138 results about "Series compensation" patented technology

The invention provides a strong series compensation grid-connected stability regulation and control method of a grid-forming type energy storage converter and a related device, and belongs to the technical field of grid connection of a power grid. According to the method, a three-phase grid-connected inverter complete sequence impedance model controlled by the virtual synchronous generator is established by using a harmonic linearization method, and reasons for causing subsynchronous oscillation by using a double-closed-loop control strategy are analyzed. In order to improve the grid-connected stability of a strong series compensation power grid of a grid-forming type energy storage converter, a PI-LADRC control strategy is provided, a sequence impedance model under the control mode is established, and grid-connected stability margin information under the PI-LADRC control strategy is obtained by comparing output impedance characteristics of a grid-connected inverter under a double closed-loop control mode and a PI-LADRC control mode. According to the invention, the PI-LADRC control strategy is adopted, so that the grid-connected stability can be effectively regulated and controlled.

Systems and method to minimize conditions that cause sub-synchronous oscillation (SSOs) associated with series compensated transmission grids. The implementations ensures the correct development of methods and systems that can mitigate sub-synchronous oscillation (SSOs) associated with a series compensated transmission grid and enhance the series compensation efficiency. An example implementation is a network-based SSO mitigation technology, and another example implementation is a generator-based SSO mitigation technology. The discovery and example implementations are applicable to series compensated transmission networks with synchronous generators, induction generators, wind turbines, solar photovoltaic generators, charging stations, battery storage systems, high-voltage DC transmission systems, STATCOMs, inverter-based data centers, and other inverter-based resources.

The invention belongs to the technical field of power systems, and particularly relates to a power grid impedance simulation device, a design method and a use method.The design of the device comprises the steps that the types of needed components are determined, and the number of the components and electrical parameter values are obtained according to the actual national standard in combination with the minimum component number criterion; all components are connected according to needs, and a controller is adopted to realize corresponding control so as to support working condition simulation and switching of different short circuit ratios and series compensation degrees; a switch logic control program is set in the controller, so that when the controller receives a power grid working condition switching instruction, switching of working conditions corresponding to the power grid short-circuit ratio and the series compensation degree is achieved by executing the preset switch logic control program. According to the technical scheme, through the integrated design of parameter calculation, hardware topology and logic control, the problems of low test efficiency, poor simulation precision and high cost in the prior art are solved, and an efficient, accurate and economical solution is provided for the adaptability test of the new energy converter under a double-high power system.

The invention relates to the technical field of controllable series compensation, in particular to a power distribution area voltage rapid compensation device and compensation method based on controllable series compensation, and the method comprises the steps: collecting various monitoring data of each phase of each key node of a power distribution area in real time; obtaining each sub-time period of each monitoring data of each phase; acquiring a change correlation value and a deviation change characteristic value of various monitoring data of each phase in each sub-time period; comparing the deviation change characteristic values of various monitoring data between each phase and each of the other phases of the key node where the phase is located so as to obtain a dynamic change factor of the various monitoring data of each phase at each moment and obtain an influence weight and a voltage characteristic value of each phase of each key node at each moment; and compensating the voltage of the power distribution area based on a controllable series compensation technology. According to the method, the trigger angle in the voltage compensation process is accurately determined by accurately evaluating the voltage deviation of each key node, and the accuracy of voltage compensation of the power distribution area is improved.

The invention discloses a series compensation control method and control system for a dual-active bridge converter, and belongs to the technical field of direct current converter control, and the series compensation control method comprises the steps: determining a current working mode corresponding to a kth beat, calculating a series compensation coefficient of the kth beat in the current working mode by using the voltage transmission ratio of the kth beat, the actual battery current, the control phase shift angle of the previous beat and the duty ratio of the input bus side of the previous beat, and inputting a middle phase shift angle of the kth beat into a series compensation link of the kth beat to obtain a control phase shift angle of the kth beat, and finally, generating a kth-beat driving signal by using the kth-beat control phase shift angle and the kth-beat input bus side duty ratio so as to drive a power switch device of the dual-active bridge converter. The series compensation link can dynamically adjust and expand the working characteristics of the phase-shifted dual-active bridge converter under different working conditions, so that the defect of poor dynamic adaptive capacity of a traditional PI control surface to a wide load range can be overcome.

