Active clamp converter and DC power supply simulated load

Abstract

An active clamping converter includes: a transformer having a primary winding, a secondary winding and a primary auxiliary winding, wherein the number of turns of the primary auxiliary winding is greater than that of the primary winding; a DC power input circuit; a main switch circuit, which enables the primary winding to generate a first alternating magnetic field based on the DC power; an auxiliary switch circuit, which converts the induced AC power of the primary auxiliary winding into induced DC power; a clamping energy storage circuit, whose clamping end receives the induced DC power to reach a first voltage, and whose peak absorption end is connected to the primary winding; when the peak voltage of the primary winding is greater than the first voltage, the peak power exceeding the first voltage is absorbed, and a second alternating magnetic field synchronized with the first alternating magnetic field is generated; and the secondary winding generates output power. Since the number of turns of the primary auxiliary winding is greater than that of the primary winding, the portion of the peak voltage greater than the platform voltage is effectively absorbed, and the absorption degree is too heavy to be burned out. The present application also provides a DC power supply simulation load.

Description

Technical Field

[0001] The present application relates to the technical field of power supply, and in particular to an active clamping converter and a DC power supply simulation load. Background Art

[0002] A power converter is an electronic device that converts electrical energy from one form to another, such as boosting DC power for output to meet different power needs. Since the power converter usually performs power conversion based on a transformer by shutting down a field effect tube during the conversion of DC power, there will be a spike voltage at the moment the field effect tube is disconnected. The spike voltage is mainly generated by the leakage inductance of the primary side of the transformer, which is the part of the magnetic flux that is lost during the coupling process between the primary and secondary sides of the transformer. The voltage value of the spike voltage is usually relatively high, so it is easy to damage the field effect tube.

[0003] To solve this problem, we can choose a field effect tube with a higher withstand voltage, but this will increase the cost of the field effect tube. Therefore, we usually add an active clamping circuit to absorb the peak voltage to avoid the field effect tube from being damaged by excessive peak voltage.

[0004] However, in the current technical solution, the active clamping circuit usually clamps the DS platform voltage of the field effect tube based on a clamping voltage of a fixed voltage value. However, the DS platform voltage of the field effect tube (i.e., the voltage difference between the D pole and the S pole of the field effect tube) fluctuates, which causes the active clamping circuit to be unable to effectively absorb the spike voltage, and there is also a risk of being burned out due to excessive absorption. For example, when the platform voltage fluctuates upward, the active clamping circuit may also absorb the DS platform voltage (for example, when the DS platform voltage is greater than the clamping voltage), which easily causes the active clamping circuit to be burned out due to excessive absorption. For example, when the DS platform voltage fluctuates downward, when there is a small spike voltage, the spike voltage active clamping circuit will be unable to absorb the spike voltage (for example, when the spike voltage is less than the clamping voltage), so it can only absorb a larger spike voltage, but not a smaller spike voltage.

[0005] In general, the active clamping circuit in the current technical solution cannot ensure effective absorption of the peak voltage when absorbing the peak voltage, and there is a risk of burning out due to excessive absorption. Therefore, a new technical solution is needed. Summary of the invention

[0006] The main technical problem solved by the present application is that the active clamping circuit cannot effectively absorb the peak voltage and there is a risk of burning out.

[0007] According to a first aspect, an active clamping converter is provided in an embodiment, comprising:

[0008] A transformer having a primary winding, a secondary winding and a primary auxiliary winding;

[0009] a DC power input circuit, whose input end is used to input DC power and whose output end is used to output the DC power to the primary winding;

[0010] a main switch circuit connected to the primary winding to control the DC power to flow through the primary winding so that the primary winding generates a first alternating magnetic field based on the DC power;

[0011] an auxiliary switch circuit connected to the primary auxiliary winding, and configured to convert the induced AC power into induced DC power when the primary auxiliary winding generates induced AC power based on the first alternating magnetic field;

[0012] A clamping tank circuit, wherein the clamping end is used to receive the induced DC power, and the peak absorption end is used to connect the primary winding; the clamping end of the clamping tank circuit reaches a first voltage based on the induced DC power, wherein the number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, so that the first voltage is greater than a second voltage generated by the primary winding based on the DC power;

[0013] When the peak voltage generated by the primary winding based on the leakage inductance is greater than the first voltage, the clamping tank circuit absorbs the peak electric energy of the peak voltage exceeding the first voltage to the clamping end, and the auxiliary switch circuit is further used to control the peak electric energy to flow through the primary auxiliary winding, so that the primary auxiliary winding generates a second alternating magnetic field synchronized with the first alternating magnetic field based on the peak electric energy;

[0014] The secondary winding generates output electrical energy based on the first alternating magnetic field and the second alternating magnetic field.

[0015] In some embodiments, the auxiliary switch circuit includes a first auxiliary switch tube, a second auxiliary switch tube, a first capacitor and a second capacitor;

[0016] The first end of the first auxiliary switch tube is connected to the first end of the primary auxiliary winding through the first capacitor, and the second end is respectively connected to the first end of the second auxiliary switch tube and the second end of the primary auxiliary winding, and the second end of the second auxiliary switch tube is connected to the first end of the primary auxiliary winding through the second capacitor; the node between the first auxiliary switch tube and the first capacitor is connected to the clamping end of the clamping tank circuit, and the node between the second auxiliary switch tube and the second capacitor is grounded;

[0017] The control end of the first auxiliary switch tube is used to input a first control signal, and the control end of the second auxiliary switch tube is used to input a second control signal. The first auxiliary switch tube and the second auxiliary switch tube are alternately turned on under the control of the first control signal and the second control signal, respectively, to convert the induced AC power into induced DC power, and control the peak power to flow through the primary auxiliary winding alternately in different directions.

[0018] In some embodiments, the primary auxiliary winding has a first end, a second end, and a tap end arranged between the first end and the second end, and the tap end is connected to the clamp end of the clamp tank circuit; the auxiliary switch circuit includes a third auxiliary switch tube and a fourth auxiliary switch tube;

[0019] The first end of the third auxiliary switch tube is connected to the first end of the primary auxiliary winding, the first end of the fourth auxiliary switch tube is connected to the second end of the primary auxiliary winding, and the second end of the third auxiliary switch tube and the second end of the fourth auxiliary switch tube are grounded respectively;

[0020] The control end of the third auxiliary switch tube is used to input a third control signal, and the control end of the fourth auxiliary switch tube is used to input a fourth control signal. The third auxiliary switch tube and the fourth auxiliary switch tube are alternately turned on under the control of the third control signal and the fourth control signal, respectively, to convert the induced AC power energy into induced DC power energy, and control the peak power energy to flow through the primary auxiliary winding alternately in different directions.

