分频输电系统静态电压稳定性分析OA

[Objective]This paper systematically analyzes the static voltage stability and power limit characteristics of the fractional frequency transmission system(FFTS),exploring the variation laws and intrinsic mechanisms under varying frequencies and topological structures.[Methods]Based on the mechanism of static voltage stability and the continuation power flow method,the advantages of FFTS in static voltage stability are identified.The investigation reveals that the power limit shows both monotonic and non-monotonic trends as frequency decreases,depending on the network topology.Furthermore,the active power limit expression is derived based on the Thevenin equivalent circuit to elucidate the causes of non-monotonic variations.[Results]For a given topology,the static voltage stability of an FFTS is superior to that of the power system operating at power frequency.However,in specific topologies,the active power limit presents a non-monotonic characteristic of"increase-then-decrease"as frequency declines.This phenomenon originates from the coupling effect between the phase angle of the PV node and the system reactance.When this coupling effect does not affect the power limit,the power limit varies monotonically.[Conclusions]While FFTS offers significant advantages for static voltage stability,its power limits are highly sensitive to topological configurations.Consequently,system parameters must be carefully configured during the design phase.