输入串联输出并联型(input-series output-parallel,ISOP)直流变换器广泛应用于能源互联网中的直流电网场景,其关键问题在于解决系统模块间输入电压不均衡.为此,结合谐振型和移相型双有源桥(dual active bridge,DAB)变换器,提出一种具备自适应均压能力的混合型模块化ISOP型直流变换器,系统同时具备谐振型DAB的高效率和移相型DAB的灵活控制能力.通过在DAB源端的滞后桥臂中点增设无源的LC谐振支路,该谐振支路与相邻子模块的2个半桥模块共同构成非隔离型双有源半桥,以此来实现系统输入电压的自适应均衡.此外,提出一种低电压穿越(low voltage ride-through,LVRT)方法,在DAB前端连接电压调整模块,模块内部的高频变压器的副边串联电感,当系统输入输出侧发生电压跌落时具备故障穿越的能力,提高系统的暂态可控性.最后,在MATLAB/SIMULINK环境下搭建模型进行验证,可以证明系统的自适应均压性能及故障穿越方法的有效性.
An adaptive-voltage-sharing hybrid DC-DC converter with low voltage ride-through capability
Input-series-output-parallel (ISOP) DC converters are widely used in DC grid scenarios for energy interconnection. The key challenge lies in addressing the input voltage imbalance among system modules. To address this issue, a hybrid modular ISOP DC converter with adaptive voltage balancing capability is proposed, combining resonant-type dual active bridge (SR-DAB) converters and phase-shifting dual active bridge (PS-DAB) converters. This system combines the high efficiency of SR-DAB and the flexible control capabilities of PS-DAB. By adding a passive LC resonant branch at the midpoint of the lagging arm of DAB, this resonant branch and the two half-bridge modules of adjacent sub-modules together form a non-isolated dual active half-bridge, thereby achieving adaptive voltage balancing for the system input. Additionally, a low voltage ride-through (LVRT) method is presented, which involves connecting a voltage adjustment module to the front end of DAB. The secondary side of the high-frequency transformer inside VAM is connected in series with an inductor, providing fault ride-through capability during voltage dips on the input and output sides of the system, thereby improving the transient controllability of the system. Finally, a model is built and validated in the MATLAB/SIMULINK environment, demonstrating the effectiveness of the adaptive voltage balancing performance and fault ride-through method.
input-series output-parallel converterdual active bridgevoltage dropadaptive voltage sharinglow voltage ride-through
万方数据
维普
