A Wide-Range Information Transmission Design Method Based on an Improved LCC Compensation Topology with Dual Resonant Frequencies

Abstract

The present invention discloses a wide-range information transmission design method based on an improved LCC compensation topology structure with double resonance frequencies. Analyze the frequency characteristics of the existing LCC compensation topology circuit, and build a magnetic communication circuit with an improved LCC compensation topology structure; establish an equivalent circuit model of the improved magnetic communication circuit; analyze the transmission characteristics of the magnetic coupling communication transmission system, and compare the transmission characteristics with the target value. If the target value is reached, end the process. If the target value is not reached, adjust the parameters of the magnetic coupling communication transmission system; iterate until the information transmission characteristics reach the target value. The present invention aims to solve problems such as weak transmission signals caused by a small coupling coefficient and an increased information transmission error rate due to changes in the coupling coefficient caused by distance variations in existing wireless power transmission systems.

Description

Technical Field

[0001] The present invention belongs to the field of wireless power transmission; specifically, it relates to a wide-range information transmission design method based on an improved LCC compensation topology structure with dual resonant frequencies. Background Art

[0002] In many applications, not only wireless power transmission is required, but also the system is required to have real-time communication capabilities. Functions such as output voltage feedback control, load detection, status monitoring, and multi-controller synchronization are realized.

[0003] Currently, there are usually four types of carrier modulation and demodulation technologies used in the data transmission process of wireless power transmission systems: amplitude-shift keying (ASK), frequency-shift keying (FSK), load-shift keying (LSK), and phase-shift keying (PSK). Compared with amplitude-shift keying and load-shift keying, frequency-shift keying has better anti-noise capabilities. Compared with phase-shift keying, the signal detection and recovery process of FSK is simpler, and binary frequency-shift keying (2FSK) is the simplest frequency keying modulation method. In an actual wireless power information synchronization transmission device, due to the flexibility and convenience of the device, the distance between the transmitting end and the receiving end of the system inevitably changes vertically or horizontally. The distance change directly affects the coupling coefficient between the coupling mechanisms, affects the information transmission characteristics, and increases the bit error rate. In addition, due to the weak coupling between the coils, the transmitted signal is weak at long distances, which poses high requirements on the subsequent demodulation circuit. Summary of the Invention

[0004] The present invention provides a wide-range information transmission design method based on an improved LCC compensation topology structure with dual resonant frequencies to solve problems such as weak transmission signals caused by a small coupling coefficient and increased bit error rate of information transmission caused by changes in the coupling coefficient due to distance changes in existing wireless power transmission systems.

[0005] The present invention is achieved through the following technical solutions:

[0006] A wide-range information transmission design method based on an improved LCC compensation topology structure with dual resonant frequencies, the design method comprising the following steps:

[0007] Step 1: Analyze the frequency characteristics of the existing LCC compensation topology circuit and build a magnetic communication circuit with an improved LCC compensation topology structure;

[0008] Step 2: Based on the magnetic communication circuit in Step 1, establish an equivalent circuit model of the improved magnetic communication circuit;

[0009] Step 3: Based on the equivalent circuit model in Step 2, derive the relationship between the resonant frequency f l , f0, f h and the parameters of the coupling mechanism; the relationship model is:

[0010]

[0011] where x = L dp2 / L dp1 , y = C dp2 / C dp1 , L dp2 and L dp1 are the self-inductance of the coil and the parallel compensation inductance, C dp2 and C dp1 are the series compensation capacitor and the parallel compensation capacitor;

[0012] Step 4: Analyze the transmission characteristics of the circuit at the resonant frequencies f l , f0, f h and determine the carrier frequencies f l and f h of 2FSK;

[0013] Step 5: Derive the relationship between the information transmission voltage gain G l at the low-frequency carrier f l , the information transmission voltage gain G h at the high-frequency carrier f h and the series resistance R td of the transmitting loop, the series resistance R rd of the receiving loop, the low carrier frequency f l , the high carrier frequency f h , and the mutual inductance M between the transmitting and receiving coils;

[0014] Step 6: Based on Steps 3 - 5, determine the design directions of x and y in Step 3: Select larger x and smaller y, satisfying x ≥ 10, 0 < y ≤ 1;

