TWI729707B - Wireless power transferring system - Google Patents

Abstract

A wireless power transferring system includes a primary side LLC converter, a wireless transmitter and a secondary side converter. The primary side LLC converter rectifies a DC source and generates a first AC output through a rectifying circuit thereof, and triggers an LLC resonant circuit for generating energy. The secondary side converter receives energy and converts the first AC output to a DC output. Furthermore, a SPWM modulator can be adopted to convert the DC output to a second AC output in accordance with different situations. Therefore, energy transferring efficiency can be enhanced, and a DC load or an AC load can be selectively switched so as to increase the application flexibility of the wireless power transferring system.

Description

Wireless energy conversion system

The present invention relates to an energy conversion system; more particularly, the present invention relates to a wireless energy conversion system capable of switching output AC load or DC load.

In view of the rising awareness of environmental protection, the development of green energy technology has made wireless energy transmission technology increasingly valued. This kind of technology is generally common in special application environments, high safety considerations and high-precision instruments. However, with the recent development of technology, wireless charging products have been found in consumer products. Wireless transmission of electric energy can be divided into two types: contact type and non-contact type. The contact system belongs to the use of metal contacts to connect and transmit power, such as various chargers, power supplies, and sockets for household appliances. The non-contact system uses an induction electric field to transmit electric energy, and can be used without a line connection. This is common in mobile phone wireless chargers, small household appliances, electric vehicles, light rail power supplies, etc. The advantages of the conventional contact type transmission of electric energy are higher efficiency and easier installation, but there are still disadvantages. For example, the metal contact parts used by the product may cause risks due to corrosion caused by poor contact, sparks during contact may cause fire or flashover, restricted by the influence of weather, or humid places. In order to solve the above-mentioned safety, environmental protection and other issues, non-contact The wireless power transmission technology has been paid more and more attention. This is due to the fact that it is less restricted by climate or environment, has no contact metal corrosion loss, does not need to be plugged and removed, there is no danger of electric shock or leakage, and the body maintenance loss is less. The advantage of reduced maintenance frequency.

In special applications, such as underwater oil well exploration operations, coal mines and other pit excavations, and in highly explosive gas and flammable liquids or humid environments, if electrical appliances are used, an electric arc is likely to cause an explosion at the moment of power-on, wireless energy transmission The technology can supply power under the water surface and in dangerous areas without arcs and sparks, which can improve safety. In the terminal area, due to the high salt content in the air, if the contact-type power supply is used, the connection device is likely to rust, resulting in a decline in power transmission capacity and efficiency, and even more serious, will cause electric leakage and electric shock risks. In addition, it can improve the problems of transmission line loss and adapter interface loss in consumer products.

Wireless power transfer (Wireless Power Transfer, WPT) is generally realized through Faraday electromagnetic induction, which is more convenient and safer than conventional contact feeding, but the current efficiency of inductive coupling energy transfer can be provided. It is less than 75%, which is obviously lower than the traditional contact transmission efficiency. Therefore, how to improve energy conversion efficiency is a top priority.

The present invention provides a wireless energy conversion system with high conversion efficiency. The primary-side LLC converter transmits energy to the secondary-side converter through a wireless transmitter through resonance. After the secondary-side converter receives the energy, it outputs the energy to the load in a DC output mode. In addition, users can It is required to provide energy to the load end in AC mode through a sinusoidal pulse width modulator. In this way, the purpose of switching between AC and DC output modes is achieved.

According to one embodiment, the present invention provides a wireless energy conversion system, which includes a primary-side LLC converter, a wireless transmitter, and a secondary-side converter. The primary-side LLC converter includes a first rectifier circuit and an LLC resonance circuit coupled with the first rectifier circuit. The wireless transmitter is coupled to the LLC resonant circuit of the primary-side LLC converter. The secondary converter is coupled to the wireless transmitter. The primary-side LLC converter rectifies the DC input source through the first rectifier circuit to generate a first AC output, and triggers the LLC resonant circuit to provide an energy; the secondary-side converter receives energy through the wireless transmitter and generates a first AC output. An AC output is converted to produce a DC output.

Thereby, the wireless energy conversion system of the present invention utilizes the interaction of the primary-side LLC converter, the wireless transmitter, the secondary-side converter, and the sinusoidal pulse width modulator to realize the switching of AC and DC output modes and application requirements.