The present application belongs to the field of flexible AC transmission and distribution and power electronics, and discloses a unified power quality conditioner and method to achieve the goal of power quality management. The device comprises a DC bus and a compensation unit and a regulating unit connected thereto; the compensation unit comprises a series compensation subunit and a parallel compensation subunit; the series compensation subunit is used for compensating the load voltage; the DC bus is used for providing compensation energy for the series compensation subunit; the parallel compensation subunit is used for compensating the load harmonic, three-phase imbalance and reactive current, and also used for providing voltage support for the DC bus and energy for the series compensation subunit; the regulating unit comprises a parallel super capacitor energy storage system and a photovoltaic power generation system; the super capacitor energy storage system comprises a super capacitor and a first DC / DC converter; the photovoltaic power generation system comprises a photovoltaic array and a second DC / DC converter. The present application solves the coupling problem of the series and parallel inverters of the device, and makes the DC side bus voltage stable.

The invention discloses a method and a system for suppressing subsynchronous oscillation of a virtual synchronous doubly-fed wind turbine connected to the grid through series compensation. The method includes: obtaining an expression of the output impedance of the grid-side converter based on VSG; revealing the positive damping characteristic of the grid-side converter based on VSG for subsynchronous oscillation from the perspective of the equivalent impedance of the doubly-fed wind turbine grid-connected system; analyzing the mechanism of suppressing subsynchronous oscillation of the virtual synchronous doubly-fed wind turbine grid-connected system in combination with active disturbance rejection control; and constructing an improved active disturbance rejection controller to suppress subsynchronous oscillation. The subsynchronous oscillation analysis method adopted by the invention has a certain universality and can provide a theoretical analysis basis for the subsynchronous oscillation problem caused by a high proportion of power electronic devices participating in the new energy power generation system. At the same time, the suppression method proposed by the invention is not only applicable to doubly-fed generating units, but also applicable to suppressing subsynchronous oscillation in direct-drive wind turbines and weak AC systems extended thereto.

The embodiment of the invention discloses a control method for suppressing subsynchronous oscillation of a doubly-fed fan and related equipment, relates to the technical field of stable control of a power system, and directly estimates subsynchronous frequency based on inherent parameters such as series compensation capacitance reactance, equivalent inductive reactance and power grid synchronous frequency. The influence of the power grid resistance parameter change on the sub-synchronous frequency estimation value is eliminated; quickly locking a spectrum analysis range based on the obtained subsynchronous frequency estimation value; according to the method, the oscillation frequency, namely the subsynchronous resonant frequency, is accurately locked through fast Fourier decomposition of the rotor current in combination with an amplitude comparison strategy in a preset spectral analysis range, and the subsynchronous resonant frequency in a doubly-fed fan rotor side control system is filtered out, so that oscillation suppression is achieved.

The present application discloses a method for suppressing subsynchronous oscillations of a doubly-fed wind turbine and related equipment, belonging to the field of wind power generation technology. The method comprises: when the doubly-fed wind turbine is connected to the power grid via a series compensation capacitor, obtaining a voltage control signal of the doubly-fed wind turbine in a synchronous rotating coordinate system; using a filter to extract the voltage control signal within a specified frequency band, and using a phase shifter to perform phase shift compensation on the signal extracted by the filter with the goal of ensuring that the doubly-fed wind turbine satisfies the positive impedance characteristic within the specified frequency band; performing an inverse Park transform on the voltage control signal after phase shift compensation, and using the voltage control signal after the inverse Park transform to control the three-phase AC power output by the doubly-fed wind turbine. This method can solve the current technical problems of high cost, complex modeling, and difficulty in engineering application when suppressing subsynchronous oscillations of doubly-fed wind turbines.

The present invention relates to the field of wireless power transmission technology, and discloses a highly anti-offset wireless power transmission system with four reconstruction modes, comprising a reconfigurable inverter module, a primary-side compensation network module, a secondary-side compensation network module, and a rectifier filter circuit module; through the coordination of compensation topology reconstruction and parameter optimization design, constant power output within a coupling coefficient variation range of about 620% is achieved, and the secondary-side loop only uses a single capacitor series compensation. The system structure is more compact, simple, and lightweight, and is more in line with actual application requirements. It can achieve constant power output within a coupling coefficient variation range of about 620% at a fixed operating frequency and without the need for additional control hardware or complex mechanical adjustments, only through simple switch tube control.

