Force commutated high power electronics

多年来，申请人已经奠定了理论基础，表明：(1)正弦脉宽调制（SPWM）下的强制（或自）换相转换器可以作为线性放大器工作；(2)调制带宽应小于载频的1/3。接下来的理论回顾是流行的空间矢量调制（SV-PWM）。线性只有在直流电压恒定时才有效，否则变换器是非线性的。近年来，申请人运用非线性理论来应用极点布置来改善动态特性。这个模拟的成功将被利用来实现实验实现。在工程方面，申请人开发了柔性交流传输系统（FACTS）和高压直流（HVDC）的pwm系列控制器。继续研究的方向是：利用固有的电压支持和独立的P-Q控制作为附加价值；将SSSC等多功能纳入高压直流站；通过在串联补偿中加入介电电容器来降低成本。这项研究计划有两个新举措。首先是研究FACTS和HVDC控制器如何将大型互联电力系统划分为原始的更小、更强的单元。甚低频失稳问题将是本研究的出发点。本研究将使用HYPERSIM， Hydro-Quebec的并行计算系统和电力系统仿真软件。第二项倡议继续研究双馈感应发电机的风能研究，并使其在变速交流驱动接近尾声。这项为期5年的提案涉及5个项目，每年将培训3名研究人员。总共将培养6至8名硕士或博士水平的研究人员。

SUMMARY Over the years, the applicant has laid theoretical foundations showing that: (1) Forced (or Self) Commutated Converters under Sinusoidal Pulse Width Modulation (SPWM) operate as linear amplifiers; (2) the modulation bandwidth should be less that 1/3 the carrier frequency. Next in line for theoretical review is the popular Space-Vector Modulation (SV-PWM). Linearity is valid only for constant dc voltage, otherwise the converter is nonlinear. Recently, the applicant has applied Nonlinear Theory to apply pole-placement to improve dynamic characteristics. This simulation success will be capitalized on to realize experimental implementations. On the engineering side, the applicant has developed controllers in the PWM-family of Flexible AC Transmission Systems (FACTS) and High Voltage DC (HVDC. Continuing research is directed to: deploying the inherent voltage support and independent P-Q control as added values; incorporating multi-functions such as SSSC into a HVDC station; reducing cost by incorporating dielectric capacitors in series compensation. The research proposal carries 2 new initiatives. The first is to study how FACTS and HVDC controllers can partition large interconnected power systems into their original smaller, stronger units. The problem of very low frequency instability will be the starting point in this research.This research will use HYPERSIM, Hydro-Quebec's parallel computation system and power system simulation software. The second initiative continues the research on doubly-fed induction generator for wind energy research and brings it to a close in variable-speed ac drives. This 5 year proposal fields 5 projects  which will be train 3 researchers every year. In all, it will train 6 to 8 researchers in the Master or Ph.D level.