In the wireless energy conversion system of the above embodiment, the first rectifier circuit includes four power switches, and the four power switches are controlled to be turned on or off in a two-to-two pair, so as to perform pulse width modulation on an input signal.

In the wireless energy conversion system of the above embodiment, the secondary-side converter includes four rectifier diodes, and the four rectifier diodes are connected in pairs.

In the wireless energy conversion system of the above embodiment, the wireless transmitter includes two coils, one of which is coupled to the LLC resonant circuit of the primary-side LLC converter, and the other coil is coupled to the secondary-side converter, and is coupled to each other through the two coils Induction and transfer of energy from the primary side LLC converter to the secondary side converter.

The wireless energy conversion system of the above embodiment further includes a sinusoidal pulse width modulator, which is coupled to the secondary side converter. The sine pulse width modulator is used to convert the DC output generated by the secondary side converter into a second AC output.

In the wireless energy conversion system of the above embodiment, the sinusoidal pulse width modulator includes four unipolar switches, of which two unipolar switches are controlled to form pulse width modulation, and the remaining two unipolar switches are controlled to form sinusoidal pulse width modulation.

In the wireless energy conversion system of the above embodiment, when pulse width modulation is formed, a low frequency signal is generated; when sinusoidal pulse width modulation is formed, a high frequency signal is generated.

In the wireless energy conversion system of the above embodiment, the sine pulse width modulator generates two pulse width modulation signals to control two of the unipolar switches, and generates a two sinusoidal pulse width modulation signal to control the other two unipolar switches, and two sine pulse widths The frequency of the modulation signal is greater than the frequency of the two-pulse width modulation signal.

In the wireless energy conversion system of the above embodiment, the sine pulse width modulator further includes a triangle wave generating circuit, a sine wave generating circuit, a comparison circuit, an inverter circuit, and at least one dead zone adjustment circuit coupled to each other. After the triangle wave signal generated by the triangle wave generating circuit and the sine wave signal generated by the sine wave generating circuit are sent to the comparison circuit, a sine pulse width modulation basic signal is generated, and through the inverter circuit and at least one dead zone adjustment circuit, the high frequency and the The two sine wave is a sine pulse width modulation signal.

In the wireless energy conversion system of the above-mentioned embodiment, the number of at least one dead zone adjustment circuit is two, and the basic signal of the sinusoidal pulse width modulation is subjected to an inverted circuit One of the sine pulse width modulation signals is generated by the circuit and one of the dead zone adjustment circuits, and the sine pulse width modulation basic signal passes through another dead zone adjustment circuit to generate another sine pulse width modulation signal.

110: Primary side LLC converter

111: The first rectifier circuit

112: LLC resonant circuit

120: wireless transmitter

130: Secondary side converter

140: Sine Pulse Width Modulator

141: Triangular wave generating circuit

142: Sine wave generating circuit

143: comparison circuit

144: Inverting circuit

145: Dead zone adjustment circuit

4023, 4050, NE555: integrated circuit

A, B: Node

C, C _coss1 , C _coss2 , C _coss3 , C _coss4 , C ₃ : capacitance

C ₁ , C ₂ : filter capacitor

C _r : resonant capacitance

D, D ₁ , D ₂ , D ₃ , D ₄ : Diode

D ₅ , D ₆ , D ₇ , D ₈ : rectifier diode

GND: ground wire

I: The first mode of operation

II: The second mode of operation

III: The third mode of operation

ICL8038: signal generator

i _ds1 ,i _ds2 ,i _ds3 ,i _ds4 ,i _d1 ,i _d2 ,i _Lm ,i _Lr ,i _d5 ,i _d6 ,i _d7 ,i _d8 : current

i _p : wireless transmitter current

L: Inductance

L _r : first resonant inductance

L _m : second resonant inductance

LOAD: load side

PWM ₁ : Pulse width modulation signal

PWM ₂ : Pulse width modulation signal

PWM ₃ : Pulse width modulation signal

PWM ₄ : Pulse width modulation signal

Q1, Q2, Q3, Q4: power switch

Q5, Q6, Q7, Q8: single pole switch

R: resistance

SPWM_wave: Basic signal of sine pulse width modulation

SPWM ₁ : Sine pulse width modulation signal

SPWM ₂ : Sine pulse width modulation signal

t,t ₀ ,t ₁ ,t ₂ ,t ₃ : time

V: power supply voltage

V _AB ,V _ds1 ,V _ds2 ,V _ds3 ,V _ds4 : voltage

V _DC : DC output

V _out : second AC output

VR: Variable resistance

V _s : DC input source

Figure 1 is a schematic diagram showing the system architecture of a wireless energy conversion system according to an embodiment of the present invention;

