Power supply method for power line inspection robot based on electromagnetic induction

Abstract

The application discloses a power supply method for a power transmission line inspection robot based on electromagnetic induction, and belongs to the technical field of power supply for power transmission line inspection robots, which comprises the following steps: a magnetic circuit power taking assembly capable of being opened and closed is arranged on the inspection robot, the magnetic circuit power taking assembly comprises two half-ring magnetic cores and a power taking coil wound on the magnetic cores, the two half-ring magnetic cores form a closed magnetic loop around a power transmission conductor when closed, and an alternating electromotive force is inducted on the power taking coil based on the principle of electromagnetic induction; the current of the power transmission conductor and the voltage of a direct current bus are collected in real time, and it is judged whether the inspection robot is currently in a normal running working condition or an obstacle crossing magnetic circuit opening and closing working condition according to the current and the voltage. Through the cooperative control of multi-winding switching and virtual impedance matching, the application completely solves the problems that the traditional CT power taking is difficult to start under small current and is easy to saturate under large current, and realizes efficient and stable power taking in the range of 3A to 1000A conductor current.

Description

Technical Field

[0001] This invention belongs to the field of power supply technology for power transmission line inspection robots, specifically relating to a method and system for uninterrupted power supply to power transmission line inspection robots based on electromagnetic induction. It aims to solve the problems of stable power supply for inspection robots under a wide range of conductor currents and power interruption caused by the disconnection of the power supply module during obstacle crossing. Background Technology

[0002] With the development of power operation and maintenance technology, line inspection robots are widely used for health monitoring of high-voltage transmission lines. Currently, most line inspection robots rely on onboard batteries or solar panels for power, which has inherent drawbacks such as short range and susceptibility to weather conditions. In recent years, non-contact power extraction technology based on the principle of electromagnetic induction (CT power extraction) has gradually become the core power supply solution for long-range line inspection robots due to its advantages such as safety, stability, and high power extraction. However, existing CT power extraction technology still faces technical bottlenecks in practical engineering applications: poor energy extraction stability over a wide current range, severe fluctuations in transmission line load, and conductor currents that often vary from a few amperes (no-load or light load) to thousands of amperes (heavy load or fault). Traditional single-winding CT power extraction devices struggle to establish sufficient induced electromotive force under low current, preventing the robot from starting; under high current, deep core saturation is easily caused, leading to uncontrolled output voltage, burnout of downstream circuits, and even safety accidents. Therefore, there is an urgent need for a new energy supply method for line inspection robots that can adapt to the full range of conductor currents and provide uninterrupted power supply during obstacle crossing. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an energy supply method for a power transmission line inspection robot based on electromagnetic induction, which solves the technical problem of maintaining the stability of the DC bus voltage of the inspection robot in an extremely wide conductor current range of 3A to 1000A.

[0004] The objective of this invention is achieved as follows: a power supply method for a power transmission line inspection robot based on electromagnetic induction, comprising the following steps: equipping the inspection robot with an openable magnetic circuit power-harvesting component, the component comprising two semi-ring magnetic cores and a power-harvesting coil wound around the cores; when the two semi-ring magnetic cores are closed, they form a closed magnetic circuit around the transmission conductor; based on the principle of electromagnetic induction, an alternating electromotive force is induced and output on the power-harvesting coil; real-time acquisition of the transmission conductor current and DC bus voltage, and determination of whether the inspection robot is currently in a normal travel mode or an obstacle-crossing magnetic circuit opening / closing mode; when determined to be in a normal travel mode, selecting one of the following three power-harvesting modes to execute based on the magnitude of the transmission conductor current: If the current in the transmission conductor is lower than the low current threshold, the control multi-winding switching module selects the power-collecting winding with more turns to reduce the power-collecting start threshold. If the current in the transmission line is between the low current threshold and the high current threshold, maximum power point tracking can be achieved by adjusting the input impedance of the rectifier circuit. If the current in the transmission line is higher than the high current threshold, the unloading branch is connected and the input impedance is adjusted to perform virtual impedance matching to prevent core saturation. When the obstacle-crossing magnetic circuit is determined to be in an opening or closing condition, before the power-taking component of the openable magnetic circuit is opened, the onboard energy storage unit is controlled to inject compensation power into the DC bus to keep the DC bus voltage stable during the period when the magnetic circuit is completely disconnected, ensuring that the patrol robot can continue to operate without power; and after the magnetic circuit is closed again, the power-taking mode of the aforementioned normal travel condition is restored.

