Anti-surge circuit and energy storage system

Abstract

The utility model relates to an anti-surge circuit and an energy storage system. The anti-surge circuit comprises an energy storage starting unit, a main circuit switch unit, a surge switch unit, a primary anti-surge unit and a secondary anti-surge unit. Wherein the energy storage starting unit is used for controlling the conduction of the main circuit switch unit when an input power supply is connected, so as to connect a path between the input power supply and a load through the main circuit switch unit. In the process of connecting the path through the main circuit switch unit, if the input voltage of the input power supply is between a first voltage value and a second voltage value, the first-stage anti-surge unit is controlled to be switched on through the first surge voltage at the first connecting part, so that the first surge voltage is absorbed through the first-stage anti-surge unit; the surge switch unit is controlled to be switched on through the first surge voltage, so that the main circuit switch unit is switched off; and if the input voltage is greater than the second voltage value, a second surge voltage at the first connection part is absorbed through the second-stage anti-surge unit. By adopting the anti-surge circuit, the safety can be improved.

Description

Technical Field

[0001] This application relates to the field of power technology, and in particular to a surge-resistant circuit and energy storage system. Background Technology

[0002] Surge phenomena in the power sector are caused by a variety of complex factors, including atmospheric overvoltages caused by lightning strikes, short circuits due to power equipment malfunctions, and grounding faults. Therefore, circuits are frequently affected by surges during practical use. Surges cause instantaneous large voltage or current fluctuations, which can lead not only to circuit failures but also potential safety accidents. Thus, providing a surge-resistant circuit is a key technical problem in this field. Utility Model Content

[0003] Therefore, it is necessary to provide a surge protection circuit and energy storage system that can improve safety in response to the above-mentioned technical problems.

[0004] In a first aspect, this application provides a surge protection circuit, comprising:

[0005] The energy storage starting unit is connected to the input power supply;

[0006] The main circuit switching unit has its input terminal connected to the energy storage starting unit and its output terminal connected to the load. When the input power is connected, the energy storage starting unit is used to control the main circuit switching unit to conduct, so as to connect the path between the input power and the load through the main circuit switching unit.

[0007] The surge switch unit is connected to the main circuit switch unit, the input power supply, and the first connection point; the first connection point is the connection point between the input power supply and the input terminal of the main circuit switch unit.

[0008] The primary surge protection unit and the secondary surge protection unit are connected in parallel at the first connection point and the output terminal of the main circuit switching unit. The primary surge protection unit is also connected to the input power supply.

[0009] During the process of connecting the circuit through the main circuit switching unit, if the input voltage of the input power supply is between the first voltage value and the second voltage value, the first surge voltage at the first connection point controls the first-level surge protection unit to conduct, so as to absorb the first surge voltage through the first-level surge protection unit, and control the surge switch unit to conduct through the first surge voltage to make the main circuit switching unit disconnect; if the input voltage is greater than the second voltage value, the second surge voltage at the first connection point is absorbed through the second-level surge protection unit.

[0010] In one embodiment, the surge switch unit includes a first transistor; the collector of the first transistor is connected to the main circuit switch unit and the input power supply, the base of the first transistor is connected to a first connection point, and the emitter of the first transistor is grounded.

[0011] In one embodiment, the main circuit switching unit includes a second transistor; the gate of the second transistor is connected to the collector of the first transistor, the source of the second transistor is connected to the base of the first transistor, and the drain of the second transistor is connected to the load.

[0012] In one embodiment, the primary surge protection unit includes a first switching subunit and a surge absorption element; the first switching subunit is connected to the surge absorption element and a first connection point respectively.

[0013] When the input voltage is between the first voltage value and the second voltage value, the first switch subunit is turned on by the first surge voltage at the first connection so as to absorb the first surge voltage through the surge absorption element.

[0014] In one embodiment, the first switching subunit includes a third transistor and a first Zener diode; the gate and source of the third transistor are both connected to the anode of the first Zener diode, the drain of the third transistor is connected to a surge absorption element, the source of the third transistor is also grounded, and the cathode of the first Zener diode is connected to a first connection point.

[0015] In one embodiment, the energy storage start-up unit includes a charging subunit and a second switching subunit; the charging subunit and the second switching subunit are connected in parallel to the two ends of the input power supply, and the main circuit switching unit is connected to the two ends of the charging subunit respectively;

[0016] The input power supply is used to charge the charging sub-unit. When the voltage across the charging sub-unit is greater than the preset charging voltage, the charging sub-unit controls the main circuit switching unit to turn on.

