Axial flux PCB stator microgenerator for pipeline energy recovery

Abstract

The invention discloses an axial magnetic flux PCB stator microgenerator for pipeline energy recovery, and relates to the technical field of microgenerators. The axial magnetic flux PCB stator micro generator comprises paddles, a PCB stator, a rotor, a post-stage electric energy conversion circuit and an energy storage unit, the other end of the rotating shaft penetrates through the pipeline and the PCB stator and is connected with a rotor outside the pipeline; the PCB stator and the post-stage electric energy conversion circuit are electrically connected with the energy storage unit. Fluid in a pipeline impacts the blades, the blades drive the rotor to generate a rotating dynamic magnetic field in the rotating process, the copper wire on the PCB stator cuts the magnetic field to form induced electromotive force, alternating-current low-voltage electricity is generated, and then the alternating-current low-voltage electricity is boosted to common direct current to be stored in the energy storage unit. By additionally arranging the low-speed paddles, the micro generator can generate weak power generation under the electromagnetic induction effect by utilizing kinetic energy rotation of fluid of a pipeline, and electric energy is converted and stored in the energy storage unit through the efficient electric energy conversion circuit.

Description

Technical Field

[0001] The invention belongs to the technical field of micro generators, and in particular relates to an axial magnetic flux PCB stator micro generator for pipeline energy recovery. Background Art

[0002] With the gradual maturity and application of digital twin technology, wireless sensors have been widely used. These sensors send monitoring information of the real physical world to data terminals, thereby providing data support for digital twins. However, how to provide power for these wireless sensors for a long time is an urgent problem to be solved.

[0003] Existing methods mainly focus on using environmental energy harvesting to achieve self-powering of such wireless sensors to avoid long power lines. This solution based on environmental micro-energy for power supply, the environmental energy recovery device usually uses piezoelectric materials combined with charged liquids to achieve special power generation. It mainly designs a micro-energy power generation device based on environmental vibration by combining charged special solutions with piezoelectric materials. It can be applied to energy recovery and utilization such as human kinetic energy and wave energy. However, in the application scenarios of pipeline systems such as urban water supply, gas pipelines, and agricultural irrigation water pipe systems, there are the following problems:

[0004] 1) The power generation device is large in size and cannot be well installed and fixed in the pipeline system;

[0005] 2) The vibration of the pipeline system is limited and cannot be compatible with the original pipeline system environment and achieve energy recovery.

[0006] Therefore, such existing special power generation devices are usually large in size and cannot be compatible with urban water supply, gas pipelines, and agricultural irrigation water pipe systems with limited volume and space. Therefore, it is urgent to develop special micro-power generation devices to meet the application requirements of such pipeline systems.

[0007] The present invention proposes an axial magnetic flux PCB stator micro-generator based on permanent magnetic material. By adding low-speed blades adapted to the common pipe sizes, the pipeline's own fluid kinetic energy can be used to rotate the micro-generator of the present invention to generate weak power generation under the electromagnetic induction effect, and the electric energy is stored in a lithium battery unit through an electric energy conversion circuit and an energy storage unit. Summary of the invention

[0008] The purpose of the present invention is to provide an axial flux PCB stator micro-generator for pipeline energy recovery, so as to solve the problems of the special power generation device in the prior art mentioned in the above background technology being bulky and incompatible with pipeline systems with limited volume and space.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] An axial flux PCB stator micro-generator for pipeline energy recovery includes a stator, a rotor, and a subsequent electric energy conversion circuit and an energy storage unit. The stator adopts a PCB stator and also includes blades;

[0011] The paddle is arranged inside the pipe, and the PCB stator is fixed outside the end of the pipe; the paddle is connected to one end of the rotating shaft, and the other end of the rotating shaft passes through the pipe and the PCB stator and is connected to the rotor outside the pipe; the PCB stator and the subsequent power conversion circuit are electrically connected to the energy storage unit;

[0012] The fluid in the pipeline impacts the blades, and the blades drive the rotor to generate a rotating dynamic magnetic field during the rotation process. The copper wire on the PCB stator cuts the magnetic field to form an induced electromotive force, thereby generating AC low-voltage electricity. The subsequent power conversion circuit and energy storage unit boost the AC low-voltage electricity to commonly used DC electricity and store it in the energy storage unit.

