Full duplex wireless electric energy and data transmission system based on DDQ coil

Abstract

The invention provides a full duplex wireless electric energy and data transmission system based on DDQ coils, energy coils are a pair of Q-type coils, and data coils are a pair of DD coils. Wherein the two ends of the primary side signal coil are connected in parallel with a primary side data transmitting branch formed by connecting a primary side signal source and a first transmitting wave-blocking network in series and a primary side data receiving branch formed by connecting a primary side sampling resistor and a first receiving wave-blocking network in series; the two ends of the secondary side signal coil are connected in parallel with a secondary side data transmitting branch formed by connecting a secondary side signal source and a second transmitting wave-blocking network in series and a secondary side data receiving branch formed by connecting a secondary side sampling resistor and a second receiving wave-blocking network in series. The beneficial effects are that the DDQ coil structure is employed, the two channels can be mutually independent, in addition, the wave blocking network in the data transmission channel employs a two-resonance one-rejection structure, signal emission and signal reception at the same side directly share a signal coil, couplers and independent series capacitors are reduced, and the circuit structure is simplified.

Description

Technical Field

[0001] The invention relates to the field of wireless power transmission, in particular to a full-duplex wireless power and data transmission system based on a DDQ coil. Background Art

[0002] Wireless Power Transfer (WPT) technology is now applied to many fields, such as electric vehicles, mobile phones, sensors, medical equipment, etc. This technology is booming due to its advantages such as high efficiency, flexibility, and stability. In the application of WPT technology, energy feedback control, system status monitoring, battery SOC information upload, load and foreign object detection all inevitably require data transmission between the transmitter and the receiver, so the research on energy signal parallel transmission technology has gradually attracted attention. With the increasing demand for full-duplex communication, such as wireless charging of mobile robots, wireless charging of mobile phones, dynamic wireless power supply of electric vehicles, etc., one-way signal transmission is difficult to meet the communication needs of the system, so the signal transmission system with full-duplex communication capability has become a hot topic of current research.

[0003] Traditional signal transmission technologies include NFC technology, Bluetooth module, RFID, Wi-Fi module, ZigBee, etc. However, there are some problems with the application of these mature communication modules in WPT systems: Bluetooth, ZigBee, WiFi and other communication establishment time is long, and there are also stability issues in the information interaction process; on the other hand, these modules are close to the frequency band of many radio frequency communication devices (IEEE802.11), which are easy to interfere with each other. Even in some occasions (such as underwater environments in the ocean), these communication methods are difficult to be practical. Therefore, as a WPT system energy signal parallel transmission technology that can quickly, stably and reliably realize signal transmission, it has attracted great attention.

[0004] Some people have also proposed a system for simultaneous signal transmission based on the WPT energy transmission channel. Currently, there are two main implementation methods, energy modulation method and independent carrier method. The energy modulation method mainly realizes signal modulation by changing parameters such as the amplitude, frequency and phase of the energy wave. However, the energy modulation method has the problem of energy fluctuation, and the signal modulation process will cause unstable energy transmission. The independent carrier method uses an independent carrier with a frequency far higher than the energy resonance frequency for signal modulation. Since there are energy waves and signal modulation waves on the energy coupling coil, the energy channel and the signal channel affect each other at the two frequencies. Therefore, the key to the independent carrier method lies in the injection and separation of the signal modulation wave. Compared with energy modulation, the independent carrier method can achieve stable energy transmission, but the signal transmission is extremely susceptible to interference from energy harmonics and external noise, which can easily lead to signal transmission failure.

