Totem pole bridgeless circuit, surge protection method thereof and power supply module

Abstract

The invention discloses a totem-pole bridgeless circuit which comprises a surge protection unit, a first bridge arm unit, a second bridge arm unit and a surge detection protection unit, the surge protection unit is connected with the bridge arm units in parallel, the surge protection unit is provided with a protection input end, the first bridge arm unit is provided with a first bridge arm input end, and the second bridge arm unit is provided with a second bridge arm input end. The first bridge arm unit is provided with a first bridge arm input end, the second bridge arm unit is provided with a second bridge arm input end, the protection input end is connected with the second bridge arm input end, and an input port of the surge detection protection unit is used for inputting an external input alternating current power supply and is connected with the protection input end and the first bridge arm input end; the output end used for outputting the protection control signal is connected with the control end of at least one switching tube in the bridge arm unit, and the protection control signal is used for controlling the switching tube to be in a protection turn-off state so as to prevent surge from being input into the totem-pole bridgeless circuit. The surge residual current sampling device does not need to be connected in series, and the surge reliability of the circuit can be improved.

Description

Technical Field

[0001] The present invention relates to the field of power electronics, and in particular to a totem pole bridgeless circuit and a surge protection method thereof, and a power supply module. Background Art

[0002] With the development of power electronics technology, totem pole bridgeless circuits have been widely used in power factor correction (PFC) circuit technology. However, the surge protection of the input end of this circuit is a difficult problem in the industry. Summary of the invention

[0003] The present invention provides a totem pole bridgeless circuit and a surge protection method and a power supply module, so as to solve the surge protection problem of the AC power input end of the totem pole bridgeless circuit.

[0004] A first aspect of the present invention provides a totem pole bridgeless circuit, the circuit comprising: a surge protection unit, a first bridge arm unit, a second bridge arm unit, and a surge detection protection unit.

[0005] The surge protection unit is connected in parallel with the bridge arm unit, wherein the surge protection unit has a protection input terminal, the first bridge arm unit has a first bridge arm input terminal, the second bridge arm unit has a second bridge arm input terminal, and the protection input terminal is connected to the second bridge arm input terminal.

[0006] The input port of the surge detection protection unit for inputting an external AC power supply is connected to the protection input end and the first bridge arm input end; the output end of the surge detection protection unit for outputting a protection control signal is connected to the control end of at least one switch tube in the bridge arm unit;

[0007] in,

[0008] The protection control signal is used to control the switch tube to be in the protection off state to protect the surge input totem pole bridgeless circuit, so that:

[0009] When there is a positive surge in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the negative half cycle to be turned off and put into the protection shutdown state.

[0010] and / or

[0011] When there is a negative surge in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the positive half cycle to be turned off and put into a protection shutdown state.

[0012] Preferably, the protection control signal is a signal for maintaining the protection duration.

[0013] Preferably, the surge detection protection unit is used to detect a surge signal in the input AC power supply, and extract the surge signal based on the time when the detected surge signal is located, and trigger the generation of a protection control signal based on the extracted surge signal, and trigger the timing of the protection duration maintained by the protection control signal.

[0014] in,

[0015] The protection time is used to control the time the switch tube is in the protection shutdown state.

[0016] Preferably, the surge detection protection unit comprises:

[0017] The surge signal detection circuit is used to detect the surge signal in the input AC power supply.

[0018] The surge signal extraction circuit is used to extract the surge signal at the moment when the surge signal is present.

[0019] A protection control signal circuit is used to generate a protection control signal with a protection duration based on the extracted surge signal,

[0020] in,

[0021] The input port of the surge signal detection circuit is connected to the input AC power supply, the output port of the surge signal detection circuit is connected to the input port of the surge signal extraction circuit, the output port of the surge signal extraction circuit is connected to the input port of the protection control signal circuit, and the output end of the protection control signal circuit is connected to the control end.

[0022] Preferably, the surge protection unit comprises: a surge protection branch circuit in which a first surge protection diode and a second surge protection diode are connected in series;

[0023] Preferably, the first bridge arm unit comprises: a first bridge arm branch; the second bridge arm unit comprises: a second bridge arm branch; the first bridge arm branch and the second bridge arm branch are connected in parallel,

[0024] The first bridge arm branch includes a first switch tube and a second switch tube connected in series, and the second bridge arm branch includes a third switch tube and a fourth switch tube connected in series;

[0025] in,

[0026] A first node where the first surge protection diode and the second surge protection diode are connected in series is connected to the protection input terminal, a second node where the first switch tube and the second switch tube are connected in series is connected to the first bridge arm input terminal, and a fifth node where the third switch tube and the fourth switch tube are connected in series is connected to the second bridge arm input terminal.

[0027] The surge protection branch and the bridge arm branch are connected in parallel between the third node and the fourth node, wherein the potential of the third node is higher than the potential of the fourth node.

[0028] The anode of the first surge protection diode is connected to the cathode of the second surge protection diode, the cathode of the first surge protection diode is connected to the third node, and the anode of the second surge protection diode is connected to the fourth node.

[0029] Preferably, the totem pole bridgeless circuit further comprises: a filter unit connected in series between the input AC power supply and the input port of the surge signal detection circuit, wherein the first output end of the filter unit is connected to the first input end of the surge signal detection circuit and the protection input end, and the second output end of the filter unit is connected to the second input end of the surge signal detection circuit and the first bridge arm input end;

[0030] Preferably, the surge signal detection circuit comprises: a differential circuit for capturing the surge signal, and a detection voltage divider circuit for providing a reference voltage for the differential circuit.

[0031] The differential circuit is connected in series between the first output terminal of the filter unit and the detection output terminal of the surge signal detection circuit.

[0032] One end of the detection voltage divider circuit is connected to a first working voltage end for providing a first working voltage, the other end of the detection voltage divider circuit is connected to a second node, and the voltage divider output end of the detection voltage divider circuit is connected to the detection output end.

[0033] Preferably, an inductor circuit for filtering is also connected in series between the first node and the fifth node;

[0034] The surge signal detection circuit further includes: a clamping circuit for performing voltage clamping on the voltage dividing circuit;

[0035] in,

[0036] The clamping circuit is connected in parallel with the detection voltage divider circuit.

[0037] The detection voltage divider circuit comprises: a first resistor and a second resistor connected in series, and a node where the first resistor and the second resistor are connected in series is connected to a detection output terminal;

[0038] The differential circuit includes a capacitor and a resistor connected in series.

[0039] Preferably, the clamping circuit comprises: a first clamping diode and a second clamping diode connected in series, the anode of the first clamping diode is connected to the cathode of the second clamping diode, the connection is connected to the detection output terminal, the cathode of the first clamping diode is connected to the first working voltage terminal, and the anode of the first clamping diode is connected to the second node;

[0040] Preferably, the surge signal extraction circuit comprises: a first comparison circuit for extracting a positive surge signal, and a second comparison circuit for extracting a negative surge signal.

[0041] in,

[0042] The reference voltage input terminal of the comparison circuit is connected to the second node, and the compared voltage input terminal is connected to the detection output terminal.

[0043] Preferably, the first comparison circuit is a first operational amplifier, and the second comparison circuit is a second operational amplifier.

[0044] in,

[0045] The non-inverting input terminal of the first operational amplifier is connected to the detection output terminal, and the inverting input terminal of the first operational amplifier is connected to the voltage-dividing output terminal of the first voltage-dividing circuit.

[0046] The non-inverting input terminal of the second operational amplifier is connected to the voltage-dividing output terminal of the second voltage-dividing circuit, and the inverting input terminal of the second operational amplifier is connected to the detection output terminal.

[0047] One end of the working power supply of the first operational amplifier and the second operational amplifier is connected to the first working voltage end, and the other end is connected to the second node.

[0048] The first voltage dividing circuit and the second voltage dividing circuit are connected between two ends of the working power supply of the operational amplifier.