[0017] In one embodiment, the charging subunit includes an energy storage element, and the second switching subunit includes a second Zener diode;

[0018] The two ends of the energy storage element are connected to the input power supply, the positive and negative terminals of the second Zener diode are connected to the negative and positive terminals of the input power supply respectively, and the main circuit switching unit is connected to the two ends of the energy storage element respectively.

[0019] In one embodiment, the surge protection circuit further includes at least one of the following:

[0020] The first resistor is connected to the input power supply and the negative terminal of the second Zener diode.

[0021] The second resistor is connected to the positive and negative terminals of the second Zener diode, respectively.

[0022] In one embodiment, if the input voltage of the input power supply is greater than the second voltage value, the secondary surge protection unit is controlled to melt by the input voltage.

[0023] Secondly, this application also provides an energy storage system that includes the surge protection circuit described above.

[0024] The surge protection circuit and energy storage system described above include an energy storage start-up unit, a main circuit switch unit, a surge switch unit, a primary surge protection unit, and a secondary surge protection unit. The energy storage start-up unit is connected to the input power supply; the input terminal of the main circuit switch unit is connected to the energy storage start-up unit, and the output terminal of the main circuit switch unit is connected to the load; the surge switch unit is connected to both the main circuit switch unit and the input power supply; the primary and secondary surge protection units are connected in parallel at the first connection point and the output terminal of the main circuit switch unit; the primary surge protection unit is also connected to the input power supply; the first connection point is the connection between the surge switch unit and the main circuit switch unit.

[0025] Furthermore, the energy storage starting unit is used to control the main circuit switching unit to conduct when the input power is connected, so as to connect the path between the input power and the load through the main circuit switching unit. During the process of connecting the path between the input power and the load through the main circuit switching unit, if the input voltage of the input power is between a first voltage value and a second voltage value, the first surge voltage at the first connection point can control the conduction of the first-stage surge protection unit to absorb the first surge voltage, and the surge switch unit can be turned on to disconnect the main circuit switching unit. If the input voltage is greater than the second voltage value, the second surge voltage at the first connection point can be absorbed by the second-stage surge protection unit. Therefore, on the one hand, the path between the input power 101 and the load 102 can be disconnected in time through the main circuit switching unit when a surge occurs, improving safety. On the other hand, when the surge is small, the first-stage surge protection unit can absorb the first surge voltage, and when the surge is large, the second-stage surge protection unit can absorb the second surge voltage. Thus, the safety of the surge protection circuit can be further improved through two levels of protection. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a surge protection circuit in one embodiment;

[0027] Figure 2 This is a schematic diagram of yet another surge protection circuit in one embodiment;

[0028] Figure 3 This is a schematic diagram of a primary surge protection unit in one embodiment;

[0029] Figure 4 This is a schematic diagram of an energy storage start-up unit in one embodiment;

[0030] Figure 5 This is a schematic diagram of an energy storage system in one embodiment.

[0031] Explanation of reference numerals in the attached figures:

[0032] 101-Input power supply, 102-Load, 200-Surge protection circuit, 201-Energy storage start-up unit, 2011-Charging sub-unit, 2012-Second switching sub-unit, 202-Main circuit switching unit, 203-Surge switching unit, 204-First-level surge protection unit, 2041-Surge absorption element, 2042-First switching sub-unit, 205-Second-level surge protection unit, 206-Filtering unit, 500-Energy storage system. Detailed Implementation

[0033] The serial numbers assigned to components in this document, such as "first" and "second," are used solely to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used solely for the convenience of describing this application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0034] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0036] Figure 1 This is a schematic diagram of a surge protection circuit in one embodiment, such as... Figure 1 As shown, the surge protection circuit 200 includes an energy storage start-up unit 201, a main circuit switch unit 202, a surge switch unit 203, a primary surge protection unit 204, and a secondary surge protection unit 205.

[0037] Please continue to refer to this. Figure 1 The energy storage starting unit 201 is connected to the input power supply 101. The input power supply 101 can be any form of current input source or voltage input source, and this embodiment does not impose any restrictions.

