Surge suppression circuit and method and AC / DC converter

Abstract

The invention discloses a surge suppression circuit and method and an AC / DC converter, and relates to the technical field of electronic power, and the disclosed surge suppression circuit comprises a control module, a switching device and a surge suppression device. According to the invention, the surge voltage slope in the power grid is determined through the control module; the control module controls the on-off state of the switching device according to the surge voltage slope; when the on-off state of the switching device is a conducting state, the surge suppression device is connected to a power grid; when the surge suppression device is connected to a power grid, surge voltage in the power grid is suppressed. The surge suppression device is connected to the power grid to suppress the surge voltage when the switching device is controlled to be in the on state by the surge voltage slope, so that the surge suppression device is activated by the switching device instead of being directly activated by the surge voltage, the voltage grade of the surge suppression device is not required, and the surge suppression device can be used for suppressing the surge voltage. And the surge suppression effect of the surge suppression device is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a surge suppression circuit, method and AC / DC converter. Background Art

[0002] With the continuous development of the energy industry, AC / DC converters are increasingly used, and surge suppression has limited power density and cost.

[0003] In order to better suppress surges, current technology uses ports plus surge suppression devices, such as thyristor surge suppressors (TSS) devices, that is, the AC / DC converter in the power grid introduces a surge suppression device connected to the corresponding port. The surge suppression device is activated when the surge voltage received from the power grid reaches a threshold, thereby suppressing the surge voltage in the power grid.

[0004] However, the above method directly activates the surge suppression device by the surge voltage, and the current AC / DC converter has a high withstand voltage. The high withstand voltage requires the voltage level of the surge suppression device to be higher, resulting in the surge suppression device being activated only when the surge voltage is high, and the surge suppression effect is poor.

[0005] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0006] The main purpose of the present application is to provide a surge suppression circuit, method and AC / DC converter, aiming to solve the technical problem that the surge suppression device is directly activated by the surge voltage in the prior art, and the surge suppression effect is poor when the voltage level of the surge suppression device is high.

[0007] To achieve the above object, the present application provides a surge suppression circuit, the circuit comprising: a control module, a switch device and a surge suppression device;

[0008] The control module is connected to the control end of the switch device, the first end of the switch device is connected to the first end of the power grid, the second end of the switch device is connected to the first end of the surge suppression device, and the second end of the surge suppression device is connected to the second end of the power grid;

[0009] The control module is used to detect the slope of the surge voltage in the power grid, and when the slope is greater than a preset threshold, control the switch device to conduct, so as to connect the surge suppression device to the power grid to suppress the surge voltage in the power grid.

[0010] In one embodiment, the control module is further configured to control the switch device to be disconnected to disconnect the surge suppression device from the power grid when it is detected that the slope of the surge voltage in the power grid is less than or equal to the preset threshold.

[0011] In one embodiment, a first inductor is provided in the power grid, and the control module is connected to two ends of the first inductor;

[0012] The control module is further used to collect the surge voltage across the first inductor;

[0013] The control module is further used to determine the surge voltage slope according to the variation amplitude of the surge voltage.

[0014] In one embodiment, the control module includes: a transformer unit and a drive unit;

[0015] The transformer unit is connected to two ends of the first inductor, and the driving unit is connected to the transformer unit and the control end of the switch device respectively;

[0016] The transformer unit is used to generate a secondary-side sensing signal according to the surge voltage slope, and output the secondary-side sensing signal to the driving unit;

[0017] The driving unit is used to rectify the secondary side induction signal to obtain a DC driving signal;

[0018] The driving unit is further used to control the conduction state of the switching device through the DC driving signal.

[0019] In one embodiment, the driving unit is further used to determine whether the voltage value of the DC driving signal reaches a preset voltage threshold;

[0020] The driving unit is further configured to control the switching device to be in the on state through the DC driving signal when the voltage value of the DC driving signal reaches the preset voltage threshold.

[0021] In one embodiment, the transformer unit is further configured to output a secondary-side sensing signal whose voltage amplitude reaches a preset amplitude calibration value when the surge voltage slope reaches a preset slope;

[0022] The driving unit is used to rectify the secondary-side induction signal to obtain the DC driving signal whose voltage value reaches the preset voltage threshold.

