Totem-pole bridgeless circuit and power module

Abstract

The embodiment of the present application relates to the field of power electronics, in particular to a totem pole bridgeless circuit and a power module, the circuit comprising an AC input unit, a first bridge arm unit, a second bridge arm unit, a DC output unit, a current mutual inductance unit and a control unit. The current mutual inductance unit comprises a first mutual inductor circuit and a second mutual inductor circuit, the first mutual inductor circuit and a first switch tube being connected in series between a first series connection point and a first parallel node, the second mutual inductor circuit and a second switch tube being connected in series between the first series connection point and a second parallel node, a current sampling end of the control unit being connected with an output end of the current mutual inductance unit, an enable end of the control unit being connected with the first mutual inductor circuit and the second mutual inductor circuit, so as to enable the current mutual inductance unit to sample current, to adjust the on-off and duty cycle of the first switch tube and the second switch tube in the first bridge arm unit, and the totem pole bridgeless circuit has the advantages of simple structure, low cost, small size and high reliability.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a totem pole bridgeless circuit and power supply module. Background Technology

[0002] In energy conversion systems, power conversion efficiency is a crucial parameter for evaluating the system. Compared to traditional power conversion circuits, bridgeless circuits can eliminate some or all diodes, thereby reducing circuit conduction losses and offering advantages in high-efficiency energy conversion. Wide-bandgap power semiconductors, such as gallium nitride (GaN) and silicon carbide (SiC), have recently gained favor in power conversion applications due to their excellent switching characteristics and continuously improving quality. Benefiting from the advantages of gallium nitride and silicon carbide, as well as the advantages of bridgeless circuits, totem-pole bridgeless circuits, as a type of bridgeless circuit, possess advantages such as simple circuit structure and high conversion efficiency, and have been increasingly widely used in recent years.

[0003] In implementing the embodiments of the present invention, the inventors discovered at least the following problems in the above-mentioned related technologies: Currently, current sampling in totem pole bridgeless circuits mainly adopts two methods. The first method is to directly sample the inductor current through a Hall sensor, and the second method is to use a combination of sampling resistor and signal amplification and isolation circuit. In the first method, the sensor is expensive and bulky; in the second method, the circuit is complex and costly. Summary of the Invention

[0004] This application provides a totem pole bridgeless circuit and power supply module with simple circuit structure, low cost and strong anti-interference ability.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] To address the aforementioned technical problems, in a first aspect, embodiments of the present invention provide a totem pole bridgeless circuit, comprising: a first bridge arm unit, including a first switch and a second switch connected in series in the same direction, wherein the connection point between the first switch and the second switch is a first series connection point; a second bridge arm unit, connected in parallel with the first bridge arm unit, wherein the second bridge arm unit further includes a second series connection point, the connection point between the second bridge arm unit and the first switch is a first parallel connection point, and the connection point between the second bridge arm unit and the second switch is a second parallel connection point; and an AC input unit, the output terminal of which is connected to the first series connection point and the second series connection point respectively. The system includes: a DC output unit connected in parallel with the first bridge arm unit and the second bridge arm unit; a current transformer unit comprising a first transformer circuit and a second transformer circuit, wherein the first transformer circuit and the first switch are connected in series between the first series connection point and the first parallel connection point, and the second transformer circuit and the second switch are connected in series between the first series connection point and the second parallel connection point; and a control unit whose current sampling terminal is connected to the output terminal of the current transformer unit, and whose enable terminal is connected to the first transformer circuit and the second transformer circuit, for enabling the current transformer unit to sample current in order to adjust the on / off state and duty cycle of the first switch and the second switch.

[0007] In some embodiments, the second bridge arm unit includes a first diode and a second diode connected in series in the same direction. The connection point between the first diode and the second diode is the second series connection point. The anode of the first diode is connected to the first switching transistor, and the cathode of the first diode is connected to the output terminal of the AC input unit. The anode of the second diode is connected to the output terminal of the AC input unit, and the anode of the second diode is connected to the cathode of the first diode. The cathode of the second diode is connected to the second current transformer circuit.

