【作者】 李欣；

【导师】 杨俊友； 邢作霞；

【作者基本信息】 沈阳工业大学 ， 电气工程， 2014， 硕士

【摘要】 依托国家电网公司科技项目(DKYKJ[2012]001-1)和沈阳市科学计划项目(F11-238-1-00)，本文针对双馈风力发电机机侧变流器产生的奇次谐波对发电系统的性能影响，分析谐波对双馈发电机有功功率、电磁转矩和损耗的影响程度。通过将各次谐波当做独立电源的方法，并结合定子、转子分开的等效电路，重点分析5次、7次、11次和13次谐波对发电机电磁转矩的影响。还讨论了双馈发电机运行状态改变时，变流器输出波形含有偶次谐波时，电磁转矩脉动的影响情况。仿真结果验证了谐波对发电机性能影响判断的正确性。首先，阐述了双馈感应发电系统发电机组的基本结构和运行原理，给出了双馈发电机等效电路和空间矢量图，并根据叠加原理将其变换为定子、转子分开的等效电路图。推导了理想正弦波下的双馈发电机的定子侧和转子侧的有功功率、无功功率和电磁转矩计算公式，分析了双馈发电机功率流动关系和稳态性能。其次，推导单相半桥两电平SPWM逆变器、单相全桥和三相全桥输出电压的双重傅里叶级数表达式，并分析单相和三相逆变器输出电压波形的谐波频谱。根据谐波频谱分析的结果总结出不同频率调制比F和幅值调制度M值对逆变器输出波形的影响规律。最后，从谐波对磁动势和转差率的影响出发，推导出忽略定、转子电阻的有功功率及电磁转矩计算公式，在此基础上得出各次谐波对输出功率和转矩脉动的影响规律。利用matlab仿真得出各次谐波的转矩脉动波形，并对变流器输出频率改变时，谐波对双馈发电机转矩脉动的影响进行分析研究。通过仿真结果验证了本文分析与计算方法的正确性。更多还原

【Abstract】 This thesis was supported by Technology Project of State Grid (DKYKJ[2012]001-1)and Program of Shenyang Science (F11-238-1-00), studied the performance impact ofmachine-side converter odd harmonics to power system, pointed out the influenceharmonics to DFIG active power, electromagnetic torque and loss extent. Analysisfocused the impact of5th,7th,11th and13th harmonics on electromagnetic torque, bythe method of harmonics as independent power-supply and combined with the equivalentcircuits of stator and rotor. Furthermore, thesis discussed the situation thatelectromagnetic torque ripple with inverter output waveforms contains even harmonics,when the operating status of DFIG changes. Simulation results show that harmonicimpact on generator performance is correct.Firstly, the thesis expounded basic structure and operation principle of DFIG system,showed DFIG equivalent circuit and space vector illustration, transform equivalentcircuit to circuit with stator and rotor separated according to the superposition principle.Calculation formula of active power, reactive power in stator and rotor sides andelectromagnetic torque under ideal sine wave were deduced, relation of power flow andsteady-state performance of DFIG was analyzed.Secondly, double fourier series expressions of two-level single-phase half-bridgeinverter SPWM, single-phase full-bridge and three-phase full-bridge were deduced.Harmonic spectrum of voltage waveform outputted with single-phase and three-phaseinverter is analyzed. According to results of analyzed harmonic spectrum, the rule ofinfluence of frequency modulation F and amplitude modulation M on inverter outputtedwaveform was summed.Finally, starting from the effects of harmonics on magnetic motive force(MMF) and slip, calculation formula for active power and electromagnetic torque were deduced. Onthis basis, the rules of influence of different harmonics on output power and torque ripplewere deduced. Torque ripple waveforms of each harmonics were analyzed by matlabsimulation. The simulation results verify the correctness of the analysis and calculationmethods in this thesis.更多还原