Abstract: The present invention discloses an in-situ monitoring method and apparatus for a power electronic device explosion. A power electronic device is excited to produce an explosion failure by using a fault excitation module. An electrical signal of the power electronic device is monitored in real time by using an electrical signal monitoring module. Gas information of a test cavity is monitored in real time by using a gas monitoring module. External pictures of the power electronic device are captured by using a high-speed image capturing module. Internal pictures of the power electronic device are captured by using a high-speed X-ray imaging module. Each module in the apparatus is triggered to work according to a predetermined time sequence and time interval by using a time sequence control module. The entire apparatus is controlled and data is acquired, stored, and displayed by using a main control module.

Abstract: A pneumatic automatic pressure regulating valve for automatic driving of a commercial vehicle includes an upper valve body and a lower valve body that form a chamber of the automatic pressure regulating valve. A quick-acting intake valve assembly and a quick-acting exhaust valve assembly are mounted on the upper valve body. A main valve core assembly is mounted on the lower valve body. The quick-acting intake valve and the quick-acting exhaust valve are normally closed and both are configured to regulate an air pressure in the control chamber A such that air enters the working chamber B to increase a pressure or is vented therefrom to reduce the pressure, thereby controlling a pressure in a brake chamber. The pneumatic automatic pressure regulating valve can be widely applied to autonomous vehicles or unmanned driving. The familiarity dependency of a driver on a valve control system is reduced.

Abstract: An automatic pressure regulating valve for multiple levels of driving automation of a commercial vehicle includes an upper valve body, a lower valve body, a piston, a main valve core assembly, a switching valve, a quick-acting intake valve, and a quick-acting exhaust valve. The switching valve, the quick-acting intake valve and the quick-acting exhaust valve are all mounted at an upper end of the upper valve body. The piston is located in a chamber formed by the upper valve body and the lower valve body to divide the chamber into an upper control chamber and a lower chamber. The main valve core assembly is mounted in the lower valve body. The automatic pressure regulating valve is applicable to a commercial vehicle allowing for multiple levels of driving automation.

Abstract: An automatic pressure regulating valve for an electro-pneumatic braking system of a commercial vehicle comprises an upper valve body and a lower valve body. The upper valve body includes a normally open switching valve, a quick-acting intake valve, a normally open quick-acting intake valve, a quick-acting exhaust valve, and a control chamber A. A lower valve body includes a relay valve and a working chamber B. The normally open switching valve has a manually controlled air inlet a and an electronically controlled air inlet b, and an air outlet c connected to an air inlet d of the normally open quick-acting intake valve. An air outlet e of the normally open quick-acting intake valve, an air inlet f of the quick-acting exhaust valve and an air outlet i of the quick-acting air intake valve are connected together to the control chamber A.

Abstract: A power electronic circuit fault diagnosis method based on Extremely randomized trees (ET) and Stack Sparse auto-encoder (SSAE) algorithm includes the following. First, collect the fault signal and extract fault features. Then, reduce the dimensionality of fault features by calculating the importance value of all features using ET algorithm. A proportion of the features to be eliminated is determined, and a new feature set is obtained according the value of importance. Further extraction of fault features is carried by using SSAE algorithm, and hidden layer features of the last sparse auto-encoder are obtained as fault features after dimensionality reduction. Finally, the fault samples in a training set and a test set are input to the classifier for training to obtain a trained classifier. And mode identification, wherein the fault of the power electronic circuit is identified and located by the training classifier.

Abstract: A fault diagnosis method for power electronic circuits based on optimizing a deep belief network, including steps. (1) Use RT-LAB hardware-in-the-loop simulator to set up fault experiments and collect DC-link output voltage signals in different fault types. (2) Use empirical mode decomposition to extract the intrinsic function components of the output voltage signal and its envelope spectrum and calculate various statistical features to construct the original fault feature data set. (3) Based on the feature selection method of extreme learning machine, remove the redundancy and interference features, as fault sensitive feature data set. (4) Divide the fault sensitive feature set into training samples and test samples, and primitively determine the structure of the deep belief network. (5) Use the crow search algorithm to optimize the deep belief network. (6) Obtain the fault diagnosis result.

