The Research And Design Of 110KV Line Microcomputer Protection Based On PCB Electronic Current Transducer

With the development of the power system to large capacity, extra-high voltage and ultra-high voltage, the requirements of miniaturized, intelligentized, high security electric power equipments are higher in power system, but the routine transformer is difficult to satisfy the application of power system development requirements because of complex insulation configuration, huge volume, high price, magnetism saturation, ferro resonance and small dynamic range.The new type of electronic transducer based on electronic computer and photoelectric sensing technology has become a research focus due to its obvious advantages such as anti-electromagnetic interference, wide measurement range, small volume, light weight, low cost and convenient installation.The electronic transducers have been used which will replace electromagnetic transformer gradually and become development direction in future.On the bases of looking up the amout of doucments of domestic and abroad,this paper analyzes current situation of electronic transformer and structure principle of several mainstream sensor devices with its application situation,advantages and disadvantages.It also describes the characteristics and advantages of PCB current transformer and make a depth analysis of its structure and anti-interference principle.A design of new microcomputer line relay protection equipment based on PCB electronic current transformer was introduced.The device adopted modularity design which mainly includes protection module, MMI module,communication module,switch input module,swith output module and power module each of which exchange information by internal CAN bus network.The system adopted double CPU structure.The composition structure and each module of the equipment was analyzed and the software programming of microcomputer protection system including main contents and flowchart was introduced.In addition,the main interference sources of microcomputer protection device was analyzed and put forward a comprehensive set of anti-jamming measures.The protection device using PCB current transformer show wide measuring linearity, high sampling precision and using one kind of sensing element to effect a simultaneous realization of measuring and protecting data acquisition.The shortcom -ings that current transformer of present protection device have large volume and easy to be saturated is overcame.This solution can realize automatic production and have important use value and practical significance.