[0049] Preferably, the protection control signal includes: a first protection control signal for positive surge protection and a second protection control signal for negative surge protection;

[0050] The protection control signal circuit includes: a first generation and holding circuit for generating a first protection control signal, and a second generation and holding circuit for generating a second protection control signal.

[0051] in,

[0052] The input end of the first generating and holding circuit is connected to the output end of the first operational amplifier, and the output end of the first generating and holding circuit is connected to the control end of the switch tube located between the second node and the third node in the first bridge arm branch and / or the switch tube located between the third node and the fifth node in the second bridge arm branch.

[0053] The input end of the second generation and holding circuit is connected to the output end of the second operational amplifier, and the output end of the second generation and holding circuit is connected to the control end of the switch tube located between the second node and the fourth node in the first bridge arm branch and / or the switch tube located between the fifth node and the fourth node in the second bridge arm branch.

[0054] Preferably, the first generation and holding circuit includes a first peak holding circuit and a first duration holding circuit, the second generation and holding circuit includes a second peak holding circuit and a second duration holding circuit, the peak holding circuit is used to hold the peak value of the surge signal output by the surge signal circuit, and the protection duration holding circuit is used to generate a protection control signal and hold the protection duration,

[0055] in,

[0056] The first time-holding circuit includes a third operational amplifier, the in-phase input terminal of the third operational amplifier is connected to the output terminal of the first operational amplifier through the first peak holding circuit, and is connected to the voltage-dividing output terminal of the third voltage-dividing circuit, and a first feedback branch for controlling the protection time of the first protection control signal is connected between the in-phase input terminal and the output terminal of the third operational amplifier, the inverting input terminal is connected to the voltage-dividing output terminal of the fourth voltage-dividing circuit, the output terminal of the third operational amplifier is connected to the control terminal of the fifth switch tube for controlling the output of the first protection control signal, one end of the working power supply of the third operational amplifier is connected to the first working voltage terminal, and the other end is connected to the second node, the third voltage-dividing circuit and the fourth voltage-dividing circuit are connected between the working power supplies of the third operational amplifier, and the fifth switch tube is connected in series between the control terminal of the controlled switch tube and the second node,

[0057] The second time holding circuit includes a fourth operational amplifier, the non-inverting input terminal of the fourth operational amplifier is connected to the output terminal of the second operational amplifier through the second peak holding circuit, and is connected to the voltage divider output terminal of the fifth voltage divider circuit, and a second feedback branch for controlling the protection time of the second protection control signal is connected between the non-inverting input terminal and the output terminal of the fourth operational amplifier, the inverting input terminal is connected to the voltage divider output terminal of the sixth voltage divider circuit, the output terminal of the fourth operational amplifier is connected to the control terminal of the sixth switch tube for controlling the output of the second protection control signal, one end of the working power supply of the fourth operational amplifier is connected to the second working voltage terminal, and the other end is connected to the fourth node, the fifth voltage divider circuit and the sixth voltage divider circuit are connected between the working power supplies of the fourth operational amplifier, and the sixth switch tube is connected in series between the control terminal of the controlled switch tube and the fourth node.

[0058] Preferably, the first generation and holding circuit includes: a first peak holding circuit and a first time holding circuit, the second generation and holding circuit includes a second peak holding circuit and a second protection time holding circuit, the peak holding circuit is used to hold the surge signal peak value output by the surge signal circuit, and the protection time holding circuit is used to generate a protection control signal and hold the protection time.

[0059] in,

[0060] The first time-holding circuit includes a third operational amplifier, the inverting input terminal of the third operational amplifier is connected to the output terminal of the first operational amplifier through the first peak holding circuit, and is connected to the voltage-dividing output terminal of the fourth voltage-dividing circuit, a first feedback branch for controlling the protection time of the first protection control signal is connected between the non-inverting input terminal of the third operational amplifier and the output terminal of the third operational amplifier, and the non-inverting input terminal is connected to the voltage-dividing output terminal of the third voltage-dividing circuit, the output terminal of the third operational amplifier is connected to the control terminal of the controlled switch tube through a first inverting diode for inverting the output signal, the cathode of the first inverting diode is connected to the output terminal, the anode of the first inverting diode is connected to the control terminal of the controlled switch tube, one end of the working power supply of the third operational amplifier is connected to the first working voltage terminal, and the other end is connected to the second node, the third voltage-dividing circuit and the fourth voltage-dividing circuit are connected between the working power supplies of the third operational amplifier,

[0061] The second protection time holding circuit includes a fourth operational amplifier, the inverting input terminal of the fourth operational amplifier is connected to the output terminal of the second operational amplifier through the second peak holding circuit, and is connected to the voltage divider output terminal of the sixth voltage divider circuit, a second feedback branch for controlling the protection time of the second protection control signal is connected between the non-inverting input terminal of the fourth operational amplifier and the output terminal of the fourth operational amplifier, and the non-inverting input terminal is connected to the voltage divider output terminal of the fifth voltage divider circuit, the output terminal of the fourth operational amplifier is connected to the control terminal of the controlled switch tube through a second inverting diode for inverting the output signal, the cathode of the second inverting diode is connected to the output terminal, the anode of the second inverting diode is connected to the control terminal of the controlled switch tube, one end of the working power supply of the fourth operational amplifier is connected to the second working voltage terminal, and the other end is connected to the fourth node, and the fifth voltage divider circuit and the sixth voltage divider circuit are connected between the working power supplies of the fourth operational amplifier.

[0062] Preferably, the peak holding circuit comprises a diode, the anode of which is connected to the output end of the surge signal extraction circuit.

[0063] Preferably, an isolation circuit for electrical isolation is further provided between the output terminal of the second comparison circuit and the input terminal of the second peak holding circuit.

[0064] Preferably, the feedback branch includes a resistor and a capacitor connected in series.

[0065] Preferably, the protection duration depends on the resistance value and the capacitance value in the feedback branch.

[0066] Preferably, a resistor feedback branch is connected between the output terminal and the in-phase input terminal of the operational amplifier in the generate-hold circuit.

[0067] A second aspect of the present application provides a power supply module, comprising the above-mentioned totem pole bridgeless circuit and an input AC power supply unit for providing power to the totem pole bridgeless circuit.

[0068] A third aspect of the present application provides a surge protection method, the method comprising:

[0069] Detect surge signals in the input AC power supply,

[0070] When a surge signal is detected, a protection control signal is outputted to control the switch tube to be in a protection off state to protect the surge input totem pole bridgeless circuit, so that:

[0071] When there is a positive surge in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the negative half cycle to be turned off and put into the protection shutdown state.

[0072] and / or

[0073] When there is a negative surge in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the positive half cycle to be turned off and put into a protection shutdown state.

[0074] Preferably, the protection control signal is a signal for maintaining the protection duration.

[0075] Preferably, the detecting of a surge signal in an input AC power source comprises:

[0076] Capture surge signals and their timing;

[0077] Preferably, when a surge signal is detected, outputting a protection control signal for controlling the switch tube to be in a protection off state to protect the surge input totem pole bridgeless circuit includes:

[0078] Based on the time at which the detected surge signal occurs, the surge signal at that time is extracted.

[0079] Based on the extracted surge signal, the generation of the protection control signal is triggered, and the timing of the protection time length of the protection control signal is triggered.

[0080] in,

[0081] The protection time is used to control the time the switch tube is in the protection shutdown state;

[0082] The method further comprises:

[0083] A protection control signal is provided to a control terminal of at least one switch tube in the totem pole bridgeless circuit.

[0084] Preferably, providing a protection control signal having a protection duration to a control terminal of at least one switch tube in the totem pole bridgeless circuit comprises:

[0085] When the positive surge signal is located in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube located between the second node and the third node in the first bridge arm branch of the totem pole bridgeless circuit and / or the switch tube located between the third node and the fifth node in the second bridge arm branch.

[0086] When the negative surge signal is located in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube located between the second node and the fourth node in the first bridge arm branch and / or the switch tube located between the fifth node and the fourth node in the second bridge arm branch.