[0023] In one embodiment, the transformer unit includes: a first winding and a second winding;

[0024] The first winding and the second winding form a transformer structure;

[0025] The first end of the first winding is connected to the first end of the first inductor, and the second end of the first winding is connected to the second end of the first inductor;

[0026] A first end of the second winding is connected to a first end of the driving unit, and a second end of the second winding is connected to a second end of the driving unit.

[0027] In one embodiment, the driving unit includes: a first diode, a first capacitor and a first comparator;

[0028] The anode of the first diode is connected to the first end of the second winding, the cathode of the first diode is connected to the first end of the first capacitor and the non-inverting input end of the first comparator, the second end of the first capacitor is respectively connected to the second end of the second winding and the first end of the power grid, the inverting input end of the first comparator is connected to a reference source, and the output end of the first comparator is connected to the control end of the switching device.

[0029] In one embodiment, the power grid is further provided with a first resistor and a second capacitor;

[0030] The first end of the first resistor is connected to the first end of the first inductor, and the second end of the first resistor is connected to the second end of the surge suppression device;

[0031] The first end of the second capacitor is connected to the second end of the first inductor, and the second end of the second capacitor is connected to the first end of the switch device.

[0032] In one embodiment, the switching device is a thyristor;

[0033] The control end of the thyristor is connected to the output end of the first comparator, the anode of the thyristor is connected to the first end of the surge suppression device, and the cathode of the thyristor is connected to the first end of the power grid.

[0034] In one embodiment, the switching device is a transistor;

[0035] The gate of the transistor is connected to the output terminal of the first comparator, the input terminal of the transistor is connected to the first terminal of the surge suppression device, and the output terminal of the transistor is connected to the first terminal of the power grid.

[0036] In addition, to achieve the above objectives, the present application also proposes a surge suppression method based on the surge suppression circuit described above, the method comprising:

[0037] Determine the surge voltage slope in the power grid;

[0038] Controlling the on / off state of the switching device according to the surge voltage slope;

[0039] Wherein, when the on-off state of the switch device is the on state, the surge suppression device is connected to the power grid, so that the surge suppression device suppresses the surge voltage in the power grid.

[0040] In addition, to achieve the above-mentioned purpose, the present application also proposes an AC / DC converter, wherein the AC / DC converter includes the surge suppression circuit described above.

[0041] One or more technical solutions proposed in this application have at least the following technical effects:

[0042] The surge suppression circuit involved in the present application includes: a control module, a switch device and a surge suppression device, the control module is connected to the control end of the switch device, the first end of the switch device is connected to the first end of the power grid, the second end of the switch device is connected to the first end of the surge suppression device, and the second end of the surge suppression device is connected to the second end of the power grid. The present application determines the surge voltage slope in the power grid through the control module; the control module controls the on-off state of the switch device according to the surge voltage slope; when the on-off state of the switch device is the on state, the surge suppression device is connected to the power grid; when the surge suppression device is connected to the power grid, the surge voltage in the power grid is suppressed. Since the present application controls the switch device to be in the on state by the surge voltage slope, the surge suppression device is connected to the power grid to suppress the surge voltage, so that the surge suppression device is activated by the switch device instead of being directly activated by the surge voltage. Therefore, compared with the prior art, the present application has no requirements for the voltage level of the surge suppression device, and the surge suppression device will not be activated only when the surge voltage is high, which effectively improves the surge suppression effect of the surge suppression device. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 This is a schematic structural diagram of a first embodiment of a surge suppression circuit of the present application;

[0046] Figure 2 This is a schematic structural diagram of a second embodiment of a surge suppression circuit of the present application;

[0047] Figure 3 This is a schematic structural diagram of a transformer unit in the second embodiment of the surge suppression circuit of the present application;

[0048] Figure 4 This is a schematic diagram of the structure of a driving unit in the third embodiment of the surge suppression circuit of the present application;

[0049] Figure 5 This is a first circuit schematic diagram of the third embodiment of the surge suppression circuit of the present application;

[0050] Figure 6 A second circuit schematic diagram of the third embodiment of the surge suppression circuit of the present application;

[0051] Figure 7 This is a flow chart of an embodiment of a surge suppression method of the present application.

