59results about How to "Improve anti-disturbance performance" patented technology

The invention discloses a hub electric automobile direct yawing moment control method with a fault tolerance function. The method mainly includes the steps that a linear two-degree-of-freedom model isestablished, the ideal yaw velocity and the ideal mass center side slip angle of a vehicle are obtained, a state observer is established, and the actual mass center side slip angle of the vehicle isestimated; a seven-degree-of-freedom vehicle dynamic model is established as a control object, a fault factor is introduced, and a vehicle dynamic model with a drive motor fault is established; basedon an adaptive terminal sliding mode theory and a PI control theory, an upper layer controller is designed, and a virtual control command is obtained; and based on fault information and a moment optimal distribution method, a fault tolerance lower layer controller is designed, and the traveling performance and safety performance of the vehicle are guaranteed after the fault occurs. The proposed method guarantees the traveling safety after the fault occurs, under the condition that the executor fault exists or not, the traveling stability of the vehicle can be guaranteed, and the traveling stability range is enlarged. Meanwhile, the control coordination of four wheels is improved, and the response performance of the fault vehicle is improved.

The invention discloses a fractional integral sliding mode-based speed control method for a permanent magnet synchronous motor. The fractional integral sliding mode-based speed control method for the permanent magnet synchronous motor comprises the following steps of constructing a fractional integral sliding mode surface S, and designing a fractional integral sliding mode rotary speed controller for performing rotary speed regulation. The invention also discloses a fractional integral sliding mode-based speed control device for the permanent magnet synchronous motor. According to the fractional integral sliding mode-based speed control method for the permanent magnet synchronous motor disclosed by the invention, high-performance speed following control of the motor can be realized under the condition that parameter perturbation and load disturbance exist in a control system for the permanent magnet synchronous motor, and the defect that an integral saturation effect and the transient performance are reduced due to a big initial error or actuator saturation in traditional integral sliding mode control is overcome.

The invention discloses a non-smooth technique-based direct yaw moment control method of electric vehicles. By means of the method, the vehicle stability under extreme driving circumstances can be increased under the conditions of external disturbances and system uncertainty. The method comprises the following main steps: (1) building a linear two-degree-of-freedom vehicle dynamic model and a seven-degree-of-freedom whole vehicle dynamic model; 2, calculating the ideal yaw velocity and ideal side slip angle of the vehicles through the linear two-degree-of-freedom model, and constructing a state observer to observe the actual side slip angle of the vehicles; 3, designing a non-smooth control module controlled by yaw moment on the basis of non-smooth control technique; and 4, distributing the yaw moment by using a moment distributing module, thereby realizing the stable control of the vehicles. The method disclosed by the invention has the advantages that (1) the system has fast convergence performance and better disturbance-resistant performance; and (2) a chattering phenomenon is effectively avoided while good robust performance is obtained at the same time.

The invention relates to a ship-based net collision recovery unmanned aerial vehicle, comprising an airframe, an airfoil, ailerons, a horizontal tail, an elevating rudder, vertical tails, rudders, an engine and a propeller, wherein the airfoil is mounted on the airframe and adopts an upper single-airfoil layout; the left side and the right side of the airfoil are respectively provided with one aileron; the horizontal tail is mounted at the upper end of the tail part of the airframe and adopts double vertical fin layout; the left and right vertical tails are connected with the wing ends of the horizontal tail respectively; the horizontal tail has a 1.5-degree mounting angle; the front edge of the horizontal tail is higher than the rear edge of the horizontal tail; the elevating rudder is arranged on the rear edge of the horizontal tail; the rudders are arranged on the rear edges of the vertical tails; the engine is mounted at the tail end of the airframe and is used for driving the propeller to rotate. The unmanned aerial vehicle has the characteristics that the endurance time is long, so a flight mission with high requirement on endurance is convenient to carry out during navigation; the wind-resistant ability is strong and the stability is high, so the unmanned aerial vehicle is applicable to the flight emission under a complicated sea condition; catapult-assisted take-off and high-precision net collision zero-distance recovery are adopted, so the unmanned aerial vehicle is applicable to emission and recovery on a narrow space on naval vessels; the whole machine adopts modular design, so containerized transportation is facilitated and the occupied space on the naval vessel is reduced.