[0038] The input terminal of the main circuit switching unit 202 is connected to the energy storage starting unit 201, and the output terminal of the main circuit switching unit 202 is connected to the load 102. The load 102 may include the subsequent circuitry of the surge protection circuit 200. In some embodiments, the first terminal of the main circuit switching unit 202 may be connected to the energy storage starting unit 201, the second terminal of the main circuit switching unit 202 may be connected to the load 102, and the third terminal of the main circuit switching unit 202 may be connected to the input power supply 101.

[0039] When the input power supply 101 is connected, the energy storage starting unit 201 controls the main circuit switching unit 202 to be turned on, thereby connecting the input power supply 101 and the load 102 through the main circuit switching unit 202. In other words, when the main circuit switching unit 202 is turned on, the path between the input power supply 101 and the load 102 is connected. Similarly, if the main circuit switching unit 202 is turned off, the path between the input power supply 101 and the load 102 will also be disconnected.

[0040] Optionally, the energy storage starting unit 201 may include at least one switching element, and the main circuit switching unit 202 may also include at least one switching element. Further optionally, the switching element in the energy storage starting unit 201 and the switching element in the main circuit switching unit 202 may be the same or different.

[0041] The switching elements include, but are not limited to, mechanical switches, relays, diodes, insulated-gate bipolar transistors (IGBTs), or metal-oxide-semiconductor field-effect transistors (MOSFETs). For example, the energy storage startup unit 201 may include a relay, and the main circuit switching unit 202 may include a transistor. The relay turns on after the input power supply 101 is connected and controls the transistor to turn on.

[0042] Please continue to refer to this. Figure 1The surge switch unit 203 is connected to the main circuit switch unit 202, the input power supply 101, and the first connection point V1. The first connection point V1 is the connection point between the input power supply 101 and the input terminal of the main circuit switch unit 202.

[0043] In some embodiments, the first end of the surge switch unit 203 can be connected to the third end of the main circuit switch unit 202, the second end of the surge switch unit 203 can be connected to the first end of the main circuit switch unit 202, and the third end of the surge switch unit 203 is grounded. The first connection point V1 can be the connection point between the first end of the surge switch unit 203 and the third end of the main circuit switch unit 202.

[0044] Optionally, the surge switch unit 203 may include at least one switching element. For example, the surge switch unit 203 and the main circuit switch unit 202 may be implemented using N-type transistors and P-type transistors to control the main circuit switch unit 202 to disconnect after the surge switch unit 203 is turned on.

[0045] Please continue to refer to this. Figure 1 Both the primary surge protection unit 204 and the secondary surge protection unit 205 are connected in parallel at the first connection point and the output terminal of the main circuit switching unit 202. Furthermore, the primary surge protection unit 204 is also connected to the input power supply 101. It is understood that the first connection point V1 is also connected to the first terminal of the secondary surge protection unit 205, and the second terminal of the secondary surge protection unit 205 is connected to the output terminal of the main circuit switching unit 202. Optionally, the first connection point V1 can be connected to one end of the secondary surge protection unit 205 via a resistor.

[0046] Optionally, the primary surge protection unit 204 and the secondary surge protection unit 205 can be components for absorbing surge voltages, including but not limited to varistors. The components used for absorbing surge voltages in the primary surge protection unit 204 and the secondary surge protection unit 205 can be different.

[0047] Furthermore, during the process of connecting the input power supply 101 and the load 102 through the main circuit switching unit 202, if a surge occurs, the input voltage of the input power supply 101 will be greater than or equal to the first voltage value.

[0048] Understandably, if a surge occurs, the current or voltage of the secondary surge protection unit 205 will change abruptly, and a certain voltage will be generated at the first terminal of the secondary surge protection unit 205, so that the first connection receives the first surge voltage or the second surge voltage.

[0049] If the input voltage of the input power supply 101 is between the first voltage value and the second voltage value, that is, if the input voltage is greater than or equal to the first voltage value and less than or equal to the second voltage value, the first surge voltage at the first connection can control the first-level surge protection unit 204 to conduct, so that the first-level surge protection unit 204 absorbs the first surge voltage, and the first surge voltage controls the surge switch unit 203 to conduct, so that the main circuit switch unit 202 is disconnected. In other words, if the surge is small, the first surge voltage received at the first connection will, on the one hand, control the first-level surge protection unit 204 to conduct, and absorb the first surge voltage through the first-level surge protection unit 204; on the other hand, the first surge voltage will also control the surge switch unit 203 to conduct, so that the main circuit switch unit 202 is disconnected, and the main circuit switch unit 202 disconnects the path between the input power supply 101 and the load 102, thereby improving safety.

