Research On General Micro-Processor Based Protection For High Voltage Transformers

Basing on the summarizing of the evolvement and actuality of transformer protection and the requirements of transformer protection device used in high or extra high voltage case, this paper bring forward a total design of microprocessor-based protection for high voltage transformer. Further more, the key technique and development of general transformer device have been analyzed deeply.At the first, this paper introduces the evolvement and actuality of transformer protection, the principle of main and backup protection of transformer is retrospect. And the current problems and trend have been discussed in this paper. Then the paper discusses the design principles and function requirements of general device for transformer.Aiming at the realization of general microprocessor-based protection device using for large voltage transformer, the paper presents a efficient technical scheme. The protection device takes advantage of control word to alternate the connection mode of transformer. That solves the problems of flexibly cast and canceling of protection function, phase compensation of differential current and adjustment of balance coefficient etc. Adopting channel configuration based on mapping-principle, the protection device could configure analog and digital input/output freely. The special design fulfills the requirement of generality.The thesis has researched principle of transformer main and backup protection, and design a configure scheme in order to meet the demand of generality. By taking full advantage of ratio differential protection, sample value ratio differential protection, fault component differential protection, this paper form a holistic scheme of differential protection. This scheme has ability of speed, sensitivity, reliability, resisting TA saturation and anti-jamming.Then the paper introducing the system's hardware design and software design aiming at characteristic of general protection device. The hardware adopts high-capability chips (TIC6000 DSP and ARM920T) as its hardware platform .And the software adopts module design method. The protection program of general transformer protection device has been completed and tested. The result can fulfill the requirement of design.