[0052] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0053] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0054] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0055] The main solution of the embodiment of the present application is: the control module determines the surge voltage slope in the power grid; the control module controls the on-off state of the switching device according to the surge voltage slope; when the on-off state of the switching device is the on state, the surge suppression device is connected to the power grid; when the surge suppression device is connected to the power grid, the surge voltage in the power grid is suppressed.

[0056] Since the existing technology directly activates the surge suppression device through the surge voltage, and the current AC / DC converter has a high withstand voltage, the higher withstand voltage requires the voltage level of the surge suppression device to be higher, resulting in the surge suppression device being activated only when the surge voltage is high, and the surge suppression effect is poor.

[0057] The present application provides a solution, in which a surge suppression device is connected to the power grid to suppress surge voltage when a switching device is in an on state controlled by a surge voltage slope, thereby activating the surge suppression device by the switching device rather than directly activating the surge suppression device by the surge voltage. Therefore, compared with the prior art, the present application has no requirements for the voltage level of the surge suppression device, and the surge suppression device will not be activated only when the surge voltage is high, thereby effectively improving the surge suppression effect of the surge suppression device.

[0058] Based on this, the embodiment of the present application provides a surge suppression circuit, referring to Figure 1 , Figure 1 It is a structural schematic diagram of the first embodiment of the surge suppression circuit of the present application.

[0059] In this embodiment, the surge suppression circuit includes: a control module 100, a switch device 200 and a surge suppression device 300;

[0060] The control module 100 is connected to the control end of the switch device 200, the first end of the switch device 100 is connected to the first end a of the power grid, the second end of the switch device 200 is connected to the first end of the surge suppression device 300, and the second end of the surge suppression device 300 is connected to the second end b of the power grid.

[0061] It should be noted that the above surge suppression circuit can be applied to an AC / DC converter, which is arranged in a power grid. The first end a of the power grid and the second end b of the power grid can be two ports derived from the power grid for connecting a load.

[0062] The control module 100 is used to determine the surge voltage slope in the power grid.

[0063] It should be noted that the above-mentioned surge voltage slope may be the speed at which the surge voltage rises or falls in a very short time. The surge voltage may be an instantaneous high voltage generated by an AC / DC converter in the power grid.

[0064] In a specific implementation, the control module 100 can monitor the voltage in the power grid. When it is detected that there is an instantaneous high voltage reaching a set threshold at a certain moment, the instantaneous high voltage is determined to be a surge voltage, and the surge voltage slope of the surge voltage at that moment can be determined.

[0065] like Figure 1 As shown, a first inductor L1 is provided in the power grid, and the control module 100 is connected to two ends of the first inductor L1.

[0066] The control module 100 is further used to collect the surge voltage across the first inductor L1.

[0067] The control module 100 is further configured to determine the surge voltage slope according to the variation amplitude of the surge voltage.

[0068] In a specific implementation, the control module 100 can collect the voltage across the first inductor L1, and when the voltage across the first inductor L1 is an instantaneous high voltage that reaches a set threshold, determine that the voltage across the first inductor L1 is a surge voltage, and further determine the change amplitude of the surge voltage at the current moment, and determine the surge voltage slope through the change amplitude.

[0069] The control module 100 is also used to control the on-off state of the switching device 200 according to the surge voltage slope: when the slope is greater than a preset threshold, the switching device is controlled to be turned on to connect the surge suppression device to the power grid to suppress the surge voltage in the power grid; when it is detected that the slope of the surge voltage in the power grid is less than or equal to the preset threshold, the switching device is controlled to be turned off to disconnect the surge suppression device from the power grid.

[0070] In a specific implementation, the control module 100 can convert the surge voltage slope into a corresponding DC voltage, and generate a DC drive signal with a voltage amplitude of the DC voltage to the control end of the switching device 200, and control the on / off state of the switching device 200 through the DC drive signal.

[0071] The switch device 200 is used to connect the surge suppression device 300 to the power grid when the on-off state is the on state.

[0072] It should be noted that the switch device 200 may be a device whose on / off state is controlled by the control module 100, such as a semiconductor device such as a MOS tube, an IGBT, and a thyristor. The on / off state is the on state when closed and the off state when open.