[0015] Step 7: Based on x and y in Step 6, derive the relationship between the equivalent inductance l of the loop at the low-frequency carrier f , the equivalent inductance h of the loop at the high-frequency carrier f and the parallel compensation inductance L dp1 , x, α, and β;

[0016] Step 8: Based on and in Step 7, derive at the low-frequency carrier fl Response time of the following information receiving circuit High-frequency carrier f h Response time of the following information receiving circuit Series resistance R with the receiving circuit rd , Circuit equivalent inductance Relationship between them;

[0017] Step 9: Based on Step 8, determine the relationship between x and y, and the relationship model is xy = y + 1;

[0018] Step 10: Based on Step 9, deduce the response time of the information transmitting circuit at the low-frequency carrier f l Response time of the following information receiving circuit High-frequency carrier f h Response time of the information transmitting circuit Series resistance R with the transmitting circuit td Series resistance R with the receiving circuit rd , Low-frequency carrier f l , Low-frequency carrier f h , Mutual inductance M between the transmitting and receiving coils, circuit equivalent inductance Relationship between them;

[0019] Step 11: Based on Step 10, determine the relationship between x and y, the design direction of f0 and M, and the relationship model is: xy = 1. Select the smaller f0, where 0 < f0 ≤ 2 MHz and 0 < M ≤ 10 μH;

[0020] Step 12: Based on the low-frequency carrier f in Step 8 and Step 10 l Response time of the information receiving circuit Response time of the information transmitting circuit And high-frequency carrier f h Response time of the information receiving circuit Response time of the information transmitting circuit t h p , Determine the series resistance R of the transmitting circuit td And series resistance R of the receiving circuit rd ;

[0021] Step 13: Analyze the transmission characteristics of the magnetic coupling communication transmission system and compare the transmission characteristics with the target value. If the target value is reached, end. If the target value is not reached, go to Step 14;

[0022] Step 14: Adjust the parameters of the magnetic coupling communication transmission system;

[0023] Step 15: Repeat the above Steps 3 to 14 until the information transmission characteristics reach the target value.

[0024] Further, the equivalent circuit model of step 2 includes the 2FSK modulation signal U d , the inductance L of the information transmitting coil dp2 , the inductance L of the information receiving coil ds2 , the parallel compensation inductance L of the information transmitting loop dp1 and the parallel compensation capacitor C dp1 , the series compensation capacitor C of the information transmitting loop dp2 , the series resistance R of the information transmitting loop td , the parallel compensation inductance L of the information receiving loop ds1 and the parallel compensation capacitor C ds1 , the series compensation capacitor C of the information receiving loop ds2 , the series resistance R of the information receiving loop rd , the extracted voltage U on the information receiving side out , the mutual inductance M between the transmitting and receiving coils, high-pass filter 0, high-pass filter 1, high-pass filter 2, power amplifier 1, power amplifier 2, envelope detector 1, envelope detector 2, low-pass filter 1, low-pass filter 2, comparator 1, comparator output resistance R 11 and modulation output zener diode D3;

[0025] The transmitting loop includes the inductance L of the information transmitting coil dp2 , the parallel compensation inductance L of the information transmitting loop dp1 , the parallel compensation capacitor C of the information transmitting loop dp1 , the series compensation capacitor C of the information transmitting loop dp2 and the series resistance R of the information transmitting loop td ;

[0026] The receiving loop includes the inductance L of the information receiving coil ds2 , the parallel compensation inductance L of the information receiving loop ds1 , the parallel compensation capacitor C of the information receiving loop ds1 and the series compensation capacitor C of the information transmitting loop ds2 ;

[0027] The transmitting loop and the receiving loop have the same structure.