Abstract: A method for estimating the junction temperature on-line on an insulated gate bipolar transistor (IGBT) power module, including the following steps. Estimate the junction temperature by the temperature sensitive electrical parameter method, set the space thermal model of the extended state, and apply the Kalman filter to the junction temperature estimation. The temperature sensitive electrical parameter method estimates the junction temperature of the IGBT power module in real time, selects the IGBT conduction voltage drop VCE(ON) as the temperature sensitive electrical parameter, and provides a VCE(ON) on-line measuring circuit. The power loss of the diode and IGBT and the estimated value of junction temperature obtained by the temperature sensitive electrical parameter method are taken as the input of the Kalman filter, and measurement noise and process noise are considered to obtain an optimal estimated value of junction temperature.

Abstract: The disclosure discloses a multi-time-scale reliability evaluation method of a wind power IGBT considering fatigue damage and a system thereof. Lifetime information of a power device is comprehensively extracted by using multiple time scales. An electro-thermal coupling model of an IGBT module is established to obtain a junction temperature data. A steady-state junction temperature database of the IGBT in different aging states is established. Based on a SCADA monitoring data, the junction temperature data is outputted in real-time through the electro-thermal coupling model and a real-time thermal stress cycle number is calculated in a short-term time-scale profile, and a wind speed probability distribution curve is obtained in a long-term time-scale profile. A maximum thermal stress cycle number that the IGBT can withstand in different aging stages is obtained in advance and a cumulative damage degree and an estimated lifetime of the IGBT of the wind power converter are calculated.

Abstract: A method and device for calculating a river surface flow velocity are provided based on a variational principle, which are used to capture and process the images of an objective area, and to obtain the flow velocity field data of the objective area with high precision in a non-contact manner. The method and device include 3 steps: (1) preparation before initial flow measurement; (2) capturing a video of the river by an image acquisition device, converting a motion of a pixel flow field of the fluid in a captured image sequence into solving an energy functional optimization problem, and solving partial differential equations to obtain data of pixel flow field distribution; and (3) obtaining space coordinates of the pixel point in a world coordinate system and calculating the flow velocity according to the data obtained in the step 2 and the transformation relationship determined in the step 1.

Abstract: The present disclosure provides a lignite char supported nano-cobalt composite catalyst and a preparation method thereof. In the method, lignite is used as a raw material, and a lignite char supported high dispersion nano-cobalt composite catalyst is obtained by a modified impregnation method followed by a high temperature pyrolysis process. The composite catalyst prepared by the present disclosure has a hierarchical pore structure, a high specific surface area, and uniformly dispersing nano-sized cobalts on the lignite char with controllable particle size, so that the obtained catalyst has an excellent catalytic activity for low-temperature CO2 methanation; moreover, the preparation process is simple and feasible, the raw materials used are cheap and easily available. Therefore, the composite catalyst is very suitable for industrial production and application.

Abstract: The present disclosure relates to a method for growing and doping a strained diamond based on a chemical vapor deposition (CVD) method. The method comprises: depositing a gradient buffer layer and a relaxation layer on a substrate layer in sequence by the CVD method; and finally, depositing a CVD strained diamond layer on the relaxation layer and performing doping by the CVD method. According to the method, a lattice constant of the relaxation layer prepared by utilizing the CVD method is greater than a lattice constant of the diamond, so that a diamond generates a stretching strain. In growing and doping processes, the CVD strained diamond is in a stretching strain state. Therefore, a formation energy of a doped element is low, and it is easy to dope the diamond, so that a doping concentration of the diamond is high.

Abstract: A method and a system for power equipment diagnosis based on windowed feature and Hilbert visualization are provided, which belong to the field of power equipment fault diagnosis. The method includes: obtaining an original data set of monitoring data containing power equipment fault features; introducing windowed feature calculation considering logarithmic constraints to process data to obtain a feature sequence; using Hilbert visualization method for further processing to obtain a Hilbert image data set used to train and verify a convolutional neural network; and finally directly inputting newly obtained test sample data after windowed feature calculation and Hilbert visualization processing into the trained network for fault diagnosis and location.

Abstract: An interferometric demodulation system for a large capacity fiber grating sensing network is provided by the present disclosure, comprising: a continuous light output end of the nanoscale wide-spectrum light source is connected to an input end of the pulse optical modulator, an output end of the reference grating is connected to an input end of the grating array sensing network, and a third communication end of the optical circulator is connected to an input end of the optical amplifier, an output end of the optical amplifier is connected to an input end of the Mach-Zehnder interferometer, three-channel signal output ends of the Mach-Zehnder interferometer are respectively connected to signal input ends corresponding to the embedded signal processor through the photoelectric converter, and the embedded signal processor controls the heating device to control a temperature of an any one of interference arms of the Mach-Zehnder interferometer.

