CN107800117B - Input overvoltage protection circuit with power-on surge current suppression function - Google Patents

Input overvoltage protection circuit with power-on surge current suppression function Download PDF

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Publication number
CN107800117B
CN107800117B CN201711277806.5A CN201711277806A CN107800117B CN 107800117 B CN107800117 B CN 107800117B CN 201711277806 A CN201711277806 A CN 201711277806A CN 107800117 B CN107800117 B CN 107800117B
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circuit
resistor
power
diode
comparator
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CN107800117A (en
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潘永雄
陈林海
李勇
蔡炳利
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Guangdong University of Technology
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Guangdong University of Technology
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)
  • Rectifiers (AREA)

Abstract

The invention discloses an input overvoltage protection circuit with a power-on surge current suppression function, which comprises a power supply circuit, a peak detection circuit, a peak voltage sampling comparison circuit, a power-on instant switching tube current sampling comparison circuit, a bleeder resistor, a low on-resistance switching tube and a reference voltage source, wherein the power-on instant switching tube current sampling comparison circuit is connected with the bleeder resistor; the power supply circuit comprises a first diode, a first capacitor and a voltage limiting bias circuit; the peak detection circuit comprises a second diode and a second capacitor; the peak voltage sampling comparison circuit comprises a first comparator, a first resistor and a second resistor; the current sampling comparison circuit of the power-on instant switching tube comprises a second comparator, a third resistor and a fourth resistor. Therefore, the overvoltage protection action is rapid, and the power-on surge current can be restrained; the overvoltage protection circuit and the power-on surge current suppression circuit are organically combined, the power switch tube and the power supply circuit are shared, the number of elements is small, and the cost is low. Thus, the input overvoltage protection problem is solved, and the power-on surge current can be restrained.