[0013] Preferably, the rotor comprises a permanent magnet, a rotor yoke and a rotor back iron;

[0014] The rotor yoke is connected to the rotating shaft, the permanent magnet is located between the PCB stator and the rotor yoke, and the permanent magnet is arranged in a reserved gap of the rotor yoke; and the side of the rotor yoke away from the permanent magnet is connected to the rotor back iron.

[0015] Preferably, the permanent magnet is in the shape of one-eighth sector, and eight of them are provided; the eight radially evenly distributed permanent magnets are limited by eight radially evenly distributed reserved gaps on the rotor yoke.

[0016] Preferably, the pipe is an L-shaped pipe, a through hole is provided at a corner of the pipe, a bearing is installed in the through hole; the PCB stator is fixedly connected to the outside of the corner of the pipe;

[0017] The end of the rotating shaft away from the blade passes through the bearing and the through hole on the PCB stator in sequence and is connected to the rotor yoke.

[0018] Furthermore, the blade is connected to one end of the rotating shaft through a spline, and the other end of the rotating shaft passes through the bearing and the through hole on the PCB stator in sequence to be spline-connected to the rotor yoke.

[0019] Furthermore, the PCB stator is threadedly connected at three axial stator fixing positions outside the corner of the pipeline to achieve fixed connection to the outside of the corner of the pipeline.

[0020] Preferably, the blade is designed based on the NACA 4412 surface of aviation blades.

[0021] Preferably, driven by the blades at a rotation speed of 600 to 900 rpm, an induced electromotive force with a peak value of 0.2 to 0.3 V is generated.

[0022] Preferably, the post-stage power conversion circuit and energy storage unit include a diode-free AC input sampling circuit, a bridgeless AC-DC conversion circuit, a battery management circuit, and a control circuit;

[0023] Without using an input diode rectifier bridge and a diode sampling circuit, the micro generator is converted from a 0.2-0.3V AC output to a 4V output through closed-loop control, providing a stable DC input for the subsequent battery charging circuit.

[0024] Furthermore, the diode-free AC input sampling circuit is as follows:

[0025] The input side is connected to one end of the sampling resistor R1, the other end of the resistor R1 is connected to one end of the resistor R2 and one end of the resistor R3, and the other end of the resistor R2 is connected to the other end of the input side. The other end of the resistor R3 is connected to one end of the resistor R4 and the comparator C of the control part. MP1 The other end of resistor R4 is connected to the ground.

[0026] Furthermore, the bridgeless AC-DC conversion circuit is as follows:

[0027] The input side is connected to the drain of the switch tube S2 and one end of the inductor L1. The source of the switch tube S2 is connected to the cathode of the diode D2 and one end of the inductor L2. The other end of the inductor L2 is connected to the other end of the input side, the drain of the switch tube S1, and the output capacitor C o The positive electrode of the battery management chip is connected to pin 1, the source of the switch tube S1 is connected to the cathode of the diode D1 and the other end of the inductor L1, the anode of the diode D1 is connected to the anode of the diode D2, and the output capacitor C o The negative pole of the reference ground is connected.

[0028] Furthermore, the battery management circuit is specifically as follows:

[0029] The pin 1 of the battery management chip is connected to the output bus of the bridgeless AC-DC conversion circuit, and the pin 2 of the battery management chip is connected to the resistor R LED One end of the resistor R LED The other end of the LED display D L The anode of the battery management chip is connected, the pin 3 of the battery management chip is connected to one end of the load output mode selection key Bt1, the pin 4 of the battery management chip is connected to the positive electrode of the lithium battery, and the LED displays D L The negative electrode is connected to the other end of the load output mode selection key Bt1, the negative electrode of the lithium battery, and the circuit reference ground.

