Based on the principle of Statistical Energy Analysis (SEA) for non-conservatively coupled systems under general excitations, relationship between noise radiated from and excitations on coupled complex structures is s...Based on the principle of Statistical Energy Analysis (SEA) for non-conservatively coupled systems under general excitations, relationship between noise radiated from and excitations on coupled complex structures is studied, which lays a foundation for the determination of noise/vibration energy by evaluation of exciting forces, and from that the quantitative analysis of the effects of an excitation on sound power from a sub-structure can be done. With extending of the relationship to the study of cutting noise, regression analysis method for evaluating the effects of cutting process on machine tool noise is established. Results show that cutting process has generally negligible effects on machine tool noise, and there is no apparent difference between machine tool noise in cutting condition and in idle one.展开更多
With more and more wind power generation integrated into power grids to replace the conventional turbine-generator (T-G) units,how the subsynchronous resonance (SSR) of conventional T-G units is affected becomes an im...With more and more wind power generation integrated into power grids to replace the conventional turbine-generator (T-G) units,how the subsynchronous resonance (SSR) of conventional T-G units is affected becomes an important technical issue.In this paper,a group of T-G units are interconnected with a series compensated transmission line,and some units are substituted by a nearby DFIG-based wind farm (WF).Under such circumstances,the SSR of power systems would change accordingly.This paper establishes the mathematical model to analyze the torsional interaction (TI) and the induction generator effect of the T-G units.Both eigenvalue analysis and time domain simulations demonstrate the impact of DFIG-based WF on SSR of power systems and how the control parameters of wind farms can affect the SSR.展开更多
文摘Based on the principle of Statistical Energy Analysis (SEA) for non-conservatively coupled systems under general excitations, relationship between noise radiated from and excitations on coupled complex structures is studied, which lays a foundation for the determination of noise/vibration energy by evaluation of exciting forces, and from that the quantitative analysis of the effects of an excitation on sound power from a sub-structure can be done. With extending of the relationship to the study of cutting noise, regression analysis method for evaluating the effects of cutting process on machine tool noise is established. Results show that cutting process has generally negligible effects on machine tool noise, and there is no apparent difference between machine tool noise in cutting condition and in idle one.
文摘With more and more wind power generation integrated into power grids to replace the conventional turbine-generator (T-G) units,how the subsynchronous resonance (SSR) of conventional T-G units is affected becomes an important technical issue.In this paper,a group of T-G units are interconnected with a series compensated transmission line,and some units are substituted by a nearby DFIG-based wind farm (WF).Under such circumstances,the SSR of power systems would change accordingly.This paper establishes the mathematical model to analyze the torsional interaction (TI) and the induction generator effect of the T-G units.Both eigenvalue analysis and time domain simulations demonstrate the impact of DFIG-based WF on SSR of power systems and how the control parameters of wind farms can affect the SSR.
