含规模化新能源的交直流大电网动态无功储备快速精准评估，是抑制连锁故障、保障安全运行的重要手段。快速精确评估，需在“时间”上考虑毫秒级动态过程，在“空间”上计及广泛分布的新能源机组，并实现整个电网所有预想故障状态的快速“优化”计算。传统方法存在模型精度低、求解速度慢的缺陷，难以满足实际大电网评估需求。.本项目以动态无功储备评估的快速、精准为目标，以降维等值为创新思路，根据换流站动态过程快、新能源场站机组分布广、大电网优化规模大的特性差别，从降低系统“刚性”、系统维度、系统规模三方面着手，提出基于频域主分量的时间降维、基于状态归并的空间降维、基于电网自适应暂态分区的优化降维方法，给出评估误差的置信范围，用实际电网验证所提方法的有效性。.本项目方法能兼顾评估问题的速度与精度，弥补传统方法无法精确刻画三相不对称故障、新能源机组动态特性的不足，有效提高计算精度、为交直流大电网安全运行提供保障。

Quick and accurate dynamic var reserve assessment (DVRA) is a crucial way to prevent cascading trip faults and guarantee secure operations in large-scale hybrid AC/DC systems. Quick and accurate DVRA technique needs to consider the dynamics at milliseconds time level, needs to consider the all renewable power generators which are widely distributed, and needs to achieve the fast computation under all N-1 contingencies of the bulk power systems. Traditional approaches suffer from the lower assessment accuracy and higher computational burden, which cannot meet the real DVRA requirement..Therefore, this project aims to both guarantee the computation speed and accuracy of DVRA, uses reduced-order equivalent theory considering the characteristic differences of fast converter stations’ dynamic process, widely distributed renewable power generators and large-scale optimization problem of bulk power systems, to propose a time reduced-order equivalent approach to reduce the system stiffness by using a frequency domain principal component extraction technique, to propose a spatial reduced-order equivalent approach to reduce the system dimension by using the state-merge technique, to propose a optimization reduced-order equivalent approach to reduce the system scale by using the adaptively transient zone partition technique, respectively. The assessment error confidence intervals are then derived. Finally, the proposed DVRA approach will be tested using the operational data in real power systems..The proposed DVRA method both guarantees the accuracy and efficiency, overcoming the current shortages which cannot accurately assess three phase asymmetric fault in nearby area of the DC converter stations nor considering the operation details of large-scale integrated renewable energy generators. The proposed method also efficiently increases the computational accuracy and decreases the DVRA computational difficulty, which are useful and helpful to guarantee the secure operations of hybrid AC/DC bulk power systems.