Abstract: Provided is a dynamic time warping (DTW)-based real-time diagnosis method for a commutation failure (CF). The method includes: designing a time series template S0 containing a change of a firing angle of a phase-controlled rectifier, and having a length n and a Euclidean distance L; using an n*n matrix M to represent a Euclidean distance between each point in the S0 and each point in the Si, and constricting the matrix M with an Itakura window; calculating values of the matrix M in the search range H; setting different weights for data at different locations, and searching a shortest path L* from point (x1, y1) to point (xn, yn) of the matrix; and setting a range of the distance L of the S0 as ?, determining that the CF fault occurs if the L* is greater than ?L, or otherwise, determining that a system works normally.

Abstract: A dynamic measurement method for spatial magnetic field of transmission lines based on two-dimensional electromagnetic sensor matrix is provided. Data measured by an electromagnetic sensor matrix parallel to the transmission lines is used to calibrate an unmanned aerial vehicle (UAV) flight status, while magnetic field distribution characteristics within a profile of the transmission lines are measured using an electromagnetic sensor matrix perpendicular to the transmission lines, thereby achieving dynamic measurement of the spatial magnetic field of the transmission lines during UAV flight. The method achieves measurement of the magnetic field distribution characteristics within the vertical profile of the transmission lines while ensuring that the UAV flies parallel to the transmission lines.

Abstract: An adaptive IGBT active drive circuit is divided into two parts: a gate drive circuit, and a feedback circuit. The gate drive circuit includes a totem pole unit, and multi-level resistance switching is achieved by using a totem pole parallel structure. The feedback circuit includes a comparison unit, and a logic unit. The comparison unit includes divided resistors, sampling resistors, and a comparator. Internal currents, after passing through the sampling resistor, are compared with current comparison thresholds of complementary transistors to output a digital signal to participate in control of the totem pole. The logic unit is responsible for logically combining a PWM signal and a signal output by the comparison unit to obtain a driving signal of the totem pole.

Abstract: Disclosed is a synchronous and dynamic loading method in electro-magneto-thermo-mechanical multi-field coupling conditions. The method comprises the following steps: applying maximum pulse current to a test object by a pulse power supply to realize loading in extreme electric field and magnetic field conditions; meanwhile, generating a large amount of friction heat by the high-speed rotation of a rotating body and the friction of the test object to realize loading in an extreme-temperature field combined with a large amount of Joule heat and arc heat; synchronously applying pressure to the rotating body by a pressure device to realize loading of extreme force combined with the gravity of the rotating body and the friction force between the rotating body and the test object.

Abstract: Disclosed is an electro-magneto-thermo-mechanical dynamic and synchronous loading device based on a wedge-shaped rotating body. The device comprises a carrier, a wedge-shaped rotating body and a pulse power supply, wherein the wedge-shaped rotating body is positioned above the carrier, the pulse power supply is connected to the carrier and the wedge-shaped rotating body through conductors, a test object is fixed on the carrier, the top of the wedge-shaped rotating body is connected to the output end of a driving shaft through a transmission shaft, the driving shaft drives the wedge-shaped rotating body to rotate and can apply downward pressure, and the wedge-shaped rotating body can be pressed against the test object and rotate on the surface of the test object.

Abstract: Disclosed is an electro-magneto-thermo-mechanical dynamic and synchronous loading device based on a wedge-shaped rotating body. The device comprises a carrier, a wedge-shaped rotating body and a pulse power supply, wherein the wedge-shaped rotating body is positioned above the carrier, the pulse power supply is connected to the carrier and the wedge-shaped rotating body through conductors, a test object is fixed on the carrier, the top of the wedge-shaped rotating body is connected to the output end of a driving shaft through a transmission shaft, the driving shaft drives the wedge-shaped rotating body to rotate and can apply downward pressure, and the wedge-shaped rotating body can be pressed against the test object and rotate on the surface of the test object.

Abstract: Disclosed is a synchronous and dynamic loading method in electro-magneto-thermo-mechanical multi-field coupling conditions. The method comprises the following steps: applying maximum pulse current to a test object by a pulse power supply to realize loading in extreme electric field and magnetic field conditions; meanwhile, generating a large amount of friction heat by the high-speed rotation of a rotating body and the friction of the test object to realize loading in an extreme-temperature field combined with a large amount of Joule heat and arc heat; synchronously applying pressure to the rotating body by a pressure device to realize loading of extreme force combined with the gravity of the rotating body and the friction force between the rotating body and the test object.

Abstract: A method for calculating a maximum output current of multiple thyristor converters connected in parallel, step 1: setting an operating time t; step 2: assuming a trigger angle; step 3: calculating a maximum output current of a single converter according to an output current model for the single converter; step 4: equally dividing a total output DC current into a plurality of parts according to a working duration of six converter bridge arms, thereby obtaining a pulse operating current of a single bridge arm; step 5: checking whether a present junction temperature of a thyristor is below a limiting temperature based on a thermal resistance model for the thyristor, if no, correcting the trigger angle, and repeating step 2 to step 5 until the condition is met; step 6: giving a present trigger angle; and step 7: giving a maximum output current of multiple converters connected in parallel.

Abstract: A method for calculating a maximum output current of multiple thyristor converters connected in parallel, step 1: setting an operating time t; step 2: assuming a trigger angle; step 3: calculating a maximum output current of a single converter according to an output current model for the single converter; step 4: equally dividing a total output DC current into a plurality of parts according to a working duration of six converter bridge arms, thereby obtaining a pulse operating current of a single bridge arm; step 5: checking whether a present junction temperature of a thyristor is below a limiting temperature based on a thermal resistance model for the thyristor, if no, correcting the trigger angle, and repeating step 2 to step 5 until the condition is met; step 6: giving a present trigger angle; and step 7: giving a maximum output current of multiple converters connected in parallel.