Optimal Location Of Emergent Reactive Power Compensation In Power Transmission Network

In order to satisfy progressive need of electricity, the structure of power system becomes more and more weaker, and the power plants tend to limit. The voltage will drop at certain buses expanding to voltage instability when the system operates under heavy loading conditions, which is usually triggered by system disturbance or faults. This instability can result in generation tripping which also causes system breakdown. The phenomena of voltage collapse have been observed in many countries and have been analyzed extensively in recent years.The relevant literature highlights that voltage collapse tends to occur from lack of reactive power supports in heavily stressed conditions. To Cater for the increased electro-demand of consumer, the requirement of reactive power compensation especially just after contingency shows its essentiality and necessity. Therefore, the voltage collapse problem is closely related to a reactive power planning problem including voltage collapse mechanism, contingency analyses and optimal formulation.As is mentioned in the front, When the power system tends to short term voltage instability, emergent reactive power compensation near the load center is very important and the demand to the reactive power compensator is to transform the power system to a stability balance operating point in the worst state. This paper proposes a new formulation for reactive power planning problem including the allocation (size and location) of ASVG. The objective function is to minimize the sum of installation costs, operating costs and increased cost in the system transition state. The calculation approach is the multi-genetic based migration strategy which can avoid disconverge problem of Benders decomposition method. The simulated results of AEP-14 bus system demonstrate the effectiveness of the proposed method.In the last part of the paper, LIAO NING power system based on the operation case in 2002 is analyzed. The result shows that the South of LIAO NING power network in heavy load conditions maybe occur voltage collapse due to weak relation with the powersystem. In the paper, PASAP program is used to simulate in several larger disturbance. Voltage collapse cases are analyzed and the realizable law is also applied to enhancing voltage security of the south of LIAO NING power network. The simulated results of the allocation of ASVG in the south of LIAO NING power network show that fast emergent reactive power compensation is supplied in the corrective state, higher stability limit as well as enhancement of power system damping is contributed.