High Performance Control of Single-Phase Full Bridge Inverters Under Linear and Nonlinear Loads

Abstract

Full bridge inverter are widely used as DC-AC power conversion interfaces in many areas such as PV application or interruptible power supply. The first and more important factor to evaluate the inverter is the quality of its output voltage. Indeed, this voltage should be sinusoidal with low total harmonic distortion (THD), even when feeding non-linear loads. In addition, the inverter is expected to have good transient response under load variation. This paper presents an enhanced control strategy to meet these requirements. The single-phase full bridge converter is modeled in stationary frame where the quantities are AC to make the system very simple without using any transformation. The adopted control is performed by using only one proportional regulator and only one measuring device to sense the output voltage. The injected voltage is obtained by the sum of the output voltage and a compensation term which is proportional to the error between the reference voltage and the feedback signal represented by the output voltage. The proposed control scheme is simulated and tested under linear and nonlinear load. It's found that the THD, steady-state error, response time of the output voltage still zero for any cases of connected loads.