Power Grid Protection Scheme With Distributed Generation

As the energy demand is rising, the world energy situation is a cause for concern. At present, the coal, oil, natural gas account for a large proportion in the world energy consumption structure. The excessive use of fossil worsen the ecological environment and directly threat to human survival environment. With our country electric power industry vigorous development, the emergence of distributed power supply technology can reduce a part of energy demand,In order to realize distributed power accessing to the grid, distribution network protection scheme is crucial.In the paper, first introduces the concept of the distributed power generation system,development history and current situation of the development.Next, analysing several main types mathematical model of distributed power technology and distributed power grid form.Through the introduction and analysis of the traditional distribution network protection system, Through the introduction and analysis of the traditional distribution network protection system,using simulation software to establish the model of distribution network explain the traditional distribution network protection system with DG(distributed generation,DG) is not adaptive.thus provide theoretical support to the design of protection scheme.Based on the research of the wide-area protection and new type of relay protection, we design a wide-area protection scheme based on matrix algorithm. IED(Intelligent electronic devices,IED) used in the distribution network, the network is divided into intelligent electronic equipment related area.The IED related area formed the end and the first node matrix, through the relevant calculation with the end and the first node matrix to get the discriminant matrix, finally obtain a fault location results. In the second position of the fault location,fault location is more accurate by using the two location vector. The protection scheme to ignore two branch node, simplified calculation steps, at the same time, considering the special situation of related area correction to make fault location scheme is more comprehensive.Finally, considering the missing switch information, design a kind of protection scheme based on the missing switch information. By using the relationship between the fault alarm signal and the fault characteristic of the feeder switch, the distortion of the fault alarm signal is judged. through comparison of the on line terminal corresponding switch alarm information and the IED current direction,correcting the error message in the alarm signal.At the same time with distribution network grid partition area, setting the power direction of the distribution network system, using the front and end fault power direction to get the regional status and determining the fault occurrence region.Algorithm of overall process is simple,without taking into account the complex matrix calculation algorithm, at the same time, alsoavoid the intelligent multiple iterations of the algorithm. Shorten the search time trouble,improves the speed of the fault location.