CN114257078A - Totem-pole PFC inductive current synthesis circuit and equipment - Google Patents

Abstract

The invention discloses a totem pole PFC inductor current synthesis circuit and equipment, comprising: a power circuit module and a control circuit module; the power circuit includes: an alternating current power supply, an inductor, an input voltage signal unit and a totem pole PFC circuit unit; the totem pole PFC circuit The unit includes: a first power switch, a second power switch, a third power switch, a fourth power switch, a first shunt resistor and a second shunt resistor; the control circuit module includes: an input voltage detection unit, a first output voltage detection unit, The second output voltage detection unit and the inductor current synthesis unit. In the present invention, the shunt resistor is connected in series between the power switch source and the ground and the voltage drop of the shunt resistor is measured to complete the inductance current synthesis, which has the advantages of small size and low cost.

Description

Totem pole PFC inductor current synthesis circuit and equipment

technical field

The invention relates to the technical field of power electronics, in particular to a totem pole PFC inductor current synthesis circuit and device.

Background technique

For power electronic converters powered by single-phase AC voltage, active power factor correction (PFC) technology or single-phase active power filter (APF) technology is required to suppress grid-side harmonic currents and improve grid-side power. factor, meet IEC61000-3-2 and IEC6100-3-12 harmonic current suppression label. The power circuit and control circuit in the totem pole PFC, the power circuit includes two bridge arms, in general, one is a high-frequency switching GaN FET or IGBT bridge arm, and the other is a power frequency switching SiC FET or diode bridge arm. The circuits include analog control circuits or digital control circuits. Totem-pole PFC is an active power factor correction circuit. Like other PFC circuits, the output capacitor voltage can be controlled by PI controller, transconductance single-zero unipolar controller, etc. The inductor current can be controlled by following control, single-cycle control, etc. control and hysteresis control, etc. No matter which control method is adopted, the instantaneous value of the inductor current must be detected and compared with the reference current as the inner loop current control error. The inductive current of the totem pole PFC generally uses a Hall current sensor and a linear isolation amplifier, which requires an auxiliary power supply, which has the problems of high cost and large volume.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the above-mentioned prior art, the present invention proposes a totem-pole PFC inductor-current synthesizing circuit and equipment, so as to solve the problems of high cost and large volume in the prior art.

In order to solve the above-mentioned technical problems, the present invention is achieved through the following technical solutions:

According to a first aspect of the present invention, a totem pole PFC inductor current synthesis circuit is provided, which includes: a power circuit module and a control circuit module; wherein,

The power circuit module includes: an AC power supply, an inductor, an input voltage signal unit and a totem pole PFC circuit unit;

The totem pole PFC circuit unit includes: a first power switch, a second power switch, a third power switch, a fourth power switch, a first shunt resistor and a second shunt resistor;

The live wire of the AC power source is connected to the input end of the input voltage signal unit, and the live wire of the AC power source is also connected to the first end of the inductor;

The source of the first power switch is connected to the drain of the second power switch, and the node between the source of the first power switch and the drain of the second power switch is connected to the second node of the inductor. end;

The source of the third power switch is connected to the drain of the fourth power switch, and the node between the source of the third power switch and the drain of the fourth power switch is connected to zero of the AC power supply Wire;

The drain of the first power switch is connected to the drain of the third power switch;

The source of the second power switch is connected to one end of the first shunt resistor, and the other end of the first shunt resistor is grounded;

The source of the fourth power switch is connected to one end of the second shunt resistor, and the other end of the second shunt resistor is grounded;

The control circuit module includes: an input voltage detection unit, a first output voltage detection unit, a second output voltage detection unit, and an inductor current synthesis unit;

The output terminal of the input voltage signal unit is connected to the input terminal of the input voltage detection unit;

An input end of the first output voltage detection unit is connected to both ends of the first shunt resistor;

An input end of the second output voltage detection unit is connected to both ends of the second shunt resistor;

The output end of the input voltage detection unit, the output end of the first output voltage detection unit, and the output end of the second output voltage detection unit are respectively connected to the input end of the inductor current synthesis unit, and the inductor current synthesis unit The output of the cell is configured to output the combined inductor current.

