66results about How to "Reduce power outage time" patented technology

The invention discloses an automatic passage method through phase splitting for an AC-DC-AC electric locomotive which comprises the following steps: before the electric locomotive runs into a neutral section, a traction control system controls a traction motor to work in a regenerative braking mode and controls an inverter to stabilize intermediate DC voltage; a pulse rectifier works in an inversion state; an alternating voltage equal to a traction voltage is generated on the primary side of a traction transformer, thereby making the primary side of the traction transformer obtain zero current from a power supply arm; after the electric locomotive runs into the neutral section, the intermediate DC voltage still maintains stability; the AC phase generated by the inversion of the pulse rectifier in the inversion mode changes gradually so as to make the voltage of the primary side of the traction transformer change to become equal to the traction voltage of a next power supply arm; and then the electric locomotive enters the next power supply arm and runs normally. The method enables the automatic passage through phase splitting; in addition during the phase splitting, a main circuitbreaker does not need to be turned on and off without arc discharge, interception overvoltage and closing surge overcurrent, and an auxiliary system is not deenergized; and the passage through phase splitting has short time, low traction loss and small speed drop.

The invention provides a rainproof distribution box and belongs to the technical field of power distribution equipment. The rainproof distribution box comprises a square box body and plug-in boards, wherein the box body is fixed with static contacts and chutes of a plurality of electrical connectors, the plug-in boards are provided with movable contacts of the electrical connectors, both sides ofeach plug-in board are covered with guide strips, the chutes are adapted to the guide strips and fixed on the inner side wall of the box body, the plug-in boards comprise an upper plug-in board, a middle plug-in board and a lower plug-in board, the upper end surfaces of each plug-in board are fixed with two lifting handles, the outer ends of the plug-in boards are provided with pushing handles, aventilation partition is further horizontally arranged in the box body, the ventilation partition is located below the lower plug-in board, a plurality of ventilation holes are opened in the middle ofthe ventilation partition, the center of the ventilation partition is vertically disposed with a lifting rod, a supporting block is connected to the upper end of the lifting rod, a floating board isconnected to the lower end of the lifting rod, and the floating board completely blocks the ventilation holes after the lifting rod rises. The rainproof distribution box not only keeps the distribution box and the outside world with good ventilation, but also has good waterproofness and high safety.

A printing apparatus includes a printing unit for performing printing by pressing a thermal head onto heat sensitive paper to heat the heat sensitive paper. A battery supplies a voltage to the thermal head, and a battery voltage detecting unit detects the voltage. A printing control unit changes, according to the detected voltage, a power-off time in which power supply from the battery to the thermal head is stopped. The printing control unit calculates the power-off time based on the detected voltage and the resistance of the thermal head and shortens the power-off time as the detected voltage becomes lower thereby shortening the overall printing time without shortening the life of the heating resistance elements of the thermal head.

The invention discloses an active arc extinguishing method, which is used for arc extinguishing of a mechanical switch; a second power supply branch connected in parallel with the first power supply branch is provided for the load outside the first power supply branch composed of a power supply and a mechanical switch. power supply branch, and control the second power supply branch during the opening process of the mechanical switch: first, so that the current I in the first power supply branch at time t n =I n_ref In order to control the target, control the second power supply branch to inject current into the first power supply branch, t is the physical opening time or a certain time after that, the target current I n_ref The direction of the voltage of the power supply at time t is opposite to that of the power supply; then, the output voltage of the second power supply branch is controlled with the voltage phase at both ends of the load tracking the voltage phase at both ends of the load under the condition of power supply as the control target, and the output voltage of the second power supply branch is controlled for at least the duration time for one cycle of the power supply. The invention also discloses an active arc extinguishing device, a circuit breaker and an automatic transfer switch. The invention can realize the effect of rapid arc extinguishing.