System and method for improving near field communication quality in electromagnetic induction heating scenarios

Abstract

This invention discloses a system and method for improving near-field communication quality in electromagnetic induction heating scenarios, including an energy receiving device and an energy transmitting device. The energy transmitting device generates an alternating electromagnetic field and transmits electromagnetic field energy and signal commands to the energy receiving device. The energy receiving device receives the energy emitted by the energy transmitting device, supplies power to electrical appliances, and receives signal commands. This invention utilizes the characteristics of a double-sideband T-type matching network and optimizes the component parameters of the matching network using electromagnetic field co-simulation design methods and optimization algorithms. While ensuring high-efficiency energy transmission, it significantly suppresses electromagnetic interference from low-frequency induction heating and improves placement freedom, thereby enabling intelligent communication of kitchen appliances in a dynamic kitchen environment with strong interference.

Description

Technical Field

[0001] This invention belongs to the field of improving near-field communication quality, specifically relating to a system and method for improving near-field communication quality in an electromagnetic induction heating scenario. Background Technology

[0002] Wireless power transfer technology has seen rapid adoption in consumer electronics in recent years due to its advantages such as convenience, safety, and contactless operation. As a significant extension of this technology into the kitchen setting, the wireless kitchen system based on the Wireless Power Consortium (WPC) Ki standard aims to provide up to 2200 watts of wireless power to various kitchen appliances via a transmitter coil embedded under the countertop. This completely eliminates the constraints of traditional power cords, achieving a cleaner kitchen countertop and more flexible space layout, representing the forefront of smart home development. However, the Ki system faces multiple intertwined technical bottlenecks in practical application: to achieve a "place and charge" user experience, greater freedom in device placement is necessary, but this significantly reduces energy transfer efficiency; strong electromagnetic interference generated by high-power appliances can severely affect NFC communication, rendering smart communication between the transmitter and kitchen appliances unusable. How to ensure high-efficiency energy transfer while simultaneously maintaining anti-interference capabilities and high placement flexibility is the core challenge in the current Ki system design.

[0003] For example, Zhen Zhang et al. published a paper titled "Optimal Design of Quadrature-Shaped Pickup for Omnidirectional Wireless Power Transfer" in IEEE TRANSACTIONS ON MAGNETICS. This paper proposes a new coil structure that can change the direction of the magnetic field generated by the coil. By using the orthogonal magnetic field directions generated by the two power transfer systems, the electromagnetic coupling between the induction heating system and the near-field communication system can be reduced. However, this method increases the size of the system, and since the coil structure requires two excitation circuits, it undoubtedly increases the integration complexity of the system.

[0004] For example, Zhedong Ma et al. published a paper titled "A Wireless Charging and NFC Integration Technique Based on High-frequency Impedance Characterization of Wireless Charging Coils" in the IEEE Applied Power Electronics Conference and Exposition journal. This paper integrates the charging coil and the NFC coil together, dividing the coil into two parts by a pin. Although this integration method reduces space costs, it avoids the working time of the two systems in the time domain, which greatly affects the working efficiency of the induction heating system.

[0005] Existing technologies face numerous challenges in induction heating and near-field communication collaborative systems. On the one hand, employing time-domain avoidance methods (pausing heating for communication) interrupts energy transfer, affecting heating continuity and overall system efficiency. On the other hand, altering the coil structure to orthogonalize the magnetic fields generated by the two systems leads to increased device size and complex layout, making it difficult to meet the compact and integrated design requirements of modern kitchen appliances. Furthermore, existing matching network designs often struggle to suppress low-frequency electromagnetic interference generated by induction heating systems and maintain high-efficiency energy transfer. Summary of the Invention

[0006] To overcome the shortcomings of the existing technology, the present invention aims to provide a system and method for improving near-field communication quality in electromagnetic induction heating scenarios. This method utilizes the characteristics of a double-sideband T-type matching network and optimizes the component parameters of the matching network through electromagnetic field co-simulation design and optimization algorithms. While ensuring high-efficiency energy transmission, it significantly suppresses electromagnetic interference from low-frequency induction heating and improves the degree of freedom in placement, thereby enabling intelligent communication of kitchen appliances in a dynamic kitchen environment with strong interference.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A system for improving near-field communication quality in electromagnetic induction heating scenarios, comprising an energy receiving device and an energy transmitting device; The energy transmitting device is used to generate an alternating electromagnetic field and transmit electromagnetic field energy and signal commands to the energy receiving device. The energy receiving device is used to receive energy emitted by the energy transmitting device, supply power to electrical appliances, and receive signal commands.

[0008] The energy emission device includes an induction heating emission coil C1, an induction heating module emission end excitation circuit A, a near-field communication emission coil C2, and a near-field communication module emission end excitation circuit B; The excitation circuit A at the emitter end of the induction heating module is used to generate low-frequency alternating current and control the input power; The low-frequency current is passed into the induction heating transmitting coil C1 to generate an alternating magnetic field for induction heating and to emit electromagnetic field energy into space. The near-field communication module transmitter excitation circuit B is used to generate high-frequency alternating current and transmit high-frequency oscillation signals; The high-frequency current is passed into the near-field communication transmitting coil C2 to generate an alternating magnetic field for near-field communication and to transmit near-field communication signals into space. The excitation circuit A of the induction heating module transmitter is connected in sequence by a 50Hz sinusoidal AC source E1, a rectifier circuit D1, an IGBT switch S1, and a compensation network N1. In the excitation circuit A of the induction heating module transmitter, the compensation network N1 is connected to the induction heating transmitter coil C1; The near-field communication module transmitter excitation circuit B includes a DC excitation source E2, an NFC transmitter chip, a MOSFET switch S2, a balun transformer T, and a double-sideband T-type matching network N2 connected in sequence. The modulation signal generated by the DC excitation source E2, MOSFET switch S2, balun transformer T, and double-sideband T-type matching network N2 controls the operation of the MOSFET switch S2. The near-field communication transmitter coil C2 is connected to the near-field communication module transmitter excitation circuit B via the double-sideband T-type matching network N2.