Preferably, the inductor current synthesis unit includes: a polarity determination unit, U6, a rising current calculation unit, a multiplier, a first adder and a second adder; wherein,

The output end of the input voltage detection unit is connected to the input end of the polarity judgment unit;

The output end of the polarity judgment unit is connected to the first input end of the multiplier;

The output end of the first output voltage detection unit is connected to the second input end of the multiplier;

The output terminal of the multiplier is connected to the first input terminal of the rising current calculation unit;

The node between the input voltage detection unit and the polarity determination unit is also connected to the input end of the slope calculation unit;

The output end of the slope calculation unit is connected to the second input end of the rising current calculation unit;

The output end of the rising current calculation unit is connected to the first input end of the first adder;

The node between the multiplier and the rising current calculation unit is further connected to the second input of the first adder;

The output end of the first adder is connected to the first input end of the second adder;

The output end of the second output voltage detection unit is connected to the second input end of the second adder;

The second summer is configured to output the combined inductor current.

Preferably, the power circuit module further comprises: a first capacitor;

The totem pole PFC circuit unit further includes: a second capacitor, a first resistance unit, and a second resistance unit; wherein,

The first end of the first capacitor is connected to the first end of the inductor, and the node between the source of the third power switch and the drain of the fourth power switch is also connected to the first end of the first capacitor. two ends;

The node between the drain of the first power switch and the drain of the third power switch is connected to the first end of the first resistance unit, and the second end of the first resistance unit is connected to the second The first end of the resistance unit and the second end of the second resistance unit are grounded.

Preferably, the totem pole PFC circuit unit further comprises: a first filtering unit and a second filtering unit; wherein,

The first end of the first shunt resistor is connected to the input end of the first output voltage detection unit through the first filter unit;

The first end of the second shunt resistor is connected to the input end of the second output voltage detection unit through the second filter unit.

Preferably, the first filter unit includes: a first filter resistor and a first filter capacitor; the second filter unit includes: a second filter resistor and a second filter capacitor; wherein,

The first end of the first filter resistor is connected to the first end of the first shunt resistor, the second end of the first filter resistor is connected to the first end of the first filter capacitor, and the first filter resistor The node between the first filter capacitor and the first filter capacitor is also connected to the input end of the first output voltage detection unit, and the second end of the first filter capacitor is grounded;

The first end of the second filter resistor is connected to the first end of the second shunt resistor, the second end of the second filter resistor is connected to the first end of the second filter capacitor, and the second filter resistor The node between the second filter capacitor and the second filter capacitor is also connected to the input end of the second output voltage detection unit, and the second end of the second filter capacitor is grounded.

Preferably, the first resistance unit includes: a plurality of resistors connected in series; and/or,

The second resistance unit includes: a plurality of resistors connected in series in sequence. The withstand voltage of a single resistor is limited, so using multiple resistors in series can increase the withstand voltage and prolong the life of the circuit.

Preferably, the first power switch and the second power switch are GaN field effect transistors.

Preferably, the third power meter switch and the fourth power switch are silicon carbide field effect transistors.

Preferably, the input voltage signal unit includes: a first input resistance, a second input resistance, a third input resistance, a fourth input resistance, a first diode and a second diode; wherein,

The first end of the first input resistor is connected to the neutral line of the AC power supply, the second end of the first input resistor is connected to the first end of the second input resistor, and the second end of the second input resistor is connected to the first end of the second input resistor. terminal grounding;

The node between the first input resistor and the second input resistor is also connected to the first end of the first diode;

The first end of the third input resistor is connected to the live wire of the AC power supply, the second end of the third input resistor is connected to the first end of the fourth input resistor, and the other end of the fourth input resistor is grounded ;

The node between the third input resistor and the fourth input resistor is further connected to the second end of the first diode;

The node between the second input resistor and the first diode is also connected to the first end of the second diode;

The node between the fourth input resistor and the first diode is also connected to the second end of the second diode;

The node connecting the second input resistor and the second diode is also connected to the first input terminal of the input voltage detection unit;

The node where the third input resistor is connected to the first diode is also connected to the second input terminal of the input voltage detection unit.

