The Study Of The Relationship Between Synchronization Stability And Voltage Stability And Voltage Collapse

The structure of modern power grid is complex and its scale is large, but its structure is relatively weak, and the operation of the power system is more and more close to its limit state, which has brought to the safe operation of power system some new problems, and one of is voltage instability or voltage collapse caused by malignant accident lost partial load or blackouts. The mechanism analysis and stability measure between voltage instability and Angle instability is a very different nature, therefore, to distinguish the voltage stability and Angle instability is necessary.Due to power system causes tidal current transfer after disturbance, the synchronous generator power imbalance, even out of step, namely power collapse occurs, this paper analyzes the influence of active power and the system voltage, which is caused by the power system reactive power transferring, in single machine infinite system as the research object, is intuitive, convenient, and the influence of active power caused by reactive power is embodied in the change of the generator power Angle and the voltage of the machine. Got the conclusion that reactive power transfer will affect the active transmission and distribution and whether generator out-of-step and extent of the machine voltage are related to the size of the reactive power disturbance, and the relay protection of generator prospect is put forward, to perfect the generator relay protection, in order to avoid the synchronous generator out-of-step caused by reactive power transferring.Based on the critical voltage stability and the critical synchronization stability relations were discussed, this paper respectively considered the relationship under load according to the constant power factor and constant reactive power changing. When discussing the relationship between voltage collapse and the critical synchronization stability, this paper leads to the concept of reactive power support via a simple experiment phenomenon, and concluded that the relationship between voltage collapse and the critical synchronization stability is closely to reactive power support ability, especially under the condition of no line resistance. Finally, using numerical examples verify the validity of the proposed conclusion.Considering transmission line resistance is far less than the reactance, this paper will make no line resistance as a special case to consider, and the conclusion has certain guidance and reference value.