Hot plug discharge circuit and energy storage system thereof
By designing a hot-swappable discharge circuit in the photovoltaic power generation system, and using a control module to detect voltage and current changes to generate a discharge signal, the energy storage module is quickly discharged, solving the contactor damage problem caused by arc discharge and ensuring system safety and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-20
- Publication Date
- 2026-03-13
AI Technical Summary
In photovoltaic power generation systems, during hot-plugging operations between PV modules and controllers, the charge of electrolytic capacitors discharges in the reverse direction through relay contacts, causing arcing, which damages the contactor and reduces its conductivity and mechanical strength.
Design a hot-swappable discharge circuit, including an input module, a conversion module, a switching module, an energy storage module, a pre-charge module, a control module, and a discharge module. The control module detects changes in input voltage and current to generate a discharge enable signal, and controls the discharge module to quickly discharge the energy storage module to disconnect the switching module.
It effectively avoids arcing during hot-swapping, prevents oxidation of input port contacts, and protects the normal operation of the system.
Smart Images
Figure CN223993562U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic energy storage, and in particular to a hot-swappable discharge circuit and its energy storage system. Background Technology
[0002] In photovoltaic (PV) power generation systems, the connection between the PV module and the controller requires a dedicated interface. During normal charging, the PV interface carries the energy transfer from the PV module to the system. When the system is operating normally, the boost / buck converter in the circuit converts the electrical energy input from the PV into a voltage level suitable for the storage system, and uses electrolytic capacitors to buffer the energy, smoothing current fluctuations and stabilizing the system voltage.
[0003] When performing hot-swapping operations on the PV interface (i.e., removing or inserting the PV connector while it is energized), the following problem occurs: After the PV interface is removed, the relay takes tens of milliseconds to fully disconnect due to mechanical inertia. During this brief time window, the electrolytic capacitor in the circuit remains electrically connected to the input terminal. At this time, the input voltage suddenly drops (even to zero), while the electrolytic capacitor still retains a high voltage charge. This voltage difference causes the charge in the electrolytic capacitor to discharge in reverse to the input terminal through the relay contacts. When the user reinserts the PV connector before the relay has fully disconnected, the energized conductor of the external PV module comes into contact with the already charged input terminal. Due to the instantaneous potential difference and current surge, a strong arc discharge (sparking) occurs at the contact point. The arc can not only cause the contactor to reach instantaneous high temperatures, but also cause oxidation, melting, or ablation of the connector's metal surface (usually copper), gradually reducing the contactor's conductivity and mechanical strength. Utility Model Content
[0004] The main technical problem solved by this utility model embodiment is to provide a hot-swappable discharge circuit and its energy storage system, which can solve at least some of the defects of existing photovoltaic power generation systems.
[0005] To address the aforementioned technical problems, in a first aspect, this utility model provides a hot-swappable discharge circuit, comprising: an input module configured to receive photovoltaic power input; a conversion module configured to convert the input voltage of the input module; a switch module connected between the input module and the conversion module, configured to receive the input voltage and output the input voltage when turned on; an energy storage module connected to the switch module, configured to store electrical energy; a pre-charge module connected between the input module and the conversion module, configured to pre-charge the energy storage module when the input voltage is received; a control module connected to the switch module, configured to generate a discharge enable signal based on the input voltage and the input current of the input module; and a discharge module connected to the energy storage module and the control module, configured to discharge the energy storage module in response to the discharge enable signal, thereby disconnecting the switch module.
[0006] Optionally, the control module includes: a voltage detection unit connected to the input module, configured to generate a voltage detection signal when the input voltage is lower than a preset voltage threshold; a current detection unit connected to the input module, configured to generate a current detection signal when the input current of the input module is less than a preset current threshold; and a logic unit connected to the voltage detection unit, the current detection unit, and the discharge module, configured to generate the discharge enable signal in response to the voltage detection signal and the current detection signal.
[0007] Optionally, the voltage detection unit includes resistors R14, R15, R16, R18, R19, and R20, capacitors C7, C8, and C9, operational amplifiers U1B and U2B. The non-inverting input of operational amplifier U1B is connected to the first terminal of capacitor C7, the first terminal of resistor R16, and the first terminal of resistor R18. The inverting input of operational amplifier U1B is connected to the first terminal of resistor R19, the first terminal of resistor R20, and the first terminal of capacitor C9. The output of operational amplifier U1B is connected to the second terminal of resistor R20 and capacitor C9. The second terminal of the resistor R18 is connected to the inverting input terminal of the operational amplifier U2B; the non-inverting input terminal of the operational amplifier U2B is connected to the first terminal of the resistor R14 and the first terminal of the resistor R15; the output terminal of the operational amplifier U2B is connected to the first input terminal of the logic unit; the second terminal of the resistor R18 is connected to the first terminal of the capacitor C8 and the output terminal of the input module; the second terminal of the resistor R19 and the second terminal of the capacitor C8 are connected to the first reference ground; the second terminal of the resistor R14 is connected to the first voltage source; and the second terminals of the capacitor C7, the second terminals of the resistor R16 and the second terminals of the resistor R15 are connected to the second reference ground.
