通过对典型交直流并联输电系统的仿真研究发现,在给定事故、直流功率及控制方式下,在发电机节点有功功率和电压幅值、负荷节点有功和无功功率以及直流传输有功功率的决策空间上,保证交直流并联输电系统大扰动短期电压稳定性的实用动态安全域(practical dynamic security regions,PDSR),在较大范围内仍可由描述各节点注入上、下限的垂直于坐标轴的平面、极少数几个分别对应于不同失稳模态的描述大扰动短期电压稳定性的临界超平面和平衡节点所对应的约束面围成。同时发现:当采用整流侧定电流和逆变侧定电压控制方式时,或者低压限流器的参数VL取值较大时,PDSR将扩大;当直流传输功率的不同、直流定功率控制(功率值不变)测控点选择不同和负荷中感应电动机所占的比例不同时,PDSR临界超平面具有平移性质。
A study on practical dynamic security regions (PDSR)of the typical AC/DC parallel systems shows that the short-term voltage stability PDSR can be expressed approximately by the vertical hyper-planes which are composed of the upper and lower limits of every bus injection,one or several critical hyper-planes which describe critical points of short-term voltage stability in injection space, and restriction planes of balance node, when the fault, DC power and DC control nodes are given. It is validated that short-term voltage stability PDSR would expand,if CC/CV (constant rectifier DC current/constant inverter DC voltage)control mode or high VL Of voltage dependent current order limiter(VDCOL)were adopted. In addition ,for the same fault, unstable mode and DC control modes ,the critical hyper-planes corresponding to different HVDC power, different power measuring site with same value and different induction-motor proportion in load are approximately parallel.