[0009] The energy receiving device includes an induction heating receiving coil C3, an induction heating receiving circuit C, a near-field communication receiving coil C4, and a near-field communication receiving circuit D; The induction heating receiving coil C3 is placed in the alternating magnetic field generated by the induction heating transmitting coil C1 to generate an induced electromotive force for power supply. The induction heating receiving circuit C is used to transmit the induced electromotive force generated by the induction heating receiving coil C3 to the electrical load. The near-field communication receiving coil C4 is used to receive the high-frequency oscillation signal emitted by the near-field communication transmitting coil C2; The near-field communication receiving circuit D is used to convert high-frequency oscillation signals into encoded signals for transmission to the NFC chip for processing.

[0010] The induction heating receiving circuit C includes a compensation network N3 and an equivalent resistance R1 of the kitchen appliance connected in sequence. The induction heating receiving coil C3 is connected to the induction heating receiving circuit C through the compensation network N3; The near-field communication receiving circuit D is composed of a double-sideband T-type matching network N4, a rectifier circuit D2, and an equivalent resistor R2 of the NFC receiving chip connected in sequence. The near-field communication receiving coil C4 is connected to the near-field communication receiving circuit D through a double-sideband T-type matching network N4.

[0011] The induction heating module consists of an induction heating transmitting coil C1, an induction heating module transmitting end excitation circuit A, an induction heating receiving coil C3, and an induction heating receiving circuit C. The induction heating module is used to transmit energy to electrical appliances, enabling non-plug-in energy supply.

[0012] The near-field communication module consists of a near-field communication transmitting coil C2, a near-field communication module transmitting end excitation circuit B, a near-field communication receiving coil C4, and a near-field communication receiving circuit D. The near-field communication module is used to realize bidirectional signal transmission and identification between the energy transmitting device and the energy receiving device.

[0013] Based on the above system, a method for improving near-field communication quality in electromagnetic induction heating scenarios specifically includes the following steps: The entire system workflow is that the near-field communication module works and generates commands to control the induction heating module. Specifically: In the near-field communication module's transmitter excitation circuit B, the MOSFET switch S2, controlled by the NFC transmitter chip, converts the voltage signal from the DC source E2 into a signal with a center frequency of... f The modulation signal of 0 is transmitted by the near-field communication transmitting coil C2 through the double-sideband T-type matching network N2, received by the near-field communication receiving coil C4, and then converted into an encoded signal by the rectifier circuit D2 in the near-field communication receiving circuit D. It is then transmitted to the NFC receiving chip for processing through the double-sideband T-type matching network N4, thereby issuing a command to control the operation of the induction heating module. When the induction heating module is started, the 50Hz AC voltage in the excitation circuit A of the induction heating module is converted into DC by the rectifier circuit D1, and then AC is generated by the IGBT switch S1, which generates an alternating magnetic field through the induction heating transmitting coil C1. The induction heating receiving coil C3, placed in an alternating magnetic field, generates an induced electromotive force to power the equivalent resistance R1 of the kitchen appliance. During this period, the near-field communication module can still send commands to adjust the working state of the induction heating module, enabling the kitchen appliance to operate in different modes.

[0014] The double-sideband T-type matching network N2 and the double-sideband T-type matching network N4 have the same topology and include a series capacitor C. S and C S1 Parallel capacitor C P ; The specific method for optimizing the parameters of the double-sideband T-type matching network is as follows: First, the coil model is modeled in three dimensions and simulated in the frequency domain in the three-dimensional electromagnetic field simulation software HFSS (High Frequency Structure Simulator) to obtain the initial S-parameters and Z-parameters. The initial value of the capacitance of the double-sideband T-type matching network is estimated by using the Z-parameters and the equivalent A-parameters of the double-sideband T-type matching network. Then, the impedance and bandwidth targets are preset in the circuit analysis software ADS, and the genetic algorithm is started to automatically adjust the design parameters. Finally, high-precision verification is performed through joint field-circuit simulation using Maxwell and Simplier. If the simulation results do not meet the preset target, the parameters are optimized again. This "optimization-verification" process will be iterated until the performance meets the target, and finally the optimal design result is output.

[0015] By optimizing the parameters of the double-sideband T-network, low-frequency induction heating noise is suppressed, impedance matching is achieved, and power transmission efficiency and placement freedom are improved.

[0016] The coil model consists of an induction heating transmitting coil C1, an induction heating receiving coil C3, a near-field communication transmitting coil C2, a near-field communication receiving coil C4, and a magnetic strip; The induction heating transmitting coil C1, the induction heating receiving coil C3, the near-field communication transmitting coil C2, and the near-field communication receiving coil C4 are arranged in a stacked layout in space. With the Z-axis as the reference, the structure from top to bottom is as follows: receiving magnetic strip 1, induction heating receiving coil C3 and near-field communication receiving coil C4, near-field communication transmitting coil C2, induction heating transmitting coil C1 and transmitting magnetic strip 2; Among them, the induction heating receiving coil C3 and the near-field communication receiving coil C4 are in the same layer and coaxial, and the inner diameter of coil C4 is larger than the outer diameter of coil C3.

[0017] Both the induction heating transmitting coil C1 and the induction heating receiving coil C3 are multi-turn planar spiral coils; the near-field communication transmitting coil C2 is an open ring structure, and the near-field communication receiving coil C4 is a ring, both made of wire; the receiving magnetic strip 1 and the transmitting magnetic strip 2 are both long strips, arranged in an array around the axis, for electromagnetic shielding and to enhance the induction heating effect.