[0008] Optionally, the current detection unit includes resistors R21, R22, R24, R25, R26, R27, R28, and R29, capacitors C10, C11, and C12, operational amplifier U1C, and operational amplifier U2C. The non-inverting input terminal of operational amplifier U1C is connected to the first terminal of capacitor C1, the first terminal of resistor R24, and the first terminal of resistor R25. The inverting input terminal of operational amplifier U1C is connected to the first terminal of resistor R26, the first terminal of resistor R27, and the first terminal of capacitor C12. The output terminal of operational amplifier U1C is connected to the second terminal of resistor R27, the second terminal of capacitor C12, and the first terminal of operational amplifier U2C. The inverting input of amplifier U2C is connected; the non-inverting input of operational amplifier U2C is connected to the first terminal of resistor R21 and the first terminal of resistor R22; the output of operational amplifier U2C is connected to the second input of the logic unit; the second terminal of resistor R21 is connected to the first voltage source; the second terminals of resistor R26, capacitor C11, resistor R28, and resistor R29 are connected to the first reference ground; the second terminals of resistor R22, resistor R24, resistor R25, resistor R28, resistor R29, capacitor C10, and capacitor C11 are connected to the second reference ground.
[0009] Optionally, the logic unit includes an AND gate U3B, a resistor R17, and a resistor R23. The first input terminal of the AND gate U3B, the first terminal of the resistor R17, and the output terminal of the voltage detection unit are connected. The second input terminal of the AND gate U3B, the first terminal of the resistor R23, and the output terminal of the current detection unit are connected. The output terminal of the AND gate U3B is connected to the controlled terminal of the discharge module. The second terminals of the resistor R17 and the second terminals of the resistor R23 are connected to a first voltage source.
[0010] Optionally, the discharge module includes a discharge resistor RW1, a switching transistor Q3, and a resistor R9. The first end of the discharge resistor RW1 is connected to the energy storage module, the second end of the discharge resistor RW1 is connected to the drain of the switching transistor Q3, the gate of the switching transistor Q3 is connected to the first end of the resistor R9 and the output terminal of the control module, and the source of the switching transistor Q3 and the second end of the resistor R9 are connected to a second reference ground.
[0011] Optionally, the switching module includes a relay RLY1, a diode D3, a switching transistor Q4, a resistor R7, and a resistor R11. The first terminal of the relay RLY1 is connected to the output terminal of the input module, the second terminal of the relay RLY1 is connected to the input terminal of the conversion module, the first terminal of the coil of the relay RLY1 is connected to the cathode of the diode D3 and a second voltage source, the second terminal of the coil of the relay RLY1 is connected to the cathode of the diode D2 and the collector of the switching transistor Q4, the base of the switching transistor Q4 is connected to the first terminal of the resistor R7 and the first terminal of the resistor R11, the second terminal of the resistor R7 is connected to a photovoltaic enable signal, and the second terminal of the resistor R11 and the emitter of the switching transistor Q4 are connected to a second reference ground.
[0012] Optionally, the pre-charge module includes a diode D1 and a thermistor RT1. The anode of the diode D1 is connected to the output terminal of the input module, the cathode of the diode D1 is connected to the first terminal of the thermistor RT1, and the second terminal of the thermistor RT1 is connected to the energy storage module.
[0013] Optionally, the energy storage module includes an electrolytic capacitor EC2, with the first terminal of the electrolytic capacitor EC2 connected to the output terminal of the precharge module, and the second terminal of the electrolytic capacitor EC2 connected to a second reference ground.
[0014] Secondly, embodiments of the present invention provide an energy storage system, including: a hot-swappable discharge circuit as described in the first aspect.
[0015] The beneficial effects of this utility model embodiment are as follows: Unlike the prior art, this utility model embodiment detects the input voltage through the control module, and outputs a discharge enable signal when the input voltage is detected to be disconnected, thereby controlling the discharge module to quickly discharge the energy storage module to quickly disconnect the switching module, thereby avoiding the arcing phenomenon caused by hot plugging and effectively preventing the oxidation of the input port contacts. Attached Figure Description
[0016] 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.