[0087] in,

[0088] The second node is: the serial connection point of the switch tubes in the first bridge arm branch,

[0089] The third node and the fourth node are two ends of the first bridge arm branch and the second bridge arm branch connected in parallel, wherein the potential of the third node is higher than the potential of the fourth node;

[0090] The fifth node is: the serial connection point of the switch tubes in the second bridge arm branch.

[0091] The totem pole bridgeless circuit provided by the present invention captures surge signals in the input AC power supply through a surge detection and protection unit connected between the input AC power supply and the control end of at least one switch tube in the bridge arm unit, and outputs a protection control signal based on the captured surge signal, so that when there is a positive surge in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the negative half cycle to be turned off and put in a protection shutdown state, and / or when there is a negative surge in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the positive half cycle to be turned off and put in a protection shutdown state. The present invention does not need to connect a surge residual current sampling device in series in the totem pole bridgeless circuit, which is conducive to quickly capturing the surge moment, thereby quickly, effectively and controllably turning off the switch tube, improving the circuit surge reliability, and reducing the influence of parasitic parameters on the power circuit, so that the totem pole bridgeless circuit is simple and reliable, and can quickly, effectively and automatically detect and process surge protection, which is conducive to improving the surge protection capability and can predict the surge moment in advance. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1a , Figure 1b A schematic diagram of a totem pole bridgeless circuit in the related art.

[0093] Figure 2 A schematic diagram of a totem pole bridgeless circuit according to an embodiment of the present application.

[0094] Figure 3 A schematic diagram of a surge detection protection unit according to an embodiment of the present application.

[0095] Figure 4 A schematic diagram of a surge signal detection circuit according to an embodiment of the present application.

[0096] Figure 5 A schematic diagram of a surge signal extraction circuit according to an embodiment of the present application.

[0097] Figure 6 A schematic diagram of a protection control signal circuit according to an embodiment of the present application.

[0098] Figure 7 Another schematic diagram of the protection control signal circuit according to an embodiment of the present application.

[0099] Figure 8 It is a waveform diagram of the relevant circuit when the input AC power is in the positive half cycle and there is a forward surge.

[0100] Fig. 9 It is a waveform diagram of the relevant circuit when the input AC power supply is in the negative half cycle and there is a positive surge.

[0101] Fig.10 It is a waveform diagram of the relevant circuit when the input AC power supply is in the positive half cycle and there is a negative surge.

[0102] Fig.11 It is a waveform diagram of the relevant circuit when the input AC power supply is in the negative half cycle and there is a negative surge.

[0103] Fig.12 A schematic diagram of a power module having a totem pole bridgeless circuit according to an embodiment of the present application.

[0104] Fig.13 A schematic flow chart of a surge protection method according to an embodiment of the present application. DETAILED DESCRIPTION

[0105] In order to make the objectives, technical means and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings.

[0106] See also Figure 1a , Figure 1b As shown, Figure 1a , Figure 1bA schematic diagram of a totem pole bridgeless circuit in the related art. The power frequency synchronous tubes SR1 and SR2 are connected in series to form a first bridge arm branch, the switch tubes Q1 and Q2 are connected in series to form a second bridge arm branch, the diodes D1 and D2 are connected in series to form a surge protection branch, and the surge protection branch, the first bridge arm branch, the second bridge arm branch, and the output circuit are connected in parallel. The input AC power port inputs AC power to the totem pole bridgeless circuit through an electromagnetic interference filter (EMI, Electromagnetic interference filter), one terminal of the electromagnetic interference filter port is connected to the series connection of the surge protection branch D1 and D2, and the terminal is also connected to the series connection of Q1 and Q2 in the second bridge arm branch through a filter inductor L1, and the other terminal is connected to the series connection of SR1 and SR2 in the first bridge arm branch.

[0107] In the totem pole bridgeless circuit, when the input AC power supply voltage is in the positive half cycle, if there is a positive surge voltage, the surge residual current can enter the bus capacitor in the load circuit through the surge protection branch. Under the premise that there are certain surge protection devices at the input port of the totem pole bridgeless circuit, the residual current after the surge protection branch will not cause damage to the subsequent devices. However, if there is a negative surge voltage, even if there are surge protection devices at the input port, if the power frequency synchronous tube SR1 is not turned off in time, the residual current after the surge protection branch can easily cause the power frequency synchronous tube SR1 and its short circuit. Similarly, when the input AC power supply voltage is in the negative half cycle, if there is a negative surge voltage, the surge residual current can enter the bus capacitor through the surge protection branch. Under the premise that there is a certain surge protection device at the input port of the totem pole bridgeless circuit, the residual current after the surge protection branch will not cause damage to the subsequent devices. However, when there is a positive surge, although there is a surge protection device at the input port, if the power frequency synchronous tube SR2 is not turned off in time, the residual current after the surge protection branch can easily cause damage to the power frequency synchronous tube SR2 and the devices in its short-circuit path.

[0108] That is to say, when the potential at the power supply terminal L is greater than the potential at the power supply terminal N, there is a positive surge, and there is no need to turn off the lower power frequency synchronous tube SR1. If there is a negative surge, the lower power frequency synchronous tube SR1 must be quickly turned off. Similarly, when the potential at the power supply terminal L is less than the potential at the power supply terminal N, there is a negative surge, and there is no need to turn off the upper power frequency synchronous tube SR2. If there is a positive surge, the upper power frequency synchronous tube SR2 must be quickly turned off. Based on this, the surge residual current flowing through the subsequent circuit is usually sampled, and once the surge residual current exceeds a certain value, the corresponding power frequency synchronous tube is turned off.

[0109] The applicant found that in the related art, the current of the surge residual current is usually detected only after reaching a certain value before the corresponding switch tube is turned off. Since the previous stage circuit of the subsequent stage circuit is an EMI circuit, there must be a relatively large X capacitor in the EMI circuit. If the surge arrives at a time close to the peak point of the input voltage, such as a 90° or 270° phase, and the surge phase is opposite to the current input voltage phase, it is necessary to wait until the X capacitors of the previous stage EMI circuit are discharged and the input voltage is reversed, and then the residual current appears in the totem pole bridgeless circuit. Only then can the residual current be detected. Although the current detection threshold set may be relatively small, the residual current at this moment is already very large. Coupled with the delay of the control circuit used to control the switch tube, the large residual current can easily cause damage to the power frequency synchronous tube.

[0110] In view of this, the present application provides a totem pole bridgeless circuit, which can quickly detect a surge signal without waiting for the X capacitor to be discharged or the voltage to be reversed. Furthermore, the detected surge signal is maintained for a certain period of time to turn off the target switch tube in advance and quickly, thereby greatly improving the surge protection capability and enhancing the reliability of the power supply.

[0111] See also Figure 2 As shown, Figure 2 This is a schematic diagram of a totem pole bridgeless circuit according to an embodiment of the present application. The circuit includes: a surge protection unit, a bridge arm unit having at least one switch tube, and a surge detection protection unit.

[0112] The surge protection unit is connected in parallel with the bridge arm unit, the surge protection unit has a protection input end, the first bridge arm unit has a first bridge arm input end, the second bridge arm unit has a second bridge arm input end, and the protection input end is connected to the second bridge arm input end.

[0113] The input port of the surge detection protection unit is used to input an input AC power supply from the outside, and the output end of the surge detection protection unit is used to output a protection control signal, which is connected to the control end of at least one switch tube in the bridge arm unit, wherein the input port of the surge detection protection unit is connected to the protection input end and the first bridge arm input end,

[0114] The surge detection protection unit is used to detect the surge signal in the input AC power supply, and extract the surge signal based on the time when the surge signal is detected, and trigger the generation of the protection control signal based on the extracted surge signal, and trigger the timing of the protection time length maintained by the protection control signal, wherein,

[0115] The protection control signal is used to control the switch tube to be in a protection shutdown state to protect against surges, and the protection duration is used to control the duration that the switch tube is in the protection shutdown state.