[0050] Furthermore, if the input voltage is greater than the second voltage value, that is, if the surge is large, the second surge voltage at the first connection point is absorbed by the secondary surge protection unit 205. It should be noted that the second voltage value is greater than the first voltage value. Therefore, when the input voltage is greater than the second voltage value, the second surge voltage will still control the surge switch unit 203 to conduct and the main circuit switch unit 202 to disconnect, thereby disconnecting the path between the input power supply 101 and the load 102.

[0051] In the surge protection circuit 200 described above, the energy storage start-up unit 201 is used to control the main circuit switch unit 202 to be turned on when the input power supply 101 is connected, so as to connect the path between the input power supply 101 and the load 102 through the main circuit switch unit 202. During the process of connecting the input power supply 101 and the load 102 through the main circuit switching unit 202, if the input voltage of the input power supply 101 is between the first voltage value and the second voltage value, the first surge voltage at the first connection can control the first-level surge protection unit 204 to conduct, so that the first-level surge protection unit 204 can absorb the first surge voltage, and the surge switch unit 203 can be turned on to disconnect the main circuit switching unit 202. If the input voltage is greater than the second voltage value, the second surge voltage at the first connection can be absorbed by the second-level surge protection unit 205. Therefore, on the one hand, the path between the input power supply 101 and the load 102 can be disconnected in time when a surge occurs, improving safety. On the other hand, when the surge is small, the first-level surge protection unit 204 can absorb the first surge voltage, and when the surge is large, the second-level surge protection unit 205 can absorb the second surge voltage. In this way, the safety of the surge protection circuit 200 can be further improved through two-level protection.

[0052] Figure 2This is a schematic diagram of another surge protection circuit in one embodiment. In an exemplary embodiment, optionally, such as... Figure 2 As shown, the surge switch unit 203 includes a first transistor Q1.

[0053] In this circuit, the collector of the first transistor Q1 is connected to the main circuit switching unit 202 and the input power supply 101, the base of the first transistor Q1 is connected to the first connection point V1, and the emitter of the first transistor Q1 is grounded. It can be understood that the base of the first transistor Q1 is also the first terminal of the surge switch unit 203, the collector of the first transistor Q1 is also the second terminal of the surge switch unit 203, and the emitter of the first transistor Q1 is also the third terminal of the surge switch unit 203.

[0054] Please continue to refer to this. Figure 2 When no surge occurs, the voltage at the first connection V1 is low, so the first transistor Q1 is in the off state. When a surge occurs, the surge voltage at the first connection V1 will be greater than the first voltage value. Thus, the first transistor Q1 can be turned on by either the first surge voltage or the second surge voltage.

[0055] In the above embodiment, since the surge switch unit 203 includes a first transistor Q1, the collector of the first transistor Q1 is connected to the main circuit switch unit 202 and the input power supply 101, the base of the first transistor Q1 is connected to the first connection point V1, and the emitter of the first transistor Q1 is grounded, the first transistor Q1 can be turned on in time by the surge voltage at the first connection point, either the first surge voltage or the second surge voltage.

[0056] Please continue to refer to this. Figure 2 In one exemplary embodiment, optionally, the main circuit switching unit 202 includes a second transistor Q2. The gate of the second transistor Q2 is connected to the collector of the first transistor Q1, and the source of the second transistor Q2 is connected to the base of the first transistor Q1; that is, the source of the second transistor Q2 is connected to the first connection point V1. The drain of the second transistor Q2 is connected to the load 102.

[0057] It is understandable that the gate of the second transistor Q2 is also the first terminal of the main circuit switching unit 202, the drain of the second transistor Q2 is also the second terminal of the main circuit switching unit 202, and the source of the second transistor Q2 is also the first terminal of the main circuit switching unit 202.

[0058] like Figure 2As shown, after the input power supply 101 is connected, it can control the second transistor Q2 to conduct, thereby opening the path between the input power supply 101 and the load 102. In the event of a surge, the first surge voltage or the second surge voltage at the first connection V1 will control the first transistor Q1 to conduct. When the first transistor Q1 is conducting, the gate and source of the second transistor Q2 are short-circuited, thus turning off the second transistor Q2, and the path between the input power supply 101 and the load 102 is subsequently disconnected.