[0017] Figure 1 This is a schematic diagram of the structure of a hot-swappable discharge circuit provided by an embodiment of this utility model;
[0018] Figure 2 This is a schematic diagram of the structure of a control module provided in an embodiment of this utility model;
[0019] Figure 3 This is a circuit diagram of a hot-swappable discharge circuit provided by an embodiment of the present invention;
[0020] Figure 4 This is a circuit diagram of a control module provided by an embodiment of the present invention. Detailed Implementation
[0021] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this specification are for illustrative purposes only.
[0022] 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.
[0023] In the description of this utility model, unless otherwise stated, "connection" can refer to a direct connection or an indirect connection through an intermediate element. Terms such as "first" and "second" are used to distinguish different elements or operations, not to describe a specific order or importance. "Hot-plugging" refers to the operation of removing or inserting a connector while the system is energized. "Pre-charging" refers to the process of slowly charging the energy storage module to avoid instantaneous large currents. "Reference ground" refers to the common potential point in the circuit.
[0024] Please refer to Figure 1 This utility model embodiment provides a hot-swappable discharge circuit, including: an input module 100, a conversion module 700, a switch module 200, an energy storage module 400, a pre-charge module 300, a control module 600, and a discharge module 500.
[0025] The input module 100 is configured to receive photovoltaic power input. In some embodiments, the input module 100 may be connected to a photovoltaic array or other photovoltaic power generation equipment to receive electrical energy converted from solar energy.
[0026] The conversion module 700 is configured to convert the input voltage of the input module 100. By way of example and not limitation, the conversion module 700 may be a boost or buck converter used to convert the input voltage of the photovoltaic source into the operating voltage required by the downstream equipment.
[0027] The switch module 200 is connected between the input module 100 and the conversion module 700, and is configured to receive the input voltage and output the input voltage when it is turned on. In some embodiments, the switch module 200 may include a switching element such as a relay for controlling whether the input voltage is transmitted to the conversion module 700.
[0028] The energy storage module 400 is connected to the switch module 200 and is configured to store electrical energy. In some embodiments, the energy storage module 400 may include components such as electrolytic capacitors to smooth current fluctuations and stabilize system voltage.
[0029] The pre-charge module 300 is connected between the input module 100 and the conversion module 700 and is configured to pre-charge the energy storage module 400 when it receives an input voltage. The pre-charge module 300 can slowly charge the energy storage module 400 through a current-limiting element during system startup or reconnection of the photovoltaic input, preventing the instantaneous large current from impacting the conversion module 700 when the switching module 200 is turned on.
[0030] The control module 600 is connected to the switch module 200 and is configured to generate a discharge enable signal based on the input voltage and the input current of the input module 100. Specifically, the control module 600 can monitor changes in the input voltage and input current, and generate a discharge enable signal when it detects that the input terminal is disconnected (e.g., PV hot-plugged out).
[0031] The discharge module 500 is connected to the energy storage module 400 and the control module 600, and is configured to discharge the energy storage module 400 in response to a discharge enable signal, thereby causing the switch module 200 to disconnect. Upon receiving the discharge enable signal, the discharge module 500 can quickly release the energy in the energy storage module 400 through the discharge path, ensuring that the switch module 200 can disconnect in a timely manner, thus avoiding arcing during hot-swapping.
[0032] In this embodiment, when the photovoltaic input is normal, the pre-charge module 300 first pre-charges the energy storage module 400, and then the switch module 200 is turned on, allowing the energy storage system to enter normal operation. When the photovoltaic input is disconnected, the control module 600 detects a decrease in input voltage and a decrease in input current, and immediately generates a discharge enable signal. Upon receiving this signal, the discharge module 500 quickly discharges the energy in the energy storage module 400, enabling the switch module 200 to quickly disconnect. This avoids arcing caused by reverse discharge of energy in the energy storage module 400 during hot-swapping, effectively protecting the contactor at the input port.
[0033] Please refer to Figure 2 In one embodiment of the present invention, the control module 600 includes a voltage detection unit 610, a current detection unit 620, and a logic unit 630.
[0034] The voltage detection unit 610 is connected to the input module 100 and is configured to generate a voltage detection signal when the input voltage is lower than a preset voltage threshold. In some embodiments, the voltage detection unit 610 can be implemented by a comparator circuit, which outputs a high-level voltage detection signal when the input voltage is detected to drop below the preset threshold (e.g., when the photovoltaic connection is disconnected).
[0035] The current detection unit 620 is connected to the input module 100 and is configured to generate a current detection signal when the input current of the input module 100 is less than a preset current threshold. The current detection unit 620 can detect changes in the input current through a sampling resistor and a signal amplification circuit. When the input current drops below the preset threshold (for example, when the photovoltaic connection is disconnected), it outputs a high-level current detection signal.
