Abstract: A multi-level direct current converter, a voltage control method for a flying capacitor, and a control apparatus are provided. The multi-level direct current converter includes a controller, a flying capacitor, two switching transistor groups, and an inductor. The method for controlling a flying capacitor includes: in response to that an absolute value of a difference between a sampling voltage and a reference voltage of the flying capacitor is greater than a first threshold, adjusting a duty cycle difference between first switching transistors in two switching transistor groups or a phase difference between carriers of first switching transistors in two switching transistor groups based on a magnitude of an inductor current. According to this application, a voltage of the flying capacitor can be controlled, to improve operation stability of the multi-level direct current converter.

Abstract: A rotor blade tip clearance control method and a rotor blade manufactured using same. The control method includes: coinciding, along an axial direction of an aircraft engine, a center of gravity of a rotor blade with a center of gravity of a rotor wheel disk supporting the rotor blade; rotating the rotor wheel disk to measure a leading edge deformation amount of the rotor blade; measuring a trailing edge deformation amount of the rotor blade; comparing the deformation amounts; and adjusting the center of gravity of the rotor wheel disk until the leading edge deformation amount tends to be approximately equal to the trailing edge deformation amount. The method can effectively improve or even solve the problem of inconsistent radial displacements of a leading edge and a trailing edge during the operation.

Abstract: This application describes examples of a photovoltaic energy storage system including an inverter and an energy storage device. In one example, an input end of the inverter is connected to a direct current bus. An output end of the inverter is connected to an alternating current power grid. The energy storage device is connected to the direct current bus. The inverter is configured to send high-voltage ride-through information to the energy storage device when a high-voltage ride-through occurs in the alternating current power grid. The energy storage device is configured to: when the high-voltage ride-through information is received, adjust an output voltage reference value to maintain a discharging working state if the energy storage device is in the discharging working state, or adjust a charging power reference value to maintain a charging working state if the energy storage device is in the charging working state.

Abstract: A rotor blade tip clearance control method and a rotor blade manufactured using same. The control method includes: coinciding, along an axial direction of an aircraft engine, center of gravity of a rotor blade with center of gravity of a rotor wheel disk supporting the rotor blade; rotating the rotor wheel disk to measure a leading edge deformation amount of the rotor blade; measuring a trailing edge deformation amount of the rotor blade; comparing the deformation amounts; and adjusting the center of gravity of the rotor wheel disk until the leading edge deformation amount tends to be approximately equal to the trailing edge deformation amount. The method can effectively improve or even solve the problem of inconsistent radial displacements of a leading edge and a trailing edge during the operation.

Abstract: A blade platform, comprising a pair of side edges and a pair of bottom edges, wherein the side edge comprises a linear portion and a curved portion, wherein the linear portion comprises a first linear portion and a second linear portion, and the curved portion comprises a first curved portion and a second curved portion; wherein the first linear portion and the second linear portion are connected to two ends of the curved portion and are tangent to the curved portion, slopes of the first curved portion and the second curved portion are in the same direction and the first curved portion and the second curved portion are circumscribed. The benefits of the blade platform are that the problems of platforms pushing against each other and get stuck during the working state as in the prior art or lack of accuracy in the test results of the blade circumferential clearance test and the dynamic balance test can be avoided.

Abstract: A fault detection method for a three-phase power distribution system, which includes three phase lines and a neutral line. The three phase lines intersect with the neutral line at a neutral point, the three phase lines include a first phase line, a second phase line, and a third phase line, and at least one of the three phase lines is connected to the neutral line. The method includes: obtaining a voltage between every two phase lines; obtaining a voltage between each phase line and the neutral point based on the voltage between every two phase lines; obtaining a voltage between the neutral line and the neutral point based on a voltage between each phase line and the neutral line and the voltage between each phase line and the neutral point; and detecting the voltage between the neutral line and the neutral point, whether a fault occurs in the neutral line.

Abstract: A fault detection method for a three-phase power distribution system, which includes three phase lines and a neutral line. The three phase lines intersect with the neutral line at a neutral point, the three phase lines include a first phase line, a second phase line, and a third phase line, and at least one of the three phase lines is connected to the neutral line. The method includes: obtaining a voltage between every two phase lines; obtaining a voltage between each phase line and the neutral point based on the voltage between every two phase lines; obtaining a voltage between the neutral line and the neutral point based on a voltage between each phase line and the neutral line and the voltage between each phase line and the neutral point; and detecting the voltage between the neutral line and the neutral point, whether a fault occurs in the neutral line.

Abstract: This application provides a maximum power point tracking method and a device, to improve conversion efficiency of a control device in a photovoltaic power generation system, and reduce a loss of a power generation capacity. The method includes: adjusting, by the control device, an input voltage of the control device, where the input voltage is generated by one or more of the photovoltaic module and is transmitted to the control device; determining whether a difference between a first input power and a second input power of the control device is less than or equal to a setpoint, adjusting the input voltage of the control device according to the first input power and the second input power.

Abstract: This application provides a maximum power point tracking method and a device, to improve conversion efficiency of a control device in a photovoltaic power generation system, and reduce a loss of a power generation capacity. The method includes: adjusting, by the control device, an input voltage of the control device, where the input voltage is generated by one or more of the photovoltaic module and is transmitted to the control device; determining whether a difference between a first input power and a second input power of the control device is less than or equal to a setpoint, adjusting the input voltage of the control device according to the first input power and the second input power.

Abstract: The present invention discloses a live-working robot, comprising: a telescopic arm and a working hopper, wherein the working hopper and the telescopic arm are slidably connected along a vertical direction and the telescopic arm is provided with the drive component for driving the working hopper to reciprocate along a vertical direction. The live-working robot provided in the present invention achieves a movement of the working hopper along the vertical direction by slidably connecting the working hopper and the telescopic arm along the vertical direction and providing the telescopic arm with the drive component for driving the working hopper to reciprocate along the vertical direction.

Abstract: Circuits are disclosed, for example for driving fluorescent lamps, and such circuits may form part of a ballast. First and second sensing circuits can apply respective signals to a control circuit as a function of an end-of-lamp life condition and of the number of re-strike attempts.

Abstract: Circuits are disclosed, for example for driving fluorescent lamps, and such circuits may form part of a ballast. First and second sensing circuits can apply respective signals to a control circuit as a function of an end-of-lamp life condition and of the number of re-strike attempts.