The invention relates to an LCL-type grid-connected inverter parallel connection virtual impedance control method. Under weak grid conditions, a parallel connection virtual impedance control method isprovided, difference is solved between grid-connected current ig and grid-connected instruction current parameters iref to obtain a signal ei, then difference is solved between the signal ei and a current signal fed back by an inverter side virtual impedance Zp(s), a and after double-current feedback control, a PWM modulating wave signal is generated to be transmitted into a PWM generator to generate a switch signal. After parallel connection virtual impedance, a system phase margin is increased, a harmonic is obviously lowered, the robustness and the interference resisting capability of thesystem are effectively improved, it is guaranteed that grid-inlet current is not greatly influenced by grid resistance, a parallel connection inverter can still normally work under the change of gridresistance wide ranges, the harmonic is small, and the applicability is good; in the dynamic response process of transforming a half load to a full load of the grid-connected virtual impedance, compared with a traditional method, the transition time is shorter, the overshooting amount is reduced, and stable running of a grid-connected inverter system is not influenced.

The invention discloses a real-time absolute ranging method and system based on single-chamber dual-femtosecond optical comb cross-correlation analysis. The method comprises steps: S1, two simultaneously-outputted femtosecond optical combs with different repetition frequencies are generated, the two different repetition frequencies are fr1 and fr2, and the repetition frequencies are locked to an atomic clock by frequency stabilization control; S2, after the beam of the two femtosecond optical combs passes through an interferometer optical path module, the orthogonal polarization components ofoptical comb pulse return light (reference light and measurement light) and local optical comb pulses are measured, and after combination, two groups of femtosecond laser pulse pairs with mutually-perpendicular polarization directions are generated; S3, two-path optical balance cross-correlation signals for reference and measurement are generated, and the signales can be generated by a femtosecondpulse cross-correlation analysis unit in the embodiment of the invention; and S4, the balance cross-correlation signals are subjected to high-speed digital signal analysis processing to obtain a ranging result. The system is the device used for executing the above method. The method and the system disclosed in the invention have the advantages of large ranging range, fast updating speed, high measuring precision and simple operation and the like.

The invention belongs to the field of controller design, and is used for allowing tracking error of an observer to be converged to an original point within finite time. According to auto-disturbance-rejection controller design, a classic third-order finite extended-state observer serves as an example, and when the classic third-order finite extended-state observer meets the property of finite-time convergence, the parameters of the observer are solved. It should be understood that for other-order finite-time extended-state observers, parameters can be similarly solved with the method. According to the technical scheme, a method of an auto-disturbance-rejection controller based on the finite-time extended-state observer includes the specific steps that 1, the third-order finite-time extended-state observer is built; 2, for the extended-state observer, the parameter of the extended-state observer is solved; 3, disturbance feedback u is designed, wherein u=(u<0>-z<3>) / b, and z<3>=f (y,w,t), and the system is approximated as a second-order integrator series type. The auto-disturbance-rejection controller design is mainly applied to the controller design occasion.

The invention discloses an online measurement device and an online measurement method of double-pressure difference gas-liquid flow rate. The online measurement device comprises a Venturi flowmeter; a gas-liquid pipe is arranged at one end of the Venturi flowmeter; the gas-liquid pipe is connected with a V-cone flowmeter through a connecting flange; a first pressure gauge is arranged at the front end of the Venturi flowmeter; a second pressure gauge is arranged at the throat part of the Venturi flowmeter; a fourth pressure gauge is arranged at the rear end of the V-cone flowmeter; a third pressure gauge is arranged at a position, between the fourth pressure gauge and the connecting flange, on the V-cone flowmeter. During an actual online gas-liquid flow rate measurement process, respective pressure differences of the Venturi flowmeter and the V-cone flowmeter in a pipeline are acquired and are transmitted into a processor; a gas-liquid two-phase flow rate measurement model is established in the processor; respective flow rates of a gas phase and a liquid phase are calculated and outputted according to the measured pressure differences and by combining the physical parameters of the pipeline and a fluid inputted through a human-computer interface; the online measurement device and the online measurement method have high measurement stabilities.