[0116] For example,

[0117] The surge protection unit comprises: a surge protection branch in which a first surge protection diode and a second surge protection diode are connected in series, a first node where the first surge protection diode and the second surge protection diode are connected in series is connected to a protection input terminal, an anode of the first surge protection diode is connected to a cathode of the second surge protection diode,

[0118] The first bridge arm unit includes: a first bridge arm branch; the second bridge arm unit includes a second bridge arm branch, the first bridge arm branch and the second bridge arm branch are connected in parallel, the first bridge arm branch includes a first switch tube and a second switch tube connected in series, and the second bridge arm branch includes a third switch tube and a fourth switch tube connected in series; the second node where the first switch tube and the second switch tube are connected in series is connected to the first bridge arm input end, and the fifth node where the third switch tube and the fourth switch tube are connected in series is connected to the second bridge arm input end.

[0119] The surge protection branch and the bridge arm branch are connected in parallel between the third node and the fourth node, wherein the potential of the third node is higher than the potential of the fourth node.

[0120] A cathode of the first surge protection diode is connected to the third node, and an anode of the second surge protection diode is connected to the fourth node.

[0121] The totem pole bridgeless circuit also includes: a filtering unit, such as an EMI unit, connected in series between the input power port and the input port of the surge detection protection unit, wherein the first output end of the filtering unit is connected to the first input end of the surge detection protection unit, and the second output end of the filtering unit is connected to the second input end of the surge detection protection unit.

[0122] Optionally, an inductor circuit for filtering is connected in series between the first node and the fifth node.

[0123] As an example, see Figure 3 As shown, Figure 3 A schematic diagram of a surge detection protection unit according to an embodiment of the present application includes:

[0124] The surge signal detection circuit is used to detect the surge signal in the input AC power supply.

[0125] The surge signal extraction circuit is used to extract the surge signal at the moment when the surge signal is present.

[0126] A protection control signal circuit is used to generate a protection control signal with a protection duration based on the extracted surge signal,

[0127] in,

[0128] The input port of the surge signal detection circuit is connected to the input power port, the output port of the surge signal detection circuit is connected to the input port of the surge signal extraction circuit, the output port of the surge signal extraction circuit is connected to the input port of the protection control signal circuit, and the output end of the protection control signal circuit is connected to the control end.

[0129] See also Figure 4 As shown, Figure 4 The figure is a schematic diagram of a surge signal detection circuit. The surge signal detection circuit includes: a differential circuit for capturing a surge signal, and a detection voltage divider circuit for providing a reference voltage for the differential circuit.

[0130] One end of the detection voltage divider circuit is connected to a first working voltage end for providing a first working voltage, the other end of the detection voltage divider circuit is connected to a second node, and a voltage divider output end of the detection voltage divider circuit is connected to a detection output end of a surge signal detection circuit.

[0131] The differential circuit is connected in series between the first input end of the surge detection protection unit, that is, the first input end of the surge signal detection circuit and the detection output end, that is, one end of the differential circuit is connected to the first input end of the surge detection protection unit, and the other end of the differential circuit is connected to the detection output end; when the totem pole bridgeless circuit also includes an EMI circuit, the differential circuit is connected in series between the first output end of the EMI circuit and the detection output end, that is, one end of the differential circuit is connected to the first output end of the EMI circuit, and the other end of the differential circuit is connected to the detection output end. Among them, the detection output end and the terminal connected to the second node in the surge signal detection circuit form the output port of the surge signal detection circuit.

[0132] The surge signal detection circuit also includes: a clamping circuit for clamping the voltage of the voltage divider circuit; the clamping circuit is connected in parallel with the detection voltage divider circuit.

[0133] For example, the differential circuit includes: a capacitor and a resistor connected in series; the detection voltage divider circuit includes: a first resistor and a second resistor connected in series, and the node where the first resistor and the second resistor are connected in series is connected to the detection output terminal; the clamping circuit includes: a first clamping diode and a second clamping diode connected in series, the anode of the first clamping diode is connected to the cathode of the second clamping diode, the connection is connected to the detection output terminal, the cathode of the first clamping diode is connected to the first working voltage terminal, and the anode of the first clamping diode is connected to the second input terminal of the surge detection protection unit, that is, the second input terminal of the surge signal detection circuit (the second node in the figure); the first working voltage is VCC1.

[0134] The first input terminal and the second input terminal of the surge detection protection unit form an input port of the surge detection protection unit.

[0135] See also Figure 5 As shown, Figure 5 A schematic diagram of a surge signal extraction circuit. The surge signal extraction circuit includes: a first comparison circuit for extracting a positive surge signal, and a second comparison circuit for extracting a negative surge signal, wherein the reference voltage input terminal of the comparison circuit is connected to the second node, so that the potential of the second node is used as the reference potential of the comparison circuit, and the compared voltage input terminal is connected to the detection output terminal, so that the surge signal is input to the comparison circuit for extraction, and when the input surge signal is greater than the reference voltage of the comparison circuit, the comparison circuit outputs the input surge signal, thereby obtaining the extracted surge signal. Among them, in the surge signal extraction circuit, the terminal connected to the detection output terminal and the second node forms the input port of the surge signal extraction circuit.

[0136] As an example, the first comparison circuit is a non-inverting comparator, including a first operational amplifier, and the second comparison circuit is an inverting comparator, including a second operational amplifier, wherein the non-inverting input terminal of the first operational amplifier is connected to the detection output terminal, the inverting input terminal of the first operational amplifier is connected to the voltage divider output terminal of the first voltage divider circuit, the non-inverting input terminal of the second operational amplifier is connected to the voltage divider output terminal of the second voltage divider circuit, the inverting input terminal of the second operational amplifier is connected to the detection output terminal, one end of the working power supply of the first operational amplifier and the second operational amplifier is connected to the first working voltage terminal, and the other end is connected to the second node, and the first voltage divider circuit and the second voltage divider circuit are connected between the two ends of the working power supply of the operational amplifier. Wherein, the output terminal of the first operational amplifier and the output terminal of the second operational amplifier form the output port of the surge signal extraction circuit.

[0137] Since the first comparison circuit outputs a positive surge signal and the second comparison circuit outputs a negative surge signal, the protection control signal includes: a first protection control signal for positive surge protection and a second protection control signal for negative surge protection.

[0138] See also Figure 6 As shown, Figure 6 The protection control signal circuit includes: a first generation and holding circuit for generating a first protection control signal, and a second generation and holding circuit for generating a second protection control signal.

[0139] in,

[0140] The input end of the first generating and holding circuit is connected to the output end of the first operational amplifier, and the output end of the first generating and holding circuit is connected to the control end of the switch tube located between the second node and the third node in the first bridge arm branch and / or the switch tube located between the third node and the fifth node in the second bridge arm branch. Figure 2The upper middle switch tubes, namely the first switch tube and the third switch tube, wherein the fifth node is the serial connection point of the switch tubes in series in the second bridge arm branch,

[0141] The input end of the second generation and holding circuit is connected to the output end of the second operational amplifier, and the output end of the second generation and holding circuit is connected to the control end of the switch tube located between the second node and the fourth node in the first bridge arm branch and / or the switch tube located between the fifth node and the fourth node in the second bridge arm branch. Figure 2 The middle and lower switch tubes are the second switch tube and the fourth switch tube. The terminal connected to the output end of the first operational amplifier and the terminal connected to the output end of the second operational amplifier in the protection control signal circuit form the input port of the protection control signal circuit.

[0142] For example, the first generation and holding circuit includes: a first peak holding circuit and a first time holding circuit, and the second generation and holding circuit includes: a second peak holding circuit and a second time holding circuit, wherein the peak holding circuit is used to hold the peak value of the surge signal output by the surge signal circuit, and the protection time holding circuit is used to generate a protection control signal and hold the protection time.

[0143] in,

[0144] The peak holding circuit comprises a diode, the anode of which is connected to the output end of the surge signal extraction circuit, so as to hold the peak value by unidirectional conduction of the diode.