Description

Input overvoltage protection circuit with power-on surge current suppression function
Technical Field
The invention relates to the technical field of switching power supplies, in particular to an input overvoltage protection circuit with a power-on surge current suppression function.
Background
At present, most DC-DC converter control chips provide an overvoltage protection function, and the function can force the converter to stop working when an abnormal high voltage occurs in a power grid, but the overvoltage problem of an input filter capacitor cannot be solved, and the overvoltage problem of an output filter capacitor of an APFC circuit cannot be solved. Therefore, a commercial power detection circuit is added to an individual converter, a relay is triggered to act when commercial power is abnormal, an input loop of the converter is disconnected, but the electromagnetic relay has poor reliability and slow action, an input filter capacitor still bears instantaneous high voltage, and the problem of potential safety hazard is not thoroughly solved.
In addition, the voltage of the filter capacitor end rises from zero at the moment of power-on, and if the filter capacitor end is just near the maximum value of sinusoidal alternating current at the moment of power-on, transient high current up to hundreds of amperes can appear at the moment of power-on, and serious high current impact is caused on a power grid and devices connected in series in an input channel of an AC-DC converter, such as a protective tube, a power frequency rectifier diode, a filter capacitor and the like. At present, in order to restrain the power-on surge current of the switching power supply, a mode of connecting an NTC thermistor, an alternating current zero-crossing trigger or a power resistor in parallel with a relay and the like in series before or after a power frequency rectifying circuit of the converter can be adopted. However, the above measures can control the power-on surge current within a certain range, but have certain drawbacks. For example, the series NTC thermistor has the lowest cost, but during normal operation, the AC input current always flows through the thermistor, so that the NTC resistor consumes large power and is in a high-temperature and high-current state for a long time, and more serious, the NTC resistor is required to be cooled to a normal-temperature state after power is off and then can be electrified, otherwise, the thermistor can lose the electrification surge current inhibition effect, and the reliability of the AC-DC converter is reduced; the AC zero-crossing triggering mode needs a silicon controlled rectifier device, an auxiliary power supply and an AC zero-crossing detection circuit are additionally arranged, the cost is high, and the circuit is complex; the parallel connection mode of the power resistor and the electromagnetic relay can better solve the contradiction between the power-on surge current and the current-limiting resistor power consumption during the normal operation of the converter, but the relay has large attraction current, poor reliability of mechanical contacts and large volume.
Therefore, how to solve the problem of input overvoltage protection and to suppress the power-on surge current is a problem that needs to be solved in the field.
Disclosure of Invention
The invention aims to provide an input overvoltage protection circuit with a power-on surge current suppression function, which is used for suppressing the power-on surge current of a converter while solving the problem of input overvoltage protection.
In order to achieve the above purpose, the invention provides an input overvoltage protection circuit with a power-on surge current suppression function, which comprises a power supply circuit, a peak detection circuit, a peak voltage sampling comparison circuit, a power-on instant switching tube current sampling comparison circuit, a fifth resistor, a low on resistance switching tube and a reference voltage source;
the power supply circuit comprises a first diode, a first capacitor and a voltage limiting bias circuit; the peak detection circuit comprises a second diode and a second capacitor; the peak voltage sampling comparison circuit comprises a first comparator, a first resistor and a second resistor; the current sampling comparison circuit of the power-on instant switching tube comprises a second comparator, a third resistor and a fourth resistor;
the anode of the first diode is connected with the N end of the mains supply, and the cathode of the first diode is respectively connected with the input end of the voltage limiting bias circuit and one end of the first capacitor; the other end of the first capacitor is connected with the negative end of the rectifying circuit; the positive electrode of the second diode is connected with the positive end of the rectifying circuit, and the negative electrode of the second diode is connected with one end of the second capacitor; the other end of the second capacitor is connected with the negative end of the rectifying circuit;
one end of the first resistor is connected with the cathode of the second diode, and the other end of the first resistor is connected with the inverting input end of the first comparator; one end of the second resistor is connected with the negative end of the rectifying circuit, and the other end of the second resistor is connected with the non-inverting input end of the first comparator; one end of the fourth resistor is connected with the negative end of the rectifying circuit, and the other end of the fourth resistor is respectively connected with one end of the third resistor, one end of the fifth resistor and the first end of the low-on-resistance switching tube; the other end of the third resistor is connected with the inverting input end of the second comparator;
the output end of the voltage limiting bias circuit is respectively connected with the output end of the first comparator, the output end of the second comparator, the other end of the fifth resistor and the second end of the low on-resistance switching tube; the third end of the low on-resistance switching tube is connected with the later-stage converter; the input overvoltage protection circuit is connected between the negative end of the rectifying circuit and a primary side common potential reference point of the rear-stage converter;
