Energy storage charging pile LLC overshoot protection circuit

By designing voltage sampling and detection circuits in the charging pile, the problems of component damage and voltage ring failure during soft start-up are solved, and the safety and stability of the charging pile are improved.

CN222169310UActive Publication Date: 2024-12-13SICHUAN SUNRAIN SIGN & DISPLAY SYST
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Patent Information

Application Number
CN202323504422.6
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2023-12-21
Publication Date
2024-12-13
Estimated Expiration
2033-12-21

AI Technical Summary

Technical Problem

During the soft start process of charging piles, too fast or too slow soft start will cause components to be damaged, and the output voltage may exceed the set value, resulting in the voltage ring failure and cannot be controlled by the MCU.

Method used

A LLC overshoot protection circuit of energy storage charging pile is designed, including a voltage sampling detection circuit and a resonant cavity discharge circuit. Through the combination of the rectifier bridge and the control circuit, the output voltage is monitored and adjusted to prevent overcharging, ensuring the safety of the charging pile and Stable operation.

Benefits of technology

It effectively prevents components from being damaged, improves the safety and reliability of the charging pile, prevents voltage ring failure caused by overshooting the output voltage, and ensures the safe and stable operation of the charging equipment.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses an LLC overshoot protection circuit of an energy storage charging pile. The LLC overshoot protection circuit comprises a control circuit, an input circuit, a voltage sampling detection circuit, a resonant cavity discharging circuit and a rectifier bridge. Wherein the voltage sampling detection circuit and the resonant cavity discharge circuit form a protection circuit; the input circuit is connected with one end of the rectifier bridge, the other end of the rectifier bridge is respectively connected with the voltage sampling detection circuit and the resonant cavity discharge circuit, and the resonant cavity discharge circuit is respectively connected with the control circuit and the voltage sampling detection circuit. According to the utility model, the voltage sampling detection circuit, the resonant cavity discharge circuit and the rectifier bridge are arranged to protect the charging pile from being damaged by overcharge, so as to ensure the safe and stable operation of the charging pile. The voltage sampling detection circuit and the resonant cavity discharging circuit form a protection circuit which is used for monitoring and adjusting the voltage of the charging pile so as to prevent overcharging, the safety and reliability of the charging pile can be improved, and therefore the charging pile and charging equipment are protected against damage.
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Description

Technical Field

[0001] The utility model belongs to the technical field of charging pile protection, in particular to an LLC overcharge protection circuit for an energy storage charging pile. Background Art

[0002] During the soft start process of the charging pile and energy storage high-power LLC full-bridge topology, the frequency of the LLC resonant cavity is adjusted from large to small (high frequency means low output voltage, low frequency means high output voltage). If the soft start is too fast, the large surge will have a large impact on the current of the components and even damage the components. If the soft start is too slow, the output voltage may exceed the set value of the voltage loop, the output voltage may overshoot, and the voltage loop may fail and the output voltage cannot be adjusted and controlled by the MCU. Utility Model Content

[0003] The purpose of the utility model is to provide an LLC overcharge protection circuit for an energy storage charging pile, so as to solve the problem in the prior art proposed in the background technology that the charging pile is easily damaged by the soft start being too fast or too slow during the soft start process.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] An LLC overcharge protection circuit for an energy storage charging pile includes a control circuit, an input circuit, a voltage sampling detection circuit, a resonant cavity discharge circuit, and a rectifier bridge; wherein the voltage sampling detection circuit and the resonant cavity discharge circuit constitute a protection circuit;

[0006] The input circuit is connected to one end of the rectifier bridge, the other end of the rectifier bridge is respectively connected to the voltage sampling detection circuit and the resonant cavity discharge circuit, and the resonant cavity discharge circuit is respectively connected to the control circuit and the voltage sampling detection circuit;

[0007] The voltage sampling detection circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a capacitor C1; the resonant cavity discharge circuit includes a resistor R6, a resistor R7, a resistor R8 and a MOS tube Q5; one end of the resistor R1 is respectively connected to one end of the resistor R6, pin No. 3 of the rectifier bridge and the positive electrode of the output end; the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4, one end of the capacitor C1 and the control circuit, and the other end of the resistor R4 is respectively connected to the other end of the capacitor C1, pin No. 4 of the rectifier bridge, one end of the MOS tube Q5 and the negative electrode of the output end;

[0008] The resistor R6, the resistor R7, the resistor R8 and the MOS transistor Q5 are connected in sequence, and the MOS transistor Q5 is also connected to the control circuit.