According to a second aspect of the present invention, there is provided a totem-pole PFC inductor-current synthesis device, which includes: the totem-pole PFC inductor-current synthesis circuit described above.

Compared with the prior art, the present invention has the following advantages:

In the totem pole PFC inductor current synthesis circuit and device provided by the present invention, the first output voltage detection unit and the second output voltage detection unit measure the voltage drop of the two shunt resistors of the totem pole PFC circuit to complete the synthesis or reconstruction of the inductor current , has the advantages of small size and low cost.

Description of drawings

Embodiments of the present invention are further described below in conjunction with the accompanying drawings:

FIG. 1 is a schematic diagram of a totem-pole PC inductor current synthesis circuit according to an embodiment of the present invention.

Description of reference numbers:

1- Power circuit module,

2- control circuit module;

U1 - input voltage detection unit,

U2 - the first output voltage detection unit,

U3 - the second output voltage detection unit,

U4 - limit judgment unit,

U5 - Multiplier,

U6 - slope calculation unit,

U7 - rising current calculation unit,

U8 - first adder,

U9 - Second adder.

Detailed ways

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and provides detailed implementation modes and specific operation processes, but the protection scope of the present invention is not limited to the following implementations example.

The terms "first", "second", "third", "fourth", etc. (if present) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to Describe a particular order or sequence. It is to be understood that the data so used may be interchanged under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

In one embodiment, a totem pole PFC inductor current synthesis circuit is provided, which includes: a power circuit module 1 and a control circuit module 2 , please refer to FIG. 1 . The power circuit module 1 includes: an AC power source _ui , an inductance L1, an input voltage signal unit and a totem-pole PFC circuit unit; the totem-pole PFC circuit unit includes: a first power switch S1, a second power switch S2, and a third power switch S3, the fourth power switch S4, the first shunt resistor R8 and the second shunt resistor R10. The live wire L of the AC power source _ui is connected to the input end of the input voltage signal unit, and the live wire L of the AC power source _ui is also connected to the first end of the inductor L1. The source of the first power switch S1 is connected to the drain of the second power switch S2, and the node between the source of the first power switch S1 and the drain of the second power switch S2 is connected to the second end of the inductor L1. The source of the third power switch S3 is connected to the drain of the fourth power switch S4, and the node between the source of the third power switch S3 and the drain of the fourth power switch S4 is connected to the neutral line N of the AC power source _ui . The drain of the first power switch S1 is connected to the drain of the third power switch S3; the source of the second power switch S2 is connected to the first end of the first shunt resistor R8, and the second end of the first shunt resistor R8 is grounded. The source of the fourth power switch S4 is connected to the first end of the second shunt resistor R10, and the second end of the second shunt resistor R10 is grounded. The control circuit module includes: an input voltage detection unit U1, a first output voltage detection unit U2, a second output voltage detection unit U3 and an inductor current synthesis unit; the input voltage detection unit U1 is connected to the output end of the input voltage signal unit to receive the input voltage Signal u _i1 ; the first output voltage detection unit U2 is connected to both ends of the first shunt resistor R8 to receive the voltage drop signal U _R1 of the first shunt resistor R8; the second output voltage detection unit U3 is connected to the two ends of the second shunt resistor R10. terminal to receive the voltage drop signal U _R2 of the second shunt resistor R10 . The output terminals of the input voltage detection unit U1, the first output voltage detection unit U2, and the second output voltage detection unit U3 are respectively connected to the input terminals of the inductor current combining unit, and the output terminal of the inductor current combining unit outputs the combined inductor current.

