Abstract: Provided is a two-stage self-organizing optimized aggregation method and system for distributed resources of a virtual power plant.

Abstract: A method and a system for locating a fault of a complex power line are provided. Several monitoring points on the complex power line can be obtained by providing several traveling wave head monitoring sensors on the complex power line. The complex power line is transformed into coordinates in conjunction with an arrival moment and a location corresponding to the monitoring points, thereby establishing a trunk line fault-locating equation related to a line location, the arrival moment, and a traveling wave propagation speed, from which a first fault point can thus be derived simply and quickly. If a fault point is located on a branch line, a branch line fault-locating equation is then established to derive a second fault point. Furthermore, the first fault point and the second fault point serve as a basis for deriving a target fault point of the complex power line.

Abstract: The present invention discloses a safe operation method for voltage reduction arc suppression of a ground fault phase of a non-effective ground system, for use in ground fault safety operation of a neutral point non-effective ground generator or distribution network. When a single-phase ground fault occurs, an external voltage source is applied at a non-effective ground system side between a bus and the ground, or between a line and the ground, or between a neutral point and the ground, or between a shunting tap of a non-effective ground system side winding of a transformer and the ground, to reduce the fault phase voltage to be lower than the continuous burning voltage of a ground arc, thereby meeting the requirements of long-term non-stop safe operation. The operation means and control method effectively prevent power outages, and improve the reliability and security of power supply.

Abstract: A hydraulic end die of a tunnel secondary lining trolley, comprises a trolley side die-end die assembly (6) and a trolley top die-end die assembly (10). The trolley side die-end die assembly is fixed at an outer ring of a trolley side die assembly (2) by means of a trolley side die-end die fixing device (3); the trolley top die-end die assembly is fixed at an outer ring of a trolley top die assembly (11) by means of a trolley top die-end die fixing device (8); and the trolley side die-end die assembly and the trolley top die-end die assembly are connected to a hydraulic control system by means of a trolley side die-end die hydraulic telescopic device (4) and a trolley top die-end die hydraulic telescopic device (9) respectively. Further disclosed is a construction method for a hydraulic end die of a tunnel secondary lining trolley.

Abstract: A method for preparing tulathromycin, and two intermediate compounds shown in formula V and formula VI are provided.

Abstract: The present invention discloses a safe operation method for voltage reduction arc suppression of a ground fault phase of a non-effective ground system, for use in ground fault safety operation of a neutral point non-effective ground generator or distribution network. When a single-phase ground fault occurs, an external voltage source is applied at a non-effective ground system side between a bus and the ground, or between a line and the ground, or between a neutral point and the ground, or between a shunting tap of a non-effective ground system side winding of a transformer and the ground, to reduce the fault phase voltage to be lower than the continuous burning voltage of a ground arc, thereby meeting the requirements of long-term non-stop safe operation. The operation means and control method effectively prevent power outages, and improve the reliability and security of power supply.

Abstract: A hydraulic end die of a tunnel secondary lining trolley, comprises a trolley side die-end die assembly (6) and a trolley top die-end die assembly (10). The trolley side die-end die assembly is fixed at an outer ring of a trolley side die assembly (2) by means of a trolley side die-end die fixing device (3); the trolley top die-end die assembly is fixed at an outer ring of a trolley top die assembly (11) by means of a trolley top die-end die fixing device (8); and the trolley side die-end die assembly and the trolley top die-end die assembly are connected to a hydraulic control system by means of a trolley side die-end die hydraulic telescopic device (4) and a trolley top die-end die hydraulic telescopic device (9) respectively. Further disclosed is a construction method for a hydraulic end die of a tunnel secondary lining trolley.

Abstract: The proposed invention discloses a safe processing method for active voltage reduction of a ground fault phase of a non-effective ground system, for use in safe processing of a ground fault of a neutral point non-effective ground generator or distribution network. Non-effective ground system side windings of a transformer are equipped with a plurality of shunting taps. When a single-phase ground fault occurs, the shunting tap of the fault phase winding is selected to be short-circuited to ground directly or through an impedance to reduce the fault phase voltage to ensure that the fault point voltage is less than the continuous burning voltage of a ground arc to meet a long-term non-stop safe operation requirements. The proposed method can eliminate the instantaneous single-phase ground fault, suppress the permanent single-phase ground fault current, and limit the rising amplitude of non-fault phase voltage and the risk of non-fault phase insulation breakdown.

Abstract: A method for preparing tulathromycin, and two intermediate compounds shown in formula V and formula VI are provided.

Abstract: The proposed invention discloses a safe processing method for active voltage reduction of a ground fault phase of a non-effective ground system, for use in safe processing of a ground fault of a neutral point non-effective ground generator or distribution network. Non-effective ground system side windings of a transformer are equipped with a plurality of shunting taps. When a single-phase ground fault occurs, the shunting tap of the fault phase winding is selected to be short-circuited to ground directly or through an impedance to reduce the fault phase voltage to ensure that the fault point voltage is less than the continuous burning voltage of a ground arc to meet a long-term non-stop safe operation requirements. The proposed method can eliminate the instantaneous single-phase ground fault, suppress the permanent single-phase ground fault current, and limit the rising amplitude of non-fault phase voltage and the risk of non-fault phase insulation breakdown.