A Nonlinear-Disturbance-Observer-Based DC-Bus Voltage Control for a Hybrid AC/DC Microgrid

作者：Wang Chengshan^*; Li Xialin; Guo Li; Li Yun Wei

来源：IEEE Transactions on Power Electronics, 2014, 29(11): 6162-6177.

DOI：10.1109/TPEL.2013.2297376

• DC-AC bidirectional converter
• dc-bus voltage control
• hybrid ac/dc microgrid
• nonlinear disturbance observer (NDO)
• plug-and-play

DC-bus voltage control is an important task in the operation of a dc or a hybrid ac/dc microgrid system. To improve the dc-bus voltage control dynamics, traditional approaches attempt to measure and feedforward the load or source power in the dc-bus control scheme. However, in a microgrid system with distributed dc sources and loads, the traditional feedforward-based methods need remote measurement with communications. In this paper, a nonlinear disturbance observer (NDO) based dc-bus voltage control is proposed, which does not need the remote measurement and enables the important "plug-and-play" feature. Based on this observer, a novel dc-bus voltage control scheme is developed to suppress the transient fluctuations of dc-bus voltage and improve the power quality in such a microgrid system. Details on the design of the observer, the dc-bus controller and the pulsewidth-modulation (PWM) dead-time compensation are provided in this paper. The effects of possible dc-bus capacitance variation are also considered. The performance of the proposed control strategy has been successfully verified in a 30 kVA hybrid microgrid including ac/dc buses, battery energy storage system, and photovoltaic (PV) power generation system.

• 出版日期2014-11
• 单位天津大学