As shown, the detection module 31 includes a sampling unit 311, a detection unit 312, and a control unit 313;

[0057] The detection unit 312 is connected to the sampling unit 311 and the control unit 313 respectively. The control unit 313 is also connected to the drive module 32. The sampling unit 311 is also used to connect to the power grid 200. The detection unit 312 and the control unit 313 are also connected to a reference power supply (not shown).

[0058] The sampling unit 311 is used to collect the input voltage of the power grid 200 and output a corresponding voltage signal based on the state of the input voltage;

[0059] The detection unit 312 is used to receive the voltage signal, and when the voltage signal is greater than the reference voltage corresponding to the reference power supply, it outputs a first signal to the control unit 313; and

[0060] When the voltage signal is less than the reference voltage, a second signal is output to the control unit 313;

[0061] The control unit 313 is configured to continuously output a second control signal based on the reference power supply when the first signal is received; and

[0062] After receiving the second signal for a preset time, the first control signal is output to the drive module 32.

[0063] Specifically, during the operation of the energy storage power supply 100, the sampling module 311 detects the input voltage of the power grid 200 in real time and outputs a corresponding voltage signal to the detection unit 312 based on the state of the input voltage. After receiving the voltage signal, the detection unit 312 compares the voltage signal with a reference voltage. If the voltage signal is greater than the reference voltage, it outputs a first signal to the control unit 313. Upon receiving the first signal, the control unit 313 starts working according to the first signal, thereby continuously outputting a second control signal to the drive module 32 based on the reference voltage, so that the drive module 32 controls the discharge module 33 to stop discharging the voltage stored in the bus capacitor EC1.

[0064] It is important to understand that the input voltage of the power grid 200 is alternating current (AC). That is, when the sampling unit 311 acquires the input voltage of the power grid 200, its output voltage signal is a sinusoidal signal. At the negative half-axis of this sinusoidal signal, the voltage signal will be less than the reference voltage. Therefore, when the voltage signal is less than the reference voltage, the detection unit 312 will output a second signal to the control unit 313. When the control unit 313 receives the second signal, if the signal received by the control unit 313 switches from the second signal to the first signal within a preset time, it is considered that the power grid 200 has voltage input, and the control unit 313 will continuously output the second control signal. However, if the control unit 313 continuously receives the second signal within the preset time, it is considered that the power grid 200 has no input voltage, and a first control signal is output to the drive module 32. This causes the drive module 32 to output a drive signal to the discharge module 33 based on the first control signal, thereby controlling the discharge module 33 to start working.

[0065] In other embodiments, please refer to Figure 3 , Figure 3This is a circuit diagram of the detection module provided in an embodiment of this utility model, as shown below. Figure 3 As shown, the sampling unit 311 includes a comparator U1, resistors R3, R5, R4, R15 and capacitor C4; the detection unit 312 includes a comparator U2 and resistor R6; the control unit 313 includes a switch Q1, a switch Q2, resistors R7, R8, R9, R10 and capacitor C1.

[0066] The two input terminals of the comparator U1 are respectively connected to the power grid 200. The non-inverting input terminal of the comparator U1 is also connected to the reference power supply through the resistor R4 and the resistor R15. The resistor R15 is also grounded through the resistor R3. The inverting input terminal of the comparator U1 is connected to the output terminal of the comparator U1 through the resistor R5. The capacitor C4 is connected in parallel with the resistor R5. The output terminal of the comparator U1 is also connected to the detection unit 312.

[0067] The non-inverting input of the comparator U2 is connected to the sampling unit 311 through the resistor R6, the inverting input of the comparator U2 is connected to the reference power supply, and the output of the comparator U2 is connected to the control unit 313.

