Electronic device and method for estimating input power input to resonant tank in resonant circuit

Abstract

An electronic device is used for calculating input power input to a resonant tank in a resonant circuit. The electronic device comprises a band-pass filter, a phase detection circuit, a peak detection circuit and a processor. The band-pass filter receives the resonant current input to the resonant tank and filters the resonant current to generate a first fundamental frequency current. The phase detection circuit calculates a phase difference between the first fundamental frequency current and the resonant tank voltage. The peak detection circuit generates a fundamental current peak according to the first fundamental current. The processor performs fast Fourier transform on the resonant tank voltage to obtain a resonant tank fundamental frequency voltage. The processor calculates the input power according to the resonant tank fundamental frequency voltage, the fundamental frequency current peak value and the phase difference. The disclosure also relates to a method of estimating an input power input to a resonant tank in a resonant circuit.

Description

Technical Field

[0001] This invention relates to electronic devices, and more particularly to electronic devices and methods for estimating the input power to a resonant slot in a resonant circuit. Background Technology

[0002] Traditional power estimation techniques utilize high-speed sampling of the voltage and current signals input to the resonant tank. The voltage and current signals are multiplied, integrated, and averaged to obtain the input power. This estimation process is computationally complex and requires a high-order microprocessor for execution. Summary of the Invention

[0003] An electronic device according to an embodiment of the present invention for calculating the input power input to a resonant slot in a resonant circuit includes a bandpass filter, a phase detection circuit, a peak detection circuit, and a processor. The bandpass filter receives the resonant current input to the resonant slot and filters the resonant current to generate a first fundamental frequency current. The phase detection circuit is electrically connected to the bandpass filter and calculates the phase difference between the rising edges of the first fundamental frequency current and the resonant slot voltage. The peak detection circuit is electrically connected to the bandpass filter and calculates the first fundamental frequency current to generate a peak value of the fundamental frequency current. The processor is electrically connected to the phase detection circuit and the peak detection circuit and performs a fast Fourier transform on the resonant slot voltage to obtain the resonant slot fundamental frequency voltage. The processor calculates the input power based on the resonant slot fundamental frequency voltage, the peak value of the fundamental frequency current, and the phase difference.

[0004] In the electronic device described above, the processor calculates the input power using the following formula: P r For input power, V rp1 I is the fundamental frequency voltage of the resonant slot. rp,PDC For the peak value of the fundamental frequency current, and θ v1 -θ i1 This is the phase difference between the rising edges of the first fundamental frequency current and the resonant slot voltage.

[0005] The electronic device described above also includes a subtractor. The subtractor is electrically connected to the processor, receives a reference input power and an input power from the processor, and subtracts the reference input power from the input power to obtain the power difference.

[0006] The electronic device described above also includes a power regulator. The power regulator is electrically connected to a subtractor and adjusts the input power based on the power difference to obtain the total input power.

[0007] The electronic device described above also includes a pulse frequency modulation circuit. The pulse frequency modulation circuit is electrically connected to the power regulator, adjusts the frequency of the pulse signal according to the total input power, and outputs the pulse signal.

[0008] The electronic device described above also includes a gate driving circuit. The gate driving circuit is electrically connected to the pulse frequency modulation circuit and drives the resonant circuit according to the pulse signal.

[0009] As in the electronic devices described above, the resonant circuit is an inductor-inductor-capacitor (LLC) circuit, or a resonant circuit used for wireless power transmission, or a resonant circuit for an induction cooker.

[0010] A method for estimating the input power of a resonant slot in a resonant circuit according to an embodiment of the present invention includes: receiving a resonant current input to the resonant slot and filtering the resonant current to generate a first fundamental frequency current; calculating the phase difference between the rising edges of the first fundamental frequency current and the resonant slot voltage; calculating the first fundamental frequency current to generate a fundamental frequency current peak; performing a fast Fourier transform on the resonant slot voltage to obtain the resonant slot fundamental frequency voltage; and calculating the input power based on the resonant slot fundamental frequency voltage, the fundamental frequency current peak, and the phase difference.

[0011] As described above, the step of calculating the input power based on the fundamental frequency voltage, the peak value of the fundamental frequency current, and the phase difference of the resonant tank includes: calculating the input power using a formula; wherein the formula is: P r For input power, V rp1 I is the fundamental frequency voltage of the resonant slot. rp,PDC For the peak value of the fundamental frequency current, and θ v1 -θ i1 This is the phase difference between the rising edges of the first fundamental frequency current and the resonant slot voltage.

[0012] The method described above further includes: receiving a reference input power and subtracting the reference input power from the input power to obtain a power difference; adjusting the input power based on the power difference to obtain a total input power; adjusting the frequency of the pulse signal based on the total input power and outputting the pulse signal; and driving the resonant circuit based on the pulse signal. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of an electronic device 100 according to an embodiment of the present invention.

[0014] Figure 2 Embodiments of the present invention Figure 1 The input voltage V in the resonant circuit 102 in (t), resonant tank voltage V rp (t), and the resonant current i rp Waveform of (t).

[0015] Figure 3A Embodiments of the present invention Figure 1 The resonant slot voltage V in resonant circuit 102 rp Based on switching frequency f sThe spectrum diagram.