[0018] The coil model is equivalent to a four-port network, with the near-field communication transmitting coil C2 having port 1 and its source impedance being Z. S The near-field communication receiving coil C4 is set at port 2, and its load impedance is Z. L The induction heating transmitting coil C1 is located at port 3, and its source impedance is Z. S1The induction heating receiving coil C3 is located at port 4, and its load impedance is Z. L1 In the electromagnetic simulation software, set to... Frequency domain simulation was performed with the center frequency and BW as the simulation bandwidth to obtain the S-parameter and Z-parameter matrices of the four-port network. Equations (1) and (2) were obtained from the Z-parameter network definition and the voltage-current relationship of the ports, respectively: (1) (2) In formula (1) For when except the first i When all ports except for one are open, port i The input impedance; ( i ≠ j ) for when except the first j When all ports except for one are open, port j With port i The transfer impedance between them.

[0019] The input impedance of the four-port network is calculated by taking port 1 as an example. The other current components in the equation are used This is represented as shown in equation (3): (3) Finally, we get Z. in The expression is shown in (4): (4) To obtain the input impedance Z after cascading a double-band T-type matching network and a four-port network. eq Starting from the definition of the A-parameter matrix, the double-sideband T-type matching network is equivalent to a two-port network, and its A-parameter matrix expression is obtained as shown in equation (5): (5) Based on the impedance transformation properties of the A-parameter matrix and the already derived Z... in From the A-parameter matrix, the input impedance Z of the cascaded double-sideband T-type matching network and four-port network is obtained. eq As shown in equation (6): (6) Substituting equations (4) and (5) into equation (6), and taking ω as respectively , ,and The frequency was obtained as Z of time eq0 The expression and frequency are Z eq1 The expression, and the frequency is Z eq2 The expression; according to the conjugate matching condition, to maximize the input power of the near-field communication transmitting coil, it is necessary to make... (7) To ensure that the characteristics of the double-sideband T-type matched network meet the required bandwidth, based on the obtained Z... eq1 and Z eq2 Substitute into (8) and (9) to calculate in VSWR1 and VSWR2 at the location, (8) ( m =1,2) (9) According to formula (7), and Three conditions determine the value range for each capacitor: , , Select the optimal initial value for the capacitor from the range.

[0020] In circuit design software, construct the following circuits: A) Excitation circuit for the transmitter of the induction heating module; B) Excitation circuit for the transmitter of the near-field communication module; C) Induction heating receiving circuit; D) Near-field communication receiving circuit. The S-parameter file obtained from the electromagnetic simulation software is imported into the circuit design software to generate a four-port network element. Port 1 of the S-parameter file is connected to the excitation circuit B of the near-field communication module via a double-sideband T-type matching network N2, and port 2 is connected to the near-field communication receiving circuit D via a double-sideband T-type matching network N4. The compensation network N1 in the excitation circuit A of the induction heating module is connected to port 3 of the S-parameter file, and the compensation network N3 in the induction heating receiving circuit C is connected to port 4. The capacitance C of the capacitor elements in the double-sideband T-matching network N2 and N4 is... S C S1 and C P Set as a variable, C S exist Select an initial value within the range and set its range of variation as follows. C S1 exist Select an initial value within the range and set its range of variation as follows. C P exist Select an initial value within the range and set its range of variation as follows. ; The optimization target is set to The equivalent impedance within the simulated frequency band, where BW is the center frequency and BW is the simulated bandwidth. The genetic optimization algorithm is used to optimize the component parameters in the matching network.

[0021] The optimization process is as follows: First, a population is initialized, where each individual represents a set of potential configurations that match network parameters. The quality of each individual is evaluated based on metrics such as impedance, reflection coefficient, transmission coefficient, or bandwidth. Next, individuals with high fitness are selected for genetic operations: new combinations are generated by cross-matching each set of parameters or by randomly fine-tuning certain parameters, thereby producing the next generation of the population; after multiple generations of iteration, the parameter configuration of the population gradually evolves, and finally parameter values ​​that meet the optimization goal are obtained; Finally, a full-wave simulation verification was performed using a combination of electromagnetic simulation software and circuit design software to test whether the low-frequency electromagnetic interference was effectively suppressed when the induction heating system was working; and whether the received power met the requirements when the receiver was placed in different positions during the operation of the near-field communication system. If the full-wave simulation results did not meet the requirements, the optimization target and initial capacitor value were reset for a new round of parameter optimization and verification.

[0022] The beneficial effects of this invention are: 1. This invention achieves simultaneous operation of induction heating and near-field communication at the circuit level. The induction heating module coil and the near-field communication module coil adopt a stacked layout structure in space. Through the circuit topology of the double-sideband T-type matching network and the optimization of the matching network parameters by a genetic algorithm, this invention can effectively suppress electromagnetic interference generated by the low-frequency induction heating system without changing the shape of the coil, thereby greatly saving space costs. This suppression of low-frequency noise at the circuit level can be achieved simply by changing the circuit topology of the matching network on the PCB board, without having to change the planar coil to a more space-consuming three-dimensional coil structure. This has significant advantages when deploying the entire system in a Ki standard wireless kitchen system.

[0023] 2. After parameter optimization of the matching network, the near-field communication coil achieves impedance variation, enabling the entire near-field communication system to operate at... The system outputs maximum power at the same time. Simultaneously, the frequency selectivity of the matching network acts like a bandpass filter, suppressing low-frequency induction heating signal interference that deviates from the center frequency. This significantly attenuates the low-frequency signal components flowing to the coil, effectively suppressing low-frequency noise and ensuring that the interference voltage induced at the near-field communication receiver is below its normal operating threshold. The induction heating system and the near-field communication system operate independently, achieving continuous communication and improving both the heating efficiency of induction heating and the communication efficiency of near-field communication. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the induction heating and near-field communication system and its peripheral circuit modules in Embodiment 1 of the present invention.

[0025] Figure 2 The model of the induction heating coil, near-field communication coil, and ferrite magnetic stripe in HFSS finite element simulation software and Maxwell simulation software in Embodiment 1 of the present invention.

