CN112994504A

CN112994504A - Primary side power feedback circuit and method applied to wireless charging system

Info

Publication number: CN112994504A
Application number: CN202110520682.9A
Authority: CN
Inventors: 何智; 李健维; 胡锦敏
Original assignee: Shenzhen Hertz Innovation Technology Co ltd
Current assignee: Shenzhen Hertz Innovation Technology Co ltd
Priority date: 2021-05-13
Filing date: 2021-05-13
Publication date: 2021-06-18

Abstract

The invention provides a primary side power feedback circuit and a method applied to a wireless charging system, wherein the primary side power feedback circuit comprises: the device comprises a transmitting module, a control module, a driving module and a receiving module; the transmitting module comprises a filter circuit, a half-bridge SS inverter circuit, an input current sampling circuit, a differential amplifying circuit, an input voltage sampling circuit and a transmitting circuit. According to the invention, through the cooperation of the transmitting module, the control module, the driving module and the receiving module and the assistance of the filter circuit, the half-bridge SS inverter circuit, the input current sampling circuit, the differential amplification circuit, the input voltage sampling circuit and the transmitting circuit in the receiving module, the transmitting module is subjected to primary side power feedback control and is connected with the receiving module, and energy is output to the receiving module, so that the wireless charging function of the transmitting module and the receiving module is realized, and the stability of a wireless charging system is improved conveniently.

Description

Primary side power feedback circuit and method applied to wireless charging system

Technical Field

The invention belongs to the technical field of wireless charging, and particularly relates to a primary side power feedback circuit and a primary side power feedback method applied to a wireless charging system.

Background

The wireless charging system is a small-sized control system, and the output of the receiving controller realizes the function of constant voltage or constant current through a certain control means. The common control mode is to control the duty ratio or frequency of the MOS transistor of the high-frequency inverter circuit of the transmission controller to realize constant current and constant voltage. Due to the physical and electrical isolation between the transmitting end and the receiving end, the voltage and current signals of the receiving end are generally transmitted to the transmitting end by using wireless communication, which has the biggest defect that the transmission delay is very large, generally about 50ms, the same wireless communication is unstable, and packet loss is relatively easy to occur. It is thus clear that there is the poor problem of stability in current wireless charging system.

Disclosure of Invention

The embodiment of the invention provides a primary side power feedback circuit applied to a wireless charging system, and aims to solve the problem of poor stability of the existing wireless charging system.

The embodiment of the invention provides a primary side power feedback circuit applied to a wireless charging system, which comprises: the device comprises a transmitting module, a control module, a driving module and a receiving module;

the transmitting module comprises a filter circuit, a half-bridge SS inverter circuit, an input current sampling circuit, a differential amplifying circuit, an input voltage sampling circuit and a transmitting circuit;

the filter circuit is respectively and electrically connected with an alternating current power supply, the half-bridge SS inverter circuit, the input current sampling circuit, the differential amplification circuit, the input voltage sampling circuit, the transmitting circuit and a grounding end;

the differential amplification circuit is respectively and electrically connected with the alternating current power supply, the input current sampling circuit, the half-bridge SS inverter circuit, the transmitting circuit, the control module and a grounding end;

the input voltage sampling circuit is also electrically connected with the half-bridge SS inverter circuit, the transmitting circuit, the control module and a grounding end respectively;

the control module is also electrically connected with the driving module;

the driving module is also electrically connected with the half-bridge SS inverter circuit;

the transmitting circuit is also connected with the receiving module primary side power feedback control and is electrically connected with a grounding terminal.

Furthermore, the filter circuit comprises an inductor L1 and a capacitor C1;

one end of the inductor L1 is electrically connected to the positive electrode of the ac power supply, and the other end of the inductor L1 is electrically connected to one end of the capacitor C1, the input voltage sampling circuit, the half-bridge SS inverter circuit, and the transmitter circuit, respectively;

one end of the capacitor C1 is also electrically connected to the half-bridge SS inverter circuit and the transmitter circuit, and the other end of the capacitor C1 is electrically connected to the input current sampling circuit, the differential amplifier circuit, the transmitter circuit, and the ground terminal.

Further, the half-bridge SS inverter circuit includes: a first switching tube Q1 and a second switching tube Q2;

a first end of the first switch tube Q1 is electrically connected to a connection line between the inductor L1 and the capacitor C1, a second end of the first switch tube Q1 is electrically connected to the first driving end of the driving module, and a third end of the first switch tube Q1 is electrically connected to the first end of the second switch tube Q2 and the transmitting circuit, respectively;

the first end of the second switch tube Q2 is further electrically connected to the transmitting circuit, the second end of the second switch tube Q2 is electrically connected to the second driving end of the driving module, and the third end of the second switch tube Q2 is electrically connected to the transmitting circuit, the input current sampling circuit, the capacitor C1, the differential amplifying circuit, and the ground terminal, respectively.