[0008] In some embodiments, the first current transformer circuit includes: a third diode, the cathode of which is connected to the sampling terminal of the control unit; a first current transformer, the primary winding of which is connected in series with the first switching transistor between the first series connection point and the first parallel connection point; one end of the secondary winding of which is connected to the anode of the third diode; the other end of the secondary winding of which is grounded; and a first current transformer control circuit, which is connected in parallel across the two ends of the secondary winding of the first current transformer, and whose control terminal is connected to the enable terminal of the control unit. The second current transformer circuit includes: a fourth diode, the cathode of which is connected to the sampling terminal of the control unit; a second current transformer, the primary winding of which is connected in series with the second switching transistor between the first series connection point and the second parallel connection point; one end of the secondary winding of which is connected to the anode of the fourth diode; the other end of the secondary winding of which is grounded; and a second current transformer control circuit, which is connected in parallel across the two ends of the secondary winding of the second current transformer, and whose control terminal is connected to the enable terminal of the control unit.

[0009] In some embodiments, the first mutual inductance control circuit and the second mutual inductance control circuit have the same structure, and both the first mutual inductance control circuit and the second mutual inductance control circuit include: a third switch and a fourth switch connected in reverse series, wherein the non-connected end of the third switch is connected to one end of the secondary winding of the first or second mutual inductor, and the non-connected end of the fourth switch is connected to the other end of the secondary winding of the first or second mutual inductor; and a fifth switch, the input terminal of which is connected to the control terminal of the third switch, the output terminal of which is connected to the non-connected end of the fourth switch, and the control terminal of which is connected to the control terminal of the second mutual inductor. The unit's enable terminal is connected to: a first resistor, one end of which is connected to the series connection point between the third and fourth switching transistors, and the other end of which is connected to the control terminal of the third switching transistor; a second resistor, one end of which is connected to the series connection point between the third and fourth switching transistors, and the other end of which is connected to the control terminal of the fourth switching transistor; a third resistor, one end of which is connected to the power supply, and the other end of which is connected to the control terminal of the third switching transistor; a fifth diode, the anode of which is connected to the control terminal of the fourth switching transistor, and the cathode of which is grounded; and a level conversion capacitor, one end of which is connected to the control terminal of the fourth switching transistor, and the other end of which is connected to the control unit.

[0010] In some embodiments, the third switch is an N-type field-effect transistor (FET), the fourth switch is a P-type FET, the source of the third switch is connected to the source of the fourth switch, the drain of the third switch is the end of the third switch that is not connected in series and is connected to one end of the secondary winding of the first or second current transformer, the drain of the fourth switch is the end of the fourth switch that is not connected in series and is connected to the other end of the secondary winding of the first or second current transformer, and the gate of the third switch and the gate of the fourth switch are respectively connected to the enable terminal of the control unit.

[0011] In some embodiments, the current transformer unit further includes a sampling resistor, one end of which is connected to the output terminal of the first transformer circuit, the output terminal of the second transformer circuit, and the current sampling terminal of the control unit, and the other end of which is grounded.

[0012] In some embodiments, the input terminal of the AC input unit is connected to an AC power supply. The AC input unit includes an input inductor, one end of which is connected to one end of the AC power supply, and the other end of which is connected between the second switching transistor and the first current transformer circuit. The other end of the AC power supply is connected to the second series connection point.

[0013] In some embodiments, the control unit further includes: a first voltage sampling terminal, which is connected to both ends of the AC power supply via an amplifier, for acquiring the input voltage of the totem pole bridgeless circuit; a second voltage sampling terminal, which is connected to the output terminal of the second bridge arm unit, for acquiring the output voltage of the totem pole bridgeless circuit; the control unit is also used to adjust the on / off state and duty cycle of the first switch and the second switch according to the input voltage and the output voltage.

[0014] In some embodiments, the DC output unit includes: a load capacitor connected in parallel with the output terminal of the second bridge arm unit; and a load resistor connected in parallel with the load capacitor.

[0015] To address the aforementioned technical problems, in a second aspect, this invention provides a power module comprising: a totem pole bridgeless circuit as described in the first aspect.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: Unlike the prior art, the embodiments of the present invention provide a totem pole bridgeless circuit and power supply module. The circuit includes a first bridge arm unit, a second bridge arm unit, an AC input unit, a DC output unit, a current transformer unit, and a control unit. The current transformer unit includes a first transformer circuit and a second transformer circuit. The first transformer circuit and a first switch are connected in series between a first series connection point and a first parallel connection point. The second transformer circuit and the second switch are connected in series between the first series connection point and the second parallel connection point. The current sampling terminal of the control unit is connected to the output terminal of the current transformer unit, and the enable terminal of the control unit is connected to the first transformer circuit and the second transformer circuit, enabling the current transformer unit to sample the current to adjust the on / off state and duty cycle of the first and second switches in the first bridge arm unit. The totem pole bridgeless circuit has a simple structure and has the advantages of low cost, small size, and high reliability. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements / modules with the same reference numerals in the drawings are represented as similar elements / modules. Unless otherwise stated, the figures in the drawings do not constitute a limitation on scale.

