Voltage Stability Analysis Of Shanghai Large Receiving-end Geid

Shanghai Grid is in the middle period of fast development and is gradually saturating. Shanghai Grid gradually shows the features of large receiving-end grid during this period. Generally considered, voltage instability may appear in the receiving-end grid within saturated system when the requirement of transmission and supply increases. Thus voltage stability assessment to Shanghai receiving-end grid in advance has great meaning.BPA is a simulation software for analysis and calculation which has great performance and is applied widely to power system. To the operation of large receiving-end grid, the essay brings forward the analysis flow of security assessment of static voltage on the basis of BPA. Moreover, apply the burgeoning grid computing technology to the assessment of voltage security and stability, carry out reasonable task partition and effective task scheduling, and design and accomplish the assessment of voltage security and stability based on the CAS (Client Agent Server) grid environment. The example of Shanghai grid calculating shows that the assessment of voltage security and stability based on BPA can acquire linear speedup, increase the speed and efficiency of analysis and calculation, and provide the analysis base for security and stability of the voltage of Shanghai grid.The essay applies the success of the assessment of voltage security and stability of CAS grid environment to Shanghai Grid and assesses the voltage security issue of Shanghai large DC power receiving in 2012. It stresses the situation of power flow distribution, district grid and reactive power reserve of Shanghai Grid. On this basis, the essay analyzes the voltage security limit under the normal operation and under the N-m situation of the whole Shanghai Grid and the voltage security limit of every district grid and it finds the weak region of Shanghai Grid. Finally, the essay evaluates the transient voltage security of Shanghai Grid by the aspects of AC fault, DC fault and ADC fault, finds the instability mode which causes the voltage problems.Energy-saving scheduling is more and more popular policy with the development of grid. So analyzing energy-saving scheduling has great directing meaning to the voltage security and stability of Shanghai Grid. On the basis of present Shanghai Grid and its feature of being a large receiving end, the essay uses the energy-saving scheduling math mode to analyze the influences from energy-saving scheduling math mode to Shanghai Grid by the aspects of static voltage stability and transient voltage stability, finds the possible weak region of Shanghai Grid after the application of the energy-saving schedule and the possible transient voltage instability modes.Under voltage load shedding is one of the most effective methods to avoid voltage collapse. The essay puts forward the concept of load synthesized factor on the basis of the multidimensional feature of load and puts forward the optimized under voltage load shedding mode on this basis. Moreover, the essay applies the mechanism of selection whereby the superior enterprises will prosper and the inferior ones be eliminated to the artificial fish-swarm algorithm, puts forward the method of improving the artificial fish-swarm algorithm and use the method to get the mode of under voltage load shedding.