Hierarchy Optimization Design Of The Foundation Of Steam Turbine-generator Under Variability Loads

Electric power is China's economic lifeblood. Keeping the operation safety of the gridand the power stations smoothly is essential to support sustainable growth. People alwaysconsider steam turbine as heart of the power plants. The steam turbine must have favorablevibrancy characteristic to ensure it run safely. With the increase of the volume of steamturbine and the rapid development of nuclear power plant, the vibration of the foundation ofsteam turbine is restricted strictly. The dynamic optimization design of the foundation ofsteam turbine becomes an important front topic all over the world.Until now, there are many studies about dynamic optimization for the determinacystructure; that is to say, the structure's parameters and loads both are determinate. But intrue-life, many factors have its randomicity. So traditional method isn't fit the request inengineering.Hierarchical optimization technique is an important method, which decomposes acomplex optimum problem into a set of simplex optimization problems to be easily solved.Use of hierarchical optimization technique in structural optimization design can reduce thestructure weight and improve the efficiency of calculation.In this paper, hierarchical optimization method is used to solve the dynamic optimizationproblem of the foundation of steam turbine. The optimization problem is divided into twophases. The two phases process alternately. The results of the examples show that the methodis valid and rational. A new model based on reliability is presented. Through the equivalenttreatment, the original probability constraints are changed into conventional constraints inform. Numerical results are presented to demonstrate the effectiveness of the method.