[0018] Figure 1 This is a structural block diagram of a totem pole bridgeless circuit provided in Embodiment 1 of the present invention;

[0019] Figure 2 This is a circuit structure diagram of a totem pole bridgeless circuit provided in Embodiment 1 of the present invention;

[0020] Figure 3 yes Figure 2 The diagram shows the circuit structure of the first mutual inductance control circuit or the second mutual inductance control circuit in the totem pole bridgeless circuit.

[0021] Figure 4(a) is Figure 2 The diagram shows the energy storage circuit of the totem pole bridgeless circuit during the positive half-cycle of AC power input.

[0022] Figure 4(b) is Figure 2 The diagram shows the freewheeling circuit of the totem pole bridgeless circuit during the positive half-cycle of AC power input.

[0023] Figure 4(c) is Figure 2 The diagram shows the energy storage circuit of the totem pole bridgeless circuit when the AC power input is in the negative half-cycle of AC power.

[0024] Figure 4(d) is Figure 2 The diagram shows the freewheeling circuit of the totem pole bridgeless circuit when the AC power input is in the negative half-cycle of AC.

[0025] Figure 5 This is a schematic diagram of the hardware structure of a power supply module provided in Embodiment 2 of the present invention.

[0026] Figure Descriptions: 100, Totem Pole Bridgeless Circuit; 110, First Bridge Arm Unit; 120, Second Bridge Arm Unit; 130, AC Input Unit; 140, Current Transformer Unit; 141, First Current Transformer Circuit; 141a, First Current Transformer Control Circuit; 142, Second Current Transformer Circuit; 142a, Second Current Transformer Control Circuit; 150, Control Unit; 160, DC Output Unit; P1, First Series Connection Point; P2, Second Series Connection Point; P3, First Parallel Connection Point; P4, Second Parallel Connection Point; AC1, AC Power Supply; L1, Input Inductor; Q1, First Switch; Q2, Second Switch; Q3, Third Switch; Q4, Fourth Switch; Q5, Fifth Switch; D1, First Diode; D2, Second Diode; D3, Third Diode D4, fourth diode; D5, fifth diode; CT1, first current transformer; CT2, second current transformer; R1, first resistor; R2, second resistor; R3, third resistor; RS, sampling resistor; RL, load resistor; C1, load capacitor; C2, level conversion capacitor; VCC, power supply; U1A, amplifier; Vcs, sampling terminal of control unit; CT1_EN / CT2_EN, enable terminal of control unit (control terminal of first current transformer control circuit / control terminal of second current transformer control circuit); GATE_Q1 / GATE_Q2, output terminal of control unit (control terminal of first switching transistor / control terminal of second switching transistor); Vac, first voltage sampling terminal of control unit; Vout, second voltage sampling terminal of control unit; 10, power supply module. Detailed Implementation

[0027] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0029] It should be noted that, unless there is a conflict, the various features in the embodiments of this invention can be combined with each other, all of which are within the protection scope of this application. Furthermore, although functional modules are divided in the device schematic diagram, in some cases, the module division may differ from that in the device. In addition, the terms "first," "second," and "third" used herein do not limit the data or execution order, but only distinguish identical or similar items with substantially the same function and effect. It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there may be one or more intermediate elements between them.

[0030] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0031] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] To address the issues of high cost, large size, and high power loss in existing totem pole bridgeless circuits, this invention provides a totem pole bridgeless circuit and power supply module. This circuit achieves current sampling by setting a simple current inductor unit. The control unit can then adjust the on / off state and duty cycle of the first and second switches in the first bridge arm unit based on the sampled current to achieve functions such as power modulation and circuit protection.

[0033] Specifically, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0034] Example 1

[0035] This invention provides a totem pole bridgeless circuit; please refer to [link / reference]. Figure 1 The diagram shows a structural block diagram of a totem pole bridgeless circuit provided in an embodiment of the present invention. The totem pole bridgeless circuit 100 includes: a first bridge arm unit 110, a second bridge arm unit 120, an AC input unit 130, a current inductor unit 140, a control unit 150, and a DC output unit 160.