[0021] In some embodiments, the clamp tank circuit comprises:

[0022] An energy storage circuit, wherein a first end of the energy storage circuit is used to receive the induced DC power and a second end of the energy storage circuit is grounded; the energy storage circuit stores energy based on the DC power and makes the first end of the energy storage circuit reach the first voltage;

[0023] A clamping circuit, wherein the first end and the second end are respectively used to connect the two ends of the primary winding, and the third end is connected to the first end of the energy storage circuit; the clamping circuit is used to be turned on when the peak voltage at the two ends of the primary winding is greater than the first voltage, so that the energy storage circuit absorbs the peak electrical energy of the peak voltage that exceeds the first voltage.

[0024] In some embodiments, the clamping circuit includes a first diode and a second diode, and the energy storage circuit includes an energy storage capacitor;

[0025] The positive electrode of the first diode and the positive electrode of the second diode are respectively connected to the two ends of the primary winding, the negative electrode of the first diode and the negative electrode of the second diode are both connected to the first end of the energy storage capacitor, and the second end of the energy storage capacitor is grounded;

[0026] The first diode and the second diode are both used for conducting when the peak voltage at the anode thereof is greater than the first voltage, so that the energy storage capacitor absorbs the peak electrical energy of the peak voltage exceeding the first voltage.

[0027] In some embodiments, the main switch circuit includes a first main switch tube and a second main switch tube;

[0028] The first end of the first main switch is connected to the first end of the primary winding, the first end of the second main switch is connected to the second end of the primary winding, and the second end of the first main switch and the second end of the second main switch are grounded respectively;

[0029] The control end of the first main switch tube is used to input a fifth control signal, and the control end of the second main switch tube is used to input a sixth control signal. The first main switch tube and the second main switch tube are at least alternately turned on under the control of the fifth control signal and the sixth control signal, respectively, to control the DC power to flow through the primary winding alternately in different directions.

[0030] In some embodiments, the DC power input circuit is further used to at least boost the DC power and then output it to the primary winding.

[0031] In some embodiments, the DC power input circuit includes a third capacitor, a first inductor, and a second inductor;

[0032] The first ends of the first inductor and the second inductor are respectively used to input the DC power, the second end of the first inductor is connected to the first end of the primary winding, and the second end of the second inductor is connected to the second end of the primary winding;

[0033] The first end of the third capacitor is used to input the DC power, and the second end is grounded;

[0034] The first inductor and the second inductor are used to alternately store energy when the main switch circuit controls the DC power to flow through the primary winding, and based on the stored energy, the DC power is alternately boosted and output to the primary winding; the third capacitor is used to filter the DC power.

[0035] In some embodiments, the primary winding has a first end, a second end, and a tap end disposed between the first end and the second end; the DC power input circuit includes a fourth capacitor and a third inductor;

[0036] The first end of the third inductor is used to input the DC power, and the second end is connected to the tap end of the primary winding; the first end of the third capacitor is used to input the DC power, and the second end is grounded;

[0037] The third inductor is used to store energy when the first end and the second end of the primary winding are both grounded, and based on the stored energy, when the main switch circuit controls the DC power to flow through the primary winding, the DC power is boosted and output to the primary winding; the third capacitor is used to filter the DC power.

[0038] According to a second aspect, an embodiment provides a DC power supply simulated load, comprising the active clamp converter as described in the first aspect.

[0039] According to the active clamp converter of the above embodiment, when the primary winding generates the first alternating magnetic field, the primary auxiliary winding generates induced AC power based on the first alternating magnetic field, and the auxiliary switch circuit converts the induced AC power into induced DC power, and makes the clamping end of the clamping energy storage circuit reach the first voltage. Since the number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, the induced electromotive force generated by the primary auxiliary winding is greater than the electromotive force of the primary winding, so that the first voltage is greater than the second voltage generated by the primary winding based on DC power, and the first voltage and the second voltage always maintain a certain proportional relationship, so that no matter how the second voltage at both ends of the primary winding fluctuates, it is always ensured that the first voltage used for clamping is always greater than the second voltage at both ends of the primary winding. When the primary winding generates a spike voltage based on leakage inductance, the clamping energy storage circuit can absorb the spike power exceeding the first voltage in the spike voltage, and the first voltage is always greater than the second voltage, so as to ensure that the portion of the spike voltage greater than the second voltage is effectively absorbed, so as to avoid the clamping energy storage circuit from absorbing the second voltage too much and being burned. The auxiliary switching circuit is also used to control the absorbed peak electrical energy to flow through the primary auxiliary winding, so that the primary auxiliary winding generates a second alternating magnetic field synchronized with the first alternating magnetic field based on the peak electrical energy, and the secondary winding generates output electrical energy based on the first alternating magnetic field and the second alternating magnetic field, thereby realizing the recycling of the peak electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic diagram of the structure of an active clamp converter according to an embodiment;

[0041] Figure 2 It is a structural schematic diagram of the first embodiment of the active clamping converter;

[0042] Figure 3 It is a structural schematic diagram of a second embodiment of an active clamping converter;

[0043] Figure 4 It is a structural schematic diagram of a third embodiment of an active clamping converter;

[0044] Figure 5It is a structural schematic diagram of a fourth embodiment of an active clamping converter;

[0045] Figure 6 The figure is a schematic diagram of the structure of a DC power supply simulating a load according to an embodiment. DETAILED DESCRIPTION

[0046] The present application is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments use associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and the related operations can be fully understood according to the description in the specification and the general technical knowledge in the art.

[0047] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0048] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0049] In the current technical solution, when the DS platform voltage of the field effect tube is clamped based on a clamping voltage with a fixed voltage value, since the DS platform voltage fluctuates, the active clamping circuit cannot effectively absorb the peak voltage when the DS platform voltage fluctuates, and there is a risk of burning out.