In one embodiment, the inductor current synthesis unit includes: a polarity determination unit U4, a slope calculation unit U6, a rising current calculation unit U7, a multiplier U5, a first adder U8 and a second adder U9, please refer to FIG. 1 . Wherein, the output end of the input voltage detection unit U1 is connected with the input end of the polarity judgment unit U4, the input voltage detection unit U1 outputs the voltage signal u _i2 ; the output end of the polarity judgment unit U4 is connected with an input end of the multiplier U5, The polarity determination unit U4 outputs a power frequency square wave; the output end of the first output voltage detection unit U2 is connected to the other input end of the multiplier U5. The output end of the multiplier U5 is connected with an input end of the rising current calculation unit U7; the node between the input voltage detection unit U1 and the polarity judgment unit U4 is also connected with the input end of the slope calculation unit U6, and the slope calculation unit U6 is used for Calculate u _i2 /L ₁ ; the output terminal of the slope calculation unit U6 is connected to the other input terminal of the rising current calculation unit U7. The output terminal of the rising current calculation unit U7 is connected to an input terminal of the first adder U8. The node between the multiplier U5 and the rising current calculation unit U7 is also connected to the other input terminal of the first adder U8. The output end of the first adder U8 is connected to an input end of the second adder U9; the output end of the second output voltage detection unit U3 is connected to the other input end of the second adder U9. The output of the second adder is the synthesized inductor current i _L1 '.

In the prior art, the input current, i.e., the inductor current detection circuit, has to face the problem of isolation detection, linearity and response time. For totem-pole PFC with high switching frequency, the isolation problem, linearity and response time are critical issues. important factor, and the cost is also very high. On the other hand, the inductor current synthesis unit of the above-mentioned embodiment of the present invention does not need to consider the isolation problem, and has the advantages of high linearity, short response time and low cost.

In one embodiment, the power circuit module further includes: a first capacitor C1; the totem pole PFC circuit unit further includes: a second capacitor C2, a first resistor unit, and a second resistor unit, please refer to FIG. 1 . The first end of the first capacitor C1 is connected to the first end of the inductor L1, and the node between the source of the third power switch S3 and the drain of the fourth power switch S4 is also connected to the second end of the first capacitor C1. The node between the drain of the first power switch S1 and the drain of the third power switch S3 is connected to the first end of the first resistance unit, the second end of the first resistance unit is connected to the first end of the second resistance unit, and the second end of the first resistance unit is connected to the first end of the second resistance unit. The second ends of the two resistance units are grounded.

In one embodiment, the totem pole PFC circuit unit further includes: a first filter unit and a second filter unit; wherein the first end of the first shunt resistor is connected to the input end of the first output voltage detection unit through the first filter unit; The first end of the two-shunt resistor is connected to the input end of the second output voltage detection unit through the second filter unit.

In one embodiment, the first filter unit includes: a first filter resistor R9 and a first filter capacitor C3; the second filter unit includes: a second filter resistor R11 and a second filter capacitor C4, please refer to FIG. 1 . The first end of the first filter resistor R9 is connected to the first end of the first shunt resistor R8, the second end of the first filter resistor R9 is connected to the first end of the first filter capacitor C3, and the first filter resistor R9 is connected to the first end of the first filter capacitor C3. The node between the filter capacitors C3 is also connected to the input end of the first output voltage detection unit U2, and the second end of the first filter capacitor C3 is grounded. The first end of the second filter resistor R11 is connected to the first end of the second shunt resistor R10, the second end of the second filter resistor R11 is connected to the first end of the second filter capacitor C4, the second filter resistor R11 and the second filter capacitor The node between C4 is also connected to the input end of the second output voltage detection unit U3, and the second end of the second filter capacitor C4 is grounded. The first output voltage detection unit outputs U _R81 , and the second output voltage detection unit outputs a voltage U _R101 . The power circuit of this embodiment can realize the conversion of single-phase AC voltage to DC voltage, and convert the AC voltage to DC voltage, which can be used for the load of the downstream DC power supply, and at the same time, the unit power factor of the grid side can be obtained, and there is no harmonic to the grid. Current pollution. In addition, the power circuit has the advantage of the highest conversion efficiency compared with other similar single-phase AC-DC converters.

