Multi-relay coil wireless power supply system with bidirectional DC-DC converter for energy storage

Abstract

The invention is suitable for the technical field of wireless charging, and provides a multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage, which comprises a transmitting side structure unit, a relay coil structure unit, a receiving side structure unit and a three-port structure unit, the transmitting side structure unit is connected with the repeating coil structure unit, the repeating coil structure unit is connected with the receiving side structure unit, and the receiving side structure unit is connected with the three-port structure unit; the three-port structure unit comprises a three-port DC-to-DC converter, a DC support capacitor, a load and an energy storage battery; a first port of the three-port DC-to-DC converter is connected with the receiving side structure unit, a second port is connected with the energy storage battery, a third port is respectively connected with a first end of the DC support capacitor and a first end of the load, and a second end of the DC support capacitor and a second end of the load are in common ground; efficient conversion and transmission of electric energy are achieved, and the energy utilization rate of the energy storage system is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of wireless charging technology, and in particular to a multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage. Background Art

[0002] Compared to traditional wired power transmission technologies, wireless power transmission systems offer the advantage of contactless power delivery, reducing the wear and limitations associated with wired connections and significantly reducing sparks caused by friction between devices due to physical contact. This makes them suitable for medical devices, consumer electronics, and industrial equipment that requires frequent movement. Multi-relay coil technology significantly improves transmission distance and efficiency by adding relay coils between the transmitter and receiver. These relay coils serve as intermediate nodes for energy transmission. The relay system's transmitting, relay, and receiving coils typically utilize a series or parallel arrangement of inductors and capacitors. Contactless power transmission systems are structurally loosely coupled, and the characteristics of the coil system significantly impact the stability and efficiency of the entire system.

[0003] Current traditional wireless power systems can usually only achieve unidirectional energy transmission, with energy only flowing from the transmitting coil to the receiving coil and unable to achieve reverse energy flow; and they are unable to feed back the excess energy generated or stored energy by the terminal device to the power supply or energy storage battery, thereby limiting the system's functional expansion and energy utilization efficiency. Summary of the Invention

[0004] The present invention provides a multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage, which is used to solve the problems of system function expansion and low energy utilization efficiency.

[0005] The present invention provides a multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage, comprising: A transmitting side structure unit, a relay coil structure unit, a receiving side structure unit and a three-port structure unit; the transmitting side structure unit is connected to the relay coil structure unit, the relay coil structure unit is connected to the receiving side structure unit, and the receiving side structure unit is connected to the three-port structure unit; The three-port structural unit includes a three-port DC-to-DC converter, a DC support capacitor, a load and an energy storage battery; the first port of the three-port DC-to-DC converter is connected to the receiving side structural unit, the second port of the three-port DC-to-DC converter is connected to the energy storage battery, and the third port of the three-port DC-to-DC converter is respectively connected to the first end of the DC support capacitor and the first end of the load, the second ends of the DC support capacitor and the second ends of the load are commonly grounded.

[0006] Furthermore, the transmitting-side structural unit includes a DC power supply, a transmitting coil, a full-bridge inverter, and a first resonant compensation capacitor; the output end of the DC power supply is connected to the input end of the full-bridge inverter; the output end of the full-bridge inverter is connected to the first end of the first resonant compensation capacitor; and the second end of the first resonant compensation capacitor is connected to the input end of the transmitting coil.

[0007] Furthermore, the receiving side structural unit includes a receiving coil, a second resonant compensation capacitor and a passive rectifier; the first end of the second resonant compensation capacitor is connected to the output end of the receiving coil; the second end of the second resonant compensation capacitor is connected to the input end of the passive rectifier.

[0008] Furthermore, the relay coil structure unit includes at least two relay coils arranged in sequence, and each relay coil is connected in series with a resonant compensation capacitor to form a corresponding resonant circuit.

[0009] Furthermore, the three-port DC-DC converter integrates a Buck module and a half-bridge bidirectional Buck-Boost module, and is configured to switch the charging or discharging mode of the energy storage battery according to load demand.

[0010] Furthermore, the Buck module includes a first switching tube, a diode, a first inductor and a first capacitor; the drain of the first switching tube is connected to the first port of the three-port DC-DC converter; the source of the first switching tube is connected to the first end of the diode and the first end of the first inductor; the second end of the diode and the second end of the first inductor are connected to the third port of the three-port DC-DC converter through the first capacitor.

[0011] Furthermore, the half-bridge bidirectional Buck-Boost module includes a second switch tube, a third switch tube, a second inductor and a second capacitor; the second switch tube and the third switch tube are complementary to each other, the second switch tube is connected to the third port of the three-port DC-DC converter and the first end of the second inductor; the second end of the second inductor is connected to the second capacitor and the second port of the three-port DC-DC converter.

