On a Bidirectional Adapter With G2B Charging and B2X Emergency Discharging Functions

This paper presents a bidirectional adapter having the functions of charging and discharging, providing 110 V/60 Hz emergency output from the battery embedded in a laptop computer, in electric vehicles, in an uninterruptible power supply, or in other possible appliances. The developed adapter possesses the grid-to-battery and battery to any emergency need (B2X) capabilities. In discharging mode, a front-end dc/dc converter is equipped to establish boosted dc-link voltage from battery for the followed inverter. Then, an H-bridge single-phase inverter is established to yield 110 V/60 Hz emergency source for critical appliances. The two power stages are implemented using an intelligent power module (IPM) with three legs. Good output ac sinusoidal voltage waveforms under unknown and nonlinear loads are obtained by the proposed model following the control scheme, with its tracking error regulation via proportional-plus-integral control and resonant control. Further improvement in waveform quality is achieved by robust control. Conversely, in charging mode, a buck switch-mode rectifier based charger is formed using the same IPM. The performance and rating analyses as well as the design for its power circuit components are derived in detail simultaneously. Satisfactory charging control performance and line drawn power quality are obtained.