The invention discloses a power grid operation mode voltage automatic adjustment method and system suitable for different new energy coincidence rates, and belongs to the technical field of power systems. According to the method, series compensation and parallel compensation of a plant station with an out-of-limit bus in a third power flow result are output, a capacitor is automatically input or reactance is automatically quitted from the plant station with the voltage exceeding the lower limit according to the difference between the voltage and the limit voltage, and a reactive power is automatically output from the plant station with the voltage exceeding the upper limit according to the difference between the voltage and the limit voltage. And the capacitor is automatically withdrawn or the reactance is input. According to the invention, under the condition that the voltage cannot be adjusted, surrounding reactive power resources can be automatically adjusted, the terminal voltage of a new energy machine is cooperatively adjusted, and the voltage of a high voltage level can be automatically switched to a target level through series-parallel compensation.

The invention belongs to the field of wireless electric energy transmission, and discloses a three-coil structure constant-current constant-voltage type wireless electric energy transmission system suitable for an office table, the system comprises an electric energy sending unit, a relay unit and a receiving unit, and the relay unit forms a series resonance network through a relay coil L2 and a relay series compensation capacitor C2; the receiving unit consists of a receiving coil L3, a receiving end compensation network, a rectifier D and a battery load R; the input end of the rectifier D is connected with the receiving coil L3, a constant current mode compensation capacitor C3CC and a constant voltage mode compensation capacitor C3CV which can be switched through a switch S are connected in series between the rectifier D and the receiving coil L3, and the output end of the rectifier is connected with a battery load R. The system can realize constant-current and constant-voltage output characteristics meeting battery charging requirements when the equivalent impedance of the battery is changed, and can ensure that the inverter realizes zero-phase-angle switching operation when the equivalent impedance of the battery is changed and the system is subjected to position offset.

An S2G charging station harmonic current detection and UPQC suppression method fusing wavelet transform and an LVQ neural network performs multi-scale decomposition on a current signal by using the wavelet transform, extracts time-frequency characteristics of different frequency bands, realizes real-time detection and classification of harmonic current in combination with the LVQ neural network, suppresses the harmonic current at the charging station side through a UPQC parallel compensation unit, and improves the harmonic current detection and UPQC suppression efficiency. The series compensation unit eliminates power grid side voltage harmonics. According to the method, high-precision harmonic current detection can be realized in the S2G charging station, harmonic current of different frequency bands can be quickly and accurately identified and classified, and amplitude and phase information of the harmonic current can be extracted, so that accurate analysis of the harmonic current is realized; through the dynamic compensation function of the UPQC, the harmonic current of the power grid and the charging station can be effectively suppressed, and the stability of the electric energy quality of the system is ensured. The method has efficient real-time detection and compensation capability, and can significantly reduce the negative influence of harmonic distortion on the power grid and the charging station.

The invention discloses a series compensation capacitor and PMU measurement tampering-based concealment attack method. The method comprises the following steps: S1, establishing a complete dynamic model of a grid-connected doubly-fed induction wind generator; s2, in order to improve the transmission capacity of the power transmission line and reduce the energy loss in the transmission process, the DFIG wind power plant is often connected with an external power grid through a series compensation line, and a series compensation line module differential equation is constructed; a PMU is installed at the machine end of each DFIG to obtain the electrical quantity; s3, providing a group of unstable feature roots, inversely solving a capacitance value corresponding to the feature value, and taking the capacitance value as an attack value of the capacitance in the step S2; and S4, calculating the variable quantity of the measured value caused by the attack, subtracting the measured variable quantity from the measured value after the system is attacked so as to obtain a normal measured value, and tampering the measured value of the PMU into a normal value on a transmission line so as to realize the hidden attack.

The application discloses a kind of second-order general type fast desaturation controller determination method and system, it is related to engineering system control field, this method includes: determining the saturation gain of actuator in target industrial control system;Using the input-output deviation of actuator, second-order general type fast integral desaturation compensator is constructed;Based on saturation gain, second-order general type fast integral desaturation compensator is equivalent into the desaturation structure of series compensation, and the compensation link and desaturation channel in desaturation structure are determined;Using the linkage relationship of bandwidth PID controller and desaturation bandwidth, the value of desaturation bandwidth in compensation link and desaturation channel is determined, to obtain the second-order general type fast desaturation controller of target industrial control system.The application can realize control while selecting less parameters, and improve the stability of control.

