Abstract: An impact tool includes a first cover mounted at an end of a first housing facing away from an output mechanism, where a first bearing seat is formed on or connected to the inner side surface of the first cover; a display mechanism including a human-computer interaction assembly and a retaining assembly, where the retaining assembly is used for supporting the human-computer interaction assembly, the retaining assembly is disposed on the outer side of the first cover, the human-computer interaction assembly sets and displays an operation parameter, and the operation parameter includes the rotational speed of a motor and an impact time parameter; and a control mechanism driving the motor according to the set operation parameter so that an output shaft outputs the preset tightening torque.

Abstract: An apparatus for injecting impedance into a high voltage (HV) transmission line is disclosed. The apparatus comprises a plurality of modular flexible alternating current transmission systems (FACTS) based impedance injection units (IIUs), each modular FACTS based IIU without fault current protection. The apparatus further comprises a fault current protection module external to the modular FACTS based IIUs. The fault current protection module is coupled to the modular FACTS based IIUs to provide fault current protection to the modular FACTS based IIUs.

Abstract: An apparatus for injecting impedance into a high voltage (HV) transmission line is disclosed. The apparatus comprises a plurality of modular flexible alternating current transmission systems (FACTS) based impedance injection units (IIUs), each modular FACTS based IIU without fault current protection. The apparatus further comprises a fault current protection module external to the modular FACTS based IIUs. The fault current protection module is coupled to the modular FACTS based IIUs to provide fault current protection to the modular FACTS based IIUs.