[0073] In a specific implementation, when the control end of the switch device 200 receives the DC drive signal input by the control module 100, it is determined whether the DC voltage of the DC drive signal reaches the conduction condition. For example, when the switch device 200 is an NMOS tube, the conduction condition may be that the DC voltage received by the gate is greater than the source voltage, and the difference between the two reaches the threshold voltage of the NMOS tube. The switch device 200 is closed when the DC voltage reaches the conduction condition and enters the conduction state. In the conduction state, the circuit between the surge suppression device 300 and the grid port (i.e., the first end a of the grid and the second end b of the grid) can be conducted, thereby connecting the surge suppression device 300 to the grid.

[0074] In addition, when the DC voltage does not reach the conduction condition, the surge suppression device 300 can be disconnected from the grid port.

[0075] The surge suppression device 300 is used to suppress the surge voltage in the power grid when connected to the power grid.

[0076] In a specific implementation, the surge suppression device 300 can be activated when connected to the power grid, respond to the surge voltage in the power grid, and suppress the surge voltage by guiding the surge voltage to the ground wire or other safe paths to ensure the safety of the equipment.

[0077] It should be understood that since whether the above-mentioned surge suppression device 300 is connected to the power grid is controlled by the switching device 200, there are no requirements for its activation and voltage level. A capacitor with a larger capacitance, a TSS device with a low withstand voltage level, a varistor, or a circuit using a varistor in series with a gas discharge tube can be used.

[0078] The surge suppression circuit provided in this embodiment includes: a control module, a switch device and a surge suppression device, the control module is connected to the control end of the switch device, the first end of the switch device is connected to the first end of the power grid, the second end of the switch device is connected to the first end of the surge suppression device, and the second end of the surge suppression device is connected to the second end of the power grid. In this embodiment, the surge voltage slope in the power grid is determined by the control module; the control module controls the on-off state of the switch device according to the surge voltage slope; when the on-off state of the switch device is the on state, the surge suppression device is connected to the power grid; when the surge suppression device is connected to the power grid, the surge voltage in the power grid is suppressed. Since in this embodiment, when the switch device is in the on state controlled by the surge voltage slope, the surge suppression device is connected to the power grid to suppress the surge voltage, the surge suppression device is activated by the switch device instead of being directly activated by the surge voltage. Therefore, compared with the prior art, this embodiment has no requirements for the voltage level of the surge suppression device, and the surge suppression device will not be activated only when the surge voltage is high, which effectively improves the surge suppression effect of the surge suppression device.

[0079] Based on the first embodiment of the present application, the second embodiment of the present application is proposed. In the second embodiment of the present application, the same or similar contents as those of the first embodiment can be referred to the above introduction, and will not be repeated later. Figure 2 , Figure 2 It is a structural schematic diagram of the second embodiment of the surge suppression circuit of the present application.

[0080] In this embodiment, the control module 100 includes: a transformer unit 101 and a driving unit 102 .

[0081] The transformer unit 101 is connected to two ends of the first inductor L1 , and the driving unit 102 is connected to the transformer unit 101 and a control end of the switch device 200 , respectively.

[0082] The transformer unit 101 is used to generate a secondary-side sensing signal according to the surge voltage slope, and output the secondary-side sensing signal to the driving unit 102 .

[0083] In a specific implementation, the transformer unit 101 can collect the surge voltage across the first inductor L1 through the primary side, induce a corresponding secondary-side sensing signal on the secondary side according to the surge voltage slope, and then output the secondary-side sensing signal to the driving unit 102 .

[0084] refer to Figure 3 , Figure 3 Schematic diagram of the structure of the transformer unit in the second embodiment of the surge suppression circuit of the present application. Figure 3 In the embodiment, the transformer unit 101 includes: a first winding N1 and a second winding N2.

[0085] The first winding N1 and the second winding N2 form a transformer structure; the first end of the first winding N1 is connected to the first end of the first inductor L1, and the second end of the first winding N1 is connected to the second end of the first inductor L1; the first end of the second winding N2 is connected to the first end of the driving unit 102, and the second end of the second winding N2 is connected to the second end of the driving unit 102.

[0086] like Figure 3 As shown, the first winding N1 can be used as the primary side of the transformer, and the second winding N2 can be used as the secondary side of the transformer. The first winding N1 is connected to both ends of the first inductor L1, and the surge voltage at both ends of the first inductor L1 can be collected. When the surge voltage changes to form a surge voltage slope, a changing magnetic field can be generated around it. The changing magnetic field will pass through the second winding N2, generate an induced electromotive force in the second winding N2, and form a secondary side induction signal.

