The Study On Black Start For Power Grid

Owe to the ever-increasing size and complexity of the power grids, nowadays the risk of massive blackout occurrence is much higher than ever before. It will be very difficult to recover the power system when it is down. Along with the robust economic development, the entire society relies on electric power more and more. Once large area power cut occurred, it would incur substantial social impact and huge economic loss, even threatening the national security. Therefore, it is quite necessary to research on the black start of power grid.Black start is the restoration after blackout of the entire power system. It is an effective measure to restore the power system when blackout occurs, on which the research work in this dissertation focuses. In this thesis, the status quo and the primary content of Black start research is introduced in the first place by demonstrating the system restoration strategy and the phases of implementation of Black start. Secondly, key technique of Black start is discussed in detail. The analysis mainly addresses the problems which may happen during black start of power systems, covering self-excitation, power frequency overvoltage, switching overvolatage, potential problems of the voltage and the frequency during system restoration, the security and stability of small system when instantaneous single-phase short current happens, loop closing, etc. Thirdly, with the Relational Matrix Analysis kept to the realistic power system practice, the paper innovatively utilizes the method of relational matrix analysis to get the optimal solution by orderly arranging and assessing various schemes, so that scientific and instructive decision can be provided to the dispatchers for reference. Finally, based on the practical situation of Tianjin power system, the paper analyses and discusses both the internal and outward power supply schemes of black start in detail, which stands a chance to contribute to draft the black start scheme for Tianjin power grid. In conclusion, the research work in this thesis is significant to restore power system after blackout as soon as possible.