A totem pole bridgeless circuit and power supply module

Abstract

The present invention provides a totem pole bridgeless circuit and power supply module, comprising an input inductor, a bridge arm unit, a current sampling unit, and a control unit. The first end of the input inductor is connected to the first end of an AC power supply. The current sampling unit is connected between the bridge arm unit and a load, and is used to obtain an output current output by the bridge arm unit to the load. The control unit has a first input end connected to the current sampling unit, a second input end for obtaining an output voltage output by the bridge arm unit to the load, a third input end for obtaining an AC voltage of the AC power supply, and an output end connected to the bridge arm unit. The control unit is used to output the voltage, AC voltage, and output current to obtain an inductor current of the input inductor, and control the bridge arm unit based on the inductor current. The control unit obtains the inductor current of the input inductor based on the input voltage, output current, and output voltage, eliminating the need to directly sample the inductor current of the input inductor, thereby reducing circuit complexity, cost, and size.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of electronic power technology, and in particular to a totem pole bridgeless circuit and a power supply module. Background Art

[0002] In energy conversion systems, power conversion efficiency is crucial. Wide-bandgap power semiconductors, such as gallium nitride (GaN) and silicon carbide (SiC), have recently gained popularity in power conversion applications due to their excellent switching characteristics and continuously improving quality. Thanks to the advantages of GaN and SiC, the totem-pole bridgeless circuit, a type of bridgeless circuit, has become increasingly popular in recent years due to its simple circuit structure and high conversion efficiency.

[0003] In the totem pole bridgeless circuit, a major challenge is to sample the current of the input inductor, so as to realize the control timing of the switch tube and finally realize the power factor correction and other functions. However, when sampling the current of the input inductor, one is Figure 1 As shown, the Hall sensor 200 is used for direct sampling, but the Hall sensor 200 is expensive and bulky, which results in the totem pole bridgeless circuit being expensive and bulky. Figure 2 As shown, the current of the input inductor is sampled through the sampling resistor Rp and the signal amplifier, and then the signal is transmitted to the control unit through the signal isolation circuit 210. However, this circuit is complex and costly, and requires an additional isolated auxiliary power supply to provide isolated power. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a totem pole bridgeless circuit and a power supply module, which obtain the inductor current of the input inductor through the input voltage, output current and output voltage, thereby reducing the complexity of the circuit and reducing the cost and volume of the totem pole bridgeless circuit.

[0005] In the first aspect, in order to solve the above technical problems, a technical solution adopted in an embodiment of the present invention is: to provide a totem pole bridgeless circuit, including: an input inductor, a bridge arm unit, a current sampling unit and a control unit; the first end of the input inductor is used to connect to the first end of the AC power supply; the bridge arm unit includes a first bridge arm module and a second bridge arm module connected in parallel, wherein the first bridge arm module includes a first switching tube and a second switching tube connected in series in the same direction, and the connection point between the first switching tube and the second switching tube is a first series connection point, the second bridge arm module includes a second series connection point, the connection point between the second bridge arm module and the second switching tube is a first parallel connection point, the connection point between the second bridge arm module and the first switching tube is a second parallel connection point, the first series connection point is connected to the second end of the input inductor, and the second bridge arm module includes a second series connection point. Two series connection points are connected to the second end of the AC power supply, the first parallel connection point is used to connect the first end of the load, and the second parallel connection point is used to connect the second end of the load; the current sampling unit is connected between the bridge arm unit and the load, and the current sampling unit is used to obtain the output current output by the bridge arm unit to the load; the first input end of the control unit is connected to the current sampling unit, the second input end of the control unit is used to obtain the output voltage output by the bridge arm unit to the load, the third input end of the control unit is used to obtain the AC voltage of the AC power supply, and the output end of the control unit is connected to the bridge arm unit. The control unit is used to obtain the inductor current of the input inductor based on the output voltage, the AC voltage, and the output current, and control the bridge arm unit based on the inductor current.