[0036] The first bridge arm unit 110 includes a first switch Q1 and a second switch Q2 connected in the same direction, and the connection point between the first switch Q1 and the second switch Q2 is a first series connection point P1. Please refer to [further details omitted]. Figure 2This illustration shows the circuit structure of a totem pole bridgeless circuit 100 provided by an embodiment of the present invention. The control terminal of the first switch Q1 is connected to the output terminal GATE_Q1 of the control unit 150, and the control terminal of the second switch Q2 is connected to the output terminal GATE_Q2 of the control unit 150. The control unit 150 controls the on / off state of the first switch Q1 and the second switch Q2, as well as the duty cycle of the drive signal, through the drive signals output from the output terminals GATE_Q1 and GATE_Q2. For example, the active transistor in the first switch Q1 and the freewheeling transistor in the second switch Q2 can be turned on and turned off according to the working cycle; or, the first switch Q1 and the second switch Q2 can be turned off to achieve protection when a peak current is detected; or, the duty cycle of the drive signal can be adjusted according to the collected current data to adjust the output power of the circuit, etc. The specific design can be carried out by software design according to actual needs. The drive signal can be a pulse width modulation (PWM) signal.

[0037] The second bridge arm unit 120 is connected in parallel with the first bridge arm unit 110, and includes a second series connection point P2. The connection point between the second bridge arm unit 120 and the first switch Q1 is a first parallel connection point P3, and the connection point between the second bridge arm unit 120 and the second switch Q2 is a second parallel connection point P4. For details, please refer to [link to relevant documentation]. Figure 2 The second bridge arm unit 120 includes a first diode D1 and a second diode D2 connected in series in the same direction. The connection point between the first diode D1 and the second diode D2 is the second series connection point P2. The anode of the first diode D1 is connected to the first switching transistor Q1, and the cathode of the first diode D1 is connected to the output terminal of the AC input unit 130. The anode of the second diode D2 is connected to both the output terminal of the AC input unit 130 and the anode of the first diode D1, and the cathode of the second diode D2 is connected to the second current transformer circuit 142. It should be noted that... Figure 2 The second bridge arm unit 120 uses two diodes connected in series as an example of a bridge arm. The two diodes can also be replaced by switching transistors and operate in synchronous rectifier mode.

[0038] The output terminals of the AC input unit 130 are respectively connected to the first series connection point P1 and the second series connection point P2; for details, please refer to [link to relevant documentation]. Figure 2The input terminal of the AC input unit 130 is connected to the AC power supply AC1. The AC input unit 130 includes an input inductor L1, one end of which is connected to one end of the AC power supply AC1, and the other end of which is connected between the second switch Q2 and the first transformer circuit 141. The other end of the AC power supply AC1 is connected to the second series connection point P2.

[0039] The current transformer unit 140 includes a first transformer circuit 141 and a second transformer circuit 142. The first transformer circuit 141 and the first switching transistor Q1 are connected in series between the first series connection point P1 and the first parallel connection point P3. The second transformer circuit 142 is connected in series between the first series connection point P1 and the second parallel connection point P4. The first transformer circuit 141 is used to collect the current flowing through the first switching transistor Q1 as the active transistor when the AC voltage output by the AC power supply AC1 is in the positive half-wave, and not to collect the current flowing through the first switching transistor Q1 as the freewheeling transistor when the AC voltage is in the negative half-wave. Whether to collect the current can be controlled by the signal output by the enable terminal CT1_EN of the control unit 150. The second current transformer circuit 142 is used to collect the current flowing through the second switching transistor Q2 as the active transistor when the AC voltage output by the AC power supply AC1 is in the negative half-wave, and not to collect the current flowing through the second switching transistor Q2 as the freewheeling transistor when the AC voltage is in the positive half-wave. Whether to collect the current can be controlled by the signal output by the enable terminal CT2_EN of the control unit 150.

[0040] For details, please continue to see Figure 2The first current transformer circuit 141 includes: a third diode D3, the cathode of which is connected to the sampling terminal Vcs of the control unit 150; a first current transformer CT1, the primary winding of which is connected in series with the first switching transistor Q1 between the first series connection point P1 and the first parallel connection point P3; one end of the secondary winding of which is connected to the anode of the third diode D3; and the other end of the secondary winding of which is grounded; and a first current transformer control circuit 141a, which is connected in parallel across the two ends of the secondary winding of the first current transformer CT1, and whose control terminal is connected to the enable terminal CT1_EN of the control unit 150. The second current transformer circuit 142 includes: a fourth diode D4, whose cathode is connected to the sampling terminal Vcs of the control unit 150; a second current transformer CT2, whose primary winding is connected in series with the second switching transistor Q2 between the first series connection point P1 and the second parallel connection point P4; one end of its secondary winding is connected to the anode of the fourth diode D4; and the other end of its secondary winding is grounded; and a second current transformer control circuit 142a is connected in parallel across the two ends of the secondary winding of the second current transformer CT2, and its control terminal is connected to the enable terminal CT2_EN of the control unit 150.