[0087] The driving unit 102 is used to rectify the secondary-side sensing signal to obtain a DC driving signal.

[0088] The driving unit 102 is further configured to control the conduction state of the switching device 200 through the DC driving signal.

[0089] In a specific implementation, since the secondary side induction signal is generated by the above-mentioned transformer structure 101 through electromagnetic induction and is an AC signal, the above-mentioned driving unit 102 can rectify the secondary side induction signal to obtain a DC driving signal, and then output the DC driving signal to the control end of the switching device 200 to control the conduction state of the switching device 200 based on the DC driving signal.

[0090] The control module of this embodiment includes a transformer unit and a drive unit. The transformer unit generates a secondary-side sensing signal according to the surge voltage slope, and outputs the secondary-side sensing signal to the drive unit. Then the drive unit rectifies the secondary-side sensing signal, and uses the DC driving signal obtained by rectification to control the conduction state of the switch device. Since this embodiment converts the surge voltage slope into the secondary-side sensing signal by electromagnetic induction through the transformer structure in the transformer unit, the output DC driving signal can accurately reflect the degree of change of the surge voltage, thereby making the control of the switch device more accurate, and effectively improving the accuracy of surge suppression.

[0091] Based on the second embodiment of the present application, the third embodiment of the present application is proposed. In the third embodiment of the present application, the same or similar contents as those of the first embodiment and the second embodiment can be referred to the above introduction, and will not be repeated in the following.

[0092] On this basis, the driving unit 102 is further used to determine whether the voltage value of the DC driving signal reaches a preset voltage threshold.

[0093] It should be noted that the above-mentioned preset voltage threshold may be a threshold for triggering the switch device 200 to be turned on.

[0094] The driving unit 102 is further configured to control the switch device 200 to be in the on state through the DC driving signal when the voltage value of the DC driving signal reaches the preset voltage threshold.

[0095] In a specific implementation, the driving unit 102 may compare the voltage value of the DC driving signal with a preset voltage threshold to determine whether the voltage value of the DC driving signal reaches the preset voltage threshold. When the voltage value of the DC driving signal reaches the preset voltage threshold, the DC driving signal may be used to control the switch device 200 to close, so that the switch device 200 enters the on state. On the contrary, when the voltage value of the DC driving signal does not reach the preset voltage threshold, the DC driving signal may be used to control the switch device 200 to open, so that the switch device 200 enters the off state.

[0096] Furthermore, in this embodiment, the transformer unit 101 is also used to output a secondary-side sensing signal whose voltage amplitude reaches a preset amplitude calibration value when the surge voltage slope reaches a preset slope.

[0097] It should be noted that the above-mentioned preset slope may be a slope threshold value for determining whether the slope is large enough to sense a secondary-side sensing signal whose voltage amplitude reaches a preset amplitude calibration value.

[0098] Correspondingly, the above-mentioned preset amplitude calibration value can be a calibration value for determining whether the voltage is large and can generate a DC driving signal whose voltage value reaches a preset voltage threshold.

[0099] In a specific implementation, when the transformer unit 101 collects a surge voltage and the surge voltage slope reaches a preset slope, a secondary-side sensing signal with a voltage amplitude reaching a preset amplitude calibration value can be sensed on the secondary side.

[0100] The driving unit 102 is used to rectify the secondary-side sensing signal to obtain the DC driving signal whose voltage value reaches the preset voltage threshold.

[0101] In a specific implementation, since the voltage amplitude of the secondary-side sensing signal reaches the preset amplitude calibration value, the driving unit 102 can obtain a rectified driving signal with a voltage value reaching a preset voltage threshold after rectifying the secondary-side sensing signal, so as to control the switching device 200 to close.

[0102] In addition, when the surge voltage slope does not reach the preset slope, the voltage amplitude of the output secondary side sensing signal is lower than the preset amplitude calibration value. It can be determined that the surge voltage change slope at this time is small, and the corresponding surge voltage has a small impact. Therefore, the voltage value of the output rectifier drive signal will be lower than the preset voltage threshold to control the switch device 200 to disconnect without activating the surge threshold device 300.

