基于改进支路暂态能量函数的风电并网暂态最优切机控制

大规模风电接入比例的增加对电力系统暂态稳定性造成了影响,因此在风电并网系统的紧急控制中必须考虑风电切机措施。首先分析了双馈式感应发电机(DFIG)的暂态运行特性;然后运用改进支路暂态能量函数法分析了DFIG和传统火力发电机切机效果的差异性。结果表明在风电并网系统的紧急控制中应考虑风电和火电机组切机比例的配合。因此,提出一种考虑风力发电机的最优切机决策模型和一种实用化解法,合理选择最优的风火电切机比例,改善系统恢复过程的特性,极大地提高了系统运行稳定性。通过某区域风电外送系统暂态切机算例验证了该方法高效可行。

Transient optimal tripping control of grid-connected wind farms based on advanced branch transient energy function

Increasing penetration of wind farms will make an impact on the stability of power system transient process. It has resulted in the need for the wind tripping measures in the power system emergency control. Firstly, the doubly-fed induction generator (DFIG) transient operating characteristics are analyzed. Secondly, the different tripping effects between DFIG and conventional synchronous generator are analyzed by using advanced branch transient energy function. The results show that the combination of the wind power and thermal power tripping should be considered in the emergency control of the grid-connected wind farms system. Therefore, an optimal tripping decision-making model considering wind turbine and a practical method are proposed to select the optimal ratio of the thermal to wind tripping reasonably, improve the characteristics of the system recovery process, and enhance the stability of the power system. A transient tripping example of a certain regional system shows that the practical method is feasible and efficient.