[0068] The control terminal of the switching transistor Q1 is connected to the detection unit 312. The first terminal of the switching transistor Q1 is connected to the reference power supply through the resistor R7. The second terminal of the switching transistor Q1 is connected to the control terminal of the capacitor C1 and the switching transistor Q2 respectively. The capacitor C1 is also used for grounding. The resistor R8 is connected in parallel with the capacitor C1. The first terminal of the switching transistor Q2 is connected to the reference power supply through the resistor R9. The second terminal of the switching transistor Q2 is grounded through the resistor R10. The second terminal of the switching transistor Q2 is also connected to the drive module 32.

[0069] It should be noted that comparator U1 is a differential comparator. When there is voltage input to the power grid 200, comparator U1 outputs a corresponding voltage signal (sine wave) to the non-inverting input of comparator U2 based on the input voltage (AC). During the positive half-cycle of the sine wave, the voltage at the non-inverting input of comparator U2 will be greater than the voltage at the inverting input, thus outputting a first signal to the control terminal of switch Q1. During the negative half-cycle of the sine wave, the voltage at the non-inverting input of comparator U2 will be less than the voltage at the inverting input, at which point comparator U2 will output a second signal to the control terminal of switch Q1.

[0070] When the power grid 200 is not connected, that is, when the input voltage of the power grid is 0, the voltage at the non-inverting input terminal of the comparator U2 is less than the voltage at the inverting input terminal of the comparator U2, and the comparator U2 will continuously output the second signal.

[0071] When switch Q1 receives the first signal, it will turn on based on the first signal. When switch Q1 turns on, switch Q2 will also turn on, and the reference voltage of the reference power supply will be output to the drive module 32 through switch Q2, that is, the second control signal will be output to the drive module 32. When switch Q1 receives the second signal, it will turn off based on the second signal, and switch Q2 will also turn off, thereby outputting the first control signal to the drive module 32.

[0072] It is known that the sinusoidal signal is a periodic signal, and after passing through the comparator U2, it will output a periodic pulse signal (that is, cyclically outputting the first signal and the second signal). Therefore, when the switch Q1 is turned on based on the first signal, the reference power supply will charge the capacitor C1 through the switch Q1, and the switch Q2 will also be turned on. When the switch Q2 is turned on, it will output a second control signal to the drive module 32. When the switch Q1 is turned off based on the second signal, the capacitor C1 will discharge the resistor R8, and the switch Q2 will also remain on based on the discharge voltage. If the switch Q1 receives the first signal again within a preset time, the switch Q2 will remain on based on the switch Q1, thereby continuously outputting the second control signal; if the switch Q1 continues to receive the second signal, when the voltage stored in the capacitor C1 is less than the on-state voltage drop of the switch Q2, the switch Q2 will be turned off, thereby outputting the first control signal. Based on this, the selection of resistor R8 and capacitor C1 can ensure that the switching transistor Q2 continuously outputs the second control signal during the period of the pulse signal. The preset time is set according to the discharge time of capacitor C1.

[0073] In yet another embodiment, please refer to Figure 4 , Figure 4 This is a circuit diagram of a discharge circuit provided in an embodiment of this utility model, as shown below. Figure 4 As shown, the driving module 32 is a NOR gate U3;

[0074] The first input terminal of the NOR gate U3 is connected to the detection module 31, the second input terminal of the NOR gate U3 is used to receive the off-grid signal, and the output terminal of the NOR gate U3 is connected to the discharge module 33.

[0075] Specifically, when the detection module 31 outputs a first control signal (low level) and the off-grid signal is in a first state (low level), the NOR gate U3 outputs a drive signal (high level signal) to the discharge module 33, causing the discharge module 33 to start working. However, if the detection module 31 outputs a second control signal or the off-grid signal is in a second state, the NOR gate U3 stops outputting the drive signal (i.e., outputs a low level signal), thereby causing the discharge module 33 to stop working.