[0005] By monitoring the transmission line current in real time and utilizing the principle of electromagnetic induction, the system switches between different electrical topologies and control strategies under varying current amplitudes to achieve efficient energy harvesting over a wide range. Particularly effective in power outage paths caused by mechanical obstacle crossing, the physical characteristics of energy storage components are used for energy buffering. In practice, a power harvesting component containing two semi-toroidal magnetic cores is installed on the robot, with coils wound around it. When closed, these cores form a magnetic circuit inducing current. The control system collects the conductor current and bus voltage in real time to determine whether the robot is moving normally or crossing an obstacle. When the conductor current is low, the switching module connects to a winding with more turns to lower the energy harvesting threshold and ensure that even microcurrents can generate electricity. When the current is moderate, the input impedance of the rectifier circuit is adjusted to ensure the system operates under the most ideal load condition, maximizing energy capture efficiency. When the current is too high, the unloading branch is activated and virtual impedance matching is performed to prevent the magnetic cores from saturating and failing due to excessive magnetic flux. Once an obstacle crossing command is received, the control system predicts the magnetic circuit disconnection time and pre-commands the energy storage unit to inject compensating power into the bus to fill the energy vacuum during mechanical movement. Normal power harvesting is automatically restored after the magnetic circuit closes. It achieves stable power supply covering all operating conditions (3A-1000A), completely solving the pain points of traditional energy extraction that fails to start at low current and is prone to saturation at high current.

[0006] Furthermore, the semi-toroidal magnetic core employs a composite core material, composed of a high-permeability material and an anti-saturation material in a predetermined ratio. This design ensures sensitivity at low currents while suppressing core saturation under high currents. Utilizing the design concept of composite materials, the strong magnetic focusing ability of high-permeability materials is combined with the permeability temperature stability and high saturation point of anti-saturation materials, achieving complementary performance through physical composite processing. During the manufacturing of the semi-toroidal magnetic core, high-permeability materials (such as ferrite) and anti-saturation materials (such as silicon steel sheets or amorphous alloys) are mixed and pressed or bonded together in a specific volume ratio. During robot operation, this composite magnetic core exhibits high permeability at low currents to enhance sensitivity, while under high currents, the anti-saturation component suppresses deep magnetic circuit saturation. While ensuring sensitivity at low currents, this effectively broadens the linear operating range of the magnetic core, avoids magnetic saturation caused by extreme conditions, and extends the service life of the power extraction components.

[0007] Furthermore, the virtual impedance matching specifically involves: adjusting the equivalent input impedance of the power extraction coil by controlling the duty cycle of the voltage-source pulse-width modulation rectifier, so that the secondary compensation capacitor and the core excitation inductor are in a resonant state. Based on AC circuit resonance theory and the maximum power transfer theorem, a load impedance conjugately matched with the internal impedance of the power supply is artificially constructed using power electronics technology, eliminating reactive power and making the equivalent input impedance of the power extraction coil purely resistive and numerically optimal. The control system sends a specific pulse width modulation signal (duty cycle command) to the voltage-source pulse-width modulation rectifier. The rectifier dynamically adjusts its equivalent input impedance so that the circuit formed by it, the secondary compensation capacitor, and the core excitation inductor reaches a resonant state. At this time, the power factor of the system is close to 1, and the energy transmission loss is minimized. Maximum power transmission can be achieved under a wide range of conductor current fluctuations; the grid-side current distortion caused by reactive power is effectively suppressed, protecting the safe and stable operation of the transmission line.

[0008] Furthermore, the multi-winding switching module includes at least two power-harvesing windings with different numbers of turns and corresponding semiconductor switches. The control unit selects the winding with the corresponding number of turns based on the relationship between the transmission line current and a preset threshold, so as to output stable power within a conductor current range of three amperes to one thousand amperes. Applying the transformer ratio adjustment principle, the effective number of turns of the power-harvesting coil in the circuit is changed to adjust the magnitude of the induced electromotive force and the internal resistance of the power-harvesting coil, thereby adapting to different intensities of the transmission line magnetic field. In implementation, the multi-winding switching module integrates at least two sets of coil taps with different numbers of turns, each set of taps connected in series with a semiconductor switch (such as a MOSFET or IGBT). The control unit logically selects the corresponding switch based on the real-time detected conductor current, connecting the appropriate tap to the subsequent rectifier circuit. This achieves adaptive ratio adjustment of the power-harvesting system, ensuring that sufficient voltage can be induced to start the system even under extremely low current, and outputting maximum power under medium current, significantly widening the lower limit of the effective power harvesting current.

