Study on deadbeat control strategy for grid-connected distributed generation system

This paper presents a deadbeat control strategy for DG inverters to achieve its grid cut-in control. This strategy uses the single-stage grid-connect inverter (inverter without DC/DC converter) in order to improve its efficiency, what´s more, it is easy to control. The DG inverter has to use a step-up transformer to obtain optimum voltage level to connect to the utility grid. Pulse width in one switching period is calculated using deadbeat algorithm. In this strategy the pulse width of a certain switching period is worked out consulting measurement parameters of the former switching period and parameters that predicted from parameters of former period. The switching period pulse can be worked out then. At last the control strategy is simulated with Matlab to validate its feasibility. The result of the simulation shows that the deadbeat control has many strong points: it is easy to control, responds quickly, connect DG with the utility grid at any time, achieves cut-in control without current impulsion , power factor is high and the power is controllable.