DEADBEAT-BASED PI CONTROLLER FOR STAND-ALONE SINGLE-PHASE VOLTAGE SOURCE INVERTER USING BATTERY CELL AS PRIMARY SOURCES

Abstract

This paper presents a deadbeat-based proportionalintegral (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 pulsewidth-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 230Vrms 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.