wherein the fifth resistor is a bleeder resistor; the reference voltage source is used for providing a reference potential for the first comparator and the second comparator, and the first comparator and the second comparator share the same group of reference voltage sources or respectively use independent reference voltage sources.
Optionally, incorporating the peak detection circuit into the power supply circuit to obtain a peak detection power supply circuit; the peak detection power supply circuit comprises the first diode, the second diode, the voltage limiting bias circuit and the first capacitor;
the positive electrode of the first diode is connected with the L end of the mains supply, and the negative electrode of the first diode is respectively connected with the input end of the voltage limiting bias circuit, one end of the first capacitor and the negative electrode of the second diode; the positive pole of the second diode is connected with the N end of the mains supply.
Optionally, the circuit further comprises a sixth resistor, wherein one end of the sixth resistor is respectively connected with the inverting input end of the first comparator and the other end of the first resistor, and the other end of the sixth resistor is connected with the third end of the low-on-resistance switching tube.
Optionally, a seventh resistor is further included in series before or after the second diode.
Optionally, the lightning protection device further comprises a lightning protection device, wherein two ends of the lightning protection device are respectively connected with the first end and the third end of the low on-resistance switching tube.
Optionally, the lightning protection device is a varistor or a discharge tube.
Optionally, the low on-resistance switch tube is a low on-resistance N-channel power MOS tube or a low saturation voltage drop IGBT tube.
Optionally, the voltage limiting bias circuit is a passive circuit or an active circuit.
Optionally, when the later stage converter is the APFC converter, the positive electrode of the first diode is connected to the positive end of the rectifying circuit.
By adopting the technical scheme, when the commercial power has abnormal high voltage, the low-on-resistance switching tube can be turned off, so that the converter is in a suspended state, the voltage withstand requirement on the switching tube in the converter is low, the overvoltage protection action is rapid, and the power-on surge current can be restrained; the overvoltage protection circuit and the power-on surge current suppression circuit are organically combined, the power switch tube and the power supply circuit are shared, the number of elements is small, and the cost is low. Thus, the input overvoltage protection problem is solved, and the power-on surge current can be restrained.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of a specific implementation of an input overvoltage protection circuit with a power-on surge current suppression function according to an embodiment of the present invention;
fig. 2 is another schematic diagram of an input overvoltage protection circuit with a power-on surge current suppression function according to an embodiment of the present invention;
fig. 3 is a schematic diagram of an input overvoltage protection circuit with a power-on surge current suppression function according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a specific application of an input overvoltage protection circuit with a power-on surge current suppression function according to an embodiment of the present invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
Referring to fig. 1, fig. 1 is a schematic diagram of a specific implementation manner of an input overvoltage protection circuit with a power-on surge current suppression function according to an embodiment of the present invention, where the input overvoltage protection circuit 1 includes a power supply circuit 11, a peak detection circuit, a peak voltage sampling comparison circuit 12, a power-on instantaneous switching tube current sampling comparison circuit 13, a fifth resistor 14, a low on resistance switching tube 15 and a reference voltage source;
the power supply circuit 11 includes a first diode D1, a first capacitor C1, and a voltage limiting bias circuit; the peak detection circuit comprises a second diode D2 and a second capacitor C2; the peak voltage sampling comparison circuit 12 includes a first comparator CP1, a first resistor R1, and a second resistor R2; the power-on instant switching tube current sampling comparison circuit 13 comprises a second comparator CP2, a third resistor R3 and a fourth resistor R4;
the anode of the first diode D1 is connected with the N end of the mains supply, and the cathode of the first diode D1 is respectively connected with the input end of the voltage limiting bias circuit and one end of the first capacitor C1; the other end of the first capacitor C1 is connected with the negative end of the rectifying circuit 2; the positive electrode of the second diode D2 is connected with the positive end of the rectifying circuit 2, and the negative electrode of the second diode D2 is connected with one end of the second capacitor C2; the other end of the second capacitor C2 is connected with the negative end of the rectifying circuit 2;
one end of the first resistor R1 is connected with the cathode of the second diode D2, and the other end of the first resistor R1 is connected with the inverting input end of the first comparator CP 1; one end of the second resistor R2 is connected with the negative end of the rectifying circuit 2, and the other end of the second resistor R2 is connected with the non-inverting input end of the first comparator CP 1; one end of the fourth resistor R4 is connected with the negative end of the rectifying circuit 2, and the other end of the fourth resistor R4 is respectively connected with one end of the third resistor R3, one end of the fifth resistor R5 and the first end of the low-on-resistance switching tube 15; the other end of the third resistor R3 is connected with the inverting input end of the second comparator CP 2;
