Four-quadrant bidirectional AC-DC converter for plug-in electric vehicle charger with grid reactive power support

The unidirectional AC-DC converters that are used in Plug-in Electric Vehicles (PEVs) for charging the battery pack can be redesigned for bi-directional operation. This enables both active power support and reactive power compensation to the grid in the reverse direction i.e. V2G mode. Presently available vehicle to grid (V2G) support systems are based on simple phase locked loop (PLL) in which the input phase angle detection takes longer time, in addition to undesirable steady-state oscillations. This paper presents a modified controller that uses second order generalized integrator (SOGI) based phase locked loop (PLL) for tracking the line voltage phase angle and generating the reference phase signal for the charger current of AC-DC converters in PEVs. The converter operates in four quadrants of the active-reactive (PQ) power plane with eight different operating modes, depending on the specified PQ demand inputs in a smart grid environment. The proposed converter system is simulated in MATLAB-Simulink environment and the simulation results prove the stable dynamic response of the proposed controller and assure the required reactive power support functionality of Plug-in Electric Vehicle chargers for smart grid applications.