[0028] Further, the high-pass filter 0 includes a capacitor C0, a resistor R0 and an inductor L0, which are used to filter out low-frequency noise interference;

[0029] The high-pass filter 1 includes a capacitor C1, a resistor R1 and an inductor L1, which are used to filter out the carrier signal with a frequency of f l ;

[0030] The high-pass filter 2 includes a capacitor C2, a resistor R2 and an inductor L2, which are used to filter out the carrier signal with a frequency of f h ;

[0031] The power amplifiers 1 and 2 respectively amplify the carrier signals with frequencies of f h and f l output from the high-pass filters 1 and 2;

[0032] The envelope detector 1 includes a diode D1, a capacitor C3 and a resistor R7, and detects the signal output from the high-pass filter 1;

[0033] The envelope detector 2 includes a diode D2, a capacitor C4 and a resistor R8, and detects the signal output from the high-pass filter 2;

[0034] The low-pass filter 1 includes a resistor R9 and a capacitor C5, and shapes the signal output from the envelope detector 1;

[0035] The low-pass filter 2 includes a resistor R 10 and a capacitor C6, and shapes the signal output from the envelope detector 2;

[0036] The comparator performs a comparison operation on the signals output from the low-pass filter 1 and the low-pass filter 2, restores the information signal, and U dout is the demodulation output signal.

[0037] Further, the relational model of step 5 is:

[0038]

[0039] where ω l and ω h are the angular frequencies corresponding to f l and f h , and the relationship is ω l = 2πf l , ω h = 2πf h .

[0040] Further, the relational model of step 7 is:

[0041]

[0042] where z = p represents the information transmitting loop, and z = s represents the information receiving loop.

[0043] Further, the relational model of step 8 is:

[0044]

[0045] Further, the relational model of step 10 is:

[0046]

[0047] The beneficial effects of the present invention are as follows:

[0048] Based on the improved LCC compensation topology structure, the reflection impedance is located on the main loop composed of L dp2 in series with C dp , and the influence on the resonant frequency point of the transmitting loop is ensured, and the consistency of the resonant frequency design of the transmitting loop and the receiving loop is guaranteed.

[0049] Compared with the existing 2FSK modulation method, the present invention uses the system resonant frequency for signal transmission, improving the signal strength.

[0050] The present invention ensures the consistency of the loop response time and signal strength under different carrier frequencies when the coupling coefficient changes, reduces the bit error rate and the design difficulty of the demodulation circuit, and effectively improves the system design and optimization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Att Figure 1 is the flowchart of the method of the present invention.

[0052] Att Figure 2 is the equivalent circuit model diagram of the magnetic communication circuit of the present invention.

[0053] Att Figure 3 is the schematic diagram of the relationship between the resonant frequency of the present invention and x, y when ω0 = 2πf0.

[0054] Att Figure 4 is the schematic diagram of the relationship between the ratio of the response times of the transmitting loop at high and low carrier frequencies of the present invention and f0 and M.

[0055] Att Figure 5 is the schematic diagram of the relationship between the ratio of the response time of the transmitting loop to the response time of the receiving loop and the series resistance R td of the transmitting loop and the series resistance R rd of the receiving loop of the present invention under different carrier frequencies.

[0056] Att Figure 6 is the voltage waveform provided by the present invention, where (a) is the original signal and the modulation signal U d ; (b) is the voltage U out extracted on the information receiving side and the demodulation output signal U dout when the transmission distance is 50 mm; (c) is the voltage U out extracted on the information receiving side and the demodulation output signal U dout when the transmission distance is 100 mm. DETAILED DESCRIPTION OF THE INVENTION

[0057] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0058] A wide-range information transmission design method based on an improved LCC compensation topology structure with dual resonance frequency points, the design method comprising the following steps:

[0059] Step 1: Analyze the frequency characteristics of the existing LCC compensation topology circuit, and build a magnetic communication circuit with an improved LCC compensation topology structure;

[0060] Step 2: Based on the magnetic communication circuit in Step 1, establish an equivalent circuit model of the improved magnetic communication circuit;

[0061] Step 3: Based on the equivalent circuit model in Step 2, derive the relationship between the resonance frequencies f l , f0, f h and the parameters of the coupling mechanism; the relationship model is:

[0062]

[0063] where x = L dp2 / L dp1 , y = C dp2 / C dp1 , L dp2 and L dp1 are the self-inductance of the coil and the parallel compensation inductance, C dp2 and C dp1 are the series compensation capacitor and the parallel compensation capacitor;

[0064] Step 4: Analyze the transmission characteristics of the circuit at the resonance frequencies f l , f0, f h , and determine the carrier frequencies f l and f h of 2FSK;