The invention discloses an electric bicycle control method based on an integral sliding mode and a disturbance observer. The method comprises two parts, namely, design of integral sliding mode control and design of disturbance observer control. The integral sliding mode control comprises design of a sliding mode surface and design of a sliding mode control law so as to guarantee the closed-loop stability performance of a system; the disturbance observer is used for observing the external disturbance and the parameter vibration of the system and introduced into a closed-loop system as a feed-forward item. A designed composite controller can realize high-performance speed tracking control on a motor under the condition that the electric bicycle control system has bonded parameter variation and load disturbance. Through simulation comparisons, the composite controller can effectively reducing buffeting of sliding mode control output and has good dynamic and static characteristics and robustness.

The invention discloses a motor mechanical parameter identification method and system based on a high-order sliding-mode observer. The method comprises the following steps of operating a motor under two working conditions of the same acceleration and different rotating speeds, obtaining output signals of the high-order sliding-mode observer, and then calculating a friction coefficient estimation value; eliminating the influence of a friction coefficient error, obtaining output signals of the high-order sliding-mode observer when the motor is operated in two working conditions of different acceleration, and then calculating a torque inertia estimation value; and eliminating the influences of the friction coefficient error and a torque inertia error, obtaining an output signal of the high-order sliding-mode observer when the motor is operated in a working condition, and calculating a load torque estimation value. According to the method, the mechanical parameter identification is realized, the accuracy of a mechanical parameter identification result is improved, and the application value of the mechanical parameter identification is improved.

The invention discloses a hybrid modeling method for a feeding system of a numerical control machine tool. The hybrid modeling method comprises a dynamic basic model and a neural network deviation model based on big data, wherein the dynamics basic model is obtained through dynamics theory analysis and parameter identification; the neural network deviation model is obtained by analyzing and training an instruction sequence, simulation prediction data of the dynamic basic model and actual response data; and the instruction sequence is input into a system mixing model, and the actual response sequence is predicted to obtain a mixed prediction sequence. Compared with a pure dynamic model, the technical scheme of the invention has the advantages that the simulation of a highly nonlinear process (such as a reverse process) is more accurate, and compared with a pure neural network model, the generalization ability under different processing technologies is stronger. Through a hybrid modelingmode, accurate simulation of a complex dynamic feeding system is realized.

The invention discloses a droop-PQ type micro-grid inverter power supply with hysteretic characteristics. The droop-PQ type micro-grid inverter power supply comprises distributed primary energy, a detection module, a control module, a driver module and an inverter convertor bridge. The detection module comprises a sampling unit and an input signal processing unit; the control module is used for generating control signals acting on the driver module in the mode that information of active power and reactive power, sent by the detection module, of a system is compared with a power limit value preset for the power supply; a control method of the control module involves droop-PQ control, and the control module has four threshold values; the driver module comprises a PWM generating circuit and a drive amplifying circuit; the inverter convertor bridge is used for connection and electric energy conversion between the distributed primary energy and a micro-grid. The droop-PQ type micro-grid inverter power supply enlarges the power regulation range, provides stable voltage and frequency and enables the system to operate reliably and stably and to have good anti-disturbance performance.

