XU Xiaoning, ZHOU Xuesong. Control Strategy for Smooth Transfer Between Grid-connected and Island Operation for Micro Grid[J]. 2018, 44(8): 2754-2760.DOI:
微网脱/并网运行模式平滑切换控制策略
摘要
随着分布式发电技术的不断成熟和发展
微网与大电网之间的友好协作变得更加重要。因此在改进下垂控制基础上增加了相位的前馈补偿思想
提出了基于线性逐次逼近相位修正算法的相位调节方法
设计了一种可实现微网从孤岛向并网运行模式切换前的同步并网控制器。通过实验可以看出
在改进后的控制策略下
频率超调量较改进前减少了约38%
频率调节时间减少了30%
并网前的相位误差几乎为0
频率误差也能控制在0.01 Hz以内
从而保证了微网的平滑稳定运行。
Abstract
With the maturity and development of the distributed generation technology
it becomes more and more crucial that micro grid should smoothly cooperate with the power grid. Consequently
by adding phase feed forward compensation on the basis of the advanced droop control
we put forward a new phase regulation method by using the modified algorithm based on linear gradually approaching. A running controller is designed to realize the synchronization before the transferring from the island mode to the grid-connected mode. The results reveal that
under the advanced control strategy
the frequency overshoot is reduced by about 38%
the frequency modified time is reduced by 30%
the error of phases is about zero
and the frequency error can be controlled within 0.01 Hz
which ensure the smooth and stable operation of the microgrid.