[0050] In some embodiments of the present application, since the voltage used for clamping is obtained based on the induced electromotive force of the primary auxiliary winding, and the number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, when the voltage generated at both ends of the primary winding based on DC power fluctuates, the voltage used for clamping will also fluctuate accordingly, so that the voltage used for clamping is always greater than the voltage generated at both ends of the primary winding based on DC power. Therefore, when the primary winding generates a spike voltage based on leakage inductance, the spike power that exceeds the voltage used for clamping can be absorbed, and the voltage used for clamping always maintains a certain proportional relationship with the voltage generated at both ends of the primary winding based on DC power, thereby ensuring effective absorption of the spike voltage and avoiding the clamping energy storage circuit from absorbing the voltage generated at both ends of the primary winding based on DC power, which results in excessive absorption and burning.

[0051] Some embodiments provide an active clamping converter, which is used to absorb and recycle the peak voltage generated by the primary winding, and can effectively absorb the peak voltage and avoid burning due to excessive absorption. Figure 1 The active clamp converter includes a transformer 10, a DC power input circuit 20, a main switch circuit 30, an auxiliary switch circuit 40 and a clamp energy storage circuit 50, which are described in detail below.

[0052] The transformer 10 is used to generate an alternating magnetic field or alternating electric energy based on electromagnetic induction. In some embodiments, the transformer has a primary winding, a secondary winding, and a primary auxiliary winding. The primary winding is coupled to the secondary winding and the primary auxiliary winding, respectively, and the primary auxiliary winding is also coupled to the secondary winding, so that the energy on the primary winding can be transferred to the secondary winding and the primary auxiliary winding, respectively, and the energy on the primary auxiliary winding can also be transferred to the secondary winding.

[0053] The input end of the DC power input circuit 20 is used to input DC power, and outputs the DC power to the primary winding through its output end. In some embodiments, the DC power input circuit 20 can also boost and filter the DC power before outputting it to the primary winding, so that the input voltage of the DC power can have a wider voltage range, and within the wider voltage range, the DC power input circuit 20 can boost the DC power to a voltage that meets the requirements.

[0054] The main switch circuit 30 is connected to the primary winding so that the DC power flows through the primary winding, so that the primary winding generates a first alternating magnetic field based on the DC power. In some embodiments, the main switch circuit 30 is used to control the DC power to flow through the primary winding alternately in different directions, so that the primary winding generates a first alternating magnetic field. The first alternating magnetic field can respectively cause the secondary winding and the primary auxiliary winding to generate corresponding induced AC power.

[0055] The auxiliary switch circuit 40 is connected to the primary auxiliary winding, and is used to convert the induced AC power into induced DC power when the primary auxiliary winding generates induced AC power based on the first alternating magnetic field. In some embodiments, when the primary auxiliary winding generates induced AC power based on the first alternating magnetic field, the auxiliary switch circuit 40 is used to control the induced AC power to be output in the same direction, thereby obtaining induced DC power.

[0056] The clamping tank circuit 50 is used to clamp the voltage across the primary winding, and absorb the peak voltage when the peak voltage generated by the primary winding based on the leakage inductance is greater than the clamping voltage. In some embodiments, the clamping tank circuit 50 has a clamping end and a peak absorption end, and the clamping end is used to receive the induced DC power converted by the auxiliary switch circuit, so that the clamping end of the clamping tank circuit 50 reaches a first voltage based on the induced DC power, and the first voltage is used as the clamping voltage. The peak absorption end of the clamping tank circuit 50 is used to connect the primary winding, and when the peak voltage generated by the primary winding based on the leakage inductance is greater than the first voltage, the clamping tank circuit 50 absorbs the peak power exceeding the first voltage in the peak voltage to its clamping end. The number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, so that the first voltage is greater than the second voltage generated by the primary winding based on the input DC power.

[0057] After the clamping energy storage circuit 50 absorbs the peak electric energy, the auxiliary switch circuit 40 is also used to control the peak electric energy to flow through the primary auxiliary winding, so that the primary auxiliary winding generates a second alternating magnetic field synchronized with the first alternating magnetic field based on the peak electric energy, and the secondary winding generates output electric energy based on the synchronized first alternating magnetic field and the second alternating magnetic field. In some embodiments, the auxiliary switch circuit 40 is used to control the peak electric energy to flow through the primary auxiliary winding alternately in different directions, and the alternating control is synchronized with the main switch circuit 30 controlling the DC electric energy to flow through the primary winding alternately in different directions, for example, the frequency and direction of the control are consistent.

[0058] In the above embodiment, the primary auxiliary winding is coupled to the primary winding, and the primary auxiliary winding and the auxiliary switch circuit 40 are equivalent to forming a DC power supply, which can convert the induced alternating electric energy generated by the primary auxiliary winding into induced DC electric energy, and output it to the clamping energy storage circuit 50, so that the clamping end of the clamping energy storage circuit 50 reaches a first voltage based on the induced DC electric energy, and the first voltage is used for the clamping energy storage circuit 50 to clamp the two ends of the primary winding. Since the number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, the induced electromotive force generated by the primary auxiliary winding is greater than the electromotive force of the primary winding, so that the first voltage is greater than the second voltage generated by the primary winding based on the DC electric energy, and the first voltage and the second voltage always maintain a certain proportional relationship based on the ratio of the number of turns of the primary auxiliary winding and the primary winding, so that no matter how the second voltage at the two ends of the primary winding fluctuates, it can always be ensured that the first voltage used for clamping is always greater than the second voltage at the two ends of the primary winding.

[0059] When the peak voltage generated by the primary winding based on the leakage inductance is greater than the first voltage, the clamping tank circuit 50 absorbs the peak electric energy in the peak voltage that exceeds the first voltage. At this time, the clamping tank circuit 50 and the auxiliary switch circuit 40 are equivalent to forming an AC power supply, which can convert the peak electric energy absorbed by the clamping tank circuit 50 into alternating peak electric energy and output it to the primary auxiliary winding, so that the primary auxiliary winding generates a second alternating magnetic field synchronized with the first alternating magnetic field based on the alternating peak electric energy. The secondary winding then generates output electric energy based on the synchronized first alternating magnetic field and second alternating magnetic field, thereby recovering the excess energy in the peak voltage based on the primary auxiliary winding and coupling it to the secondary winding synchronously with the primary winding.