[0026] Figure 3 It is a double-sideband T-type matching network circuit structure.

[0027] Figure 4 This is a flowchart of network parameter optimization in Embodiment 1 of the present invention.

[0028] Figure 5 The four different placement methods for full-wave simulation in Embodiment 1 of the present invention are: (a) the transmitting and receiving coils are directly opposite each other with a spacing d of 10 mm; (b) the transmitting and receiving coils are directly opposite each other with a spacing d of 40 mm; (c) the transmitting and receiving coils are offset by a distance a of 40 mm with a spacing d of 10 mm; and (d) the transmitting and receiving coils are offset by a distance a of 40 mm with a spacing d of 40 mm.

[0029] Figure 6 for Figure 5 (a) The coil is placed in the middle case, and the instantaneous power waveform of the receiver load of the near-field communication system is simulated in the full wave.

[0030] Figure 7 for Figure 5 (b) The coil is placed in the middle case, and the instantaneous power waveform of the receiver load of the near-field communication system is simulated in the full wave.

[0031] Figure 8 for Figure 5 (c) The coil is placed in the middle case, and the instantaneous power waveform of the receiver load of the near-field communication system is simulated in the full wave.

[0032] Figure 9 for Figure 5 (d) The coil is placed in the middle case, and the instantaneous power waveform of the receiver load of the near-field communication system is simulated in the full wave.

[0033] Figure 10 This is the voltage waveform generated on the induction heating coil by the excitation of a single-tube heating circuit.

[0034] Figure 11 According to Embodiment 1 of the present invention Figure 4 In case (a), the coil is placed to excite the induction heating excitation circuit, and the voltage waveform at both ends of the receiver load of the near-field communication system is simulated in full-wave simulation. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings.

[0036] like Figure 1 As shown, a method for improving near-field communication quality in an electromagnetic induction heating scenario includes: The system used to implement the method of the present invention is as follows: Figure 1 As shown, the device includes an energy receiving device and an energy transmitting device. The energy transmitting device consists of an induction heating transmitting coil C1, an induction heating module transmitter excitation circuit A, a near-field communication transmitting coil C2, and a near-field communication module transmitter excitation circuit B. The induction heating module transmitter excitation circuit A is composed of a 50Hz sinusoidal AC source E1, a rectifier circuit D1, an IGBT switch S1, and a compensation network N1 connected in sequence. The compensation network N1 in the induction heating module transmitter excitation circuit A is connected to the induction heating transmitting coil C1. The near-field communication module transmitter excitation circuit B consists of a DC excitation source E2, an NFC chip, a MOSFET switch S2, a balun transformer T, and a double-sideband T-type matching network N2. The DC excitation source E2, MOSFET switch S2, balun transformer T, and matching network N2 are connected in sequence, and the modulation signal generated by the NFC transmitting chip controls the operation of the MOSFET switch S2. The near-field communication transmitting coil C2 is connected to the near-field communication module transmitter excitation circuit B via the double-sideband T-type matching network N2.

[0037] The energy receiving device consists of an induction heating receiving coil C3, an induction heating receiving circuit C, a near-field communication receiving coil C4, and a near-field communication receiving circuit D. The induction heating receiving circuit C is constructed by sequentially connecting a compensation network N3 to the equivalent resistance R1 of the kitchen appliance. The induction heating receiving coil C3 is connected to the induction heating receiving circuit C through the compensation network N3. The near-field communication receiving circuit D is constructed by sequentially connecting a double-sideband T-type matching network N4, a rectifier circuit D2, and the equivalent resistance R2 of the NFC receiving chip. The near-field communication receiving coil C4 is connected to the near-field communication receiving circuit D through the matching network N4.

[0038] The induction heating module consists of an induction heating transmitting coil C1, an induction heating module transmitting end excitation circuit A, an induction heating receiving coil C3, and an induction heating receiving circuit C; the near-field communication module consists of a near-field communication transmitting coil C2, a near-field communication module transmitting end excitation circuit B, a near-field communication receiving coil C4, and a near-field communication receiving circuit D.

[0039] The entire system workflow is as follows: the near-field communication module operates and generates commands to control the induction heating module. Specifically, in the near-field communication module's transmitter excitation circuit B, the MOSFET switch S2, controlled by the NFC transmitter chip, converts the voltage signal from the DC source E2 into a signal with a center frequency of... fThe modulated signal of 0 is emitted by the near-field communication transmitting coil C2 through the double-sideband T-matching network N2, received by the near-field communication receiving coil C4, and then converted into an encoded signal by the rectifier circuit D2 in the near-field communication receiving circuit D. This signal is then transmitted to the NFC receiving chip via the double-sideband T-matching network N4 for processing, thereby issuing commands to control the operation of the induction heating module. When the induction heating module starts, the 50Hz AC voltage in the induction heating module's transmitting end excitation circuit A is rectified into DC by the rectifier circuit D1, and then the AC circuit is generated by the IGBT switch S1. This generates an alternating magnetic field through the induction heating transmitting coil C1. When the induction heating receiving coil C3 is placed in the alternating magnetic field, an induced electromotive force is generated according to Faraday's law of electromagnetic induction, supplying power to the kitchen appliances. During this period, the near-field communication module can still send commands to adjust the operating state of the induction heating module, allowing the kitchen appliances to operate in different modes.

[0040] The described double-sideband T-type matching network structure is as follows: Figure 3 As shown, the series capacitor C S and C S1 Parallel capacitor C P .