Fig. 2 is a schematic diagram showing the circuit structure of the wireless energy conversion system of the embodiment in Fig. 1;

Fig. 3 is a schematic diagram showing the first operation mode of the wireless energy conversion system of the embodiment in Fig. 1;

Fig. 4 is a schematic diagram showing the second operation mode of the wireless energy conversion system of the embodiment in Fig. 1;

Fig. 5 is a schematic diagram showing the third operation mode of the wireless energy conversion system of the embodiment in Fig. 1;

Fig. 6 is a schematic diagram showing the circuit structure of the sinusoidal pulse width modulator of the wireless energy conversion system of the embodiment in Fig. 1;

Fig. 7 is a schematic diagram showing the operation waveforms of the components of the wireless energy conversion system of the embodiment in Fig. 1;

Fig. 8 is a schematic diagram showing the operation waveforms of the components of the wireless energy conversion system following the embodiment in Fig. 7;

Fig. 9 is a schematic diagram showing the signal generation circuit structure of the sinusoidal pulse width modulator of the wireless energy conversion system of the embodiment in Fig. 1;

FIG. 10 is a schematic diagram showing the circuit structure of the triangle wave generating circuit, the sine wave generating circuit, and the comparison circuit of the embodiment in FIG. 9;

FIG. 11 is a schematic diagram showing the circuit structure of the inverter circuit and the dead zone adjusting circuit of the embodiment in FIG. 9;

FIG. 12 is a schematic diagram of the circuit structure of the signal generator of the pulse width modulation signal of the sinusoidal pulse width modulator of the embodiment in FIG. 6; and

FIG. 13 is a comparison diagram of the conversion efficiency of the DC output and the second AC output of the wireless energy conversion system of the present invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. For the sake of clarity, many practical details will be explained in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is to say, in some embodiments of the present invention, these practical details are unnecessary. In addition, for the sake of simplifying the drawings, some conventionally used structures and elements will be drawn in a simple schematic manner in the drawings; and repeated elements may be represented by the same numbers.

In addition, when an element (or unit or module, etc.) is "coupled" to another element in this document, it can mean that the element is directly coupled to another element, or that a certain element is indirectly coupled to another element. Another element means that there is another element between the element and another element. When it is clearly stated that a certain element is "directly coupled" to another element, it means that there is no other element between the element and another element. The terms first, second, and third are only used to describe different elements, and there are no restrictions on the elements themselves. Therefore, the first element It can also be renamed as the second element. Moreover, the combination of elements/units/circuits in this article is not a combination of general, conventional, or conventional in this field. Whether the elements/units/circuits themselves are conventional or not can not be used to determine whether the combination relationship is easy to be used in the technical field. Usually the knowledgeable person can do it easily.

Please refer to Figure 1 and Figure 2 together. FIG. 1 is a schematic diagram of the system architecture of the wireless energy conversion system according to an embodiment of the present invention; FIG. 2 is a schematic diagram of the circuit architecture of the wireless energy conversion system of the embodiment in FIG. 1.

The wireless energy conversion system includes a primary-side LLC converter 110, a wireless transmitter 120, a secondary-side converter 130, and a sinusoidal pulse width modulator 140. The primary-side LLC converter 110 includes a first rectifier circuit 111 and an LLC resonance circuit 112 coupled to the first rectifier circuit 111. The wireless transmitter 120 is coupled to the LLC resonant circuit 112 of the primary-side LLC converter 110. The secondary converter 130 is coupled to the wireless transmitter 120. The sinusoidal pulse width modulator 140 is coupled to the secondary side converter 130.