[0145] The first time-holding circuit includes a third operational amplifier, the non-inverting input terminal of the third operational amplifier is connected to the output terminal of the first operational amplifier through the first peak holding circuit, and is connected to the voltage-dividing output terminal of the third voltage-dividing circuit to provide a reference voltage to the non-inverting input terminal of the third operational amplifier, and a first feedback branch for controlling the protection time of the first protection control signal is connected between the non-inverting input terminal and the output terminal of the third operational amplifier, the inverting input terminal is connected to the voltage-dividing output terminal of the fourth voltage-dividing circuit to provide a reference voltage to the inverting input terminal of the third operational amplifier, the output terminal of the third operational amplifier is connected to the control terminal of the fifth switch tube for controlling the output of the first protection control signal, one end of the working power supply of the third operational amplifier is connected to the first working voltage terminal, and the other end is connected to the second node, the third voltage-dividing circuit and the fourth voltage-dividing circuit are connected between the working power supplies of the third operational amplifier, and the fifth switch tube is connected in series between the control terminal of the controlled switch tube and the second node,

[0146] The second time-holding circuit includes a fourth operational amplifier, the in-phase input terminal of the fourth operational amplifier is connected to the output terminal of the second operational amplifier through the second peak holding circuit, and is connected to the voltage-dividing output terminal of the fifth voltage-dividing circuit to provide a reference voltage to the in-phase input terminal of the fourth operational amplifier, and a second feedback branch for controlling the protection time of the second protection control signal is connected between the in-phase input terminal and the output terminal of the fourth operational amplifier, the inverting input terminal is connected to the voltage-dividing output terminal of the sixth voltage-dividing circuit to provide a reference voltage to the inverting input terminal of the fourth operational amplifier, the output terminal of the fourth operational amplifier is connected to the control terminal of the sixth switch tube for controlling the output of the second protection control signal, one end of the working power supply of the fourth operational amplifier is connected to the second working voltage terminal, and the other end is connected to the fourth node, the fifth voltage-dividing circuit and the sixth voltage-dividing circuit are connected between the working power supplies of the fourth operational amplifier, and the sixth switch tube is connected in series between the control terminal of the controlled switch tube and the fourth node. As another example, see Figure 7 As shown, Figure 7 Another schematic diagram of the protection control signal circuit. Figure 6 The difference is that the extracted surge signal is input to the inverting input terminal of the operational amplifier, and the output terminal of the operational amplifier outputs the protection control signal through an inverting diode.

[0147] Specifically, the inverting input terminal of the third operational amplifier is connected to the output terminal of the first operational amplifier through the first peak holding circuit, and is connected to the voltage-dividing output terminal of the fourth voltage-dividing circuit. A first feedback branch for controlling the protection duration of the first protection control signal is connected between the non-inverting input terminal of the third operational amplifier and the output terminal of the third operational amplifier, and the non-inverting input terminal is connected to the voltage-dividing output terminal of the third voltage-dividing circuit. The output terminal of the third operational amplifier is connected to the control terminal of the controlled switch tube through a first inverting diode for inverting the output signal. The cathode of the first inverting diode is connected to the output terminal, and the anode of the first inverting diode is connected to the control terminal of the controlled switch tube. One end of the working power supply of the third operational amplifier is connected to the first working voltage terminal, and the other end is connected to the second node. The third voltage-dividing circuit and the fourth voltage-dividing circuit are connected between the working power supplies of the third operational amplifier.

[0148] The inverting input terminal of the fourth operational amplifier is connected to the output terminal of the second operational amplifier through the second peak holding circuit, and is connected to the voltage-dividing output terminal of the sixth voltage-dividing circuit. A second feedback branch for controlling the protection duration of the second protection control signal is connected between the non-inverting input terminal of the fourth operational amplifier and the output terminal of the fourth operational amplifier, and the non-inverting input terminal is connected to the voltage-dividing output terminal of the fifth voltage-dividing circuit. The output terminal of the fourth operational amplifier is connected to the control terminal of the controlled switch tube through a second inverting diode for inverting the output signal. The cathode of the second inverting diode is connected to the output terminal, and the anode of the second inverting diode is connected to the control terminal of the controlled switch tube. One end of the working power supply of the fourth operational amplifier is connected to the second working voltage terminal, and the other end is connected to the fourth node. The fifth voltage-dividing circuit and the sixth voltage-dividing circuit are connected between the working power supplies of the fourth operational amplifier. Figure 6 , Figure 7 In the protection control signal circuit, the working power supply of the fourth operational amplifier is the second working voltage VCC2. Since the working power supply of the fourth operational amplifier is connected to the fourth node and does not have a common node with the working power supply of the second operational amplifier, an isolation circuit for electrical isolation is also included between the output end of the second comparison circuit and the input end of the second peak holding circuit, for example, an isolation diode, an isolation chip, an optocoupler, etc.

[0149] The feedback branch includes a resistor and a capacitor connected in series, and the protection duration depends on the resistance value and the capacitance value of the resistor in the feedback branch. The resistance value and the capacitance value between the first feedback branch and the second feedback branch can be the same or different.

[0150] In addition, a resistor feedback branch may be connected between the output terminal and the in-phase input terminal of the operational amplifier so that the operational amplifier has a proportional amplification function, that is, the input signal is amplified proportionally, and the amplification ratio is related to the resistance value in the resistor feedback branch and the resistance value of the resistor connected to the in-phase input terminal. Moreover, since the operational amplifier has a positive feedback branch, circuit oscillation can be avoided in this way.

[0151] The working process of the totem pole bridgeless circuit of the embodiment of the present application is explained below in conjunction with the circuit waveform diagram.

[0152] See also Figure 8 As shown, Figure 8 It is a waveform diagram of the relevant circuit when the input AC power is in the positive half cycle and there is a forward surge.

[0153] When the input AC power is in the positive half cycle and there is a positive surge, the differential circuit in the surge signal detection circuit forms a differential signal, so that the surge signal is detected. The differential signal is superimposed on the divided voltage of the detection voltage divider circuit in the surge signal detection circuit, such as Figure 8 The surge signal detection circuit outputs the signal waveform.

[0154] The signal output by the surge signal detection circuit is input to the surge signal extraction circuit. Since the in-phase input voltage of the first operational amplifier is greater than the inverting reference voltage of the first comparison circuit at this time, the first comparison circuit outputs a voltage greater than the reference voltage in its input voltage, which is equivalent to extracting a positive surge signal. Figure 8 The surge signal extraction circuit outputs a signal waveform, and since the inverting input voltage of the second operational amplifier is greater than the in-phase reference voltage of the second comparison circuit at this time, the second operational amplifier outputs a zero-value voltage.

[0155] After the extracted surge signal is input into the protection control signal circuit, the first generation and holding circuit in the protection control signal circuit outputs the first protection control signal due to the input of the extracted positive surge signal. Since there is a first feedback branch between the output end and the non-inverting input end of the third operational amplifier, the output first protection control signal simultaneously triggers the output end of the third amplifier operational amplifier to charge and discharge through the first feedback branch until the voltage at the non-inverting input end of the third operational amplifier reaches the divided voltage of the third voltage divider circuit, thereby maintaining the first protection control signal; at this time, the non-inverting input end of the third operational amplifier outputs a zero-value voltage at the output end of the third operational amplifier because the extracted positive surge signal is zero, thereby ending the output of the first protection control signal; when the output end of the third operational amplifier outputs a zero-value voltage, the output end of the third operational amplifier charges and discharges the capacitor in the first feedback branch until the voltage at the inverting input end of the third operational amplifier is reached, and at this time, the output end of the third operational amplifier outputs a zero-value voltage. The holding time of the first protection control signal depends on the charge and discharge time, that is, the width of the first protection control signal depends on the discharge time, for example, the discharge time corresponding to the discharge waveform in the input waveform of the third operational amplifier.

