Research On Voltage Stability Mechanism Based On Small Disturbance Analysis

China's power grid architecture is toward a large-scale,long-distance,ultra-high pressure situation,the operation of the power system is getting closer to its limit state,while many areas there are high and low voltage electromagnetic network and the electricity load surge situation,these All to ensure the safe and stable operation of the power system put forward higher requirements.The voltage collapse accident,which occurred after the 1970s,caused great losses to the national economy.The research on the voltage stability in the academia gradually increased,and some achievements were achieved,but it was still lacking in the degree of stability A comprehensive understanding of its essential understanding,in the voltage instability of the mechanism analysis,research models and methods still need to continue to study.Because of the lack of uniform mathematical model and mathematical analysis method,the theory of voltage stability mechanism is not mature enough.On this basis,this paper puts forward and builds a dynamic and static comprehensive model which includes the three parts of the hair,the transmission,the armature reaction that highlights the change of the electromagnetic energy,and the various factors that influence the voltage stability.The angular stability analysis method is also analogous to other stability analysis methods chosen by the small interferometric method to analyze the voltage stability.At present,most scholars study the stability of the power system that the dynamic behavior of the power system is expressed as,but this study emphasizes the dynamic equation,adding a set of auxiliary equations,it is precisely because this group of auxiliary equations can accurately highlight the voltage instability Dynamic process,a complete description of the power system dynamic behavior of mechanical energy and electromagnetic energy changes.The differential algebraic equation of the former often can not show the change of the electromagnetic energy of the armature reaction.The transient oscillation of the synchronous machine Eq' is the core factor of the continuous decline of the terminal voltage.In this paper,the factors such as load characteristics,electrical distance,transmission network power transmission limit,OLTC dynamic characteristics and so on affect the voltage stability.However,this paper focuses on the sudden increase of the reactive current of the synchronous machine when the system is subject to small interference Large,due to the inherent characteristics of the synchronous machine itself,even without considering the excitation of the machine side of the case,there will be a transient potential drop,thereby increasing the machine terminal voltage(network node voltage)continued to decline when the serious voltage collapse.Finally,the stability of the voltage from the physical point of view and the phenomenon of the definition of power system power stability is synchronized with the mechanical energy stored in the release of the phenomenon.The voltage stability of the power system is the influence of the free component attenuation on the potential and the change of the demagnetizing magnetic field and the voltage drop of the transmission network caused by the non-abrupt change of the electromagnetic energy in the synchronous machine.But also to improve the voltage stability measures to provide theoretical guidance.