the output end of the voltage limiting bias circuit is respectively connected with the output end of the first comparator CP1, the output end of the second comparator CP2, the other end of the fifth resistor R5 and the second end of the low on-resistance switch tube 15; the third end of the low on-resistance switching tube 15 is connected with the post-stage converter; the input overvoltage protection circuit is connected between a negative terminal A of the rectifying circuit 2 and a common potential reference point B on the primary side of the rear-stage converter 3;
wherein the fifth resistor is a bleeder resistor; the reference voltage source is used for providing a reference potential for the first comparator and the second comparator, and the first comparator and the second comparator share the same group of reference voltage sources or respectively use independent reference voltage sources. Reference voltage source V shown in the figure ref The negative terminal of (2) is connected to the negative terminal A of the rectifying circuit, and the positive terminal is connected to the positive input terminal of the comparator.
It is understood that the low on-resistance switching transistor may be a low on-resistance N-channel power MOS transistor, a low saturation voltage drop IGBT transistor, or other devices having similar functions, which is not limited herein. And the first end of the low on-resistance switch tube can be referred to as a source electrode of the N-channel power MOS tube, the second end can be referred to as a grid electrode of the N-channel power MOS tube, and the third end can be referred to as a drain electrode of the N-channel power MOS tube.
The voltage limiting bias circuit may be a passive circuit or an active circuit. The rectifier circuit may be, but is not limited to, a rectifier bridge.
The latter converter may be specifically an AC-DC converter with various topologies such as flyback, forward, APFC, etc., for example, a DC-DC converter and an APFC converter with Boost topology, and may be connected in parallel to an input filter capacitor 4.
The working process of the input overvoltage protection circuit with the power-on surge current suppression function provided by the embodiment of the invention will be described by taking fig. 1 as an example.
At the moment of power-on, the terminal voltage of the filter capacitor C1 is zero, so that the switch tube 15 is in a cut-off state at the moment of power-on. If the input voltage, the terminal voltage of the input filter capacitor 4, the current of the switch tube 15, the terminal voltage of the switch tube 15, and the reference voltages connected to the non-inverting input terminals of the comparators CP1 and CP2 are V IN 、i DS 、V C3 、V BA 、V ref At the moment of power-up, if the input voltage V IN Larger, because the input filter capacitor 4 is not charged or has small residual charge, the terminal voltage V C3 Small, make the voltage V between BAs BA Larger, when i DS ×R 4 ≥V ref At the time, the comparator CP2 outputs a low level, forcing the current flowing through the switching tube 15 to be limited toThereby suppressing the power-on current. Thus, the resistor R4 and the reference voltage V can be selected ref To limit the maximum current i of the switch tube at the moment of power-on DS . For example, V ref Taken as 1.25V, R4 as 0.13 Ω ->To ensure the normal operation of the converter, the current i is suppressed at the moment of power-up DS Take 1.5 times the maximum operating current peak.
The switch tube 15 is always in a conducting state after being switched on, and the work of the subsequent stage DC-DC converter is not affected because the internal resistance of the switch tube 15 is small.
At the moment of power-up, if the input voltage V IN The switching tube 15 is not conducted, and the input filter capacitor C3 of the converter and the DC-DC converter can obviously not bear the risk of overvoltage; during normal operation, if the input voltage V IN When the abnormal high voltage suddenly appears and is detected by the peak value detection circuit of the input commercial power, the comparator CP1 outputs a low level to force the switching tube 15 to be rapidly turned off, the input high voltage is applied to two ends of the switching tube 15, and the abnormal high voltage is prevented from being applied to the input filter capacitor C3 and the DC-DC converter, so that the input overvoltage protection function is realized. Obviously, the input overvoltage protection voltage value is defined by the ratio of the resistors R1 and R2Determination, i.e. when the input voltage +.>The switching tube 15 is turned off rapidly and in an overvoltage protection state, and the DC-DC converter is not operated. After the overvoltage disappears, the potential of the output end of the input mains peak value detection circuit gradually drops, when the potential of the inverting end of the comparator CP1 is smaller than the potential of the non-inverting end, the comparator CP1 outputs a high level, and the trigger switch tube 15 is conducted, so that the overvoltage recovery operation is realized.
After power failure, AC input voltage V IN No more current flows through the rectifier diode and the filter capacitor C1 discharges, so that the switching tube 15 can be ensured to enter the cut-off state rapidly after the power is off as long as the circuit parameters are properly selected, and the power-on time is short. For example, as long as the magnitude of the bleeder resistor R5 is moderate, the switching tube can be ensured to enter the cut-off state within 100ms after power failure.
In the embodiment, when the commercial power has abnormal high voltage, the low-on-resistance switching tube can be turned off, so that the converter is in a suspended state, the voltage withstand requirement on the switching tube in the converter is low, the overvoltage protection action is rapid, and the power-on surge current can be restrained; the overvoltage protection circuit and the power-on surge current suppression circuit are organically combined, the power switch tube and the power supply circuit are shared, the number of elements is small, and the cost is low. Thus, the input overvoltage protection problem is solved, and the power-on surge current can be restrained.
Example two