[0036] The logic unit 630 is connected to the voltage detection unit 610, the current detection unit 620, and the discharge module 500, and is configured to generate a discharge enable signal in response to the voltage detection signal and the current detection signal. In some embodiments, the logic unit 630 can be implemented by a logic gate circuit, such as an AND gate circuit, which outputs a high-level discharge enable signal to the discharge module 500 when both the voltage detection signal and the current detection signal are received simultaneously.
[0037] In practical applications, when the photovoltaic interface is unplugged, the voltage detection unit 610 detects a rapid drop in the input voltage and generates a voltage detection signal; at the same time, the current detection unit 620 detects a decrease in the input current and generates a current detection signal; after receiving the voltage detection signal and the current detection signal, the logic unit 630 generates a discharge enable signal to control the discharge module 500 to quickly discharge the energy storage module 400, ensuring that the switch module 200 can be disconnected in time, effectively preventing arcing during hot-plugging.
[0038] When the photovoltaic interface is reinserted, the voltage slowly rises from zero, and a pre-charge current exists simultaneously. Therefore, the control module 600 will not generate a discharge enable signal, thus allowing the normal pre-charge process to proceed and avoiding accidental triggering of the discharge module during the pre-charge phase.
[0039] Figure 3 The circuit diagram of a hot-swappable discharge circuit provided by this utility model is shown. The input module 100 includes an input terminal CN1, an input protection element F1, a filter capacitor C3, a filter capacitor C4, a resistor R18, a resistor R19, and a coupling inductor L1.
[0040] The positive terminal of input terminal CN1 is connected to the first terminal of input protection element F1. The second terminal of input protection element F1 is connected to the first terminal of capacitor C3 and the first terminal of coupling inductor L1. The negative terminal of input terminal CN1 is connected to the second terminal of capacitor C3 and the fourth terminal of coupling inductor L1. The second terminal of coupling inductor L1 is connected to the first terminal of capacitor C4 and the input terminal of switch module 200 (i.e., Figure 3 The first terminal of the relay RLY1 (shown as the switch), the third terminal of the coupling inductor L1 and the second terminal of the capacitor C4 are connected to the first reference ground GND_PV1.
[0041] The input terminal CN1 serves as the access point for photovoltaic power and is typically designed as a dedicated connector to accommodate the plugging and unplugging operations of the photovoltaic system.
[0042] Switching module 200 includes relay RLY1, diode D3, switching transistor Q4, resistor R7, and resistor R11. The first terminal of relay RLY1 is connected to the output terminal of input module 100 (i.e.,...). Figure 3The second terminal of the coupling inductor L1 is connected to the second terminal of the relay RLY1 switch and the input terminal of the conversion module 700 (i.e., the second terminal of the coupling inductor L1 is connected to the input terminal of the conversion module 700). Figure 3 The drain of the switch Q1 is connected to the circuit. The first terminal of the coil of the relay RLY1 is connected to the cathode of the diode D3 and the second voltage source. The second terminal of the coil of the relay RLY1 is connected to the cathode of the diode D2 and the collector of the switch Q4. The base of the switch Q4 is connected to the first terminal of the resistor R7 and the first terminal of the resistor R11. The second terminal of the resistor R7 is connected to the photovoltaic enable signal PV_EN. The second terminal of the resistor R11 and the emitter of the switch Q4 are connected to the second reference ground GND_BAT.
[0043] The precharge module 300 includes a diode D1 and a thermistor RT1. The anode of diode D1 is connected to the output terminal of the input module 100 (i.e., Figure 3 The second terminal of the coupling inductor L1 is connected to the first terminal of the diode D1, and the second terminal of the thermistor RT1 is connected to the energy storage module 400 (i.e., Figure 3 The first terminal of the electrolytic capacitor EC2 shown is connected.
[0044] The energy storage module 400 includes an electrolytic capacitor EC2, the first terminal of the electrolytic capacitor EC2 and the output terminal of the precharge module 300 (i.e., Figure 3 The second terminal of the thermistor RT1 shown is connected, and the second terminal of the electrolytic capacitor EC2 is connected to the second reference ground GND_BAT.
[0045] The discharge module 500 includes a discharge resistor RW1, a switching transistor Q3, and a resistor R9. The first terminal of the discharge resistor RW1 and the energy storage module 400 (i.e., Figure 3 The first terminal of the electrolytic capacitor EC2 is connected to the first terminal of the discharge resistor RW1, and the drain of the switching transistor Q3 is connected to the second terminal of the discharge resistor RW1. The gate of the switching transistor Q3 is connected to the first terminal of the resistor R9, and the output terminal of the control module 600 is connected to the first terminal of the control module 600. Figure 4 The output terminal of logic gate U3B is connected as shown. The source of switch Q3 and the second terminal of resistor R9 are connected to the second reference ground GND_BAT.
