Title :
Fuzzy multi-objective technique integrated with differential evolution method to optimise power factor and total harmonic distortion
Author :
Darvishi, Atena ; Alimardani, A. ; Hosseinian, Seyed Hossein
Author_Institution :
Dept. of Electr. Eng., Amirkabir Univ. of Technol., Tehran, Iran
fDate :
9/1/2011 12:00:00 AM
Abstract :
The main aim of active-filter-based power-quality improvement schemes is to reduce the total harmonic distortion (THD) and improve power factor (PF). According to standards, selective harmonic distortion (SHD) should be controlled too. Non-sinusoidal current owing to non-linear loads causes a non-sinusoidal voltage. Under such conditions, any attempt to make the power factor unity by usual methods will cause a non-sinusoidal current, which increases the THD. Also, attempt for harmonic-free current may not conclude unity power factor because of harmonics present in the voltage. Thus, there is a tradeoff between reduction of THD and improvement in power factor. One of the solutions to this tradeoff is to optimise PF while keeping THD and SHD into their specified limits. Differential evolution (DE) is introduced in this study and used for this optimisation problem, and the results are compared with four types of particle swarm optimisation (PSO), including conventional PSO, linearly decreasing inertia PSO, Type 1 PSO, constant inertia PSO and with the traditional optimisation method. It is seen that DE algorithm converges to a better result much faster than the other algorithms. Furthermore, using fuzzy strategy a multi-objective optimisation is proposed to optimise PF and THD simultaneously while keeping SHD in its limit. It is observed that using these optimisation methods, PF and THD are more improved.
Keywords :
active filters; fuzzy set theory; harmonic distortion; particle swarm optimisation; power factor; power harmonic filters; power supply quality; DE algorithm; PSO; SHD; THD; active-filter-based power-quality improvement schemes; differential evolution method; fuzzy multiobjective technique; harmonic-free current; particle swarm optimisation; power factor optimisation; selective harmonic distortion; total harmonic distortion;
Journal_Title :
Generation, Transmission & Distribution, IET
DOI :
10.1049/iet-gtd.2010.0712