[0030] Furthermore, the control circuit is specifically as follows:

[0031] Comparator C MP1 The positive input receives the input voltage feedback vin,fb and with the comparator C MP1 The negative input signal output voltage feedback V o,fb Comparison, the generated logic signal v cmp They are sent to one input port of AND gate A2 and the input port of NOT gate respectively. MP2 The positive input receives the reference voltage V ref and with the comparator C MP2 The negative input signal input voltage v in,fb The error signal is sent to the comparator C after passing through the PI calculation module. MP3 The positive input of the comparator C MP3 The negative input port receives the sawtooth triangle wave signal, and the comparator C MP3 After comparing the positive and negative input signals, the output pulse signal G S0 . G S0 The output signals of AND gate A1 and AND gate A2 are respectively sent to one input port of AND gate A1 and the other input port of AND gate A2. The output signal of NOT gate is sent to the other input port of AND gate A1. The output signals of AND gate A1 and AND gate A2 are used to drive switch tube S1 and switch tube S2 respectively.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention utilizes the small size and light weight of the axial flux motor to realize the miniaturization of the power generation device; at the same time, the use of the PCB board as the motor stator can avoid the axial tension problem of the axial flux motor; and combined with the arc surface design of the blade, the fluid in the pipeline can be used to the maximum extent to realize the high-speed rotation of the micro-generator, thereby improving the power generation efficiency.

[0034] (2) Compared with other energy recovery power generation devices, the device of the present invention is based on the NACA4412 surface of aviation blades. By introducing information such as pipeline size, flow velocity, water level, etc., it is proposed that a low-speed multi-curved blade adapted to the pipeline can achieve energy recovery in a limited space environment. The blade surface design can adjust the inclination of the blade wing according to the flow velocity and flow rate of the fluid in different pipelines to achieve the optimal angle of attack of the oncoming fluid, thereby maximizing energy recovery.

[0035] (3) The present invention proposes a compact axial flux PCB stator micro motor, which uses only a thin printed circuit board (PCB) as the motor stator and combines the axial flux to generate a rotating magnetic field of the rotor, thereby realizing energy recovery in a limited space.

[0036] (4) Based on the input-free rectifier bridge conversion circuit, the present invention proposes a closed-loop control method for a diode-free AC input sampling circuit, thereby avoiding the forward conduction voltage and its corresponding AC input sampling error caused by the use of diodes in traditional AC input sampling, achieving efficient DC output of the micro-generator under low AC output, and storing electrical energy in the subsequent energy storage unit through the existing battery management chip FM5012. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the axial flux PCB stator micro-generator in the present invention;

[0038] Figure 2 It is a schematic diagram of the explosion of the internal components of the axial flux PCB stator micro-generator in the present invention;

[0039] Figure 3 It is a schematic diagram of the circuit system of the latter stage electric energy conversion circuit and the energy storage unit of the present invention;

[0040] Figure 4 This is a simulation result diagram of a 1.2m high water pipe of the axial flux PCB stator micro-generator under pipeline fluid impact in the present invention;

[0041] Figure 5 The magnetic flux density simulation result diagram of the axial magnetic flux PCB stator micro-generator of the present invention at a blade speed of 600 rpm ((a) is a bottom schematic diagram, (b) is a top schematic diagram);

[0042] Figure 6 The figure is a simulation result diagram of the open-circuit induced electromotive force of the axial flux PCB stator micro-generator of the present invention at the blade speeds of 600rpm, 750rpm, and 900rpm;

[0043] Figure 7 It is a key simulation waveform diagram of the bridgeless AC-DC conversion circuit, sampling circuit and control circuit of the present invention.