[0046] The conversion module 700 includes switching transistor Q1, switching transistor Q2, inductor L2, resistors R1, R2, R3, R6, R8, R10, R11, R12, R13, capacitors C1, C2, C5, C6, electrolytic capacitor EC1, diode D4, and diode D2.
[0047] The drain of the switching transistor Q1 is connected to the first terminal of the capacitor C2 and the output terminal of the switching module 200 (i.e., Figure 3The second terminal of the relay RLY1 is connected to the second terminal of the capacitor C2, the second terminal of the capacitor C2 is connected to the first terminal of the resistor R2, the gate of the switch Q1 is connected to the first terminal of the resistor R1 and the first terminal of the resistor R3, the second terminal of the resistor R1 is connected to the controller to receive the first enable signal PV_H1; the source of the switch Q1 is connected to the second terminal of the resistor R3, the second terminal of the resistor R2 and the controller to receive the second enable signal PV1_S1.
[0048] The source of the switching transistor Q1 is also connected to the cathode of the diode D4, the first terminal of the capacitor C5, and the first terminal of the inductor L2. The second terminal of the capacitor C5 is connected to the first terminal of the resistor R10. The second terminal of the inductor L2 is connected to the anode of the diode D2, the drain of the switching transistor Q2, the first terminal of the resistor R6, and the first terminal of the capacitor C6. The cathode of the diode D2 is connected to the first terminal of the capacitor C1, the first terminal of the electrolytic capacitor EC1, and the subsequent equipment. The second terminal of the capacitor C1 is connected to the second terminal of the resistor R6. The second terminal of the capacitor C6 is connected to the first terminal of the resistor R13.
[0049] The gate of the switching transistor Q2 is connected to the first terminal of resistor R8 and the first terminal of resistor R12. The second terminal of resistor R8 is connected to the controller to receive the third enable signal PV_L2. The anode of diode D4, the second terminal of resistor R10, the second terminal of resistor R12, the source of switching transistor Q2, the second terminal of resistor R13, and the second terminal of electrolytic capacitor EC1 are connected to the second reference ground GND_BAT.
[0050] In this embodiment, when the control module 600 outputs a high-level discharge enable signal FD_EN, the switch Q3 is turned on, forming a discharge path from the electrolytic capacitor EC2 through the discharge resistor RW1 and the switch Q3 to the reference ground, quickly releasing the electrical energy in the electrolytic capacitor EC2. The discharge resistor RW1 is a power discharge resistor, capable of withstanding the energy consumption during the discharge process; its resistance value must be selected to balance discharge speed and heat control.
[0051] In this embodiment, the switching module 200 controls the connection between the input module 100 and the conversion module 700 via the relay RLY1. When the controller outputs a high-level photovoltaic enable signal PV_EN, the switching transistor Q4 is turned on, the coil of the relay RLY1 is energized, the contacts close, and the connection between the input module 100 and the conversion module 700 is established. Diode D3 is used to protect the switching transistor Q4, preventing the back electromotive force generated when the relay coil is de-energized from damaging the circuit.
[0052] In this embodiment, the pre-charge module 300 forms a pre-charge circuit path through diode D1 and thermistor RT1. After the input module 100 is connected, current flows through diode D1 and thermistor RT1 to slowly charge the electrolytic capacitor EC2. Thermistor RT1 is a PTC (positive temperature coefficient) thermistor, whose resistance increases with temperature. During initial charging, its resistance is low, allowing a suitable current to pass through. When the current is too large and causes the temperature to rise, its resistance increases, limiting the current and providing current limiting protection.
[0053] Electrolytic capacitor EC2 is used to store energy and smooth voltage fluctuations; its capacity selection should consider system power requirements and stability requirements. In hot-swapping scenarios, residual electrical energy in electrolytic capacitor EC2 is the main cause of arcing.
[0054] Figure 4 The circuit diagram of a control module provided by this utility model is shown, wherein the voltage detection unit 610 includes resistors R14, R15, R16, R18, R19, and R20, capacitors C7, C8, and C9, operational amplifier U1B, and operational amplifier U2B.
[0055] The non-inverting input of operational amplifier U1B is connected to the first terminal of capacitor C7, the first terminal of resistor R16, and the first terminal of resistor R18. The inverting input of operational amplifier U1B is connected to the first terminal of resistor R19, the first terminal of resistor R20, and the first terminal of capacitor C9. The output of operational amplifier U1B is connected to the second terminal of resistor R20, the second terminal of capacitor C9, and the inverting input of operational amplifier U2B.
