Pendulum Kinetic Energy Absorption by Active Internal Electromagnetic Damper

Abstract

本論文研製之主動式電磁阻尼利用調變電流的方式，改變系統本身之阻尼係數進而達成抑震和吸收動能的效果。由於風力或震動會導致建築或是機械結構震動，一般會裝上質量阻尼系統使主系統的自然頻率共振振福減少，但由於傳統的阻尼器之阻尼係數已在系統製造完就已經決定，無法進行調控更有效的抑制震動，而震動動能大多轉成油壓阻尼器內的熱能，無法有效地被人類進一步利用。 本論文提出的可主動式電磁阻尼的特點在於利用永久磁石與線圈實現電磁阻尼器，並且可以主動利用電路開關與設計控制器調變阻尼係數，相較於傳統的阻尼系統能夠較迅速的抑制震動，並且不需要對系統供給大量的剎車能量，甚至能將震動動能轉換成電能，另外，此論文提出的抑震演算法也可用於能量獲取裝置，提高裝置的功率輸出。本論文的研究內容包含提出一個主動式電磁阻尼系統模型、動態模擬在擺錘上應用主動式阻尼後的響應，以及在磁路領域上分析並和設計電磁阻尼器、公式化電磁阻尼係數，設計利用調變阻尼係數的抑震演算法，並且建立一個實驗模型以及實驗驗證抑震演算法。

An active internal electromagnetic damper is introduced in this thesis, which is able to decrease the vibration by tuning the current in electromagnetic damper. Since wind, earthquake or other natural factors lead to the vibration of mechanical structures, tuned mass dampers are usually mounted on the vibrated structure to reduce the amplitude at the natural frequency. However, the damping coefficient cannot be changed for passive dampers, which limits the efficiency of energy absorption. Also, the kinetic energy is mostly transformed into the heat energy which is usually hard to be harvested as an energy source. The main feature of the proposed system is to realize the damper by using a set of permanent magnet and coil. The damping coefficient is changed by switching the current in the coil. The active internal electromagnetic damper decreases the vibration more effectively without any external breaking force and further transforms the kinetic energy into electrical energy. In addition, the introduced algorithm can be also applied on energy harvesters to increase the power output of the harvesters. The contents of this thesis include analysis and simulation of the active internal electromagnetic damper in both dynamical and magnetic domain, designing the algorithm of anti-vibration, building an experimental prototype and finally the experimental verification.