The paper study the single-phase ground Fault Location. Which analysis neutral non-effectively grounded distribution network transient characteristics of single-phase. and verify the HHT method accuracy that through the actual system simulation of single-phase ground fault experiments .It proposed the fault localization criterion which is based on parameter identification. current single-phase ground fault detection and section targeting methods. The paper proposed the implementation which fault information is incomplete. It is help for theoretical study and power engineering..

Close attention has been paid to the power generation using renewable energy such as the widespread energy and solar energy. After the integration of large-scale renewable energy, more uncertain factors are brought to the power system, which badly influences systems planning and operation. The wind power, photovoltaic power and load are random but correlative, therefore, it is more logical to study the influence exerted by the integration of renewable energy when considering the uncertainty and it is meaningful to the power systems planning and operation. Based on the summary and survey of previous studies, the technical route of power system analysis concerning the correlation of wind power, photovoltaic power and load is proposed in this paper and some key technologies are discussed. The study of correlation offers valuable analysis and recommendations to the connection of large-scale wind and solar power base.

Cascading trips caused by flow transferring are the crucial reason for a lot of well-known blackouts. Aiming at the distance relay which is most applied in power grid, this paper puts forward an adaptive setting scheme to prevent cascading trips in complex power grid. In this paper, using two-port network model to fast calculating apparent impedance, and than calculating the apparent impedance change rate which is caused by flow transferring. According to the apparent impedance change rate modify the setting value which would contract the range of the impedance circle. After accomplishing the contraction, the relay action check will start. Through the process of modification and checking, the adaptive setting scheme which is not affected by the flow transferring will be formed. Taking the New England 10-unit 39-bus system which also used this method as the example, in this case, this method is confirmed by the BPA simulation.

Power flow transferring random occurred in power grid, so how to quickly identify overload line is a key problem to prevent cascading trips. This paper according to the bus self-impedance change rate rapid search the area which possible happened power flow transferring, and through the correction method for network equations checked the lines in this area whether overload or not, then selected the overload line caused by power flow transferring. Under the condition of known initial network parameters, this scheme according to the local network parameters modified to related calculation, improves the calculation speed, and has advantages for multipoint flow transferring recognition in complex power grid. Taking the New England 10-unit 39-bus system which also used this method as the example, in this case, this method is confirmed by the BPA simulation.

Doubly-fed induction generator has become one of most popular generators driven by wind due to its superior behavior in power system. Because of the different physical structures between doubly-fed induction generation units and normal synchronous units, they behave differently in the failure of power system. Based on the analysis of transient behavior of doubly-fed induction generator units, the transient stability of power system integrated with doubly fed induction generator considering different integrating points is discussed. The simulation results verify the validity of the conclusion at the last of this paper.