根据固体氧化物燃料电池( SOFC)的电化学特性和微网的运行要求,建立了含SOFC、BOOST变换器、蓄电池(BESS)、双向DC/DC变换器、DC/AC逆变器和滤波器6部分的SOFC发电系统整体模型,提出了适应各种运行状态的控制策略.DC/AC逆变器采用v/f下垂控制,包含内环电流和外环电压；逆变器控制模块中包含重连同步环节,作用于微网从孤岛到并网模式的平滑转换.为了提高SOFC的动态响应速度,在直流母线侧并联储能蓄电池,采用双向DC/DC变换器的滞环充放电控制来提高功率调节速度.构建了包含SOFC发电系统的微网模型,并网、孤岛以及两种模式间切换时的仿真结果表明所提出的SOFC发电系统模型能正确反映SOFC的电化学特性,控制策略效果良好,能在微网各种运行条件下保证微网的稳定运行.%According to the electrochemical character of solid oxide fuel cell (SOFC) and operational requirements of micro grid, the overall model of SOFC power generation system which contains SOFC, BOOST converter, storage battery(BESS), buck-boost converter, DC/AC inverter and filter is developed and the control strategy adapting to various operating status is proposed. DC/AC inverter adopts V/f droop control strategy which includes inner current and outer voltage loops. The controller also incorporates synchronization block for ensuring smooth and safe reconnection from islanding mode to grid-connected mode in micro grid. In order to improve the dynamic response speed of SOFC, storage battery is in parallel with DC bus through buck-boost converter which adopts hysteresis charging/discharging control strategy to raise the power regulation speed. The structure of micro gird which contains SOFC power generation system is set up. The simulation results of SOFC generation system operating on grid-connected mode, islanding mode and switching between two modes verify that the model of SOFC generation system can correctly reflect the electrochemical characters of SOFC. The effect of the control strategy is good and can ensure the stable operation of micro grid in all kinds of operating conditions.
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