[0009] Furthermore, it also includes: when the DC bus voltage is detected to exceed the safety limit, the power switch in the unloading branch is turned on to dissipate excess power in the unloading resistor. This employs the principle of active power dissipation. When the electrical energy generated by the system exceeds the total demand of the load and energy storage system, the excess electrical energy is converted into heat energy by a solid-state switch to maintain the absolute stability of the DC bus voltage. The detection unit monitors the DC bus voltage in real time. When the voltage exceeds the preset safety limit due to excessive power extraction, the control unit drives the power switch in the unloading branch to turn on, connecting the unloading resistor connected in parallel to the bus, releasing the excess power as heat. This provides reliable overvoltage protection and overload buffering capability for the system, preventing damage to downstream precision electronic equipment due to excess energy and ensuring the electrical safety of the robot control system.

[0010] Furthermore, the airborne energy storage unit includes a battery pack and a supercapacitor pack, both connected in parallel to the DC bus via a dual-channel DC-DC converter. The supercapacitor pack responds to the instantaneous impact of the compensation power. Based on power decoupling theory, the high power density of the supercapacitor and the high energy density of the battery are utilized to complement each other. The airborne energy storage unit consists of a traditional battery pack and a supercapacitor pack, both connected in parallel to the DC bus via a dual-channel DC-DC converter. During normal energy extraction, both store energy together or supply power directly; during obstacle crossing, the supercapacitor pack, due to its extremely fast charge and discharge rate, is specifically designed to handle the instantaneous impact of the compensation power. This optimizes the robot's energy storage structure. The supercapacitor effectively resolves the contradiction between instantaneous high-power output and the lifespan degradation of the battery due to high-current charge and discharge, improving the overall cycle life and instantaneous response speed of the energy storage system.

[0011] Furthermore, the DC bus voltage is continuously monitored during the magnetic circuit opening phase, and the discharge power of the supercapacitor bank is dynamically adjusted accordingly to maintain bus voltage stability in a closed-loop manner. A closed-loop feedback control algorithm is employed. In the event of a power outage due to the loss of external power input, the bus voltage is maintained constant by the dynamic discharge of the energy storage unit. During the period when external power is interrupted due to magnetic circuit opening, the control unit continuously samples the DC bus voltage. Based on the deviation between the actual voltage and the target rated voltage, the discharge current of the supercapacitor bank is dynamically adjusted in real time, forming a negative feedback closed loop. Compared to simple open-loop discharge, closed-loop control can more accurately maintain the bus voltage ripple within a very small range, ensuring the robot's motion control accuracy and sensor stability during obstacle crossing.

[0012] Furthermore, the mechanical action time required for the openable magnetic circuit power extraction component to completely disconnect from the point of issuing the opening command is dynamically estimated by the control unit based on the current driving voltage of the magnetic circuit opening and closing mechanism and the historical action duration, and the advance amount of the injected compensation power is determined accordingly. Based on the dynamic modeling and predictive control of the mechatronic system, considering that the mechanical action time is affected by factors such as voltage, temperature, and wear, real-time state parameters are used for dynamic estimation instead of a fixed delay. At the moment the opening command is issued, the control unit reads the current driving voltage of the magnetic circuit opening and closing mechanism and, combined with the action duration data recorded in the historical operation of the mechanism, calculates the estimated complete disconnection time. This time point is used as the reference for triggering the compensation power injection. This improves the accuracy of the energy replenishment action and avoids premature (wasting energy) or late (causing voltage drop) energy replenishment due to mechanical jamming or voltage fluctuations, achieving intelligent adaptive control.

[0013] Furthermore, this includes: setting up a communication module to upload transmission line current, DC bus voltage, power extraction coil output power, and energy storage unit state of charge to a remote monitoring platform, and receiving power extraction strategy parameters from the platform for adaptive adjustment. Relying on wireless communication technology and cloud computing power, a remote monitoring and distributed control system is constructed. The robot's communication module packages and uploads core operating data (conductor current, bus voltage, power extraction, battery power, etc.) to the remote monitoring platform. The platform sends optimal power extraction strategy parameters (such as threshold adjustment, power limitation, etc.) based on the overall operating status of all robots in the network, which the robots receive and execute. This enables remote health management and energy efficiency optimization of a large-scale line inspection robot cluster. Maintenance personnel can monitor equipment status without leaving their offices and remotely adjust power extraction strategies according to real-time grid conditions, greatly improving the level of intelligent operation and maintenance.

