摘要
提出1种利用直流侧功率量进行控制的交直流混合微电网双向变换器改进下垂控制策略,该控制策略能在整流、逆变、空闲模式自主平滑切换。改进下垂控制策略满足孤岛和并网2种运行模式,省去了多种控制策略切换。利用直流侧功率量控制避免了归一化运算,减少了由于直流母线电压和交流频率小范围波动引起的电力电子器件频繁动作。仿真结果表明,该控制策略可将直流母线电压和交流频率维持在额定值附近,保证交直流混合微电网稳定运行,提高系统可靠性。
The bidirectional converter in AC/DC hybrid microgrid is an important part for balancing the power between AC and DC, and its control mode is extremely important.Propose an improved droop control strategy for bidirectional converters using DC side power control. The control strategy can autonomously and smoothly switch among rectification, inversion, and idle mode. The improved control strategy is used to satisfy both the islanding and grid-connected modes of operation, eliminating multiple control switching.The DC side power amount control avoids the normalization operation and reduces the frequent operation of the power electronic device due to the small fluctuation of the DC bus voltage and the AC frequency. The simulation results show that the control strategy can maintain the DC bus voltage and AC frequency near the rated value, ensure the stable operation of the AC-DC hybrid microgrid, and improve system reliability.
引文
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