| The scale of power generation and transmission in China’s power system is expanding,and the number of new energy units integrated into the power grid is increasing.In this situation,the requirements of the power grid for operational stability are getting higher and higher,especially the increase of cross-regional transmission and large-scale combined power system makes the voltage stability of the power grid face a more severe test,so it is necessary to conduct in-depth research on the problem of excess reactive power and voltage fluctuation in the transmission process.At present,the use of generator in-phase operation to absorb excess reactive power on the line is one of the most economical and convenient means to solve the excess reactive power in transmission.The Asychronized Turbine Generator(ASTG)has stronger excitation regulation capability and better reactive power regulation capability than traditional synchronous turbine generators(STG),which is conducive to stable system operation.This thesis analyzes the principle and operating characteristics of ASTG excitation control,and further optimizes its excitation regulation system.Firstly,the working mechanism of the asynchronized turbine generator is clarified,the mathematical model and practical model of the motor are constructed,the decoupling principle of active and reactive power is demonstrated by using the phase diagram,and the mathematical model of the two-channel excitation control system is obtained on this basis to lay the foundation for the subsequent theoretical analysis and simulation experiments.Contrasting analysis of the constraints of asynchronized and synchronous turbine generators into phase operation,the key parameters affecting the reactive power increment of the asynchronized turbine generator are determined based on the reactive power equation,and the reactive power characteristics of the ASTG are verified to be superior to those of the STG through simulation.Secondly,a two-dimensional fuzzy controller is used to optimize the excitation system of an asynchronized turbine generator.Based on the basic principle of twochannel excitation control,the design of each aspect of the active channel fuzzy controller and reactive channel fuzzy controller is carried out,and the effectiveness and feasibility of the designed fuzzy controller are verified through simulation.Finally,to address the shortcomings of the two-dimensional fuzzy controller,an intelligent power function fuzzy controller is used to deepen and improve the ASTG excitation control system;meanwhile,the respective fuzzy rule functions are improved according to the characteristics of different regulation terms of the excitation system,and the secondary improvement is realized based on the Beetle Antennae Search(BAS)algorithm.The improved excitation system of the asynchronous turbine generator is simulated to verify its superiority. |