[0016] Figure 3B Embodiments of the present invention Figure 1 The resonant slot voltage V in resonant circuit 102 rp Based on mains frequency f ac The spectrum diagram.

[0017] Figure 3C Embodiments of the present invention Figure 1 The resonant slot voltage V in resonant circuit 102 rp Based on switching frequency f s and sideband frequency f s ±kf ac The spectrum diagram.

[0018] Figure 4A Embodiments of the present invention Figure 1 The resonant current i in resonant circuit 102 rp Based on switching frequency f s The spectrum diagram.

[0019] Figure 4B Embodiments of the present invention Figure 1 The resonant current i in resonant circuit 102 rp Based on mains frequency f ac The spectrum diagram.

[0020] Figure 4C Embodiments of the present invention Figure 1 The resonant current i in resonant circuit 102 rp Based on switching frequency f s and sideband frequency f s ±kf ac The spectrum diagram.

[0021] Figure 5 Embodiments of the present invention Figure 1 The resonant slot impedance |Z in resonant circuit 102 pn | and switching frequency f s The relationship between the frequency and its harmonic frequency.

[0022] Figure 6 Embodiments of the present invention Figure 1 The first fundamental frequency current i in the resonant circuit 102 rp,BPF (t), low-frequency current i rp,PDC (t) and the peak value of the fundamental frequency current I rp,PDC The waveform diagram.

[0023] Figure 7 Embodiments of the present invention Figure 1 The resonant slot voltage v in resonant circuit 102 rp , fundamental frequency voltage V rp,BPFand the first fundamental frequency current i rp,BPF The waveform diagram.

[0024] Figure 8A The input power P calculated by the processor 114 in this embodiment of the invention r Based on switching frequency f s The spectrum diagram.

[0025] Figure 8B The input power P calculated by the processor 114 in this embodiment of the invention r Based on switching frequency f s and sideband frequency f s ±kf ac The spectrum diagram.

[0026] Figure 9A Embodiments of the present invention Figure 1 A schematic diagram of the resonant circuit 102.

[0027] Figure 9B Embodiments of the present invention Figure 1 A schematic diagram of the resonant circuit 102.

[0028] Figure 10 This is a flowchart illustrating a method for estimating the input power to the resonant slot in a resonant circuit, according to an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100: Electronic devices

[0031] 102: Resonant Circuit

[0032] 104: Power Control Area Circuit

[0033] 106: Gate drive circuit

[0034] 108: Bandpass filter

[0035] 110: Phase detection circuit

[0036] 112: Peak detection circuit

[0037] 114: Processor

[0038] 116: Subtractor

[0039] 118: Power Regulator

[0040] 120: Pulse frequency modulation circuit

[0041] i rp Resonant current

[0042] V rp : Resonant slot voltage

[0043] i in Input current

[0044] V in Input voltage

[0045] i rp,BPF First fundamental frequency current

[0046] I rp,PDC : Peak value of fundamental frequency current

[0047] θ v1-i1 Phase difference

[0048] P r Input power

[0049] Reference input power

[0050] G h G l Pulse signal

[0051] G oh G ol Drive signal

[0052] V ac AC power supply

[0053] D1, D2, D3, D4: Diodes

[0054] C in C rp :capacitance

[0055] L rp :inductance

[0056] Q h Q l :transistor

[0057] R eq Load resistance

[0058] V in (t): Input voltage

[0059] V rp (t): Voltage of the resonant tank

[0060] i rp (t): Resonant current

[0061] T ac : Exchange cycle

[0062] D: Upper arm switch closing time during switching cycle T s The ratio T s Switching cycle time

[0063] f s Switching frequency

[0064] f ac Mains frequency

[0065] f s ±kf ac Sideband frequency

[0066] n: nth harmonic of the switching frequency

[0067] k: k-th harmonic of the mains frequency

[0068] V rp,BPF : Fundamental frequency voltage

[0069] T1: Transformer

[0070] L m ,L rs :inductance

[0071] C rs :capacitance

[0072] n: 1: The turns ratio of the primary and secondary sides of transformer T1

[0073] i o Output current

[0074] V o Output voltage

[0075] S1000, S1002, S1004, S1006, S1008: Steps Detailed Implementation

[0076] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same element references are used in the drawings and description to denote the same or similar parts.

[0077] Throughout this specification and the appended claims, certain terms are used to refer to specific elements. Those skilled in the art will understand that electronic system manufacturers may use different names to refer to the same components. This document is not intended to distinguish between components that function identically but have different names. In the following specification and claims, words such as "containing" and "comprising" are open-ended terms and should therefore be interpreted as "containing but not limited to...".

[0078] The directional terms used herein, such as "up," "down," "front," "back," "left," and "right," are for reference only to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting this disclosure. In the accompanying drawings, each figure illustrates general features of the methods, structures, and / or materials used in specific embodiments. However, these figures should not be construed as defining or limiting the scope or nature covered by these embodiments. For example, for clarity, the relative dimensions, thicknesses, and positions of various films, regions, and / or structures may be reduced or enlarged.