[0044] In the figure: 1. blade; 2. rotating shaft; 3. water pipe; 4. bearing; 5. PCB stator; 6. stator fixing position; 7. rotor; 8. permanent magnet; 9. rotor yoke; 10. rotor back iron; 11. post-stage power conversion circuit and energy storage unit; 12. diode-free AC input sampling circuit; 13. bridgeless AC-DC conversion circuit; 14. battery management circuit; 15. control circuit. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] Embodiment 1:

[0047] See also Figure 1-2 , an axial flux PCB stator micro-generator for pipeline energy recovery, the assembly diagram of its components is shown in Figure 2 As shown; the axial flux PCB stator micro generator includes a blade 1, a rotating shaft 2 connected to the axis of the blade 1, a bearing 4 installed on a water pipe 3, a PCB stator 5, a rotor 7 and a subsequent power conversion circuit and energy storage unit 11; the rotor 7 includes a permanent magnet 8, a rotor yoke 9, and a rotor back iron 10.

[0048] In this embodiment, the blade 1 is placed inside the customized water pipe 3, and the blade 1 is connected to one end of the rotating shaft 2 through a customized spline. The other end of the rotating shaft 2 passes through the through hole of the water pipe 3 and is connected to the bearing 4 fixed on the through hole of the water pipe 3; the bearing 4 is fixed to the through hole of the water pipe 3 by an interference connection. The PCB stator 5 is fixed to the side of the water pipe 3 with the through hole through three axial stator fixing positions 6, and the fixing method is a threaded connection realized by nuts or bolts; and the through hole of the PCB stator 5 maintains a concentric assembly relationship with the through hole of the water pipe 3. Eight radially evenly distributed permanent magnets 8 are limited by eight radially evenly distributed reserved gaps of the rotor yoke 9, and the rotor yoke 9 and the eight radially evenly distributed permanent magnets 8 are fixed together on one side of the circular surface of the rotor back iron 10, and the fixing method is bonding; the customized spline axis of the rotor yoke 9 maintains a concentric assembly relationship with the through hole of the rotor back iron 10; the customized spline of the rotor yoke 9 is connected to the customized spline at the other end of the rotating shaft 2.

[0049] Specifically, the PCB stator 5 only uses a thin printed circuit board (PCB), which is connected to the subsequent power conversion circuit and the energy storage unit 11; combined with the axial magnetic flux to generate a rotating magnetic field of the rotor, energy recovery can be achieved in a limited space.

[0050] Specifically, blade 1 is designed based on the NACA4412 surface of aviation blades. By introducing information such as pipeline size, flow rate, water level height, etc., it is proposed that a low-speed multi-curved blade adapted to the pipeline can achieve energy recovery in a limited space environment.

[0051] In this embodiment, the subsequent power conversion circuit and the energy storage unit 11 are as follows Figure 3 As shown, it includes a diode-free AC input sampling circuit 12, a bridgeless AC-DC conversion circuit 13, a battery management circuit 14, and a control circuit 15.

[0052] The diode-free AC input sampling circuit 12 includes a resistor R1, a resistor R2, a resistor R3 and a resistor R4;

[0053] The bridgeless AC-DC conversion circuit 13 includes a switch tube S1, a switch tube S2, an inductor L1, an inductor L2, a diode D1 and a diode D2;

[0054] The battery management circuit 14 includes a battery management chip, a resistor R LED And LED display D L ;

[0055] The control circuit 15 includes a comparator C MP1 , Comparator C MP2 and comparator C MP3 .

[0056] Specifically, the input side is connected to one end of the resistor R1, the drain of the switch tube S2, and one end of the inductor L1; the other end of the resistor R1 is connected to one end of the resistor R2 and one end of the resistor R3; the other end of the resistor R3 is connected to one end of the resistor R4 and the comparator C MP1 The other end of resistor R4 is connected to the ground.

[0057] The source of the switch tube S2 is connected to the cathode of the diode D2 and one end of the inductor L2. The other end of the inductor L1 is connected to the source of the switch tube S1 and the cathode of the diode D1. The anode of the diode D1 is connected to the anode of the diode D2 and the output capacitor C o The negative pole of the reference ground is connected.