The first rectifier circuit 111 includes four power switches Q1, Q2, Q3, and Q4. The four power switches Q1, Q2, Q3, and Q4 are controlled and turned on or off in two-to-two pairs respectively to perform pulse width modulation on an input signal. The power switches Q1 and Q4 are controlled by the pulse width modulation signal PWM ₁ , And the power switches Q2 and Q3 are controlled by the pulse width modulation signal PWM ₂ . In addition, the first rectifier circuit 111 includes capacitors C _coss1 , C _coss2 , C _coss3 , C _coss4 , filter capacitor C ₁ , diodes D ₁ , D ₂ , D ₃ , D ₄ and currents i _ds1 , i _ds2 , i _d1 , I _d2 . In addition, the first rectifier circuit 111 further includes currents i _ds3 and i _ds4 , as shown in FIG. 7. In addition, the LLC resonance circuit 112 includes a resonance capacitor C _r , a first resonance inductance L _r and a second resonance inductance L _m . The first resonant inductor L _{r is} coupled between the resonant capacitor C _r and the second resonant inductor L _m .

The wireless transmitter 120 includes two coils. One of the coils is coupled to the LLC resonant circuit 112 of the primary-side LLC converter 110, and the other coil is coupled to the secondary-side converter 130. The two coils can be coupled to each other to induce energy to transmit energy from the primary-side LLC converter 110 to the secondary-side converter 130.

The secondary converter 130 includes four rectifier diodes D5, D6, D7, D8 and currents i _d5 , i _d6 , i _d7 , and i _d8 , as shown in FIG. 7. Four rectifier diodes D5, D6, D7, and D8 are connected in two to form a bridge rectifier.

In Figure 1, when the DC load is used, the sine pulse width modulator 140 is not passed through, and the DC output can be directly generated by the secondary side converter 130. When under AC load, the second AC output V _{out is} generated through the sinusoidal pulse width modulator 140.

In other words, the primary-side LLC converter 110 can rectify the DC input source V _s through the first rectifier circuit 111 to generate a first AC output, and trigger the LLC resonant circuit 112 to provide an energy. The secondary converter 130 receives energy through the wireless transmitter 120 and converts the first AC output to generate a DC output. At this time, the output is a DC signal corresponding to a DC load. When the sine pulse width modulator 140 is used, the DC output generated by the secondary side converter 130 can be converted into a second AC output V _out . At this time, the output is an AC signal corresponding to an AC load, as shown in FIG. 2.

The operation mode of the wireless energy conversion system of the present invention is described below. Fig. 3 is a schematic diagram of the first operation mode of the wireless energy conversion system of the embodiment in Fig. 1; Fig. 4 is a schematic diagram of the second operation mode of the wireless energy conversion system of the embodiment in Fig. 1; Fig. 5 is A schematic diagram of the third operation mode of the wireless energy conversion system of the embodiment in FIG. 1 is shown. First, it will be explained that the sine pulse width modulator 140 is not used in the first operation mode, the second operation mode, and the third operation mode. The operation mode of the sine pulse width modulator 140 will be described in subsequent embodiments. At the same time, please also refer to the operating waveform diagrams of the components of the wireless energy conversion system shown in Figures 7 and 8.

The first operation mode I (t ₀ <t<t ₁ ): The power switches Q ₁ and Q _{4 are} turned off, and Q ₂ and Q _{3 are} turned on. This is the stage before the dead time when the switches are turned off at the same time. At this time, the rectifier diodes D ₆ and D _{7 of the} secondary-side converter 130 are in a conducting state to perform a rectification operation, and the power switches Q ₂ and Q ₃ are in a conducting state to form a loop. As time _{moves toward t 1} , the current i _ds2 gradually decreases until the power switch Q _{2 is} turned off. The wireless transmitter current i _p gradually decreases to 0 in this interval, and the current i _Lm is equal to the current i _Lr at this time.