[0005] Chinese patent CN111969731A also discloses a full-duplex WPT energy signal parallel transmission system based on double-sided LCC, which uses an LC wave-blocking network to avoid the influence between the energy channel and the signal channel. However, since the energy coil and the signal coil are shared, the cross-connection of components between the two channels is likely to change the inherent resonant frequency of the circuit, thereby affecting the transmission efficiency. At the same time, the series connection of capacitors and coupler structures on the outside of the wave-blocking network also increases the complexity of the circuit. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a full-duplex wireless power and data transmission system based on DDQ coils, which further simplifies the circuit structure on the basis of the existing full-duplex WPT energy signal parallel transmission system, and meets the energy and data transmission requirements through parameter configuration.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A full-duplex wireless energy and data transmission system based on DDQ coils, comprising an energy transmission channel and a data transmission channel, wherein the key is that: the coupling coil in the energy transmission channel is a pair of Q-type coils, and the coupling coil in the data transmission channel is a pair of DD coils, wherein: the two ends of the primary signal coil are connected in parallel with a primary data transmission branch formed by a primary signal source and a first transmitting wave-blocking network in series, and a primary data receiving branch formed by a primary sampling resistor and a first receiving wave-blocking network in series, and the two ends of the secondary signal coil are connected in parallel with a secondary data transmission branch formed by a secondary signal source and a second transmitting wave-blocking network in series, and a secondary data receiving branch formed by a secondary sampling resistor and a first receiving wave-blocking network in series. A secondary data receiving branch is formed by connecting a sample resistor in series with a second receiving choke network, wherein the first transmitting choke network, the first receiving choke network, the second transmitting choke network and the second receiving choke network all adopt a two-resonance-one-rejection structure formed by an LCC parallel network, wherein: the carrier frequency of the primary signal source is used as the resonant frequency of the first transmitting choke network and the second receiving choke network, and the rejection frequency of the first receiving choke network and the second transmitting choke network; the carrier frequency of the secondary signal source is used as the resonant frequency of the second transmitting choke network and the first receiving choke network, and the rejection frequency of the second receiving choke network and the first transmitting choke network.

[0009] Optionally, the energy transmission channel includes a direct current power supply, a high-frequency inverter, a primary resonant network, an energy coupling coil, a secondary resonant network, a rectifier filter and an electrical load.

[0010] Optionally, both the primary resonant network and the secondary resonant network adopt LCC compensation networks.

[0011] Optionally, the operating frequency of the energy transmission channel is 85 kHz, the carrier frequency of the primary signal source is 4 MHz, and the carrier frequency of the secondary signal source is 6 MHz.

[0012] Optionally, the coupling coil in the energy transmission channel and the coupling coil in the data transmission channel are overlapped in the same direction, and the DD coil is covered by the Q-type coil.

[0013] Optionally, the first transmitting wave-blocking network includes an inductor L dt1 and capacitor C dt1 The series branch formed and the capacitor C connected in parallel to the series branch dtp , and satisfies

[0014] The first receiving wave blocking network includes an inductor L dr1 and capacitor C dr1 The series branch formed and the capacitor C connected in parallel to the series branch drp , and satisfies

[0015] The second transmitting wave blocking network includes an inductor L dt2 and capacitor C dt2 The series branch formed and the capacitor C connected in parallel to the series branch dts , and satisfies

[0016] The second receiving wave blocking network includes an inductor L dr2 and capacitor C dr2 The series branch formed and the capacitor C connected in parallel to the series branch drs , and satisfies

[0017] w1 is the carrier angular frequency of the primary signal source, and w2 is the carrier angular frequency of the secondary signal source.

[0018] Optionally, the primary signal coil L dp = Secondary signal coil L ds , inductance L dt1 = Inductance L dr2 , capacitor C dt1 =Capacitance C dr2 , capacitor C dtp =Capacitance C drs , inductance L dr1 = Inductance L dt2 , capacitor C dr1 =Capacitance C dt2 , capacitor C drp =Capacitance C dts .

[0019] Optionally, the components in the data transmission channel meet the following requirements:

[0020]

[0021]

[0022] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0023] The present invention adopts a DDQ coil structure, so that the energy transmission channel and the data transmission channel circuit connection can be independent of each other. The cross coupling between the energy coil and the data coil is theoretically 0, and there will be no cross coupling in the magnetic field between the coils. At the same time, the impedance characteristics of the circuit will not be changed due to the introduction of accessory components between the channels. In addition, the data transmission channel adopts a two-resonance and one-rejection structure composed of an LCC parallel network. The signal transmission and signal reception on the same side can directly share the signal coil, reducing the coupler and independent series capacitors, simplifying the circuit structure, and through a new parameter configuration, it can meet the synchronous transmission of energy and data. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings of the present invention are as follows.

[0025] Figure 1 This is a circuit schematic diagram of a full-duplex wireless power and data transmission system based on a DDQ coil provided by the present invention.