The invention relates to an anti-disturbance time-frequency domain wave-front detection method, belongs to the field of optical measurement. The method comprises the following steps of: first, acquiring a sequence of interference patterns, and after subtracting a mean value of the sequence from a light intensity sequence of pixels at any same position in each interference pattern, performing fast Fourier transform and performing broadband filtering frequency shift; then, performing the fast Fourier transform on an obtained frequency spectrum sequence; next, solving a logarithm of a result, and obtaining a phase statistical sequence of a time sequence after extracting and unwrapping an imaginary part of the result; later on, performing linear fitting on the obtained phase statistical sequence, and storing the first value of the sequence obtained after fitting in a matrix, and taking the first value as a computation value of an initial phase of a pixel; and finally, repeating the operations, after storing all computation values of the initial phases of other pixels in the matrix, and reestablishing the distribution of wave-front initial phase through airspace unwrapping. The method of the invention is simple and convenient, easy to implement, and free from the influence of environmental vibration, and has a very good anti-disturbance effect.

The embodiment of the invention discloses a permanent magnet synchronous motor control device and method based on a variable-order fractional-order sliding mold, and relates to the technical field of alternating current servo motor control. The problem of performance reduction in a fixed-order fractional-order sliding mold control method can be solved, and the following precision is improved. According to the permanent magnet synchronous motor control device and method based on the variable-order fractional-order sliding mold, a fuzzy variable-order controller and a variable-order fractional-order sliding mold surface are constructed, and a variable-order fractional-order sliding mold rotary speed controller is designed to conduct rotary speed regulation. The permanent magnet synchronous motor control device and method based on the variable-order fractional-order sliding mold are suitable for operational control of a permanent magnet synchronous motor.

The invention discloses an ecological wetland device which is characterized by comprising a protection system (1), a purification system (2) and a control system (3), wherein the purification system (2) and the control system (3) are arranged in the protection system (1); the protection system (1) comprises an outer basin (11); an inner basin (12) is arranged in the outer basin (11); a plurality of holes (18) are formed at the bottom of the inner basin (12); a support shaft (13) is vertically arranged in the center of the inner basin (12); and a support platform (14) for accommodating the control system (3) is arranged in the middle of the support shaft (13). The ecological wetland device disclosed by the invention is simple in structure and convenient to assemble and detach, and can conveniently move to other polluted areas for purification in the next stage; and the effect of purifying water movably can be achieved with low manual moving expense.

The invention provides a permanent magnet synchronous motor speed loop control parameter setting method based on a fractional order sliding mode controller, and mainly relates to the technical field of alternating current motor control. The permanent magnet synchronous motor speed loop control parameter setting method based on the fractional order sliding mode controller comprises the steps of constructing a fractional order sliding mode control surface and optimizing and setting the parameters of the fractional order sliding mode controller through an intelligent algorithm. The invention further designs a permanent magnet synchronous motor speed control device based on fractional order sliding mode control. According to the permanent magnet synchronous motor speed control method and device based on the fractional order sliding mode controller, the high-performance control over the motor can be achieved under the condition that load disturbance exists in the control system of the permanent magnet synchronous motor. According to the method, the fractional order sliding mode controller is used for replacing a traditional integer order sliding mode controller, and the improved particle swarm optimization algorithm is adopted for automatically optimizing and setting the parameters of the fractional order controller, so that the good anti-disturbance capacity, robustness and highercontrol precision are realized.

The invention discloses a finite time control method for a vehicle-mounted photoelectric tracking platform based on a disturbance observer. According to the method, a disturbance observer and a finitetime controller are organically combined, complement each other and are used for controlling a photoelectric tracking platform. On the basis of a mathematical model of the photoelectric tracking platform, the disturbance observer is designed to observe disturbance borne by the photoelectric tracking platform, and the disturbance is used as a feed-forward quantity for compensation. Then, a given signal is compared with an actual signal to obtain a first-order error model containing an equivalent disturbance term, and a feedback control rate is designed by using a finite time control method onthe basis of the first-order error model. Through mathematical analysis, the relationship between the boundary of the steady-state error of a closed-loop system and the parameters of the controller under the condition of equivalent interference is given. The composite control method enables the photoelectric tracking platform to have better anti-disturbance performance and more excellent convergence performance.

