Maintaining the Power Grid Distribution Network Reliability with Wind Turbine Distributed Generations

Abstract

Intermittent power generating units lock on and off into the grid on availability basis. Practically, the operation of distributed generations is always done at the maximum rated power output. Wind power generation poses significant integration challenges due to its nature of intermittency that leads to serious issues of power grid reliability and stability with regards to voltage profile which affect quality of the grid power. Network reliability can be maintained by observing several reliability indices in existence including SAIDI, EENS, SAIFI, AENS and ASAI The purpose of the study was to optimize capacity and siting of wind distributed generations using Particle Swarm Optimization algorithm for improved system reliability and voltage profile by minimizing power losses in an electrical distribution network. Evolutionary optimization methods yield to results that suffer from premature convergence that require enhancement and modifications. MATLAB simulation was used to investigate the adequacy of the proposed PSO-based algorithm on IEEE standard 33-bus radial distribution network test system, and Genetic Algorithm case study was used to validate the developed model and solution techniques. The total reactive and active loads connected to the RDN test system are 2.72MVAr and 3.31MW respectively. The wind power generation was modelled as variable reactive power model for grid integration. The cut-off wind speed for power generation on average is considered to be <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\geq$</tex> 6 m/s. Calculations in this analysis yield average real power generated by wind turbine generator as 0.2115 p.u The initial network configuration, RPL and APL obtained are 139.12kVAr and 206.86kW respectively without DG at 0.83pf. On integration of wind DG of optimal size and location, the overall line power loss reduces by 67.13% and 60.44% for active and reactive power losses respectively. The wind DG installation improves the voltage profile by 8.16%. The value of ASAI reliability index before integration of the wind DGs was 0.99744 p.u. and after their installation it improves by 1.80%. In conclusion, there is minimized power losses while maintaining acceptable voltage profile in a distribution network for sustained reliability when more wind DGs are installed at optimal sites and capacities using the proposed method.