[0026] Figure 2 This is a schematic diagram of the DDQ coil structure in a specific embodiment of the present invention;

[0027] Figure 3 It is a structural diagram of a two-resonance-one-rejection circuit composed of an LCC parallel network in a specific embodiment of the present invention;

[0028] Figure 4 for Figure 3 The impedance characteristic diagram of the two resonance and one rejection circuit structure is shown;

[0029] Figure 5 This is a circuit structure diagram of a full-duplex communication data transmission channel in a specific embodiment of the present invention;

[0030] Figure 6 The circuit and impedance characteristics of the primary side of the forward data transmission in the specific embodiment of the present invention;

[0031] Figure 7 The circuit and impedance characteristics of the primary side of reverse data transmission in the specific embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] like Figure 1 and Figure 2 As shown in FIG. 1 , a full-duplex wireless power and data transmission system based on a DDQ coil includes an energy transmission channel and a data transmission channel. The two channels are separated from each other, the upper one is the energy transmission channel, and the lower one is the data transmission channel. The energy transmission channel is powered by a DC power supply E dc , a full-bridge inverter consisting of four MOSFETs (S1-S4), an LCC compensation topology, a coupling coil, a rectifier filter and a load. The data transmission channel consists of a signal source, a transmitting circuit and a receiving circuit. The energy transmission channel is unidirectional. Uin and Iin are the output voltage and output current after inversion respectively. At the same time, U RL and I RL are the voltage and current on the load respectively. L The equivalent load resistance when charging the system. C o is the secondary DC filter capacitor. The four power electronic switches S1-S4 form the primary side full-bridge inverter. The four diodes D1-D4 form the secondary side full-bridge rectifier. U rec and I rec are the input voltage and input current respectively. fp (L fs ) is the primary (secondary) side compensation inductor. C fp (C fs ) is the primary (secondary) side parallel compensation capacitor, C p (C s ) is the primary (secondary) side series compensation capacitor, forming an LCC / LCC compensation network.

[0034] In this embodiment, the energy coil and the signal coil adopt a DDQ structure, the energy coil is a pair of Q coils, and the signal coil is a pair of DD coils, so as to achieve decoupling of the signal coil and the energy coil. Figure 2 As shown, the coupling coil in the energy transmission channel and the coupling coil in the data transmission channel are arranged in the same direction, and the DD coil is covered by the Q-type coil. The DD coil and the Q coil are decoupled, and the cross-coupling coefficient between the energy channel and the data channel is theoretically 0. In principle, the frequency of the data carrier needs to be lower than the self-resonant frequency of the coil in order to effectively transmit data. A data coil with a high self-resonant frequency can be injected with a high-frequency data carrier to obtain a faster communication rate.

[0035] To ensure full-duplex data transmission, combine Figure 1It can also be seen that: the two ends of the primary signal coil are connected in parallel with a primary data transmission branch formed by the primary signal source and the first transmitting wave blocking network in series, and a primary data receiving branch formed by the primary sampling resistor and the first receiving wave blocking network in series. The two ends of the secondary signal coil are connected in parallel with a secondary data transmission branch formed by the secondary signal source and the second transmitting wave blocking network in series, and a secondary data receiving branch formed by the secondary sampling resistor and the second receiving wave blocking network in series. The first transmitting wave blocking network, the first receiving wave blocking network, the second transmitting wave blocking network, and the second receiving wave blocking network all adopt a two-resonance and one-rejection structure composed of an LCC parallel network, wherein: the carrier frequency of the primary signal source is used as the resonant frequency of the first transmitting wave blocking network and the second receiving wave blocking network, and the rejection frequency of the first receiving wave blocking network and the second transmitting wave blocking network; the carrier frequency of the secondary signal source is used as the resonant frequency of the second transmitting wave blocking network and the first receiving wave blocking network, and the rejection frequency of the second receiving wave blocking network and the first transmitting wave blocking network.

[0036] In order to further understand the two-resonance-one-rejection structure of the LCC parallel network, combined with Figure 3 and Figure 4 It can be seen that the two parallel networks on the same side of the data transmission channel (i.e., L p1 , C p1 , C p2 and L r1 , C r1 , C r2 ) and a serial signal coil (ie L s1 ),where L p1 , C p1 , C p2 and L r1 , C r1 , C r2 Satisfy C p1 +C p2 -w2 2 L p1 C p1 C p2 =0, C r1 +C r2 -w1 2 L r1 C r1 C r2 =0 and ω2>ω1. In order to transmit two data carriers simultaneously and reduce the interference of the data source on the same side, the two resonance points of the structure need to be designed to be the same as its two rejection points. This means that one of the resonance points of one branch is exactly the non-zero rejection point of the other branch.