[0059] In the above embodiment, the main circuit switching unit 202 includes a second transistor Q2; the gate of the second transistor Q2 is connected to the collector of the first transistor Q1, the source of the second transistor Q2 is connected to the base of the first transistor Q1, and the drain of the second transistor Q2 is connected to the load 102. Therefore, by turning on the first transistor Q1, the second transistor Q2 can be controlled to turn off in a timely manner, so as to cut off the path between the input power supply 101 and the load 102 in time when a surge occurs, protecting the subsequent circuit from damage.

[0060] Figure 3 This is a schematic diagram of a primary surge protection unit in one embodiment, as shown below. Figure 3 As shown, the primary surge protection unit 204 includes a surge absorption element 2041 and a first switching subunit 2042. The first switching subunit 2042 is connected to the surge absorption element 2041 and the first connection point V1.

[0061] Please continue to refer to this. Figure 3 When the input voltage is between the first voltage value and the second voltage value, the first connection V1 receives a first surge voltage. This first surge voltage at the first connection V1 can then control the first switching subunit 2042 to turn on. When the first switching subunit 2042 is on, the surge voltage can be absorbed by the surge absorption element 2041. The surge absorption element 2041 includes at least one element capable of absorbing surge voltage or surge current, such as... Figure 2 The varistor RV1 in the middle.

[0062] It is understandable that when the input voltage is greater than the second voltage value, the second surge voltage at the first connection V1 can still control the first switch subunit 2042 to conduct.

[0063] It should be noted that when the input voltage is between the first voltage value and the second voltage value, the first connection V1 receives the first surge voltage from the first terminal of the secondary surge protection unit 205.

[0064] In the above embodiment, since the first-level surge protection unit 204 includes a first switching subunit 2042 and a surge absorption element 2041, and the first switching subunit 2042 is connected to the surge absorption element 2041 and the first connection point respectively, when the input voltage is between the first voltage value and the second voltage value, the first switching subunit 2042 can be turned on by the first surge voltage at the first connection point, so that the surge absorption element 2041 can absorb the first surge voltage and realize the first-level surge protection.

[0065] Please continue to refer to this. Figure 2 In one exemplary embodiment, optionally, the first switching subunit 2042 includes a third transistor Q3 and a first Zener diode ZD3. The gate and source of the third transistor Q3 are both connected to the anode of the first Zener diode ZD3, the drain of the third transistor Q3 is connected to the surge absorption element 2041, the source of the third transistor Q3 is grounded, and the cathode of the first Zener diode ZD3 is connected to the first connection point V1. The surge absorption element 2041 can also be connected to the input power supply.

[0066] In the above embodiment, since the first switching subunit 2042 includes a third transistor Q3 and a first Zener diode ZD3; the gate and source of the third transistor Q3 are both connected to the positive terminal of the first Zener diode ZD3, the drain of the third transistor Q3 is connected to the surge absorption element 2041, the source of the third transistor Q3 is also grounded, and the negative terminal of the first Zener diode ZD3 is connected to the first connection point V1, the first switching subunit 2042 can be turned on in a timely and accurate manner by the first surge voltage or the second surge voltage of the first connection point V1.

[0067] Figure 4 This is a schematic diagram of an energy storage start-up unit in one embodiment. In an exemplary embodiment, such as... Figure 4 As shown, optionally, the energy storage start-up unit 201 includes a charging subunit 2011 and a second switching subunit 2012. The charging subunit 2011 and the second switching subunit 2012 are connected in parallel across the two ends of the input power supply 101, and the main circuit switching unit 202 is connected to both ends of the charging subunit 2011.

[0068] Please continue to refer to this. Figure 4 The input power supply 101 is used to charge the charging subunit 2011. That is, after the input power supply 101 is connected, it will first charge the charging subunit 2011. Furthermore, when the voltage across the charging subunit 2011 is greater than a preset charging voltage, the charging subunit 2011 controls the main circuit switching unit 202 to turn on. The preset charging voltage can be set according to actual needs; this embodiment does not impose any restrictions.

[0069] In the above embodiment, since the energy storage start-up unit 201 includes a charging subunit 2011 and a second switching subunit 2012, and the charging subunit 2011 and the second switching subunit 2012 are connected in parallel to the two ends of the input power supply 101, and the main circuit switching unit 202 is connected to the two ends of the charging subunit 2011 respectively, the input power supply 101 can charge the charging subunit 2011. When the voltage across the charging subunit 2011 is greater than the preset charging voltage, the charging subunit 2011 controls the main circuit switching unit 202 to turn on. In this way, the main circuit switching unit 202 can be turned on only after the input voltage is normal, thereby improving the working reliability of the subsequent circuit.