[0079] In this invention, a structure (or layer, component, substrate) located above / above another structure (or layer, element, substrate) can refer to the two structures being adjacent and directly connected, or to the two structures being adjacent but not directly connected. Indirect connection means that there is at least one intermediary structure (or intermediary layer, intermediary component, intermediary substrate, intermediary spacer) between the two structures, with the lower surface of one structure adjacent to or directly connected to the upper surface of the intermediary structure, and the upper surface of the other structure adjacent to or directly connected to the lower surface of the intermediary structure. The intermediary structure can be composed of a single-layer or multi-layer solid structure or a non-solid structure, without limitation. In this disclosure, when a structure is disposed "on" another structure, it may mean that the structure is "directly" on the other structure, or that the structure is "indirectly" on the other structure, that is, at least one structure is sandwiched between the structure and the other structure.

[0080] The terms “approximately,” “equal to,” “equivalent to,” “same,” “substantially,” or “proximately” are generally interpreted as being within 20% of a given value or range, or as being within 10%, 5%, 3%, 2%, 1%, or 0.5% of a given value or range.

[0081] The ordinal numbers used in the specification and claims, such as "first," "second," etc., to modify elements, do not in themselves imply or represent any prior ordinal number of that element (or those elements), nor do they represent the order of one element with another, or the order of manufacturing processes. The use of these ordinal numbers is solely to clearly distinguish one named element from another element with the same name. The claims and the specification may not use the same terminology; therefore, a first component in the specification may be a second component in the claims.

[0082] The electrical connection or coupling described in this invention can refer to a direct connection or an indirect connection. In the case of a direct connection, the endpoints of the two circuit components are directly connected or connected to each other by a conductor segment. In the case of an indirect connection, the endpoints of the two circuit components are connected by a switch, diode, capacitor, inductor, resistor, other suitable components, or a combination of the above components, but are not limited thereto.

[0083] In this invention, the thickness, length, and width can be measured using an optical microscope, while the thickness or width can be measured from a cross-sectional image in an electron microscope, but these are not limitations. Furthermore, any two values ​​or directions used for comparison may have a certain degree of error. Additionally, the terms "equal to," "equivalent to," "identical," "substantially," or "approximately" used in this invention generally mean falling within 10% of a given value or range. Moreover, the terms "given range is from a first value to a second value" and "given range falls within the range of the first value to the second value" indicate that the given range includes the first value, the second value, and other values ​​in between. If the first direction is perpendicular to the second direction, the angle between the first and second directions can be between 80 and 100 degrees; if the first direction is parallel to the second direction, the angle between the first and second directions can be between 0 and 10 degrees.

[0084] It should be understood that the following embodiments can be implemented by replacing, recombining, or mixing features from several different embodiments without departing from the concept of this disclosure to complete other embodiments. Features between embodiments can be arbitrarily mixed and combined as long as they do not violate the inventive concept or conflict with it.

[0085] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It is understood that these terms, for example, as defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the relevant art and the background or context of this disclosure, and should not be interpreted in an idealized or overly formal manner, unless specifically defined in embodiments of this disclosure.

[0086] Figure 1 This is a schematic diagram of an electronic device 100 according to an embodiment of the present invention. Figure 1 As shown, the electronic device 100 includes a resonant circuit 102, a power control region circuit 104, and a gate drive circuit 106. In some embodiments, the resonant circuit 102 may be, for example, a part of the circuit in an induction cooker, but the invention is not limited thereto. The power control region circuit 104 is used to calculate the input power P input to a resonant slot in the resonant circuit 102. r And based on the input power P r The pulse signal G used to drive the resonant circuit 102 h or pulse signal G lThe frequency is controlled by the gate drive circuit 106, which drives the resonant circuit 102. In some embodiments, the power control region circuit 104 includes a bandpass filter 108, a phase detection circuit 110, a peak detection circuit 112, a processor 114, a subtractor 116, a power regulator 118, and a pulse frequency modulation circuit 120.

[0087] The bandpass filter 108 receives a resonant current i input to the resonant slot in the resonant circuit 102. rp And for the resonant current i rp Filtering is performed to generate a first fundamental frequency current i. rp,BPF The phase detection circuit 110 is electrically connected to the bandpass filter 108 to calculate the first fundamental frequency current i. rp,BPF and a resonant tank voltage V rp A phase difference θ at the rising edge v1-i1 The peak detection circuit 112 is electrically connected to the bandpass filter 108 to calculate the first fundamental frequency current i. rp,BPF Generate a fundamental frequency current peak I rp,PDC The processor 114 is electrically connected to the phase detection circuit 110 and the peak detection circuit 112 to detect the resonant tank voltage V. rp Perform a fast Fourier transform to obtain the fundamental frequency voltage V of a resonant tank. rp1 Processor 114 operates based on the fundamental frequency voltage V of the resonant slot. rp1 , Peak fundamental frequency current I rp,PDC and phase difference θ v1-i1 Calculate the input power P r .

[0088] In detail, processor 114 calculates the input power P using the following formula 1. r .

[0089]

[0090] In equation 1, P r For input power, V rp1 I is the fundamental frequency voltage of the resonant slot. rp,PDC For the peak value of the fundamental frequency current, and θ v1 -θ i1 The first fundamental frequency current i rp,BPF and resonant slot voltage V rp The phase difference of the rising edge.