Based on the first embodiment, referring to another schematic diagram of the input overvoltage protection circuit with the power-on surge current suppression function shown in fig. 2, the peak detection circuit is integrated into the power supply circuit to obtain a peak detection power supply circuit in this embodiment; the peak detection power supply circuit comprises a first diode D1, a second diode D2, a voltage limiting bias circuit and a first capacitor C1; the anode of the first diode D1 is connected with the L end of the mains supply, and the cathode of the first diode D1 is respectively connected with the input end of the voltage limiting bias circuit, one end of the first capacitor C1 and the cathode of the second diode D2; the positive pole of the second diode D2 is connected with the N end of the mains supply.
That is, the present embodiment is different from the first embodiment in that: two rectifying diodes are provided in the power supply circuit 11, respectively, for D1 and D2, and D1 and D2 constitute full-wave rectification, and the capacity of the filter capacitor C1 can be appropriately increased. Thus, it can be understood that the peak detection circuit is incorporated into the power supply circuit, so that the peak voltage holding capacitance C2 can be saved, so that fewer elements are input to the overvoltage protection circuit, the cost is lower, and the structure is simpler.
Example III
Based on any of the above embodiments, referring to a further schematic diagram of the input overvoltage protection circuit with a power-on surge current suppression function shown in fig. 3, the input overvoltage protection circuit may further include a sixth resistor R6, where one end of the sixth resistor R6 is connected to the inverting input terminal of the first comparator CP1, the other end of the first resistor R1, and the other end is connected to the third terminal of the low on-resistance switching tube 15.
The inverting input end of the comparator CP1 is connected with the third end of the low on-resistance switch tube 15 to form a positive feedback path, thus avoiding the low on-resistance switch tube 15 from inputting the voltage V IN Is positioned at an overpressure protectorAnd the possible on/off phenomenon occurs when the protection point is near. For example, when the input voltage V IN Just equal to overvoltage protection voltage, comparator CP1 outputs low level, causes switch tube Q to close, makes B point potential rise, applies to comparator CP 1's inverting terminal through resistance R6, makes comparator CP 1's inverting terminal potential further rise, even in this way peak detection circuit peak voltage keeps capacitor C2 terminal voltage slightly to drop, also can not make switch tube Q enter the conducting state.
Further, the input overvoltage protection circuit may further include a seventh resistor R7 connected in series before or after the second diode D2. That is, the seventh resistor R7 may have one end connected to the input terminal and the other end connected to the positive electrode of the second diode D2, or may have one end connected to the negative electrode of the second diode D2 and the other end connected to one end of the capacitor C2.
Under the impact of lightning strike voltage, the output voltage of the peak detection circuit is greatly increased, so that after the lightning strike impact voltage pulse, the MOS tube cannot rapidly enter a conducting state, and a current limiting resistor R7 is connected in series before or after the peak detection diode D2 so as to limit the rise of the output voltage of the peak detection circuit.
Further, the input overvoltage protection circuit may further include a lightning protection device, and two ends of the lightning protection device are respectively connected with the first end and the third end of the low on-resistance switching tube. Further, the lightning protection device is a varistor VR or a discharge tube.
For example, as shown in fig. 3, in order to avoid the damage of the MOS transistor caused by the overvoltage of the lightning strike voltage and to provide a lightning strike impulse current path, a varistor VR is connected in parallel between the drain D of the MOS transistor and the negative terminal of the rectifier bridge 2. Thus, under the impact of lightning voltage, the current flowing through the switching tube rises rapidly, when i DS ×R 4 ≥V ref When the voltage of the MOS tube DS is increased rapidly, the comparator CP2 outputs low level, and when V BA When the voltage exceeds the clamping voltage of the piezoresistor VR, the piezoresistor VR is rapidly conducted, and a path is provided for lightning strike impact current.
Example IV
Based on any of the above embodiments, referring to a specific application schematic diagram of the input overvoltage protection circuit with a power-on surge current suppression function shown in fig. 4, the input overvoltage protection circuit may further include a filter capacitor C3, where one end of the filter capacitor C3 is connected to the positive end of the rectifying circuit 2, and the other end is connected to the third end of the low on-resistance switching tube 15;
the rear-stage converter 3 is connected in parallel with two ends of the filter capacitor 4; the latter-stage converter is a DC-DC converter or an APFC converter with a Boost topological structure; when the latter converter is an APFC converter, the positive electrode of the first diode is connected with the positive end of the rectifying circuit.
As shown in fig. 4, the input overvoltage circuit is applied to an APFC converter of a Boost topology. In the figure, the positive electrode of the rectifier diode D1 is connected to the positive end of the rectifier bridge 2, and at this time, the rectifier diode D1 performs the dual functions of isolation and detection, so as to prevent the filter capacitor C1 from discharging through the DC-DC converter. In other embodiments, the positive electrode of the rectifying diode D1 may be connected to the N-terminal or the L-terminal of the ac input line.
In the description, each embodiment is described in a progressive manner, and each embodiment is mainly described by the differences from other embodiments, so that the same similar parts among the embodiments are mutually referred.
The input overvoltage protection circuit with the power-on surge current suppression function provided by the invention is described in detail above. The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.