[0037] Figure 5 The topology of the full-duplex communication channel used in this embodiment is shown, which consists of four LCC parallel networks (i.e., Ldt1 , C dt1 and C dtp , L dr1 , C dr1 and C drp , L dt2 , C dt2 and C dts and L dr2 , C dr2 and C drs ) consists of two signal coils (i.e. L dp and L ds ), two sampling resistors (i.e. R1 and R2) and two AC signal sources (i.e. U sig1 and U sig2 ), U sig1 and U sig2 The angular frequencies are ω1 and ω2 respectively. In a specific implementation, the operating frequency of the energy transmission channel is 85 kHz, the carrier frequency of the primary signal source is 4 MHz, and the carrier frequency of the secondary signal source is 6 MHz.

[0038] L dt1 , C dt1 , C dtp and L dr1 , C dr1 , C drp Satisfy C dt1 +C dtp -w2 2 L dt1 C dt1 C dtp =0,

[0039] C dr1 +C drp -w1 2 L dr1 C dr1 C drp =0. dp and L ds are the self-inductance of the signal primary coil and the secondary coil respectively. In order to simplify the analysis, the primary signal coil L is set in this example. dp = Secondary signal coil L ds , inductance L dt1 = Inductance L dr2 , capacitor C dt1 =Capacitance C dr2 , capacitor C dtp =Capacitance C drs , inductance L dr1 = Inductance L dt2 , capacitor C dr1 =Capacitance C dt2 , capacitor C drp =Capacitance C dts, Ms is L dp and L ds The blue and green lines represent the separate forward transmission circuit and reverse transmission circuit respectively, and the red line represents the shared circuit of the two transmission channels. sig1 and U sig2 They represent the signal sources for forward and reverse data transmission respectively. U1 and U2 represent the receiving voltages for forward and reverse data transmission respectively. When data is transmitted forward, the data carrier of the main side passes through the forward transmission circuit and the shared circuit (i.e., L dp , L dt1 , C dt1 , C dtp , L ds , L dr2 , C dr2 , C drs and R2) transmission. For reverse data transmission, the data carrier on the secondary side is transmitted through the reverse transmission circuit and the shared circuit (i.e., L ds , L dt2 , C dt2 , C dts , L dp , L dr1 , C dr1 , C drp and R1) transmission.

[0040] The structure and impedance characteristics of the primary side of the forward transmission of data transmission are as follows Figure 6 As shown, it can be seen that the impedance of the structure is zero at ω1 and infinite at ω2. The impedance of the structure can be expressed as:

[0041]

[0042] When data is transmitted in the forward direction, L dt1 , C dt1 and C dtp The formed parallel network acts as a wave blocking network, blocking the interference of the data source on the same side, and the wave blocking frequency is w2. Then L dt1 , C dt1 and C dtp Satisfaction relationship:

[0043]

[0044] The entire forward data transmission structure resonates at the angular frequency ω1. It can be seen that the impedance of the structure is zero at ω1, so:

[0045]

[0046] Combining equation (2) and equation (3), we can get C dtp Satisfies the following relationship:

[0047]

[0048] It can be seen that C dtp Satisfies a quadratic equation with two variables, has two roots, one of which is negative, discard it, then C dtp for:

[0049]

[0050] Combining equation (2) and equation (5), we can get C dt1 for:

[0051]

[0052] The structure and impedance characteristics of the primary side of the reverse transmission of data transmission are as follows Figure 7 As shown, it can be seen that the impedance of the structure is zero at ω2 and infinite at ω1. The impedance of the structure can be expressed as:

[0053]

[0054] When data is transmitted in the reverse direction, L dr1 , C dr1 and C drp The formed parallel network acts as a wave blocking network, blocking the interference of the data source on the same side, and the wave blocking frequency is ω1. Then L dr1 , C dr1 and C drp Satisfaction relationship:

[0055]

[0056] The entire reverse data transmission structure resonates at the angular frequency ω2. It can be seen that the impedance of the structure is zero at ω2, so:

[0057]

[0058] Combining equation (8) and equation (9), we can get C drp Satisfies the following relationship:

[0059]

[0060] It can be seen that C drp Two roots, one of which is negative, discard it, then C drp for:

[0061]

[0062] Combining equation (2) and equation (11), we can get C dr1 for:

[0063]

[0064] Based on the above parameter constraints, the system can pre-set the self-inductance value of the signal coil and the inductance value in each wave-blocking network according to the transmission power, and then determine the value of each compensation capacitor according to the carrier frequency of the signal transmission, thereby realizing full-duplex data communication.

