Study On The Application Of The Protection Based On The Principle Of Balance Of Energy

In the present power systems, though the protections are already perfect, such as current production, distance production and differential production, they are based on the mains-frequency phasor. In the extra-high-voltage long line, these methods cannot fully play the key role in the protection as before. So it is necessary to explore the new methods based on transient amount.The thesis analyzes the characters of the present circuit production and comes to a conclusion that in the extra-high-voltage long line, the distribution of capacitance and current influences the protection most, then promotes two kinds of new circuit production---The current differential protection based on Bergeron model, and the protection based on the principle of balance of energy.The thesis firstly gives us an introduction of the development of the compensation for the distribution of capacitance and current, and sets up a simulation model by a 300km circuit. Finally it is proved that after using the digital filter, compensating the circuit under the simplifiedΠmodel can improve the performance characteristic of differential production, reduce the performance threshold value, and increase the quick-action. And through the analysis of theΠequivalent circuit, we can get the character of the shunt reactor and lay a foundation for the research of the shunt reactor compensation.The thesis also takes the Bergeron model as an example, analyzes the errors which will appear during the emulation analysis, and find the solutions through the analysis of the sources of the errors, which can make a basic foundation for the following emulation research.The thesis finally introduces the basic theories of energy-balance production in details and proves the feasibility of main protection in the extra-high-voltage long line through the emulation research. Then it takes the compensation of circuit's distributing capacitance and current as a base, studies the influences of shunt reactor on energy-balance production. It shows that the shunt reactor cannot impact on energy-balance production through the different reflections of criterion of energy-balance production under two different conditions. One is with shunt reactor, the other is not. The energy-balance production against the extra-high-voltage long lines is a new method for circuit differential production. It has good prospects. The present study has laid a foundation for further verification of its feasibility.