Study On The Theory Of Partial Active Vibration Control Of Power Machinery System

Concentrating on PAC (Partial Active Control) of vibration ofpower machinery system, this paper studied the vibration ofturbogenerator shaft system (TSS) and structural vibration of aninternal combustion engine. After a sound theoretical and characteristicanalysis, strategy of active control of PMC (Partial Mode Control),PCC(Partial Coordinate Control) and PFC (Partial Frequency Control)were introduced according to the character of controlling object. First, we judged the strong and weak of mode response from thecalculated dynamic response of the distributed elastic step spindle ofTSS. The succeeding theoretical analysis and simulation of PMC weremade based on the theory of independent modal-space control. Somecharacters of PMC were also discussed (i.e. coupled control problem,selecting weighting matrix and stability regulation etc.). Sometechnology measures and important references to these procedures wereintroduced in the mean time. Because vibrations of some key parts must be constrained in acertain extent, these vibration responses were set as performancecriteria. By minimizing these performance criteria, the PCC optimalcontrol policy was finally realized. From the simulation of PCC ofvibration of TSS, a good entire control effect including both executivecontrol and non-control subsystems was obtained. Based on the theoretical research, a PMC simulation test is carriedout on a 200MW TSS. The satisfied experimental outcome proved thevalidity of PMC theory. In the case of four supporting brackets symmetry to the cent ofmass, the major structural vibration energy of an engine centralizes onthe coupled vibration in the x and ( z ? β ) degree of freedom. The PMCpolicy is valid too. To exert the effective control energy on the most needful parts, thePFC policy was adopted based on the analysis of characters of PAC infrequency domain. The performance criteria are functions of frequencyusing PFC in linear quadratic control problems. In this case, we canapply supplementary weighting in given frequency band. Based on theanalysis of the vibration of structural vibration of engine in frequencydomain, a simulated calculation of PFC achieved better optimal resultsthan which applying constant weighting.