一种基于电气量变化特征的同步发电机失磁故障保护方法
By adopting a synchronous generator demagnetization protection method based on the characteristics of electrical quantity changes, the method monitors electrical quantity changes in real time and calculates demagnetization index, which solves the problems of slow or non-operation under partial or light-load demagnetization and false operation under system oscillation in existing methods, and realizes fast and reliable demagnetization fault detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NORTH CHINA ELECTRIC POWER UNIV
- Filing Date
- 2026-04-20
- Publication Date
- 2026-07-17
AI Technical Summary
Existing synchronous generator loss-of-excitation protection methods based on impedance principles are slow to operate or fail to operate under partial or light-load loss-of-excitation conditions, and are at risk of false operation under system oscillations. They also cannot effectively distinguish between loss of excitation and system stable power oscillations.
A protection method based on the characteristics of electrical quantity changes is adopted. By acquiring the changes in negative sequence voltage, effective voltage value, reactive power and power angle at the generator terminal in real time, the loss of excitation index is calculated, and the operation is carried out under the condition of meeting the criteria and delay. Negative sequence voltage blocking is introduced to prevent false operation of asymmetrical faults, and the system's lowest oscillation frequency is used to set the delay time to prevent false operation.
It enables rapid and reliable detection of demagnetization faults unaffected by load and degree of demagnetization, prevents false tripping under asymmetrical faults and system oscillations, and improves the speed and sensitivity of protection.
Smart Images
Figure CN122051880B_ABST