[0076] In some embodiments, such as Figure 2 As shown, the discharge module 33 includes a first discharge unit 331, a second discharge unit 332, and a detection and control unit 333;

[0077] The detection control unit 333 is connected to the first discharge unit 331 and the second discharge unit 332 respectively. The detection control unit 333 and the second discharge unit 332 are also connected to the drive module 32. The first discharge unit 331 and the second discharge unit 332 are also connected to the bus capacitor EC1. The detection control unit 333 is also connected to the reference power supply.

[0078] The first discharge unit 331 is used to receive the drive signal and start working based on the drive signal to discharge the capacitor voltage of the bus capacitor EC1;

[0079] The detection and control unit 333 is used to receive and store the capacitor voltage when the first discharge unit 331 discharges the capacitor voltage, and to control the second discharge unit 332 to start working when the stored capacitor voltage is greater than the reference voltage of the reference power supply, so that the second discharge unit 332 and the first discharge unit 331 simultaneously discharge the capacitor voltage of the bus capacitor EC1; and

[0080] When the stored capacitor voltage is less than the reference voltage, the second discharge unit 332 is controlled to stop working, so that the second discharge unit 332 stops discharging the capacitor voltage of the bus capacitor EC1.

[0081] Specifically, when the drive module 32 outputs a drive signal, the first discharge unit 331 starts working based on the drive signal, thereby discharging the capacitor voltage of the bus capacitor EC1. While the first discharge unit 331 discharges the capacitor voltage, the capacitor voltage is also input to the detection control unit 333 to charge the detection control unit 333. When the voltage stored in the detection control unit 333 is greater than the reference voltage, the detection control unit 333 controls the second discharge unit 332 to start working, so that the second discharge unit 332 also begins discharging the capacitor voltage of the bus capacitor EC1. At this time, because the first discharge unit 331 and the second discharge unit 332 discharge the capacitor voltage simultaneously, the discharge speed is increased.

[0082] It is understood that during the charging process of the detection control unit 333 based on the capacitor voltage of the bus capacitor EC1, if the capacitor voltage of the bus capacitor EC1 is less than the voltage stored in the detection control unit 333, then the bus capacitor EC1 cannot charge the detection control unit 333. At this time, the detection control unit 333 begins to discharge. During the discharge process of the detection control unit 333, if the voltage stored in the detection control unit 333 is less than the reference voltage, then the detection control unit 333 will control the second discharge unit 332 to stop working. At this time, only the first discharge power supply 331 discharges the capacitor voltage of the bus capacitor EC1, thereby slowing down the discharge rate of the bus capacitor EC1.

[0083] In another embodiment, such as Figure 4 As shown, the first discharge unit 331 includes resistors R12, R13, and R14, and a switch Q4; the second discharge unit 332 includes resistor R11 and a switch Q3; the detection and control unit 333 includes an AND gate U4, a comparator U5, and a capacitor C2.

[0084] The control terminal of the switch Q4 is connected to the drive module 32. The first terminal of the switch Q4 is connected to the bus capacitor EC1 through the resistors R12 and R13. The second terminal of the switch Q4 is grounded through the resistor R14. The second terminal of the switch Q4 is also connected to the detection control unit 333.

[0085] The control terminal of the switch Q3 is connected to the detection and control unit 333. The first terminal of the switch Q3 is connected to the bus capacitor EC1 through the resistor R11, and the second terminal of the switch Q3 is used for grounding.

[0086] The capacitor C2 is connected to the first discharge unit 331 and the second input terminal of the comparator U5 respectively. The capacitor C2 is also used for grounding. The first input terminal of the comparator U5 is connected to the reference power supply. The output terminal of the comparator U5 is connected to the second input terminal of the AND gate U4. The first input terminal of the AND gate U4 is connected to the driving module 32. The output terminal of the AND gate U4 is connected to the second discharge unit 332.