Still further, the differential amplification circuit includes: the circuit comprises a resistor R3, a resistor R4, a resistor R5, a resistor R6, an operational amplifier and a capacitor C7;

one end of the resistor R3 is electrically connected with the negative electrode of the alternating current power supply and the input current sampling circuit respectively, and the other end of the resistor R3 is electrically connected with the negative electrode input end of the operational amplifier and one end of the resistor R5 respectively;

the other end of the resistor R5 is electrically connected with the output end of the operational amplifier and one end of the resistor R6 respectively;

one end of the resistor R6 is also electrically connected with the output end of the operational amplifier, the other end of the resistor R6 is electrically connected with one end of the capacitor C7 and the control module respectively, and the other end of the capacitor C7 is grounded;

one end of the resistor R4 is electrically connected to the input current sampling circuit, the capacitor C1, the third end of the second switch tube Q2, the transmitting circuit, and the ground terminal, respectively;

the other end of the resistor R4 is electrically connected with the positive input end of the operational amplifier.

Furthermore, the input voltage sampling circuit comprises a resistor R7 and a resistor R8;

one end of the resistor R7 is electrically connected to the connection line between the inductor L1 and the capacitor C1, and one end of the resistor R7 is also electrically connected to the first end of the first switch transistor Q1 and the transmitting circuit, respectively;

the other end of the resistor R7 is electrically connected with one end of the resistor R8 and the control module respectively;

the other end of the resistor R8 is electrically connected to ground.

Still further, the transmit circuit includes: a capacitance C2, a capacitance C3, and a transmission coil TX;

one end of the capacitor C2 is electrically connected to the connection line between the inductor L1 and the capacitor C1, one end of the capacitor C2 is also electrically connected to the first end of the first switch transistor Q1 and the end of the resistor R7 away from the resistor R8, and the other end of the capacitor C2 is electrically connected to one end of the capacitor C3 and the end of the transmitting coil TX;

the other end of the capacitor C3 is electrically connected with the third end of the second switching tube, the input current sampling circuit, the resistor R4, the capacitor C1 and the ground terminal respectively;

the other end of the transmitting coil TX is electrically connected to the third end of the first switch tube Q1 and the first end of the second switch tube Q2 respectively;

and the transmitting coil TX is connected with the primary side power feedback control of the receiving module.

Still further, the receiving module includes: the receiving coil RX, the capacitor C4, the diode D1, the diode D2, the diode D3, the diode D4, the capacitor C5 and the resistor Rload;

the receiving coil RX is connected with a primary side power feedback control of the transmitting coil TX, one end of the receiving coil RX is electrically connected with one end of the capacitor C4, and the other end of the receiving coil RX is respectively electrically connected with the anode of the diode D2 and the cathode of the diode D3;

the other end of the capacitor C4 is electrically connected to the anode of the diode D1 and the cathode of the diode D4 respectively;

the other end of the diode D1 is electrically connected to the cathode of the diode D2, one end of the capacitor C5 and one end of the resistor Rload, respectively;

the anode of the diode D3 is electrically connected to the other end of the capacitor C5, the other end of the resistor Rload, and the anode of the diode D4, respectively.

The embodiment of the invention also provides a primary side power feedback method applied to the wireless charging system, which is used in the primary side power feedback circuit applied to the wireless charging system provided by the embodiment, and the method comprises the following steps:

acquiring the actual input power of the transmitting module;

comparing the actual input power with a preset first input power and a preset second input power to obtain a comparison result, wherein the preset first input power is smaller than the preset second input power;

adjusting the switching frequency of the half-bridge SS inverter circuit according to the comparison result;

and carrying out amplitude limiting processing on the adjusted switching frequency to obtain a corresponding driving signal so as to drive the transmitting circuit to carry out primary side power feedback control on the receiving module to output energy.

Further, the step of adjusting the switching frequency of the half-bridge SS inverter circuit according to the comparison result comprises:

if the actual input power is smaller than the preset first input power, reducing the switching frequency;

if the actual input power is larger than the preset second input power, increasing the switching frequency;

and if the actual input power is greater than the preset first input power and less than the preset second input power, keeping the switching frequency unchanged.

Further, the step of obtaining the actual input power of the transmitting module comprises:

collecting input current and input voltage of the transmitting module;

and multiplying the input current and the input voltage, and dividing the multiplied input current and the multiplied input voltage by a sampling ratio to obtain the actual input power.

The invention achieves the following beneficial effects: through the cooperation between the transmitting module, the control module, the driving module and the receiving module and the assistance of the filter circuit, the half-bridge SS inverter circuit, the input current sampling circuit, the differential amplification circuit, the input voltage sampling circuit and the transmitting circuit in the receiving module, the transmitting module is subjected to primary side power feedback control and is connected with the receiving module, energy is output to the receiving module, and then the wireless charging function of the transmitting module and the receiving module is realized. The stability of wireless charging system is convenient for improve.

