Abstract: The present disclosure relates to a high-strength concrete and a preparation method thereof. The high-strength concrete includes lignin, recycled fine powder, cement, water, sand, gravels and a water reducing agent. The recycled fine powder is recycled fine powder of discarded concrete, and is prepared by separating solid waste of discarded buildings, then performing impurity removal and crushing processing, and grinding same by a ball mill into dust with a particle size of less than 0.16 mm. The lignin is discarded wood lignin, which is prepared by crushing the wood, stirring and extracting a sodium hydroxide aqueous solution with a mass concentration of 5% for 1 to 2 hours at the temperature of 80 DEG C. to obtain a black lignin alkali solution, adding a hydrochloric acid solution with a mass concentration of 30% into the alkali solution for stirring, and making the pH reduced to 7.0 for standing and layering.

Abstract: Disclosed is a device for monitoring icing of a transmission line and preventing a tower from falling down, including a power transmission tower, an insulator string and a connecting mechanism; the connecting mechanism includes two connecting plates, and a monitoring-control connector and a damping component are arranged between the two connecting plates; sides of the two connecting plates are respectively provided with connecting grooves matched with two ends of the monitoring-control connector; the monitoring-control connector is provided with a monitoring component in signal connection with a master station; the two ends of the monitoring-control connector are respectively provided with load release components and are fixedly connected with the two connecting plates, and sides of the two connecting plates further from the monitoring-control component are fixedly connected with the power transmission tower and one end of the insulator string respectively, the other end of the insulator string is hung with w

Abstract: Disclosed is an infrared thermal image classification and hot spot positioning method of a photovoltaic panel, comprising following steps: constructing a photovoltaic panel infrared thermal image data set, preprocessing the image data set, and dividing into a training set and a testing set according to a preset proportion; training an auxiliary generating countermeasure network based on the training set to obtain a trained generator and a trained discriminator, training an encoder by combining the image data in the training set with the generator, and fixing the parameters of a trained encoder; inputting the image data in the test set into a trained discriminator to obtain a photovoltaic image classification result; inputting images in the test set into the trained encoder, and then inputting the images into the generator for a reconstruction; comparing pixels of the input images with the reconstructed infrared thermal images, and positioning hot spots.

Abstract: A synergic identification method for dynamic stability of a power system is provided, including: acquiring each dominant oscillation mode; acquiring a critical wavelet scale factor range corresponding to each dominant oscillation mode; calculating an oscillation modality of the dominant oscillation mode corresponding to the critical wavelet scale factor range by a right singular vector corresponding to a maximum value among first singular values of each reconstructed wavelet coefficient matrix in the critical wavelet scale factor range; calculating, according to the relation between left and right feature vectors and the estimated oscillation modality, a left feature vector corresponding to each dominant oscillation mode and calculating a participation factor of each measurement channel in this dominant oscillation mode; calculating direction cosines between measurement channels by the oscillation modality of the dominant oscillation mode, and classifying coherent generator groups or coherent bus groups in th

Abstract: The present invention discloses an N-1 static security analysis method for integrated energy system, including the following steps: constructing a static model of the IES including electro-gas-thermal coupling elements, calculating multiple energy flow equations, and calculating the multiple energy flow of the IES to obtain an operating status of the IES; constructing a N-1 preconceived accident set, calculating multiple energy flow of the IES, and performing security verification to the status of the coupling elements in each preconceived accident set, respectively; analyzing the security verification results by comparing the results of static security analysis under different control modes, so that an N-1 static security analysis is achieved. The present invention fully researches the security of the IES, comprehensively considers the influence of the output changes of the coupling elements on the operating point of the energy system, and evaluates the security and stability of the IES.

Abstract: There is provided an optimization model and methods for quick track of a Static Voltage Stability Region (SVSR) boundary of a power system. The methods include using a base power flow as a starting point to track a first power system SNB point by a traditional OPF and mapping the SNB point to obtain an SVSR boundary point, and includes repetitively changing a power stress direction to a new direction and tracking a power system SNB point in the new power stress direction and mapping the power system SNB point to obtain a new SVSR boundary point, and includes returning to the first power system SNB point if the power stress direction angle is ?0; repetitively changing the power stress direction to a new direction and tracking a power system SNB point and mapping the power system SNB point to obtain a new SVSR boundary point.

Abstract: Disclosed is a method for calculating a transient overvoltage at a direct current (DC) sending end by taking into account a dynamic process of a control system. First, a first reactive power consumed by a converter station is calculated based on system operation parameters and a DC closed-loop transfer function. Then, a transient voltage change rate is calculated based on the first reactive power and a second reactive power on an alternating current (AC) side. Finally, the transient voltage change rate is iterated to obtain the transient overvoltage. According to the technical solution provided by the embodiments of the present disclosure, the transient overvoltage is determined based on the system operation parameters and the closed-loop transfer function of a DC line, the dynamic process of control parameter change caused by a control action of the control system after a fault occurs can be determined by the closed-loop transfer function of the DC line, whereby the transient overvoltage can be determined.