The utility model discloses a low pressure series compensation device relates to the technical field of compensation circuit, including the soft start power supply circuit for controlling starting current slow rise, the surge impact is suppressed, the capacitive reactive power output for the dynamic regulation series capacitor, the low pressure reactive power compensation circuit of compensation inductive load's reactive power shortage, the voltage detection circuit for real -time tracking circuit voltage fluctuation, generates the voltage feedback signal required for compensation control. The utility model discloses through the voltage detection circuit, thereby through the accurate detection of resistance voltage dividing network and operational amplifier IC1, realizes real -time monitoring and signal conditioning to the grid voltage, ensures that compensation system can accurately obtain voltage variation information, provides reliable data support for reactive power compensation control.

A static synchronous series compensation system and method, the scheme includes: a primary circuit installed on a high potential platform and a secondary circuit installed in a control protection room; the high potential platform is connected with a power transmission line at the same potential; the primary circuit is connected in series with the power transmission line to compensate the voltage of the power transmission line; the secondary circuit is connected with the primary circuit, and compensation instructions are issued to the primary circuit according to the voltage loss value of the power transmission line. The static synchronous series compensation system in the scheme does not need a series transformer or only needs a low insulation grade series transformer, greatly reduces the insulation design difficulty of the series transformer, reduces the device cost, reduces the equipment weight, reduces the equipment cost, and greatly reduces the occupied area. In the scheme, the high potential platform is connected with the power transmission line at the same potential, and the primary circuit is installed on the high potential platform, which reduces the energy loss of the primary circuit caused by corona discharge and the electromagnetic interference of the adjacent equipment.

The present invention discloses an autonomous coreless transformer and a refined design method thereof. The transformer comprises an autonomous voltage source, a circular winding bobbin, a primary winding, a secondary winding, a primary series compensation capacitor, a secondary series compensation capacitor, an uncontrolled rectifier module, an output filter capacitor, and a load resistor. The secondary winding is wound around the center of the circular winding bobbin, and the primary winding is evenly distributed on both sides of the secondary winding. Adjusting the number of turns and gap between the primary and secondary windings can control the transformer parameters. The present invention achieves refined design of the autonomous coreless transformer parameters by combining winding structure design with voltage deviation compensation.

The invention discloses a constant-current constant-voltage wireless power transmission system based on an integrated composite compensation topology, and belongs to the technical field of wireless power transmission, the constant-current constant-voltage wireless power transmission system comprises a transmitting end and a receiving end, the transmitting end comprises an H-bridge inversion module, a transmitting end controller, a primary side integrated LCCLC composite compensation network and a transmitting coil, and the receiving end comprises a receiving coil, a series compensation network and a full-bridge rectifier module. The compensation inductor L1 in the integrated LCCLC-S composite compensation and the transmitting end coil are coaxially and tightly installed in the same plane, so that the coupling effect between magnet exciting coils is enhanced; the switching between the LCC-S compensation structure and the LC-S compensation structure is realized through switch control; constraint conditions of composite compensation structure parameter design are further given, and the constant current output characteristic and the constant voltage output characteristic of the LC-S compensation state are achieved.

The invention relates to the field of current reducing systems, and particularly discloses a system and a method for reducing current and improving electric energy quality, comprising at least one current limiting module, a first current transformer, at least one capacitive module, a first switch, a second switch, a third switch, a fourth switch, a control protection system and a voltage transformer, the current limiting module is connected in series with the third switch, then connected in parallel with the fourth switch, and then integrally connected in series with the first current transformer; the capacitive module is connected in series with the second switch and then connected in parallel with the third switch; one end of the first switch is connected with the capacitive module and a connecting line of the second switch, and the other end of the first switch is grounded. Functions of current limiting, reactive compensation, series compensation, harmonic filtering and the like can be realized, and the number of equipment is reduced.

The invention discloses a method and device for calculating the defect rate of series compensation secondary equipment under different operation years, a medium and equipment. The method comprises the following steps: extracting a series compensation secondary equipment set and a series compensation secondary equipment defect set which meet a preset statistical condition; dividing the operating age limit into a plurality of continuous operating age limit units based on the division granularity of the operating age limit; traversing the series compensation secondary equipment in the series compensation secondary equipment set, determining operation age limit units covered by the life cycle of the series compensation secondary equipment according to the commissioning time and the back operation time of the series compensation secondary equipment, and adding 1 to an equipment number counter corresponding to each covered operation age limit unit; traversing equipment defects in the series compensation secondary equipment defect set, determining an operation age limit unit to which the equipment defects belong according to the operation age limit of the corresponding series compensation secondary equipment when the defects occur, and adding 1 to a defect number counter corresponding to the operation age limit unit; and for each operating age limit unit, calculating the defect rate of the operating age limit unit according to the corresponding defect number and equipment number.

