Development of Multi-Level Inverter using PAM and PWM for High Voltage and Capacity Motor Drives

本研究的目的是提出并发展一种新型的五位准双转换器，以应用于大功率应用，五位准转换器较三位准转换器具有更佳的效能。但五电平变换器存在分压点电位不平衡等问题，需要维持各电容电压。因此，我们提出了一种控制方法，使用多频带滞环比较器（MHC）的五电平整流器用作五电平逆变器的直流电源。该方法能够保持输出直流侧电容电压，使输入功率因数接近于1，并能将电能回馈给电力系统。提出了一种由五电平整流器到五电平逆变器构成的五电平双变流器系统的控制策略。所提出的方法具有将输出功率反馈到整流器侧的系统。该系统可以直接计算整流器输出的功率。该方法实现了更多的正弦波形， 关于我们 提出并研制了一种新型的1.5kVdc通勤列车辅助电源（APS）系统，该系统采用1.2kV通用IGBT作为开关器件，取代3kV以上的高压IGBT。由于IGBT的开关损耗相当低，APS中的载波频率为5kHz。通过使用没有缓冲电路的简单的双绕组Transformer磁耦合所有栅极线来实现串联连接的IGBT两端的电压平衡。为了确保这样的高载波频率是有效的APS性能，从滤波器的声级和输出电压的稳定性与突然变化的负载使用单相逆变器进行评估，然后与传统的载波频率进行比较。基于1.2kV IGBT串联技术，设计并搭建了实际应用的APS系统样机，并对其性能进行了评估。结果表明，与传统的高压IGBT逆变器相比，APS系统具有体积小、噪声低的特点，通用IGBT串联技术有望在各种高压IGBT逆变器以及APS系统中发挥作用。我们在IEEE IAS年会、IEEE电力电子专家会议上发表了一些研究成果，并在IEEJ工业应用汇刊和IEEJ电气电子工程汇刊上发表了论文。少

In this research, the purpose of our work is to propose and develop a new 5-level double converter for high power applications.A 5-level converter has better performance compared to a 3-level one. But 5-level converters have certain problem such as unbalance of potentials of dividing voltage point, so we need to maintain each capacitor voltage. Hence, we proposed a control method using multi-band hysteresis comparators(MHCs) for a 5-level rectifier used as a DC power source for 5-level inverter. The method is able to maintain the output DC-link capacitor voltage, keep the input power factor a near unity, and regenerate electric power beck to the power system. This paper proposed a control strategy for a 5-level double converter system constructed by 5-level rectifier to 5-level inverter. Proposed method has a system that feedback output power to rectifier side. This system can calculate power that a rectifier output directly. The proposed method realizes more sinusoidal waveform, and m … More ore balanced each capacitor voltage.We also presented and developed a novel auxiliary power supply(APS) system for the commuter trains with 1.5kVdc employing series-connected 1.2-kV general purpose IGBTs as a switching device substituted for high-voltage IGBTs over 3kV. The carrier frequency of 5kHz in the APS is realized due to considerable low switching loss of the IGBTs. Voltage balance across the series connected IGBTs are achieved by magnetically coupling all the gate lines using a simple two-winding transformer without snubber circuits. To ensure that such the high carrier frequency is effective on APS performance, sound level from filter and output voltage stability with a sudden changed load are evaluated using a single-phase inverter, and then compared with that of a conventional carrier frequency. On the basis of the series connection technique with the 1.2kV IGBTs, a prototype of the APS system is designed and built for the actual uses, and then its performance is evaluated at its rating specifications. From the results, it is confirmed that the APS system features smaller volume and lower sound level rather than conventional ones with the high-voltage IGBTs.The series connection technique with the general-purpose IGBTs is expected to play a useful role in all sorts of the medium voltage inverters originally employing the high-voltage IGBTs, as well as the APS system, in the future.We presented some results of this research at the IEEE IAS Annual Conference, the IEEE Power Electronics Specialist Conference, and also published the IEEJ Transactions on Industry Applications and the IEEJ Transactions on Electrical and Electronics Engineering. Less