[0070] In one exemplary embodiment, optionally, the charging subunit 2011 includes an energy storage element, and the second switching subunit 2012 includes a second Zener diode ZD2. Optionally, the energy storage element may include at least one capacitor. Figure 2 For example, the energy storage element may include capacitor C7.

[0071] In this configuration, the two ends of the energy storage element are connected to the input power supply 101. The anode and cathode of the second Zener diode ZD2 are connected to the cathode and anode of the input power supply 101, respectively. That is, the anode of the second Zener diode ZD2 is connected to the cathode of the input power supply 101, and the cathode of the second Zener diode ZD2 is connected to the anode of the input power supply 101. Furthermore, the main circuit switching unit 202 is connected to both ends of the energy storage element. In one embodiment, the first and third terminals of the main circuit switching unit 202 can be connected to both ends of the energy storage element, respectively.

[0072] Please continue to refer to this. Figure 2 DC-IN represents the positive terminal of input power supply 101, and DC-OUT represents the negative terminal of input power supply 101. At the instant the input power supply 101 is connected, since the voltage across C7 cannot change abruptly, the main circuit switching unit 202 is not turned on at this time. Input power supply 101 first charges C7. When C7 is charged to the regulated voltage of the second Zener diode ZD2, the voltage across the energy storage element is greater than the preset charging voltage, and the second Zener diode ZD2 is broken down. The main circuit switching unit 202 is turned on, and the path between input power supply 101 and load 102 is connected.

[0073] In the above embodiment, the charging subunit 2011 includes an energy storage element, and the second switching subunit 2012 includes a second Zener diode ZD2. The two ends of the energy storage element are connected to the input power supply 101, and the positive and negative terminals of the second Zener diode ZD2 are respectively connected to the negative and positive terminals of the input power supply 101. The main circuit switching unit 202 is connected to both ends of the energy storage element. Therefore, after the input power supply 101 is connected, it first charges the energy storage element, and then controls the main circuit switching unit 202 to conduct only when the voltage across the energy storage element is greater than a preset charging voltage, thereby improving the reliability of the conduction path between the input power supply 101 and the load 102.

[0074] In one exemplary embodiment, please continue to refer to Figure 2 Optionally, the surge protection circuit 200 also includes at least one of the following:

[0075] (1) First resistor R1. The first resistor R1 is connected to the negative terminal of the input power supply 101 and the second Zener diode ZD2. (2) Second resistor R2. The second resistor R2 is connected to the positive and negative terminals of the second Zener diode ZD2. The first resistor R1 and the second resistor R2 can be resistors used for current limiting.

[0076] In the above embodiments, the surge protection circuit 200 further includes at least one of a first resistor and a second resistor. Since the first resistor is connected to the negative terminal of the input power supply 101 and the second Zener diode ZD2 respectively, and the second resistor is connected to the positive and negative terminals of the second Zener diode ZD2 respectively, the working stability and reliability of the energy storage start-up unit 201 can be improved by the first resistor or the second resistor.

[0077] Please continue to refer to this. Figure 2 In one embodiment, the secondary surge protection unit 205 is connected to the input power supply 101 via a first resistor R1 and a second resistor R2. At the instant the input power supply 101 is connected, the current will sequentially pass through V3, the first resistor R1, the second resistor R2, and the secondary surge protection unit 205 to reach the ground terminal GND_DC.

[0078] In one exemplary embodiment, optionally, if the input voltage of the input power supply 101 is greater than the second voltage value, the secondary surge protection unit 205 is controlled to blow by the input voltage.

[0079] In this embodiment, the secondary surge protection unit 205 may include components such as fuses or circuit breakers that are melted or burned out when the input voltage exceeds the second voltage value. Optionally, the secondary surge protection unit 205 may be a high-voltage instantaneous resistor.

[0080] Please continue to refer to this. Figure 2 The secondary surge protection unit 205 includes Figure 2Taking the high-voltage fast-acting resistor RT1 as an example, when the surge is small, the input power supply 101 is between the first voltage value and the second voltage value. Although the main circuit switching unit 202 is open, and the path between the input power supply 101 and the load 102 is broken, due to the presence of the secondary surge protection unit 205, the input voltage will pass through the first resistor R1, the second resistor R2, and RT1 in sequence before reaching the ground terminal GND_DC. That is to say, at this time, the surge protection circuit 200 still has a loop current. However, when the surge is large, the input power supply 101 is greater than the second voltage value, and the current or voltage on RT1 changes abruptly, causing RT1 to be blown. At this time, the surge protection circuit 200 has no loop current.