The second operation mode II (t ₁ <t<t ₂ ): the power switches Q ₁ , Q ₂ , Q ₃ , and Q ₄ are all in the off state, that is, the dead time, and the rectifier diode of the secondary side converter 130 _{D 5, D 6, D 7} , D 8 is in this range D _5, D ₈ is turned, D _6, D ₇ is turned off. In this interval, the wireless transmitter current i _p has completed commutation in the previous interval, so the resonant current provides freewheeling energy for the wireless transmitter 120 in this interval, and the primary-side LLC converter 110 passes through the wireless transmitter 120 The energy transferred to the secondary side converter 130 turns on the rectifier diodes D ₅ and D ₈ and discharges the load terminal LOAD. At this time, the _{same voltage source such as the filter capacitor C 2} also discharges the load terminal LOAD. The power switches Q ₁ and Q ₄ provide a discharge path. At this time, the voltages V _ds1 and V _{ds4 are} reduced to 0, forming a zero voltage switching (ZVS), so switching without energy loss can be achieved. The voltages V _ds2 and V _ds3 rise.

The third operation mode III (t ₂ <t<t ₃ ): The power switches Q ₁ and Q _{4 are} turned on, and the voltage at both ends of the wireless transmitter 120 is clamped to nV _o (n: the ratio of coil turns) by the output voltage, so the current i _Lm continues to rise until t=t ₃ , and at this time, the current i _ds1 gradually rises, the resonant capacitor C _r and the first resonant inductor L _r resonate, and the wireless transmitter current i _p also gradually rises in this interval, reducing the energy from one time The side LLC converter 110 continuously transmits to the secondary side converter 130. _{The rectifier diodes D 5} and D _{8 of the} secondary-side converter 130 continue to conduct. At this time, the secondary-side current _{stores energy in the filter capacitor C 2} and transfers the energy to the load terminal LOAD until t=t ₃ , the excitation The inductance will reach the maximum, and the wireless transmitter current i _p will gradually decrease to zero. When the current directions in the first operation mode, the second operation mode, and the third operation mode described above are reverse operation, the operation principle is the same as the above steps, but the phase is opposite.

Please refer to Figure 6. FIG. 6 is a schematic diagram of the circuit structure of the sinusoidal pulse width modulator 140 of the wireless energy conversion system of the embodiment in FIG. 1. FIG. The sinusoidal pulse width modulator 140 includes four unipolar switches Q5, Q6, Q7, Q8, an inductor L, a capacitor C _3, and nodes A and B. The voltage difference between nodes A and B is the voltage V _AB and two unipolar switches Q7 , Q8 is controlled to form pulse width modulation, that is, the unipolar switches Q7 and Q8 are respectively controlled by the pulse width modulation signals PWM ₃ and PWM ₄ to form pulse width modulation, and the other two unipolar switches Q5 and Q6 are controlled to form Sinusoidal pulse width modulation, that is, the unipolar switches Q5 and Q6 are respectively controlled by the sinusoidal pulse width modulation signals SPWM ₁ and SPWM ₂ to form a sinusoidal pulse width modulation.

For more details, please refer to Figure 9. Fig. 9 is a schematic diagram showing the signal generation circuit structure of the sinusoidal pulse width modulator 140 of the wireless energy conversion system of the embodiment in Fig. 1. Please also refer to the circuit of the sinusoidal pulse width modulator 140 in the embodiment of Fig. 6 Architecture. The sinusoidal pulse width modulator 140 is switched through the unipolar switches Q5, Q6, Q7, and Q8 to switch the DC output V _{DC in} Figure 6 to an AC voltage. At the same time, the sine pulse width modulator 140 further includes a triangle wave generating circuit 141, a sine wave generating circuit 142, a comparison circuit 143, an inverter circuit 144, and at least one dead zone adjustment circuit 145 coupled to each other. In operation, the triangle wave signal generated by the triangle wave generating circuit 141 and the sine wave signal generated by the sine wave generating circuit 142 are first sent to the comparison circuit 143 to generate the sine pulse width modulation basic signal SPWM_wave, and pass through the inverter circuit 144 and the dead zone The adjustment circuit 145 generates two sine pulse width modulation signals SPWM ₁ and SPWM ₂ , which are high-frequency and sine waves; specifically, the frequency of the sine pulse width modulation signals SPWM ₁ and SPWM ₂ can be 20 kHz, but not limit. The two sinusoidal pulse width modulation signals SPWM ₁ and SPWM ₂ respectively control the unipolar switches Q5 and Q6 in the sinusoidal pulse width modulator 140. The original low-frequency and square-wave pulse width modulation signals PWM ₃ and PWM ₄ respectively control the unipolar switches Q7 and Q8; specifically, _{the frequency of the pulse width modulation signals PWM 3} and PWM ₄ can be 60 Hz, but not Limited by this. The following Figs. 10 to 12 will illustrate the details of a possible embodiment of the sinusoidal pulse width modulator 140 in Fig. 9, but the present invention is not limited thereto.

