A Novel PLL for Auxiliary Supply System in Railway Vehicles

Synchronous rotating frame phase-locked loop(SRF PLL) can make the slave auxiliary inverter track the phase angle and amplitude of the master auxiliary inverter in the high-power auxiliary power supply system of railway vehicles, so as to complete the parallel power supply of the auxiliary inverter and improve the reliability of the auxiliary power supply system. However, the phase angle detected by SRFPLL will oscillate when the amplitude of three-phase grid voltage is unbalanced or distorted. In order to solve this problem, this paper proposes a new phase-locked loop structure based on the characteristics of double order generalized integral phase-locked loop (DSOGI PLL) and coordinate rotation digital computer (CORDIC), and model and simulate by using MATLAB. Finally, the simulation waveforms of various PLLs are compared, and it is verified that the novel PLL architecture can get high accurate phase angle more quickly when the three-phase power grid is abnormal.