SUSTAINING THE DISTRIBUTION GRID NETWORK RELIABILITY WITH DISTRIBUTED WIND TURBINE GENERATIONS

Abstract

Distributed generations are practically operated at the rated maximum power output. The locking off and on into the grid network of the intermittent power generating units is on availability basis. There are significant integration challenges posed by wind power generation due to its intermittency nature which seriously affect power grid stability and reliability issues related to grid power quality and voltage profile. Several reliability indices can be established to assess the distribution network reliability; they include ASAI, SAIFI, AENS and EENS. This study had the main purpose of optimizing placement and sizing of wind distributed generations through the application of the Particle Swarm Optimization algorithm to attain voltage profile improvement as well as network reliability enhancement by power loss reduction for radial distribution network - IEEE 33-bus system. The proposed PSO-based algorithm adequacy was investigated using MATLAB simulation on a radial distribution network - IEEE standard 33-bus test system, with a case study of Genetic Algorithm being used for validation of the solution techniques and model developed. The RDN test system is connected to a total of 3.32 MW and 2.71 MVAr; both real and reactive loads respectively. Modelling of the wind power generation considered for grid integration was variable reactive power model. A cut-off wind speed of ≥ 6 m/s on average was considered for power generation. Results from the analysis yield 0.2115 p.u of average active power produced by the wind turbine generator. 206.87 kW and 139.13 kVAr were the APL and RPL initial network configurations obtained respectively at 0.83pf when no DG was integrated. When wind DG is integrated at optimal placement and capacity, the reduction of the overall network power loss is 68.12% and 61.43% for real and reactive power loss accordingly. The voltage profile improved by 8.17% on installation of wind DG. The network ASAI reliability index value before wind DG integration was 0.99743 p.u. which improved by 1.81% after their installation. In general, network power losses are minimized besides acceptable voltage profile being maintained for a sustained distribution system reliability when several wind DGs are integrated.