[0041] Further, please see Figure 3 It shows Figure 2 The circuit structure of the first mutual inductance control circuit 141a or the second mutual inductance control circuit 142a in the totem pole bridgeless circuit 100 shown is as follows: Figure 3 Port 1, port 2, and port 3 in the code are respectively connected to... Figure 2 Ports 1, 2, and 3 of the first mutual inductance control circuit 141a or the second mutual inductance control circuit 142a correspond to each other.

[0042] like Figure 3As shown, the first mutual inductance control circuit 141a and the second mutual inductance control circuit 142a have the same structure, and both the first mutual inductance control circuit 141a and the second mutual inductance control circuit 142a include: a third switch Q3 and a fourth switch Q4 connected in reverse series, the non-connected end of the third switch Q3 is connected to one end of the secondary winding of the first mutual inductor CT1 or the second mutual inductor CT2, and the non-connected end of the fourth switch Q4 is connected to the other end of the secondary winding of the first mutual inductor CT1 or the second mutual inductor CT2; a fifth switch Q5, the input end of which is connected to the control terminal of the third switch Q3, the output end of which is connected to the non-connected end of the fourth switch Q4, and the control terminal of which is connected to the control unit 150. The following components are connected: CT1_EN / CT2_EN; a first resistor R1, one end of which is connected to the series connection point between the third switch Q3 and the fourth switch Q4, and the other end of which is connected to the control terminal of the third switch Q3; a second resistor R2, one end of which is connected to the series connection point between the third switch Q3 and the fourth switch Q4, and the other end of which is connected to the control terminal of the fourth switch Q4; a third resistor R3, one end of which is connected to the power supply VCC, and the other end of which is connected to the control terminal of the third switch Q3; a fifth diode D5, the anode of which is connected to the control terminal of the fourth switch Q4, and the cathode of which is grounded; and a level conversion capacitor C2, one end of which is connected to the control terminal of the fourth switch Q4, and the other end of which is connected to the control unit 150.

[0043] Wherein, when the third switch Q3 is an N-type field-effect transistor and the fourth switch Q4 is a P-type field-effect transistor, the source of the third switch Q3 is connected to the source of the fourth switch Q4, thereby connecting the anode of the body diode of the third switch Q3 to the anode of the body diode of the fourth switch Q4. The drain of the third switch Q3 is the non-connected end of the third switch Q3 and is connected to one end of the secondary winding of the first current transformer CT1 or the second current transformer CT2. The drain of the fourth switch Q4 is the non-connected end of the fourth switch Q4 and is connected to the other end of the secondary winding of the first current transformer CT1 or the second current transformer CT2. The gate of the third switch Q3 and the gate of the fourth switch Q4 are respectively connected to the enable terminals CT1_EN and CT2_EN of the control unit 150.

[0044] Furthermore, the fifth switch Q5 is used to implement logic inversion and level conversion, capable of converting a 3.3V or 5V level to a higher level, such as 12V. The gate of the fourth switch Q4 is driven by a level conversion circuit composed of a level conversion capacitor C2 and a fifth diode D5. This level conversion circuit converts a positive level signal into a negative level signal, which is used to drive the fourth switch Q4 to turn on and off.

[0045] It should be noted that during power-on, the totem pole bridgeless circuit 100 needs to pre-charge the level conversion capacitor C2 by outputting a high-level pulse signal through the enable terminals CT1_EN / CT2_EN before starting operation. This ensures that the gate of the fourth switch Q4 is at a negative level after power-on, allowing the fourth switch Q4 to enter the on state. Specifically, when the AC power supply AC1 is powered on during the positive half-cycle, the first switch Q1 is the active switch and the second switch Q2 is the freewheeling switch. In this case, a high-level pulse signal needs to be output through the enable terminal CT2_EN to pre-charge the level conversion capacitor C2 in the second mutual inductance control circuit 142a. Conversely, when the AC power supply AC1 is powered on during the negative half-cycle, the second switch Q2 is the active switch and the first switch Q1 is the freewheeling switch. In this case, a high-level pulse signal needs to be output through the enable terminal CT1_EN to pre-charge the level conversion capacitor C2 in the first mutual inductance control circuit 141a.

