應用於多階換流器之可重組電池陣列電壓平衡方法

Abstract

本論文提出一個應用於多階換流器之可重組電池陣列電壓平衡方法。對於應用在單相多階換流器之電池電源而言，可重組電池陣列之電池組電壓容易會有電壓不平衡的情形發生，其原因在於多階換流器內不同階層的操作會使得電池組消耗不同大小的能量。根據各階層的操作模式，會讓特定的電池組以較長時間輸出能量，而造成其電池組有較大的電壓下降。對較低電壓的電池組來說，如果沒有特別的控制處理，會發生過度放電的情況，而造成電池永久性的損害，減少電池之壽命。為了解決在多階換流器中電池電壓不平衡的問題，本論文提出單電壓偵測平衡方法達到應用於多階換流器之可重組電池陣列電壓平衡。本論文提出之方法可以針對在不同電池初始電壓的情形下達到電壓平衡，而且只需要一個電壓偵測電路即可實現。在本論文中，將會介紹所使用的可重組電池陣列架構與多階換流器之操作原理，接著說明單電壓偵測平衡方法的控制流程，最後以4階層之多階換流器來進行模擬與實作驗證本論文提出之平衡方法。

A voltage balance method for the reconfigurable battery array (RBA) for multilevel inverter (MLI) applications is proposed in this thesis. The RBA can generate different levels of dc voltage for the multilevel inverter application which implies that each battery module inside the RBA will provide different level of energy for the output load. Therefore, the energy consumption as well as the voltage of individual battery cell in the RBA will be different. For battery module with lower voltage level, a permanent damage may occur and its lifetime will be shorten if no action is taken. In this thesis, the single voltage sensing balance (SVSB) method is proposed to equalize the battery modules of the RBA which is adopted for the MLI application. The proposed SVSB method only need one voltage sensor to accomplish the battery module equalization under different initial battery voltages. The circuit structure of the RBA and the operation principle for the MLI application are introduced first in this thesis. Then, the control flow chart of the proposed SVSB method will be illustrated. Finally, the computer simulation and hardware experimental results of a 4-level prototype MLI are given to verify the performance of the proposed SVSB method.