[0065] Step 5: Derive the relationship between the information transmission voltage gain G l at the low-frequency carrier f l , the information transmission voltage gain G h at the high-frequency carrier f h , the series resistance R td of the transmitting loop, the series resistance R rd of the receiving loop, the low carrier frequency f l , the high carrier frequency f h , and the mutual inductance M between the transmitting and receiving coils;

[0066] Step 6: Based on Steps 3 - 5, determine the design directions of x and y in Step 3: Select the larger x and the smaller y, where x ≥ 10 and 0 < y ≤ 1;

[0067] Step 7: Based on x and y in Step 6, derive the equivalent inductance of the loop l at the low - frequency carrier f and the equivalent inductance of the loop h at the high - frequency carrier f and the relationship between the parallel - compensation inductor L dp1 , x, α, and β;

[0068] Step 8: Based on and derived in Step 7, derive the response time of the information - receiving loop l at the low - frequency carrier f and the response time of the information - receiving loop h at the high - frequency carrier f and the relationship between the series resistance R rd of the receiving loop, the equivalent inductance of the loop ;

[0069] Step 9: Based on Step 8, determine the relationship between x and y, and the relationship model is xy = y + 1;

[0070] Step 10: Based on Step 9, derive the response time of the information - transmitting loop l at the low - frequency carrier f and the response time of the information - transmitting loop h at the high - frequency carrier f and the relationship between the series resistance R td of the transmitting loop, the series resistance R rd of the receiving loop, the low - frequency carrier f l , the low - frequency carrier f h , the mutual inductance M between the transmitting and receiving coils, and the equivalent inductance of the loop ;

[0071] Step 11: Based on Step 10, determine the relationship between x and y, and the design directions of f0 and M. The relationship model is: xy = 1. Select the smaller f0, where 0 < f0 ≤ 2 MHz and 0 < M ≤ 10 μH;

[0072] Step 12: Based on the response time of the information - receiving loop l at the low - frequency carrier f in Steps 8 and 10 and the response time of the information - transmitting loop and the response time of the information - receiving loop h at the high - frequency carrier f Response time of information transmission loop Determine the series resistance R of the transmission loop td and the series resistance R of the receiving loop rd ; Step 13: Analyze the transmission characteristics of the magnetic coupling communication transmission system, and compare the transmission characteristics with the target value. If the target value is reached, end. If the target value is not reached, go to Step 14;

[0073] Step 14: Adjust the parameters of the magnetic coupling communication transmission system;

[0074] Step 15: Repeat the above steps 3 to 14 until the information transmission characteristics reach the target value.

[0075] Furthermore, the equivalent circuit model of Step 2 includes the 2FSK modulation signal U d , the inductance L of the information transmitting coil dp2 , the inductance L of the information receiving coil ds2 , the parallel compensation inductance L of the information transmission loop dp1 and the parallel compensation capacitor C dp1 , the series compensation capacitor C of the information transmission loop dp2 , the series resistance R of the information transmission loop td , the parallel compensation inductance L of the information receiving loop ds1 and the parallel compensation capacitor C ds1 , the series compensation capacitor C of the information receiving loop ds2 , the series resistance R of the information receiving loop rd , the extracted voltage U on the information receiving side out , the mutual inductance M between the transmitting and receiving coils, high-pass filter 0, high-pass filter 1, high-pass filter 2, power amplifier 1, power amplifier 2, envelope detector 1, envelope detector 2, low-pass filter 1, low-pass filter 2, comparator 1, comparator output resistance R 11 and modulation output voltage stabilizing diode D3;

[0076] The transmission loop includes the inductance L of the information transmitting coil dp2 , the parallel compensation inductance L of the information transmission loop dp1 , the parallel compensation capacitor C of the information transmission loop dp1 , the series compensation capacitor C of the information transmission loop dp2 and the series resistance R of the information transmission loop td ;

[0077] The receiving loop includes the inductance L of the information receiving coil ds2 , the parallel compensation inductance L of the information receiving loop ds1 , the parallel compensation capacitor C of the information receiving loop ds1 and the series compensation capacitor C of the information transmission loop ds2 ;

[0078] The transmitting circuit and the receiving circuit have the same structure.

