Research On Seismic Function Failure Analysis And Security Control Of Power Supply System

Power supply system is an important part not only of lifeline system, but also of energy supply system. It interacts and inter-inhibits with other systems. The power supply system which is closely related to people's life influences people's production and living in a profound and widespread way. Once power supply system's function fails it will seriously affect the fundamental function of other systems, even will lead to fully functional paralysis of other systems, which will cause heavy losses and threat to people's lives and property. Since the mid 1960s, the power supply system seismic damage runs through every violent earthquake, and the loss becomes more and more serious, thus seismic security analysis and control of power supply system together with cost control are realistically a significant project.Power supply system is a complicated system which is composed of a large numbers and kinds of elements. The seismic security analysis model is got on the base of the study on the structure of the system, of some hypothesises and simplifications..In this paper, considering the particularity of the power supply system's post-earthquake recovery, the Fast Decoupling method is employed for load flow ananlysis. This method is obtained by improved the Newton method through decoupling the active power and reactive power. In this method, we catch the main power transmission influence factors and neglecte the minor according to the high-voltage power system's physical characteristic. The system's running parameters under normal condtion could be calculated by this method in short time. The sensitivity analysis method is employed for security analysis. In this method the line outage is viewed as disturbance of the system that running at normal condition. The sensitivity matrix is got from the Taylor series expansion of the electric system power equation, and the running parameters'increments are got from systems'power increments by the matrix.The system maybe run into emergency state after the security analysis, and it will be further damaged even lead to sytem's breakdown if some control measures are not taken. The aim of control is to make the system runed into safe state from emergency state. The Security Constrained Optimization method is employed in this paper. The minimum incremental cost is used as the objective function in view of the system running economy. The lines capacity, generators'output and nodes voltage limits are used as constraints. By adjusting the generators' output, which is calculated by the linear programming, the system is runed into normal condition and the operating cost is optimal. At last, the damage of San Francisco bay area power supply system in Loma Prieta earthquake in 1989 is used as example, the correctness and practicability of the methods are verified by this example. The Fortran and Matlab program of load flow analysis, security analysis, function failure analysis and security control are compiled. All the above can be used as theoretical basis of seismic security analysis and control and economic loss analysis of power supply system.