[0046] Further reading is available upon request. Figure 2 The current transformer unit 140 further includes a sampling resistor RS, one end of which is connected to the output terminal of the first transformer circuit, the output terminal of the second transformer circuit, and the current sampling terminal of the control unit, respectively, and the other end of which is grounded. After the output terminals of the first transformer circuit 141 and the second transformer circuit 142 are connected together, they are connected to the sampling resistor RS, thereby outputting a current sampling signal to the control unit 150.

[0047] The control unit 150 has its current sampling terminal Vcs connected to the output terminal of the current transformer unit 140, and its enable terminal CT1_EN / CT2_EN connected to the first transformer circuit 141 and the second transformer circuit 142. It is used to enable the current transformer unit 140 to sample the current in order to adjust the on / off state and duty cycle of the first switch Q1 and the second switch Q2, thereby realizing the control of the entire totem pole bridgeless circuit 100.

[0048] Further reading is available upon request. Figure 2The control unit 150 may further include: a first voltage sampling terminal Vac, which is connected to both ends of the AC power supply AC1 through an amplifier U1A, for acquiring the input voltage of the totem pole bridgeless circuit 100; a second voltage sampling terminal Vout, which is connected to the output terminal of the second bridge arm unit 120, for acquiring the output voltage of the totem pole bridgeless circuit 100; the control unit 150 is also used to adjust the on / off and duty cycle of the first switch Q1 and the second switch Q2 according to the input voltage and the output voltage.

[0049] The DC output unit 160 is connected in parallel with the first bridge arm unit 110 and the second bridge arm unit 120; specifically, please refer to [link to relevant documentation]. Figure 2 The DC output unit 160 includes: a load capacitor C1, which is connected in parallel with the output terminal of the second bridge arm unit 120; and a load resistor RL, which is connected in parallel with the load capacitor C1.

[0050] It should be noted that, in Figure 2 In the example shown, the first switch Q1, the second switch Q2, the third switch Q3, and the fifth switch Q5 are N-channel metal-oxide-semiconductor field-effect transistors (MOSFETs), and the fourth switch Q4 is a P-channel MOSFET. In practical applications, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, and the fifth switch Q5 can also be other types of transistors such as triodes, bipolar junction transistors (BJTs), junctiongate field-effect transistors (JFETs), and vertical metal-oxide-semiconductor (VMOS), depending on the specific requirements.

[0051] When the totem pole bridgeless circuit 100 provided in this embodiment of the invention operates during the positive half-cycle of the AC power supply AC1, the first switching transistor Q1 is the active transistor, and the second switching transistor Q2 is the freewheeling transistor, operating in a complementary on-state. The first current transformer CT1 remains enabled, and the second current transformer CT2 remains off. The energy storage circuit of the totem pole bridgeless circuit 100 at this time is shown in Figure 4(a), and the freewheeling circuit of the totem pole bridgeless circuit 100 is shown in Figure 4(b). Specifically,

[0052] As shown in Figure 4(a), when the first switch Q1 is turned on, current flows through the positive terminal of AC power supply AC1 to the input inductor L1, the first current transformer CT1, the first switch Q1, the first diode D1, and then back to the negative terminal of AC power supply AC1. At this time, the input inductor L1 is in an energy storage state, and AC power supply AC1 stores energy in the input inductor L1. A positive current flows through the primary winding of the first current transformer CT1, and a positive current also flows through the secondary winding of the first current transformer CT1. The secondary winding of the first current transformer CT1, the third diode D3, and the sampling resistor RS form a rectifier circuit to collect the positive current signal. At this time, the second switch Q2 is turned off. Simultaneously, the load capacitor C1 discharges through the load resistor RL.

[0053] As shown in Figure 4(b), when the first switch Q1 is turned off, no current flows through the primary winding of the first current transformer CT1. At this time, the second switch Q2 is turned on, and the current flows through the positive terminal of the AC power supply AC1 to the input inductor L1, the second switch Q2, the second current transformer CT2, the DC output unit 160, the first diode D1, and then back to the negative terminal of the AC power supply AC1. The secondary winding of the second current transformer CT2 is short-circuited by the low-level signal output by the control unit 150, and cannot sample the current signal. The input inductor L1 operates in the energy release state, releasing energy to the load resistor RL, and the load capacitor C1 operates in the charging state.