[0014] A power supply system for a line-following robot, used to perform the above-described method, includes: The openable magnetic circuit power extraction component is arranged around the power transmission line and integrated into the walking wheel bracket or end effector claw of the line inspection robot.

[0015] The power-taking coil is wound on the magnetic core of the openable and closable magnetic circuit power-taking component.

[0016] The multi-winding switching module is connected to multiple taps of the power-taking coil.

[0017] The rectifier and DC-DC converter circuit is connected to the output terminal of the power extraction coil.

[0018] The airborne energy storage unit includes a battery pack and a supercapacitor pack connected in parallel to the DC bus via a dual-channel DC-DC converter.

[0019] The unloading branch is connected in parallel to the DC bus.

[0020] The detection unit collects conductor current, bus voltage, and output power.

[0021] The control unit is linked to the multi-winding switching module, rectifier and DC-DC converter circuit, onboard energy storage unit, unloading branch, detection unit, and the walking motor and obstacle-crossing control mechanism of the line-following robot, and is configured to execute the above-described method steps. When the control unit receives the magnetic circuit opening command from the obstacle-crossing control mechanism, it first triggers the supercapacitor bank to pre-discharge. Only after the DC bus voltage is raised to a pre-charge level that is 5% to 10% higher than the rated value is the magnetic circuit opening and closing actuator allowed to operate.

[0022] The beneficial effects of this invention are as follows: Through the coordinated control of multi-winding switching and virtual impedance matching, this invention completely solves the problems of traditional CT power extraction, such as difficulty in starting up under low current and easy saturation under high current, achieving efficient and stable power extraction within the conductor current range of 3A to 1000A. Utilizing the high-rate discharge characteristics of the supercapacitor bank, pre-energy replenishment is performed before the magnetic circuit is disconnected. Through the mechanism of prediction, pre-charging, and compensation, the energy vacuum period during mechanical obstacle crossing is perfectly filled, reducing the risk of system power outage to zero and greatly improving the robot's obstacle crossing success rate and operational reliability. The control unit can dynamically estimate the mechanical action time based on real-time operating conditions and adjust the compensation power in a closed loop. The entire system has strong adaptive capabilities and requires no manual intervention. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a schematic diagram of the conventional travel mode structure of the present invention; Figure 3 This is a schematic diagram of the virtual impedance matching process of the present invention; Figure 4 This is a schematic diagram of the system architecture of the present invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings. It should be noted that this is only for the purpose of more clearly illustrating and explaining the present invention.

[0025] like Figure 1 As shown, this embodiment discloses an energy supply method for a power transmission line inspection robot based on electromagnetic induction, which includes the following steps: setting an openable and closable magnetic circuit power harvesting component on the inspection robot, the openable and closable magnetic circuit power harvesting component includes two semi-ring magnetic cores and a power harvesting coil wound on the magnetic cores. When the two semi-ring magnetic cores are closed, they form a closed magnetic circuit around the power transmission conductor. Based on the principle of electromagnetic induction, an alternating electromotive force is induced and output on the power harvesting coil; the current of the power transmission conductor and the DC bus voltage are collected in real time, and the inspection robot is determined to be in a normal travel condition or an obstacle-crossing magnetic circuit opening and closing condition.

[0026] Power input terminal: An open-type current transformer (CT) structure is adopted to facilitate the robot's obstacle crossing. The power input coil has three taps, each corresponding to a different turns ratio.

[0027] The power electronic conversion terminal includes a three-phase full-bridge PWM rectifier and a bidirectional DC-DC converter. The PWM rectifier is responsible for virtual impedance matching and power factor correction; the bidirectional DC-DC converter is responsible for bus voltage regulation.

[0028] Load / Energy Storage Side: The DC bus connects the robot's main control system, drive motors, and a hybrid energy storage system (HESS) consisting of a supercapacitor and a lithium battery connected in parallel. The supercapacitor is designed with sufficient capacity to support the energy required for the robot to complete one of its longest obstacle-crossing maneuvers.