[0006] In some embodiments, the second bridge arm module 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 respectively connected to the first switch tube and the second end of the load, the cathode of the first diode is respectively connected to the second end of the AC power supply and the anode of the second diode, and the cathode of the second diode is respectively connected to the second switch tube and the first end of the load.

[0007] In some embodiments, the current sampling unit includes a current mutual sensing module or a sampling resistor; the first input end of the current mutual sensing module is connected to the first parallel connection point, the second input end of the current mutual sensing module is connected to the first end of the load, and the output end of the current mutual sensing module is connected to the first input end of the control unit; the first end of the sampling resistor is connected to the second parallel connection point, and the second end of the sampling resistor is respectively connected to the first input end of the control unit and the second end of the load.

[0008] In some embodiments, the current transformer module includes: a third diode, a transformer and a first resistor; the primary winding of the transformer is connected between the first parallel connection point and the first end of the load, the first end of the secondary winding of the transformer is connected to the anode of the third diode, and the cathode of the third diode is respectively connected to the first input end of the control unit and the first end of the first resistor, and the second end of the first resistor and the second end of the secondary winding of the transformer are grounded.

[0009] In some embodiments, the current transformer module further includes a second resistor; a first end of the second resistor is respectively connected to the first end of the secondary winding of the transformer and the anode of the third diode, and a second end of the second resistor is grounded.

[0010] In some embodiments, the control unit includes an ADC sampling module, an inductor current reconstruction module and a controller; the first input end of the ADC sampling module is connected to the current sampling unit, the second input end of the ADC sampling module is connected to the load, and the third input end of the ADC sampling module is connected to the AC power supply. The first output end of the ADC sampling module is respectively connected to the first input end of the inductor current reconstruction module and the first input end of the controller, the second output end of the ADC sampling module is connected to the second input end of the inductor current reconstruction module, and the third output end of the ADC sampling module is respectively connected to the third input end of the inductor current reconstruction module and the second input end of the controller. The output end of the current reconstruction module is connected to the third input end of the controller, and the output end of the controller is connected to the bridge arm unit; wherein the ADC sampling module is used to sample the output current, the AC voltage and the output voltage respectively, and output the output current, the AC voltage and the output voltage to the inductor current reconstruction module, and output the AC voltage and the output voltage to the controller; the inductor current reconstruction module is used to obtain the inductor current according to the output current, the AC voltage and the output voltage, and output the inductor current to the controller; the controller is used to control the bridge arm unit according to the AC voltage, the output voltage and the inductor current.

[0011] In some embodiments, the inductor current reconstruction module is used to obtain the inductor current i according to the following formula: L :

[0012]

[0013] Among them, I L_AVG is the output current, T 1-D is the conduction time of the freewheeling tube in the bridge arm unit, V AC is the AC voltage, VOUT is the output voltage, t is the duration after the active tube in the bridge arm unit is turned on in one switching cycle, and L1 is the inductance of the input inductor.

[0014] In some embodiments, the totem pole bridgeless circuit further includes an amplifier; and the first input terminal of the ADC sampling module is connected to both ends of the AC power supply through the amplifier.

[0015] In a second aspect, an embodiment of the present invention further provides a power supply module, which includes the totem pole bridgeless circuit as described in any one of the first aspects.

[0016] Compared with the prior art, the present invention has the following beneficial effects: Different from the prior art, the present invention provides a totem pole bridgeless circuit and power supply module, comprising an input inductor, a bridge arm unit, a current sampling unit, and a control unit; the first end of the input inductor is used to connect to the first end of an AC power supply; the current sampling unit is connected between the bridge arm unit and a load, and the current sampling unit is used to obtain an output current output by the bridge arm unit to the load; the first input end of the control unit is connected to the current sampling unit, the second input end is used to obtain the output voltage output by the bridge arm unit to the load, the third input end is used to obtain the AC voltage of the AC power supply, and the output end is connected to the bridge arm unit; the control unit is used to output the voltage, AC voltage, and output current to obtain the inductor current of the input inductor, and control the bridge arm unit based on the inductor current. The control unit obtains the inductor current of the input inductor through the input voltage, output current, and output voltage, without directly sampling the inductor current of the input inductor, thereby reducing the complexity of the circuit and reducing the cost and volume of the totem pole bridgeless circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily described by pictures in the corresponding drawings. These exemplified descriptions do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise stated, the figures in the drawings do not constitute a scale limitation.