[0041] The flowchart of the parameter optimization method for the double-sideband T-type matching network is as follows: Figure 4 As shown: First, the coil model is 3D modeled and frequency domain simulated in HFSS to obtain initial S-parameters and Z-parameters. The initial value of the matching network capacitance is estimated using the Z-parameters and A-parameters. Then, in the circuit analysis software ADS, targets such as impedance and bandwidth are preset, and a genetic algorithm is activated to automatically adjust the design parameters. Finally, high-precision verification is performed through joint field-circuit simulation using Maxwell and Simplier. If the simulation results do not meet the preset targets, the parameters are optimized again. This "optimization-verification" process iterates continuously until the performance meets the standards, ultimately outputting the optimal design result. By optimizing the parameters of the double-sideband T-type network, low-frequency induction heating noise is suppressed, impedance matching is achieved, and power transmission efficiency and placement freedom are improved.

[0042] A coil model of the induction heating module and the near-field communication module is established in electromagnetic simulation software. The coil model is as follows: Figure 2As shown, it consists of an induction heating transmitting coil C1, an induction heating receiving coil C3, a near-field communication transmitting coil C2, a near-field communication receiving coil C4, and a magnetic strip. The induction heating coil and the near-field communication coil are arranged in a stacked layout in space; the structure from top to bottom is as follows: receiving magnetic strip (1), induction heating receiving coil C3 and near-field communication receiving coil C4 (induction heating receiving coil C3 and near-field communication receiving coil C4 are in the same layer, and the inner diameter of coil C4 is larger than the outer diameter of coil C3), near-field communication transmitting coil C2, induction heating transmitting coil C1, and transmitting magnetic strip (2); both induction heating transmitting coil C1 and induction heating receiving coil C3 are multi-turn planar spiral coils; near-field communication transmitting coil C2 is an open circular ring structure, and near-field communication receiving coil C4 is a circular ring, both of which are wound with wire; the receiving magnetic strip (1) and the transmitting magnetic strip (2) are both long strips, arranged in an array around the axis for electromagnetic shielding and to enhance the induction heating effect.

[0043] The coil model is equivalent to a four-port network, with the near-field communication transmitting coil C2 having port 1 and its source impedance being Z. S The near-field communication receiving coil C4 is set at port 2, and its load impedance is Z. L The induction heating transmitting coil C1 is located at port 3, and its source impedance is Z. S1 The induction heating receiving coil C3 is located at port 4, and its load impedance is Z. L1 .

[0044] Settings The simulation frequency band centered on the network is used for frequency domain simulation to obtain the S-parameter matrix and Z-parameter matrix of the four-port network. The obtained S-parameters can be used to make a preliminary evaluation of the system's energy transmission efficiency and matching condition. The obtained Z-parameter matrix can extract the physical essence of the coil, such as self-inductance and mutual inductance, and is used to calculate the coupling coefficient and design the matching network in the future. From the Z-parameter network definition and the voltage and current relationship of the ports, equations (10) and (11) are obtained respectively: (10) (11) In the formula Let be the input impedance of port i when all ports except the i-th port are open. (i≠j) is the transfer impedance between port j and port i when all ports except the j-th port are open.

[0045] Furthermore, taking port 1 as an example, in order to determine the input impedance of port 1... The other current components in the equation are used This is represented as shown in equation (12): (12) Finally, we get Z. in The expression is shown in (13): (13) To obtain the input impedance Z after cascading a double-band T-type matching network and a four-port network. eq This method starts from the definition of the A-parameter matrix, and equates the double-sideband T-type matching network structure to a two-port network, thus obtaining its A-parameter matrix expression, as shown in equation (14): (14) Based on the impedance transformation properties of the A-parameter matrix and the already derived Z... in From the A-parameter matrix, the input impedance Z of the cascaded double-sideband T-type matching network and four-port network is obtained. eq As shown in equation (15): (15) Substituting equations (13) and (14) into equation (15), and taking ω as respectively , ,and The frequency was obtained as Z of time eq0 The expression and frequency are Z eq1 The expression, and the frequency is Z eq2 The expression. According to the conjugate matching condition, to maximize the input power of the near-field communication transmitting coil, it is necessary to make... (16) To ensure that the characteristics of the double-sideband T-type matched network meet the required bandwidth, based on the obtained Z... eq1 and Z eq2 Substitute (17) and (18) into the calculation. VSWR1 and VSWR2 at the location, (17) ( m =1,2) (18) According to formula (16), and Three conditions determine the value range for each capacitor: , , Select the optimal initial value for the capacitor from the range.

[0046] The excitation circuits for the induction heating system and the near-field communication system are constructed in circuit design software. The S-parameter file obtained from the electromagnetic simulation software is imported into the circuit design software, generating four-port network elements. Port 1 of the S-parameter file is connected to the near-field communication module excitation circuit B via a double-sideband T-matching network N2, and port 2 is connected to the near-field communication receiving circuit D via a double-sideband T-matching network N4. The compensation network N1 in the induction heating module excitation circuit A is connected to port 3 of the S-parameter file, and the compensation network N3 in the induction heating receiving circuit C is connected to port 4. The capacitance value C of the capacitor elements in the double-sideband T-matching networks N2 and N4 is set... S C S1 and C P Set as a variable, C S exist Select an initial value within the range and set its range of variation as follows. C S1 exist Select an initial value within the range and set its range of variation as follows. C P exist Select an initial value within the range and set its range of variation as follows. The optimization target is set to... The equivalent impedance within the simulated frequency band, where BW is the center frequency and BW is the simulated bandwidth. A genetic optimization algorithm is used to optimize the component parameters in a matching network. The optimization process is as follows: First, a population is initialized, where each individual represents a potential configuration of the matching network parameters. The quality of each individual is evaluated based on indicators such as impedance, reflection coefficient, transmission coefficient, or bandwidth. Then, individuals with high fitness are selected for genetic operations: new combinations are generated by cross-pairing each set of parameters or by randomly fine-tuning certain parameters, thus producing the next generation of the population. After multiple generations of iteration, the parameter configuration of the population gradually evolves, finally obtaining parameter values ​​that meet the optimization objective.