[0091] Subtractor 116 is electrically connected to processor 114 and receives a reference input power. and the input power P from processor 114 r And the reference input power and input power P rThe difference is obtained by subtracting the two values. The power regulator 118 is electrically connected to the subtractor 116 and adjusts the input power P based on the power difference. r This is used to obtain a total input power. In some embodiments, the reference input power is... This could be, for example, a target power set by the user, but the invention is not limited thereto. For example, when the input power P... r Less than the reference input power At that time, the power regulator 118 can correspondingly increase the input power P. r The power value is used to obtain the total input power. Furthermore, when the input power P... r Greater than the reference input power At that time, the power regulator 118 can correspondingly reduce the input power P. r The power value is used to obtain the total input power.

[0092] The pulse frequency modulation circuit 120 is electrically connected to the power regulator 118, adjusts the frequency of the pulse signal (e.g., a switching frequency) according to the total input power, and outputs the pulse signal. Figure 1 In this embodiment, the pulse signal may be, for example, a pulse signal G. h and pulse signal G l However, the present invention is not limited thereto. The gate drive circuit 106 is electrically connected to the pulse frequency modulation circuit 120, based on the pulse signal G. h and pulse signal G l The corresponding output drive signal G oh and drive signal G ol , used to drive the resonant circuit 102.

[0093] exist Figure 1 In one embodiment, the resonant circuit 102 includes an AC power supply V. ac Diodes D1, D2, D3, and D4; Capacitor C in transistor Q h transistor Q l Inductor L rp Capacitor C rp and load resistance R eq AC power supply V ac One end is electrically connected to the first terminal of diode D1 and the second terminal of diode D2. AC power supply V ac The other end is electrically connected to the first terminal of diode D3 and the second terminal of diode D4. The second terminal of diode D1 is electrically connected to the second terminal of diode D3. The first terminal of diode D2 is electrically connected to the first terminal of diode D4. Diodes D1, D2, D3, and D4 utilize the physical characteristic that signals can only pass from their first terminal to their second terminal, but not from their second terminal to their first terminal, to supply AC power V.ac The output signal is rectified to obtain the input current i. in and generated from capacitor C in Input voltage v at both ends in Capacitor C in The two ends are respectively connected across the second end of diode D3 and the first end of diode D4.

[0094] transistor Q h The control terminal receives the drive signal G from the gate drive circuit 106. oh Transistor Q h The first terminal is electrically connected to the second terminal of diode D3. Transistor Q h The second terminal is electrically connected to transistor Q. l The first terminal. Transistor Q. l The control terminal receives the drive signal G from the gate drive circuit 106. ol Transistor Q l The first terminal is electrically connected to the inductor L rp Transistor Q l The second terminal is electrically connected to the first terminal of diode D4 and capacitor C. rp The resonant slot of the resonant circuit 102 includes an inductor L. rp Capacitor C rp and load resistance R eq However, the present invention is not limited thereto. Transistor Q l The voltage across the first and second terminals is equal to the resonant slot voltage V. rp From transistor Q h The second end flows to inductor L rp The current is equal to the resonant current i rp .

[0095] Figure 2 Embodiments of the present invention Figure 1 The input voltage V in the resonant circuit 102 in (t), resonant tank voltage V rp (t), and the resonant current i rp The waveform of (t). Figure 2 As shown, in one AC period T ac In the process, due to rectification by diodes D1, D2, D3, and D4, the input voltage V in (t) A positive waveform with two peaks. In some embodiments, the AC period T ac AC power supply V ac frequency f ac The reciprocal of Q can be, for example, the reciprocal of the mains frequency of 60Hz. (Transistor Q) h and transistor Q l Drive signal Goh and drive signal G ol Frequency information is loaded into the input voltage V in In the waveform (t), the resonant slot voltage V is generated. rp The waveform of (t). In some embodiments, the resonant tank voltage V rp (t) can be expressed as the following formula 2 after being expanded into a Fourier series.

[0096]

[0097] In equation 2, Among them, V p AC power supply V ac The peak value of the sinusoidal voltage, D is the upper arm switch (e.g., transistor Q). h Closing time during switching cycle T s The proportion.

[0098] In equation 2, Among them, V p AC power supply V ac The peak value of the sinusoidal voltage, D is the upper arm switch (e.g., transistor Q). h Closing time during switching cycle T s The proportion, f ac AC power supply V ac The frequency.

[0099] In equation 2, Among them, V p AC power supply V ac The peak value of the sinusoidal voltage, n is the nth harmonic of the switching frequency (n is an odd number), and D is the upper arm switch (e.g., transistor Q). h Closing time during switching cycle T s The proportion, f s For a switch (e.g., transistor Q) h and transistor Q l The switching frequency of θ vn As shown in equation 7 below.

[0100] In equation 2, Among them, V p AC power supply V ac The peak value of the sinusoidal voltage, n is the nth harmonic of the switching frequency (n is an odd number), and D is the upper arm switch (e.g., transistor Q). h Closing time during switching cycle T s The proportion, f s For a switch (e.g., transistor Q) h and transistor Ql The switching frequency of f ac AC power supply V ac The frequency, θ vn As shown in equation 7 below.