[0058] The other end of the input side is connected to the other end of the resistor R2, the drain of the switch tube S1, the other end of the inductor L2, and the output capacitor C o The positive pole of the battery management chip is connected to pin 1.

[0059] The pin 1 of the battery management chip is connected to the output bus of the bridgeless AC-DC conversion circuit, and the pin 2 of the battery management chip is connected to the resistor R LED One end of the resistor R LED The other end of the LED display D L The anode of the battery management chip is connected; the pin 3 of the battery management chip is connected to one end of the load output mode selection key Bt1, the pin 4 of the battery management chip is connected to the positive electrode of the lithium battery, and the LED displays D L The negative electrode is connected to the other end of the load output mode selection key Bt1, the negative electrode of the lithium battery, and the circuit reference ground.

[0060] Specifically, the principle of the control circuit 15 is as follows:

[0061] Comparator C MP1The positive input receives the input voltage feedback v in,fb and with the comparator C MP1 The negative input signal output voltage feedback V o,fb Comparison, the generated logic signal v cmp They are sent to one input port of AND gate A2 and the input port of NOT gate respectively.

[0062] Comparator C MP2 The positive input receives the reference voltage V ref and with the comparator C MP2 The negative input signal input voltage v in,fb The error signal is sent to the comparator C after passing through the PI calculation module. MP3 The positive input of the comparator C MP3 The negative input port receives the sawtooth triangle wave signal, and the comparator C MP3 After comparing the positive and negative input signals, the output pulse signal G S0 .

[0063] G S0 The output signals of AND gate A1 and AND gate A2 are respectively sent to one input port of AND gate A1 and the other input port of AND gate A2. The output signal of NOT gate is sent to the other input port of AND gate A1. The output signals of AND gate A1 and AND gate A2 are used to drive switch tube S1 and switch tube S2 respectively.

[0064] When the bridgeless AC-DC converter circuit works in the positive half cycle, the AC input is in the positive half cycle. Figure 3 The input voltage sampling feedback v in,fb Always greater than the output voltage sampling feedback V o,fb Therefore, in the control circuit, only the driving signal G2 has a pulse signal, and the driving signal G1 is always equal to 0, and the bridgeless AC-DC conversion circuit has working mode 1, working mode 2, and working mode 3.

[0065] Working mode 1: In this stage, the switch tube S2 is in the on state, the input end charges the inductor L2, and the inductor current i L2 Linear increase. Output capacitor C o Provide energy for the load.

[0066] Working mode 2: When the switch tube S2 is turned off, working mode 2 begins. The diode D2 is turned on and the inductor current i L2 Provides a freewheeling path, and the energy stored in the inductor L2 supplies energy to the load end. The inductor current i L2 Linear decrease.

[0067] Working mode 3: When the inductor current i L2When the linear voltage drops to zero, the working mode 3 starts. The switch tube S2 and the diode D2 are both in the off state. The output capacitor C o Provide energy for the load.

[0068] When the bridgeless AC-DC converter circuit works in the negative half cycle, the AC input is in the negative half cycle. Figure 3 The input voltage sampling feedback v in,fb Always less than the output voltage sampling feedback V o,fb Therefore, in the control circuit, only the driving signal G1 has a pulse signal, and the driving signal G2 is always equal to 0, and the bridgeless AC-DC conversion circuit has working modes 4, 5, and 6.

[0069] Working mode 4: In this stage, the switch tube S1 is in the on state, the input end charges the inductor L1, and the inductor current i L1 Linear increase. Output capacitor C o Provide energy for the load.

[0070] Working mode 5: When the switch tube S1 is turned off, working mode 5 begins. The diode D1 is turned on and the inductor current i L1 Provides a freewheeling path, the input end and the energy stored in the inductor L1 jointly supply energy to the load end, the inductor current i L1 Linear decrease.

[0071] Working mode 6: When the inductor current i L1 When the linear voltage drops to zero, the working mode 6 starts. The switch tube S1 and the output diode D1 are both in the off state. The output capacitor Co supplies energy to the load.