[0056] The non-inverting input of operational amplifier U2B is connected to the first terminal of resistor R14 and the first terminal of resistor R15. The output of operational amplifier U2B is connected to the first input of logic unit 630 (i.e., Figure 4 As shown, the first input terminal of logic gate U3B is connected, the second terminal of resistor R18 and the first terminal of capacitor C8 are connected, and the output terminal of input module 100 (i.e., Figure 3 The second end of the coupling inductor L1 is connected to the first reference ground GND_PV1, the second end of resistor R19 and capacitor C8 are connected to the first reference ground GND_PV1, the second end of resistor R14 is connected to the first voltage source 3.3V, and the second ends of capacitor C7, resistor R16 and resistor R15 are connected to the second reference ground GND_BAT.
[0057] In this embodiment, the voltage detection unit 610 forms a comparator circuit for detecting changes in the PV input voltage. Operational amplifier U1B is configured as an inverting buffer amplifier, comparing the input voltage with a reference voltage at its non-inverting input via resistor R18. Operational amplifier U2B is configured as another comparator stage, comparing the output of operational amplifier U1B with a reference voltage set via resistors R14 and R15, and the output is connected to logic unit 630. Capacitors C7, C8, and C9 are used for filtering to eliminate high-frequency interference and improve circuit stability.
[0058] When the PV voltage is normal, the voltage after voltage division through resistors R18 and R19 is higher than the reference voltage at the non-inverting input of operational amplifier U1B, causing operational amplifier U1B to output a high level. This makes the voltage at the inverting input of operational amplifier U2B higher than that at the non-inverting input, resulting in operational amplifier U2B outputting a low level. When the PV voltage is disconnected, the input voltage drops rapidly, operational amplifier U1B outputs a low level, and the voltage at the inverting input of operational amplifier U2B falls below that at the non-inverting input, causing operational amplifier U2B to output a high level and send a voltage detection signal to logic unit 630.
[0059] The current detection unit 620 includes resistors R21, R22, R24, R25, R26, R27, R28, and R29, capacitors C10, C11, and C12, operational amplifier U1C, and operational amplifier U2C.
[0060] The non-inverting input of operational amplifier U1C is connected to the first terminal of capacitor C1, the first terminal of resistor R24, and the first terminal of resistor R25. The inverting input of operational amplifier U1C is connected to the first terminal of resistor R26, the first terminal of resistor R27, and the first terminal of capacitor C12. The output of operational amplifier U1C is connected to the second terminal of resistor R27, the second terminal of capacitor C12, and the inverting input of operational amplifier U2C.
[0061] The non-inverting input of operational amplifier U2C is connected to the first terminal of resistor R21 and the first terminal of resistor R22. The output of operational amplifier U2C is connected to the second input of logic unit 630 (i.e., Figure 4 The second input terminal of the logic gate U3B is connected as shown, and the second terminal of the resistor R21 is connected to the first voltage source 3.3V.
[0062] The second terminals of resistor R26, capacitor C11, resistor R28, and resistor R29 are connected to the first reference ground GND_PV1. The second terminals of resistor R22, resistor R24, resistor R25, resistor R28, resistor R29, capacitor C10, and capacitor C11 are connected to the second reference ground GND_BAT.
[0063] In this embodiment, the current detection unit 620 constitutes a comparator circuit for detecting the input current, and its structure is similar to that of the voltage detection unit. Operational amplifier U1C is configured to acquire and amplify the current signal and convert it into a voltage signal for processing. Operational amplifier U2C is configured as a comparator, comparing the output of operational amplifier U1C with a reference voltage set by resistors R21 and R22, and the output is connected to logic unit 630.
[0064] When the PV is charging normally, the detected current signal is amplified and exceeds the set threshold. The voltage at the inverting input of operational amplifier U2C is higher than that at the non-inverting input, and operational amplifier U2C outputs a low level. When the PV is disconnected, the input current decreases rapidly, the signal acquired by operational amplifier U1C decreases, causing the voltage at the inverting input of operational amplifier U2C to fall below that at the non-inverting input. Operational amplifier U2C outputs a high level and sends a current detection signal to logic unit 630.
[0065] Logic unit 630 includes logic gate U3B, resistor R17, and resistor R23. The first input terminal of logic gate U3B, the first terminal of resistor R17, and the output terminal of voltage detection unit 610 are connected (i.e.,...). Figure 4 The output terminal of the operational amplifier U2B shown, the second input terminal of the logic gate U3B, the first terminal of the resistor R23, and the output terminal of the current detection unit 620 (i.e., Figure 4 The output terminal of the operational amplifier U2C shown is connected to the output terminal of the logic gate U3B and the controlled terminal of the discharge module 500 (i.e., Figure 3 The gate of the switch Q3 shown is connected, and the second end of resistor R17 and the second end of resistor R23 are connected to the first voltage source 3.3V.
[0066] In this embodiment, logic gate U3B receives signals from voltage detection unit 610 and current detection unit 620. When both inputs are high simultaneously, it outputs a high-level discharge enable signal FD_EN to discharge module 500. Resistors R17 and R23 act as pull-up resistors to ensure the stability of the signal lines and prevent uncertainties caused by floating signal lines.