[0081] It should be noted that if the secondary surge protection unit 205 has blown, the surge protection circuit 200 needs to be replaced with a new secondary surge protection unit 205 before power failure and restart.

[0082] In the above embodiment, if the input voltage of the input power supply 101 is greater than the second voltage value, the secondary surge protection unit 205 is controlled to melt by the input voltage. Therefore, the secondary surge protection unit 205 can make the surge protection circuit 200 free of loop current, thereby further improving the safety of the surge protection unit.

[0083] In one exemplary embodiment, the surge protection circuit 200 may optionally include a filter unit 206. The filter unit 206 is connected to both the input power supply 101 and the energy storage start-up unit 201 to filter the input voltage of the input power supply 101.

[0084] This embodiment does not limit the implementation of the filter unit 206. The filter unit 206 may include, but is not limited to, a capacitor filter circuit, an inductor filter circuit, a resistor-capacitor (RC) filter, an inductor-capacitor (LC) filter, or other complex filter circuits.

[0085] In one embodiment, please refer to Figure 2 Optionally, the input voltage can be filtered through a two-stage LCL filter circuit consisting of common-mode inductors L1 and L2, ensuring that the voltage at V3 is the filtered voltage, thereby reducing electromagnetic noise and spurious signals. This is understandable. Figure 3 In this context, PE stands for Protective Earthing.

[0086] In some embodiments, the surge protection circuit 200 may optionally include at least one of the following:

[0087] (1) Zener diode ZD1. The positive terminal of Zener diode ZD1 is connected to the base of the first transistor Q1, and the negative terminal of Zener diode ZD1 is connected to the drain of the second transistor Q2. Zener diode ZD1 is used to protect the second transistor Q2 from damage during surges.

[0088] (2) Resistor R3. Resistor R3 is connected to the base of the first transistor Q1 and the source of the second transistor Q2.

[0089] (3) Resistor R4. Resistor R4 is connected to the base of the first transistor Q1 and the drain of the second transistor Q2. Resistor R4 is also used to protect the second transistor Q2 from damage during surges. Further optionally, resistor R4 can be connected to the cathode of Zener diode ZD1 and the drain of the second transistor Q2.

[0090] (4) Resistor R5. Resistor R5 is connected to the gate of the third transistor Q3 and the positive terminal of the first Zener diode ZD3.

[0091] (5) Resistor R6. Resistor R6 is connected to the source of the third transistor Q3 and the positive terminal of the first Zener diode ZD3. Optionally, resistor R5 is connected to resistor R6.

[0092] (6) Zener diode ZD4. The positive terminal of Zener diode ZD4 is grounded, and the negative terminal of Zener diode ZD4 is connected to the gate of the third transistor Q3. Zener diode ZD4 is used to protect the gate-gate protection voltage of the third transistor Q3.

[0093] (7) Capacitor C9. Capacitor C9 is connected in parallel with the secondary surge protection unit.

[0094] To more clearly illustrate the surge protection circuit 200 of this application, the following will combine... Figure 2 Please refer to the following explanation. Figure 2 After the input voltage is filtered by LCL, it reaches V3. At the moment the input power supply 101 is turned on, since the voltage across C7 cannot change abruptly, the second transistor Q2 is turned off. The current flows through V3, R1, R2, RT1 and GND_DC to charge C7. When the voltage across C7 reaches the voltage regulation value of the second Zener diode ZD2, the second transistor Q2 is turned on, and the main circuit current between DC-IN and GND_DC forms a loop.

[0095] When a surge occurs in DC-IN or the output capacitor C3 is short-circuited, the voltage at the first connection V1 becomes very high, causing a sudden change in the current or voltage of RT1. This generates a large voltage across RT1, causing the first transistor Q1 to close and short-circuit the gate-source (GS) drive of the second transistor Q2, thus opening the second transistor Q2. When the input voltage is between the first and second voltage values, the first-level protection activates, the first Zener diode ZD3 is reverse-biased, and the third transistor Q3 conducts, releasing the surge voltage at V3 through RV1. At this time, RT1 has not yet blown, and the input voltage reaches the ground terminal GND_DC after passing through the first resistor R1, the second resistor R2, and RT1. The surge protection circuit 200 still has loop current. When the input voltage exceeds the second voltage value, the first-level protection fails, the second-level protection activates, RT1 blows, and the surge protection circuit 200 has no loop current.