[0009] According to the above technical solution, the protection circuit also includes a capacitor C0, one end of which is respectively connected to the resistor R1, the resistor R6, the pin 3 of the rectifier bridge and the positive electrode of the output end, and the other end of the capacitor C0 is respectively connected to the capacitor C1, the resistor R4, the pin 4 of the rectifier bridge, one end of the MOS tube Q5 and the negative electrode of the output end.

[0010] According to the above technical solution, capacitor C0, capacitor C1, resistor R4, MOS tube Q5 and pin 4 of the rectifier bridge are all grounded.

[0011] According to the above technical solution, the input circuit includes MOS transistor Q1, MOS transistor Q2, MOS transistor Q3, MOS transistor Q4, inductor Lr, capacitor Cr and transformer T1;

[0012] One end of the MOS transistor Q1 is connected to the positive electrode of the input terminal and one end of the MOS transistor Q3; the other end of the MOS transistor Q1 is connected to one end of the MOS transistor Q2 and one end of the inductor Lr; the other end of the MOS transistor Q2 is connected to the negative electrode of the input terminal and one end of the MOS transistor Q4;

[0013] The other end of the MOS tube Q3 is connected to the No. 2 pin of the transformer T1 and the other end of the MOS tube Q4 respectively; the other end of the inductor Lr is connected to one end of the capacitor Cr, and the other end of the capacitor Cr is connected to the No. 1 pin of the transformer T1;

[0014] Pin 3 of transformer T1 is connected to pin 1 of the rectifier bridge, and pin 5 of transformer T1 is connected to pin 2 of the rectifier bridge;

[0015] The MOS tube Q2 and the MOS tube Q4 are both grounded.

[0016] According to the above technical solution, the control circuit includes a chip U1, a resistor R5, a resistor R9 and a driving chip U2;

[0017] Pin No. 1 of chip U1 is connected to one end of resistor R9, the other end of resistor R9 is connected to one end of driver chip U2, and the other end of driver chip U2 is connected to MOS tube Q5; Pin No. 2 of chip U1 is connected to one end of resistor R5, and the other end of resistor R5 is connected to resistor R3, resistor R4 and capacitor C1 respectively.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] In the utility model, a voltage sampling detection circuit, a resonant cavity discharge circuit and a rectifier bridge are provided to protect the charging pile from the harm of overcharging, so as to ensure the safe and stable operation of the charging pile. The voltage sampling detection circuit and the resonant cavity discharge circuit constitute a protection circuit, which is used to monitor and adjust the voltage of the charging pile to prevent overcharging, which helps to improve the safety and reliability of the charging pile, thereby protecting the charging pile and the charging equipment from damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] Embodiment 1

[0023] like Figure 1 As shown, an LLC overcharge protection circuit for an energy storage charging pile includes a control circuit, an input circuit, a voltage sampling detection circuit, a resonant cavity discharge circuit, and a rectifier bridge; wherein the voltage sampling detection circuit and the resonant cavity discharge circuit constitute a protection circuit;

[0024] The input circuit is connected to one end of the rectifier bridge, the other end of the rectifier bridge is respectively connected to the voltage sampling detection circuit and the resonant cavity discharge circuit, and the resonant cavity discharge circuit is respectively connected to the control circuit and the voltage sampling detection circuit;

[0025] The voltage sampling detection circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a capacitor C1; the resonant cavity discharge circuit includes a resistor R6, a resistor R7, a resistor R8 and a MOS tube Q5; one end of the resistor R1 is respectively connected to one end of the resistor R6, pin No. 3 of the rectifier bridge and the positive electrode of the output end; the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4, one end of the capacitor C1 and the control circuit, and the other end of the resistor R4 is respectively connected to the other end of the capacitor C1, pin No. 4 of the rectifier bridge, one end of the MOS tube Q5 and the negative electrode of the output end;

[0026] The resistor R6, the resistor R7, the resistor R8 and the MOS transistor Q5 are connected in sequence, and the MOS transistor Q5 is also connected to the control circuit.