[0060] In the above embodiment, since the number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, the first voltage is always greater than the second voltage generated by the primary winding based on the DC power. This ensures that only the portion of the peak voltage that is greater than the second voltage is effectively absorbed, so as to avoid the clamping energy storage circuit from absorbing the second voltage too much and being burned out. The auxiliary switch circuit is also used to control the absorbed peak power to flow through the primary auxiliary winding, so that the primary auxiliary winding generates a second alternating magnetic field synchronized with the first alternating magnetic field based on the peak power, and the secondary winding generates output power based on the first alternating magnetic field and the second alternating magnetic field, thereby realizing the recycling of the peak power and improving the energy recovery efficiency.

[0061] The above is some description of various circuits in the active clamp converter. The following is a specific description of a specific embodiment of the active clamp converter.

[0062] Embodiment 1:

[0063] Please refer to Figure 2The primary winding (N1, N2) of the transformer T1 has a first end, a second end, and a tap end arranged between the first end and the second end. The primary auxiliary winding (N4) of the transformer T1 has a first end and a second end.

[0064] The input end of the DC power input circuit 20 is used to receive DC power (INPUT), and the output end of the DC power input circuit 20 is connected to the tap end of the primary winding to output the DC power to the primary winding. In some embodiments, the DC power input circuit 20 includes a fourth capacitor E1 and a third inductor L1, a first end of the third inductor L1 is used to input DC power, a second end of the third inductor L1 is connected to the tap end of the primary winding, a first end of the third capacitor is used to input DC power, and a second end of the third capacitor is grounded.

[0065] The main switch circuit 30 includes a first main switch tube Q1 and a second main switch tube Q2. The first end of the first main switch tube Q1 is connected to the first end of the primary winding, the first end of the second main switch tube Q2 is connected to the second end of the primary winding, the second end of the first main switch tube Q1 and the second end of the second main switch tube Q2 are grounded respectively, the control end of the first main switch tube Q1 is used to input the fifth control signal, and the control end of the second main switch tube Q2 is used to input the sixth control signal. In this embodiment, the first main switch tube Q1 is used to be turned on when the fifth control signal is at an effective level, and the second main switch tube Q2 is used to be turned on when the sixth control signal is at an effective level, for example, the effective levels of the fifth control signal and the sixth control signal are both high levels.

[0066] The auxiliary switch circuit 40 includes a first auxiliary switch tube Q3, a second auxiliary switch tube Q4, a first capacitor C3, and a second capacitor C4. Among them, the first end of the first auxiliary switch tube Q3 is connected to the first end of the primary auxiliary winding through the first capacitor C3, the second end of the first auxiliary switch tube Q3 is connected to the second end of the primary auxiliary winding and the first end of the second auxiliary switch tube Q4 respectively, the second end of the second auxiliary switch tube Q4 is connected to the first end of the primary auxiliary winding through the second capacitor C4, the control end of the first auxiliary switch tube Q3 is used to input the first control signal, and the control end of the second auxiliary switch tube Q4 is used to input the second control signal. The node between the first auxiliary switch tube Q3 and the first capacitor C3 is connected to the clamping end of the clamping tank circuit 50, and the node between the second auxiliary switch tube Q4 and the second capacitor C4 is grounded. In this embodiment, the first auxiliary switch tube Q3 is used to turn on when the first control signal is at an effective level, and the second auxiliary switch tube Q4 is used to turn on when the second control signal is at an effective level, for example, the effective levels of the first control signal and the second control signal are both high levels.

[0067] The clamping energy storage circuit 50 includes an energy storage circuit and a clamping circuit. The first end of the energy storage circuit is connected to the node between the first auxiliary switch tube Q3 and the first capacitor C3, and the second end of the energy storage circuit is grounded. The first end of the clamping circuit is connected to the first end of the primary winding, the second end of the clamping circuit is connected to the second end of the primary winding, and the third end of the clamping circuit is connected to the clamping end of the energy storage circuit. In this embodiment, the clamping end of the energy storage circuit is used to receive the induced DC power converted by the auxiliary switch circuit 40, so that the energy storage circuit stores energy based on the induced DC power and makes its clamping end reach a first voltage, that is, the clamping voltage.

[0068] The first end and the second end of the clamping circuit are respectively used to input the voltage across the primary winding. The clamping circuit is used to turn on when the peak voltage generated across the primary winding based on the leakage inductance is greater than the first voltage, and enable the energy storage circuit to absorb the peak electrical energy in the peak voltage that exceeds the first voltage.

[0069] In some embodiments, the clamping circuit includes a first diode D1 and a second diode D2, and the energy storage circuit includes an energy storage capacitor C2. The anode of the first diode D1 is connected to the first end of the primary winding, the anode of the second diode D2 is connected to the second end of the primary winding, the first end of the energy storage capacitor C2 is connected to the cathode of the first diode D1 and the cathode of the second diode D2, respectively, and the second end of the energy storage capacitor C2 is grounded. In this embodiment, the first diode D1 and the second diode D2 are unidirectionally conductive, so they are only conductive when the peak voltage of the primary winding is greater than the first voltage of the first end of the energy storage capacitor C2, and only absorb the peak electrical energy of the peak voltage that exceeds the first voltage.

[0070] In the above embodiments, the first auxiliary switch tube Q3, the second auxiliary switch tube Q4, the first main switch tube Q1 and the second main switch tube Q2 can all be N-channel field effect tubes or NPN transistors. In some embodiments, they can also be PNP transistors or P-channel field effect tubes, and the connection relationship between them can be adaptively changed.

[0071] The above is some description of the first embodiment of the active clamping converter. The working principle thereof will be described in detail below.

[0072] The DC power is a DC input. When its voltage meets the preset input voltage, it is filtered by the fourth capacitor E1 and then input to the tap end of the primary winding through the third inductor L1. At this time, the first main switch tube Q1 is controlled by the fifth control signal, and the second main switch tube Q2 is controlled by the sixth control signal, so that the first main switch tube Q1 and the second main switch tube Q2 are alternately turned on at a first frequency. When the first main switch tube Q1 is turned on, the DC power flows from the tap end of the primary winding to the first end of the primary winding, and when the second main switch tube Q2 is turned on, the DC power flows from the tap end of the primary winding to the second end of the primary winding, so that the primary winding generates a first alternating magnetic field of the first frequency.

