Study On Steady-State Operational Character And Mathematical Model Of Unified Power Flow Controllor And Experimentations

Power industry pay attention to Unified Power Flow Controllor for it's excellent ability of optimizing power system. As part of the research under the project "Unified Power Flow Controllor for Optimizing Power System Operation and Improving System Stability"(No. 0322014-4), which is supported by Key Technologies R&D programme of Guangxi. This dissertation not only investigates the steady-state operational character of UPFC and builds it's mathematical model, but makes the experimentation device for researching some technologies about UPFC.Based on special physical structure of UPFC, this dissertation studies the relation between controlled method of power eletronical inverters of UPFC and transfer direction of energy in UPFC, which is thinked about the character of series-mounting transformer and parallel transformer. And pointing out the right way of UPFC steady-state operation, which is Pulse Width Modulate method for voltage control and energy is transmitted from parallel side to series-mounting side.While power electronical inverters are controlled by SPWM of voltage method, the key to mathematical model of UPFC is accurate current relation between power electronical inverter's one side and another side. This dissertation resolves this question by "Inverter Transfer Function". Pointing out UPFC is to run in net compensation or terminal compensation. Meanwhile, the single-phase compensation and the three-phase compensation are discussed in this dissertation.As foundational elements of UPFC study, some questions are discussed in this dissertation, which are the principle of reactive power compensation based on power power eletronical apparatus, and some questions about PWM. For instance, the power frequency error of SPWM waves is more harmer to active inverters, like UPFC, than to passive inverters, which's effects are discussed and compensated methods are gave in this dissertation.The method of simulation in study course and the method of physical experimention in conclusion testify. The conclusion and the new viewpoint of this dissertation are pointed out in the ending.