[0012] Furthermore, the three-port DC-DC converter has two operating modes; wherein, in mode 1, energy flows from the first port of the three-port DC-DC converter to the third port of the three-port DC-DC converter to power the load, and at the same time flows to the second port of the three-port DC-DC converter to charge the energy storage battery; in mode 2, energy flows from the first port of the three-port DC-DC converter and the second port of the three-port DC-DC converter to the third port of the three-port DC-DC converter to power the load, and at this time the energy storage battery is discharged; the three-port DC-DC converter is used to automatically switch between mode 1 and mode 2 according to load demand.

[0013] Furthermore, the full-bridge inverter adopts four MOSFET bridge arms, and the gate trigger signal is a complementary PWM waveform.

[0014] Furthermore, the passive rectifier is a full-bridge rectifier circuit composed of four diodes, and the output end of the passive rectifier is connected to the first port of the three-port DC-DC converter.

[0015] It can be seen from the above technical solutions that the present invention has the following advantages: The present invention embeds a multi-relay coil structure with wireless power supply functionality within an insulator, solving the wireless power supply problem for transmission line monitoring equipment with different requirements. A three-port structural unit is also provided. The wireless power receiving-side structural unit is connected to the first port of the three-port DC-DC converter, the second port is connected to an energy storage battery, and the third port outputs electrical energy to power the load. The transmitted energy is regulated by controlling the charge and discharge of the energy storage battery to maintain load voltage stability. The system of the present invention can not only power terminal devices but also feed excess energy from the devices back to the energy storage battery, significantly improving the overall stability and sustainability of the online monitoring equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a topological diagram of the system circuit in the present invention; Figure 2 Schematic diagram of the energy control implementation process in the present invention. DETAILED DESCRIPTION

[0017] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "corresponding to" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0018] Example 1 See also Figure 1 In the present invention, a multi-relay coil wireless power supply system with bidirectional DC-to-DC converter energy storage includes four parts: a transmitting side structure unit, a relay coil structure unit, a receiving side structure unit and a three-port structure unit, wherein the transmitting side structure unit is connected to the relay coil structure unit, the relay coil structure unit is connected to the receiving side structure unit, and the receiving side structure unit is connected to the three-port structure unit; the three-port structure unit includes a three-port DC-to-DC converter, a DC support capacitor, a load and an energy storage battery; the first port of the three-port DC-to-DC converter is connected to the receiving side structure unit, the second port of the three-port DC-to-DC converter is connected to the energy storage battery, and the third port of the three-port DC-to-DC converter is respectively connected to the first end of the DC support capacitor and the first end of the load, the second end of the DC support capacitor and the second end of the load are commonly grounded.

[0019] Specifically, the three-port structural unit here is a three-port network, and the three-port DC-DC converter is composed of two DC-DC converters, integrating a Buck module and a half-bridge bidirectional Buck-Boost module, wherein the main circuit is a Buck converter and the auxiliary circuit is a half-bridge bidirectional Buck-Boost converter; the three-port DC-DC converter is configured to switch the charging or discharging mode of the energy storage battery according to load demand.

[0020] The Buck module includes a first switch tube, a diode and a first inductor, namely Figure 1 The first switch tube ,diode and the first inductor The duty cycle generates a PWM modulation signal to control the first switch tube On and off; the first switch tube The drain of the first switch is connected to the first port (port 1) of the three-port DC-DC converter; The source-connected diode The first end and the first inductor The first end of the diode The second end and the first inductor The second end of the first capacitor Connect to the third port (Port 3) of the three-port DC-DC converter.

[0021] The half-bridge bidirectional Buck-Boost module includes a second switch tube, a third switch tube, a second inductor and a second capacitor; the second switch tube and the third switch tube are complementary to each other, and the second switch tube is connected to the third port of the three-port DC-DC converter and the first end of the second inductor; the second end of the second inductor is connected to the second capacitor and the second port of the three-port DC-DC converter; that is, Figure 1 A pair of second switching tubes located in the upper bridge arm and the lower bridge arm , the third switch tube , the bridge arm switch tubes are complementary turned on, the duty cycle is adjustable, and the midpoint of the bridge arm passes through the second inductor and the second capacitor Connect to the energy storage battery; charge and discharge the energy storage battery by adjusting the external phase shift angle of port 1 and port 2.

