Research On The Control Method Of The Inverter Based On Discontinuous Inductor Current Mode

Development of Modularized inverter technology needs better performance of the inverter. Along with the inverter system capacity's rising, the energy density of a single inverter is also growing. Under the conditions of high power density, how to achieve reliable and stable operation of the inverter, reduce the size and weight of modules and improve inverters efficiency become an important issue that must be considered. So this paper presents a control method and design of the inverter which is based on a discontinuous inductor current mode(DCM).The inverter deals with single-phase full-bridge or three-phase half-bridge topology and also with variable duty-cycle operation. This paper presents the performance of the inverter through the selection of a reasonable filter capacitors as energy storage elements, which can output sinusoidal voltage waveform, using the reference voltage tracking control mechanism. DCM mode control strategy maintains zero current switching at each turn on while the turn off of the switches is soft. So the inverter's loss is low.Firstly, the paper discusses the operation principle of the DCM inverter in detail and proposes the control method. At same time, a mathematical model of the DCM inverter is established to using for calculate losses. Secondly, in order to investigate the inverter power loss, the mathematical model of the inverter switching losses, conduction losses and filter inductor losses is also established and calculated. Compared with traditional CCM SPWM inverter, the proposed inverter has an advantage in terms of reducing the power loss. Finally, this filter design step and the DC bus voltage, switch and freewheeling diode selection program is discussed, and a simplified and easy to realized control circuitry is given. The simulation data and experimental results verify the feasibility of the proposed control methods and design solutions and confirm that the inverter has a good dynamic response, steady characteristics and resistance to load disturbance capability.