Research On Hybrid Static Synchronous Compensator

Recently, with the capacity of power system increasing, the demand of reactive power and requirement of power quality increases at the same time. It is hard to compensate reactive power thoroughly by the traditional compensator. Static Synchronous Compensator(STATCOM) could supply capacitive reactive power and inductive reactive power continuously, so it can enhance stability of power system and power factor as well as power quality. On account of limiting of Power electronic device, it is difficult to design large-capacity STATCOM. So series technology and multiple technology and multi-level technology of device is researched, but there universally are the question of the engineering high cost.In this paper, An hybrid static synchronous compensator (HSTATCOM) is proposed on the basis of analysis of every kind of compensators, and the principle of HSTATCOM is researched in detail. The compensator which is controlled coordinately, is combined large-capacity TSC with small-capacity STATCOM. So the capacity of STATCOM is half of single statge of TSC capacity.Control strategy has great influence to characteristic of compensator and is important in research of reactive compensation. Basis on the analysis of principle and the comparasion of the strategy of TSC and STATCOM, the strategy of coordinate control is researched. By the means of deadbeat control, the HSTATCOM has good dynamic characteristic and unity power factor. To verify the validity of the control strategy of the HSTATCOM, simulation is done.By the simulation and parameter design of the HSTATCOM, a prototype is developed on the condition of low voltage. To control the prototype on the platform of DSP, digilal control is realized and the digitalization which simplifies the hardware design. Finally, a host of experiments testify the feasibility of the HSTATCOM and validity of the control strategy. The results show that the device based on the proposed scheme can improve the power quality effectively and almost all the required specifications are met, which gives a good start for further research.