[0054] When the totem pole bridgeless circuit 100 provided in this embodiment of the invention operates during the negative half-cycle of the AC power supply AC1, the second switch Q2 is the active switch, and the first switch Q1 is the freewheeling switch, operating in a complementary on-state. The second current transformer CT2 remains enabled, and the first current transformer CT1 remains off. The energy storage circuit of the totem pole bridgeless circuit 100 at this time is shown in Figure 4(c), and the freewheeling circuit of the totem pole bridgeless circuit 100 is shown in Figure 4(d). Specifically,

[0055] As shown in Figure 4(c), when the second switch Q2 is turned on, current flows through the positive terminal of AC power supply AC1 to the second diode D2, the second current transformer CT2, the second switch Q2, the input inductor L1, and then back to the negative terminal of AC power supply AC1. Input inductor L1 operates in an energy storage state, and AC power supply AC1 stores energy in input inductor L1. A positive current flows through the primary winding of the second current transformer CT2, and a positive current also flows through the secondary winding of the second current transformer CT2. Therefore, the secondary winding of the second current transformer CT2, the fourth diode D4, and the sampling resistor RS form a rectifier circuit to collect the positive current signal. Simultaneously, the load capacitor C1 discharges through the load resistor RL.

[0056] As shown in Figure 4(d), when the second switch Q2 is turned off, no current flows through the primary winding of the second current transformer CT2. At this time, the first switch Q1 is turned on, and the current flows through the positive terminal of the AC power supply AC1 to the second diode D2, the DC output unit 160, the first switch Q1, the first current transformer CT1, the input inductor L1, and then back to the negative terminal of the AC power supply AC1. The secondary side of the first current transformer CT1 is short-circuited by the low-level signal output by the control unit 150, and cannot sample the current signal. The input inductor L1 operates in the energy release state, releasing energy to the load unit RL, and the load capacitor C1 operates in the charging state.

[0057] Example 2

[0058] This invention provides a power supply module; please refer to [link / reference]. Figure 5 This illustrates the hardware structure of a power module provided in an embodiment of the present invention. The power module 10 includes a totem pole bridgeless circuit 100 as described in Embodiment 1.

[0059] In energy conversion systems, such as power module 10, the totem pole bridgeless circuit 100 provided in Embodiment 1 of the present invention can be used to achieve current sampling by using only a low-cost current transformer and peripheral circuits. The current sampling circuit is low in cost, small in size, and the current data collected is highly reliable.

[0060] This invention provides a totem pole bridgeless circuit and power supply module. The circuit includes a first bridge arm unit, a second bridge arm unit, an AC input unit, a DC output unit, a current transformer unit, and a control unit. The current transformer unit includes a first transformer circuit and a second transformer circuit. The first transformer circuit and a first switch are connected in series between a first series connection point and a first parallel connection point. The second transformer circuit and the second switch are connected in series between a second series connection point and a second parallel connection point. The current sampling terminal of the control unit is connected to the output terminal of the current transformer unit, and the enable terminal of the control unit is connected to the first transformer circuit and the second transformer circuit, enabling the current transformer unit to sample the current to adjust the on / off state and duty cycle of the first and second switches in the first bridge arm unit. This totem pole bridgeless circuit has a simple structure and advantages such as low cost, small size, and high reliability.

[0061] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A totem pole bridgeless circuit, characterized in that, include: The first bridge arm unit includes a first switch and a second switch connected in series in the same direction, and the connection point between the first switch and the second switch is a first series connection point. The second bridge arm unit is connected in parallel with the first bridge arm unit, and the second bridge arm unit also includes a second series connection point. The connection point between the second bridge arm unit and the first switch is a first parallel connection point, and the connection point between the second bridge arm unit and the second switch is a second parallel connection point. An AC input unit, the output of which is connected to the first series connection point and the second series connection point respectively; A DC output unit is connected in parallel with the first bridge arm unit and the second bridge arm unit; The current transformer unit includes a first transformer circuit and a second transformer circuit. The first transformer circuit and the first switch are connected in series between the first series connection point and the first parallel connection point. The second transformer circuit and the second switch are connected in series between the first series connection point and the second parallel connection point. The control unit has its current sampling terminal connected to the output terminal of the current transformer unit, and its enable terminal connected to the first transformer circuit and the second transformer circuit, for enabling the current transformer unit to sample current in order to adjust the on / off state and duty cycle of the first switch and the second switch.

