Two switches based AC-link phase-shifter

Abstract

Static quadrature phase shifters controlled by pulse width modulation allow controlling the power flow in a transmission line by introducing a phase shift between sending and receiving voltage nodes. This work proposes a PWM quadrature phase shifter which uses only two driven switches which is advantage again current topologies that use six or four switches. As other AC-link converters, the PWM control is based on DC signals asynchronous from the grid, free of PLL and trigonometric calculations, this also makes frequency and phase perturbation don't affect the pulse width modulation as in the traditional PLL-synchronized SPWM, while the control can be accomplished with a low-cost micro controller, simulation and experimental result are shown to prove the principle of the proposition.