[0103] refer to Figure 4 , Figure 4 Schematic diagram of a portion of the structure of a driving unit in the third embodiment of the surge suppression circuit of the present application. Figure 4 In the embodiment, the driving unit 102 may include a first diode D1, a first capacitor C1 and a first comparator A1.

[0104] The anode of the first diode D1 is connected to the first end of the second winding N2, the cathode of the first diode D1 is connected to the first end of the first capacitor C1 and the non-inverting input end of the first comparator A1, the second end of the first capacitor C1 is respectively connected to the second end of the second winding N2 and the first end a of the power grid, the inverting input end of the first comparator A1 is connected to the reference source Vref, and the output end of the first comparator A1 is connected to the control end of the switching device 200.

[0105] like Figure 4 As shown, the secondary induction signal output by the second winding N2 can be rectified by the first diode D1 to obtain a DC drive signal, and the DC drive signal is output to the positive input terminal of the first comparator A1. In addition, the DC drive signal can also charge the first capacitor C1, and then the first capacitor C1 outputs the DC drive signal to the positive input terminal of the first comparator A1, and the reference source can output a preset voltage threshold to the inverting input terminal of the first comparator A1. When the voltage value of the DC drive signal reaches the preset voltage threshold, the first comparator A1 can output a high-level drive signal to control the switch device 200 to close, so that the switch device 200 enters the on state and connects the surge suppression device 300 to the power grid. On the contrary, when the voltage value of the DC drive signal does not reach the preset voltage threshold, the first comparator A1 can output a low-level drive signal to control the switch device 200 to disconnect, so that the switch device 200 enters the off state and disconnects the surge suppression device 300 from the power grid.

[0106] Furthermore, if Figure 4As shown, in this embodiment, the power grid is further provided with a first resistor R1 and a second capacitor C2;

[0107] The first end of the first resistor R1 is connected to the first end of the first inductor L1, and the second end of the first resistor R1 is connected to the second end of the surge suppression device 300; the first end of the second capacitor C2 is connected to the second end of the first inductor L1, and the second end of the second capacitor C2 is connected to the first end of the switching device 200.

[0108] It should be noted that the first resistor R1 can consume the energy of the voltage in the grid, thereby suppressing the oscillation of the circuit connected to the grid and ensuring the stable operation of the grid. The second capacitor C2 can absorb the overvoltage in the peak state to prevent the sudden change of voltage from impacting the grid.

[0109] In one possible implementation, refer to Figure 5 , Figure 5 This is a first circuit schematic diagram of the third embodiment of the surge suppression circuit of the present application, wherein the switch device 200 is a thyristor Q1 .

[0110] The control end of the thyristor Q1 is connected to the output end of the first comparator A1 , the anode of the thyristor Q1 is connected to the first end of the surge suppression device 300 , and the cathode of the thyristor Q1 is connected to the first end a of the power grid.

[0111] In a specific implementation, when the voltage value of the DC drive signal reaches the preset voltage threshold, the first comparator A1 can output a high-level drive signal to the control end of the thyristor Q1, so that the thyristor Q1 is forward-conducted, and the surge suppression device 300 is connected to the power grid. On the contrary, when the voltage value of the DC drive signal does not reach the preset voltage threshold, the first comparator A1 can output a low-level drive signal to the control end of the thyristor Q1, so that the thyristor Q1 is reverse-conducted, and the surge suppression device 300 is disconnected from the power grid.

[0112] In another possible implementation, referring to Figure 6 , Figure 6 This is a second circuit schematic diagram of the third embodiment of the surge suppression circuit of the present application, in which the switch device 200 is a transistor Q2.

[0113] The gate of the transistor Q2 is connected to the output terminal of the first comparator, the input terminal of the transistor Q2 is connected to the first terminal of the surge suppression device 300 , and the output terminal of the transistor Q2 is connected to the first terminal a of the power grid.

[0114] It should be noted that the transistor Q2 may be a MOS tube or an IGBT tube. This embodiment uses an NMOS tube as an example, but does not limit this solution.

[0115] In a specific implementation, when the voltage value of the DC drive signal reaches the preset voltage threshold, the first comparator A1 can output a high-level drive signal to the gate of the transistor Q2, so that the transistor Q2 is turned on, and the surge suppression device 300 is connected to the power grid. On the contrary, when the voltage value of the DC drive signal does not reach the preset voltage threshold, the first comparator A1 can output a low-level drive signal to the gate of the transistor Q1, so that the transistor Q2 is turned off, and the surge suppression device 300 is disconnected from the power grid.