Drawings

Fig. 1 is a schematic structural diagram of a primary side power feedback circuit applied to a wireless charging system according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of a primary side power feedback circuit applied to a wireless charging system according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a simulation of a transmitting module according to an embodiment of the present invention;

FIG. 4 is a simulation diagram of a control module and a driving module according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a simulation of a differential amplifier circuit according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a simulation of a receiving module according to an embodiment of the present invention;

FIG. 7 is a graph of input power variation provided by an embodiment of the present invention;

FIG. 8 is a graph of output power variation provided by an embodiment of the present invention;

FIG. 9 is a diagram illustrating a variation of a switching frequency according to an embodiment of the present invention;

fig. 10 is a flowchart of a primary power feedback method applied to a wireless charging system according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example one

As shown in fig. 1, fig. 1 is a schematic structural diagram of a primary power feedback circuit applied to a wireless charging system according to an embodiment of the present invention.

The primary side power feedback circuit applied to the wireless charging system comprises a transmitting module 1, a control module 2, a driving module 3 and a receiving module 4; the transmitting module 1 comprises a filter circuit 11, a half-bridge SS inverter circuit 12, an input current sampling circuit 13, a differential amplifying circuit 14, an input voltage sampling circuit 15 and a transmitting circuit 16; the filter circuit 11 is respectively electrically connected with the alternating current power supply 5, the half-bridge SS inverter circuit 12, the input current sampling circuit 13, the differential amplification circuit 14, the input voltage sampling circuit 15, the transmitting circuit 16 and a grounding end; the differential amplification circuit 14 is respectively electrically connected with the alternating current power supply 5, the input current sampling circuit 13, the half-bridge SS inverter circuit 12, the transmitting circuit 16, the control module 2 and a grounding end; the input voltage sampling circuit 15 is also electrically connected with the half-bridge SS inverter circuit 12, the transmitting circuit 16, the control module 2 and the ground terminal respectively; the control module 2 is also electrically connected with the driving module 3; the driving module 3 is also electrically connected with a half-bridge SS inverter circuit 12; the transmitting circuit 16 is also connected to the primary power feedback control of the receiving module 4 and to ground.

Specifically, the primary power feedback circuit applied to the wireless charging system is described by taking a half-bridge SS topology as an example, but is not limited to the half-bridge SS topology, and may also be a wireless charging topology such as an LCC-S LCC-LCC.

As shown in fig. 2, the control module 2 includes an MCU controller. The MCU controller includes an input current sampling interface ADC1 and an input voltage sampling interface ADC 0. The input current sampling interface ADC1 is used for sampling the input current of the transmitting module 1. The input voltage sampling interface ADC0 is used for sampling the input voltage of the transmitting module 1. The MCU controller also comprises a driving interface for outputting a driving signal to drive the driving circuit.

As shown in fig. 2, the input current sampling circuit 13 includes a sampling resistor R1. The sampling resistor R1 is a high-precision sampling resistor (an alloy resistor with a precision of 1% is usually selected as the sampling resistor) for sampling the input current of the transmitting module 1. The input current of the transmitter module 1 is basically the dc input current of the transmitter module 1. The sampling resistor R1 transmits the sampled input current to the differential amplifier circuit 14 for amplification, and then the amplified input current is provided to the input current sampling interface ADC1 of the control module 2 for sampling.

As shown in fig. 2, the driving module 3 includes a first driving terminal DrA and a second driving terminal DrB, and both the first driving terminal DrA and the second driving terminal DrB are electrically connected to the half-bridge SS inverter circuit 12. Thus, the driving module 3 can drive the half-bridge SS inverter circuit 12 to operate.

In the embodiment of the present invention, the filter circuit 11 includes an inductor L1 and a capacitor C1; one end of an inductor L1 is electrically connected with the positive electrode of the alternating current power supply 5, and the other end of the inductor L1 is electrically connected with one end of a capacitor C1, the input voltage sampling circuit 15, the half-bridge SS inverter circuit 12 and the transmitting circuit 16 respectively; one end of the capacitor C1 is also electrically connected to the half-bridge SS inverter circuit 12 and the transmitter circuit 16, respectively, and the other end of the capacitor C1 is electrically connected to the input current sampling circuit 13, the differential amplifier circuit 14, the transmitter circuit 16, and the ground, respectively.

Specifically, in the filter circuit 11, the inductor L1 and the capacitor C1 form an LC filter for filtering the switching ripple current generated by the half-bridge SS inverter circuit 12. Wherein the cutoff frequency of the LC filter is calculated by the following equation (1), and the cutoff frequency is selected according to the switching frequency of the half-bridge SS inverter circuit 12, and is typically selected to be 1/10 slightly less than the switching frequency, for example, if the switching frequency is 70KHz, the cutoff frequency of the LC filter is selected to be slightly less than 7 KHz.

The formula (1) is as follows.

（1）

Wherein the content of the first and second substances,

for the cut-off frequency of the LC filter, L1 is the inductance of inductor L1, and C1 is the capacitance of capacitor C1.

