基于逆系统理论的VSC-HVDC新型控制

在讨论电压源型高压直流输电(VSC-HVDC)的控制策略中,根据所给出的拓扑结构,建立三相静止系统下的数学模型;再根据控制需要,通过派克矩阵,将VSC-HVDC转换为dq0旋转坐标下的数学模型;通过逆系统理论,将非线性VSC-HVDC系统强制线性化。同时,为了实现直流输电系统有功和无功的解耦控制,选择直流电流和换流站交流输入输出电流作为反馈来设计相应的控制器,并采用李亚普诺夫间接法证明了所提出的控制策略下VSC-HVDC闭环非线性系统的稳定性。计算机数值仿真显示,大扰动下的系统动态响应特性较好,可实现无功、有功的解耦控制,且具有一定的鲁棒性。

New Control of VSC-HVDC Based on the Inverse System Theory

According to the given topology of voltage source converter based HVDC system (VSC-HVDC), three-phases mathematic model in stationary frame is established. For the control design, it is transformed to a dq0 mode in synchronous frame with the Parker matrix. With the Inverse System theory, non-linear VSC-HVDC mathematic model is forced to be a linear one, at the same time, the DC current and the input & output currents of converter are selected as the feedbacks for the decouple control of active and reactive power, furthermore, Lyapunov indirect method is used to prove the stability for the closed-loop nonlinear system under the proposed control strategy in this paper. The numerical simulations manifest that the VSC-HVDC system has better dynamic characteristics during varying major disturbance, and the decouple control of active and inactive power is realized. Furthermore, this control mode is robusticity.