Abstract: This invention relates to the technical field of harmonic elimination for ferromagnetic resonance for a voltage transformer (abbreviated as PT), in particular, to a harmonic elimination method for ferromagnetic resonance for an active resistance-matching voltage transformer based on PID-adjustment, including compiling a resistance matching algorithm; designing and building a harmonic elimination control system based on the PID control strategy; presetting an active resistance-matching strategy; designing an engineering scheme for placing resistors.

Abstract: A nail gun having a driving and controlling mechanism. The driving and controlling mechanism comprises a driving assembly disposed inside a casing of the nail gun for striking nails in a striking direction; and a control assembly controlling the driving assembly. The driving assembly comprises a piston movably disposed inside the casing and attached to a striking member for striking the nails; at least one power spring in contact with the piston; a pushing component for pushing the piston towards the power spring; and a motor for rotating the pushing component. The control assembly comprises a main switch configured to produce a first electronic signal; and a safety switch configured to produce a second electronic signal. The main switch and the safety switch are in communication with the motor such that the motor is configured to operate when it receives both the first electronic signal and the second electronic signal.

Abstract: A nail gun having an energy storage mechanism for storing energy used for striking nails out of the nail gun, the energy storage mechanism comprises a guiding rod attached to a fixed plate assembly; a piston disposed on the guiding rod; a striking member mounted on the piston for striking the nails; at least one power spring disposed around an outer periphery of the guiding rod; a guide sleeve moveably disposed around the outer periphery of the guiding rod and between the power spring and the guiding rod; wherein a first end of the power spring abuts against the piston and is configured to be compressed to store energy.

Abstract: This invention relates to the technical field of harmonic elimination for ferromagnetic resonance for a voltage transformer (abbreviated as PT), in particular, to a harmonic elimination method for ferromagnetic resonance for an active resistance-matching voltage transformer based on PID-adjustment, including compiling a resistance matching algorithm; designing and building a harmonic elimination control system based on the PID control strategy; presetting an active resistance-matching strategy; designing an engineering scheme for placing resistors.

Abstract: The present disclosure relates to the technical field of potential transformer (PT) ferromagnetic resonance elimination, in particular to a PT ferromagnetic resonance elimination method implemented by actively inputting resistance through an electronic load, including the following steps: setting up a PT, and determining a mapping relationship; constructing a resonance elimination control system; and designing the electronic load as an active resonance elimination device. The present disclosure overcomes a contradiction between a magnitude of resonance elimination resistance and winding overload in a PT open delta during single-phase-to-earth fault and fault clearance, and effectively avoids the technical problems of difficult distinguishing between single-phase-to-earth fault characteristics and power frequency resonance characteristics and causing resonance in a single-phase-to-earth fault process.