Multiobjective optimization in combinatorial wind farms system integration and resistive SFCL using analytical hierarchy process

Abstract

This paper presents a positive approach for low voltage ride-through (LVRT) improvement of the permanent magnet synchronous generator (PMSG) based on a large wind power plant (WPP) of 50MW. The proposed method utilizes the conventional current control strategy to provide a reactive power requirement and retain the active power production during and after the fault for the grid codes compliance. Besides that, a resistive superconducting fault current limiter (RSFCL) as an additional self-healing support is applied outside the WPP to further increase the rated active power of the installation, thereby enhance the dc-link voltage smoothness, as well as the LVRT capability of the 50MW WPP. This is achieved by limiting the exceed fault current and diminishing the voltage dip level, leading to increase the voltage safety margin of the LVRT curve. Furthermore, the effect of the installed RSFCL on the extreme load reduction is effectively demonstrated. A large WPP has a complicated structure using several components, and the inclusion of RSFCL composes this layout more problematic for optimal performance of the system. Hence, the most-widely decision-making technique based on the analytic hierarchy process (AHP) is proposed for the optimal design of the combinatorial RSFCL and 50MW WPP to compute the three-dimensional alignment in Pareto front at the end of the optimization run. The numerical simulations verify effectiveness of the proposed approach, using the Pareto optimality concept.

A modified capacitive bridge-type fault current limiter (CBFCL) for LVRT performance enhancement of wind power plants

“…The DC reactor value used in the proposed CBFCL is smaller than the BFCL used in Firouzi and Gharehpetian, which results in considerable cost savings. The proposed CBFCL provides the reactive power to support the grid connecting point voltage by series capacitive compensation. This characteristic of the CBFCL fulfills the LVRT requirements of the WPP during and after fault period, which is the main advantage of the proposed CBFCL to the other types of FCLs …”

“…In other works, the application of the resistive‐type superconducting fault current limiter has been proposed for improving the LVRT capability of WPPs. In Salami and Firouzi, the conventional bridge‐type fault current limiter (BFCL) based on superconducting coil has been used for transient stability enhancement and SCC limitation of WPPs during fault.…”

“…Static synchronous compensator (STATCOM), 11,12 thyristor switch capacitor, 13 static var compensator, 14 have been used as shunt options. Dynamic voltage restorer, 15 series dynamic braking resistor (SDBR), 16 unified inter-phase power controller, 17 voltage booster scheme based on continuously variable series braking resistor, 18 gate-controlled series capacitor, 19 and fault current limiters (FCLs) [20][21][22][23][24][25][26][27] are series options. The pitch angle control is another solution for LVRT performance enhancement of SCIG-based WPPs, but its response is relatively slow.…”

“…Among these solutions, the application of FCLs was found to be effective for SCC limitation and LVRT performance enhancement of both variable speed [20][21][22][23] and fixed speed WTs. [24][25][26][27] Application of the FCLs for grid connection of WPPs allows equipment to remain in service, even if the fault current exceeds its rated peak and short time withstand current.…”

“…This characteristic of the CBFCL fulfills the LVRT requirements of the WPP during and after fault period, which is the main advantage of the proposed CBFCL to the other types of FCLs. [20][21][22][23][24][25][26][27] PSCAD/EMTDC software has been used to perform simulations. Also, a comparative study of the proposed CBFCL and the IBFCL is carried out.…”