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

[0019] Figure 2 It is a structural block diagram of another totem pole bridgeless circuit provided in the prior art;

[0020] Figure 3 This is a structural block diagram of a totem pole bridgeless circuit provided by an embodiment of the present invention;

[0021] Figure 4 1 is a schematic diagram of a circuit structure of a totem pole bridgeless circuit provided by an embodiment of the present invention;

[0022] Figure 5 1 is a schematic diagram of a circuit structure of another totem pole bridgeless circuit provided by an embodiment of the present invention;

[0023] Figure 6 1 is a schematic diagram of the working state of the first totem pole bridgeless circuit provided by an embodiment of the present invention;

[0024] Figure 7 1 is a schematic diagram of the working state of the second totem pole bridgeless circuit provided by an embodiment of the present invention;

[0025] Figure 8 1 is a schematic diagram of the working state of the third totem pole bridgeless circuit provided by an embodiment of the present invention;

[0026] Figure 9 1 is a schematic diagram of the working state of the fourth totem pole bridgeless circuit provided by an embodiment of the present invention;

[0027] Figure 10 This is a waveform diagram of an actual inductor current, output current, ADC sampling module sampling signal, and reconstructed inductor current provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0029] For ease of understanding of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those generally understood by those skilled in the art in the field of the present application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0030] It should be noted that, unless they conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of this application. Furthermore, although the functional modules are divided in the device schematic, in some cases, the module division may be different from that in the device. Furthermore, the terms "first," "second," and the like used herein do not limit the order of data or execution; they are merely used to distinguish between identical or similar items with substantially the same functions and effects.

[0031] In the first aspect, an embodiment of the present invention provides a totem pole bridgeless circuit, see Figure 3 and Figure 4 The totem pole bridgeless circuit includes: an input inductor L1, a bridge arm unit 10, a current sampling unit 20 and a control unit 30.

[0032] The first end of the input inductor L1 is used to connect to the first end of the AC power source AC1. The bridge arm unit 10 includes a first bridge arm module 11 and a second bridge arm module 12 connected in parallel, wherein the first bridge arm module 11 includes a first switch transistor Q1 and a second switch transistor Q2 connected in series in the same direction, and the connection point between the first switch transistor Q1 and the second switch transistor Q2 is a first series connection point P1. The second bridge arm module 12 includes a second series connection point P2. The connection point between the second bridge arm module 12 and the second switch transistor Q2 is a first parallel connection point P3. The connection point between the second bridge arm module 12 and the first switch transistor Q1 is a second parallel connection point P4. The first series connection point P1 is connected to the second end of the input inductor L1, the second series connection point P2 is connected to the second end of the AC power source AC1, the first parallel connection point P3 is used to connect to the first end of the load 300, and the second parallel connection point P4 is used to connect to the second end of the load 300. The current sampling unit 20 is connected between the bridge arm unit 10 and the load 300 and is used to obtain the output current of the bridge arm unit 10 to the load 300. The first input terminal of the control unit 30 is connected to the current sampling unit 20, the second input terminal of the control unit 30 is used to obtain the output voltage of the bridge arm unit 10 to the load 300, and the third input terminal of the control unit 30 is used to obtain the AC voltage of the AC power supply AC1. The output terminal of the control unit 30 is connected to the bridge arm unit 10. The control unit 30 is used to obtain the inductor current of the input inductor L1 based on the output voltage, the AC voltage, and the output current, and control the bridge arm unit 10 based on the inductor current.

