【作者】 佟为明；

【导师】 程树康； 徐会明；

【作者基本信息】 哈尔滨工业大学 ， 电机与电器， 1999， 博士

【摘要】 随着电力电子器件的迅速发展,PWM 逆变器也在交流变频调速系统、UPS、交流稳压电源、中频电源及其他各种电力电子装置中得到了越来越广泛的应用,它所产生的谐波对外界的危害亦日益严重。本文在综述了用于逆变器的各种PWM 技术抑制谐波效果的基础上,对其中抑制谐波效果最佳的技术——特定消谐技术进行了深入研究,同时对目前应用最广的SPWM 电压型逆变器的谐波问题进行了定量而系统的分析。根据SPWM 的基本原理与付立叶级数理论,建立了SPWM 电压型逆变器输出波形的数学模型。通过理论分析与计算,得到了其输出谐波在变频变压过程中的分布规律,找出了SPWM 技术所存在的谐波问题,为SPWM 技术的有效应用提供了理论参考。在阐述了特定消谐技术的基本原理之后,系统地总结了特定消谐技术的特点。特定消谐技术中,表征基波及各次谐波幅值与开关角关系的方程组为非线性超越方程组,一般只能采用牛顿迭代法等数值方法求解,而解的收敛性取决于所给初值的正确与否。根据低阶问题的初值的试探与总结,找到了给初值的规律;通过编程计算,得到了开关角随基波幅值变化的轨迹及开关角在某一基波幅值下的具体数值。对于三相逆变器,共解出两组解。开关角的求得,解决了制约特定消谐技术普遍应用的一个关键问题。为了了解特定消谐技术中实际输出波形的谐波抑制性能,建立了包括功率开关管的开通时间与关断时间﹑加入的死区时间的实际输出波形的数学模型,分析了它们对基波及各次谐波的影响,研究了死区时间的几种加入方式,从而为特定消谐技术的工程实现提供了重要的理论依据。通过对特定消谐技术中开关角的分布规律及在提高输出波形质量和效率时所遇问题的研究,提出了省略开关角对及省略窄脉冲的优化策略,达到了便于硬件实现、功率开关管的损耗较小、而消除的谐波次数较多的目的。这对于充分发挥特定消谐技术的优越性、将其更快、更好地应用于工程实际具有十分重要的作用。研究了特定消谐式逆变器在线变频变压的各种实现方案及其优缺点,并更多还原

【Abstract】 With the rapid development of the power & electron parts, PWM inverter is applied ,on a larger and larger scale ,to AC frequency control system﹑UPS﹑AC regulated power source﹑medium-frequency source and other power & electron installation ,but hazard of harmonic produced by inverter get more and more seriously to outside installation. According to summing up restraining harmonic effect of PWM techniques utilized in inverter , selective harmonic elimination technique(SHET) which has the best effect on restraining harmonic is profoundly studied in the paper ,and at the same time the harmonic problem of SPWM voltage source inverter which is applied on the largest scale at present is quantitatively and systematically analyzed . Based on SPWM basic principle and Fourier series theory , the mathematical model of output waveform of SPWM voltage source inverter is built .Through theoretical analysis and calculation ,distribution regularity of harmonic which inverter produces during variable frequency and variable voltage is obtained ,and harmonic problem existing in SWPM technique is found ,and these above provide theory reference for valid application of SPWM technique . The character of SHET is systematically summarized after expounding basis principle of SHET. In SHET ,equations which represent relation of fundamental component and preparatory eliminated harmonic components are a system of nonlinear , transcendental equations that require the iterative Newton-Raphson matrix method for its solution ,and convergence in solution depends on whether or not starting value given is right .By means of trial-and-error method of starting value in low order matrix ,assignment regularity of starting value is found ; Through calculation by means of programming , the track of switching angle changing with fundamental amplitude and value of switching angle under some fundamental amplitude are obtained .With regard of three-phase inverter ,two groups of solution are acquired . Acquiring value of switching angle settles a key problem which hampers wide-range application of SHET . In order to understand refraining harmonic effect of real output waveform in SHET ,the mathematical model of real output waveform in which the factors involved in turn-on time ﹑turn-off time ﹑added dead zone time of switching angle are taken into account is built ,and their effect on fundamental component and all order harmonics is analyzed ,and methods of adding dead zone time are studied ,and these above provide important theoretical basis for industry application of SHET . Through studying distribution regularity of switching angle in SHET and the problem found when improving quality and efficiency of output waveform , optimal strategies that double switching angles and minimum pulses are ignored are proposed , the goal that hardware circuit is convenient to be made and more harmonics are eliminated by using less loss switching transistor is reached .This plays pretty important role in the fact that advantage of SHET is exerted and it can be applied ,better and more quickly , to industry application. All design schemes and their advantage and disadvantage of on-line variable frequency and variable voltage of selective harmonic elimination inverter are studied ,and the possibility of on-line calculating switching angles is discussed ,and these above establish fundament for design of selective harmonic elimination inverter . Finally , the conclusions on output waveform and its spectrum diagram of selective harmonic elimination inverter drawn from experiments are shown to be in good agreement with theory . This research plays greatly theoretical and applicable role in extended industry application ; At the same time ,it will greatly promote the development of efficient and reliable supply electric in our country , and carve out a important way of utilizing power more efficiently and less pollutantly.更多还原