Please refer to FIG. 10. FIG. 10 is a schematic diagram illustrating the circuit structure of the triangle wave generating circuit 141, the sine wave generating circuit 142, and the comparing circuit 143 of the embodiment in FIG. 9. The triangle wave generating circuit 141 includes a signal generator ICL8038, five resistors R, three variable resistors VR, a capacitor C, a power supply voltage V, and a ground line GND. The signal generator ICL8038 is connected to the resistor R and the variable resistor VR. The connection and operation of the capacitor C and the third pin (Pin3) generate a triangular wave signal. The signal generator ICL8038 is a conventional circuit, and its details will not be repeated. Furthermore, the sine wave generating circuit 142 includes a signal generator ICL8038, five resistors R, three variable resistors VR, a capacitor C, a power supply voltage V and a ground line GND, and the signal generator ICL8038 is connected to the resistor R, The connection and operation of the variable resistor VR and the capacitor C generate a sine wave signal on the second pin (Pin2). In addition, the comparison circuit 143 includes an operational amplifier (Operational Amplifier; OPA). The operational amplifier receives the triangle wave signal and the sine wave signal and performs operations to generate a sine pulse width modulation basic signal SPWM_wave.

Please refer to FIG. 11. FIG. 11 is a schematic diagram of the circuit structure of the inverter circuit 144 and the dead zone adjusting circuit 145 of the embodiment in FIG. 9. The inverter circuit 144 includes an integrated circuit 4023 (IC 4023), and its sixth pin (Pin6) and tenth pin (Pin10) can respectively generate two inverted signals. In addition, the number of dead zone adjustment circuits 145 is two. Each dead zone adjustment circuit 145 includes a diode D, a variable resistor VR, and a capacitor C, and the diode D, the variable resistor VR, and the capacitor C mutually interact with each other. connection. The two dead zone adjustment circuits 145 receive signals from the 6th pin (Pin6) and the 10th pin (Pin10) of the integrated circuit 4023 respectively, and respectively generate sinusoidal pulse width modulation signals through the integrated circuit 4050 (IC 4050) SPWM ₁ , SPWM ₂ . As for the integrated circuit 4050, it includes a plurality of buffer gates, which can be used to buffer signals. The integrated circuit 4023 and the integrated circuit 4050 are both conventional circuits, and the details thereof will not be repeated.

Please refer to FIG. 12, where FIG. 12 is a schematic diagram of the circuit structure of the signal generator _{of the pulse width modulation signals PWM 3} and PWM _{4 of the sinusoidal pulse width modulator 140 in the embodiment in FIG. 6.} This signal generator consists of an integrated circuit NE555 (IC NE555), three resistors R and two capacitors C. The third pin (Pin3) of the integrated circuit NE555 can generate pulse width modulation signals PWM ₃ and PWM ₄ , thereby Control the unipolar switches Q7 and Q8 of the sine pulse width modulator 140. The integrated circuit NE555 is a conventional circuit, and its details will not be repeated.

Please continue to refer to FIG. 13, which is a comparison diagram of the conversion efficiency of the DC output and the second AC output of the wireless energy conversion system of the present invention. From Figure 10, corresponding to various load conditions, the conversion efficiency of both the DC output and the second AC output can reach an average of 86% or more, and the highest efficiency can reach 89.3%, which can explain the wireless energy conversion system of the present invention. It can achieve wireless energy transmission output, and has high conversion efficiency, which can be applied to high-power loads.

Therefore, the present invention discloses a wireless energy transmission conversion system that can provide an output of 1kW. The primary-side LLC converter 110 uses a full-bridge first rectifier circuit 111 combined with the LLC resonant circuit 112, and transmits energy through the coil coupling of the wireless transmitter 120 to the secondary-side converter 130 through resonance. After the secondary-side converter 130 receives energy through the coil of the wireless transmitter 120, it transfers the energy to direct current _{through the rectifier diodes D 5} , D ₆ , D ₇ , and D _{8 of the secondary-side converter 130} The output mode is provided to the load terminal LOAD. In addition, the user can provide energy to the load terminal LOAD in an AC output mode through the control method of the sinusoidal pulse width modulator 140 according to the demand of the output type. This can achieve the purpose of optional switching between AC output or DC output. In addition, the present invention utilizes LLC resonance technology to enable the primary-side LLC converter 110 and the secondary-side converter 130 to have a zero-voltage switching function, thereby improving the switching loss and improving the overall efficiency of the circuit.