[0027] In the utility model, a voltage sampling detection circuit, a resonant cavity discharge circuit and a rectifier bridge are provided to protect the charging pile from the harm of overcharging, so as to ensure the safe and stable operation of the charging pile. The voltage sampling detection circuit and the resonant cavity discharge circuit constitute a protection circuit, which is used to monitor and adjust the voltage of the charging pile to prevent overcharging, which helps to improve the safety and reliability of the charging pile, thereby protecting the charging pile and the charging equipment from damage.

[0028] Embodiment 2

[0029] This embodiment is a further refinement of the first embodiment.

[0030] like Figure 1 As shown, the protection circuit also includes a capacitor C0, one end of which is respectively connected to the resistor R1, the resistor R6, the pin 3 of the rectifier bridge and the positive electrode of the output end, and the other end of the capacitor C0 is respectively connected to the capacitor C1, the resistor R4, the pin 4 of the rectifier bridge, one end of the MOS tube Q5 and the negative electrode of the output end.

[0031] Capacitor C0, capacitor C1, resistor R4, MOS tube Q5 and pin 4 of the rectifier bridge are all grounded.

[0032] like Figure 1 As shown, the input circuit includes MOS transistor Q1, MOS transistor Q2, MOS transistor Q3, MOS transistor Q4, inductor Lr, capacitor Cr and transformer T1;

[0033] One end of the MOS transistor Q1 is connected to the positive electrode of the input terminal and one end of the MOS transistor Q3; the other end of the MOS transistor Q1 is connected to one end of the MOS transistor Q2 and one end of the inductor Lr; the other end of the MOS transistor Q2 is connected to the negative electrode of the input terminal and one end of the MOS transistor Q4;

[0034] The other end of the MOS tube Q3 is connected to the No. 2 pin of the transformer T1 and the other end of the MOS tube Q4 respectively; the other end of the inductor Lr is connected to one end of the capacitor Cr, and the other end of the capacitor Cr is connected to the No. 1 pin of the transformer T1;

[0035] Pin 3 of transformer T1 is connected to pin 1 of the rectifier bridge, and pin 5 of transformer T1 is connected to pin 2 of the rectifier bridge;

[0036] The MOS tube Q2 and the MOS tube Q4 are both grounded.

[0037] like Figure 1 As shown, the control circuit includes a chip U1, a resistor R5, a resistor R9 and a driving chip U2;

[0038] Pin No. 1 of chip U1 is connected to one end of resistor R9, the other end of resistor R9 is connected to one end of driver chip U2, and the other end of driver chip U2 is connected to MOS tube Q5; Pin No. 2 of chip U1 is connected to one end of resistor R5, and the other end of resistor R5 is connected to resistor R3, resistor R4 and capacitor C1 respectively.

[0039] The technical solution in the utility model is mainly aimed at the output voltage overshoot and the failure of the voltage loop during the soft start process of the high-power LLC full-bridge topology structure.

[0040] Resistors R1, R2, R3, R4 and capacitor C1 form a voltage sampling detection circuit, and the output voltage sampling value is sent to pin 2 (ADC1) of chip U1 (chip U1 is MCU) for processing;

[0041] Resistors R6, R7, R8 and MOS tube Q5 form a resonant cavity discharge circuit. Resistors R6, R7 and R8 are selected from high-power cement resistors or multiple resistors connected in parallel and then in series. The resonant cavity discharge power meets the requirement of being greater than 20W, and the resistance string withstand voltage value is greater than 1KV.

[0042] LLC full-bridge topology startup process: First, pin 1 (I / O1) of chip U1 (MCU microcontroller) outputs a high level to control the MOS tube Q5 to turn on, and the resonant cavity discharge circuit works; LLC full-bridge topology soft start is turned on, and pin 1 (I / O1) of chip U1 (MCU microcontroller) outputs an output time of 1.5S, and then the high level changes to a low level. The discharge time should not be too long. If the discharge time is too long, the heat of the resistor requires additional heat dissipation costs and is not energy-saving.