[0029] Wide current graded energy harvesting control process: Low-current startup test: Assume the current circuit is unloaded, with a conductor current of only 2 amps. The control unit detects that this current is below a set low threshold (e.g., 5 amps) and sends a signal to the semiconductor switch of the multi-winding switching module, turning on the switch connected to the "multi-turn tap". At this time, the equivalent number of turns of the power-taking coil increases, and even with a current of 2 amps, a sufficiently high voltage can be induced, successfully waking up the robot system.

[0030] Full-load operation test: When the line delivers high-power electrical energy, the conductor current surges to 800 amperes. The control unit recognizes the high-current condition and activates the power switch in the unloading branch. Simultaneously, the PWM rectifier enters virtual impedance matching mode, adjusting the duty cycle to ensure the equivalent input impedance of the power extraction coil is purely resistive and optimally matched with the source impedance. At this time, the magnetic core always operates in the linear region without saturation, and excess energy is safely dissipated as heat through the unloading resistor.

[0031] Seamless obstacle-crossing power replenishment control process: When the robot navigation system plans its path and prepares to cross a tension tower, the obstacle crossing control mechanism sends a "magnetic circuit is about to open" command to the energy system.

[0032] After receiving the command, the control unit does not immediately disconnect the magnetic circuit. Instead, it first queries the driving voltage and historical action duration of the current magnetic circuit opening and closing mechanism, and dynamically estimates the mechanical action time (denoted as T) required from the issuance of the command to the complete disconnection of the magnetic circuit.

[0033] Before time T arrives, the control unit sends a discharge command to the supercapacitor bank in the onboard energy storage unit. The supercapacitor bank rapidly injects compensation power into the DC bus through a bidirectional DC-DC converter.

[0034] Throughout the process of the magnetic circuit gradually opening until it is completely separated from the wire, the bus voltage not only does not drop, but may even rise slightly due to the injection of the supercapacitor, maintaining the normal operation of all the robot's sensors and servo motors.

[0035] After the magnetic circuit is reclosed, the power extraction coil generates electricity again. The control unit cuts off the discharge circuit of the supercapacitor, and the system smoothly transitions back to the conventional rectification power extraction mode.

[0036] like Figure 2 As shown, when the operation is determined to be under normal travel conditions, one of the following three power extraction modes is selected based on the magnitude of the transmission line current: If the current in the transmission conductor is lower than the low current threshold, the control multi-winding switching module selects the power-collecting winding with more turns to reduce the power-collecting start threshold. If the current in the transmission line is between the low current threshold and the high current threshold, maximum power point tracking can be achieved by adjusting the input impedance of the rectifier circuit. If the current in the transmission line is higher than the high current threshold, the unloading branch is connected and the input impedance is adjusted to perform virtual impedance matching to prevent core saturation. When the obstacle-crossing magnetic circuit is determined to be in an opening or closing condition, before the power-taking component of the openable magnetic circuit is opened, the onboard energy storage unit is controlled to inject compensation power into the DC bus to keep the DC bus voltage stable during the period when the magnetic circuit is completely disconnected, ensuring that the patrol robot can continue to operate without power; and after the magnetic circuit is closed again, the power-taking mode of the aforementioned normal travel condition is restored.

[0037] By monitoring the transmission line current in real time and utilizing the principle of electromagnetic induction, the system switches between different electrical topologies and control strategies under varying current amplitudes to achieve efficient energy harvesting over a wide range. Particularly effective in power outage paths caused by mechanical obstacle crossing, the physical characteristics of energy storage components are used for energy buffering. In practice, a power harvesting component containing two semi-toroidal magnetic cores is installed on the robot, with coils wound around it. When closed, these cores form a magnetic circuit inducing current. The control system collects the conductor current and bus voltage in real time to determine whether the robot is moving normally or crossing an obstacle. When the conductor current is low, the switching module connects to a winding with more turns to lower the energy harvesting threshold and ensure that even microcurrents can generate electricity. When the current is moderate, the input impedance of the rectifier circuit is adjusted to ensure the system operates under the most ideal load condition, maximizing energy capture efficiency. When the current is too high, the unloading branch is activated and virtual impedance matching is performed to prevent the magnetic cores from saturating and failing due to excessive magnetic flux. Once an obstacle crossing command is received, the control system predicts the magnetic circuit disconnection time and pre-commands the energy storage unit to inject compensating power into the bus to fill the energy vacuum during mechanical movement. Normal power harvesting is automatically restored after the magnetic circuit closes. It achieves stable power supply covering all operating conditions (3A-1000A), completely solving the pain points of traditional energy extraction that fails to start at low current and is prone to saturation at high current.

