Analysis Of Harmonic Winding Voltage Of Synchronous Generator By The Third Harmonic Excitation

Third harmonic excitation has already become a common excited means for synchronous generator at present. Yet, because the magnet field of triple harmonics is greatly affected by saturation of magnetic circuit, air gap, alveolus and pole shape, we are lack of accurate method to analyze and calculate triple harmonics excitation at present , and can not master no-load and load property of harmonic excitation system . Thus, according to Finite Element Theory , a lot of electromagnet field calculation are made for no-load and load synchronous generator by third harmonic excitation through ANSYS in this article , and the value and waveform of winding voltage are calculated by tooth flux method. And a new method ,named three-segment method , is present to analysis harmonic winding no-load property curve for synchronous generator by third harmonic excitation.According to Finite Element Theory, In this article, GUI ways and program ways of ANSYS software are introduced for the electromagnet field calculation of the electric machine. And half-period boundary condition is studied for the electromagnet field calculation. Based on ANSYS command ways,no-load and load electromagnet field calculation software is developed. According to this software,a lot of electromagnet field calculation are made for no-load and load synchronous generator by third harmonic excitation. Two calculation method , named FFT method and tooth flux method , are describe for e. m. f of winding and their advantages and disadvantages are analyzed. The first harmonic winding and harmonic winding no-load property curve are gained when field current is change.For mastering on-load property of the third harmonic excitation system . Thus , a new method to analyze harmonic winding no-load property curve of harmonic excitation synchronous generator , named as three-segment method , is presented in this article. The effect of pole-arc coefficient, air-gap, damper winding and magnet circuit saturation for no-load property of harmonic winding by it . So, in this article, we bring forward a new idea and method to analyze no-load property of harmonic winding of synchronous generator by third harmonic excitation.In the end, the waveform and value of electrical potential of winding and armature reaction property curve are gained through electromagnet field calculation, and compare it with the calculation result. They are identical in the rough. The research of this article brings forward a new opinion for analyzing the third harmonic excitation system and provide strong theory base and strong rational and practical design schemes for the design and the research of synchronous generator of third harmonic excitation.