Control Method of Magnetic Flux Source Type Grid Forming Based on DC Voltage Synchronization
The existing grid following/grid forming control methods are difficult to achieve consistent and stable operation in both strong and weak electrical networks.For this purpose,a magnetic flux source type grid forming control method based on DC voltage synchronization was proposed.Based on the DC voltage synchronization control loop and the AC voltage amplitude control loop,the three-phase magnetic flux reference value of the grid connected bus was obtained.Through pulse width modulation control,the actual magnetic flux was tracked against the reference magnetic flux,enabling the inverter to have magnetic flux source characteristics.Then,the boundedness of magnetic flux tracking error was derived,stability analysis of magnetic flux synchronization control was conducted,and large disturbance stability testing analysis was carried out.The results show that the magnetic flux source type grid inverter has better short-circuit recovery ability and synchronization stability compared to the traditional grid following and grid forming inverters,and can be compatible with strong and weak AC power grids for stable operation.
flux linkage synchronizationgrid-forming controlDC voltage synchronizationpulse width modulationlarge disturbance stability