[0079] Furthermore, the high-pass filter 0 includes a capacitor C0, a resistor R0, and an inductor L0, which are used to filter out low-frequency noise interference, such as 85 kHz noise from the energy;

[0080] The high-pass filter 1 includes a capacitor C1, a resistor R1, and an inductor L1, which are used to filter out the carrier signal with a frequency of f l ;

[0081] The high-pass filter 2 includes a capacitor C2, a resistor R2, and an inductor L2, which are used to filter out the carrier signal with a frequency of f h ;

[0082] The power amplifier 1 and the power amplifier respectively amplify the carrier signals with frequencies of f h and f l output by the high-pass filter 1 and the high-pass filter 2;

[0083] The envelope detector 1 includes a diode D1, a capacitor C3, and a resistor R7, which detect the signal output by the high-pass filter 1;

[0084] The envelope detector 2 includes a diode D2, a capacitor C4, and a resistor R8, which detect the signal output by the high-pass filter 2;

[0085] The low-pass filter 1 includes a resistor R9 and a capacitor C5, which shape the signal output by the envelope detector 1;

[0086] The low-pass filter 2 includes a resistor R 10 and a capacitor C6, which shape the signal output by the envelope detector 2;

[0087] The comparator performs a comparison operation on the signals output by the low-pass filter 1 and the low-pass filter 2 to recover the information signal, and U dout is the demodulation output signal.

[0088] In step 3, the transmitting circuit and the receiving circuit are symmetric. Taking the transmitting side as an example, when the operating frequency is ω, the input impedance of the circuit seen from the U d port is

[0089]

[0090] At resonance, Z = 0 or ∞, and the resonant frequency of the transmitting circuit is obtained as

[0091]

[0092] where x = L dp2 / L dp1, y = C dp2 / C dp1 , f0 is the parallel resonance frequency point, f l and f h are the low-frequency series resonance frequency point and the high-frequency series resonance frequency point respectively.

[0093] In the above step 4, when the transmitting loop and the receiving loop resonate at the series resonance points f l and f h , the system has the series resonance frequency characteristic and the loop current reaches the maximum. Under the same mutual inductance, the receiving loop has the maximum induced voltage, which is beneficial to information transmission. Select the series resonance points f l and f h as the carrier frequencies of 2FSK.

[0094] In the above step 5, according to Kirchhoff's voltage law, the main loop currents i l and f h in the transmitting loop and the receiving loop at the series resonance frequencies f Lp2 and the main loop current i Ls2 are:

[0095]

[0096] Among them, when j = l, ω l = 2πf l ; when j = h, ω h = 2πf h .

[0097] At high and low carrier frequencies, the voltage extracted on the information receiving side is U out

[0098] ω = ω l , ω h (4)

[0099] The information transmission voltage gain is

[0100]

[0101] To ensure that the system is not restricted by the type of transmitted signal, try to ensure that the circuit parameters are the same and the output voltage amplitude is the same at different frequencies. It can be seen from Equation (5) that the output voltage amplitude is only related to the frequency, so two carrier signals with similar frequencies should be used.

[0102] Please refer to Figure 3 , in the above step 6, the relationship between the high and low resonance frequencies and x, y is as Figure 3 shown, where ω0 = 2πf0. It can be seen that: increasing x, increasing y, ω h tends to ω0; decreasing x, decreasing y, ω lTends to ω0. To make ω l close to ω h it is necessary to select a larger x value and a smaller y value.

[0103] Please refer to Figure 2 , in the above step 7, according to the definition of the circuit quality factor, when improving the working frequency of the LCC compensation topology circuit to ω, the quality factor is

[0104] Q = ωE stored_max / P loss (6)

[0105] where E stored_max is the maximum energy storage of the resonant circuit in one cycle, and P loss is the power consumption of the resonant circuit in one cycle. Figure 2 In

[0106]

[0107] where I Ldp1 and I Ldp2 are the effective values of the currents i Ldp1 and i Ldp2 ; u Cdp1 and u Cdp2 are the voltages across the parallel compensation capacitor C dp1 and the series compensation capacitor C dp2 .