[0116] The driving unit of this embodiment determines whether the voltage value of the DC driving signal reaches a preset voltage threshold. When the voltage value of the DC driving signal reaches the preset voltage threshold, the DC driving signal controls the switch device to be in the on state. When the surge voltage slope reaches the preset slope, the transformer unit outputs a secondary-side sensing signal whose voltage amplitude reaches a preset amplitude calibration value. The driving unit rectifies the secondary-side sensing signal to obtain the DC driving signal whose voltage value reaches the preset voltage threshold. By setting a preset slope, a preset amplitude calibration value, and a preset voltage threshold, this embodiment can more accurately output a DC driving signal that turns the switch device on or off, effectively improving the control accuracy of the switch device, thereby improving the accuracy of surge suppression.

[0117] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the surge suppression circuit of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0118] The present application also proposes a surge suppression method based on the surge suppression circuit of the above embodiment, please refer to Figure 7 , Figure 7 This is a flow chart of an embodiment of a surge suppression method of the present application.

[0119] like Figure 5 As shown, in this embodiment, the surge suppression method includes steps S10 to S20:

[0120] Step S10, determining the surge voltage slope in the power grid.

[0121] Step S20: controlling the on / off state of the switching device according to the surge voltage slope.

[0122] Wherein, when the on-off state of the switch device is the on state, the surge suppression device is connected to the power grid, so that the surge suppression device suppresses the surge voltage in the power grid.

[0123] It should be noted that the execution state of the above surge suppression method may be a surge suppression device integrating the above control module.

[0124] In a specific implementation, the surge suppression device can monitor the voltage in the power grid. When it is detected that there is an instantaneous high voltage that reaches a set threshold at a certain moment, the instantaneous high voltage is determined to be a surge voltage, and the surge voltage slope of the surge voltage at that moment can be determined, and then the surge voltage slope is converted into a corresponding DC voltage, and a DC drive signal with a voltage amplitude of the DC voltage is generated to the control end of the switch device, and the on-off state of the switch device is controlled by the DC drive signal. When the control end of the above-mentioned switch device receives the DC drive signal, it determines whether the DC voltage of the DC drive signal reaches the conduction condition, and closes when the DC voltage reaches the conduction condition, entering the conduction state, and in the conduction state, the loop between the surge suppression device and the power grid port can be turned on, thereby connecting the surge suppression device to the power grid. The surge suppression device can be activated when connected to the power grid, respond to the surge voltage in the power grid, and suppress the surge voltage by guiding the surge voltage to the ground wire or other safe paths to ensure the safety of the device.

[0125] This embodiment determines the surge voltage slope in the power grid; controls the on-off state of the switch device according to the surge voltage slope; and connects the surge suppression device to the power grid when the on-off state of the switch device is the on state, so that the surge suppression device suppresses the surge voltage in the power grid. Since this embodiment controls the surge voltage slope to control the switch device to be in the on state, the surge suppression device is connected to the power grid to suppress the surge voltage, and the surge suppression device is activated by the switch device instead of being directly activated by the surge voltage. Therefore, compared with the prior art, this embodiment has no requirements for the voltage level of the surge suppression device, and the surge suppression device will not be activated only when the surge voltage is high, which effectively improves the surge suppression effect of the surge suppression device.

[0126] The present application also provides an AC / DC converter, wherein the AC / DC converter includes the surge suppression circuit as described in the above embodiment.

[0127] The AC / DC converter provided by the present application includes the surge suppression circuit in the above embodiment, which can solve the technical problem that the surge suppression device is directly activated by the surge voltage in the prior art, and the surge suppression effect is poor when the voltage level of the surge suppression device is high. Compared with the prior art, the beneficial effects of the AC / DC converter provided by the present application are the same as the beneficial effects of the surge suppression circuit provided by the above embodiment, and other technical features of the AC / DC converter are the same as those disclosed in the above embodiment, which will not be repeated here.