[0033] The control unit 30 may obtain the AC voltage and output voltage of the AC power source AC1 by any suitable voltage sampling unit in the prior art, which is not limited here.

[0034] When the totem pole bridgeless circuit operates with the active transistor in the bridge arm unit 10 turned on, that is, when the input inductor L1 is in the energy storage state, the load 300 unit is not powered, and the current sampling unit 20 cannot collect the output current. When the totem pole bridgeless circuit operates with the freewheeling transistor in the bridge arm unit 10 turned on, that is, when the input inductor L1 is in the discharge state, the load 300 unit is powered, and the current sampling unit 20 can collect the output current. It should be noted that regardless of whether the alternating current is in the positive half cycle or the negative half cycle, the working state of the current sampling unit 20 is the same, that is, when the input inductor L1 is in the energy storage state, the current sampling unit 20 cannot collect the output current, and when the input inductor L1 is in the discharge state, the current sampling unit 20 can collect the output current.

[0035] Since the output current is the current collected by the current sampling unit 20 when the freewheeling tube in the bridge arm unit 10 is turned on, that is, when the input inductor L1 is in a discharge state, then the current is also the average current during the period when the freewheeling tube in the bridge arm unit 10 is turned on. In this way, the subsequent control unit 30 can perform signal processing based on the sampled input voltage (that is, AC voltage), output current and output voltage to obtain the inductor current of the input inductor L1, and control the bridge arm unit 10 based on the inductor current. Regarding the specific method of the control unit 30 controlling the bridge arm unit 10 based on the inductor current, please refer to the existing technology and will not be repeated here. In this embodiment, the control unit 30 reconstructs the inductor current of the input inductor L1 based on the input voltage, output current and output voltage. Compared with the method of directly using a Hall sensor or a sampling resistor to sample and obtain the inductor current in the prior art, this embodiment can reduce the complexity of the hardware circuit and reduce the cost and volume of the totem pole bridgeless circuit.

[0036] In some embodiments, the load 300 further includes a load capacitor C1 and a load resistor RL; wherein a first end of the load resistor C1 is connected to the bridge arm unit 10, a second end of the load resistor RL is connected to the current sampling unit 20, and the load capacitor C1 and the load resistor RL are connected in parallel.

[0037] In some of these examples, see Figure 4 The second bridge arm module 12 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 a second series connection point P2, the anode of the first diode D1 is respectively connected to the first switch tube Q1 and the second end of the load 300, the cathode of the first diode D1 is respectively connected to the second end of the AC power supply AC1 and the anode of the second diode D2, and the cathode D2 of the second diode is respectively connected to the second switch tube Q2 and the first end of the load 300.

[0038] For details, please refer to Figure 4In some embodiments, the first bridge arm module 11 includes a first switch tube Q1 and a second switch tube Q2, and the second bridge arm module 12 includes a first diode D1 and a second diode D2; the first end of the first switch tube Q1 is respectively connected to the second end of the input inductor L1 and the first end of the second switch tube Q2, the second end of the first switch tube Q1 is respectively connected to the anode of the first diode D1 and the second end of the load 300, the second end of the second switch tube Q2 is respectively connected to the cathode of the second diode D2 and the first end of the load 300, the cathode of the first diode D1 is respectively connected to the second end of the AC power supply AC1 and the anode of the second diode D2, and the third end of the first switch tube Q1 and the third end of the second switch tube Q2 are connected to the control unit 30. The current sampling unit 20 is connected between the second switch tube Q2 and the first end of the load 300, or, as shown in FIG. Figure 5 As shown, the current sampling unit 20 is connected between the first switch tube Q1 and the second end of the load 300 .