[0047] Finally, a full-wave simulation verification was performed using a combination of electromagnetic simulation software and circuit design software to test whether the low-frequency electromagnetic interference was effectively suppressed when the induction heating system was working; and whether the received power met the requirements when the receiver was placed in different positions during the operation of the near-field communication system. If the full-wave simulation results did not meet the requirements, the optimization target and initial capacitor value were reset for a new round of parameter optimization and verification.

[0048] Example 1 This design method is implemented for induction heating systems and near-field communication systems of specific dimensions. The overall process consists of three steps: Step 1: Establish an electromagnetic model in the commercial software ANSYS HFSS and simulate the original model. In this embodiment, the induction heating transmitting coil is a multi-turn planar spiral coil wound with Litz wire, a wire diameter of 0.25mm, 100 turns, a diameter of 54mm–184mm, and 20 turns; the receiving coil has a wire diameter of 0.3mm, 20 turns, a diameter of 48mm–146mm, and 40 turns; the NFC transmitting coil is an open-loop ring structure wound with wire, a wire diameter of 0.5mm, consisting of two thin wires wound into one wire, 4 layers of open rings, an inner diameter of 115mm, and a spacing of 13.5mm between each layer of open rings; the NFC receiving coil has an inner diameter of 168mm, an outer diameter of 178mm, and a wire diameter of 0.5mm.

[0049] Step two: Calculate the initial values ​​of the matching network capacitance using formulas (19) to (24). For example... Figure 2 As shown, the induction heating coil and the NFC coil are arranged in a stacked structure, with the transmitting coil of the induction heating system at the bottom layer and the transmitting coil of the near-field communication system placed 10 mm above it; Figure 4 As shown, the distance between the receiver and the NFC transmitting coil is 10-40 mm, and the offset distance is 0-40 mm. Magnetic strips are distributed on the top and bottom sides to reduce the influence of the magnetic field on the circuit boards on both sides. They are made of ferrite material, are cuboid in shape, with a length of 60 mm, a width of 15 mm, and a thickness of 3 mm. Coil models of the induction heating system and the near-field communication system are established in electromagnetic simulation software. The transmitting NFC coil is set to port 1, with an impedance of 290Ω. The receiver's NFC coil setting port 2 has an impedance of 320Ω. The induction heating coil at the transmitting end is located at port 3, and its impedance is 50Ω. The receiving end induction heating coil is set at port 4, and its impedance is 50Ω. After modeling, simulation is performed to obtain the Z-parameter matrix and S-parameter matrix; based on the Z-parameter network definition and the voltage-current relationship at the port, equations (19) and (20) are obtained respectively: (19) (20) Taking port 1 as an example, in order to determine the input impedance of port 1... The other current components in the equation are used This is represented as shown in equation (21): (twenty one) Finally, we get Z. in The expression is shown in (22): (twenty two) The expression for the A-parameter matrix of the matching network is shown in equation (23): (twenty three) According to Z in From the A-parameter matrix, the input impedance Z after cascading is obtained. in0 As shown in equation (24): (twenty four) Substituting equations (22) and (23) into equation (24), and based on the conjugate matching condition and BW=1MHz, f 1,2 Combining the condition that the VSWR at 13.56±0.5 MHz is less than 1.5, the capacitance range of the three capacitor elements is calculated. Similarly, the same calculation method is used to calculate the capacitance value of the double-sideband T-type matching network at the near-field communication receiving coil end, and the obtained C... S C S1 With C P The initial capacitance value was used for simulation optimization. Then, a circuit model was built in the commercial software ADS, and the S-parameter file obtained from the electromagnetic simulation was imported and converted into an equivalent impedance element. A genetic optimization algorithm was then used to simulate and optimize the capacitance value of the matching network, resulting in the capacitance parameter C at the transmitter of the near-field communication coil. S = 720.6pF, C S1 =6.05nF and C P =464pF; Receiver capacitor parameter C S =278.7pF, C S1 =708.4pF and C P =201pF; Step 3: Establish the same electromagnetic model in the commercial software ANSYS Maxwell, and build the induction heating excitation circuit and near-field communication excitation circuit in the commercial software ANSYS Simulator. Perform joint field-circuit simulation verification. Add a double-sideband T-type matching network between the near-field communication excitation circuit and the coil equivalent model, and fill in the capacitance parameters from Step 2. When the offset distance is 0mm and the coil spacing is 10mm, excite the near-field communication excitation circuit. The simulated NFC receiver load receiving power is 13W. Figure 5 As shown, the power received by the NFC receiver is 1W higher than the proposed specification, with a load voltage of 63V. At an offset distance of 0mm and a coil spacing of 40mm, the simulated load receiving power is 2.4W. Figure 6As shown, the simulated NFC receiver's load receiving power is 4.5W, exceeding the proposed specification by 1W, with a load voltage of 27.5V. At an offset distance of 40mm and a coil spacing of 10mm, the simulated NFC receiver's load receiving power is 1.16W, exceeding the proposed specification by 0.5W. Figure 8 As shown, the output is 0.5W higher than the proposed specifications, with a load voltage of 19V, improving energy transfer efficiency and placement flexibility. Figure 9 The figure shows the voltage waveform generated on the induction heating coil by the single-tube heating circuit. The waveform shows that the voltage reaches its peak at approximately 5ms. Simulations show that when the offset distance is 0mm and the coil spacing is 10mm, the voltage across the NFC receiver load is 0.8mV at 5ms. Figure 10 As shown, the voltage is much smaller than the voltage generated at the load end when NFC is working, low-frequency electromagnetic interference is suppressed and will not interfere with the normal operation of the near-field communication system.