[0073] In some embodiments, when the voltage of the DC power is lower than the preset input voltage, the first main switch tube Q1 and the second main switch tube Q2 can be turned on at the same time by adjusting the fifth control signal and the sixth control signal, for example, the duty cycle of the fifth control signal and the sixth control signal is adjusted to be greater than 50%. When the first main switch tube Q1 and the second main switch tube Q2 are turned on at the same time, the primary winding is equivalent to being short-circuited, so that no alternating magnetic field is generated, and the third inductor L1 can store energy when current flows through, and when the first main switch tube Q1 and the second main switch tube Q2 are alternately turned on at the first frequency again, the third inductor L1 releases the stored energy, thereby raising the voltage of the DC power to meet the preset input voltage. Since the voltage of the DC power can be raised, the voltage of the DC power can have a larger range and meet the preset input voltage requirements.

[0074] When the primary winding generates a first alternating magnetic field of a first frequency, the primary auxiliary winding generates corresponding induced AC power based on the first alternating magnetic field. At this time, the first auxiliary switch tube Q3 is controlled by the first control signal, and the second auxiliary switch tube Q4 is controlled by the second control signal, so that the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 are also alternately turned on at the first frequency, and the alternating turn-on of the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 is synchronized with the alternating turn-on of the first main switch tube Q1 and the second main switch tube Q2, that is, when the first main switch tube Q1 is turned on, the first auxiliary switch tube Q3 is also turned on, and when the second main switch tube Q2 is turned on, the second auxiliary switch tube Q4 is also turned on. Since the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 form a half-bridge circuit, the induced AC power generated by the primary auxiliary winding based on the first alternating magnetic field can be converted into induced DC power, and output to the first end of the energy storage capacitor C2, so that the first end of the energy storage capacitor C2 reaches a first voltage, that is, a clamping voltage. For example, when the first end of the primary auxiliary winding is the inductive positive terminal, the second auxiliary switch tube Q4 is turned on, and when the second end of the primary auxiliary winding is the inductive positive terminal, the first auxiliary switch tube Q3 is turned on, and the first capacitor C3 and the second capacitor C4 are used to block direct current to prevent the primary auxiliary winding from short-circuiting, and at the same time, the induced direct current power can be filtered. Based on the alternating conduction of the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4, the first voltage at the first end of the energy storage capacitor C2 is a multiple of the induced voltage of the primary auxiliary winding. Based on the alternating conduction of the first main switch tube Q1 and the second main switch tube Q2, the potential of the first end of the first main switch tube Q1 and the first end of the second main switch tube Q2 is a multiple of the direct current power, or a multiple of the direct current power after boosting.

[0075] The positive electrode of the first diode D1 and the positive electrode of the second diode D2 are respectively input with the voltage at both ends of the primary winding, and the negative electrode of the first diode D1 and the negative electrode of the second diode D2 are respectively the first voltage. In this embodiment, the number of turns from the first end of the primary winding to the tap end is equal to the number of turns from the tap end to the second end of the primary winding, and the number of turns of the primary auxiliary winding is greater than the number of turns. Therefore, when there is no peak voltage generated based on leakage inductance at both ends of the primary winding, its electromotive force is always lower than the induced electromotive force of the primary auxiliary winding, that is, the second voltage generated based on DC power at both ends of the primary winding is always lower than the clamping voltage at the first end of the energy storage capacitor C2, wherein the second voltage is also the DS platform voltage of the first main switch tube Q1 and the first main switch tube Q2. In some embodiments, the number of turns of the primary auxiliary winding can be one more turn, so that the clamping voltage is always slightly greater than the DS platform voltage of the main switch tube, so no matter how the DS platform voltage fluctuates, the clamping energy storage circuit 50 will not absorb the DS platform voltage, thereby avoiding burning. When the primary winding generates a spike voltage based on leakage inductance, the spike voltage can be understood as the DS platform voltage superimposed on the self-inductance voltage of the primary auxiliary winding based on leakage inductance. Therefore, even a smaller leakage inductance will make the spike voltage greater than the clamping voltage, so that the clamping energy storage circuit 50 absorbs the spike voltage to ensure effective absorption of the spike voltage and avoid burning out due to absorbing the DS platform voltage.

[0076] When the primary winding generates a spike voltage based on leakage inductance, the clamping energy storage circuit can absorb the spike electrical energy in the spike voltage that exceeds the clamping voltage, and the clamping voltage is always greater than the DS platform voltage, thereby ensuring that the portion of the spike voltage that is greater than the DS platform voltage is effectively absorbed. At this time, since the spike voltage is greater than the first voltage reached based on the induced DC power, the original induced DC power flows from the primary auxiliary winding to the first end of the energy storage capacitor C2, and is changed to the spike electrical energy from the first end of the energy storage capacitor C2 flowing to the primary auxiliary winding, and when the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 are alternately turned on, the peak electrical energy flowing from the first end of the energy storage capacitor C2 to the primary auxiliary winding alternately flows through the primary auxiliary winding from different directions. For example, when the first auxiliary switch tube Q3 is turned on, the spike electrical energy The peak electric energy flows from the second end of the primary auxiliary winding to the first end. When the second auxiliary switch tube Q4 is turned on, the peak electric energy flows from the first end of the primary auxiliary winding to the second end, so that the primary auxiliary winding generates a second alternating magnetic field. Since the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 are turned on alternately and synchronously with the first main switch tube Q1 and the second main switch tube Q2, the second alternating magnetic field is also synchronized with the first alternating magnetic field. The secondary winding (N3) obtains output electric energy (OUT) based on the synchronized second alternating magnetic field and the first alternating magnetic field.

[0077] In the current technical solution, since the active clamping circuit is usually based on the energy storage capacitor to absorb the peak voltage, for example, based on the shutdown control of the switch device, so that the energy storage capacitor absorbs the peak voltage when the switch device is turned on, since the shutdown of the switch device is not absolutely stable, the switch device may be turned off at the same time as the field effect transistor in the power converter, resulting in a short circuit, or through the bridging effect of the switch device, causing resonance between the energy storage capacitor and the energy storage inductor, thereby affecting the normal operation of the power converter, and there is also a risk of burning. In the above embodiment, since the primary winding and the primary auxiliary winding are electrically isolated, and the first diode D1 and the second diode D2 both have the characteristic of forward conduction, the current between the energy storage capacitor C2 and the third inductor L1 is unidirectional, thereby effectively blocking the resonance between the energy storage capacitor C2 and the third inductor L1, and improving the safety and stability of the circuit.

