Study On Simulation Of High-rating Generator Stator Ground Fault Protection And Setting Calculation Software Of Generation Transformer Unit

The total electricity consumption of China had been reaching 55500 billion kW·h in the year of 2015, continuing a great increase in the demand of electricity. China will still be in the stage of industrialization, the huge energy consumption and power demand is the most important feature of this stage. Relay protection is the first line of ‘the three lines of defense of power system', playing a very important role to guarantee the security and stability of power system when a failure or disturbance occurs the power system, the large-scale generator transformer unit is an important component of power system, the lots of principles of relay protection, many differences of calculation, the huge tasks of the whole set calculation and the complicated setting work has promoting the intelligent computing of the whole set come into use. This paper will analysis the stator ground fault of the generator, which is the most likely to occur, research the protective value and the way to achieve the setting calculation software of the large-scale generator transformer unit.Now the capacity of the generators which are commonly used in our country is above 600 MW.The price of the large-scale generator transformer unit is very expensive, and its normal operation is the basis for the stable operation of the whole power system, the single phase earth fault of generator stator is the most common fault form of the generator which is very easily to lead to a huge accident of the power system. First this paper analysis the electrical characteristics of the single phase earth fault of generator stator and research on the response capability of the 100% stator winding of single phase earth protection to the single phase earth fault of generator stator. And analysis the sensitivity of the 100% stator winding of single phase earth protection on paper using the simplified model of the generator,and also simulate the generator's single phase earth fault by matlab, to test and verify the sensitivity of this protection.The requirement of relay protection setting calculation software for the large-scale generator transformer unit becomes more and more obvious, because of the big assignments, the long computing cycle and the different setting ways owing to the different setting habits of setting workers. This paper will summarize the steps and processes of the setting calculation of the large-scale generator transformer unit, analyze the function of the setting calculation software and study the realization of the setting calculation software based on the setting calculation work of a new builded electric power plant named Longbeiwan of Hubei province.The way to develop program the setting calculation is oriented to the protection device, which is based on the easy and simple operation because of the large amount of relay protection devices and the different protection principles of different manufacturers. The software has several modules such as the protection configuration module, the protection device selection module, the basic values logging module,the setting calculation and the setting value module and so on. Research on the practicability and the generality of the software to make sure it can be used in practice and can be extended in a large area.