Design And Development Of Distribution System Microcomputer Relay Protection Device

Along with the rapid development and reformation of the smart grid system worldwide, the intelligent and automatic distribution system has become increasingly demanding. Microcomputer relay protection device, as the main automatic equipment that is used to monitor and protect power system, its intelligence and automation level will directly affect the level of the whole distribution system. In this paper, a detailed analysis on the distribution network composition and the protection system are conducted, then a new microcomputer relay protection device is proposed for distribution system. The hardware design, software design and protection algorithm are also narrated.Firstly, the composition of distribution automation is analyzed, the components of distribution feeder protection system are introduced, which together will help to illustrate the important role that microcomputer relay protection device plays in the distribution relay protection system. Furthermore, the energy supply system for distribution feeder protection is designed and solar-powered model is proposed.In the hardware design, the"DSP+MCU"dual-CPU architecture is used, which gives full play to the powerful DSP data processing capability and MCU event management capability, thus distribution protection requirements is fully meet. The DSP chip TMS320LF2407 from TI is selected as the key control core, three ADS8364 high-precision data acquisition chips are used as well, which together will be used to collect and calculate data. The MCU chip S3C44BOX from Samsung is selected as the protection core. The S3C44BOX is a high performance 32-bit ARM microprocessor, base on which the human-computer interaction interface, binary inputs/outputs interface are developed.In order to improve the reliability of microcomputer relay protection software system and facilitate the program maintenance and upgrading, theμClinux embedded real-time operating system has been introduced into microcomputer relay protection in this article. After analyzing theμClinux operating system kernel architecture, the migration ofμClinux to S3C44BOX is achieved, detailed information is provided as well. Finally, the user application program which includes the Self-test program, protection and judgment program, real-time data collection program, communication program, clock program and three-section current protection program are completed.In this paper, the tasks to design main hardware system, to develop software program and carry on debugging are accomplished. The system can realize the aim to protect a variety of common faults in the distribution system, which is also verified by the relevant experiments. The research and experiment result together indicate that the designed structure is reasonable, the technical protection requirements are meet.With high precision and high-speed communications features, the designed system can fully meet the needs of distribution system automation.