In the embodiment of the present invention, the half-bridge SS inverter circuit 12 includes: a first end (a d pole and a drain pole) of the first switch tube Q1 is electrically connected with a connecting line between the inductor L1 and the capacitor C1, a second end (a g pole and a grid pole) of the first switch tube Q1 is electrically connected with a first driving end DrA of the driving module 3, and a third end (an s pole and a source pole) of the first switch tube Q1 is respectively electrically connected with a first end of the second switch tube Q2 and the transmitting circuit 16; the first end (d pole, drain) of the second switch Q2 is further electrically connected to the emission circuit 16, the second end (g pole, gate) of the second switch Q2 is electrically connected to the second driving end DrB of the driving module 3, and the third end (s pole, source) of the second switch Q2 is electrically connected to the emission circuit 16, the input current sampling circuit 13, the capacitor C1, the differential amplifier circuit 14, and the ground terminal, respectively.

Specifically, when the first switch Q1 and the second switch Q2 in the half-bridge SS inverter circuit 12 respectively receive the driving signals from the first driving terminal DrA and the second driving terminal DrB in the driving module 3, the first switch Q1 and the second switch Q2 are turned on, so that the half-bridge SS inverter circuit 12 operates normally. Further, the transmitting circuit 16 is enabled to work normally and connected with the primary side power feedback control of the receiving module 4, so that energy transmission between the transmitting module 1 and the receiving module 4 is realized, and wireless charging is realized.

In the embodiment of the present invention, as shown in fig. 2, the differential amplifying circuit 14 includes: the circuit comprises a resistor R3, a resistor R4, a resistor R5, a resistor R6, an operational amplifier and a capacitor C7; one end of the resistor R3 is electrically connected with the negative electrode of the alternating current power supply 5 and the input current sampling circuit 13, and the other end of the resistor R3 is electrically connected with the negative electrode input end of the operational amplifier and one end of the resistor R5; the other end of the resistor R5 is electrically connected with the output end of the operational amplifier and one end of the resistor R6 respectively; one end of the resistor R6 is also electrically connected with the output end of the operational amplifier, the other end of the resistor R6 is respectively electrically connected with one end of the capacitor C7 and the control module 2, and the other end of the capacitor C7 is grounded; one end of the resistor R4 is electrically connected to the input current sampling circuit 13, the capacitor C1, the third end of the second switch tube Q2, the transmitting circuit 16 and the ground terminal, respectively; the other end of the resistor R4 is electrically connected with the positive input end of the operational amplifier.

Specifically, the differential amplifier circuit 14 is configured to amplify the input current sampled by the sampling circuit, and then provide the amplified input current to the input current sampling interface ADC1 of the MCU controller for sampling, so as to obtain the input current of the transmitting module 1.

In the embodiment of the present invention, as shown in fig. 2, the input voltage sampling circuit 15 includes a resistor R7 and a resistor R8; one end of the resistor R7 is electrically connected to the connection line between the inductor L1 and the capacitor C1, and one end of the resistor R7 is also electrically connected to the first end of the first switch tube Q1 and the transmitting circuit 16, respectively; the other end of the resistor R7 is electrically connected with one end of the resistor R8 and the control module 2 respectively; the other end of the resistor R8 is electrically connected to ground.

Specifically, the resistor R7 and the resistor R8 are both voltage-dividing resistors. The resistor R7 and the resistor R8 form a voltage dividing circuit, so that the input voltage of the transmission module 1 is directly divided by the resistor R7 and the resistor R8 of the voltage dividing resistor, and then is provided to the input voltage sampling interface ADC0 of the MCU controller in the control module 2 for sampling, thereby obtaining the input voltage of the transmission module 1.

In the embodiment of the present invention, as shown in fig. 2, the transmission circuit 16 includes: a capacitance C2, a capacitance C3, and a transmission coil TX; one end of a capacitor C2 is electrically connected to a connection line between the inductor L1 and the capacitor C1, one end of the capacitor C2 is also electrically connected to a first end of the first switch transistor Q1 and one end of the resistor R7 far away from the resistor R8, and the other end of the capacitor C2 is electrically connected to one end of the capacitor C3 and one end of the transmitting coil TX; the other end of the capacitor C3 is electrically connected with the third end of the second switch tube, the input current sampling circuit 13, the resistor R4, the capacitor C1 and the ground end respectively; the other end of the transmitting coil TX is electrically connected to the third end of the first switch Q1 and the first end of the second switch Q2 respectively; the transmitting coil TX is connected to the primary side power feedback control of the receiving module 4.

Specifically, after the transmitting circuit 16 works, the transmitting coil TX is connected with the primary side power feedback control of the receiving module 4, and the transmitting coil TX outputs constant power to the receiving module 4 through the primary side power feedback control, so that energy transmission between the transmitting module 1 and the receiving module 4 is realized, and wireless charging is completed.

