Control of Power Electronic Converters
Technical Dialogue Session
PLL, phase locked loop, DSP, active rectifier
The performance of digitally controlled grid-connected power converters leverages the synchronization strategies. Single-phase phase locked loops (PLL) with a second-order generalized integrator (SOGI) as quadrature signal generation subsystem provide proper grid synchronization in the case of harmonically distorted grid voltage. The SOGI-PLL transient performance can be improved by replacing the PLL by a frequency locked loop (FLL). However, compared with SOGI-PLLs, SOGI-FLLs perform poorly in steady-state. This work proposes, therefore, including a secondary control path (SCP) to improve the dynamics of SOGI-PLLs while maintaining the steady-state performance. Simulation and experimental results validating the proposal are provided.