[0039] In this totem pole bridgeless circuit, the control unit 30 controls the on / off switching of the first switch Q1 and the second switch Q2, as well as the duty cycle of the drive signal, via the drive signals output from the output terminals GATE_Q1 and GATE_Q2. For example, the control unit 30 controls the on / off switching of the active transistor and the off-load transistor in the first switch Q1 and the second switch Q2 according to the duty cycle. Alternatively, the control unit 30 controls the off-load switching of the first switch Q1 and the second switch Q2 to achieve protection when an overvoltage is detected. Alternatively, the control unit 30 adjusts the duty cycle of the drive signal according to the inductor current to adjust the output power of the circuit. Software design can be performed based on actual needs. The drive signal can be a pulse width modulation (PWM) signal.

[0040] In this totem pole bridgeless circuit, when the AC power source AC1 outputs AC power in the positive half cycle, the first switch tube Q1 is an active tube and the second switch tube Q2 is a freewheeling tube, working in a complementary on state. Figure 6 When the first switch Q1 is turned on and the second switch Q2 is turned off, current flows through the positive terminal of the AC power source AC1 to the input inductor L1, the first switch Q1, the first diode D1, and then flows back to the negative terminal of the AC power source AC1. At this time, the input inductor L1 operates in an energy storage state. The AC power source AC1 stores energy in the input inductor L1. Current does not flow through the current sampling unit 20, and there is no current signal. At the same time, the load capacitor C1 discharges the load resistor RL. Next, please refer to Figure 7When the first switch Q1 is turned off and the second switch Q2 is turned on, current flows through the positive terminal of the AC power source AC1 to the input inductor L1, the second switch Q2, the current sampling unit 20, the load 300, the first diode D1, and then flows back to the negative terminal of the AC power source AC1. At this time, the inductor L1 is operating in an energy release state, releasing energy to the load resistor RL, and the load capacitor C1 is operating in a charging state. The current flows through the current sampling unit 20, and the control unit obtains the output current.

[0041] When the AC power source AC1 outputs AC power in the negative half cycle, the second switch tube Q2 is an active tube and the first switch tube Q1 is a freewheeling tube, working in a complementary on state. Figure 8 When the second switch Q2 is turned on and the first switch Q1 is turned off, the current flows through the positive terminal of the AC power source AC1 to the second diode D2, the second switch Q2, the input inductor L1, and then back to the negative terminal of the AC power source AC1. The input inductor L1 operates in an energy storage state. The AC power source AC1 stores energy in the input inductor L1. The current does not pass through the current sampling unit 20. At the same time, the load capacitor C1 discharges the load resistor RL. Next, please refer to Figure 9 When the second switch tube Q2 is turned off and the first switch tube Q1 is turned on, the current flows through the positive terminal of the AC power source AC1 to the second diode D2, the current sampling unit 20, the load 300, the first switch tube Q1, the input inductor L1, and then flows back to the negative terminal of the AC power source AC1. The input inductor L1 operates in an energy release state, releasing energy to the load resistor RL, and the load capacitor C1 operates in a charging state. The control unit 30 obtains the output current through the current sampling unit 20.

[0042] It should be noted that Figure 4 The second bridge arm module 12 uses two diodes connected in series as an example of a bridge arm. The two diodes can also be replaced by switching tubes to operate in synchronous rectifier mode. The first switching tube Q1 and the second switching tube Q2 are N-channel metal oxide semiconductor field effect transistors. In actual application scenarios, the first switching tube Q1 and the second switching tube Q2 can also be other types of triodes such as electronic triodes (Triode), bipolar junction transistors (Bipolar Junction Transistor, BJT), J-type field effect transistors (Junction gate Field Effect Transistor, JFET), V-type field effect transistors (Vertical Metal Oxide Semiconductor, VMOS), etc., and the specific selection can be based on actual needs.