In the embodiment of the present invention, as shown in fig. 2, the receiving module 4 includes: the receiving coil RX, the capacitor C4, the diode D1, the diode D2, the diode D3, the diode D4, the capacitor C5 and the resistor Rload; the receiving coil RX is connected with the primary side power feedback control of the transmitting coil TX, one end of the receiving coil RX is electrically connected with one end of the capacitor C4, and the other end of the receiving coil RX is respectively electrically connected with the anode of the diode D2 and the cathode of the diode D3; the other end of the capacitor C4 is electrically connected to the anode of the diode D1 and the cathode of the diode D4, respectively; the other end of the diode D1 is electrically connected to the cathode of the diode D2, one end of the capacitor C5, and one end of the resistor Rload, respectively; the anode of the diode D3 is electrically connected to the other end of the capacitor C5, the other end of the resistor Rload, and the anode of the diode D4, respectively.

Specifically, after the receiving coil RX of the receiving module 4 is connected to the transmitting coil TX of the transmitting circuit 16 by primary power feedback control, energy (constant power) transmitted by the transmitting coil TX can be received to charge the battery, thereby implementing a wireless charging function.

In the embodiment of the invention, the invention provides a simulation schematic diagram of primary side constant power control of a half-bridge ss topology, as shown in fig. 3 to 6.

On the basis of the simulation schematics of fig. 3-6, the simulation parameters used by the embodiment of the invention are as follows:

input voltage Vin = 72V;

input filter inductance L1 (inductance L1) =3.3 uH;

input filter capacitance C1 (capacitance C1) =220 uF;

inductance Tx =45uH of the transmitting coil Tx;

the capacity of the transmit resonance capacitance (capacitance C2, capacitance C3) C2= C3=66 nF;

the inductance RX =30uH of the receiving coil RX;

the capacity of the receive resonance capacitance (capacitance C4) C4=181 nF;

the coupling coefficient was set to 0.2;

input current sampling resistance R1=15m Ω;

values of the resistor R3, the resistor R4, the resistor R5, the resistor R6, and the capacitor C7 in the input current sampling differential amplifier circuit 14 are R3= R4=560 Ω, R5=20K Ω, R6=1K Ω, and C7=10nF, respectively;

the values of the resistor R7 and the resistor R8 in the input voltage sampling circuit 15 are R7=69K Ω, R8=2.5K Ω, respectively;

the rechargeable battery in the receiving module 4 is connected with a 24V battery, and the internal resistance of the battery is set to be 50m omega.

The control code of the MCU controller used in this embodiment is as follows:

#########################################################

# Version:1.01 r

##########################################################

---------------------------------------------------------------------

# EPWM generate code

#--------------------------------------------------------------------

element template swiss_dsp_ivs_compare ADCINA0 ADCINA1 ADCINA2 ADCINA3 ADCINA4 GROUND Vdcset TestPort TestPort1 TestPort2 fcal Updata Enable DCePWM1A DCePWM1B DCePWM2A DCePWM2B DCePWM3A DCePWM3B DCePWM4A DCePWM4B DCePWM5A DCePWM5B DCePWM6A DCePWM6B=PRD,dtime,f_DSP,Cf,Vdc_LoopK3,Vdc_LoopK4,Idc_LoopK3,Idc_LoopK4,powerset

input nu Vdcset

State logic_4

DCePWM1A,DCePWM1B,DCePWM2A,DCePWM2B,DCePWM3A,DCePWM3B,DCePWM4A,DCePWM4B,DCePWM5A, DCePWM5B, DCePWM6A, DCePWM6B,Updata,Enable,fcal

electrical ADCINA0

electrical ADCINA1

electrical ADCINA2

electrical ADCINA3

electrical ADCINA4

electrical TestPort

electrical TestPort1

electrical TestPort2

electrical GROUND

number PRD=10e-6, # the swiss rectifier switch period

dtime=300e-9, # dead-time

f_DSP=60000000, # frequency of DSP

Cf=13.6e-6,

Vdc_LoopK3=0,

Vdc_LoopK4=0,

Idc_LoopK3=0,

Idc_LoopK4=0,

powerset=100

{

# foreign LOOP_IVSCOMP

state logic_4 PWM1A=l4_0

State nu

tick1,tick2,tick3,tick4,tick5,tickUxy,tickUyz,TonP,Tontemp,ToffP,TonN,ToffN,TonP_N,TonP_Nx,DoffP,DoffN,flagUxy=0,flagUyz=0,timer=0,timerup=1,PioutP_Use=1,PioutN_Use=1,flagA=0,flagB=0,flagC=0,fs=85e3,Ton