[0096] It is evident that the surge protection circuit 200 of this application can protect the subsequent circuit from damage.

[0097] Figure 5 This is a schematic diagram of an energy storage system in one embodiment, such as... Figure 5 As shown, in one embodiment, an energy storage system 500 is also provided, which includes the surge protection circuit 200 of any of the above.

[0098] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A surge protection circuit, characterized in that, The surge protection circuit includes: The energy storage starting unit is connected to the input power supply; The main circuit switching unit has its input terminal connected to the energy storage starting unit and its output terminal connected to the load. When the input power is connected, the energy storage starting unit controls the main circuit switching unit to be turned on so as to connect the path between the input power and the load through the main circuit switching unit. A surge switch unit is connected to the main circuit switch unit, the input power supply, and the first connection point, respectively; the first connection point is the connection point between the input power supply and the input terminal of the main circuit switch unit. A primary surge protection unit and a secondary surge protection unit are provided, both of which are connected in parallel at the first connection point and the output terminal of the main circuit switching unit. The primary surge protection unit is also connected to the input power supply. During the process of connecting the path through the main circuit switching unit, if the input voltage of the input power supply is between the first voltage value and the second voltage value, the first surge voltage at the first connection point controls the first-stage surge protection unit to conduct, so that the first-stage surge protection unit absorbs the first surge voltage, and the surge switch unit is turned on by the first surge voltage to make the main circuit switching unit turn off; if the input voltage is greater than the second voltage value, the second surge protection unit absorbs the second surge voltage at the first connection point.

2. The circuit according to claim 1, characterized in that, The surge switch unit includes a first transistor; the collector of the first transistor is connected to the main circuit switch unit and the input power supply, the base of the first transistor is connected to the first connection point, and the emitter of the first transistor is grounded.

3. The circuit according to claim 2, characterized in that, The main circuit switching unit includes a second transistor; the gate of the second transistor is connected to the collector of the first transistor, the source of the second transistor is connected to the base of the first transistor, and the drain of the second transistor is connected to the load.

4. The circuit according to any one of claims 1-3, characterized in that, The primary surge protection unit includes a first switching subunit and a surge absorption element; the first switching subunit is connected to the surge absorption element and the first connection point respectively. When the input voltage is between the first voltage value and the second voltage value, the first switch subunit is turned on by the first surge voltage at the first connection so as to absorb the first surge voltage through the surge absorption element.

5. The circuit according to claim 4, characterized in that, The first switching subunit includes a third transistor and a first Zener diode; the gate and source of the third transistor are both connected to the positive terminal of the first Zener diode, the drain of the third transistor is connected to the surge absorption element, the source of the third transistor is also grounded, and the negative terminal of the first Zener diode is connected to the first connection point.

6. The circuit according to any one of claims 1-3, characterized in that, The energy storage start-up unit includes a charging subunit and a second switching subunit; the charging subunit and the second switching subunit are connected in parallel to the two ends of the input power supply, and the main circuit switching unit is connected to the two ends of the charging subunit respectively; The input power supply is used to charge the charging subunit. When the voltage across the charging subunit is greater than the preset charging voltage, the charging subunit controls the main circuit switching unit to turn on.

7. The circuit according to claim 6, characterized in that, The charging subunit includes an energy storage element, and the second switching subunit includes a second Zener diode; The two ends of the energy storage element are connected to the input power supply, the positive and negative terminals of the second Zener diode are respectively connected to the negative and positive terminals of the input power supply, and the main circuit switching unit is respectively connected to the two ends of the energy storage element.

8. The circuit according to claim 7, characterized in that, The surge protection circuit further includes at least one of the following: A first resistor; the first resistor is connected to both the input power supply and the negative terminal of the second Zener diode; The second resistor is connected to the positive and negative terminals of the second Zener diode, respectively.

9. The circuit according to any one of claims 1-3, characterized in that, If the input voltage of the input power supply is greater than the second voltage value, the secondary surge protection unit is controlled to melt by the input voltage.

10. An energy storage system, characterized in that, The energy storage system includes the surge protection circuit as described in any one of claims 1-9.

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