The Grid Connected Distributed Power Generation Systems (Dpgs) Experiences More Sensitive Behaviour Against Small Variations Occurs In Grid Parameters. the Variations or Unbalance In Grid Parameters Are Mainly Due to the Presence of Voltage Sags, Frequency Variations, and Distorting Harmonics In the Grid. the Adverse Effect of Unbalanced Grid Conditions May Create the Failure In Synchronized Operation Between Dpgs and Its Connected Grid.In This Work to Provide Continuous Synchronization For Dpgs During Both Balanced and Unbalanced Condition of Grid, Two Novel Grid Synchronization Techniques Based on Phase Locked Loop (Pll) Studied Are (I) Modified Double Decoupled Synchronized Reference Frame Pll (Ii) Modified Double Second Order Generalize Integrator Pll.
The Main Aim of the Presented Modules Is to Provide Sequence Components of Grid Voltage. These Sequence Components Helps In Determining Magnitude and Phase Angle of Unbalanced Grid. the Presented Pll Configurations Are Worked Based on Synchronous Reference Frame Algorithms I.E. the Park’S Conversion Method Is Applied to Convert 3-Phase Abc Voltage Vector to Rotating D-Q Reference Frame Components. the Generated Positive Sequence D-Component Is Used to Determine Magnitude of Utility Voltage and the Positive Sequence Q-Component Is Used to Get Phase Angle of Grid Voltage Using Phase Locked Loop (Pll) Circuit. the Pll Circuit Also Maintains the Frequency and Phase Angle of Dpgs Same As the Determined New Phase Angle Value of G ...