当风电机组并入微电网后,要求风机能够工作在最大功率点跟踪和固定功率点跟踪两种模式,并适时切换。针对这个问题,提出了一种新型的直驱永磁风电机组在微电网下的自适应多模式功率控制策略。该控制策略结合磁场定向控制应用于永磁同步发电机和两电平全功率背靠背变流器构成的发电系统中。该控制策略的控制目的是使风电机组根据不同工况运行在最大功率点跟踪模式或跟踪性能增强型的非最大功率点跟踪模式。新型控制与传统变步长爬山搜索算法相比,速度更快、鲁棒性更强,当环境和功率需求变化时,能迅速切换到非最大功率点跟踪模式,且具有快速的动态响应和精确的稳态响应。最后,基于小功率永磁直驱风电机组试验平台开展了试验研究,对新型控制策略的控制性能进行了试验验证。
While in a microgrid, the wind turbine generator is required to work in both maximum power point tracking and fixed power point tracking modes, and it must change the mode properly. Aiming at this problem, an adaptive multi-mode power control for direct-drive permanent magnet synchronous motor (PMSG) in a microgrid has been proposed. The control strategy combined with field oriented control was applied to a PMSG and two-level full power back-to-back converter drive system. The objective of the control strategy was to make the wind turbine operating in the maximum power point tracking mode or tracking performance enhancement mode of non-maximum power point tracking. Compared to the conventional variable-step hill climbing search algorithm, the novel control was faster, and the robustness was stronger. The novel control has a fast dynamic response to the change of the power command and the environment, and has an accurate steady-state response as well. Finally, based on the low power direct-drive PMSG test platform, some tests have been done to verify the validity of the new proposed method.