[0087] When the driving module 32 outputs a driving signal, the AND gate U4 receives the driving signal at its first input terminal, and the control terminal of the switch Q4 also receives the driving signal. Upon receiving the driving signal, the switch Q4 turns on. When the switch Q4 turns on, the voltage across the bus capacitor EC1 is discharged through resistors R12, R13, and R14; simultaneously, this voltage flows into capacitor C2 through resistors R12 and R13 and the switch Q4 to charge capacitor C2. When the voltage stored in capacitor C2 exceeds the reference voltage, the comparator U5 outputs a high-level signal to the second input terminal of the AND gate U4. Upon receiving this high-level signal, the AND gate U4 controls the switch Q3 to turn on. When the switch Q3 turns on, resistor R11 is connected in parallel with resistors R12, R13, and R14, thereby accelerating the discharge.

[0088] After resistor R11 participates in the discharge, as the voltage of bus capacitor EC1 gradually decreases, the voltage stored in capacitor C2 will exceed the voltage of bus capacitor EC1. Capacitor C2 will then stop charging and begin discharging through resistor R14. During the discharge of capacitor C2, the voltage stored in capacitor C2 gradually decreases. When the voltage stored in capacitor C2 is less than the reference voltage, comparator U5 will output a low-level signal. When the second input of AND gate U4 receives the low-level signal, it controls the switch Q3 to turn off, thereby stopping the second discharge unit 332 from discharging bus capacitor EC1. Based on this, the discharge rate can be switched in a timely manner according to the charge level of bus capacitor EC1, thereby improving the reliability of the energy storage power supply.

[0089] This utility model embodiment provides a discharge circuit, which includes a detection module, a drive module, and a discharge module. The detection module is connected to the drive module, and the drive module is connected to the discharge module. The detection module is also used to connect to the power grid, and the discharge module is used to connect to the bus capacitor. The drive module is also used to receive off-grid signals. The detection module detects the input voltage of the power grid and, when no input voltage is detected, determines that the energy storage power supply is not in a grid charging state, thereby outputting a first control signal to the drive module. The drive module, upon receiving the first control signal and when the off-grid signal is in a first state, determines that the energy storage power supply is not in a charging state, and then outputs a drive signal to the discharge module to start the discharge module, thereby discharging the capacitor voltage of the bus capacitor. Based on this, the current state of the energy storage power supply can be determined in real time, and the bus capacitor can be quickly discharged when not charging, thereby improving the safety and efficiency of the energy storage power supply.

[0090] 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 discharge circuit, characterized in that, The discharge circuit includes a detection module, a driving module, and a discharge module; The detection module is connected to the drive module, the drive module is connected to the discharge module, the detection module is also used to connect to the power grid, the discharge module is used to connect to the bus capacitor, and the drive module is also used to receive off-grid signals. The detection module is used to detect the input voltage of the power grid, and when no input voltage of the power grid is detected, it outputs a first control signal to the drive module; The drive module is used to output a drive signal to the discharge module when it receives the first control signal and the off-grid signal is in the first state, so that the discharge module starts to work and discharges the capacitor voltage of the bus capacitor.

2. The discharge circuit according to claim 1, characterized in that, The detection module is also used to output a second control signal when the input voltage of the power grid is detected; The drive module is also used to stop outputting the drive signal when the off-grid signal is in the second state or when the second control signal is received, so as to stop discharging the capacitor voltage.

3. The discharge circuit according to claim 2, characterized in that, The detection module includes a sampling unit, a detection unit, and a control unit; The detection unit is connected to the sampling unit and the control unit respectively. The control unit is also connected to the drive module. The sampling unit is also used to connect to the power grid. The detection unit and the control unit are also connected to a reference power supply. The sampling unit is used to collect the input voltage of the power grid and output a corresponding voltage signal based on the state of the input voltage; The detection unit is used to receive the voltage signal and output a first signal to the control unit when the voltage signal is greater than the reference voltage corresponding to the reference power supply; as well as When the voltage signal is less than the reference voltage, a second signal is output to the control unit; The control unit is configured to continuously output a second control signal based on the reference power supply when it receives the first signal; as well as After receiving the second signal for a preset time, the first control signal is output to the drive module.