[0101] In equations 5 and 6 Where n is the nth harmonic of the switching frequency (n is an odd number), and D is the upper arm switch (e.g., transistor Q). h Closing time during switching cycle T s The proportion.

[0102] As shown in equations 2 to 7 above, the resonant tank voltage V rp Including AC power supply V ac Mid-frequency f ac The signal components and their harmonic frequencies (k·f) ac The signal components, plus the high-frequency switching frequency f s The signal components and their harmonic frequencies (n·f) s ) and its sideband frequency (nf s ±kf ac (Signal components)

[0103] Similarly, in Figure 2 In the embodiment, the resonant current i rp (t) and resonant tank voltage V rp (t) are the same, and both carry the period DT s The information. Where D is the upper arm switch (e.g., transistor Q). h Closing time during switching cycle T s The proportion.

[0104] Figure 3A Embodiments of the present invention Figure 1 The resonant slot voltage V in resonant circuit 102 rp Based on switching frequency f s The spectrum diagram. For example... Figure 3A As shown, the resonant tank voltage V rp At switching frequency f s The maximum amplitude is at its resonant frequency (n=1), the second maximum amplitude is at frequency 0 (i.e., DC), and the maximum amplitude is at 3 times the switching frequency 3f. s There is a minor amplitude at (n=3), and at 5 times the switching frequency 5f s The minimum amplitude is at (n=5).

[0105] Figure 3B Embodiments of the present invention Figure 1 The resonant slot voltage V in resonant circuit 102 rp Based on mains frequency f ac The spectrum diagram. For example... Figure 3B As shown, the resonant tank voltage V rp It has its maximum amplitude at frequency 0 (i.e., DC), and at AC power supply V ac 2 times the frequency 2f ac There is a second large amplitude at 4 times the frequency 4f. ac There is a third large amplitude at 6 times the frequency (6f). ac There is a slightly smaller amplitude at this point, and at 8 times the frequency 8f. ac There is a minimum amplitude at that point.

[0106] Figure 3C Embodiments of the present invention Figure 1 The resonant slot voltage V in resonant circuit 102 rp Based on switching frequency f s and sideband frequency f s ±kf ac The spectrum diagram. For example... Figure 3C As shown, the resonant tank voltage V rp At switching frequency f s The maximum amplitude is at (n=1), and at the frequency (n·f) s +k·f ac ) and frequency (n·f s -k·f ac They have the same amplitude at point ).

[0107] Figure 4A Embodiments of the present invention Figure 1 The resonant current i in resonant circuit 102 rp Based on switching frequency f s The spectrum diagram. For example... Figure 4A As shown, due to capacitor C rp It will block the resonant current i rp The DC component in the resonant current i rp The amplitude is 0 at frequency 0 (i.e., DC). The resonant current i rp At switching frequency f s The maximum amplitude is at (n=1), and it occurs at 3 times the switching frequency 3f. s The minimum amplitude is at (n=3).

[0108] Figure 4B Embodiments of the present invention Figure 1 The resonant current i in resonant circuit 102 rp Based on mains frequency f ac The spectrum diagram. For example... Figure 4B As shown, due to capacitor C rp It will block the resonant current i rp The DC and low-frequency components in the resonant current i rp At frequency 0 (i.e., DC), AC power supply Vac 2 times the frequency 2f ac AC power supply V ac 4 times the frequency 4f ac AC power supply V ac 6 times the frequency 6f ac At the location, and AC power supply V ac 8 times the frequency 8f ac The amplitude at each location is 0.

[0109] Figure 4C Embodiments of the present invention Figure 1 The resonant current i in resonant circuit 102 rp Based on switching frequency f s and sideband frequency f s ±kf ac The spectrum diagram. For example... Figure 4C As shown, the resonant current i rp At switching frequency f s The maximum amplitude is at (n=1), and at the frequency (n·f) s +k·f ac ) and frequency (n·f s -k·f ac They have the same amplitude at point ).

[0110] Also refer to Figure 3A , Figure 3B , Figure 4A ,and Figure 4B Power equals voltage multiplied by current, due to capacitance C. rp It will block the resonant current i rp The DC component and low-frequency component in the equation, therefore the voltage V in equation 3. c And the voltage v in equation 4 rp,k (t) No work is done. Also refer to... Figure 3C and Figure 4C Resonant slot voltage V rp The main work components include the switching frequency f s The fundamental frequency voltage V of the resonant slot doing work rp1 and at frequency (f s ±k·f ac The low-order sideband frequency resonant voltage at which work is done, i.e., voltage v. rp1,sbk .