[0038] The semi-toroidal magnetic core employs a composite core material, composed of a high-permeability material and an anti-saturation material in a predetermined ratio. This composite material is used to suppress core saturation under high current while ensuring sensitivity at low currents. Utilizing the design concept of composite materials, it combines the strong magnetic focusing ability of high-permeability materials with the permeability temperature stability and high saturation point of anti-saturation materials, achieving complementary performance through physical composite bonding. During the manufacturing of the semi-toroidal core, high-permeability materials (such as ferrite) and anti-saturation materials (such as silicon steel sheets or amorphous alloys) are mixed and pressed or bonded together in a specific volume ratio. During robot operation, this composite core exhibits high permeability at low currents to enhance sensitivity, while under high currents, the anti-saturation component suppresses deep magnetic circuit saturation. While ensuring sensitivity at low currents, this effectively broadens the linear operating range of the core, avoids magnetic saturation caused by extreme conditions, and extends the service life of the power harvesting components.

[0039] like Figure 3 As shown, the virtual impedance matching specifically involves controlling the duty cycle of the voltage-source pulse-width modulation rectifier to adjust the equivalent input impedance of the power extraction coil, thereby bringing the secondary compensation capacitor and the core excitation inductor into a resonant state. Based on AC circuit resonance theory and the maximum power transfer theorem, a load impedance conjugately matched to the internal impedance of the power supply is artificially constructed using power electronics technology. This eliminates reactive power and makes the equivalent input impedance of the power extraction coil purely resistive and optimally valued. The control system sends a specific pulse width modulation signal (duty cycle command) to the voltage-source pulse-width modulation rectifier. The rectifier dynamically adjusts its equivalent input impedance to achieve resonance with the circuit formed by the secondary compensation capacitor and the core excitation inductor. At this point, the system's power factor is close to 1, and energy transfer loss is minimized. Maximum power transfer can be achieved under a wide range of conductor current fluctuations; effectively suppressing grid-side current distortion caused by reactive power and protecting the safe and stable operation of transmission lines.

[0040] The multi-winding switching module includes at least two power-harvesing windings with different numbers of turns and corresponding semiconductor switches. The control unit selects the winding with the corresponding number of turns based on the relationship between the transmission line current and a preset threshold, ensuring stable power output within a conductor current range of three to one thousand amperes. Applying the transformer ratio adjustment principle, the effective number of turns of the power-harvesting coil in the circuit is changed to adjust the magnitude of the induced electromotive force and the internal resistance of the power-harvesting coil, thereby adapting to different intensities of the transmission line magnetic field. In implementation, the multi-winding switching module integrates at least two sets of coil taps with different numbers of turns, each set of taps connected in series with a semiconductor switch (such as a MOSFET or IGBT). The control unit logically selects the corresponding switch based on the real-time detected conductor current, connecting the appropriate tap to the subsequent rectifier circuit. This achieves adaptive ratio adjustment of the power-harvesting system, ensuring sufficient voltage to start the system even under extremely low current, and maximum power output under moderate current, significantly widening the effective current limit for power harvesting.

[0041] In this embodiment, the system further includes: when the DC bus voltage exceeds the safety limit, driving the power switch in the unloading branch to conduct, dissipating excess power in the unloading resistor. This employs the principle of active power dissipation. When the electrical energy generated by the system exceeds the total demand of the load and energy storage system, the excess electrical energy is converted into heat energy by a solid-state switch to maintain the absolute stability of the DC bus voltage. The detection unit monitors the DC bus voltage in real time. When the voltage exceeds the preset safety limit due to excessive power extraction, the control unit drives the power switch in the unloading branch to conduct, connecting the unloading resistor connected in parallel to the bus, releasing the excess power as heat. This provides reliable overvoltage protection and overload buffering capability for the system, preventing damage to downstream precision electronic equipment due to excess energy and ensuring the electrical safety of the robot control system.