[0128] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A surge suppression circuit, characterized in that: The circuit comprises: a control module, a switch device and a surge suppression device; The control module is connected to the control end of the switch device, the first end of the switch device is connected to the first end of the power grid, the second end of the switch device is connected to the first end of the surge suppression device, and the second end of the surge suppression device is connected to the second end of the power grid; The control module is used to detect the slope of the surge voltage in the power grid, and when the slope is greater than a preset threshold, control the switch device to conduct, so as to connect the surge suppression device to the power grid to suppress the surge voltage in the power grid.

2. The surge suppression circuit according to claim 1, characterized in that: The control module is further configured to control the switch device to be disconnected when it is detected that the slope of the surge voltage in the power grid is less than or equal to the preset threshold value, so as to disconnect the surge suppression device from the power grid.

3. The surge suppression circuit according to claim 1, wherein: A first inductor is provided in the power grid, and the control module is connected to two ends of the first inductor; The control module is further used to collect the surge voltage across the first inductor; The control module is further used to determine the surge voltage slope according to the variation amplitude of the surge voltage.

4. The surge suppression circuit according to claim 1, wherein: The control module includes: a transformer unit and a drive unit; The transformer unit is connected to two ends of the first inductor, and the driving unit is connected to the transformer unit and the control end of the switch device respectively; The transformer unit is used to generate a secondary-side sensing signal according to the surge voltage slope, and output the secondary-side sensing signal to the driving unit; The driving unit is used to rectify the secondary side induction signal to obtain a DC driving signal; The driving unit is further used to control the conduction state of the switching device through the DC driving signal.

5. The surge suppression circuit according to claim 4, characterized in that: The driving unit is further used to determine whether the voltage value of the DC driving signal reaches a preset voltage threshold; The driving unit is further configured to control the switching device to be in the on state through the DC driving signal when the voltage value of the DC driving signal reaches the preset voltage threshold.

6. The surge suppression circuit according to claim 5, characterized in that: The transformer unit is further configured to output a secondary-side sensing signal whose voltage amplitude reaches a preset amplitude calibration value when the surge voltage slope reaches a preset slope; The driving unit is used to rectify the secondary-side induction signal to obtain the DC driving signal whose voltage value reaches the preset voltage threshold.

7. The surge suppression circuit according to any one of claims 4 to 6, characterized in that: The transformer unit comprises: a first winding and a second winding; The first winding and the second winding form a transformer structure; The first end of the first winding is connected to the first end of the first inductor, and the second end of the first winding is connected to the second end of the first inductor; A first end of the second winding is connected to a first end of the driving unit, and a second end of the second winding is connected to a second end of the driving unit.

8. The surge suppression circuit according to claim 7, characterized in that: The driving unit includes: a first diode, a first capacitor and a first comparator; The anode of the first diode is connected to the first end of the second winding, the cathode of the first diode is connected to the first end of the first capacitor and the non-inverting input end of the first comparator, the second end of the first capacitor is respectively connected to the second end of the second winding and the first end of the power grid, the inverting input end of the first comparator is connected to a reference source, and the output end of the first comparator is connected to the control end of the switching device.

9. The surge suppression circuit according to claim 8, characterized in that: The power grid is also provided with a first resistor and a second capacitor; The first end of the first resistor is connected to the first end of the first inductor, and the second end of the first resistor is connected to the second end of the surge suppression device; The first end of the second capacitor is connected to the second end of the first inductor, and the second end of the second capacitor is connected to the first end of the switch device.

10. The surge suppression circuit according to claim 9, characterized in that: The switching device is a thyristor; The control end of the thyristor is connected to the output end of the first comparator, the anode of the thyristor is connected to the first end of the surge suppression device, and the cathode of the thyristor is connected to the first end of the power grid.

11. The surge suppression circuit according to claim 10, characterized in that: The switching device is a transistor; The gate of the transistor is connected to the output terminal of the first comparator, the input terminal of the transistor is connected to the first terminal of the surge suppression device, and the output terminal of the transistor is connected to the first terminal of the power grid.

12. A surge suppression method based on the surge suppression circuit according to claims 1 to 11, characterized in that: The method comprises: Determine the surge voltage slope in the power grid; Controlling the on / off state of the switching device according to the surge voltage slope; Wherein, when the on-off state of the switch device is the on state, the surge suppression device is connected to the power grid, so that the surge suppression device suppresses the surge voltage in the power grid.

13. An AC / DC converter, characterized in that: The AC / DC converter comprises the surge suppression circuit according to any one of claims 1 to 11.

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