针对中长期电压稳定问题,提出了一种基于分段校正模型的在线电压协调控制策略,采用模型预测控制方法在线滚动求解最优控制策略。预测模型在控制周期初始时刻根据实测信息校正,使其能够跟踪实际系统的运行状态,确保了预测轨迹的可靠性。结合实测信息线性处理预测周期内负荷动态状态变量轨迹,使预测模型中的微分方程转化为非线性代数方程,避免了优化控制过程中动态微分方程的处理。提出了一种针对分段校正模型的电压响应预测方法,将最优电压协调控制模型的求解转化为易于处理的混合整数规划问题。仿真结果表明,该方法能够协调不同地点和类型的控制措施,在确保全局控制效果的基础上大幅减少了计算时间,能够满足在线电压协调控制的要求。
In view of the mid-long term voltage stability, an on-line coordinated voltage control strategy based on the segmented-correction model is proposed. The optimal control strategy is solved onqine with the model predictive control (MPC) method. In order to ensure reliable prediction results, the prediction model is modified every time the control horizon is initiated according to the actual measurement information to track the operating state of the actual system. Dynamic load state variable trajectories are linearly approximated within the prediction horizon by referring to the actual measurement information. The differential equations in the prediction model are transformed into nonlinear algebraic equations to avoid dealing with the dynamic differential equations in the optimization control process. A voltage response predictive method for the segmented- correction model is proposed, which transforms the problem solving of the optimal coordinated voltage control model into a tractable mixed-integer linear programming problem. Simulation results show that the proposed scheme can meet the requirement of on-line coordinated voltage control with its capability of coordinating the control of different types and different geographical locations and greatly reducing the calculation burden and time.