단상 반도체 변압기의 출력 전력 전향 보상을 통한 과도 응답 개선 = A Transient Response Improvement by Output Power Feedforward Compensation for Single-Phase Solid-State Transformer--Bang Jaehyeon Department of Electrical Engineering Graduate School of Konkuk University-

 

ABSTRACT 

A Transient Response Improvement by Output Power Feedforward Compensation for Single- Phase Solid-State Transformer Bang Jaehyeon

Department of Electrical Engineering Graduate School of Konkuk University 

This paper proposes a output power feedforward compensation method for Dual Active Bridge(DAB) converter based 2-stage single-phase solid-state transformer. Solid-State Transformer(SST) is a bidirectional power converter which is capable of electrical isolation between input and output stage. SST enables the connection of DC power sources such as PV panels, Fuel Cells, and ESS much easier compared with conventional transformers by forming DC bus. Each stage of SST composes of AC-DC converter and isolated DCDC converter. Especially, DAB converter, which has advantages of galvanic isolation with high frequency(HF) transformer, facility of bidirectional operation, and ease of realizing soft switching, is regarded as one of the most fundamental elements in SST. In contrast to conventional PWM converters, DAB converter controls output power by adjusting the phase shift between output voltage of two H-bridges. 70 For designing output voltage feedback controller, small signal model of DAB converter derived from output power equation with phase reference DAB d is applied. Also, bandwidth limitation caused by 120Hz power ripple in DC-link voltage controller, which induces unequal input and output voltage ratio compared with turns ratio of HF transformer, is described. For eliminating this voltage decoupling with current peak rising of leakage inductor, output power-based feedforward compensation method for DC-link voltage controller is proposed. Furthermore, the effectiveness of feedforward term is identified by confirming the reduction in output impedance of converter based on small signal model. In comparison of experimental results, proposed method verified the improvement in transient DC-link voltage decrease by 24.8% and leakage inductor current peak increase by 27.7% during load step input. It also yielded improvement in DC-link voltage increase by 23% while unload transient. Keyword : Solid-State Transformer(SST), Dual Active Bridge(DAB) converter

ORIGINAL LINK: http://www.riss.kr/search/detail/DetailView.do?p_mat_type=be54d9b8bc7cdb09&control_no=491adc48c7a349efffe0bdc3ef48d419&keyword=sst%20solid%20state%20transformer

ALTERNATIVE LINK: 

https://www.mediafire.com/file/6nohyto2co5zglz/A+Transient+Response+Improvement+by+Output+Power+Feedforward+Compensation+for+Single-Phase+Solid-State+Transformer.pdf/file