[0111] Figure 5 Embodiments of the present invention Figure 1 The resonant slot impedance |Z in resonant circuit 102 pn | and switching frequency f s A graph showing the relationship between the frequency of harmonics and the frequency of harmonics. For example... Figure 5 As shown, the resonant tank impedance |Z pn |At frequency switching fs The minimum value is located nearby, and the switching frequency f is... s That is, the resonant frequency or near the resonant frequency. Because the resonant tank impedance |Z pn |At 3x switching frequency 3f s At 5 times the switching frequency 5f s The impedance at that point is much greater than the fundamental frequency impedance Z. p1 And the resonant slot impedance |Z pn |At low-order sideband frequencies (f s ±k·f ac The impedance value is close to the fundamental frequency impedance Z. p1 Therefore, the resonant slot voltage V rp The main work components include the switching frequency f s The fundamental frequency voltage V of the resonant slot doing work rp1 and at frequency (f s ±k·f ac The low-order sideband frequency resonant voltage v that does work at point ) rp1,sbk .

[0112] Figure 6 Embodiments of the present invention Figure 1 The first fundamental frequency current i in the resonant circuit 102 rp,BPF (t), low-frequency current i rpPDC (t) and the peak value of the fundamental frequency current I rpPDC The waveform diagram. Figure 6 First, the first fundamental frequency current i generated after filtering by bandpass filter 108 is disclosed. rp,BPF (t) in Waveform diagram within the period. Wherein, the AC period T... ac AC power supply V ac frequency f ac The reciprocal of this can be, for example, the reciprocal of the mains frequency of 60Hz. Next, the peak detection circuit 112 measures the first base frequency current i... rp,BPF (t) Perform peak detection to generate Figure 6 Low-frequency current i in rp,PDC (t). Peak fundamental frequency current I rp,PDC That is, the low-frequency current i rp,PDC (t) is the maximum value of the amplitude.

[0113] In detail, the first fundamental frequency current i rp,BPF (t) can be expressed by the following formula 8.

[0114]

[0115] In equation 8, i rp1 (t)=I rp1 sin(2πf s +θi1 (Equation 9). I rp1 For the peak value of the fundamental frequency current, θ i1 This is the phase of the fundamental frequency current.

[0116] In equation 8, i rp1,sbk (t)=I rp1,sbk sin[(f s ±kf ac )2πt+θ i1 (Equation 10). I rp1,sbk The base frequency (i.e., the switching frequency f) s The peak current at approximately k times the sideband frequency. Specifically, the low-frequency current i... rp，PDC (t) can be expressed by the following formula 11.

[0117]

[0118] Using the Taylor series expansion of the arctangent function, equation 11 can be rewritten as equation 12.

[0119]

[0120] When cos(2kπf) ac If t) = 1, then i can be obtained. rp,PDC The peak value of (t), i.e., the peak value of the fundamental frequency current I. rp,PDC It can be expressed by the following formula 13.

[0121]

[0122] I rp1,sb2 The first sideband frequency (f) on either side of the fundamental frequency component s ±2f ac The peak value of ).

[0123] Figure 7 Embodiments of the present invention Figure 1 The resonant slot voltage V in resonant circuit 102 rp , fundamental frequency voltage V rp,BPF and the first fundamental frequency current i rp,BPF The waveform diagram. For example... Figure 7 As shown, the resonant tank voltage V rp For amplitudes higher than 200V and with a switching period T s The square wave signal. Resonant slot voltage V rp The duty cycle is 50%. Switching cycle T s For switching frequency f s The reciprocal of. In some embodiments, if the bandpass filter 108 affects the resonant tank voltage v rpAfter filtering, a voltage of 200V with a switching period T can be obtained. s The fundamental frequency voltage V rp,BPF Fundamental frequency voltage V rp,BPF It is a sine wave signal. Figure 7 Next, the first fundamental frequency current i generated after being filtered by bandpass filter 108 is disclosed. rp,BPF The waveform diagram. For example... Figure 7 As shown, the fundamental frequency voltage V rp,BPF The waveform passes through the voltage 0 point at the same time as the resonant tank voltage V. rp The timing of the rising edge. Therefore, this invention does not require prior knowledge of the base frequency voltage V. rp,BPF Instead, the first fundamental frequency current i is directly calculated by the phase detection circuit 110. rp,BPF and resonant slot voltage V rp Phase difference θ of the rising edge v1-i1 .

[0124] Figure 8A The input power P calculated by the processor 114 in this embodiment of the invention r Based on switching frequency f s The spectrum diagram. For example... Figure 8A As shown, the input power P r At switching frequency f s The maximum amplitude is at and near (n=1).

[0125] Figure 8B The input power P calculated by the processor 114 in this embodiment of the invention r Based on switching frequency f s and sideband frequency f s ±kf ac The spectrum diagram. For example... Figure 8B As shown, the input power P r At switching frequency f s The maximum amplitude, i.e., the fundamental frequency power, is located at (n=1). Input power P r At low-order sideband frequencies (f s ±k·f ac There is a second large amplitude at (), which is the maximum sideband power.

[0126] In detail, the input power P r It can be expressed by the following formula 14.

[0127]

[0128] In equation 14,

[0129] In equation 14,

[0130] By substituting equation 13 into equation 14, equation 1 can be obtained.