Abstract: A thermoplastic polymer-based composite material and a preparation method thereof are provided. The thermoplastic polymer-based composite material is obtained by impregnating a reinforcing material with a mixture or oligomer of an epoxy resin, a bismaleimide resin, and a bifunctional amine (calculated based on active hydrogen), and then performing an in-situ polymerization. The thermoplastic polymer-based composite material has excellent impregnation effect, excellent secondary processing performance, relatively high heat resistance, excellent flame retardancy, and mechanical properties, and excellent comprehensive performance.

Abstract: A method for dividing communication services in smart substation into different priorities, the method including: determining the priority of a message to be sent according to the service type and its priority definition; the communication services includes trip message, state change message, sampled value message, device status message, time synchronization message, and file transfer message; the corresponding priority is respectively defined as 7, 6, 5, 4, 3, 1; and filling the user priority field of IEEE802.1Q label in a message header with a binary value corresponding to its priority.

Abstract: A device for targeted repair of micro-nano damage of an inner ring of an aeroengine bearing by an electric-magnetic composite field includes a driving device, an ultrasonic shot peening device, a pulsed current generator and a magnet yoke-coil device. The driving device includes a motor and a rotating shaft. The motor drives the rotating shaft to drive a bearing inner ring to synchronously rotate. The ultrasonic shot peening device includes an ultrasonic shot peening cavity, an ultrasonic probe and steel balls, the ultrasonic probe extends into the cavity from an opening in a lower end of the cavity, and the steel balls are placed on the ultrasonic probe. An opening in an upper end of the cavity is placed below the bearing inner ring. The pulsed current generator generates pulsed current on the bearing inner ring. The magnet yoke-coil device can excite a magnetic field around the bearing inner ring.

Abstract: A lidar-based convergence deformation monitoring system for surrounding rock around a TBM shield region, including a data acquisition module. The data acquisition module includes: a lidar, a push-rod motor, an H-bridge circuit, a power supply module, an ARM chip, a guide rod, a linear bearing, a tempered glass cover and a protective case. The lidar and the push-rod motor are connected to a lidar connector to acquire raw data of the surrounding rock and store the raw data in the ARM chip. A middle portion of a top plate of the protective case allows the lidar to extend out of the protective case. The protective case is fastened to an inner wall of the TBM shield through two mounting brackets on both sides of the protective case, and the inner wall facilitates the lidar to extend out of the protective case to perform a measurement.

Abstract: A highly dispersed silicon-carbon solid sol, a preparation method and application thereof. In the high-dispersion silicon-carbon solid sol, the silicon is a dispersed substance, the carbon is a dispersion medium. The silicon is covered by a continuous carbon layer or buried in a continuous carbon phase; a size of the silicon is less than 80 nm at least in one of dimensions, and a mass percentage of the silicon in the highly dispersed silicon-carbon solid sol is 5% to 90%. The nano-silicon particles are covered by the continuous carbon phase, which is not only conducive to obtaining nano-silicon particles with very small sizes, but also can effectively prevent the late oxidation of nano-silicon.

Abstract: A method and system for predicting an insulated gate bipolar transistor (IGBT) lifetime based on compound failure mode coupling are provided. First, a simultaneous failure probability model of a bonding wire and a solder layer is calculated. Next, expectancy of the simultaneous failure probability model is calculated and recorded as a lifetime under a coupling effect. A coupling function relation is established. A lifetime of the solder layer and a lifetime of the bonding wire are predicted. An IGBT lifetime prediction model not taking the coupling effect into account is established. An IGBT lifetime prediction model taking the coupling effect into account is established. In the disclosure, the lifetime of the IGBT module under the coupling effect of the solder layer and the bonding wire may be accurately predicted.

Abstract: The invention discloses a method and a system for characterizing IGBT module aging based on Miner theory, including first establishing a life prediction model with a junction temperature fluctuation Tjm and an average junction temperature ?Tj as inputs; then measuring a chip junction temperature data of an IGBT module; recording the junction temperature fluctuation Tjm and the average junction temperature ?Tj of each power cycle; performing one life prediction in each cycle; and taking a reciprocal of a predicted life corresponding to each cycle and adding them to obtain an aging characteristic parameter D of the IGBT module. The invention may more suitably characterize the aging degree of the IGBT, and has the advantages of monotonically increasing change trend and high resolution.