[0067] The voltage detection unit 610 and the current detection unit 620 work together to ensure the system's accurate identification of the PV disconnection state through dual condition judgments: when the input voltage PV2 is lower than the preset voltage threshold, the voltage detection unit 610 outputs a high-level voltage detection signal; when the input current is lower than the preset current threshold, the current detection unit 620 outputs a high-level current detection signal.
[0068] Only when both conditions are met simultaneously will logic unit 630 output a high-level discharge enable signal FD_EN, initiating discharge module 500 for rapid discharge. This dual-condition judgment mechanism significantly improves system reliability and avoids false triggering in the following situations: voltage fluctuations during normal charging; temporary drops in input voltage caused by changes in light intensity; and the pre-charging process during system startup.
[0069] The specific working principle is as follows: When PV is input normally, the electrolytic capacitor EC2 is first pre-charged through the pre-charge module 300 (diode D1 and thermistor RT1). When the voltage across the electrolytic capacitor EC2 reaches a certain value, the controller outputs a high-level PV_EN signal, the switch Q4 is turned on, the relay RLY1 is closed, and the system enters the normal charging state. At this time, the discharge enable signal FD_EN is low, the switch Q3 does not work, and the discharge module 500 does not start.
[0070] When PV is disconnected, the input voltage drops rapidly. The voltage detection unit 610 detects that the input voltage PV2 is lower than the preset voltage threshold and outputs a voltage detection signal. Simultaneously, the current detection unit 620 detects that the input current is close to zero and lower than the preset current threshold, and outputs a current detection signal. After receiving the voltage and current detection signals, the logic unit 630 outputs a discharge enable signal FD_EN, turning on the switch Q3 and forming a discharge circuit of electrolytic capacitor EC2 / discharge resistor RW1 / switch Q3 / second reference ground GND_BAT, rapidly releasing the residual energy in electrolytic capacitor EC2 in a discharge time of only a few milliseconds. Subsequently, the controller detects that the input voltage PV2 is low and immediately disconnects the relay RLY1.
[0071] When the PV is reinserted, the input voltage slowly rises from zero. At this time, the precharge module 300 works. Simultaneously, due to the presence of precharge current, the current detection unit 620 outputs a low level, and the logic unit 630 outputs a low-level FD_EN signal. The switching transistor Q3 is not turned on, the discharge module 500 does not work, and the precharge process is completed normally, avoiding arcing.
[0072] Unlike existing technologies, this utility model embodiment detects the input voltage through a control module. When the input voltage is detected to be disconnected, a discharge enable signal is output to control the discharge module to quickly discharge the energy storage module, thereby rapidly disconnecting the switching module and avoiding arcing during hot-plugging, effectively preventing oxidation of the input port contacts.
[0073] It should be noted that while the preferred embodiments of this utility model are provided in the specification and accompanying drawings, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are not intended to impose additional limitations on the content of this utility model; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Furthermore, the above-described technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of this utility model specification. Moreover, those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A hot plug discharge circuit, characterized by, The application relates to a photovoltaic power supply input module, which comprises an input module configured to receive a photovoltaic power supply input; a conversion module configured to convert an input voltage of the input module; a switch module connected between the input module and the conversion module and configured to receive the input voltage and output the input voltage when turned on; an energy storage module connected with the switch module and configured to store electric energy; a pre-charging module connected between the input module and the conversion module and configured to pre-charge the energy storage module when the input voltage is received; a control module connected with the switch module and configured to generate a discharge enable signal according to the input voltage and an input current of the input module; and a discharge module connected with the energy storage module and the control module and configured to discharge the energy storage module to turn off the switch module in response to the discharge enable signal. The control module comprises a voltage detection unit connected with the input module and configured to generate a voltage detection signal when the input voltage is lower than a preset voltage threshold; a current detection unit connected with the input module and configured to generate a current detection signal when an input current of the input module is less than a preset current threshold; and a logic unit connected with the voltage detection unit, the current detection unit and the discharge module and configured to generate the discharge enable signal in response to the voltage detection signal and the current detection signal. The voltage detection unit comprises resistors R14, R15, R16, R18, R19, R20, capacitors C7, C8, C9, an operational amplifier U1B and an operational amplifier U2B. The non-inverting input terminal of the operational amplifier U1B is connected with the first terminal of the capacitor C7, the first terminal of the resistor R16 and the first terminal of the resistor R18, the inverting input terminal of the operational