[0131] Figure 9A Embodiments of the present invention Figure 1 A complete schematic diagram of the resonant circuit 102. Figure 9A In this embodiment, the resonant circuit 102 is a wireless power transmission circuit consisting of two series-connected resonant circuits. Figure 9A In one embodiment, the resonant circuit 102 includes an AC power supply V. ac Diodes D1, D2, D3, and D4; Capacitor C in transistor Q h transistor Q l Inductor L rp Capacitor C rp and inductor L m AC power supply V ac One end is electrically connected to the first terminal of diode D1 and the second terminal of diode D2. AC power supply V ac The other end is electrically connected to the first terminal of diode D3 and the second terminal of diode D4. The second terminal of diode D1 is electrically connected to the second terminal of diode D3. The first terminal of diode D2 is electrically connected to the first terminal of diode D4. Diodes D1, D2, D3, and D4 utilize the physical characteristic that signals can only pass from their first terminal to their second terminal, but not from their second terminal to their first terminal, to supply AC power V. ac The output signal is rectified to obtain the input current i. in and generated from capacitance C in Input voltage v at both ends in Capacitor C in The two ends are respectively connected across the second end of diode D3 and the first end of diode D4.

[0132] transistor Q h The control terminal receives the drive signal G from the gate drive circuit 106. oh Transistor Q h The first terminal is electrically connected to the second terminal of diode D3. Transistor Q h The second terminal is electrically connected to transistor Q. l The first terminal. Transistor Q. l The control terminal receives the drive signal G from the gate drive circuit 106. ol Transistor θ l The first terminal is electrically connected to the inductor L rp Transistor Q l The second terminal is electrically connected to the first terminal of diode D4 and capacitor C. rp The resonant slot of the resonant circuit 102 includes an inductor L. rpCapacitor C rp and inductor L m However, the present invention is not limited thereto. Inductor L m For example, this could be the magnetizing inductance contributed by transformer T1. Transistor Q l The voltage across the first and second terminals is equal to the resonant slot voltage V. rp From transistor Q h The second end flows to inductor L rp The current is equal to the resonant current i rp .

[0133] exist Figure 9A In this embodiment, the resonant circuit 102 further includes a transformer T1 and an inductor L. rs Capacitor C rs and load resistance R eq The turns ratio of the primary and secondary sides of transformer T1 is n:1. The primary side of transformer T1 is electrically connected to inductor L. rp and capacitor C rp Between. The secondary side of transformer T1 is electrically connected to inductor L. rs and capacitor C rs Between. The secondary side of transformer T1 is based on the resonant current i of its primary side. rp Induction generates output current i o When the output current i o Flow through load resistor R eq The corresponding output voltage V is generated o Output voltage V o For communication signals.

[0134] exist Figure 9A In the embodiment, the output power P o It can be expressed by the following formula 17.

[0135]

[0136] In equation 17, P r It can be represented by equation 1. P coil This refers to the loss between the wireless power transmission coils.

[0137] Figure 9B Embodiments of the present invention Figure 1 A schematic diagram of the resonant circuit 102. Figure 9B and Figure 9A The difference lies in that the resonant circuit 102 includes, in addition to, a transformer T1 and an inductor L. rs Capacitor C rs and load resistance R eqIt also includes diodes D5, D6, D7, and D8. Diodes D5, D6, D7, and D8 form a full-wave rectifier circuit to rectify the secondary inductance L of transformer T1. rs and capacitor C rs AC voltage V between rs Output voltage V converted to DC o .

[0138] exist Figure 9B In the embodiment, the output power P o It can be expressed by the following formula 18.

[0139]

[0140] In equation 18, P r It can be represented by equation 1. P coil This refers to the loss between the wireless power transmission coils. diode This refers to the losses caused by full-wave rectification of the diode.

[0141] Figure 10 This is a flowchart illustrating a method for estimating the input power to the resonant slot in a resonant circuit, according to an embodiment of the present invention. Figure 10 As shown, the method for estimating the input power of the resonant slot in the resonant circuit according to the present invention includes: receiving the resonant current input to the resonant slot and filtering the resonant current to generate a first fundamental frequency current (step S1000); calculating the phase difference between the first fundamental frequency current and the resonant slot voltage (step S1002); generating the fundamental frequency current peak value based on the first fundamental frequency current (step S1004); performing a fast Fourier transform on the resonant slot voltage to obtain the resonant slot fundamental frequency voltage (step S1006); and calculating the input power based on the resonant slot fundamental frequency voltage, the fundamental frequency current peak value, and the phase difference (step S1008).

[0142] In some embodiments, step S1000 may be, for example, by Figure 1 The bandpass filter 108 performs this step. Step S1002 can be performed, for example, by... Figure 1 The phase detection circuit 110 performs this step. Step S1004 can be performed, for example, by... Figure 1 The peak detection circuit 112 performs the steps S1006 and S1008, for example, by... Figure 1 Executed by processor 114.

[0143] In some embodiments, step S1008 includes calculating the input power using the following formula: the formula is... P r For this input power, V rp1 I is the fundamental frequency voltage of the resonant slot. rp,PDCFor the peak value of the fundamental frequency current, and θ v1 -θ i1 This is the phase difference between the rising edges of the first fundamental frequency current and the resonant slot voltage.