Claims

1. A system for improving near field communication quality in an electromagnetic induction heating scenario, characterized in that, Includes energy receiving equipment and energy transmitting equipment; The energy transmitting device is used to generate an alternating electromagnetic field and transmit electromagnetic field energy and signal commands to the energy receiving device. The energy receiving device is used to receive energy emitted by the energy transmitting device, supply power to electrical appliances, and receive signal commands; The energy emission device includes an induction heating emission coil C1, an induction heating module emission end excitation circuit A, a near-field communication emission coil C2, and a near-field communication module emission end excitation circuit B; The excitation circuit A at the emitter end of the induction heating module is used to generate low-frequency alternating current and control the input power; The low-frequency current is passed into the induction heating transmitting coil C1 to generate an alternating magnetic field for induction heating and to emit electromagnetic field energy into space. The near-field communication module transmitter excitation circuit B is used to generate high-frequency alternating current and transmit high-frequency oscillation signals; The high-frequency current is passed into the near-field communication transmitting coil C2 to generate an alternating magnetic field for near-field communication and to transmit near-field communication signals into space. The energy receiving device includes an induction heating receiving coil C3, an induction heating receiving circuit C, a near-field communication receiving coil C4, and a near-field communication receiving circuit D; The induction heating receiving coil C3 is placed in the alternating magnetic field generated by the induction heating transmitting coil C1 to generate an induced electromotive force for power supply. The induced electromotive force is transmitted to the electrical load through the induction heating receiving circuit C; The near-field communication receiving coil C4 is used to receive the high-frequency oscillation signal emitted by the near-field communication transmitting coil C2; The near-field communication receiving circuit D is used to convert high-frequency oscillation signals into encoded signals for transmission to the NFC chip for processing.

2. The system for improving near field communication quality in electromagnetic induction heating scenario according to claim 1, wherein, The excitation circuit A of the induction heating module transmitter is connected in sequence by a 50Hz sinusoidal AC source E1, a rectifier circuit D1, an IGBT switch S1, and a compensation network N1. In the excitation circuit A of the induction heating module transmitter, the compensation network N1 is connected to the induction heating transmitter coil C1; The near-field communication module transmitter excitation circuit B includes a DC excitation source E2, an NFC transmitter chip, a MOSFET switch S2, a balun transformer T, and a double-sideband T-type matching network N2 connected in sequence. The modulation signal generated by the DC excitation source E2, MOSFET switch S2, balun transformer T, and double-sideband T-type matching network N2 controls the operation of the MOSFET switch S2. The near-field communication transmitter coil C2 is connected to the near-field communication module transmitter excitation circuit B via the double-sideband T-type matching network N2.

3. The system for improving near field communication quality in electromagnetic induction heating scenario of claim 2, wherein, The induction heating receiving circuit C includes a compensation network N3 and an equivalent resistance R1 of the kitchen appliance connected in sequence. The induction heating receiving coil C3 is connected to the induction heating receiving circuit C through the compensation network N3; The near-field communication receiving circuit D is composed of a double-sideband T-type matching network N4, a rectifier circuit D2, and an equivalent resistor R2 of the NFC receiving chip connected in sequence. The near-field communication receiving coil C4 is connected to the near-field communication receiving circuit D through a double-sideband T-type matching network N4.

4. A system for improving near-field communication quality in an electromagnetic induction heating scenario according to claim 3, characterized in that, The induction heating module consists of an induction heating transmitting coil C1, an induction heating module transmitting end excitation circuit A, an induction heating receiving coil C3, and an induction heating receiving circuit C. The induction heating module is used to transmit energy to electrical appliances, enabling non-electric energy supply. The near-field communication module consists of a near-field communication transmitting coil C2, a near-field communication module transmitting end excitation circuit B, a near-field communication receiving coil C4, and a near-field communication receiving circuit D. The near-field communication module is used to realize bidirectional signal transmission and identification between the energy transmitting device and the energy receiving device.

5. A method for improving near field communication quality in electromagnetic induction heating scenario, based on the system implementation, characterized in that, Specifically, the following steps are included: The near-field communication module operates and generates commands to control the operation of the induction heating module; In the near-field communication module's transmitter excitation circuit B, the MOSFET switch S2, controlled by the NFC transmitter chip, converts the voltage signal from the DC source E2 into a signal with a center frequency of... f The modulation signal of 0 is transmitted by the near-field communication transmitting coil C2 through the double-sideband T-type matching network N2, received by the near-field communication receiving coil C4, and then converted into an encoded signal by the rectifier circuit D2 in the near-field communication receiving circuit D. It is then transmitted to the NFC receiving chip for processing through the double-sideband T-type matching network N4, thereby issuing a command to control the operation of the induction heating module. When the induction heating module is started, the 50Hz AC voltage in the excitation circuit A of the induction heating module is converted into DC by the rectifier circuit D1, and then AC is generated by the IGBT switch S1, which generates an alternating magnetic field through the induction heating transmitting coil C1. The induction heating receiving coil C3, placed in an alternating magnetic field, generates an induced electromotive force to power the equivalent resistance R1 of the kitchen appliance. During this period, the near-field communication module can still send commands to adjust the working status of the induction heating module, enabling the kitchen appliances to operate in different modes.

6. The method of claim 5, wherein, The double-sideband T-type matching network N2 and the double-sideband T-type matching network N4 have the same topology and include a series capacitor C. S and C S1 Parallel capacitor C P ; Port 1 of the S-parameter file is connected to the excitation circuit B of the near-field communication module via a double-sideband T-type matching network N2, and port 2 is connected to the near-field communication receiving circuit D via a double-sideband T-type matching network N4. The compensation network N1 in the excitation circuit A of the induction heating module is connected to port 3 of the S-parameter file, and the compensation network N3 in the induction heating receiving circuit C is connected to port 4. The specific method for optimizing the parameters of the double-sideband T-type matching network is as follows: First, the coil model is modeled in three dimensions and simulated in the frequency domain in the three-dimensional electromagnetic field simulation software HFSS to obtain the initial S-parameters and Z-parameters. The initial value of the capacitance of the double-sideband T-type matching network is estimated by using the Z-parameters and the equivalent A-parameters of the double-sideband T-type matching network. Then, the impedance and bandwidth targets are preset in the circuit analysis software ADS, and the genetic algorithm is started to automatically adjust the design parameters. Finally, high-precision verification was performed through joint field-circuit simulation using Maxwell and Simplier. If the simulation results did not meet the preset target, the parameters were optimized again. The process was iterated until the performance met the target, and the optimal design result was finally output.

