基于自适应逻辑开关控制的全功率直驱风机切换故障穿越控制研究

In order to improve the balanced and unbalanced fault ride-through capability of permanent magnetic synchronous generator-based wind turbines (PMSGWTs) and to explore the utmost control potential of power electronics converters during the transient processes of power systems, this proposal will carry out the following three aspects of exploratory investigations. .First, this proposal will try to find a nonlinear control method, which does not require detailed system models, and has superior robustness with respect to the external impulsive disturbances. The nonlinear control method should also be able to explore the utmost control capability of control devices, and we will try to prove the closed-loop stability of a nonlinear system controlled by the proposed control method..Second, this proposal will try to design a fault ride-through controller for PMSGWTs operating under balanced fault conditions based on the proposed control method. The proposed controller should be able to make use of the largest control effort of power electronics converters, and should be asymptotically stable near the equilibrium point. Meanwhile, the d-axis and q-axis control voltages of the proposed controller should work in a coordinated manner..Third, this proposal will design an unbalanced fault ride-through controller for PMSGWTs based on the proposed control method to enhance the negative sequence current control capability of PMSGWTs. Moreover, we will explore the coordination mechanism between the positive and negative sequence control voltages of the proposed controllers..The theoretical work of this proposal will investigate the possibility of combining the observer-based control method and the logic bang-bang control theory. The application work of this proposal will inspire the study on exploring the utmost control potential of power electronics converters during the transient processes of power systems.

为了提升全功率直驱风力发电机（PMSGWT）对平衡和不平衡故障的穿越能力，充分发掘电力电子换流器在电力系统暂态过程中的控制潜能，本项目将首先从控制理论的角度探索一种不依赖于系统精确模型、对外界冲击性扰动具有强鲁棒性且能够发掘控制设备最大控制潜能的控制方法，同时对该控制方法控制下系统的稳定性证明方法进行研究；其次，本项目将在所提控制方法的基础上设计PMSGWT的平衡故障穿越控制器，该控制器应能发挥电力电子换流器的最大控制能量、在平衡点附近渐近收敛、控制器内部dq轴回路控制命令应相互协调；此外本项目将设计基于所提控制方法的PMSGWT不平衡故障穿越控制器，提升PMSGWT对系统不平衡电流的控制能力，同时将探索正负序控制回路控制命令的协调机理。本项目在理论方面的工作将探索模态观测理论与逻辑开关控制理论结合的可能性，在工程应用方面的研究将启发对电力电子换流器在电力系统暂态过程中最大控制潜能的探索。

为了提升全功率直驱风力发电机（PMSGWT）对平衡和不平衡故障的穿越能力，充分发掘电力电子换流器在电力系统暂态过程中的控制潜能，本项目首先从控制理论的角度提出一种不依赖于系统精确模型、对外界冲击性扰动具有强鲁棒性且能够发掘控制设备最大控制潜能的自适应逻辑开关控制方法，该方法结合了模态观测和时间最优控制的优势，避免了逻辑开关控制器求取输出变量高阶导数的缺陷，提升了控制器的自稳能力；同时，对自适应逻辑开关控制器控制下系统的稳定性证明方法进行研究，提出了基于李雅普诺夫稳定定理和前推回代的混杂控制系统闭环稳定性证明方法；其次，基于自适应逻辑开关控制设计了PMSGWT的平衡故障穿越控制器，该控制器应能发挥电力电子换流器的最大控制能量、在平衡点附近渐近收敛、控制器内部dq轴回路控制命令应相互协调；此外，项目设计了基于逻辑开关控制的PMSGWT不平衡故障穿越控制器，提升PMSGWT对系统不平衡电流的抑制能力，并提出了正负序控制回路控制命令的协调策略。本项目在理论方面的工作实现了模态观测理论与逻辑开关控制理论的结合，在工程应用方面的研究实现了对电力电子换流器在电力系统暂态过程中最大控制潜能的探索。