[0144] In some embodiments, the method of estimating the input power input to the resonant slot in the resonant circuit further includes: receiving a reference input power and subtracting the reference input power from the input power to obtain a power difference; adjusting the input power according to the power difference to obtain a total input power; adjusting the frequency of a pulse signal according to the total input power and outputting a pulse signal; and driving the resonant circuit according to the pulse signal.

[0145] While embodiments of this disclosure are as described above, it should be understood that what is presented above is merely exemplary and not limiting. Many modifications to the exemplary embodiments described above can be made without departing from the spirit and scope of the disclosure. Therefore, the breadth and scope of this disclosure should not be limited by the embodiments described above. Rather, the scope of this disclosure should be defined by the following claims and their equivalents. Although the above disclosure has been illustrated and depicted by one or more related embodiments, equivalent changes and modifications will be conceived by others skilled in the art based on the above specifications and drawings. Furthermore, although a particular feature of this disclosure has been exemplified in one of the related embodiments, such feature may be combined with one or more other features to meet the needs and facilitate any known or particular application.

[0146] The technical terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. Unless the context clearly indicates otherwise, the singular form used herein, as well as the plural form, also includes the meaning of the foregoing. Furthermore, the terms "comprising," "including," "(having)," "equipped with," or variations thereof are used either as part of a detailed description or as part of the scope of the claims. The foregoing terms mean "comprising" and are, to some extent, equivalent to the term "comprising." Unless otherwise defined, all terms used herein (including technical or scientific terms) are to be understood by one of ordinary skill in the art as described above. It should be further understood that the foregoing terms, as defined in commonly used dictionaries, should be interpreted in the context of the relevant art. Unless expressly defined herein, the foregoing terms are not to be construed as idealized or overly formal.

Claims

1. An electronic device for calculating an input power input to a resonant slot in a resonant circuit, comprising: A bandpass filter receives a resonant current input to the resonant slot and filters the resonant current to generate a first fundamental frequency current; A phase detection circuit, electrically connected to the bandpass filter, is used to calculate a phase difference between the first fundamental frequency current and the voltage input to the resonant tank. A peak detection circuit, electrically connected to the bandpass filter, is used to generate a fundamental frequency current peak based on the first fundamental frequency current; as well as A processor, electrically connected to the phase detection circuit and the peak detection circuit, performs a fast Fourier transform on the resonant tank voltage to obtain a resonant tank fundamental frequency voltage. The processor calculates the input power based on the fundamental frequency voltage of the resonant slot, the peak value of the fundamental frequency current, and the phase difference.

2. The electronic device as claimed in claim 1, wherein, The processor calculates the input power using the following formula: Among them, P r For this input power, V rp1 I is the fundamental frequency voltage of the resonant slot. rp,PDC For the peak value of the fundamental frequency current, and θ v1 -θ i1 This is the phase difference between the rising edges of the first fundamental frequency current and the resonant slot voltage.

3. The electronic device of claim 1, further comprising: A subtractor, electrically connected to the processor, receives a reference input power and the input power from the processor, and subtracts the reference input power from the input power to obtain a power difference.

4. The electronic device of claim 3, further comprising: A power regulator, electrically connected to the subtractor, adjusts the input power based on the power difference to obtain a total input power.

5. The electronic device of claim 4, further comprising: A pulse frequency modulation circuit is electrically connected to the power regulator. Based on the total input power, it adjusts the frequency of a pulse signal and outputs the pulse signal.

6. The electronic device of claim 4, further comprising: A gate driving circuit is electrically connected to the pulse frequency modulation circuit and drives the resonant circuit according to the pulse signal.

7. The electronic device as claimed in claim 1, wherein, The input power includes a fundamental frequency power and a maximum sideband power.

8. The electronic device as claimed in claim 1, wherein, The resonant circuit is an inductor-inductor-capacitor (LLC) circuit, or the resonant circuit used for wireless power transmission, or the resonant circuit of an induction cooker.

9. A method for estimating an input power input to a resonant slot in a resonant circuit, comprising: A resonant current is received input to the resonant slot, and the resonant current is filtered to generate a first fundamental frequency current; Calculate the phase difference between the first fundamental frequency current and a resonant tank voltage input to the resonant tank; A fundamental frequency current peak is generated based on the first fundamental frequency current; Perform a fast Fourier transform on the resonant tank voltage to obtain a resonant tank fundamental frequency voltage; as well as The input power is calculated based on the fundamental frequency voltage of the resonant slot, the peak value of the fundamental frequency current, and the phase difference.

10. The estimation method as described in claim 9, wherein, The steps for calculating the input power based on the fundamental frequency voltage of the resonant slot, the peak value of the fundamental frequency current, and the phase difference include: The input power is calculated using a formula; where the formula is: Among them, P r For this input power, V rp1 I is the fundamental frequency voltage of the resonant slot. rp,PDC For the peak value of the fundamental frequency current, and θ v1 -θ i1 This is the phase difference between the rising edges of the first fundamental frequency current and the resonant slot voltage.

11. The estimation method as described in claim 9, further comprising: Receive a reference input power and subtract the input power from the reference input power to obtain a power difference; The input power is adjusted based on the power difference to obtain a total input power; Based on the total input power, adjust the frequency of a pulse signal and output the pulse signal; as well as The resonant circuit is driven based on the pulse signal.

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