amplifier U1B is connected with the first terminal of the resistor R19, the first terminal of the resistor R20 and the first terminal of the capacitor C9, and the output terminal of the operational amplifier U1B is connected with the second terminal of the resistor R20, the second terminal of the capacitor C9 and the inverting input terminal of the operational amplifier U2B. The non-inverting input terminal of the operational amplifier U2B is connected with the first terminal of the resistor R14 and the first terminal of the resistor R15, the output terminal of the operational amplifier U2B is connected with the first input terminal of the logic unit, the second terminal of the resistor R18 is connected with the first terminal of the capacitor C8 and the output terminal of the input module, the second terminal of the resistor R19 is connected with the second terminal of the capacitor C8 and a first reference ground, the second terminal of the resistor R14 is connected with a first voltage source, and the second terminal of the capacitor C7, the second terminal of the resistor R16 and the second terminal of the resistor R15 are connected with a second reference ground. 2. The circuit of claim 1, wherein, 3. The circuit of claim 2, wherein, 4. The circuit of claim 2, wherein, The current detection unit comprises resistors R21, R22, R24, R25, R26, R27, R28, R29, capacitors C10, C11, C12, operational amplifier U1C and operational amplifier U2C, The non-inverting input terminal of the operational amplifier U1C is connected with the first terminal of the capacitor C1, the first terminal of the resistor R24 and the first terminal of the resistor R25, the inverting input terminal of the operational amplifier U1C is connected with the first terminal of the resistor R26, the first terminal of the resistor R27 and the first terminal of the capacitor C12, and the output terminal of the operational amplifier U1C is connected with the second terminal of the resistor R27, the second terminal of the capacitor C12 and the inverting input terminal of the operational amplifier U2C; The non-inverting input terminal of the operational amplifier U2C is connected with the first terminal of the resistor R21 and the first terminal of the resistor R22, the output terminal of the operational amplifier U2C is connected with the second input terminal of the logic unit, and the second terminal of the resistor R21 is connected with a first voltage source, The second terminal of the resistor R26, the second terminal of the capacitor C11, the second terminal of the resistor R28 and the second terminal of the resistor R29 are connected with a first reference ground, and the second terminal of the resistor R22, the second terminal of the resistor R24, the second terminal of the resistor R25, the first terminal of the resistor R28, the first terminal of the resistor R29, the second terminal of the capacitor C10 and the first terminal of the capacitor C11 are connected with a second reference ground.
5. The circuit of claim 2, wherein, The logic unit comprises an AND logic gate U3B, a resistor R17 and a resistor R23, The first input terminal of the AND logic gate U3B is connected with the first terminal of the resistor R17 and the output terminal of the voltage detection unit, the second input terminal of the AND logic gate U3B is connected with the first terminal of the resistor R23 and the output terminal of the current detection unit, the output terminal of the AND logic gate U3B is connected with the controlled terminal of the discharge module, and the second terminal of the resistor R17 and the second terminal of the resistor R23 are connected with a first voltage source.
6. The circuit of claim 1 or 2, wherein The discharge module comprises a discharge resistor RW1, a switching tube Q3 and a resistor R9, The first terminal of the discharge resistor RW1 is connected with the energy storage module, the second terminal of the discharge resistor RW1 is connected with the drain of the switching tube Q3, the gate of the switching tube Q3 is connected with the first terminal of the resistor R9 and the output terminal of the control module, and the source of the switching tube Q3 is connected with the second terminal of the resistor R9 and a second reference ground.
7. The circuit of claim 1 or 2, wherein The switching module comprises a relay RLY1, a diode D3, a switching tube Q4, a resistor R7 and a resistor R11, The first end of the switch of the relay RLY1 is connected with the output end of the input module, the second end of the switch of the relay RLY1 is connected with the input end of the conversion module, the first end of the coil of the relay RLY1 is connected with the cathode of the diode D3 and the second voltage source, the second end of the coil of the relay RLY1 is connected with the cathode of the diode D2 and the collector of the switch tube Q4, the base of the switch tube Q4 is connected with the first end of the resistor R7 and the first end of the resistor R11, the second end of the resistor R7 is connected with the photovoltaic enable signal, the second end of the resistor R11 is connected with the emitter of the switch tube Q4 and the second reference ground.
8. The circuit of claim 1 or 2, wherein, The pre-charge module comprises a diode D1 and a thermistor RT1, The anode of the diode D1 is connected with the output end of the input module, the cathode of the diode D1 is connected with the first end of the thermistor RT1, and the second end of the thermistor RT1 is connected with the energy storage module.
9. The circuit of claim 1 or 2, wherein, The energy storage module comprises an electrolytic capacitor EC2, the first end of the electrolytic capacitor EC2 is connected with the output end of the pre-charge module, and the second end of the electrolytic capacitor EC2 is connected with the second reference ground.
10. An energy storage system characterized by, Comprise: The hot plug discharging circuit according to any one of claims 1-9.