Study And Design Of Excitation Power Supply Of A.C.Excited Generator

There is a broad prospect for Alternating Current Excitation Generator (ACEG) in improving the stabilities of extra-high voltage power system and in constant frequency generation with variable speed, by using the three-phase alternating current excitation and realizing independent regulation of active power, reactive power and rotate speed. It is the key point for ACEG to play good regulation performance, agility and reliability of operation that using appropriate excitation control strategy and excellent excitation power supply. In this thesis, several excitation power supplies for ACEG are contrastively analyzed based on the power balance of ACEG and dual-passage excitation control strategy of dynamical synchronous reference frame. Three-phase symmetrical alternating current, dual direction power flowing and input and output current of low harmonics must be offered by excitation power supply. According to such characteristics of power supply, the dual PWM control AC-DC-AC voltage source converter is proposed as the excitation power supply of ACEG.. In this thesis, the work principle, mathematic model and control algorithm of the converter are analyzed in detail and a simulation model of ACEG system excited by the converter is established and calculated by using Matlab/Simulink. The mechanism of harmonic increments caused by power device forward voltage drop and DC-link capacity voltage variety are analyzed in detail, and the compensation algorithm are proposed. According to the characteristics of the converter, the system design scheme based on the digital signal processor (DSP) and intelligent power module (IPM) is proposed, and the hardware design of excitation power supply is accomplished. The software design and system debug of the converter are also accomplished by using assembly language program design on TMS320LF2407A. At last, experiment results are used to verify the basic control strategy of the converter and analyze the stable and transient performance of the converter. The results in this thesis will be helpful to design the excitation power supply system of ACEG.