[0065] In summary, the present application proposes a full-duplex wireless power and data transmission system based on a DDQ coil. By adopting a DDQ coil structure, the energy transmission channel and the data transmission channel circuit connection can be independent of each other. The cross-coupling between the energy coil and the data coil is theoretically 0, and there will be no cross-coupling in the magnetic field between the coils. At the same time, the impedance characteristics of the circuit will not be changed between the channels due to the introduction of accessory components. In addition, the data transmission channel adopts a two-resonance and one-rejection structure composed of an LCC parallel network. The signal transmission and signal reception on the same side can directly share the signal coil, reducing the coupler and independent series capacitors, simplifying the circuit structure, and through a new parameter configuration, it can meet the synchronous transmission of energy and data.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A full-duplex wireless power and data transmission system based on a DDQ coil, comprising an energy transmission channel and a data transmission channel, characterized in that: The coupling coil in the energy transmission channel is a pair of Q-type coils, and the coupling coil in the data transmission channel is a pair of DD coils, wherein: the two ends of the primary signal coil are connected in parallel with a primary data transmission branch formed by the primary signal source and the first transmitting wave blocking network in series, and a primary data receiving branch formed by the primary sampling resistor and the first receiving wave blocking network in series, and the two ends of the secondary signal coil are connected in parallel with a secondary data transmission branch formed by the secondary signal source and the second transmitting wave blocking network in series, and a secondary data receiving branch formed by the secondary sampling resistor and the second receiving wave blocking network in series, and the first transmitting wave blocking network, the first receiving wave blocking network, the second transmitting wave blocking network, and the second receiving wave blocking network all adopt a two-resonance one-rejection structure composed of an LCC parallel network, wherein: the carrier frequency of the primary signal source is used as the resonant frequency of the first transmitting wave blocking network and the second receiving wave blocking network, and the rejection frequency of the first receiving wave blocking network and the second transmitting wave blocking network; the carrier frequency of the secondary signal source is used as the resonant frequency of the second transmitting wave blocking network and the first receiving wave blocking network, and the rejection frequency of the second receiving wave blocking network and the first transmitting wave blocking network.

2. The full-duplex wireless power and data transmission system based on DDQ coil according to claim 1, characterized in that: The energy transmission channel includes a direct current power supply, a high-frequency inverter, a primary resonance network, an energy coupling coil, a secondary resonance network, a rectifier filter and an electrical load.

3. The full-duplex wireless power and data transmission system based on DDQ coil according to claim 2, characterized in that: The primary resonant network and the secondary resonant network both adopt LCC compensation networks.

4. The full-duplex wireless power and data transmission system based on DDQ coil according to claim 2 or 3, characterized in that: The operating frequency of the energy transmission channel is 85 kHz, the carrier frequency of the primary signal source is 4 MHz, and the carrier frequency of the secondary signal source is 6 MHz.

5. The full-duplex wireless power and data transmission system based on DDQ coil according to claim 1 or 2, characterized in that: The coupling coil in the energy transmission channel and the coupling coil in the data transmission channel are overlapped in the same direction, and the DD coil is covered by the Q-type coil.

6. The full-duplex wireless power and data transmission system based on DDQ coil according to claim 1 or 2, characterized in that: The first transmitting wave blocking network includes an inductor L dt1 and capacitor C dt1 The series branch formed and the capacitor C connected in parallel to the series branch dtp , and satisfies The first receiving wave blocking network includes an inductor L dr1 and capacitor C dr1 The series branch formed and the capacitor C connected in parallel to the series branch drp , and satisfies The second transmitting wave blocking network includes an inductor L dt2 and capacitor C dt2 The series branch formed and the capacitor C connected in parallel to the series branch dts , and satisfies The second receiving wave blocking network includes an inductor L dr2 and capacitor C dr2 The series branch formed and the capacitor C connected in parallel to the series branch drs , and satisfies w1 is the carrier angular frequency of the primary signal source, and w2 is the carrier angular frequency of the secondary signal source.

7. The full-duplex wireless power and data transmission system based on DDQ coil according to claim 6, characterized in that: Primary signal coil L dp = Secondary signal coil L ds , inductance L dt1 = Inductance L dr2 , capacitor C dt1 =Capacitance C dr2 , capacitor C dtp =Capacitance C drs , inductance L dr1 = Inductance L dt2 , capacitor C dr1 =Capacitance C dt2 , capacitor C drp =Capacitance C dts .

8. The full-duplex wireless power and data transmission system based on DDQ coil according to claim 7, characterized in that: The components in the data transmission channel meet the following requirements:

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