[0022] Furthermore, the transmitting side structural unit includes a DC power supply, a transmitting coil, a full-bridge inverter and a first resonant compensation capacitor; the output end of the DC power supply is connected to the input end of the full-bridge inverter; the output end of the full-bridge inverter is connected to the first end of the first resonant compensation capacitor; the second end of the first resonant compensation capacitor is connected to the input end of the transmitting coil; that is, Figure 1 The DC power input voltage is , connected to the full-bridge inverter circuit to convert it into high-frequency AC The full-bridge inverter uses four MOSFET bridge arms, and the gate trigger signal is a complementary PWM waveform; that is, 、 、 and Four MOSFETs, with their corresponding gate trigger signals The output end of the inverter and the transmitting coil connected, with the middle series compensation resonant capacitor .

[0023] Furthermore, the relay coil structure unit includes at least two relay coils arranged in sequence, each relay coil is connected in series with a resonant compensation capacitor to form a corresponding resonant circuit; wherein the resonant circuit of the first relay coil is magnetically coupled to the output end of the transmitting coil, and the resonant circuit of the last relay coil is magnetically coupled to the input end of the receiving coil, and the resonant circuits of any two adjacent relay coils are magnetically coupled to each other.

[0024] Furthermore, the receiving side structural unit includes a receiving coil, a second resonant compensation capacitor and a passive rectifier; the first end of the second resonant compensation capacitor is connected to the output end of the receiving coil; the second end of the second resonant compensation capacitor is connected to the input end of the passive rectifier.

[0025] Specific examples Figure 1 The relay coil structure unit includes a relay coil , relay coil , ..., until the end relay coil , and their mutual magnetic coupling inductance are 、 、……、 , each circuit is connected to its own resonant compensation capacitor 、 , ..., until the end relay coil resonant compensation capacitor ;Receiving coil With the front end relay coil Magnetic coupling, its mutual inductance is The series resonant compensation capacitor of the receiving coil is , the receiving side compensation network is connected to the passive rectifier; the passive rectifier is composed of a diode composition.

[0026] Furthermore, the three-port DC-DC converter has two operating modes; in mode 1, energy flows from the first port of the three-port DC-DC converter to the third port of the three-port DC-DC converter to power the load, and at the same time flows to the second port of the three-port DC-DC converter to charge the energy storage battery; in mode 2, energy flows from the first port of the three-port DC-DC converter and the second port of the three-port DC-DC converter to the third port of the three-port DC-DC converter to power the load, and the energy storage battery is discharged at this time; the three-port DC-DC converter is used to automatically switch between mode 1 and mode 2 according to load demand.

[0027] Specifically, mode 1: the multi-relay wireless power receiving side transmits power to the load through a three-port network While supplying power, the energy storage battery is charged. At this time, the output current of port 3 is Mode 2: When the multi-relay wireless power supply cannot provide the power required for the load to stabilize the voltage, the wireless power receiving side and the energy storage battery pack discharge through the three-port network to simultaneously supply power to the load. Power supply, at this time ,Depending on the load conditions (light load or heavy load), the converter can operate in mode 1 or mode 2, and can realize automatic switching of the working mode while stabilizing the output load voltage.

[0028] See also Figure 2The block diagram of the system control method is as follows. The implementation process of the system adaptive voltage charge and discharge control is described in detail: 1. At the initial stage of system power-on, initialize the output voltage of the adaptive voltage controller in the system to 0; set the voltage and current sampling sensor measurement data; among which, the first voltage sampling sensor measures the load voltage ， The second voltage sampling sensor measures the battery voltage , the rectifier output current measured by the third current sampling sensor ;initialization It is in disconnected state to ensure the power path is safe when the system is powered on; 2. The power transmission between the multi-relay coil wireless power supply main circuit and the load is achieved by controlling the duty cycle of the buck converter. In its duty cycle voltage regulation control loop, the actual load voltage measured by the first voltage sampling sensor is used as the load voltage. The reference output voltage is set with Compare and get the deviation signal ; The deviation signal After PI control and limiting links, the first duty cycle adjustment amount is output , After PWM modulation, the first switch tube is driven Work; 3. The power transmission channel of the energy storage battery charging and discharging circuit is controlled by the second switch tube of the half-bridge bidirectional DC-DC converter. , the third switch tube The second duty cycle adjustment amount The converter works in step-down state to charge the battery, and vice versa, the converter works in step-up state to power the load. The third current sampling sensor measures the rectifier output current , used to judge the working status of the system. , the system provides stable power supply for the load and charges the energy storage battery, and the half-bridge bidirectional DC-DC converter is in buck mode (battery charging); when , the energy storage battery discharges to provide the load with a stable output voltage, and the half-bridge bidirectional DC-DC converter is in boost mode (load power supply); As the rectifier output isolation switch, its status is determined by Control: If , then closed , allowing rectifier power to flow to the buck converter and half-bridge input; if , then disconnect , isolate the rectifier output to ensure independent battery discharge path; 4. When the system is in charging state ( and the battery needs to be charged), the battery voltage measured by the second voltage sampling sensor is With a given rated charging voltage Compare and get the deviation signal; input the deviation into the PI controller and the limit link, and output the second duty cycle adjustment value , As the second switch tube of the half-bridge bidirectional DC-DC bridge arm Control signal (third switch tube complementary conduction); 5. Use amplitude The triangular wave is used as the carrier, and the duty cycle is Pulse sequence, which is used to drive the second switch tube of the half-bridge bidirectional DC-DC converter , the third switch tube of the bridge arm With the second switch Complementary conduction, duty cycle is (1- ).

