Study On Quasi-Z-source Dual-output Two Stage Matrix Converter

Along with the development of the rapid development of in papermaking, textile, urban rail transit and steel, people’s control demand is more and more high for more than one motor high performance control demand at the same time, single motor control has already can’t satisfy people’s needs. But at present, a lot of traditional machine control system is generally composed of multiple three-phase voltage source inverters in parallel, a inverter drive an electric motor alone. With the development of power electronics technology and power electronics, double ac motor drive system is moving toward the direction of miniaturization, economize and energy-saving, so how to reduce the size and cost of double output power converter, how to improve the reliability of double output two-stage matrix converter is the trend of future research. Compared with the traditional converter covering arm, copological structure of the system is more compact, and increase the stability of the system. But the topology exists inevitable shortcomings: first of all, the output characteristics are greatly influenced by the input characteristics, then the total maximum voltage transfer ratio is 0.866. This paper put forward over the years of Z- level inverter source impedance network is introduced into the covering arm TSMC, by using the properties of quasi Z- specific source network, solved the covering the arm level inverter TSMC some defects existing in the topology structure itself.A Quasi-Z-Source Dual-Output Two Stage Matrix Converter topology and its control method is proposed. Compared with conventional dual-output two-stage matrix converter, the proposed topology has less power electronic devices, higher voltage transfer ratio, and eliminate the dead time of the power electronic devices. This converter which consists of a rectifier stage, a Quasi-Z-source network and a five-leg inverter stage can supply for two three-phase loads independently. The topology can reduce the Z-source capacitor voltage stress greatly and has inherent limitation property for inrush current. Compared with conventional Z source net, the quasi Z source net has overcomes the shortcoming, namely that the input current is discontinuous in the boost mode.Finally, the paper constructed the QZS-DO-TSMC experiment platform. The experimental platform consists of two parts, software system and hardware system, the software part with the DSP and CPLD as the core;the hardware system mainly includes the input filter circuit, the main switch circuit, drive circuit, signal conditioning circuit and auxiliary power circuit, etc. In this paper, the proposed topology was validated by experimental platform and modulation strategy is effective and feasible.