[0043] In some embodiments, the current sampling unit 20 includes a current mutual inductance module or a sampling resistor Rs; see Figure 4The first input terminal of the current mutual sensing module is connected to the first parallel connection point P3, the second input terminal of the current mutual sensing module is connected to the first terminal of the load 300, and the output terminal of the current mutual sensing module is connected to the first input terminal of the control unit 30; please refer to Figure 5 A first end of the sampling resistor Rs is connected to the second parallel connection point P4 , and a second end of the sampling resistor Rs is connected to the first input end of the control unit 30 and the second end of the load 300 , respectively.

[0044] In some of these examples, see Figure 4 The current transformer module includes: a third diode D3, a transformer CT1, and a first resistor R1. The primary winding of the transformer CT1 is connected between the first parallel connection point P3 and the first end of the load 300. The first end of the secondary winding of the transformer CT1 is connected to the anode of the third diode D3. The cathode of the third diode D3 is connected to the first input terminal of the control unit 30 and the first end of the first resistor R1, respectively. The second end of the first resistor R1 and the second end of the secondary winding of the transformer CT1 are grounded. In this current transformer module, when the output current flows through the primary winding of the transformer CT1, the secondary winding of the transformer CT1 will generate a current. The current direction of the current is from the anode of the third diode D3 to the cathode of the third diode D3. In this way, the first end of the first resistor R1 generates a divided voltage. The output current can be obtained by sampling the divided voltage signal and calculating it. In this embodiment, using the transformer CT1 to sample the current can reduce the cost and volume of the sampling circuit.

[0045] In some of these examples, please see Figure 4 The current mutual sensing module further includes a second resistor R2; a first end of the second resistor R2 is respectively connected to the first end of the secondary winding of the transformer CT1 and the anode of the third diode D3, and a second end of the second resistor R2 is grounded.

[0046] In some of these examples, see Figure 4 or Figure 5The control unit 30 includes an ADC sampling module 31, an inductor current reconstruction module 32, and a controller 33. A first input terminal of the ADC sampling module 31 is connected to the current sampling unit 20, a second input terminal of the ADC sampling module 31 is connected to the load 300, and a third input terminal of the ADC sampling module 31 is connected to the AC power supply AC1. A first output terminal of the ADC sampling module 31 is respectively connected to the first input terminal of the inductor current reconstruction module 32 and the first input terminal of the controller 33. A second output terminal of the ADC sampling module 31 is connected to the second input terminal of the inductor current reconstruction module 32. A third output terminal of the ADC sampling module 31 is respectively connected to the third input terminal of the inductor current reconstruction module 32 and the second input terminal of the controller 33. An output terminal of the inductor current reconstruction module 32 is connected to the third input terminal of the controller 33. An output terminal of the controller 33 is connected to the bridge arm unit 10.

[0047] The ADC sampling module 31 is configured to sample the output current, AC voltage, and output voltage, respectively, and output the output current, AC voltage, and output voltage to the inductor current reconstruction module 32, and output the AC voltage and output voltage to the controller 33. The inductor current reconstruction module 32 is configured to obtain the inductor current based on the output current, AC voltage, and output voltage, and output the inductor current to the controller 33. The controller 33 is configured to control the bridge arm unit 10 based on the AC voltage, output voltage, and inductor current.

[0048] In this embodiment, the ADC sampling module 31 converts the sampled AC voltage sampling signal, the transformer current sampling signal, and the output voltage sampling signal into digital signals and supplies them to the inductor current reconstruction module 32 and the controller 33. In this way, the inductor current reconstruction module 32 can obtain the output current, AC voltage, and output voltage, and the controller 33 can obtain the AC voltage and output voltage.

[0049] The inductor current reconstruction module 32 and the controller 33 may both adopt a micro control unit 30 , the specific model of which can be freely set and is not limited here.

[0050] Specifically, in order to reduce the cost of ADC sampling, a Σ-Δ (Sigma-Delta) ADC can be selected to collect current signals. This ADC sampling module 31 cannot collect instantaneous current signals, but can only collect average current signals over a period of time. Figure 4 In the example, the current signal collected by transformer CT1 is the average current signal ICT1_AVG, which is equivalent to the average current signal IL_AVG of the input inductor L1 during the freewheeling diode's on-state. The operating mode of the totem pole bridgeless circuit is equivalent to the boost circuit operating mode. Based on the boost circuit operating mode, the relationship between the input voltage, output voltage, and the rate of change of the inductor current can be calculated.

