Indian Journal of Science and Technology
Year: 2013, Volume: 6, Issue: 7, Pages: 1-13
Hamidreza Mahdian1∗ , Mohamadreza Hashemi2 and Ali Asghar Ghadimi3
1 Department of Electrical Engineering, [email protected]
2 Department of Electrical Engineering, [email protected]
3 Department of Electrical Engineering, [email protected]
*Author For Correspondence
Department of Electrical Engineering,
Phase-Locked Loop (PLL) Structures have many applications in power system engineering. When required the synchronous performance of Voltage Sourced Converter (VSC) with Grid, such as wind power generation system, active filters, HVDC transmission lines and FACTS devices, the most common method for accurate estimation of frequency of network, is to use a PLL. However, problems such as grid disturbances due to noise, voltage unbalances, lack of coordination, changes in grid frequency and harmonics can produce a frequency disturbance, twice the grid frequency and disturbed PLL and also the control system connected to it. In this paper, common structures of PLL is introduced. After that, unbalance and disturbance in the three phase input of PLL is studied. Then for idea and invention in PLL, a new control method based on predictive control technique is used in the control strategy of converter. Furthermore, the use of type III controller in PLL to ensure optimal performance in various conditions is proposed in this paper. How to set the parameters of the proposed controller is described by the Bode stability criterion. Conducting simulations to evaluate the performance of the proposed method is done in PSIM software. According to the proposed method and the result observed, the double frequency disturbance term is weakened and also the transient state is improved
Keywords: Phase-Locked Loop (PLL), Voltage-Sourced Converters (VSC), Synchronization, Current Control, Unbalanced Voltage.
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