The invention discloses a hybrid distribution transformer power electronic module capacity configuration method for load prediction. The method comprises the steps that the capacity of a series compensation module is calculated based on a target area load prediction value so as to represent the power processing capacity needed by voltage compensation; when the capacity of the parallel compensation module is determined, the capacity value of the series compensation module is multiplexed, so that a load fluctuation compensation task is cooperatively borne, and the capacity of the parallel compensation module is equal to the sum of the following two parts: a) the product of the capacity of the transformer in the transformer area and a fixed proportionality coefficient is used for representing a reactive power compensation demand proportion; b) the capacity value of the series compensation module; and selecting the series compensation module and the parallel compensation module of which the actual power processing capacity is not less than the calculation capacity.

The invention discloses a subsynchronous / supersynchronous oscillation characteristic-maintained wind power plant equivalent modeling method, which comprises the following steps of: constructing a frequency domain impedance model based on a doubly-fed fan series compensation grid-connected system; based on the frequency domain impedance model, the influence of the wind speed and the grid-connected distance on the frequency domain impedance characteristic is analyzed, and a dynamic grouping result of the doubly-fed wind turbine generator is obtained through a clustering algorithm; adopting a capacity weighting method to obtain parameters of an equivalent wind turbine generator; determining reserved nodes and eliminated nodes of the system according to a dynamic grouping result of the wind turbine generator, and obtaining equivalent parameters of the current collection network by adopting an REI static equivalence method; and establishing a doubly-fed fan series compensation grid-connected system simulation model based on the simulation platform, comparing the steady-state power flow, the dynamic response and the sub / super-synchronous oscillation characteristics before and after equivalence, and analyzing the equivalence precision. The new energy station dynamic equivalence method provided by the invention has good equivalence precision in steady-state power flow and dynamic response characteristics, and provides an accurate model basis for analyzing the stability of a high-proportion new energy power system.

The invention discloses a series compensation platform secondary equipment shielding effect analysis method and system under strong electromagnetic interference, and the method comprises the steps: carrying out the multi-conductor modeling of a series compensation platform and a bus, and carrying out the finite element modeling of the primary equipment of the series compensation platform, thereby building a rapid transient overvoltage simulation model of the primary equipment of the series compensation platform; performing simulation to obtain rapid transient overvoltage between the low-voltage bus and the high-potential platform at the position of the secondary equipment measurement box under the set overvoltage condition; finite element modeling is carried out on the secondary equipment, a rapid transient overvoltage signal between a low-voltage bus and a high-potential platform is applied to the modeling, electric field distribution under the set overvoltage condition is obtained through simulation, and the shielding effectiveness of a measurement box of the secondary equipment under different frequencies is calculated; changing the materials of the secondary equipment to analyze the electromagnetic shielding effectiveness of different materials under the set overvoltage condition; according to the invention, effective anti-electromagnetic interference measures can be provided effectively, and the anti-interference performance of the secondary equipment of the high-voltage series compensation platform is improved.

The application discloses a hybrid distribution transformer power electronic module capacity configuration method for load prediction, and the capacity of a series compensation module is calculated based on a target area load prediction value to represent power processing capacity required for voltage compensation; when the capacity of a parallel compensation module is determined, the capacity value of the series compensation module is reused to realize collaborative assumption of a load fluctuation compensation task, so that the capacity of the parallel compensation module is equal to the sum of the following two parts: a) the product of the capacity of a transformer in a transformer area and a fixed proportionality coefficient, to represent the proportion of reactive power compensation demand; and b) the capacity value of the series compensation module; and the series compensation module and the parallel compensation module with actual power processing capacity not less than the calculated capacity are selected.