In one embodiment, the first resistance unit includes: a plurality of resistors connected in series in sequence. For example, two resistors R1 and R2 in series can be included, please refer to Figure 1. In different embodiments, two or more resistors connected in series may also be included. Of course, only one resistor may be included.

In one embodiment, the second resistor unit may only include one resistor R3 , please refer to FIG. 1 . In different embodiments, two or more resistors connected in series may also be included.

In one embodiment, the first power switch S1 and the second power switch S2 are gallium nitride field effect transistors (GaNFETs). The first GaN FET and the second GaN FET form a high-speed GaN bridge arm, which can improve the inductor current waveform.

In one embodiment, the third power switch S3 and the fourth power switch S4 are silicon carbide field effect transistors (SiCFETs). The first SiC FET and the second SiC FET form a power frequency chopper SiC bridge arm, which can reduce switching loss.

In one embodiment, the input voltage signal unit includes: a first input resistor R4, a second input resistor R5, a third input resistor R6, a fourth input resistor R7, a first diode D1 and a second diode D2, please Refer to Figure 1. The first end of the first input resistor R1 is connected to the neutral line N of the AC power source _ui , the second end of the first input resistor R4 is connected to the first end of the second input resistor R5, and the second end of the second input resistor R5 ground. The node between the first input resistor R4 and the second input resistor R5 is also connected to the first end of the first diode; the first end of the third input resistor R6 is connected to the live wire L of the AC power supply _ui , and the third input resistor R6 The second end of the fourth input resistor R7 is connected to the first end of the fourth input resistor R7, and the other end of the fourth input resistor R7 is grounded; the node between the third input resistor R6 and the fourth input resistor R7 is also connected to the first diode D1. The two ends form a common point P1; the node between the second input resistor R5 and the first diode D1 is also connected to the first end of the second diode D2 to form a common point N1, and the fourth input resistor R7 is connected to the first diode D1. The node between the diodes D1 is also connected to the second end of the second diode D2, and the common point N1 and P1 generate the input voltage signal u _i1 .

In a specific example, the value of each symbol in the above-mentioned embodiment is:

Input voltage: 220Vac@50Hz;

Output voltage: 385V;

Output power: several hundred watts ~ 3.3kW;

Switching frequency: depends on the hysteresis width, the minimum is 85kHz, and the maximum is 350kHz;

Resistance R1, R2: 1MΩ;

Resistor R3: 25.8kΩ;

Resistors R4, R6: 2x360kΩ;

Resistance R5, R7: 220Ω;

Shunt resistance R8, R10: 10mΩ;

Resistors R9, R11: 100Ω;

Diodes D1～D2: 1N4148;

Capacitor C1: 1.0μF;

Capacitor C2: 3x470μF;

Capacitor C3: 1nF;

Capacitor C4: 1nF;

Inductance L1: 250μH;

GaN FET S1, S2: 25A@85℃, 650V;

SiC FET S3, S4: 25A@85℃, 650V.

The working principle of the totem pole PFC inductor current synthesis circuit of the above embodiment is as follows:

(1) The second shunt resistor R10 flows through the complete inductor current in the positive half cycle, and the voltage of the second shunt resistor R10 is negative;

(2) The first shunt resistor R8 flows through the negative half-cycle drop inductor current, and the voltage of the first shunt resistor R8 is negative, so it is necessary to synthesize a complete negative half cycle drop inductor current;

In the negative half cycle of the grid voltage, the first functional unit inputs the detected value of the instantaneous value of the voltage. After dividing the detected value by the inductance value L1, the slope of the rising inductor current in the negative half cycle can be obtained. When the negative half cycle decreasing inductor current is known, it can be Calculate the negative half cycle falling inductor current waveform, then get the complete negative half cycle inductor current;

(3) After obtaining the inductor current waveform of the positive half cycle and the negative half cycle, the inductor current waveform of the whole cycle is obtained, which is used for the subsequent inner loop current control and overcurrent protection.