[0156] For example, Figure 8The input waveform and output waveform of the third operational amplifier in the waveform diagram, the steady-state voltage value of the third operational amplifier input is the voltage-dividing value input by the third voltage-dividing circuit and the fourth voltage-dividing circuit; when the output signal of the surge extraction circuit arrives, the voltage at the in-phase input terminal of the third operational amplifier is greater than the voltage at the inverting input terminal, and the third operational amplifier is equivalent to a comparator at this time, thereby outputting a high level; at the moment when the third operational amplifier outputs a high level, the capacitor in the feedback branch will cause the voltage at the in-phase input terminal to rise rapidly, and the input waveform of the third operational amplifier increases by a step from the steady-state voltage, wherein the feedback capacitor plays the role of blocking DC and passing AC, which can be understood The solution is the high-frequency response of the capacitor; then the left end of the capacitor begins to discharge, and the non-inverting input voltage of the third operational amplifier begins to gradually decrease, as shown in the discharge waveform in the input waveform of the third operational amplifier in Figure 8. During the discharge process, the output of the third operational amplifier maintains a high level until the non-inverting terminal voltage drops to be equal to the inverting input voltage, that is, it reaches a steady-state voltage. At this time, the output of the third operational amplifier is at a low level; at the moment when the output of the third operational amplifier is at a low level, the potential on the right side of the capacitor becomes low, and due to the DC-isolating and AC-passing effect of the capacitor, the potential on the left side of the capacitor will also immediately become low. In this way, the voltage on the non-inverting input of the third operational amplifier will rapidly decrease, as shown in Figure 8. Figure 8 The input waveform of the third operational amplifier drops from a steady-state voltage step, making the circuit stable and oscillating; due to the existence of the third voltage divider circuit, the voltage of the capacitor will not always be zero, but will gradually increase with the charging voltage until it finally returns to the previous steady-state voltage, as shown in the charging waveform of the input waveform of the third operational amplifier. In summary, the capacitor is equivalent to providing high-frequency positive feedback, which can store energy to maintain the output voltage and quickly provide a positive feedback channel.

[0157] Since the first switch tube is in the off state when the input AC power is in the positive half cycle, at this time, even if the first protection control signal pulls down the driving level of the control terminal of the first switch tube, it does not affect the working state of the first switch tube. Although the second switch tube is in the on state, since the first protection control signal is not connected to the second switch tube, it does not affect the working state of the second switch tube. The positive surge flows back to the input power supply through the diode, output circuit, and second switch tube in the surge protection branch. Figure 1a As shown in the figure above.

[0158] See also Fig. 9 As shown, Fig. 9 This is a waveform diagram of the relevant circuit when the input AC power supply is in the negative half cycle and there is a positive surge. The working process of the surge signal detection circuit, surge signal extraction circuit, and protection control signal circuit is similar to Figure 8The process is the same, except that, since the first protection control signal appears when the first switch tube is in the on state, at this time, the driving level of the control end of the first switch tube is pulled down due to the first protection control signal, so that the first switch tube is in an instantaneous protection off state during the output of the first protection control signal, so that the forward surge will not flow into the totem pole bridgeless circuit.

[0159] See also Fig.10 As shown, Fig.10 It is a waveform diagram of the relevant circuit when the input AC power supply is in the positive half cycle and there is a negative surge.

[0160] When the input AC power supply is in the positive half cycle and there is a negative surge, the differential circuit in the surge signal detection circuit forms a differential signal, so that the surge signal is detected. The differential signal is superimposed on the divided voltage of the detection voltage divider circuit in the surge signal detection circuit, such as Figure 8 The surge signal detection circuit outputs the signal waveform.

[0161] The signal output by the surge signal detection circuit is input to the surge signal extraction circuit. Since the input voltage of the surge signal extraction circuit is less than the in-phase reference voltage of the second comparison circuit, the second comparison circuit outputs a high level, which is equivalent to extracting a negative surge signal. Fig.10 The surge signal extraction circuit outputs a signal waveform, and since the input voltage of the first operational amplifier is greater than the inverting reference voltage of the first operational amplifier at this time, the first operational amplifier outputs a zero-value voltage.

[0162] After the extracted surge signal is input into the protection control signal circuit, the second generation and holding circuit in the protection control signal circuit outputs the second protection control signal due to the input of the extracted negative surge signal. Since there is a second feedback branch between the output end and the in-phase input end of the fourth operational amplifier, the output second protection control signal simultaneously triggers the output end of the fourth amplifier operational amplifier to charge and discharge through the second feedback branch until the voltage of the in-phase input end of the fourth operational amplifier reaches the divided voltage of the fifth voltage divider circuit, so that the second protection control signal is maintained; at this time, the in-phase input end of the fourth operational amplifier outputs a zero-value voltage due to the extracted negative surge signal being zero, thereby ending the output of the second protection control signal; when the output end of the fourth operational amplifier outputs a zero-value voltage, the output end of the fourth operational amplifier charges and discharges the capacitor in the second feedback branch until the voltage of the inverting input end of the fourth operational amplifier is reached, and at this time, the output end of the fourth operational amplifier outputs a zero-value voltage. Among them, the holding time of the second protection control signal depends on the discharge time, that is, the width of the second protection control signal depends on the discharge time.

[0163] The formation process of the input waveform and the output waveform of the fourth operational amplifier is the same as that of the third operational amplifier, and will not be repeated herein.

[0164] Since the first switch tube is in the off state when the input AC power supply is in the positive half cycle, at this time, the first protection control signal does not affect the working state of the first switch tube. Since the second switch tube is in the on state, the second protection control signal causes the driving level of the control end of the second switch tube to be lowered, so that the second switch tube is in an instantaneous protection off state during the output of the second protection control signal. In this way, the negative surge will not flow into the totem pole bridgeless circuit.

[0165] See also Fig.11 As shown, Fig.11 This is a waveform diagram of the relevant circuit when the input AC power is in the negative half cycle and there is a negative surge. The working process of the surge signal detection circuit, surge signal extraction circuit, and protection control signal circuit is similar to Fig.10 The process is the same, except that, since the second switch tube is in the off state when the input AC power supply is in the negative half cycle, at this time, even if the second protection control signal pulls down the driving level of the control end of the second switch tube, it does not affect the working state of the second switch tube. Although the first switch tube is in the on state, since the second protection control signal is not connected to the control end of the first switch tube, it does not affect the working state of the first switch tube. The negative surge flows back to the input power supply through the diode, the output circuit, and the second switch tube in the surge protection branch. Figure 1b As shown in the figure above.

[0166] The control of the third switch tube is the same as that of the first switch tube, and the control of the fourth switch tube is the same as that of the second switch tube.

[0167] The totem pole bridgeless circuit of the embodiment of the present application does not need to be connected in series with any current sampling device, does not increase the loss of the original power circuit, and can quickly capture the surge signal and its time through the differential circuit in the surge signal detection circuit. In this way, the arrival of the surge signal can be captured in advance without waiting for the X capacitor to be discharged and the voltage to be reversed. By protecting the first feedback branch and the second feedback branch in the control signal circuit, the protection time of the switch tube can be freely selected. For example, the protection time can be selected according to the protection level required by the totem pole bridgeless circuit, which is conducive to the protection of surges of different wavelengths, such as short wave surges and long wave surges.

[0168] See also Fig.12 As shown, Fig.12A schematic diagram of a power module having a totem pole bridgeless circuit according to an embodiment of the present application. The power module includes: an input AC power supply unit, an EMI unit, a surge protection unit, a first bridge arm unit, a second bridge arm unit, and an output unit connected in sequence, and the totem pole bridgeless circuit module also includes: a surge detection protection unit, a first input end of the surge detection protection unit is connected to a first output end of the EMI unit, a second input end of the surge detection protection unit is connected to a second output end of the EMI unit, and a control output end of the surge detection protection unit for outputting a protection control signal is respectively connected to a control end of a controlled target switch tube.

[0169] See also Fig.13 As shown, Fig.13 A schematic diagram of a surge protection method according to an embodiment of the present application is provided, and the method includes:

[0170] Detect surge signals in the input AC power supply,

[0171] When a surge signal is detected, a protection control signal is outputted to control the switch tube to be in a protection off state to protect the surge input totem pole bridgeless circuit, so that:

[0172] When there is a positive surge in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the negative half cycle to be turned off and put into the protection shutdown state.