[0108] Figure 2 In

[0109] the power consumption of the improved LCC compensation topology circuit is loss P Ldp2 2 = I td (8)

[0110] According to Kirchhoff's voltage law, we can get:

[0111]

[0112] Combining (2), (6)-(9), we can get:

[0113]

[0114] Therefore, the equivalent inductance of the loop at the low-frequency carrier f l and the equivalent inductance of the loop at the high-frequency carrier f h are:

[0115] ​​

[0116] Among them, when z = p, it represents the information transmitting circuit, and when z = s, it represents the information receiving circuit.

[0117] In step 8, according to the definition of the loop response time, the low-frequency carrier f l Response time of the information receiving circuit below High-frequency carrier f h Response time of the information receiving circuit below Is

[0118]

[0119] In step 9, by combining (11) and (13), we can obtain: The ratio of the response time of the high-frequency f h Of the receiving circuit to the response time of the low-frequency f l Is:

[0120]

[0121] To ensure the consistency of the information transmission rate at different carrier frequencies, let the above formula = 1, and the relationship model between x and y is xy = y + 1.

[0122] In step 10, the reflected impedance Z l Of the receiving circuit at the low-frequency carrier f l_ref And the reflected impedance Z h Of the receiving circuit at the high-frequency carrier f h_ref Are:

[0123]

[0124] According to the definition of the loop response time, the response time l Of the information transmitting circuit at the low-frequency carrier f High-frequency carrier f h Response time of the information transmitting circuit below Is

[0125]

[0126] In step 11, by combining (14) and (15), we can obtain: The ratio of the response time of the high-frequency f h Of the transmitting circuit to the response time of the low-frequency f l Is:

[0127]

[0128] To ensure the consistency of the information transmission rate at different carrier frequencies, combining the analysis in step 9 above and letting the above formula (16) = 1, we get: The relationship model between x and y is xy = 1.

[0129] In addition, please refer to Figure 4, affected by the reflected impedance, the response time of the transmitting loop is related not only to the values of x and y, but also to the frequency f0 and M. From Figure 4 it can be obtained that: by reducing f0 and M, lg(t h / t l ) tends to 0. To obtain similar t h and t l , smaller f0 and M should be selected.

[0130] In step 12, please refer to Figure 5 . At two carrier frequencies, the ratio of the response time of the transmitting loop to that of the receiving loop, lg(t p / t s ), shows the same law. As the series resistance R rd of the receiving loop increases, the difference in the response time of the transmitting and receiving loops first decreases and then increases; due to the difference between high and low frequencies, lg(t l p / t l s ) is always greater than lg(t h p / t h s ) at high frequencies. The consistency of the response time of the transmitting and receiving loops can be achieved by adjusting the loop impedance.

[0131] In step 13, the analysis of the transmission characteristics of the magnetic coupling communication transmission system includes calculating the system information transmission rate and the information transmission voltage gain.

[0132] Among them, the information transmission voltage gain under different carriers is calculated by equation (5). The calculation formula for the system transmission rate is equation (17 as

[0133]

[0134] where

[0135] In step 14, the adjustment of the parameters of the magnetic coupling communication transmission system includes adjusting the self-inductances L dp2 and L ds2 of the information transmitting coil and the information receiving coil, the ratio x of the self-inductance L dp2 of the transmitting coil to the parallel compensation inductor L dp1 , the ratio y of the series compensation capacitor C dp2 of the information transmitting coil to the parallel compensation capacitor C dp1 , the parallel resonance frequency point f0, the series resistance R td of the information transmitting loop, and the series resistance R rd of the information receiving loop.

[0136] In step 15, the number of times of repeating the above steps 3 to 15 can be selected as needed. It can be understood that simultaneously repeating the above steps 3 to 15 can optimize the magnetic coupling communication transmission system.

