Control of grid-side rectifiers for locomotive applications must cope with parametric fluctuations, dramatic change of operation condition such as grid voltage, as well as malfunctions and faults of switching devices and sensors. With the introduction of vehicular electronic transformers, fragile power-electronics is directly connected to the grid, even though with a filtering coil. This makes the afore mentioned problems much more serious. Thus the robustness and fault tolerance become more and more important for this kind of devices. Robust \({H_\infty }\) loop shaping controller is designed for current loop control of single phase PWM rectifier. The main objective is to study the performance and robustness against parametric uncertainties based on \(\nu \) gap metric.