[0042] The airborne energy storage unit comprises a battery bank and a supercapacitor bank, both connected in parallel to the DC bus via a dual-channel DC-DC converter. The supercapacitor bank responds to the instantaneous impact of the compensation power. Based on power decoupling theory, the high power density of the supercapacitor and the high energy density of the battery are utilized to complement each other. The airborne energy storage unit consists of a traditional battery bank and a supercapacitor bank, both connected in parallel to the DC bus via a dual-channel DC-DC converter. During normal energy extraction, both banks jointly store energy or directly supply power; during obstacle crossing, the supercapacitor bank, due to its extremely fast charge and discharge rate, is specifically designed to handle the instantaneous impact of the compensation power. This optimizes the robot's energy storage structure. The supercapacitor effectively resolves the contradiction between instantaneous high-power output and the lifespan degradation of the battery due to high-current charge and discharge, improving the overall cycle life and instantaneous response speed of the energy storage system.

[0043] During the magnetic circuit opening phase, the DC bus voltage is continuously monitored, and the discharge power of the supercapacitor bank is dynamically adjusted accordingly to maintain bus voltage stability in a closed-loop manner. A closed-loop feedback control algorithm is employed. In the event of a power outage due to the loss of external power input, the bus voltage is maintained constant by the dynamic discharge of the energy storage unit. During periods of power interruption caused by magnetic circuit opening, the control unit continuously samples the DC bus voltage. Based on the deviation between the actual voltage and the target rated voltage, the discharge current of the supercapacitor bank is dynamically adjusted in real time, forming a negative feedback closed loop. Compared to simple open-loop discharge, closed-loop control can more accurately maintain bus voltage ripple within a minimal range, ensuring the robot's motion control accuracy and sensor stability during obstacle crossing.

[0044] The mechanical action time required for the openable magnetic circuit power extraction component to completely disconnect from the point of issuing the opening command is dynamically estimated by the control unit based on the current driving voltage of the magnetic circuit opening and closing mechanism and historical action durations, and the advance amount of injected compensation power is determined accordingly. Based on dynamic modeling and predictive control of the mechatronic system, considering the influence of factors such as voltage, temperature, and wear on the mechanical action time, real-time state parameters are used for dynamic estimation, rather than a fixed delay. At the moment the opening command is issued, the control unit reads the current driving voltage of the magnetic circuit opening and closing mechanism and, combined with the action duration data recorded in the mechanism's historical operation, calculates the estimated complete disconnection time. This time point is used as the reference for triggering compensation power injection. This improves the accuracy of the energy replenishment action, avoids premature (wasting energy) or premature (leading to voltage drop) energy replenishment due to mechanical jamming or voltage fluctuations, and achieves intelligent adaptive control.

[0045] In this embodiment, the system further includes: a communication module that uploads transmission line current, DC bus voltage, power extraction coil output power, and energy storage unit state of charge to a remote monitoring platform, and receives power extraction strategy parameters from the platform for adaptive adjustment. Leveraging wireless communication technology and cloud computing power, a remote monitoring and distributed control system is constructed. The robot's communication module packages and uploads core operating data (conductor current, bus voltage, power extraction, battery charge, etc.) to the remote monitoring platform. The platform sends optimal power extraction strategy parameters (such as threshold adjustment, power limitation, etc.) based on the overall operating status of all robots in the network, which the robots receive and execute. This enables remote health management and energy efficiency optimization of a large-scale line inspection robot cluster. Maintenance personnel can monitor equipment status without leaving their offices and remotely adjust power extraction strategies based on real-time grid conditions, greatly improving the level of intelligent operation and maintenance.

[0046] like Figure 4 As shown, a power supply system for a line-following robot, used to perform the above-described method, includes: The openable magnetic circuit power extraction component is arranged around the power transmission line and integrated into the walking wheel bracket or end effector claw of the line inspection robot.

[0047] The power-taking coil is wound on the magnetic core of the openable and closable magnetic circuit power-taking component.

[0048] The multi-winding switching module is connected to multiple taps of the power-taking coil.

[0049] The rectifier and DC-DC converter circuit is connected to the output terminal of the power extraction coil.

[0050] The airborne energy storage unit includes a battery pack and a supercapacitor pack connected in parallel to the DC bus via a dual-channel DC-DC converter.

[0051] The unloading branch is connected in parallel to the DC bus.

[0052] The detection unit collects conductor current, bus voltage, and output power.

[0053] The control unit is linked to the multi-winding switching module, rectifier and DC-DC converter circuit, onboard energy storage unit, unloading branch, detection unit, and the walking motor and obstacle-crossing control mechanism of the line-following robot, and is configured to execute the above-described method steps. When the control unit receives the magnetic circuit opening command from the obstacle-crossing control mechanism, it first triggers the supercapacitor bank to pre-discharge. Only after the DC bus voltage is raised to a pre-charge level that is 5% to 10% higher than the rated value is the magnetic circuit opening and closing actuator allowed to operate.