[0173] and / or

[0174] When there is a negative surge in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the positive half cycle to be turned off and put into a protection shutdown state.

[0175] As an example, the protection control signal is a signal for maintaining the protection duration.

[0176] The method of detecting a surge signal in an input AC power supply comprises:

[0177] Capture surge signals and their timing,

[0178] The method of outputting a protection control signal for controlling the switch tube to be in a protection off state to protect the surge input totem pole bridgeless circuit when a surge signal is detected includes:

[0179] Based on the time at which the detected surge signal occurs, the surge signal at that time is extracted.

[0180] Based on the extracted surge signal, the generation of the protection control signal is triggered, and the timing of the protection time length of the protection control signal is triggered.

[0181] in,

[0182] The protection time is used to control the time the switch tube is in the protection shutdown state;

[0183] The method further comprises:

[0184] A protection control signal with a protection duration is provided to the control end of at least one switch tube in the totem pole bridgeless circuit.

[0185] As an example, the above method can be implemented in the form of a computer program, the computer program is stored in a memory, and the processor is configured to execute the computer program to implement the steps of the surge protection method of the present application.

[0186] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0187] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0188] An embodiment of the present invention further provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the steps of the surge protection method of the present application are implemented.

[0189] As for the apparatus / network-side device / storage medium embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0190] In this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. All connected in this application are electrically connected.

[0191] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A totem pole bridgeless circuit, characterized in that: The circuit includes: a surge protection unit, a first bridge arm unit, a second bridge arm unit, and a surge detection protection unit. The surge protection unit is connected in parallel with the bridge arm unit, wherein the surge protection unit has a protection input terminal, the first bridge arm unit has a first bridge arm input terminal, the second bridge arm unit has a second bridge arm input terminal, and the protection input terminal is connected to the second bridge arm input terminal. The input port of the surge detection protection unit for inputting an external AC power supply is connected to the protection input end and the first bridge arm input end; the output end of the surge detection protection unit for outputting a protection control signal is connected to the control end of at least one switch tube in the bridge arm unit; in, The protection control signal is used to control the switch tube to be in the protection off state to protect the surge input totem pole bridgeless circuit, so that: When there is a positive surge in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the negative half cycle to be turned off and put into the protection shutdown state. and / or When there is a negative surge in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the positive half cycle to be turned off and put into a protection shutdown state.

2. The totem pole bridgeless circuit as claimed in claim 1, characterized in that: The protection control signal is a signal for maintaining the protection duration. The surge detection protection unit is used to detect the surge signal in the input AC power supply, extract the surge signal based on the time when the surge signal is detected, and trigger the generation of the protection control signal based on the extracted surge signal, and trigger the timing of the protection time length maintained by the protection control signal. in, The protection time is used to control the time the switch tube is in the protection shutdown state.

3. The totem pole bridgeless circuit as claimed in claim 2, characterized in that: The surge detection protection unit comprises: The surge signal detection circuit is used to detect the surge signal in the input AC power supply. The surge signal extraction circuit is used to extract the surge signal at the moment when the surge signal is present. A protection control signal circuit is used to generate a protection control signal with a protection duration based on the extracted surge signal, in, The input port of the surge signal detection circuit is connected to the input AC power supply, the output port of the surge signal detection circuit is connected to the input port of the surge signal extraction circuit, the output port of the surge signal extraction circuit is connected to the input port of the protection control signal circuit, and the output end of the protection control signal circuit is connected to the control end.

4. The totem pole bridgeless circuit as claimed in claim 3, characterized in that: The surge protection unit comprises: a surge protection branch circuit in which a first surge protection diode and a second surge protection diode are connected in series; The first bridge arm unit includes: a first bridge arm branch; the second bridge arm unit includes: a second bridge arm branch; the first bridge arm branch and the second bridge arm branch are connected in parallel, The first bridge arm branch includes a first switch tube and a second switch tube connected in series, and the second bridge arm branch includes a third switch tube and a fourth switch tube connected in series; in, A first node where the first surge protection diode and the second surge protection diode are connected in series is connected to the protection input terminal, a second node where the first switch tube and the second switch tube are connected in series is connected to the first bridge arm input terminal, and a fifth node where the third switch tube and the fourth switch tube are connected in series is connected to the second bridge arm input terminal. The surge protection branch and the bridge arm branch are connected in parallel between the third node and the fourth node, wherein the potential of the third node is higher than the potential of the fourth node. The anode of the first surge protection diode is connected to the cathode of the second surge protection diode, the cathode of the first surge protection diode is connected to the third node, and the anode of the second surge protection diode is connected to the fourth node.

5. The totem pole bridgeless circuit as claimed in claim 4, characterized in that: The totem pole bridgeless circuit further includes: a filter unit connected in series between the input AC power supply and the input port of the surge signal detection circuit, wherein the first output end of the filter unit is connected to the first input end of the surge signal detection circuit and the protection input end, and the second output end of the filter unit is connected to the second input end of the surge signal detection circuit and the first bridge arm input end; The surge signal detection circuit comprises: a differential circuit for capturing the surge signal, and a detection voltage divider circuit for providing a reference voltage for the differential circuit. The differential circuit is connected in series between the first output terminal of the filter unit and the detection output terminal of the surge signal detection circuit. One end of the detection voltage divider circuit is connected to a first working voltage end for providing a first working voltage, the other end of the detection voltage divider circuit is connected to a second node, and the voltage divider output end of the detection voltage divider circuit is connected to the detection output end.

6. The totem pole bridgeless circuit as claimed in claim 5, characterized in that: An inductor circuit for filtering is also connected in series between the first node and the fifth node; The surge signal detection circuit further includes: a clamping circuit for performing voltage clamping on the voltage dividing circuit; in, The clamping circuit is connected in parallel with the detection voltage divider circuit. The detection voltage divider circuit comprises: a first resistor and a second resistor connected in series, and a node where the first resistor and the second resistor are connected in series is connected to a detection output terminal; The differential circuit includes a capacitor and a resistor connected in series.

7. The totem pole bridgeless circuit as claimed in claim 6, characterized in that: The clamping circuit comprises: a first clamping diode and a second clamping diode connected in series, the anode of the first clamping diode is connected to the cathode of the second clamping diode, the connection is connected to the detection output terminal, the cathode of the first clamping diode is connected to the first working voltage terminal, and the anode of the first clamping diode is connected to the second node; The surge signal extraction circuit comprises: a first comparison circuit for extracting a positive surge signal, and a second comparison circuit for extracting a negative surge signal. in, The reference voltage input terminal of the comparison circuit is connected to the second node, and the compared voltage input terminal is connected to the detection output terminal.

8. The totem pole bridgeless circuit as claimed in claim 7, characterized in that: The first comparison circuit is a first operational amplifier, and the second comparison circuit is a second operational amplifier. in, The non-inverting input terminal of the first operational amplifier is connected to the detection output terminal, and the inverting input terminal of the first operational amplifier is connected to the voltage-dividing output terminal of the first voltage-dividing circuit. The non-inverting input terminal of the second operational amplifier is connected to the voltage-dividing output terminal of the second voltage-dividing circuit, and the inverting input terminal of the second operational amplifier is connected to the detection output terminal. One end of the working power supply of the first operational amplifier and the second operational amplifier is connected to the first working voltage end, and the other end is connected to the second node. The first voltage dividing circuit and the second voltage dividing circuit are connected between two ends of the working power supply of the operational amplifier.