[0078] Embodiment 2:

[0079] Please refer to Figure 3 The difference between this embodiment and the first embodiment is that the primary winding (N1) of the transformer T1 has a first end and a second end, and the first output end of the DC power input circuit 20 is connected to the first end of the primary winding, and the second output end of the DC power input circuit 20 is connected to the second end of the primary winding, which is described in detail below.

[0080] The DC power input circuit 20 includes a third capacitor E1 and a first inductor L1 and a second inductor L2. The first ends of the first inductor L1 and the second inductor L2 are respectively used to receive input DC power, the second end of the first inductor L1 is connected to the first end of the primary winding, the second end of the second inductor L2 is connected to the second end of the primary winding, the first end of the third capacitor E1 is used to receive DC power, and the second end of the third capacitor E1 is grounded.

[0081] When the voltage of the DC power is lower than the preset input voltage, the first main switch tube Q1 and the second main switch tube Q2 can be turned on alternately or simultaneously by adjusting the fifth control signal and the sixth control signal, for example, adjusting the duty ratio of the fifth control signal and the sixth control signal. When the first main switch tube Q1 and the second main switch tube Q2 are turned on simultaneously, the primary winding is equivalent to being short-circuited, so that no alternating magnetic field is generated, and the first inductor L1 and the second inductor L2 can store energy when current flows through them, and when the first main switch tube Q1 and the sixth transistor are turned on alternately at the first frequency, the first inductor L1 and the second inductor L2 release the stored energy respectively, thereby raising the voltage of the DC power to meet the preset input voltage. The first main switch tube Q1 and the second main switch tube Q2 are alternately turned on for explanation. When the first main switch tube Q1 is turned on and the second main switch tube Q2 is turned off, the second inductor L2 stores energy when current flows through, and the first inductor L1 releases the stored energy. When the second main switch tube Q2 is turned on and the first main switch tube Q1 is turned off, the first inductor L1 stores energy when current flows through, and the second inductor L2 releases the stored energy, thereby raising the voltage of the DC power to meet the preset input voltage.

[0082] Since the voltage of the DC power can be raised, the voltage of the DC power can have a larger range and meet the preset input voltage requirement.

[0083] Embodiment three:

[0084] Please refer to Figure 4 The difference between this embodiment and the first embodiment lies in that the primary auxiliary winding (N4, N5) has a first end, a second end, and a tap end arranged between the first end and the second end, and the auxiliary switch circuit 40 is different. The auxiliary switch circuit 40 of this embodiment is specifically described below.

[0085] The auxiliary switch circuit 40 includes a third auxiliary switch tube Q4 and a fourth auxiliary switch tube Q3. The first end of the third auxiliary switch tube Q4 is connected to the first end of the primary auxiliary winding, the first end of the fourth auxiliary switch tube Q3 is connected to the second end of the primary auxiliary winding, and the second end of the third auxiliary switch tube Q4 and the second end of the fourth auxiliary switch tube Q3 are grounded respectively. The control end of the third auxiliary switch tube Q4 is used to input a third control signal, and the control end of the fourth auxiliary switch tube Q3 is used to input a fourth control signal.

[0086] When the primary winding (N1, N2) generates a first alternating magnetic field of a first frequency, the primary auxiliary winding generates corresponding induced AC power based on the first alternating magnetic field. At this time, the third auxiliary switch tube Q4 is controlled by the third control signal, and the fourth auxiliary switch tube Q3 is controlled by the fourth control signal, so that the third auxiliary switch tube Q4 and the fourth auxiliary switch tube Q3 are also alternately turned on at the first frequency, and the alternating turn-on of the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 is synchronized with the alternating turn-on of the first main switch tube Q1 and the second main switch tube Q2, that is, when the first main switch tube Q1 is turned on, the first auxiliary switch tube Q3 is also turned on, and when the second main switch tube Q2 is turned on, the second auxiliary switch tube Q4 is also turned on. Since the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 constitute a push-pull circuit, the induced AC power generated by the primary auxiliary winding based on the first alternating magnetic field can be converted into induced DC power, and output to the first end of the energy storage capacitor C2, so that the first end of the energy storage capacitor C2 reaches a first voltage, that is, a clamping voltage. For example, when the first end of the primary auxiliary winding is the inductive positive terminal, the fourth auxiliary switch tube Q3 is turned on, so that the tap end of the primary auxiliary winding is the positive electrode, and when the second end of the primary auxiliary winding is the inductive positive terminal, the third auxiliary switch tube Q4 is turned on, so that the tap end of the primary auxiliary winding is still the positive electrode. Thus, the tap end of the primary auxiliary winding outputs the inductive DC energy to the first end of the energy storage capacitor C2.

[0087] On the contrary, when the first end of the energy storage capacitor C2 outputs peak electrical energy to the tap end of the primary auxiliary winding, the third auxiliary switch tube Q4 and the fourth auxiliary switch tube Q3 are alternately turned on under the control of the third control signal and the fourth control signal, respectively, so that the peak electrical energy alternately flows through the primary auxiliary winding and generates a second alternating magnetic field synchronized with the first alternating magnetic field.

[0088] In this embodiment, the number of turns from the first end to the tap end of the primary winding (i.e., the number of turns of N1) is equal to the number of turns from the tap end to the second end of the primary winding (i.e., the number of turns of N2), the number of turns from the first end to the tap end of the primary auxiliary winding (i.e., the number of turns of N4) is equal to the number of turns from the tap end to the second end of the primary winding (i.e., the number of turns of N5), and the number of turns of N1 is greater than the number of turns of N4, so when no peak voltage is generated at both ends of the primary winding due to leakage inductance, its electromotive force is always lower than the induced electromotive force of the primary auxiliary winding.

[0089] Embodiment 4:

[0090] Please refer to Figure 5 The difference between this embodiment and the second embodiment lies in that the primary auxiliary winding (N4, N5) has a first end, a second end, and a tap end arranged between the first end and the second end, and the auxiliary switch circuit 40 is different. The auxiliary switch circuit 40 of this embodiment is specifically described below.

