Analysis On The Influence Of The Harmonic Generated By The Converter Used In Pumped Storage A.C.Excitation Generator-Motor

Because of the ability to adjust the peak and frequency of the grid,the strategic significance of the security to accident and economic benefits,the pumped storage power station has got a rapid development,and the high-power AC excitation generator-motor is a power plant unit which is very suitable for pumped storage,cause it can be run in different circumstances include generator and motor and is capable of achieving two-way flow of energy and four-quadrant operation of the motor,which is actively studied by scholars in our country and a model has been produced by a relative company after a serious research on that.Harmonics generated by the converter on the rotor will do a lot of affect to the machine,that is what this paper mainly talking about.Firstly,we need to set a strategy of which kind of topology suited in high-power occasions is going to be used in this pumped storage machine,and then we decided the diode clamped three-level converter is quite suitable,and then analysis the harmonic characteristics by mathematical theory to analyze the relationship between harmonic output characteristics and topology and related control strategies,motor parameters and so on.Next,this paper analyzed the amount of the main harmonics of a model whose power is 3MW by using the software Matlab/Simulink,conclusion says that both harmonics such as low frequency part,switching frequency part and double switching frequency part is very small,0.5%-1% equivalent to the base frequency part;the influence of the harmonic which will led to loss,pulse torque,electromagnetic vibration on the motor is discussed then,stranded loss and core loss caused by harmonics is 0.12% and 2.18% amount of the base frequency current,electromagnetic vibration of low-frequency and high-frequency is 1.0004 and 1.0009 times to the base frequency current,lastly,a simulation was done to the 3MW model by using the method of Finite-Element-Analysis,and got a conclusion that influence caused by harmonics generated by converter on the rotor is not serious and can be ignored.The summary of the full paper is at the last.