METHOD FOR IMPROVING SYSTEM SMALL DISTURBANCE STABILITY AFTER ACCESS OF DOUBLE-FED UNIT

摘要

A method for improving system small disturbance stability after the access of a double-fed unit, comprising the following steps: building a mathematical model of the double-fed unit to calculate the sensitivity of an unstable mode or a low damping mode to a system matrix; locating several non-zero elements having the highest sensitivity to the mode in the system matrix and locating the most relevant parameter set; allowing each parameter to sequentially change within a preset range and observing the track of the changes in the eigenvalue of the corresponding mode; and comprehensively weighing and optimizing system parameters according to the eigenvalue change condition. The method improves a leading modal damping generated by improper selection of a controller parameter or a system parameter after the access of a double-fed unit, without the use of additional control means or any increase in cost. In addition, the method is highly targeted, thus avoiding an exhaustive attempt on all system adjustable parameters, greatly reducing the workloads, and improving calculation efficiency.