A High-Performance Online Uninterruptible Power Supply (UPS) System Based on Multitask Decomposition Qiongbin Lin, Member, IEEE, Fenghuang Cai, Wu Wang, Sixiong Chen, Zhe Zhang, Senior Member, IEEE, Shi You, Member, IEEE

 

A High-Performance Online Uninterruptible Power Supply (UPS) System Based on Multitask Decomposition Qiongbin Lin, Member, IEEE, Fenghuang Cai, Wu Wang, Sixiong Chen, Zhe Zhang, Senior Member, IEEE, Shi You, Member, IEEE

Abstract—High quality online uninterruptible power supplies (UPS) are widely used in applications e.g. precision medical equipment with critical loads. This paper proposes a low-cost and high performance online UPS system. Firstly, the performance improvement of a bidirectional switch based bridgeless power factor (PFC) converter, which is regulated by a hybrid control strategy with load current feedforward is studied. Secondly, the proposed closed-loop controller integrates improved predictive current control with predictive voltage control and applies to the second-stage neutral-point-clamped (NPC) three-level inverter for low output voltage harmonics. Moreover, a push-pull dc-dc converter interfaces and boosts voltage of a 24V battery bank as the backup energy source. Considering complexity of the UPS system as well as cost reduction, we implement a multi-task decomposition method for control on a monolithic low-cost digital signal processor (DSP) embedded with Control Law Accelerator (CLA). Finally, the experimental results from a 1kVA a prototype can effectively verify validly of the theoretical analysis and design.

LINK:https://orbit.dtu.dk/files/190201335/A_High_Performance_Online_Uninterruptible_Power_Supply_UPS_System_Based_on_Multi_task_Decomposition.pdf