Deadbeat-based PI controller for stand-alone single-phase voltage source inverter using battery cell as primary sources

This paper presents a deadbeat-based proportional-integral (PI) controller for stand-alone single-phase voltage source inverter using battery cell as primary energy sources. The system consists of the lead acid battery, third order Butterworth low pass DC filter and AC filter, H-bridge inverter, step-up transformer, and also a variety of loads as well as its sinusoidal pulse-width-modulation (SPWM) deadbeat-based PI controller. In this paper, two simulation case studies have been carried out which are the abrupt load changes from 400W resistive load to 500W resistive load and also from 400W resistive load to inductive load of 500W 0.85 power factor lagging. From the simulation results for both cases, the state-of-charge (SOC) battery is decreasing to supply power to the different type of loads, yet the battery voltage remains constant at about 36V and also the battery current exhibits smooth ripple despite current spikes produced by the H-bridge inverter so as to prolong the lifespan of the battery. It shows that the DC filter performs satisfactorily to isolate the current spikes generated by the SPWM controller and H-bridge inverter. Besides that, even though the load varies for both cases, the sinusoidal inverter output voltage can be tracked and maintained at 230V_rms with 50Hz frequency within few cycles from the instant the load changes as well as low THD_v content of 1.53% and 2.78% respectively. This indicates that the controller proves its robustness and stiffness characteristic in maintaining the output load voltage at desired value to supply the power for variety of loads with minimum THD_v.