[0137] Compared with the existing LCC compensation topology structure, this method is based on an improved LCC compensation topology structure, and the reflected impedance is located on the main loop composed of L dp2 and C dp in series, which affects the resonant frequency point of the transmitting loop and ensures the consistency of the resonant frequency design of the transmitting loop and the receiving loop. Compared with the existing 2FSK modulation method, using the system resonant frequency for signal transmission improves the signal strength. The wide-range information transmission design method based on the improved LCC compensation topology structure with double resonant frequency points adopted in the present invention ensures the consistency of the loop response time and signal strength at different carrier frequencies when the coupling coefficient changes, reduces the bit error rate and the design difficulty of the demodulation circuit, and effectively improves the system design and optimization efficiency. The magnetic communication system parameters determined by the above design method are shown in Table 1. When the transmission distance is 50 mm and 100 mm, the original information, the modulation signal U d , the voltage U out extracted on the information receiving side, and the demodulation output signal U dout waveforms are as Figure 6 shown. It can be seen that when the transmission distance changes by 100%, the extracted voltages at different carrier frequencies on the receiving side are the same, and the information can be correctly demodulated and output, and the bit error rate is 0. This further verifies the effectiveness of this design method.

[0138] Table 1 Design parameters of the coupling mechanism

[0139]

Claims

1. A wide - range information transmission design method based on an improved LCC compensation topology structure with double resonance frequencies, characterized in that, The described design method includes the following steps: Step 1: Analyze the frequency characteristics of the existing LCC compensation topology circuit, and build a magnetic communication circuit with an improved LCC compensation topology structure; Step 2: Based on the magnetic communication circuit in Step 1, establish an equivalent circuit model of the improved magnetic communication circuit; Step 3: Based on the equivalent circuit model in Step 2, derive the resonant frequency f of the information emission loop l , f0, f h and the relationship with the parameters of the coupling mechanism; the relationship model is as follows: where x = L dp2 / L dp1 , y = C dp2 / C dp1 , L dp2 and L dp1 are the self - inductance of the information - transmitting coil and the parallel - compensation inductance, C dp2 and C dp1 are the series - compensation capacitor and the parallel - compensation capacitor; Step 4: Analyze the transmission characteristics of the circuit at the resonant frequencies f l , f0, f h to determine the carrier frequencies f l and f h ; Step 5: Deduce the relationship model among the information transmission voltage gain G l at the low-frequency carrier f l , the information transmission voltage gain G h at the high-frequency carrier f h , the series resistance R td of the transmitting loop, the series resistance R rd of the receiving loop, the low carrier frequency f l , the high carrier frequency f h , and the mutual inductance M between the transmitting and receiving coils; Step 6: Based on Steps 3 - 5, determine the design directions of x and y in Step 3: Select a larger x and a smaller y, satisfying x≥10, 0<y≤1; Step 7: Based on x and y in Step 6, derive the equivalent inductance of the loop at low-frequency carrier f l under the condition high-frequency carrier f h under the condition and the relationship model between the equivalent inductance of the loop and the shunt compensation inductor L dp1 , x, α, and β; Step 8: Based on and deduce the response time of the information receiving circuit at low-frequency carrier f l and the response time of the information receiving circuit at high-frequency carrier f and the relationship model between the series resistance R h of the receiving circuit and the equivalent inductance of the loop; rd ​​ Step 9: Based on Step 8, determine the relationship model between x and y. The relationship model is xy = y + 1; Step 10: Based on Step 9, deduce the response time of the information transmission loop at the low-frequency carrier f l and the response time of the information transmission loop at the high-frequency carrier f as well as the relationship model between the series resistance R h of the transmission loop, the series resistance R of the receiving loop, the low-frequency carrier f td , the high-frequency carrier f rd , the mutual inductance M between the transceiver coils, and the equivalent inductance l of the loop; h ​​ Step 11: Based on Step 10, determine the relationship between x and y, and the design directions of f0 and M. The relationship model is: xy = 1. Select a smaller f0, where 0<f0≤2MHz, 0<M≤10μH; Step 12: Based on the low-frequency carrier f in Steps 8 and 10 l Response time of the information receiving circuit Response time of the information transmitting circuit and the high-frequency carrier f h Response time of the information receiving circuit Response time of the information transmitting circuit Determine the series resistance R of the transmitting circuit td and the series resistance R of the receiving circuit rd ; Step 13: Analyze the transmission characteristics of the magnetic coupling communication transmission system, and compare the transmission characteristics with the target value. If the target value is reached, end. If the target value is not reached, enter Step 14; Step 14: Adjust the parameters of the magnetic coupling communication transmission system; Step 15: Repeat the above Steps 3 to 14 until the information transmission characteristics reach the target value.