The invention discloses a frequency control method based on wind power consumption, comprising the steps as follows: A, calculating a wind power deviation of each sub-area in the control area; B, calculating a total wind power deviation of all sub-areas in the control area; C, distributing the total wind power deviation to each sub-area of the control area to adjust the regional control deviation,and calculating the adjusted regional control deviation after dynamic adjustment of each sub-area; and D, issuing a control command to the generator set in the sub-areas by the automatic power generation control system corresponding to the sub-areas according to the adjusted regional control deviation to realize the frequency modulation control. The invention is capable of sharing the frequency modulation responsibility equally among the sub-areas of the control area to further improve the current state of the frequency regulation of the power grid, so as to achieve the maximum complementaryfrequency modulation capability between the sub-areas, thereby ensuring safe and stable operation of the grid while improving the wind power consumption capacity of the grid.

According to the method, a microgrid island multi-inverter parallel system under the influence of sensor faults is researched, and a nonlinear multi-inverter parallel system TS fuzzy model is established. A fuzzy proportional-integral observer is designed to effectively estimate the fault; meanwhile, a fuzzy special observer is adopted, and faults are detected and isolated through a residual reconstruction mechanism. And then, through established fuzzy Taylor series expansion and Lyapunov, sufficient conditions for verifying the stability of the system are proved, and the stability is proved.And finally, simulation is carried out in a Simulink environment, and the effectiveness of the fault diagnosis method is verified. The fault diagnosis method based on the island multi-inverter parallel sensor is reasonable in design, stable control under parameter uncertainty faults and actuator faults can be well achieved, good tracking performance and fault tolerance are shown, a new thought isprovided for design of a fault diagnosis system of the multi-inverter parallel sensor in an island mode, and the fault diagnosis method is suitable for large-scale popularization and application. Goodengineering application prospects are realized.

The invention discloses a photovoltaic plate rotation positioning control method based on a linear active disturbance rejection controller. A photovoltaic plate rotation positioning control system isadopted for controlling a photovoltaic plate rotation positioning system, and the photovoltaic plate rotation positioning control system mainly comprises a linear active disturbance rejection controller, a sensing detection mechanism, a drive circuit and a DC motor and realizes photovoltaic plate rotation positioning. The designed linear active disturbance rejection controller comprises three parts: the first part is a linear tracking differentiator (LTD), the second part is a linear extension state observer (LESO), and the third part is a control law. The active disturbance rejection controller (ADRC) absorbs results of modern control theory, and adopts a core concept of PID error feedback control; the most prominent feature is that all uncertain factor roles on a controlled target are accredited to total disturbance, realizing feedback linearization of a dynamic system. The designed linear active disturbance rejection controller of a corresponding order has good tracking performanceand disturbance rejection performance.

Although the problem that a gain parameter is difficult to control is solved by each improved PID, the calculation quantity is increased; and moreover, inherent conflict between rapidness and overshoot exists in a traditional PID and each improved PID, the traditional PID and each improved PID both have inherent defect of disturbance rejection capability shortage, and thus, limitation exists in practical application. By a quasi-PI disturbance perception control method of a three-phase permanent-magnet synchronous motor, the conflict between the rapidness and the overshoot is effectively solved, moreover, the quasi-PI disturbance perception control method also has the characteristics of high control accuracy, good robust stability, high disturbance rejection capability and the like, and thegain parameter is completely determined by integral step; and particularly, the gain parameter is not needed to be controlled again when an external environment is abruptly changed, and a control strategy of a typical control theory and a modern control theory is completely overturned. And the quasi-PI disturbance perception control method has important theoretical significance and application value to rotational speed control of the three-phase permanent magnet synchronous motor (PMSM).