[0054] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A power supply method for a power transmission line inspection robot based on electromagnetic induction, characterized in that, Includes the following steps: An openable magnetic circuit power-taking component is installed on the line inspection robot. The openable magnetic circuit power-taking component includes two semi-ring magnetic cores and a power-taking coil wound on the magnetic cores. When the two semi-ring magnetic cores are closed, they form a closed magnetic circuit around the power transmission line. Based on the principle of electromagnetic induction, an alternating electromotive force is induced and output on the power-taking coil. The system collects real-time data on the transmission line current and DC bus voltage, and determines whether the inspection robot is currently in normal travel mode or obstacle-crossing magnetic circuit opening / closing mode. When determined to be in normal travel mode, it selects one of the following three power supply modes to execute based on the magnitude of the transmission line current: If the current in the transmission conductor is lower than the low current threshold, the control multi-winding switching module selects the power-collecting winding with more turns to reduce the power-collecting start threshold. If the current in the transmission line is between the low current threshold and the high current threshold, maximum power point tracking can be achieved by adjusting the input impedance of the rectifier circuit. If the current in the transmission line is higher than the high current threshold, the unloading branch is connected and the input impedance is adjusted to perform virtual impedance matching to prevent core saturation. When the obstacle-crossing magnetic circuit is determined to be in an opening or closing condition, before the power-taking component of the openable magnetic circuit is opened, the onboard energy storage unit is controlled to inject compensation power into the DC bus to keep the DC bus voltage stable during the period when the magnetic circuit is completely disconnected, ensuring that the patrol robot can continue to operate without power; and after the magnetic circuit is closed again, the power-taking mode of the aforementioned normal travel condition is restored.

2. The energy supply method for the transmission line inspection robot based on electromagnetic induction according to claim 1, characterized in that, The semi-ring core uses a composite core material, which is composed of high permeability material and anti-saturation material in a preset ratio, in order to suppress core saturation under high current while ensuring low current energy harvesting sensitivity.

3. The power supply method for the transmission line inspection robot based on electromagnetic induction according to claim 1, characterized in that, The virtual impedance matching specifically involves adjusting the equivalent input impedance of the power extraction coil by controlling the duty cycle of the voltage-type pulse width modulation rectifier, so that the secondary compensation capacitor and the core excitation inductor are in a resonant state.

4. The power supply method for the transmission line inspection robot based on electromagnetic induction according to claim 1, characterized in that, The multi-winding switching module includes at least two power-taking windings with different numbers of turns and corresponding semiconductor switches. The control unit selects the winding with the corresponding number of turns according to the relationship between the current of the transmission line and a preset threshold, so as to output stable power in the range of three amperes to one thousand amperes of conductor current.

5. The energy supply method for the transmission line inspection robot based on electromagnetic induction according to claim 1, characterized in that, Also includes: When the DC bus voltage is detected to exceed the safety limit, the power switch in the drive unloading branch is turned on, dissipating the excess power to the unloading resistor.

6. The energy supply method for the transmission line inspection robot based on electromagnetic induction according to claim 1, characterized in that, The airborne energy storage unit includes a battery pack and a supercapacitor pack, which are connected in parallel to the DC bus via a dual DC-DC converter, and the supercapacitor pack responds to the instantaneous impact of the compensation power.

7. The energy supply method for the transmission line inspection robot based on electromagnetic induction according to claim 6, characterized in that, During the magnetic circuit opening period, the DC bus voltage is continuously monitored, and the discharge power of the supercapacitor bank is dynamically adjusted accordingly to maintain the bus voltage stability in a closed-loop manner.

8. The energy supply method for the transmission line inspection robot based on electromagnetic induction according to claim 1, characterized in that, The mechanical action time required for the openable magnetic circuit power extraction component to completely disconnect the magnetic circuit from the issuance of the opening command is dynamically estimated by the control unit based on the current driving voltage of the magnetic circuit opening and closing mechanism and the historical action time, and the advance amount of the injected compensation power is determined accordingly.

9. The power supply method for the transmission line inspection robot based on electromagnetic induction according to claim 1, characterized in that, Also includes: The communication module is configured to upload the transmission line current, DC bus voltage, power extraction coil output power, and energy storage unit charge status to the remote monitoring platform, and to receive power extraction strategy parameters from the platform for adaptive adjustment.

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