Claims (7)

1. An input overvoltage protection circuit with a power-on surge current suppression function is characterized by comprising a power supply circuit, a peak detection circuit, a peak voltage sampling comparison circuit, a power-on instant switching tube current sampling comparison circuit, a fifth resistor, a low-on resistance switching tube and a reference voltage source;
the power supply circuit comprises a first diode, a first capacitor and a voltage limiting bias circuit; the peak detection circuit comprises a second diode and a second capacitor; the peak voltage sampling comparison circuit comprises a first comparator, a first resistor and a second resistor; the current sampling comparison circuit of the power-on instant switching tube comprises a second comparator, a third resistor and a fourth resistor;
the anode of the first diode is connected with the N end of the mains supply, and the cathode of the first diode is respectively connected with the input end of the voltage limiting bias circuit and one end of the first capacitor; the other end of the first capacitor is connected with the negative end of the rectifying circuit; the positive electrode of the second diode is connected with the positive end of the rectifying circuit, and the negative electrode of the second diode is connected with one end of the second capacitor; the other end of the second capacitor is connected with the negative end of the rectifying circuit;
one end of the first resistor is connected with the cathode of the second diode, and the other end of the first resistor is connected with the inverting input end of the first comparator; one end of the second resistor is connected with the negative end of the rectifying circuit, and the other end of the second resistor is connected with the non-inverting input end of the first comparator; one end of the fourth resistor is connected with the negative end of the rectifying circuit, and the other end of the fourth resistor is respectively connected with one end of the third resistor, one end of the fifth resistor and the first end of the low-on-resistance switching tube; the other end of the third resistor is connected with the inverting input end of the second comparator;
the output end of the voltage limiting bias circuit is respectively connected with the output end of the first comparator, the output end of the second comparator, the other end of the fifth resistor and the second end of the low on-resistance switching tube; the third end of the low on-resistance switching tube is connected with the post-stage converter; the input overvoltage protection circuit is connected between the negative end of the rectifying circuit and a primary side common potential reference point of the rear-stage converter;
wherein the fifth resistor is a bleeder resistor; the reference voltage source is used for providing a reference potential for the first comparator and the second comparator, and the first comparator and the second comparator share the same group of reference voltage sources or respectively use independent reference voltage sources;
the low-on-resistance switching tube further comprises a sixth resistor, wherein one end of the sixth resistor is respectively connected with the inverting input end of the first comparator and the other end of the first resistor, and the other end of the sixth resistor is connected with the third end of the low-on-resistance switching tube;
and a seventh resistor connected in series before or after the second diode.
2. The input overvoltage protection circuit with a power-on surge current suppression function according to claim 1, wherein the peak detection circuit is incorporated into the power supply circuit to obtain a peak detection power supply circuit; the peak detection power supply circuit comprises the first diode, the second diode, the voltage limiting bias circuit and the first capacitor;
the positive electrode of the first diode is connected with the L end of the mains supply, and the negative electrode of the first diode is respectively connected with the input end of the voltage limiting bias circuit, one end of the first capacitor and the negative electrode of the second diode; the positive pole of the second diode is connected with the N end of the mains supply.
3. The input overvoltage protection circuit with a power-on surge current suppression function according to claim 1, further comprising a lightning protection device, wherein two ends of the lightning protection device are respectively connected with the first end and the third end of the low on-resistance switching tube.
4. An input overvoltage protection circuit with a power-on surge current suppression function according to claim 3, wherein the lightning protection device is a varistor or a discharge tube.
5. The input overvoltage protection circuit with power-on surge current suppression function according to any one of claims 1 to 4, wherein the low on-resistance switching tube is a low on-resistance N-channel power MOS tube or a low saturation voltage drop IGBT tube.
6. The input overvoltage protection circuit with power-on surge current suppression function according to claim 5, wherein the voltage limiting bias circuit is a passive circuit or an active circuit.
7. The input overvoltage protection circuit with power-on surge current suppression function according to claim 5, wherein when the latter stage converter is an APFC converter, the positive electrode of the first diode is connected to the positive terminal of the rectifying circuit.
CN201711277806.5A 2017-12-06 2017-12-06 Input overvoltage protection circuit with power-on surge current suppression function Active CN107800117B (en)

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CN111130089A (en) * 2020-01-07 2020-05-08 惠州拓邦电气技术有限公司 Switching power supply device
CN111446705B (en) * 2020-04-07 2021-12-07 中科新松有限公司 Power-on current-limiting circuit
CN112018743B (en) * 2020-08-25 2022-06-17 中国科学院上海高等研究院 Passive Internet of things chip overvoltage protection circuit and implementation method thereof
CN112968616B (en) * 2021-02-19 2022-02-15 北京泰力控科技有限公司 AC-DC converter and AC-DC conversion system

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CN203415972U (en) * 2013-07-08 2014-01-29 中国航空无线电电子研究所 Input voltage surge suppression circuit
CN105471242A (en) * 2016-01-07 2016-04-06 广东工业大学 Novel power-on surge current suppression circuit
CN205490113U (en) * 2016-01-07 2016-08-17 广东工业大学 Novel last electric surge current suppression circuit

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