In an embodiment, a totem-pole PFC inductor current synthesis device is also provided, which includes the totem-pole PFC inductor current synthesis circuit described in any of the above embodiments.

The inductance current of the existing totem-pole PFC generally uses a Hall current sensor and a linear isolation amplifier, which requires an auxiliary power supply, and has the problems of high cost and large volume. The totem-pole PFC inductor current synthesis in the embodiment of the present invention adopts the method of connecting shunt resistors (R8, R10) in series between the sources of the two lower tube field effect transistors and the ground, and the inductor current is synthesized or reconstructed by measuring the voltage of the shunt resistors .

In the description of this specification, references to the terms "an embodiment", "an example", "specific implementation", "an example", etc. refer to the specific features described in conjunction with the embodiment or example, A structure, material, or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Only preferred embodiments of the present invention are disclosed herein, and the present specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, but not to limit the present invention. Any modifications and changes made by those skilled in the art within the scope of the description should fall within the protection scope of the present invention.

Claims (10)

1. A totem-pole PFC inductive current synthesis circuit is characterized by comprising: the power circuit module and the control circuit module; wherein,

the power circuit module includes: the circuit comprises an alternating current power supply, an inductor, an input voltage signal unit and a totem-pole PFC circuit unit;

the totem pole PFC circuit unit includes: the power supply comprises a first power switch, a second power switch, a third power switch, a fourth power switch, a first shunt resistor and a second shunt resistor;

the live wire of the alternating current power supply is connected with the input end of the input voltage signal unit, and the live wire of the alternating current power supply is also connected with the first end of the inductor;

the source electrode of the first power switch is connected with the drain electrode of the second power switch, and a node between the source electrode of the first power switch and the drain electrode of the second power switch is connected with the second end of the inductor;

the source electrode of the third power switch is connected with the drain electrode of the fourth power switch, and a node between the source electrode of the third power switch and the drain electrode of the fourth power switch is connected with a zero line of the alternating current power supply;

the drain electrode of the first power switch is connected with the drain electrode of the third power switch;

the source electrode of the second power switch is connected with the first end of the first shunt resistor, and the second end of the first shunt resistor is grounded;

the source electrode of the fourth power switch is connected with the first end of the second shunt resistor, and the second end of the second shunt resistor is grounded;

the control circuit module includes: the device comprises an input voltage detection unit, a first output voltage detection unit, a second output voltage detection unit and an inductive current synthesis unit;

the output end of the input voltage signal unit is connected with the input end of the input voltage detection unit;

the input end of the first output voltage detection unit is connected with two ends of the first shunt resistor;

the input end of the second output voltage detection unit is connected with two ends of the second shunt resistor;

the output end of the input voltage detection unit, the output end of the first output voltage detection unit and the output end of the second output voltage detection unit are respectively connected with the input end of the inductive current synthesis unit, and the output end of the inductive current synthesis unit is configured to be capable of outputting synthesized inductive current.

2. The totem-pole PFC inductor current synthesizing circuit of claim 1, wherein the inductor current synthesizing unit comprises: the device comprises a polarity judgment unit, a slope calculation unit, a rising current calculation unit, a multiplier, a first adder and a second adder; wherein,

the output end of the input voltage detection unit is connected with the input end of the polarity judgment unit;

the output end of the polarity judging unit is connected with the first input end of the multiplier;

the output end of the first output voltage detection unit is connected with the second input end of the multiplier;

the output end of the multiplier is connected with the first input end of the rising current calculating unit;

the node between the input voltage detection unit and the polarity judgment unit is also connected with the input end of the slope calculation unit;

the output end of the slope calculation unit is connected with the second input end of the rising current calculation unit;

the output end of the rising current calculating unit is connected with the first input end of the first adder;

the node between the multiplier and the rising current calculation unit is also connected with the second input end of the first adder;

the output end of the first adder is connected with the first input end of the second adder;

the output end of the second output voltage detection unit is connected with the second input end of the second adder;

the second adder is configured to be capable of outputting a resultant inductor current.

