Research On High Frequency Link Matrix Inverter

In recent years,with the continuous improvement of social life,various industries in the society have increasingly higher requirements for the performance of DC/AC inverters.At the same time,with the development of power electronic devices and new control technologies,the high frequency of inverter technology has also become a major research hotspot.The high frequency link inverter technology uses a high frequency transformer to significantly improve the working characteristics of the inverter,and has the advantages of high power density,light weight,high efficiency,and fast dynamic response.Therefore,this article mainly studies the high frequency link matrix inverter,which eliminates unnecessary intermediate DC links,simplifies the structure of the converter,and improves the operating efficiency of the system.First of all,starting from the back-stage matrix converter,according to the polarity of the output voltage of the front-stage full-bridge inverter,it is decoupled into two traditional three-phase voltage source inverters,so that the conventional voltage source can be inverted.The introduction of the control method of the converter greatly reduces the complexity of the converter control.Then the decoupling control strategy is theoretically deduced and proved from a mathematical point of view.Secondly,due to the particularity of the topology of the high frequency link matrix inverter,it is found that the use of conventional decoupling control strategies will cause the leakage inductance current of the high-frequency transformer to undergo abrupt changes during commutation and cause instantaneous voltage spikes.Therefore,this paper combines the decoupling control strategy and the SVPWM control strategy,and proposes a new type of high frequency link SVPWM control strategy.This strategy enables the leakage inductance of the high-frequency transformer to achieve natural commutation without causing voltage spikes when the load power factor angle is within a certain range,and the control strategy is verified by simulation.Next,based on the analysis of the working status of the high frequency link matrix inverter,this paper proposes a new soft switching control strategy for the highfrequency link matrix inverter to further reduce the switching loss and conduction loss of the high-frequency chain matrix inverter and improve the system efficiency;At the same time,the leakage inductance of the secondary side of the high-frequency transformer and the parasitic capacitance of the MOSFET are considered,and the phenomenon of voltage spikes caused by the resonance of the two is analyzed,and then the resonant voltage on the secondary side is suppressed by adding a flyback clamp circuit peak.The composition and working principle of the flyback clamp circuit and the design of its related parameters are studied,and the control strategy is verified through simulation.Finally,based on the previous research,further experimental analysis and research on the high frequency link matrix inverter.The hardware design includes switch tube selection,drive circuit design,high-frequency transformer design,and output filter design.At the same time,the EP4CE10F17C8 FPGA control chip is selected for software design and writing.Then an experimental prototype with a DC input of 50 V and a power of 200 W was built to verify the effectiveness of the two control strategies.