[0072] Compared with the prior art, the bridgeless AC-DC converter circuit in the present invention does not use the traditional isolated sampling circuit and the sampling circuit with a diode. Because the 0.3V input voltage cannot be sampled by the traditional sampling circuit and the existing isolated sampling circuit, otherwise it will cause the switch tube S1 and the switch tube S2 to partially work in a non-realizable mode. The circuit topology of the present invention directly raises the input relative to the reference ground to the output voltage V o , the traditional AC input sampling can be realized by directly using a resistive DC sampling circuit, thereby realizing diode-free sampling and avoiding the problem of the switch tube being unable to drive due to sampling errors.

[0073] like Figure 4As shown, the working principle of the micro generator in the present invention is described as follows: the fluid in the pipeline system impacts the blade 1 and causes the blade 1 to rotate rapidly; the rotating blade 1 then drives the rotor 7 of the micro motor to rotate through the rotating shaft 2; there are permanent magnets 8 and rotor back iron 10 on the rotor 7, which generate a rotating dynamic magnetic field during its rotation; the copper wire on the PCB stator 5 cuts the magnetic field to form an induced electromotive force; the generated induced electromotive force is AC low voltage electricity, which is converted into DC electricity through the subsequent power conversion circuit and supplies power to the energy storage unit.

[0074] Experimental verification:

[0075] In order to verify the structural feasibility of the present invention and the correctness of the energy recovery principle, a finite element analysis model of the axial flux PCB stator motor was constructed using the simulation software Jmag.

[0076] The specific parameters are: the diameter of the rotor back iron 10 is 7.2 cm, the diameter of the internal center through hole is 1.4 cm, the thickness is 0.4 cm, and the material is China steel 50CS470; the thickness of the rotor yoke 9 is 5 cm and the diameter is 7.2 cm; the radial side length of the one-eighth sector-shaped neodymium iron boron (NdFeB) permanent magnet 8 is 0.3 cm; the thickness of the PCB stator 5 is 0.1 cm, and the axial distance between the PCB stator 5 and the permanent magnet 8 is 0.1 cm.

[0077] Figure 5 It is the simulation result of magnetic flux density of the axial flux PCB stator motor of the present invention when the blade is 600rpm. Figure 6 This is the open circuit induced electromotive force simulation result of the present invention. Figure 5 and Figure 6 It can be seen that the present invention can achieve an induced electromotive force output of 0.2 to 0.3 V peak value under the blade speed of 600 to 900 rpm (simulating the blade speed driven by the flow velocity of water at a height of 1.2 m). The output induced electromotive force can be converted into direct current by the subsequent power conversion circuit and achieve a 5 V voltage output to power the subsequent energy storage unit.

[0078] On the other hand, the simulation software Psim is used to model the bridgeless AC-DC conversion circuit and control circuit without diode sampling to verify the effectiveness of power conversion with 4V output under 0.3Vac AC input.

[0079] Specific parameters: AC input adopts sinusoidal signal fitting, AC voltage peak is 0.3V, frequency is 20Hz, inductance L1, L2 is 4.7uH, output capacitance C oThe resistor is 100uF, the output voltage is 4.0V, the load is 300Ω, the power is 5mW, the switching frequency is 47k, the P in the PI parameters is 0.3, I is 0.005, and the resistance of the AC input sampling circuit without a diode is R1=R2=1MΩ, R1=R2=570kΩ.

[0080] Figure 7 The main waveform simulation results of the bridgeless AC-DC conversion circuit, control circuit, and diode-free AC sampling circuit of the present invention are shown in FIG. Figure 7 It can be seen that the diode-free AC sampling circuit can provide a suitable input voltage sampling for the control circuit and compare it with the output voltage to generate a control signal v cmp To distinguish the positive and negative half-cycle working modes of the circuit; secondly, the bridgeless AC-DC conversion circuit can achieve a 4V DC output under a 0.3V peak AC input without an input rectifier diode, and the circuit works stably, the working mode is consistent with the theoretical analysis, and it has the conditions to supply energy to the subsequent battery management system. From the above simulation results, it can be seen that the present invention can be combined with the existing pipeline system to achieve energy recovery in a small enclosed space and supply energy to the subsequent energy storage unit, thereby realizing self-powering of the pipeline status monitoring device. Through the above examples, it can be explained that the present invention can achieve self-powering of monitoring devices in multiple pipeline application scenarios such as urban pipeline water supply systems, agricultural pipeline irrigation systems, and industrial pipeline systems.