[0091] The auxiliary switch circuit 40 includes a third auxiliary switch tube Q4 and a fourth auxiliary switch tube Q3. The first end of the third auxiliary switch tube Q4 is connected to the first end of the primary auxiliary winding, the first end of the fourth auxiliary switch tube Q3 is connected to the second end of the primary auxiliary winding, and the second end of the third auxiliary switch tube Q4 and the second end of the fourth auxiliary switch tube Q3 are grounded respectively. The control end of the third auxiliary switch tube Q4 is used to input a third control signal, and the control end of the fourth auxiliary switch tube Q3 is used to input a fourth control signal.

[0092] When the primary winding (N1) generates a first alternating magnetic field of a first frequency, the primary auxiliary winding generates corresponding induced AC power based on the first alternating magnetic field. At this time, the third auxiliary switch tube Q4 is controlled by the third control signal, and the fourth auxiliary switch tube Q3 is controlled by the fourth control signal, so that the third auxiliary switch tube Q4 and the fourth auxiliary switch tube Q3 are also alternately turned on at the first frequency, and the alternating turn-on of the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 is synchronized with the alternating turn-on of the first main switch tube Q1 and the second main switch tube Q2, that is, when the first main switch tube Q1 is turned on, the first auxiliary switch tube Q3 is also turned on, and when the second main switch tube Q2 is turned on, the second auxiliary switch tube Q4 is also turned on. Since the first auxiliary switch tube Q3 and the second auxiliary switch tube Q4 constitute a push-pull circuit, the induced AC power generated by the primary auxiliary winding based on the first alternating magnetic field can be converted into induced DC power, and output to the first end of the energy storage capacitor E2, so that the first end of the energy storage capacitor E2 reaches a first voltage, that is, a clamping voltage. For example, when the first end of the primary auxiliary winding is the inductive positive terminal, the fourth auxiliary switch tube Q3 is turned on, so that the tap end of the primary auxiliary winding is the positive electrode, and when the second end of the primary auxiliary winding is the inductive positive terminal, the third auxiliary switch tube Q4 is turned on, so that the tap end of the primary auxiliary winding is still the positive electrode. Thus, the tap end of the primary auxiliary winding outputs the inductive DC energy to the first end of the energy storage capacitor E2.

[0093] On the contrary, when the first end of the energy storage capacitor E2 outputs peak electrical energy to the tap end of the primary auxiliary winding, the third auxiliary switch tube Q4 and the fourth auxiliary switch tube Q3 are alternately turned on under the control of the third control signal and the fourth control signal, respectively, so that the peak electrical energy alternately flows through the primary auxiliary winding and generates a second alternating magnetic field synchronized with the first alternating magnetic field.

[0094] Embodiment five:

[0095] Please refer to Figure 6 In this embodiment, a DC power supply simulation load is provided, and the DC power supply simulation load includes any active clamping converter 60 of any one of Embodiments 1 to 4.

[0096] In some embodiments, the DC power supply simulation load also includes a controller 70 and a rectifier circuit 80. The controller is used to output a control signal to control the active clamp converter 60 to perform voltage conversion, such as outputting a first control signal, a second control signal, a third control signal, a fourth control signal, a fifth control signal and a sixth control signal to respectively control the first auxiliary switch tube Q3, the second auxiliary switch tube Q4, the third auxiliary switch tube Q4, the fourth auxiliary switch tube Q3, the first main switch tube Q1 and the second main switch tube Q2. The rectifier circuit 80 is used to rectify the output power output by the active clamp converter to obtain DC output power. For example, the rectifier circuit 80 can be a rectifier bridge circuit composed of four diodes, or a half-bridge or full-bridge rectifier circuit. In some embodiments, a load (RL) and a filter capacitor E3 can also be connected in parallel between the two ends of the rectifier circuit 80.

[0097] The above specific examples are used to illustrate the present application, which is only used to help understand the present application and is not intended to limit the present application. For technicians in the technical field to which the present application belongs, they can also make some simple deductions, deformations or substitutions based on the ideas of the present application.

Claims

1. An active clamp converter, characterized in that: include: A transformer having a primary winding, a secondary winding and a primary auxiliary winding; a DC power input circuit, whose input end is used to input DC power and whose output end is used to output the DC power to the primary winding; a main switch circuit connected to the primary winding to control the DC power to flow through the primary winding so that the primary winding generates a first alternating magnetic field based on the DC power; an auxiliary switch circuit connected to the primary auxiliary winding, and configured to convert the induced AC power into induced DC power when the primary auxiliary winding generates induced AC power based on the first alternating magnetic field; A clamped energy storage circuit, wherein the clamped end is used to receive the induced DC power, and the peak absorption end is used to connect the primary winding; the clamped end of the clamped energy storage circuit reaches a first voltage based on the induced DC power, wherein the number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, so that the first voltage is greater than the second voltage generated by the two ends of the primary winding based on the DC power; wherein the clamped energy storage circuit comprises an energy storage circuit and a clamped circuit, the first end of the energy storage circuit is used to receive the induced DC power, and the second end is grounded; the energy storage circuit stores energy based on the induced DC power and makes its first end reach the first voltage; the first end and the second end of the clamped circuit are respectively used to connect the two ends of the primary winding, and the third end is connected to the first end of the energy storage circuit; the clamped circuit is used to be turned on when the peak voltage at the two ends of the primary winding is greater than the first voltage, so that the energy storage circuit absorbs the peak power exceeding the first voltage in the peak voltage; When the peak voltage generated by the primary winding based on the leakage inductance is greater than the first voltage, the clamping tank circuit absorbs the peak electric energy of the peak voltage exceeding the first voltage to the clamping end, and the auxiliary switch circuit is further used to control the peak electric energy to flow through the primary auxiliary winding, so that the primary auxiliary winding generates a second alternating magnetic field synchronized with the first alternating magnetic field based on the peak electric energy; The secondary winding generates output electrical energy based on the first alternating magnetic field and the second alternating magnetic field; The auxiliary switch circuit includes a first auxiliary switch tube, a second auxiliary switch tube, a first capacitor and a second capacitor; the first end of the first auxiliary switch tube is connected to the first end of the primary auxiliary winding through the first capacitor, and the second end is respectively connected to the first end of the second auxiliary switch tube and the second end of the primary auxiliary winding, and the second end of the second auxiliary switch tube is connected to the first end of the primary auxiliary winding through the second capacitor; the node between the first auxiliary switch tube and the first capacitor is connected to the clamping end of the clamping tank circuit, and the node between the second auxiliary switch tube and the second capacitor is grounded; The control end of the first auxiliary switch tube is used to input a first control signal, and the control end of the second auxiliary switch tube is used to input a second control signal. The first auxiliary switch tube and the second auxiliary switch tube are alternately turned on under the control of the first control signal and the second control signal, respectively, to convert the induced AC power into induced DC power, and control the peak power to flow through the primary auxiliary winding alternately in different directions.