State nu vADCINA0_USE, vADCINA1_USE,

vADCINA2_USE, vADCINA3_USE,vADCINA4_USE,vADCINA0_Mid, vADCINA1_Mid,vADCINA2_Mid,vADCINA_temp1, vADCINA_temp2,Icoil_uplimit=6*11/110,Icoil_downlimit=5.5*11/110,powerFB=0,Decfs=0

val v vADCINA0, vADCINA1, vADCINA2,vADCINA3,vADCINA4

val i iADCINA0, iADCINA1, iADCINA2,iADCINA3,iADCINA4

var i itg,itg1,itg2

#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# Input Voltage sample and IVS control

values{

vADCINA0 = v( ADCINA0, GROUND )

vADCINA1 = v( ADCINA1, GROUND )

vADCINA2 = v( ADCINA2, GROUND )

vADCINA3 = v( ADCINA3, GROUND )

vADCINA4 = v( ADCINA4, GROUND )

iADCINA0 = vADCINA0 / 100000000

iADCINA1 = vADCINA1 / 100000000

iADCINA2 = vADCINA2 / 100000000

iADCINA3 = vADCINA3 / 100000000

iADCINA4 = vADCINA4 / 100000000

}

equations{i( ADCINA0->GROUND ) += iADCINA0

i( ADCINA1->GROUND ) += iADCINA1

i( ADCINA2->GROUND ) += iADCINA2

i( ADCINA3->GROUND ) += iADCINA3

i( ADCINA4->GROUND ) += iADCINA4

i( TestPort->GROUND ) += itg

itg: v( TestPort ) - v( GROUND ) = fs

i( TestPort1->GROUND ) += itg1

itg1: v( TestPort1 ) - v( GROUND ) = powerFB

i( TestPort2->GROUND ) += itg2

itg2: v( TestPort2 ) - v( GROUND ) = Icoil_uplimit

}

when( event_on( fcal ) & ( fcal == l4_1 ) & (Enable == l4_1)) {

vADCINA0_USE = vADCINA0

vADCINA1_USE = vADCINA1

vADCINA2_USE = vADCINA2

vADCINA3_USE = 4096 * vADCINA3 / 3.2

vADCINA4_USE = 4096 * vADCINA4 / 3.2

powerFB=vADCINA2_USE*28.6*vADCINA1_USE*0.56*1000/300

if(fs>80){Decfs=2e3

}

if(fs<80){Decfs=0.5e3

}

if(fs<75){Decfs=0.25e3

}

if(powerFB>(powerset*1.1)){fs=fs+0.25e3

}

if(powerFB<powerset){fs=fs-Decfs

}

if(fs>100e3){fs=100e3

}

if(fs<65e3){fs=65e3

}

# vADCINA_temp1 = vADCINA0_USE - vADCINA1_USE

# vADCINA_temp2 = vADCINA0_USE - vADCINA2_USE

# vADCINA0_Mid=vADCINA_temp1*vADCINA_temp2

# vADCINA_temp1 = vADCINA1_USE - vADCINA0_USE

# vADCINA_temp2 = vADCINA1_USE - vADCINA2_USE

# vADCINA1_Mid= vADCINA_temp1 * vADCINA_temp2

# vADCINA_temp1 = vADCINA2_USE - vADCINA0_USE

# vADCINA_temp2 = vADCINA2_USE - vADCINA1_USE

# vADCINA2_Mid= vADCINA_temp1 * vADCINA_temp2

# if((vADCINA0_Mid<0)){

# Schedule_event(time,DCePWM3A,l4_1)

# Schedule_event(time+dtime,DCePWM3B,l4_0)

# Schedule_event(time+dtime,DCePWM4A,l4_0)

# }

# if((vADCINA1_Mid<0)){

# Schedule_event(time+dtime,DCePWM3A,l4_0)

# Schedule_event(time,DCePWM3B,l4_1)

# Schedule_event(time+dtime,DCePWM4A,l4_0)

# }

# if(vADCINA2_Mid<0){

# Schedule_event(time+dtime,DCePWM3A,l4_0)

# Schedule_event(time+dtime,DCePWM3B,l4_0)

# Schedule_event(time,DCePWM4A,l4_1)

# }

# (DoffP,DoffN,tickUxy,tickUyz,PioutP_Use,PioutN_Use,flagA,flagB,flagC) = LOOP_IVSCOMP(vADCINA0_USE,vADCINA1_USE,vADCINA2_USE,vADCINA3_USE,vADCINA4_USE,Vdcset,Vdc_LoopK3,Vdc_LoopK4,Idc_LoopK3,Idc_LoopK4,Cf,fs)

# TonP = (PioutP_Use/f_DSP) #The turn on time of the positive Mos

# ToffP = (PioutP_Use/f_DSP) #The turn off time of the positive Mos

# TonN = (PioutN_Use/f_DSP) #The turn on time of the Negative Mos

# ToffN = (PioutN_Use/f_DSP) #The turn off time of the Negative Mos

}

when ( ( event_on( Enable) )& ( Enable == l4_1) ) {

Schedule_event(time,DCePWM1A,l4_0)

Schedule_event(time,DCePWM1B,l4_0)

Schedule_event(time,DCePWM2A,l4_0)