7. The method of claim 6, wherein, The coil model consists of an induction heating transmitting coil C1, an induction heating receiving coil C3, a near-field communication transmitting coil C2, a near-field communication receiving coil C4, and a magnetic strip; The induction heating transmitting coil C1, the induction heating receiving coil C3, the near-field communication transmitting coil C2, and the near-field communication receiving coil C4 are arranged in a stacked layout in space. With the Z-axis as the reference, the structure from top to bottom is: receiving end magnetic strip (1), induction heating receiving coil C3 and near-field communication receiving coil C4, near-field communication transmitting coil C2, induction heating transmitting coil C1 and transmitting end magnetic strip (2). Among them, the induction heating receiving coil C3 and the near-field communication receiving coil C4 are in the same layer and coaxial, and the inner diameter of coil C4 is larger than the outer diameter of coil C3. Both the induction heating transmitting coil C1 and the induction heating receiving coil C3 are multi-turn planar spiral coils; the near-field communication transmitting coil C2 is an open ring structure, and the near-field communication receiving coil C4 is a ring, both of which are wound with wire; the receiving end magnetic strip (1) and the transmitting end magnetic strip (2) are both long strips, arranged in an array around the axis, for electromagnetic shielding and to enhance the induction heating effect.

8. The method of claim 5, wherein, The coil model is equivalent to a four-port network, with the near-field communication transmitting coil C2 having port 1 and its source impedance being Z. S The near-field communication receiving coil C4 is set at port 2, and its load impedance is Z. L The induction heating transmitting coil C1 is located at port 3, and its source impedance is Z. S1 The induction heating receiving coil C3 is located at port 4, and its load impedance is Z. L1 In the electromagnetic simulation software, set to... Frequency domain simulation was performed with the center frequency and BW as the simulation bandwidth to obtain the S-parameter and Z-parameter matrices of the four-port network. Equations (1) and (2) were obtained from the Z-parameter network definition and the voltage-current relationship of the ports, respectively: (1) (2) In formula (1) For when except the first i When all ports except for one are open, port i The input impedance; ( i ≠ j ) for when except the first j When all ports except for one are open, port j With port i The transfer impedance between them.

9. The method of claim 8, wherein, The input impedance of the four-port network, specifically port 1, is calculated. The other current components in the equation are used This is represented as shown in equation (3): (3) Finally, we get Z. in The expression is shown in (4): (4) From the definition of A parameter matrix, the double sideband T-type matching network is equivalent to a two-port network, and the expression of A parameter matrix is obtained. The input impedance Z of the double sideband T-type matching network after being connected with the four-port network is obtained eq As shown in equation (5): (5) According to the impedance transformation property of the A-parameter matrix and the already derived Z in and the A-parameter matrix, the input impedance Z eq as shown in equation (6): (6) Substituting equations (4) and (5) into equation (6), and taking ω as respectively , ,and The frequency was obtained as Z of time eq0 The expression and frequency are Z eq1 The expression, and the frequency is Z eq2 The expression; according to the conjugate matching condition, to maximize the input power of the near-field communication transmitting coil, it is necessary to make: (7) Based on the obtained Z eq1 and Z eq2 Substitute into (8) and (9) to calculate in VSWR1 and VSWR2 at the location, (8) （ m =1,2） (9) According to formula (7), and Three conditions determine the value range for each capacitor: , , Select the optimal initial value for the capacitor from the range; In circuit design software, construct the following circuits: A) Excitation circuit for the transmitter of the induction heating module; B) Excitation circuit for the transmitter of the near-field communication module; C) Induction heating receiving circuit; D) Near-field communication receiving circuit. The S-parameter file obtained from the electromagnetic simulation software is imported into the circuit design software to generate a four-port network element. Port 1 of the S-parameter file is connected to the excitation circuit B of the near-field communication module via a double-sideband T-type matching network N2, and port 2 is connected to the near-field communication receiving circuit D via a double-sideband T-type matching network N4. The compensation network N1 in the excitation circuit A of the induction heating module is connected to port 3 of the S-parameter file, and the compensation network N3 in the induction heating receiving circuit C is connected to port 4. The capacitance C of the capacitor elements in the double-sideband T-matching network N2 and N4 is... S C S1 and C P Set as a variable, C S exist Select an initial value within the range and set its range of variation as follows. C S1 exist Select an initial value within the range and set its range of variation as follows. C P exist Select an initial value within the range and set its range of variation as follows. ; The optimization target is set to be The equivalent impedance in the simulation frequency band with the center frequency of 2.4GHz and the BW of 100MHz The element parameters in the matching network are optimized by using a genetic optimization algorithm.

10. The method of claim 9, wherein, The optimization process is as follows: First, a population is initialized, where each individual represents a set of potential configurations that match network parameters. The quality of each individual is evaluated based on metrics such as impedance, reflection coefficient, transmission coefficient, or bandwidth. Next, individuals with high fitness are selected for genetic manipulation: new combinations are generated by cross-matching each set of parameters or by randomly fine-tuning certain parameters, thereby producing the next generation of the population; Through multiple generations of iteration, the parameter configuration of the population gradually evolves, eventually yielding parameter values ​​that meet the optimization objective. Finally, a full-wave simulation verification was performed using a combination of electromagnetic simulation software and circuit design software to test whether it effectively suppressed low-frequency electromagnetic interference when the induction heating system was working. Furthermore, when the near-field communication system is in operation, whether the received power meets the requirements when the receiver is placed in different positions. If the full-wave simulation results do not meet the requirements, the optimization target and initial capacitor value are reset for a new round of parameter optimization and verification.

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