[0051] The relationship between the rate of change of the current of the input inductor L1 when the active tube is turned on is as follows:

[0052]

[0053] The relationship between the rate of change of the current of the input inductor L1 when the freewheeling tube is turned on is as follows:

[0054]

[0055] Among them, V AC is the input AC voltage, V OUT is the output voltage, L1 is the inductance of inductor L1. AC The value of V OUT The value of is small, so the rate of change of the current of the input inductor L1 when the freewheeling tube is turned on is negative.

[0056] See also Figure 10 , where T D is the conduction time of the active transistor in the bridge arm unit 10, T 1-D is the conduction time of the freewheeling tube in the bridge arm unit 10, and one switching cycle of the bridge arm unit 10 is T D +T 1-D The transformer CT1 can only collect T 1-D The current signal during the period can be obtained by sampling the Σ-Δ ADC sampling module. 1-D The average current signal I of the input inductor L1 during the period L_AVG , I L_AVG is also the output current. Then, when the freewheeling tube is turned off and the active tube is turned on, the instantaneous current I of the input inductor L1 is L for:

[0057]

[0058] Then, during the subsequent active transistor on-state period, the instantaneous current of inductor L1 can be reconstructed as follows:

[0059]

[0060] Wherein, t is the duration after the active tube is turned on in one switching cycle.

[0061] As can be seen, the instantaneous current of the input inductor L1 during the subsequent charging cycle can be reconstructed through the above method. By using this instantaneous current as the inductor current of the input inductor, it can be used to implement loop control of the power factor correction circuit or various protection functions such as overcurrent protection. In summary, in this embodiment, the control unit obtains the inductor current of the input inductor through the input voltage, output current, and output voltage, eliminating the need to directly sample the inductor current of the input inductor, thereby reducing circuit complexity and reducing the cost and size of the totem pole bridgeless circuit.

[0062] In some of these examples, see Figure 4 The totem pole bridgeless circuit further includes an amplifier U1. The first input terminal of the ADC sampling module 31 is connected to both ends of the AC power supply AC1 through the amplifier U1. By providing the amplifier U1, the AC power supply AC1 can be sampled to obtain an AC voltage.

[0063] In a second aspect, an embodiment of the present invention provides a power supply module, comprising: a totem pole bridgeless circuit as described in any one of the first aspects. In this embodiment, the totem pole bridgeless circuit has the same structure and function as the totem pole bridgeless circuit described in any one of the first aspects, and thus is not further described herein.

[0064] It should be noted that the device embodiments described above are merely illustrative, wherein 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 may be selected based on actual needs to achieve the objectives of this embodiment.

[0065] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the relevant technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for executing the methods described in each embodiment or certain parts of the embodiment using at least one computer device (which can be a personal computer, a server, or a network device, etc.).