The invention provides a motor used for a compressor. The motor comprises a stator and a rotor, wherein the stator comprises a stator iron core which adopts an annular cylinder shape; the ratio k of the inner diameter to the outer diameter of the stator iron core is greater than 0.5; the rotor is arranged in a columnar space defined by the stator iron core; the rotor comprises a rotor iron core and a magnetic part; the magnetic part is arranged on the rotor iron core; the displacement V of the compressor, the quality M of the rotor iron core and the magnetic part, and the maximum outer diameter R of the outer edge of the rotor satisfy that V / (M*R<2>)*1000 is greater than 2 and less than 4, wherein the unit of the displacement V of the compressor is cm<3>; the unit of the quality M of the rotor iron core and the magnetic part is g; and the unit of the maximum outer diameter R of the outer edge of the rotor is cm. By virtue of the motor provided by the invention, the miniaturization of the motor can be ensured, rotary speed fluctuation is reduced, the operational stability of the compressor in low-frequency operation process is improved effectively, the complete machine energy efficiency of the compressor is improved, and the noise of the compressor is lowered.

The invention discloses a V / f-PQ type micro-grid inverter power supply with hysteretic characteristics. The V / f-PQ type micro-grid inverter power supply comprises a signal input module, a V / f-PQ hysteretic control module, a double-feedback decoupling PWM (pulse width modulation) control module, an output driving module and a VSC main circuit, wherein the signal input module respectively outputs received first voltage signals and current signals, the V / f-PQ hysteretic control module outputs frequency signals or active power signals and reactive power signals or second voltage signals to the double-feedback decoupling PWM control module after processing the received first voltage signals and the first current signals, the double-feedback decoupling PWM control module outputs a PWM control pulse to the output driving module, the output driving module outputs driving signals to the VSC main circuit, and when the VSC main circuit receives the driving signals, the externally input direct current is converted into alternating current to be output. The V / f-PQ type micro-grid inverter power supply has the advantages that different threshold values and loop width are set for different power supplies, the false triggering possibly caused on a controller by normal fluctuation of a system can be effectively avoided, and the power supply is prevented from fluctuating and repeatedly changing in the range of a certain value.

The invention discloses a high-reliability electric-drive motor control method. According to the control method, a fuzzy PR regulator is adopted to replace a traditional speed PI controller during speed regulation, so that the self-adaptability and the anti-disturbance capacity of a system are improved, and the tracking effect is very good; a perdition controller is adopted to replace a traditional current PI controller during current regulation, so that the hysteresis characteristic of the traditional current PI controller is avoided, and the bandwidth and the dynamic property of the system are improved; finally, the reliability of the system is improved with the control method that SVM and a four-leg inverter are combined, so that the system can still run normally in case of a failure. The control method has the characteristics of quick dynamic response capability, high self-adaptability, high anti-disturbance capacity, good tracking effect, high reliability and the like and is applicable to motor drive occasions with higher requirements for the dynamic property and the reliability.

The invention discloses a commercial power outage detection method, electronic equipment, a storage medium and an energy storage system, wherein the method comprises the following steps of acquiring afirst sampling value and a second sampling value of a commercial power voltage, wherein the second sampling value is a voltage sampling value at the next moment after the first sampling value; carrying out phase locking calculation on a difference value obtained by subtracting the first sampling value from the second sampling value; calculating a commercial power voltage amplitude value accordingto the result of the phase locking calculation; and judging whether commercial power outage occurs or not according to the commercial power voltage amplitude value. The difference value of the two sampling values before and after the commercial power voltage is multiplied with the phase locking signal, and a commercial power voltage amplitude value is calculated according to the result of phase locking calculation; next, whether commercial power outage occurs or not is judged according to the calculated commercial power voltage amplitude value; and therefore, the complexity is relatively low,the judgment real-time performance is high, the anti-disturbance performance is relatively high, and the accuracy is high.