4. The discharge circuit according to claim 3, characterized in that, The sampling unit includes a comparator U1, resistors R3, R5, R4, R15, and capacitor C4; The two input terminals of the comparator U1 are respectively connected to the power grid. The non-inverting input terminal of the comparator U1 is also connected to the reference power supply through the resistors R4 and R15. The resistor R15 is also grounded through the resistor R3. The inverting input terminal of the comparator U1 is connected to the output terminal of the comparator U1 through the resistor R5. The capacitor C4 is connected in parallel with the resistor R5. The output terminal of the comparator U1 is connected to the detection unit.

5. The discharge circuit according to claim 3, characterized in that, The control unit includes a switch Q1, a switch Q2, a resistor R7, a resistor R8, a resistor R9, a resistor R10, and a capacitor C1; The control terminal of the switching transistor Q1 is connected to the detection unit. The first terminal of the switching transistor Q1 is connected to the reference power supply through the resistor R7. The second terminal of the switching transistor Q1 is connected to the control terminal of the capacitor C1 and the switching transistor Q2 respectively. The capacitor C1 is also used for grounding. The resistor R8 is connected in parallel with the capacitor C1. The first terminal of the switching transistor Q2 is connected to the reference power supply through the resistor R9. The second terminal of the switching transistor Q2 is grounded through the resistor R10. The second terminal of the switching transistor Q2 is also connected to the drive module.

6. The discharge circuit according to any one of claims 1-5, characterized in that, The driving module is a NOR gate U3; The first input terminal of the NOR gate U3 is connected to the detection module, the second input terminal of the NOR gate U3 is used to receive the off-grid signal, and the output terminal of the NOR gate U3 is connected to the discharge module.

7. The discharge circuit according to claim 6, characterized in that, The discharge module includes a first discharge unit, a second discharge unit, and a detection and control unit; The detection and control unit is connected to the first discharge unit and the second discharge unit respectively. The detection and control unit and the second discharge unit are also connected to the drive module. The first discharge unit and the second discharge unit are also connected to the bus capacitor. The detection and control unit is also connected to the reference power supply. The first discharge unit is used to receive the drive signal and start working based on the drive signal to discharge the capacitor voltage of the bus capacitor; The detection and control unit is used to receive and store the capacitor voltage when the first discharge unit discharges the capacitor voltage, and when the stored capacitor voltage is greater than the reference voltage of the reference power supply, control the second discharge unit to start working so that the second discharge unit and the first discharge unit discharge the capacitor voltage of the bus capacitor at the same time. as well as When the stored capacitor voltage is less than the reference voltage, the second discharge unit is controlled to stop working, so that the second discharge unit stops discharging the capacitor voltage of the bus capacitor.

8. The discharge circuit according to claim 7, characterized in that, The first discharge unit includes resistors R12, R13, and R14, and a switching transistor Q4; The control terminal of the switch Q4 is connected to the drive module. The first terminal of the switch Q4 is connected to the bus capacitor through the resistors R12 and R13. The second terminal of the switch Q4 is grounded through the resistor R14. The second terminal of the switch Q4 is also connected to the detection and control unit.

9. The discharge circuit according to claim 7, characterized in that, The detection and control unit includes an AND gate U4, a comparator U5, and a capacitor C2; The capacitor C2 is connected to the first discharge unit and the second input terminal of the comparator U5 respectively. The capacitor C2 is also used for grounding. The first input terminal of the comparator U5 is connected to the reference power supply. The output terminal of the comparator U5 is connected to the second input terminal of the AND gate U4. The first input terminal of the AND gate U4 is connected to the driving module. The output terminal of the AND gate U4 is connected to the second discharge unit.

10. An energy storage power source, characterized in that, The energy storage power source includes: Bus capacitors; and The discharge circuit as described in any one of claims 1-9.

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