2. The totem pole bridgeless circuit according to claim 1, characterized in that, The second bridge arm unit includes a first diode and a second diode connected in series in the same direction, and the connection point between the first diode and the second diode is the second series connection point. The anode of the first diode is connected to the first switching transistor, and the cathode of the first diode is connected to the output terminal of the AC input unit. The anode of the second diode is connected to the output terminal of the AC input unit, the anode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode is connected to the second current transformer circuit.

3. The totem pole bridgeless circuit according to claim 1, characterized in that, The first current transformer circuit includes: The third diode has its cathode connected to the sampling terminal of the control unit. The first current transformer has its primary winding connected in series with the first switching transistor between the first series connection point and the first parallel connection point. One end of its secondary winding is connected to the anode of the third diode, and the other end of its secondary winding is grounded. The first mutual inductance control circuit is connected in parallel to both ends of the secondary winding of the first mutual inductor, and its control terminal is connected to the enable terminal of the control unit. The second current transformer circuit includes: The fourth diode has its cathode connected to the sampling terminal of the control unit. The second current transformer has its primary winding connected in series with the second switching transistor between the first series connection point and the second parallel connection point. One end of its secondary winding is connected to the anode of the fourth diode, and the other end of its secondary winding is grounded. The second mutual inductance control circuit is connected in parallel across the two ends of the secondary winding of the second mutual inductor, and its control terminal is connected to the enable terminal of the control unit.

4. The totem pole bridgeless circuit according to claim 3, characterized in that, The first mutual inductance control circuit and the second mutual inductance control circuit have the same structure, and both the first mutual inductance control circuit and the second mutual inductance control circuit include: The third and fourth switches are connected in reverse series, with the non-connected end of the third switch connected to one end of the secondary winding of the first or second current transformer, and the non-connected end of the fourth switch connected to the other end of the secondary winding of the first or second current transformer. The fifth switch has its input terminal connected to the control terminal of the third switch, its output terminal connected to the non-connected end of the fourth switch, and its control terminal connected to the enable terminal of the control unit. The first resistor has one end connected to the series connection point between the third and fourth switching transistors, and the other end connected to the control terminal of the third switching transistor. The second resistor has one end connected to the series connection point between the third and fourth switching transistors, and the other end connected to the control terminal of the fourth switching transistor. The third resistor has one end connected to the power supply and the other end connected to the control terminal of the third switching transistor. The fifth diode has its anode connected to the control terminal of the fourth switching transistor, and its cathode grounded. A level-shifting capacitor, one end of which is connected to the control terminal of the fourth switching transistor, and the other end of which is connected to the control unit.

5. The totem pole bridgeless circuit according to claim 4, characterized in that, The third switching transistor is an N-type field-effect transistor, and the fourth switching transistor is a P-type field-effect transistor. The source of the third switch is connected to the source of the fourth switch. The drain of the third switching transistor is the end that is not connected in series with the third switching transistor, and it is connected to one end of the secondary winding of the first current transformer or the second current transformer. The drain of the fourth switching transistor is the end that is not connected in series with the fourth switching transistor, and is connected to the other end of the secondary winding of the first current transformer or the second current transformer. The gates of the third and fourth switching transistors are respectively connected to the enable terminal of the control unit.

6. The totem pole bridgeless circuit according to any one of claims 1-5, characterized in that, The current transformer unit further includes a sampling resistor, one end of which is connected to the output terminal of the first transformer circuit, the output terminal of the second transformer circuit, and the current sampling terminal of the control unit, and the other end of which is grounded.

7. The totem pole bridgeless circuit according to any one of claims 1-5, characterized in that, The input terminal of the AC input unit is connected to an AC power source, and the AC input unit includes: An input inductor is provided, with one end connected to one end of the AC power supply and the other end connected between the second switching transistor and the first current transformer circuit. The other end of the AC power supply is connected to the second series connection point.

8. The totem pole bridgeless circuit according to claim 7, characterized in that, The control unit further includes: The first voltage sampling terminal is connected to both ends of the AC power supply through an amplifier and is used to collect the input voltage of the totem pole bridgeless circuit. The second voltage sampling terminal is connected to the output terminal of the second bridge arm unit and is used to collect the output voltage of the totem pole bridgeless circuit. The control unit is also used to adjust the on / off state and duty cycle of the first switch and the second switch according to the input voltage and the output voltage.

9. The totem pole bridgeless circuit according to any one of claims 1-5, characterized in that, The DC output unit includes: The load capacitor is connected in parallel with the second bridge arm unit; The load resistor is connected in parallel with the load capacitor.

10. A power supply module, characterized in that, include: The totem pole bridgeless circuit as described in any one of claims 1-9.

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