9. The totem pole bridgeless circuit as claimed in claim 8, characterized in that: The protection control signal includes: a first protection control signal for positive surge protection and a second protection control signal for negative surge protection; The protection control signal circuit includes: a first generation and holding circuit for generating a first protection control signal, and a second generation and holding circuit for generating a second protection control signal. in, The input end of the first generating and holding circuit is connected to the output end of the first operational amplifier, and the output end of the first generating and holding circuit is connected to the control end of the switch tube located between the second node and the third node in the first bridge arm branch and / or the switch tube located between the third node and the fifth node in the second bridge arm branch. The input end of the second generation and holding circuit is connected to the output end of the second operational amplifier, and the output end of the second generation and holding circuit is connected to the control end of the switch tube located between the second node and the fourth node in the first bridge arm branch and / or the switch tube located between the fifth node and the fourth node in the second bridge arm branch.

10. The totem pole bridgeless circuit as claimed in claim 9, characterized in that: The first generation and holding circuit includes a first peak holding circuit and a first duration holding circuit, the second generation and holding circuit includes a second peak holding circuit and a second duration holding circuit, the peak holding circuit is used to hold the peak value of the surge signal output by the surge signal circuit, and the protection duration holding circuit is used to generate a protection control signal and hold the protection duration, in, The first time-holding circuit includes a third operational amplifier, the in-phase input terminal of the third operational amplifier is connected to the output terminal of the first operational amplifier through the first peak holding circuit, and is connected to the voltage-dividing output terminal of the third voltage-dividing circuit, and a first feedback branch for controlling the protection time of the first protection control signal is connected between the in-phase input terminal and the output terminal of the third operational amplifier, the inverting input terminal is connected to the voltage-dividing output terminal of the fourth voltage-dividing circuit, the output terminal of the third operational amplifier is connected to the control terminal of the fifth switch tube for controlling the output of the first protection control signal, one end of the working power supply of the third operational amplifier is connected to the first working voltage terminal, and the other end is connected to the second node, the third voltage-dividing circuit and the fourth voltage-dividing circuit are connected between the working power supplies of the third operational amplifier, and the fifth switch tube is connected in series between the control terminal of the controlled switch tube and the second node, The second time holding circuit includes a fourth operational amplifier, the non-inverting input terminal of the fourth operational amplifier is connected to the output terminal of the second operational amplifier through the second peak holding circuit, and is connected to the voltage divider output terminal of the fifth voltage divider circuit, and a second feedback branch for controlling the protection time of the second protection control signal is connected between the non-inverting input terminal and the output terminal of the fourth operational amplifier, the inverting input terminal is connected to the voltage divider output terminal of the sixth voltage divider circuit, the output terminal of the fourth operational amplifier is connected to the control terminal of the sixth switch tube for controlling the output of the second protection control signal, one end of the working power supply of the fourth operational amplifier is connected to the second working voltage terminal, and the other end is connected to the fourth node, the fifth voltage divider circuit and the sixth voltage divider circuit are connected between the working power supplies of the fourth operational amplifier, and the sixth switch tube is connected in series between the control terminal of the controlled switch tube and the fourth node.

11. The totem pole bridgeless circuit as claimed in claim 9, characterized in that: The first generation and holding circuit includes: a first peak holding circuit and a first time holding circuit, the second generation and holding circuit includes a second peak holding circuit and a second protection time holding circuit, the peak holding circuit is used to hold the surge signal peak value output by the surge signal circuit, and the protection time holding circuit is used to generate a protection control signal and hold the protection time, in, The first time-holding circuit includes a third operational amplifier, the inverting input terminal of the third operational amplifier is connected to the output terminal of the first operational amplifier through the first peak holding circuit, and is connected to the voltage-dividing output terminal of the fourth voltage-dividing circuit, a first feedback branch for controlling the protection time of the first protection control signal is connected between the non-inverting input terminal of the third operational amplifier and the output terminal of the third operational amplifier, and the non-inverting input terminal is connected to the voltage-dividing output terminal of the third voltage-dividing circuit, the output terminal of the third operational amplifier is connected to the control terminal of the controlled switch tube through a first inverting diode for inverting the output signal, the cathode of the first inverting diode is connected to the output terminal, the anode of the first inverting diode is connected to the control terminal of the controlled switch tube, one end of the working power supply of the third operational amplifier is connected to the first working voltage terminal, and the other end is connected to the second node, the third voltage-dividing circuit and the fourth voltage-dividing circuit are connected between the working power supplies of the third operational amplifier, The second protection time holding circuit includes a fourth operational amplifier, the inverting input terminal of the fourth operational amplifier is connected to the output terminal of the second operational amplifier through the second peak holding circuit, and is connected to the voltage divider output terminal of the sixth voltage divider circuit, a second feedback branch for controlling the protection time of the second protection control signal is connected between the non-inverting input terminal of the fourth operational amplifier and the output terminal of the fourth operational amplifier, and the non-inverting input terminal is connected to the voltage divider output terminal of the fifth voltage divider circuit, the output terminal of the fourth operational amplifier is connected to the control terminal of the controlled switch tube through a second inverting diode for inverting the output signal, the cathode of the second inverting diode is connected to the output terminal, the anode of the second inverting diode is connected to the control terminal of the controlled switch tube, one end of the working power supply of the fourth operational amplifier is connected to the second working voltage terminal, and the other end is connected to the fourth node, and the fifth voltage divider circuit and the sixth voltage divider circuit are connected between the working power supplies of the fourth operational amplifier.

12. The totem pole bridgeless circuit according to claim 10 or 11, characterized in that: The peak holding circuit includes a diode, the anode of which is connected to the output end of the surge signal extraction circuit. An isolation circuit for electrical isolation is also included between the output end of the second comparison circuit and the input end of the second peak holding circuit. The feedback branch includes a resistor and a capacitor connected in series. The protection duration depends on the resistance and capacitance of the feedback branch. A resistor feedback branch is also connected between the output terminal and the in-phase input terminal of the operational amplifier in the generate-hold circuit.

13. A power module, characterized in that: The invention comprises a totem pole bridgeless circuit according to any one of claims 1 to 12 and an input AC power supply unit for providing power to the totem pole bridgeless circuit.

14. A surge protection method, characterized in that: The method includes: Detect surge signals in the input AC power supply, When a surge signal is detected, a protection control signal is outputted to control the switch tube to be in a protection off state to protect the surge input totem pole bridgeless circuit, so that: When there is a positive surge in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the negative half cycle to be turned off and put into the protection shutdown state. and / or When there is a negative surge in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube that is turned on in the positive half cycle to be turned off and put into a protection shutdown state.

15. The surge protection method according to claim 14, characterized in that: The protection control signal is a signal for maintaining the protection duration. The method of detecting a surge signal in an input AC power supply comprises: Capture surge signals and their timing; The method of outputting a protection control signal for controlling the switch tube to be in a protection off state to protect the surge input totem pole bridgeless circuit when a surge signal is detected includes: Based on the time at which the detected surge signal occurs, the surge signal at that time is extracted. Based on the extracted surge signal, the generation of the protection control signal is triggered, and the timing of the protection time length of the protection control signal is triggered. in, The protection time is used to control the time the switch tube is in the protection shutdown state; The method further comprises: A protection control signal is provided to a control terminal of at least one switch tube in the totem pole bridgeless circuit.

16. The surge protection method according to claim 15, characterized in that: The step of providing a protection control signal having a protection duration to a control terminal of at least one switch tube in the totem pole bridgeless circuit comprises: When the positive surge signal is located in the negative half cycle of the input AC power supply, the protection control signal controls the switch tube located between the second node and the third node in the first bridge arm branch of the totem pole bridgeless circuit and / or the switch tube located between the third node and the fifth node in the second bridge arm branch. When the negative surge signal is located in the positive half cycle of the input AC power supply, the protection control signal controls the switch tube located between the second node and the fourth node in the first bridge arm branch and / or the switch tube located between the fifth node and the fourth node in the second bridge arm branch. in, The second node is: the serial connection point of the switch tubes in the first bridge arm branch, The third node and the fourth node are two ends of the first bridge arm branch and the second bridge arm branch connected in parallel, wherein the potential of the third node is higher than the potential of the fourth node; The fifth node is: the serial connection point of the switch tubes in the second bridge arm branch.

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