[0043] If the voltage sampling circuit detects that the output voltage is higher than the set reference voltage, the LLC full-bridge topology will reset and start the soft start until the output voltage drops to the set reference voltage and the resonant cavity discharge loop is closed; finally, the energy of the soft start is exhausted by the resistors R6, R7, R8 and MOS tube Q5. At this time, the amplitude of the output voltage is suppressed and the voltage loop will not fail due to loop voltage overshoot.

[0044] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0045] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An LLC overcharge protection circuit for energy storage charging piles, Features: It includes a control circuit, an input circuit, a voltage sampling detection circuit, a resonant cavity discharge circuit and a rectifier bridge; wherein the voltage sampling detection circuit and the resonant cavity discharge circuit constitute a protection circuit; The input circuit is connected to one end of the rectifier bridge, the other end of the rectifier bridge is respectively connected to the voltage sampling detection circuit and the resonant cavity discharge circuit, and the resonant cavity discharge circuit is respectively connected to the control circuit and the voltage sampling detection circuit; The voltage sampling detection circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a capacitor C1; the resonant cavity discharge circuit includes a resistor R6, a resistor R7, a resistor R8 and a MOS tube Q5; one end of the resistor R1 is respectively connected to one end of the resistor R6, pin No. 3 of the rectifier bridge and the positive electrode of the output end; the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4, one end of the capacitor C1 and the control circuit, and the other end of the resistor R4 is respectively connected to the other end of the capacitor C1, pin No. 4 of the rectifier bridge, one end of the MOS tube Q5 and the negative electrode of the output end; The resistor R6, the resistor R7, the resistor R8 and the MOS transistor Q5 are connected in sequence, and the MOS transistor Q5 is also connected to the control circuit.

2. An LLC overcharge protection circuit for energy storage charging pile according to claim 1, Features: The protection circuit also includes a capacitor C0, one end of which is respectively connected to the resistor R1, the resistor R6, the pin 3 of the rectifier bridge and the positive electrode of the output terminal, and the other end of the capacitor C0 is respectively connected to the capacitor C1, the resistor R4, the pin 4 of the rectifier bridge, one end of the MOS tube Q5 and the negative electrode of the output terminal.

3. An LLC overcharge protection circuit for energy storage charging pile according to claim 2, Features: Capacitor C0, capacitor C1, resistor R4, MOS tube Q5 and pin 4 of the rectifier bridge are all grounded.

4. An LLC overcharge protection circuit for energy storage charging pile according to claim 1, Features: The input circuit includes MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4, inductor Lr, capacitor Cr and transformer T1; One end of the MOS transistor Q1 is connected to the positive electrode of the input terminal and one end of the MOS transistor Q3; the other end of the MOS transistor Q1 is connected to one end of the MOS transistor Q2 and one end of the inductor Lr; the other end of the MOS transistor Q2 is connected to the negative electrode of the input terminal and one end of the MOS transistor Q4; The other end of the MOS tube Q3 is connected to the No. 2 pin of the transformer T1 and the other end of the MOS tube Q4 respectively; the other end of the inductor Lr is connected to one end of the capacitor Cr, and the other end of the capacitor Cr is connected to the No. 1 pin of the transformer T1; Pin 3 of transformer T1 is connected to pin 1 of the rectifier bridge, and pin 5 of transformer T1 is connected to pin 2 of the rectifier bridge; The MOS tube Q2 and the MOS tube Q4 are both grounded.

5. An LLC overcharge protection circuit for energy storage charging pile according to claim 1, Features: The control circuit includes a chip U1, a resistor R5, a resistor R9 and a driving chip U2; Pin No. 1 of chip U1 is connected to one end of resistor R9, the other end of resistor R9 is connected to one end of driver chip U2, and the other end of driver chip U2 is connected to MOS tube Q5; Pin No. 2 of chip U1 is connected to one end of resistor R5, and the other end of resistor R5 is connected to resistor R3, resistor R4 and capacitor C1 respectively.