2. An active clamp converter, characterized in that: include: A transformer having a primary winding, a secondary winding and a primary auxiliary winding; a DC power input circuit, whose input end is used to input DC power and whose output end is used to output the DC power to the primary winding; a main switch circuit connected to the primary winding to control the DC power to flow through the primary winding so that the primary winding generates a first alternating magnetic field based on the DC power; an auxiliary switch circuit connected to the primary auxiliary winding, and configured to convert the induced AC power into induced DC power when the primary auxiliary winding generates induced AC power based on the first alternating magnetic field; A clamped energy storage circuit, wherein the clamped end is used to receive the induced DC power, and the peak absorption end is used to connect the primary winding; the clamped end of the clamped energy storage circuit reaches a first voltage based on the induced DC power, wherein the number of turns of the primary auxiliary winding is greater than the number of turns of the primary winding, so that the first voltage is greater than the second voltage generated by the two ends of the primary winding based on the DC power; wherein the clamped energy storage circuit comprises an energy storage circuit and a clamped circuit, the first end of the energy storage circuit is used to receive the induced DC power, and the second end is grounded; the energy storage circuit stores energy based on the induced DC power and makes its first end reach the first voltage; the first end and the second end of the clamped circuit are respectively used to connect the two ends of the primary winding, and the third end is connected to the first end of the energy storage circuit; the clamped circuit is used to be turned on when the peak voltage at the two ends of the primary winding is greater than the first voltage, so that the energy storage circuit absorbs the peak power exceeding the first voltage in the peak voltage; When the peak voltage generated by the primary winding based on the leakage inductance is greater than the first voltage, the clamping tank circuit absorbs the peak electric energy of the peak voltage exceeding the first voltage to the clamping end, and the auxiliary switch circuit is further used to control the peak electric energy to flow through the primary auxiliary winding, so that the primary auxiliary winding generates a second alternating magnetic field synchronized with the first alternating magnetic field based on the peak electric energy; The secondary winding generates output electrical energy based on the first alternating magnetic field and the second alternating magnetic field; The primary auxiliary winding has a first end, a second end, and a tap end arranged between the first end and the second end, and the tap end is connected to the clamp end of the clamp tank circuit; the auxiliary switch circuit includes a third auxiliary switch tube and a fourth auxiliary switch tube; The first end of the third auxiliary switch tube is connected to the first end of the primary auxiliary winding, the first end of the fourth auxiliary switch tube is connected to the second end of the primary auxiliary winding, and the second end of the third auxiliary switch tube and the second end of the fourth auxiliary switch tube are grounded respectively; The control end of the third auxiliary switch tube is used to input a third control signal, and the control end of the fourth auxiliary switch tube is used to input a fourth control signal. The third auxiliary switch tube and the fourth auxiliary switch tube are alternately turned on under the control of the third control signal and the fourth control signal, respectively, to convert the induced AC power energy into induced DC power energy, and control the peak power energy to flow through the primary auxiliary winding alternately in different directions.

3. The active clamp converter according to claim 1 or 2, characterized in that: The clamping circuit includes a first diode and a second diode, and the energy storage circuit includes an energy storage capacitor; The positive electrode of the first diode and the positive electrode of the second diode are respectively connected to the two ends of the primary winding, the negative electrode of the first diode and the negative electrode of the second diode are both connected to the first end of the energy storage capacitor, and the second end of the energy storage capacitor is grounded; The first diode and the second diode are both used for conducting when the peak voltage at the anode thereof is greater than the first voltage, so that the energy storage capacitor absorbs the peak electrical energy of the peak voltage exceeding the first voltage.

4. The active clamp converter according to claim 1 or 2, characterized in that: The main switch circuit includes a first main switch tube and a second main switch tube; The first end of the first main switch is connected to the first end of the primary winding, the first end of the second main switch is connected to the second end of the primary winding, and the second end of the first main switch and the second end of the second main switch are grounded respectively; The control end of the first main switch tube is used to input a fifth control signal, and the control end of the second main switch tube is used to input a sixth control signal. The first main switch tube and the second main switch tube are alternately turned on under the control of the fifth control signal and the sixth control signal, respectively, to control the DC power to flow through the primary winding alternately in different directions.

5. The active clamp converter according to claim 1 or 2, characterized in that: The DC power input circuit is also used to boost the DC power and output it to the primary winding.

6. The active clamp converter according to claim 5, characterized in that: The DC power input circuit includes a third capacitor, a first inductor and a second inductor; The first ends of the first inductor and the second inductor are respectively used to input the DC power, the second end of the first inductor is connected to the first end of the primary winding, and the second end of the second inductor is connected to the second end of the primary winding; The first end of the third capacitor is used to input the DC power, and the second end is grounded; The first inductor and the second inductor are used to alternately store energy when the main switch circuit controls the DC power to flow through the primary winding, and based on the stored energy, the DC power is alternately boosted and output to the primary winding; the third capacitor is used to filter the DC power.

7. The active clamp converter according to claim 5, characterized in that: The primary winding has a first end, a second end, and a tap end arranged between the first end and the second end; the DC power input circuit includes a third capacitor and a third inductor; The first end of the third inductor is used to input the DC power, and the second end is connected to the tap end of the primary winding; the first end of the third capacitor is used to input the DC power, and the second end is grounded; The third inductor is used to store energy when the first end and the second end of the primary winding are both grounded, and based on the stored energy, when the main switch circuit controls the DC power to flow through the primary winding, the DC power is boosted and output to the primary winding; the third capacitor is used to filter the DC power.

8. A DC power supply simulated load, characterized in that: It comprises the active clamped converter as claimed in any one of claims 1 to 7.

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