[0081] The above description is only used to help understand the method of the present invention and its core essence, but the protection scope of the present invention is not limited thereto. For those skilled in the art in the art, equivalent replacement or change according to the technical solution and inventive concept of the present invention within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An axial flux PCB stator micro generator for pipeline energy recovery, comprising a stator, a rotor (7) and a subsequent power conversion circuit and an energy storage unit (11), characterized in that: The stator adopts a PCB stator (5), and also includes a blade (1); The blade (1) is arranged inside the pipe, and the PCB stator (5) is fixed to the outside of the end of the pipe; the blade (1) is connected to one end of the rotating shaft (2), and the other end of the rotating shaft (2) passes through the pipe and the PCB stator (5) to be connected to the rotor (7) outside the pipe; the PCB stator (5) and the subsequent electric energy conversion circuit are electrically connected to the energy storage unit (11); The fluid in the pipeline impacts the blades (1), and the blades (1) drive the rotor (7) to generate a rotating dynamic magnetic field during the rotation process. The copper wire on the PCB stator (5) cuts the magnetic field to form an induced electromotive force, thereby generating AC low-voltage electricity. The subsequent power conversion circuit and energy storage unit (11) boost the AC low-voltage electricity to common DC electricity and store it in the energy storage unit.

2. The axial flux PCB stator micro-generator for pipeline energy recovery according to claim 1 is characterized in that: The rotor (7) comprises a permanent magnet (8), a rotor yoke (9) and a rotor back iron (10); The rotor yoke (9) is connected to the rotating shaft (2), the permanent magnet (8) is located between the PCB stator (5) and the rotor yoke (9), and the permanent magnet (8) is arranged in a reserved gap of the rotor yoke (9); and the side of the rotor yoke (9) away from the permanent magnet (8) is connected to the rotor back iron (10).

3. The axial flux PCB stator micro-generator for pipeline energy recovery according to claim 2, characterized in that: The permanent magnet (8) is in the shape of a one-eighth sector, and eight of them are provided; the eight radially evenly distributed permanent magnets (8) are limited by eight radially evenly distributed reserved gaps on the rotor yoke (9).

4. The axial flux PCB stator micro-generator for pipeline energy recovery according to claim 3 is characterized in that: The pipeline is an L-shaped pipeline, a through hole is provided at a corner of the pipeline, and a bearing (4) is installed in the through hole; the PCB stator (5) is fixedly connected to the outside of the corner of the pipeline; The end of the rotating shaft (2) away from the blade (1) passes through the bearing (4) and the through hole on the PCB stator (5) in sequence and is connected to the rotor yoke (9).

5. The axial flux PCB stator micro-generator for pipeline energy recovery according to claim 1, characterized in that: The blade (1) is designed based on the NACA 4412 curved surface of aviation blades.

6. The axial flux PCB stator micro-generator for pipeline energy recovery according to claim 5, characterized in that: Driven by a blade (1) with a rotation speed of 600 to 900 rpm, an induced electromotive force with a peak value of 0.2 to 0.3 V is generated.

7. The axial flux PCB stator micro-generator for pipeline energy recovery according to claim 6, characterized in that: The latter electric energy conversion circuit and energy storage unit (11) comprises a diode-free AC input sampling circuit (12), a bridgeless AC-DC conversion circuit (13), a battery management circuit (14), and a control circuit (15); Without using an input diode rectifier bridge and a diode sampling circuit, the micro generator is converted from a 0.2-0.3V AC output to a 4V output through closed-loop control.

Images