The present invention uses coil type wireless energy transmission combined with LLC resonance to improve the overall circuit efficiency. Conventional converter architectures are mostly LC series resonance mode. The present invention uses LLC series parallel resonance mode to replace the LC series resonance mode, which can improve the conversion efficiency.

The features of the present invention are as follows: (1) The wireless transmitter uses the equivalent model of a loosely coupled transformer to construct a coil that integrates leakage inductance and magnetizing inductance to achieve the function of wireless energy transmission. (2) Using LLC resonance technology to make the power switch have the advantage of zero-voltage switching to improve the conversion efficiency. (3) The output can be set to DC output or AC output according to load characteristics.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone who is familiar with the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be subject to the scope of the attached patent application.

110: Primary side LLC converter

120: wireless transmitter

130: Secondary side converter

140: Sine Pulse Width Modulator

V _s : DC input source

Claims (8)

A wireless energy conversion system includes: a primary-side LLC converter including a first rectifier circuit and an LLC resonance circuit coupled to the first rectifier circuit; and a wireless transmitter coupled to the LLC Resonant circuit; a secondary side converter coupled to the wireless transmitter; and a sinusoidal pulse width modulator coupled to the secondary side converter; wherein the primary side LLC converter passes through the first The rectifier circuit rectifies the DC input source to generate a first AC output, and triggers the LLC resonant circuit to provide an energy; the secondary side converter receives the energy through the wireless transmitter and performs the first AC output The sine pulse width modulator is used to convert the dc output generated by the secondary side converter into a second ac output. The sine pulse width modulator includes four unipolar switches, two of which are The unipolar switch is controlled to form a pulse width modulation, and the other two unipolar switches are controlled to form a sinusoidal pulse width modulation. The wireless energy conversion system according to claim 1, wherein the first rectifier circuit includes four power switches, and the four power switches are controlled to be turned on or off in a two-to-two paired manner to perform pulse width modulation on an input signal . The wireless energy conversion system according to claim 1, wherein the secondary-side converter includes four rectifier diodes, and the four rectifier diodes are connected in pairs. The wireless energy conversion system according to claim 1, wherein the wireless transmitter includes two coils, one of the coils is coupled to the LLC resonant circuit of the primary-side LLC converter, and the other coil is coupled to the secondary The side converter transmits the energy from the primary side LLC converter to the secondary side converter through mutual coupling and induction of the two coils. The wireless energy conversion system according to claim 1, wherein when pulse width modulation is formed, a low frequency signal is generated; when sine pulse width modulation is formed, a high frequency signal is generated. The wireless energy conversion system according to claim 1, wherein the sine pulse width modulator generates two pulse width modulation signals to control the two unipolar switches, and generates two sine pulse width modulation signals to control the remaining two unipolar switches , And the frequency of the two-sine pulse width modulation signal is greater than the frequency of the two pulse width modulation signal. The wireless energy conversion system according to claim 1, wherein the sine pulse width modulator further includes a triangle wave generating circuit, a sine wave generating circuit, a comparison circuit, an inverter circuit, and at least one dead zone adjustment circuit coupled to each other , The triangle wave generating circuit generates a triangle wave signal and the sine wave generating circuit generates a sine wave signal that is sent to the comparison circuit for comparison, and a sine pulse width modulation basic signal is generated, and is communicated with the at least A dead zone adjustment circuit generates two sine pulse width modulation signals with high frequency and sine waves. The wireless energy conversion system according to claim 7, wherein the number of the at least one dead zone adjustment circuit is two, and the sine pulse width modulation basic signal passes through the inverter circuit and one of the dead zone adjustment circuits to generate one of the sine waves A pulse width modulation signal. The sine pulse width modulation basic signal passes through another dead zone adjustment circuit to generate another sine pulse width modulation signal.

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