Research On Z-source/Quasi-Z-source Indirect Matrix Converter

The indirect matrix converters (IMCs) have attracted considerable attention in both academic and industrial areas. They provide bi-directional power flow, sinusoidal input/output current waveforms, and all-silicon-solution conversion with the absence of the dc-link capacitor. The desirable characteristics of IMC have become increasingly attractive for application in induction motor (IM) drives, military power supplies, and energy conversion, etc. However, the complexity of MC topologies makes the study and the implementation of suitable modulation a difficult task. Most importantly, MC has two main disadvantages. Firstly, it is sensitive to power source/grid disturbances. Secondly, the maximum voltage gain is limited to0.866due to its buck conversion characteristic. This dissertation presents three kinds of three-phase Z-source (ZS)/quasi-Z-source (qZS) IMC topologies, which overcomes the voltage gain limitation of traditional MC and also exhibits the inherent benefits of MC.Firstly, three kinds of Z-source/quasi-Z source IMC topologies are proposed, which insert Z-source/quasi-Z source network into input side of IMC. Meanwhile, the boost feature of these three topologies is analysis, and compare with the boost capacity of these topologies.Secondly, considering the switches frequence will be increased when the shoot-through vector is inserted into rectifier-end, this dissertation analyzes the influence of different modulation method for system switch frequency and input armonic, selects an optimal modulation strategy. At the same time, to solve the problem about common-mode voltage of matrix converter, this dissertation presents two methods reduce common-mode voltage.Thirdly, the dynamic modeling of the ZS/qZS-IMC is derived and the transfer function of system is given. The output response characteristics had been analyzed with change of ZS/qZS network parameters about the inductance, capacitance, inductance parasitic resistance, capacitance equivalent series resistance and shoot-through vector duty ratio. Meanwhile, the double-loop control strategy was adopted in this system. By redulating shoot-through vector duty ratio, the dc-link voltage control is achieve, which can increase the anti-jam capabilities and enhance robustness of the system.Fourthly, this dissertation gives the parameter design principles of ZS/qZS-IMC, analyses the current/voltage stress of passive components and power switch device, and give their loss calculation formula.Finally, this dissertation designs and implemented the ZS/qZS-IMC experiment platform by DSP and CPLD as the control core. Using the platform, we can verify the proposed ZS/qZS-IMC.