Schedule_event(time,DCePWM2B,l4_0)

Schedule_event(time,DCePWM3A,l4_0)

Schedule_event(time,DCePWM3B,l4_0)

Schedule_event(time,DCePWM4A,l4_0)

Schedule_event(time,DCePWM4B,l4_0)

schedule_event(time+100n,tick1,1)

if (PRD > 0){

Ton=(0.5*PRD-dtime) #The turn on time of the upside Mos

# TonP = (PioutP_Use/f_DSP) #The turn on time of the positive Mos

# ToffP = (PioutP_Use/f_DSP) #The turn off time of the positive Mos

# TonN = (PioutN_Use/f_DSP) #The turn on time of the Negative Mos

# ToffN = (PioutN_Use/f_DSP) #The turn off time of the Negative Mos

}

#+++++++++++++++++++++++++++++++++++++++++++++++++++

# Updata the PRD and DTs value

#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# drive signal of one leg of the swiss Mos

when (event_on(tick1)) {

schedule_event(time+dtime,DCePWM1A,l4_1)

schedule_event(time,DCePWM1B,l4_0)

schedule_event(time+0.5/fs,DCePWM1A,l4_0)

schedule_event(time+0.5/fs+dtime,DCePWM1B,l4_1)

schedule_event(time+1/fs,tick1,1)

# schedule_event(time,tick2,1)

# Schedule_event(time+0.5/fs-TonP,tick3,1)

# Schedule_event(time+0.5/fs-TonN,tick4,1)

}

#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# when (event_on(tick2)) {

# schedule_event(time+0.5/fs,DCePWM1B,l4_1)

# schedule_event(time+0.5/fs,DCePWM5B,l4_1)

# Schedule_event(time+1/fs-dtime,DCePWM1B,l4_0)

# Schedule_event(time+1/fs-dtime,DCePWM5B,l4_0)

# }

#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# drive signal of another leg of the swiss Mos

# when (event_on(tick3)) {

# schedule_event(time,DCePWM2A,l4_1)

# schedule_event(time+0.5/fs-dtime,DCePWM2A,l4_0)

# Schedule_event(time+0.5/fs,DCePWM2B,l4_1)

# Schedule_event(time+1/fs-dtime,DCePWM2B,l4_0)

# }

#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# when (event_on(tick4)) {

# schedule_event(time,DCePWM6A,l4_1)

# schedule_event(time+0.5/fs-dtime,DCePWM6A,l4_0)

# Schedule_event(time+0.5/fs,DCePWM6B,l4_1)

# Schedule_event(time+1/fs-dtime,DCePWM6B,l4_0)

# }

}

specifically, the specific simulation results obtained from the simulation parameters and the control codes used are shown in fig. 7, 8, and 9. Fig. 7 is a diagram of an input power variation according to an embodiment of the present invention. Fig. 8 is a graph of output power variation according to an embodiment of the present invention. Fig. 9 is a diagram of a switching frequency variation according to an embodiment of the present invention. The simulation result shows that the input power constant power control function of the transmitting module 1 can be basically realized. The input power can reach the power set value of 240W under the control of the primary power feedback algorithm, the output power can be finally in a stable state, and the switching frequency is finally stabilized at 69.5 KHz.

In the embodiment of the present invention, through the cooperation between the transmitting module 1, the control module 2, the driving module 3, and the receiving module 4, and the assistance of the filter circuit 11, the half-bridge SS inverter circuit 12, the input current sampling circuit 13, the differential amplifier circuit 14, the input voltage sampling circuit 15, and the transmitting circuit 16 in the receiving module 4, the primary power feedback control is performed on the transmitting module 1 to connect with the receiving module 4, and energy is output to the receiving module 4, so as to implement the wireless charging function of the transmitting module 1 and the receiving module 4. The stability of wireless charging system is convenient for improve.

Example two

Referring to fig. 10, fig. 10 is a flowchart of a primary power feedback method applied to a wireless charging system according to an embodiment of the present invention. The primary side power feedback method applied to the wireless charging system comprises the following steps:

step 101, obtaining the actual input power of the transmitting module.

Specifically, step 101 includes:

and collecting the input current and the input voltage of the transmitting module.

And multiplying the input current by the input voltage, and dividing the multiplied input current by the sampling ratio to obtain the actual input power.

More specifically, the input current is substantially a direct current input current. The input current is obtained by sampling the input current by an input current sampling circuit, inputting the input current to a differential amplifying circuit for amplifying, and outputting the amplified input current to an input current sampling interface ADC1 of the MCU controller in the control module for sampling.

The input voltage is directly divided by the resistor R7 and the resistor R8 of the voltage dividing resistor, and then is provided to the input voltage sampling interface ADC0 of the MCU controller in the control module for sampling, thereby obtaining the input voltage of the transmitting module.

