| In recent years, the technology of electricity network development rapidly and the size of the network expand continuously. There has basically formed a special high-voltage, ultra-long distance, large transmission capacity modern power system at the moment. However, with the growing of high-voltage transmission lines, as well as a sharp length increase of the cable-lines, and the capacitance between the transmission line and ground will also increase accordingly. During the low power consumption such as holidays, late at night, there may be much more capacitive reactive power in the system. Which caused the voltage of some hub nodes increased over the normal rating.It is an economical and effective way to solve this problem by making some generators under leading-phase operation, and there have been many successful examples. However, with the depth of leading-phase increasing, the system stability reduced accordingly. Which increased instability of the system to some extent.In this thesis, we discussed the status of the subject domestic and abroad firstly.Outlined the theory of leading-phase operation briefly and probed the restrictions.Then analysis the theories of the system transient stability briefly, and discussed the mathematical model of system components. Discussed the simulation principles and processes of PSASP. Nextly using the power system analysis software PSASP calculated the normal mode and leading-phase mode power flow of Henan province.Basing on the normal mode simulation results, simulated the transient stability of power system. During the simulation, we set the same fault at the same place to analysis the power angle curve, as to determined the transient stability of the system.Basing on the analysis of simulation results: there is little influence of single-generator leading-phase operation to the distribution of flow on the entire network. Only little reactive power changed on the transmission lines near the leading-phase node. Single-generator leading-phase operation may reduce the transient stability at the same fault. To keep the safety of the transient stability, only from the security point of transient stability, there should be different extreme phasesfor different generators. To solve the problem of too much reactive power during light load period, considering to avoid single-generator leading-phase deeply, At the end of this thesis, proposed a method using multi-generator leading-phase together instead of sing-generator leading-phase deeply, proposed an improvement measures research direction. |
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