Fast Dynamic Control of Medium Voltage Drives Operating at Very Low Switching Frequency—An Overview
Fast Dynamic Control of Medium Voltage Drives Operating at Very Low Switching Frequency—An Overview
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DOI：
10.1109/tie.2007.908540
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发表时间：
2008-03
影响因子：
7.7
通讯作者：
J. Holtz;N. Oikonomou
中科院分区：
文献类型：
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作者：
J. Holtz;N. Oikonomou
由大功率逆变器供电的中压交流电机在低开关频率下工作，以抑制功率半导体器件的开关损耗。因此，在设计驱动控制系统时需要特别注意。在矢量控制方案中，由低开关频率操作引起的信号延迟增加了不期望的交叉耦合效应。诸如前馈控制等现有方法无法充分补偿这些缺陷。改进是通过对机器和逆变器进行更精确的建模来实现的。介绍了一种具有复系数传递函数的适当控制器。低开关频率导致的高谐波失真是一种权衡。采用同步最优脉冲宽度作为备选方案，可以在不增加谐波的情况下降低开关频率。通过将谐波分量施加在最优空间轨迹上，消除了传统控制方法的不利影响。无差拍行为和完全解耦就这样实现了。在数学分析和实验结果的基础上，比较了上述方案的性能。
Medium voltage AC machines fed by high-power inverters operate at a low switching frequency to restrain the switching losses of power semiconductor devices. Particular care is thus required in the design of the drive control system. The signal delay caused by low switching frequency operation increases undesired cross-coupling effects in vector-controlled schemes. These are not sufficiently compensated by established methods like feedforward control. Improvements are achieved by a more accurate modeling of the machine and the inverter. An adequate controller is introduced, having a transfer function with complex coefficients. The high harmonic distortion due to the low switching frequency is a tradeoff. Using synchronous optimal pulsewidth as an alternative permits reducing the switching frequency without increasing the harmonics. The detrimental effects of conventional control methods are eliminated by forcing the harmonic components on an optimal spatial trajectory. Deadbeat behavior and complete decoupling are thus achieved. The performance of the aforementioned schemes is compared based on mathematical analyses and experimental results.