Phase-locked loop control technology

In grid-connected PV system, need the phase and frequency of real-time detection of grid voltage to control grid-connected inverter, the output current and voltage in phase and frequency synchronization, synchronization phase-locked.

PLL is a key technology of photovoltaic grid-connected system, its precision directly affects the performance of parallel operation system. If the PLL circuit is not reliable, the inverter and grid work handover will produce circulation between the inverter and the grid, the impact on the equipment, shorten the service life of the equipment, serious when also will damage the equipment.

At present, the application of digital phase-locked loop based on DSP