Three-phase Converter Dynamic Model-based And Space Vector Modulation

Power electronics and motor driving have become a highly complicated cross-discipline with the rapid technical evolution in recent 40 years. With the increasing development of new devices and new technologies, the application of power electronics has been spread in various fields such as industry, commerce, military affairs and space travel. The power electronics have been the most critical technology in the application of power system, new energy power generation and power driven automobiles.Three-phase voltage-source PWM rectifier can achieve sinusoidal current of network, can achieve the unit power factor operation, can effectively suppress harmonic current and can realize the two-way flow of energy. These features make the three-phase voltage-source PWM rectifier to obtain a wide range of applications, especially in the high-power applications. Three-phase voltage-source inverter has been widely used in VFVS control, especially in the direct torque control. Direct Torque Control strategy takes the inverter and the motor as a whole by using closed-loop structure of electromagnetic torque. It is necessary to study the dynamic model of three-phase inverter and the space vector modulation technique based on this model.The overall performance and high reliability of power electronics devices require a good system design, which requires the power electronic devices to satisfy some certain static and dynamic indicators. Analyzing the indicators quantitatively and qualitatively requires the establishment of systematic model. The Buck and Boost converters in DC-switching converter are the basic topologies to construct power electronic devices. It is highly significant to study its structures and devices. In this article, the author sets up a model for the Buck converter using static and space averaging methods and based on this model, the author establishes another model for the voltage-source three-phase voltage converter through setting up a switching cycle averaging model for the three-phase rectifier inverter in static and rotating coordinate systems respectively and simulates the converter simultaneously. Pulse width modulation (PWM) technology is a control strategy most widely used for the AC output of power electronic converter, which works by changing the duty cycle (or pulse interval) of high-frequency switching converter to obtain the desired low-frequency average output voltage or current.Modulation technique has a central significance in nearly all the modern power electronic converters. The author deduces the computing methods and organizing ways of space vector in detail based on three-phase voltage-source converter and compares it with SPWM modulation and simulates it.Finally, the author summarizes his research work and illustrates his future research trends.