中文摘要：

特高压直流输电系统运行方式灵活多样,直流系统发生故障后功率波动的特性与直流系统的运行方式及故障类型有关。基于几组特高压直流输电系统闭锁实测数据,分析故障下直流系统功率的波动特性并给出了其外特性模型。特高压直流系统单极闭锁有2种基本的冲击模型,即阶跃、脉冲冲击模型;功率波动较为复杂的单极闭锁故障。其外特性模型可由阶跃和脉冲过程叠加构成。针对目前仿真软件中直流故障模型较为单一,难以模拟直流系统故障时复杂的功率变化过程,提出了功率注入外特性模型数据的仿真方法,分析直流故障对交流电网的影响,并在实际系统算例应用,将仿真结果与实测数据进行对比验证了方法及模型的有效性。

英文摘要：

UHVDC transmission system has flexible and divers operation modes, so the characteristics of power fluctuation relate with different operation modes and types of faults after the fault in DC system. Based on the measured data of the UHVDC transmission system, the paper analyzes the characteristics of the DC system power fluctuation in case of fault, and establishes the external characteristic model. There are two basic impact characteristics models of UHVDC unipolar blocking, that is step and pulse impulse model. For the DC fault with complex power fluctuation, the external characteristic model can be superimposed by the step and pulse process. DC fault models are relatively simple in current simulation software, it is difficult to simulate complex power fluctuation when a fault occurs in the DC system. To this end, the paper proposes a simulation method of power injection external characteristic model data to analyze the influence of the DC fault on AC power system, applies this method to the actual system, and compares the simulation results with the measured data to verify the effectiveness of the proposed method and model.