The acquired input current and the input voltage are multiplied in the MCU controller, and then divided by the sampling ratio to obtain the actual input power of the transmitting module, wherein the actual input power can be recorded as PowerFB, and the actual input power can be expressed as PowerFB. The sampling ratio is calculated from the input current sampling circuit and the input voltage sampling circuit.

Step 102, comparing the actual input power with a preset first input power and a preset second input power to obtain a comparison result, wherein the preset first input power is smaller than the preset second input power.

The preset first input power and the preset second input power are preset threshold values, and are used for judging whether the switching frequency is adjusted. The preset first input power may be represented as a first input power PowerSet. The preset second input power may be expressed as a second input power 1.1 × PowerSet.

Specifically, after the actual input power is obtained and compared with the preset first input power and the preset second input power, a comparison result is obtained, and after the preset first input power is smaller than the preset second input power, the actual power is respectively compared with the preset first input power and the preset second input power, and then the comparison result is obtained. The comparison may include the following: the actual input power PowerFB < first input power PowerSet, or the actual input power PowerFB > second input power 1.1 × PowerSet, or the first input power PowerSet < actual input power PowerFB < second input power 1.1 × PowerSet.

And 103, adjusting the switching frequency of the half-bridge SS inverter circuit according to the comparison result.

Specifically, step 103 includes:

and if the actual input power is smaller than the preset first input power, reducing the switching frequency.

And if the actual input power is larger than the preset second input power, increasing the switching frequency.

Specifically, a switching frequency threshold value can be preset, and when the switching frequency needs to be adjusted after the actual input power is compared with the preset first input power and the preset second input power, the switching frequency only needs to be adjusted to meet the preset switching frequency threshold value range, so that the influence of too large or too small switching frequency on the circuit can be avoided, and the stability of the wireless charging system is improved.

And step 104, carrying out amplitude limiting processing on the adjusted switching frequency to obtain a corresponding driving signal so as to drive the transmitting circuit to carry out primary side power feedback control on the receiving module to output energy.

Specifically, whether the switching frequency is subjected to reduction operation, rising operation or unchanged operation, the switching frequency is required to be subjected to upper and lower amplitude limiting processing operation, so that the driving interface of the MCU controller can be ensured to output a proper driving signal to drive the driving module to work, the driving module is prevented from being damaged, and the stability of the circuit is improved. Of course, the limiting amplitude may be preset to a threshold amplitude. The amplitude of the switching frequency after the lowering, raising and maintaining operations is limited to be within the amplitude threshold range.

In the embodiment of the invention, the actual input power of the transmitting module is obtained; comparing the actual input power with a preset first input power and a preset second input power to obtain a comparison result, wherein the preset first input power is smaller than the preset second input power; adjusting the switching frequency of the half-bridge SS inverter circuit according to the comparison result; and carrying out amplitude limiting processing on the adjusted switching frequency to obtain a corresponding driving signal so as to drive the transmitting circuit to carry out primary side power feedback control on the receiving module to output energy. Therefore, the wireless charging function between the transmitting module and the receiving module can be realized by a primary side power feedback method, and the stability of a wireless charging system is improved.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A primary side power feedback circuit applied to a wireless charging system is characterized by comprising: the device comprises a transmitting module, a control module, a driving module and a receiving module;

the control module is also electrically connected with the driving module;

2. The primary power feedback circuit for use in a wireless charging system of claim 1 wherein said filter circuit comprises an inductor L1 and a capacitor C1;

3. The primary power feedback circuit for use in a wireless charging system of claim 2 wherein said half bridge SS inverter circuit comprises: a first switching tube Q1 and a second switching tube Q2;

4. The primary power feedback circuit for use in a wireless charging system of claim 3 wherein said differential amplifier circuit comprises: the circuit comprises a resistor R3, a resistor R4, a resistor R5, a resistor R6, an operational amplifier and a capacitor C7;

5. The primary power feedback circuit applied to the wireless charging system of claim 4, wherein the input voltage sampling circuit comprises a resistor R7 and a resistor R8;

the other end of the resistor R8 is electrically connected to ground.

6. The primary power feedback circuit for use in a wireless charging system of claim 5 wherein said transmit circuit comprises: a capacitance C2, a capacitance C3, and a transmission coil TX;

7. The primary power feedback circuit for use in a wireless charging system of claim 6, wherein said receiving module comprises: the receiving coil RX, the capacitor C4, the diode D1, the diode D2, the diode D3, the diode D4, the capacitor C5 and the resistor Rload;

8. A primary side power feedback method applied to a wireless charging system, wherein the method is used in the primary side power feedback circuit applied to the wireless charging system according to any one of claims 1 to 7, and the method comprises the steps of:

acquiring the actual input power of the transmitting module;

9. The primary power feedback method as claimed in claim 8, wherein the step of adjusting the switching frequency of the half-bridge SS inverter circuit according to the comparison result comprises:

10. The primary power feedback method for a wireless charging system as claimed in claim 8, wherein said step of obtaining the actual input power of said transmitting module comprises:

collecting input current and input voltage of the transmitting module;