Study On Multiple Ring Tuned Mass Damping For High-rise Porcelain Cylindrical Electrical Equipment

As the economy grows, the power supply system has been booming consistently.High-Rise Porcelain Cylindrical Electrical Equipment (HRPCEE) plays an importantrole in the system and is essential to the safe operation of power system. Earthquakedamage investigation shows that HRPCEE is vulnerable because of its function featuresand material characters. It is urgent to develop damping techniques which might notonly obviously reduce the seismic inner-force response but also control thedisplacement response of the HRPCEE structures.This paper aims on developing a kind of shock absorption technique usingMultiple Ring Tuned Mass Damper (MRTMD). Two kind of typical HRPCEEstructures are chosen and ANSYS simulations are carried out in order to discuss thepossible influence on HRPCEE caused by MRTMD. Relevant practical installationadvices are given.The main contents of the paper are as follows:(1) Seismic methods of HRPCEE and the history of RTMD are introduced.(2) A rigorous theory of tuned mass dampers for SDOF systems subjected toharmonic force excitation and harmonic ground motion is discussed. Variouscases, including an undamped TMD attached to an undamped SDOF system, adamped TMD attached to an undamped SDOF system, and a damped TMDattached to a damped SDOF system, are considered. This provides a theoreticalbasis for the later study.(3) For the first type of electrical equipment，optimal installation location ofRTMD, optimal damping ratio of RTMD are discussed. The effects of RTMDfrequency offset, MRTMD damping control and MRTMD damping controllingfor higher modes are also discussed. The result shows that the effect ofMRTMD damping control is obviously better than that of SRTMD. The controlof higher modes is feasible.(4) For the second type of electrical equipment, acceleration, displacement andstress response among structure without RTMD, structure with SRTMD,structure with MRTMD controlling for higher modes are compared. The resultshows that MRTMD system controlling for higher modes is effective andirreplaceable.