Digital Substation Practical Research

With the development of integrated substation automation (SA) technology and microprocessor-based protections, electrical power system automation is highly promoted. But the communication protocols among IEDs (Intelligent Electronic Devices) produced by different manufacturers are different, the SA system will not be integrated well. Also, IEDs from different manufacturers are difficult to achieve interoperability. Maintenance and upgrading such a SA system may cost much resource and time. In a substation, many cables made with copper are used to transmit control signal and analog data, so it is impossible to make the IEDs insulated from the high voltage devices.The IEC61850 standard, electronic measurement transformers, intelligent control of high voltage electrical apparatus, computer network technology, etc, all these make it possible to build a digital substation. So, the thesis will study these key technologies and intelligence devices, and give a reference design project of digital substations.First, a digital substation model and main characters are formed in this thesis. Then a communication network construction principle of digital substations, including process buses and station buses, are developed. According with the principle, as an example of a general 220kV AIS substation, this thesis constructs a digital substation's layered communication network framework. The optimization scheme in the future with the support of the more advanced computer network technology is prospected. Based on the investigation of intelligence devices of digital substations, selection and configuration principle of devices is summarized. It is one of main issues this thesis concerns about. Thus, a practicable and credible design project of digital substations is entirely formed.Meanwhile, with so many non-digital substation SA systems and IEDs run in substations at present, this thesis analyzes how to run IEC61850 based IEDs and other digital apparatuses with non-digital apparatuses together in one substation. In the end,the effects of the digital substation and economic benefit is introduced.