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions 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: an input inductor, wherein a first end of the input inductor is used to connect to a first end of an AC power source; A bridge arm unit, comprising a first bridge arm module and a second bridge arm module connected in parallel, wherein the first bridge arm module comprises a first switching tube and a second switching tube connected in series in the same direction, and the connection point between the first switching tube and the second switching tube is a first series connection point, the second bridge arm module comprises a second series connection point, the connection point between the second bridge arm module and the second switching tube is a first parallel connection point, and the connection point between the second bridge arm module and the first switching tube is a second parallel connection point, the first series connection point is connected to the second end of the input inductor, the second series connection point is connected to the second end of the AC power supply, the first parallel connection point is used to connect to the first end of a load, and the second parallel connection point is used to connect to the second end of the load; a current sampling unit, connected between the bridge arm unit and the load, and configured to obtain an output current outputted from the bridge arm unit to the load; a control unit, wherein a first input end of the control unit is connected to the current sampling unit, a second input end of the control unit is used to obtain an output voltage output by the bridge arm unit to the load, a third input end of the control unit is used to obtain the AC voltage of the AC power supply, an output end of the control unit is connected to the bridge arm unit, the control unit is used to obtain the inductor current of the input inductor based on the output voltage, the AC voltage, and the output current, and control the bridge arm unit based on the inductor current, the control unit includes an ADC sampling module, an inductor current reconstruction module, and a controller, the ADC sampling module is used to sample the output current, the AC voltage, and the output voltage respectively, and output the output current, the AC voltage, and the output voltage to the inductor current reconstruction module, and output the AC voltage and the output voltage to the controller; the inductor current reconstruction module is used to obtain the inductor current based on the output current, the AC voltage, and the output voltage, and output the inductor current to the controller; the controller is used to control the bridge arm unit based on the AC voltage, the output voltage, and the inductor current; The inductor current reconstruction module is used to obtain the inductor current according to the following formula : ； in, is the output current, is the conduction time of the freewheeling tube in the bridge arm unit, is the AC voltage, is the output voltage, is the duration after the active transistor in the bridge arm unit is turned on in one switching cycle, is the inductance of the input inductor.

2. The totem pole bridgeless circuit according to claim 1, wherein: The second bridge arm module 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 respectively connected to the first switching tube and the second end of the load, the cathode of the first diode is respectively connected to the second end of the AC power supply and the anode of the second diode, and the cathode of the second diode is respectively connected to the second switching tube and the first end of the load.

3. The totem pole bridgeless circuit according to claim 1 or 2, characterized in that: The current sampling unit includes a current mutual induction module or a sampling resistor; The first input end of the current mutual sensing module is connected to the first parallel connection point, the second input end of the current mutual sensing module is connected to the first end of the load, and the output end of the current mutual sensing module is connected to the first input end of the control unit; The first end of the sampling resistor is connected to the second parallel connection point, and the second end of the sampling resistor is respectively connected to the first input end of the control unit and the second end of the load.

4. The totem pole bridgeless circuit according to claim 3, characterized in that: The current mutual induction module includes: a third diode, a mutual inductor and a first resistor; The primary winding of the mutual inductor is connected between the first parallel connection point and the first end of the load, the first end of the secondary winding of the mutual inductor is connected to the anode of the third diode, the cathode of the third diode is respectively connected to the first input end of the control unit and the first end of the first resistor, and the second end of the first resistor and the second end of the secondary winding of the mutual inductor are grounded.

5. The totem pole bridgeless circuit according to claim 4, characterized in that: The current mutual sensing module further includes a second resistor; A first end of the second resistor is respectively connected to a first end of the secondary winding of the transformer and an anode of the third diode, and a second end of the second resistor is grounded.

6. The totem pole bridgeless circuit according to claim 1 or 2, characterized in that: The first input end of the ADC sampling module is connected to the current sampling unit, the second input end of the ADC sampling module is connected to the load, and the third input end of the ADC sampling module is connected to the AC power supply. The first output end of the ADC sampling module is respectively connected to the first input end of the inductor current reconstruction module and the first input end of the controller. The second output end of the ADC sampling module is connected to the second input end of the inductor current reconstruction module. The third output end of the ADC sampling module is respectively connected to the third input end of the inductor current reconstruction module and the second input end of the controller. The output end of the inductor current reconstruction module is connected to the third input end of the controller, and the output end of the controller is connected to the bridge arm unit.

7. The totem pole bridgeless circuit according to claim 6, wherein: The totem pole bridgeless circuit further includes an amplifier; The first input terminal of the ADC sampling module is connected to two ends of the AC power supply through the amplifier.

8. A power supply module, characterized in that: include: The totem pole bridgeless circuit according to any one of claims 1 to 7.

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