The invention discloses a sliding mode active disturbance rejection control method and system based on a simulated annealing particle swarm algorithm. The method comprises the following steps of establishing a speed ring second-order active disturbance rejection model of a permanent magnet linear synchronous motor; combining the double-power reaching law and the rapid reaching law to obtain an improved rapid double-power reaching law; and obtaining a second-order speed loop improved sliding mode active disturbance rejection controller based on the improved fast double-power reaching law and active disturbance rejection control. Based on a simulated annealing particle swarm algorithm, parameters of the second-order speed loop improved sliding mode active disturbance rejection controller areoptimized, and technical problems that buffeting exists in PMLSM sliding mode control in the prior art, the number of parameters of active disturbance rejection control is large, adjustment is difficult, and the external disturbance resistance is poor are solved; the active disturbance rejection controller is advantaged in that the controller maintains the characteristics of an original active disturbance rejection controller, the number of to-be-adjusted parameters is reduced, smooth transition can be achieved during switching, and meanwhile good recovery performance and disturbance rejection capacity are achieved.

The invention discloses an autonomous underwater vehicle with a rotor. The autonomous underwater vehicle comprises a main body. A rotating shaft perpendicular to a horizontal plane is mounted at the top end of the head of the main body. A vertical rudder is rotatably connected to the rotating shaft, and horizontal fixed fins are symmetrically mounted at the left and right sides of the head of the main body. A thruster is connected to the front end of the head of the main body. The autonomous underwater vehicle further comprises the rotor which comprises a mast mounted in the gravity center position of the overall autonomous underwater vehicle, two supporting legs of the mast are in left-right symmetry with respect to the longitudinal axis of the main body of the autonomous underwater vehicle, and the mast is fixedly connected with a welding part fixed to the main body through bolts. The mast is rotatably connected with a posture control lever through a rotary shaft, a rotor support is rotatably connected to the posture control lever through a rotary central shaft, and a forwarding rotor piece and a backing rotor piece are symmetrically mounted on the rotor support. The negative buoyancy and the loading capacity of the autonomous underwater vehicle are high.

The invention discloses a protection device of a fiber grating detector, which relates to the technical field of optical fiber sensing and comprises a main body structure and sealing structures arranged at two ends of the main body structure. The main body structure comprises an outer sleeve and a transition pad, one end of the transition pad is connected with the fiber outlet end of the fiber grating detector, the other end of the transition pad is in pressing fit with the sealing structure at the upper end of the main body structure, the outer sleeve sleeves the fiber grating detector and the transition pad, and the sealing structure at the lower end of the main body structure is connected with the bottom end of the fiber grating detector; a light inlet optical fiber of the fiber grating detector sequentially penetrates through the fiber outlet end, the transition pad and the sealing structure at the upper end of the main body structure and then is led out of the protection device; a light-emitting fiber of the fiber grating detector passes through the fiber-out end, passes through a gap channel between the fiber grating detector and the outer sleeve, passes through the sealing structure at the lower end of the main body structure and then is led out of the protection device. While underground sealing protection is provided for the detector, vibration detection of the detector is not affected.

The invention discloses a control method for a DC-DC conversion unit in a non-contact power supply system. The method comprises: combining a feedforward control link and an error feedback link in a current control link of each DC-DC converter; in the feedforward control link, performing feedforward PI control on the actual output current and the expected current in the DC-DC converter to obtain afeedforward output quantity; and the error feedback link performing feedback PI control on the difference between the actual output current and the expected current and zero, and generating a compensation signal to correct the feedforward output quantity. The invention further discloses a control system which comprises a feedforward control link and an error feedback link. The feedforward controllink is used for performing feedforward PI control on the actual output current and the expected current in the DC-DC converter to obtain a feedforward output quantity. The error feedback link is usedfor performing feedback PI control on the difference between the actual output current and the expected current of the DC-DC converter and zero, and generating a compensation signal to correct the feedforward output quantity. The method and the system have the advantages of stable and reliable output and the like.