3. The totem-pole PFC inductor current synthesizing circuit of claim 2, wherein the power circuit module further comprises: a first capacitor;

the totem-pole PFC circuit unit further comprises: the second capacitor, the first resistance unit and the second resistance unit; wherein,

the first end of the first capacitor is connected with the first end of the inductor, and a node between the source electrode of the third power switch and the drain electrode of the fourth power switch is also connected with the second end of the first capacitor;

the node between the drain electrode of the first power switch and the drain electrode of the third power switch is connected with the first end of the first resistance unit, the second end of the first resistance unit is connected with the first end of the second resistance unit, and the second end of the second resistance unit is grounded.

4. The totem-pole PFC inductor current synthesizing circuit of claim 3, wherein the totem-pole PFC circuit unit further comprises: the first filtering unit and the second filtering unit; wherein,

the first end of the first shunt resistor is connected with the input end of the first output voltage detection unit through the first filtering unit;

and the first end of the second shunt resistor is connected with the input end of the second output voltage detection unit through the second filtering unit.

5. The totem-pole PFC inductor current synthesis circuit of claim 4, wherein the first filtering unit comprises: a first filter resistor and a first filter capacitor; the second filtering unit includes: a second filter resistor and a second filter capacitor; wherein,

a first end of the first filter resistor is connected with a first end of the first shunt resistor, a second end of the first filter resistor is connected with a first end of the first filter capacitor, a node between the first filter resistor and the first filter capacitor is also connected with an input end of the first output voltage detection unit, and a second end of the first filter capacitor is grounded;

the first end of the second filter resistor is connected with the first end of the second shunt resistor, the second end of the second filter resistor is connected with the first end of the second filter capacitor, a node between the second filter resistor and the second filter capacitor is further connected with the input end of the second output voltage detection unit, and the second end of the second filter capacitor is grounded.

6. The totem-pole PFC inductor current synthesizing circuit of claim 3, wherein the first resistance unit comprises: a plurality of resistors connected in series in sequence; and/or the presence of a gas in the gas,

the second resistance unit includes: a plurality of resistors connected in series in sequence.

7. The totem-pole PFC inductor current synthesizing circuit of any one of claims 1 to 6, wherein the first power switch and the second power switch are gallium nitride field effect transistors.

8. The totem-pole PFC inductor current synthesizing circuit of claim 7, wherein the third power meter switch and the fourth power switch are silicon carbide field effect transistors.

9. The totem-pole PFC inductor current synthesis circuit of any one of claims 1 to 6, wherein the input voltage signal unit comprises: the circuit comprises a first input resistor, a second input resistor, a third input resistor, a fourth input resistor, a first diode and a second diode; wherein,

the first end of the first input resistor is connected with a zero line of the alternating current power supply, the second end of the first input resistor is connected with the first end of the second input resistor, and the second end of the second input resistor is grounded;

the node between the first input resistor and the second input resistor is also connected with the first end of the first diode;

the first end of the third input resistor is connected with the live wire of the alternating current power supply, the second end of the third input resistor is connected with the first end of the fourth input resistor, and the other end of the fourth input resistor is grounded;

the node between the third input resistor and the fourth input resistor is also connected with the second end of the first diode;

the node between the second input resistor and the first diode is also connected with the first end of the second diode;

the node between the fourth input resistor and the first diode is also connected with the second end of the second diode;

the node of the second input resistor connected with the second diode is also connected with the first input end of the input voltage detection unit;

and the node of the third input resistor connected with the first diode is also connected with the second input end of the input voltage detection unit.

10. A totem-pole PFC inductor current synthesizing device, comprising: the totem-pole PFC inductor current synthesizing circuit as claimed in any one of claims 1 to 9.

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