2. The design method for wide - range information transmission based on an improved LCC compensation topology with double resonance frequencies according to claim 1, characterized in that, The equivalent circuit model of the said step 2 includes the 2FSK modulation signal U d , the inductance L of the information transmitting coil dp2 , the inductance L of the information receiving coil ds2 , the parallel compensation inductance L of the information transmitting loop dp1 and the parallel compensation capacitor C dp1 , the series compensation capacitor C of the information transmitting loop dp2 , the series resistance R of the information transmitting loop td , the parallel compensation inductance L of the information receiving loop ds1 and the parallel compensation capacitor C ds1 , the series compensation capacitor C of the information receiving loop ds2 , the series resistance R of the information receiving loop rd , the extracted voltage U on the information receiving side out , the mutual inductance M between the transmitting and receiving coils, high-pass filter 0, high-pass filter 1, high-pass filter 2, power amplifier 1, power amplifier 2, envelope detector 1, envelope detector 2, low-pass filter 1, low-pass filter 2, comparator 1, the comparator output resistance R 11 and the modulation output voltage stabilizing diode D3; The transmitting circuit includes the information transmitting coil inductance L dp2 , the parallel compensation inductance L of the information transmitting circuit dp1 , the parallel compensation capacitor C of the information transmitting circuit dp1 , the series compensation capacitor C of the information transmitting circuit dp2 and the series resistance R of the information transmitting circuit td ; The receiving circuit includes an information receiving coil inductor L ds2 , a parallel compensation inductor L for the information receiving circuit ds1 , a parallel compensation capacitor C for the information receiving circuit ds1 and a series compensation capacitor C for the information receiving circuit ds2 ; The structures of the transmitting loop and the receiving loop are the same.

3. The design method for wide - range information transmission based on an improved LCC compensation topology structure with double resonance frequency points according to claim 2, characterized in that, The high-pass filter 0 includes a capacitor C0, a resistor R0, and an inductor L0, which are used to filter out low-frequency noise interference; The high-pass filter 1 includes a capacitor C1, a resistor R1, and an inductor L1, which are used to filter out a carrier signal with a frequency of f l ; The high-pass filter 2 includes a capacitor C2, a resistor R2, and an inductor L2, and is used to filter out a carrier signal with a frequency of f h ; The power amplifier 1 and the power amplifier 2 respectively amplify the carrier signals with frequencies of f h and f l output by the high-pass filter 1 and the high-pass filter 2; The envelope detector 1 includes a diode D1, a capacitor C3, and a resistor R7, which perform envelope detection on the signal output by the high-pass filter 1; The envelope detector 2 includes a diode D2, a capacitor C4, and a resistor R8, which perform envelope detection on the signal output by the high-pass filter 2; The low-pass filter 1 includes a resistor R9 and a capacitor C5, which shape the signal output by the envelope detector 1; The low-pass filter 2 includes a resistor R 10 and a capacitor C6 to shape the signal output from the envelope detection 2; The comparator 1 performs a comparison operation on the signals output by the low-pass filter 1 and the low-pass filter 2 to recover the information signal, U dout is the demodulated output signal.

4. A wide-range information transmission design method based on an improved LCC compensation topology structure with double resonance frequency points according to claim 1, characterized in that The relationship model of Step 5 is: where, ω l and ω h are the angular frequencies corresponding to f l and f h , and the relationship is ω l = 2πf l , ω h = 2πf h .

5. A wide-range information transmission design method based on an improved LCC compensation topology with double resonance frequency points according to claim 1, characterized in that, The relationship model of Step 7 is: Among them, when z = p, it represents the information transmitting loop, and when z = s, it represents the information receiving loop.

6. The design method for wide - range information transmission based on an improved LCC compensation topology with dual - resonant frequencies according to claim 1, wherein The relationship model of Step 8 is:

7. The design method for wide - range information transmission based on an improved LCC compensation topology with dual - resonant frequencies according to claim 4, wherein The relationship model of Step 10 is:

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