[0029] The above-mentioned bidirectional DC-DC energy storage system with wireless power supply function can effectively ensure the stability of the load voltage. At the same time, through circuit design and control process, the three-port structural unit can realize efficient conversion and transmission of electric energy, effectively improving the energy utilization rate of the energy storage system.

[0030] It is understandable that those skilled in the art can, under the guidance of the above embodiments, combine various implementation methods in the above embodiments to obtain technical solutions of multiple implementation methods.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage, characterized in that: include: Transmitting side structural unit, relay coil structural unit, receiving side structural unit and three-port structural unit; The transmitting side structure unit is connected to the relay coil structure unit, the relay coil structure unit is connected to the receiving side structure unit, and the receiving side structure unit is connected to the three-port structure unit; The three-port structural unit includes a three-port DC-to-DC converter, a DC support capacitor, a load and an energy storage battery; the first port of the three-port DC-to-DC converter is connected to the receiving side structural unit, the second port of the three-port DC-to-DC converter is connected to the energy storage battery, and the third port of the three-port DC-to-DC converter is respectively connected to the first end of the DC support capacitor and the first end of the load, the second ends of the DC support capacitor and the second ends of the load are commonly grounded.

2. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 1 is characterized in that: The transmitting-side structural unit includes a DC power supply, a transmitting coil, a full-bridge inverter, and a first resonant compensation capacitor; the output end of the DC power supply is connected to the input end of the full-bridge inverter; the output end of the full-bridge inverter is connected to the first end of the first resonant compensation capacitor; and the second end of the first resonant compensation capacitor is connected to the input end of the transmitting coil.

3. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 1, characterized in that: The receiving side structural unit includes a receiving coil, a second resonant compensation capacitor and a passive rectifier; the first end of the second resonant compensation capacitor is connected to the output end of the receiving coil; the second end of the second resonant compensation capacitor is connected to the input end of the passive rectifier.

4. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 1, characterized in that: The relay coil structure unit includes at least two relay coils arranged in sequence, and each relay coil is connected in series with a resonant compensation capacitor to form a corresponding resonant circuit.

5. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 1, characterized in that: The three-port DC-DC converter integrates a Buck module and a half-bridge bidirectional Buck-Boost module, and is configured to switch the charging or discharging mode of the energy storage battery according to load demand.

6. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 5, characterized in that: The Buck module includes a first switching tube, a diode, a first inductor and a first capacitor; the drain of the first switching tube is connected to the first port of the three-port DC-DC converter; the source of the first switching tube is connected to the first end of the diode and the first end of the first inductor; the second end of the diode and the second end of the first inductor are connected to the third port of the three-port DC-DC converter through the first capacitor.

7. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 6, characterized in that: The half-bridge bidirectional Buck-Boost module includes a second switch tube, a third switch tube, a second inductor and a second capacitor; the second switch tube and the third switch tube are complementary to each other, the second switch tube is connected to the third port of the three-port DC-DC converter and the first end of the second inductor; the second end of the second inductor is connected to the second capacitor and the second port of the three-port DC-DC converter.

8. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 5, characterized in that: The three-port DC-DC converter has two operating modes; in mode 1, energy flows from the first port of the three-port DC-DC converter to the third port of the three-port DC-DC converter to power the load, and at the same time flows to the second port of the three-port DC-DC converter to charge the energy storage battery; in mode 2, energy flows from the first port of the three-port DC-DC converter and the second port of the three-port DC-DC converter to the third port of the three-port DC-DC converter to power the load, and the energy storage battery is discharged at this time; the three-port DC-DC converter is used to automatically switch between mode 1 and mode 2 according to load demand.

9. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 2, characterized in that: The full-bridge inverter adopts four MOSFET bridge arms, and the gate trigger signal is a complementary PWM waveform.

10. The multi-relay coil wireless power supply system with bidirectional DC-DC converter energy storage according to claim 3, characterized in that: The passive rectifier is a full-bridge rectifier circuit composed of four diodes, and the output end of the passive rectifier is connected to the first port of the three-port DC-DC converter.

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