The invention discloses an equivalent simulation test method and system for sub-synchronous oscillation and super-synchronous oscillation of a double-frequency coupling type synchronous motor, and the method comprises the steps: constructing an oscillation voltage equivalent model of the double-frequency coupling type synchronous motor, and enabling the model to obtain the oscillation voltage equivalent model of the double-frequency coupling type synchronous motor by modifying the sub-synchronous resonance frequency, the super-synchronous resonance frequency, the line series compensation ratio, the maximum torsional vibration angular displacement value and generator parameters; effective control on oscillation current, voltage and power is realized; according to a motor stator voltage time domain disturbance equation, a sub-synchronous signal test circuit and a super-synchronous signal test circuit are constructed, and electrical quantities during sub-synchronous oscillation and super-synchronous oscillation are simulated; according to the invention, a reliable algorithm and an intuitive circuit model are used to simulate the sub-synchronous and super-synchronous oscillation key electrical quantity of the power system, great convenience is provided for the research and test of broadband oscillation monitoring equipment in the aspect of sub-synchronous and super-synchronous oscillation, and the development of the broadband oscillation monitoring technology of the power system is promoted.

According to the controllable series compensation transformer through-flow automatic compensation circuit and compensation method, a main adjustment capacitor group, a fine adjustment capacitor group, a fine adjustment inductor group, a main adjustment contactor contact, a fine adjustment contactor contact, an anti-parallel thyristor contact, a protection contactor contact, a choke inductor, a voltage transformer 1, a control module and a voltage transformer 2 are connected to obtain input test parameters; and setting capacitance and inductance in the main adjustment capacitor group, the fine adjustment capacitor group and the fine adjustment inductor group, selecting a test mode, calculating the compensation capacitance, and performing capacitor switching based on a capacitor gear switching method according to the calculated compensation capacitance. Capacitance compensation can be accurately carried out on the transformer, the power factor of the power supply in the test process is improved, and the working efficiency of the test power supply is improved.

The invention provides a power distribution network non-power-outage loop-closing power transfer device and a control method. The device comprises a loop-closing power transfer controller, and a direct-current voltage stabilizing circuit, a series compensation circuit and a load switching circuit which are connected in sequence, the direct-current voltage stabilizing circuit serves as direct-current input of the series compensation circuit and is used for providing voltage support; the series compensation circuit is connected in series between the original supply bus and the transfer supply bus during working and is used for compensating the voltage difference between the original supply bus and the transfer supply bus; the load switching circuit is used for controlling the connection and disconnection of the series compensation circuit between the original supply bus and the transfer supply bus; and the closed-loop transfer controller is used for performing signal acquisition on the original supply bus, the transfer bus, the direct-current voltage stabilizing circuit and the series compensation circuit, and controlling the closed-loop transfer device to complete closed-loop transfer between the original supply bus and the transfer bus. The series compensation circuit does not need to bear all loads on an original supply bus, and only needs to be designed according to the power required for generating the compensation voltage, so that the capacity of the required power electronic converter is reduced.

The invention relates to the technical field of wireless power transmission, and particularly discloses a two-constant-voltage power supply wireless charging circuit structure suitable for illumination application, which comprises a transmitting side and a receiving side, the transmitting side comprises a direct current input power supply UD, an inverter circuit, a transmitting side series compensation inductor L1, a transmitting side series compensation capacitor C1, a transmitting side parallel compensation inductor L2, a transmitting side parallel compensation capacitor C2, a transmitting side series compensation capacitor C3 and a transmitting coil LP; and the receiving side comprises a receiving coil LS, a receiving side series compensation capacitor C4, a receiving side parallel compensation capacitor C5, a receiving side parallel compensation inductor L3, a receiving side series compensation inductor L4, a rectifying circuit, a filter capacitor CF and a load RB. The circuit structure has the beneficial effects that the circuit structure effectively solves the problem that constant voltage output of various specifications cannot be realized in a traditional wireless power transmission system, and can meet the requirement that an illumination system needs different illumination intensities in different environments.

The present application relates to the technical field of eddy current pulse thermography detection, and specifically discloses an eddy current pulse thermography detection system based on LCC resonance topology and a control method thereof, aiming at the problems of resonance frequency drift and excitation current fluctuation caused by the change of lift-off height of the traditional eddy current pulse thermography excitation source, the present application adopts LCC resonance topology, sets compensation inductance, parallel compensation capacitor and series compensation capacitor to meet specific parameter conditions, decouples the excitation coil current from the lift-off height and keeps it constant, and at the same time ensures that the system realizes soft switching in the full load range. On this basis, a voltage closed-loop control strategy is further introduced, the real-time lift-off height is calculated, and the output voltage of the full-bridge inverter is adjusted accordingly to realize constant power output and stable temperature rise of the tested piece under the change of lift-off height. The present application effectively overcomes the influence of the change of lift-off height on the consistency of the detection result, and improves the reliability and on-site operation flexibility of the system.