IET Generation, Transmission & Distribution Research Article
Modified group search optimisation-based comparative performance evaluation of thyristor controlled series capacitor-based fractional order damping controllers to improve load frequency control performance in restructured environment
ISSN 1751-8687 Received on 22nd December 2016 Revised 19th May 2017 Accepted on 24th July 2017 doi: 10.1049/iet-gtd.2016.2094 www.ietdl.org
Q1
Javad Morsali1 , Kazem Zare1, Mehrdad Tarafdar Hagh1,2 1Faculty
of Electrical & Computer Engineering, University of Tabriz, Tabriz, Iran Faculty, Near East University, 99138 Nicosia, North Cyprus, Mersin 10, Turkey E-mail:
[email protected]
2Engineering
Abstract: This study compares fractional order phase lead-lag controller, fractional order proportional-integral-derivative (FOPID), and tilt-integral-derivative controllers as thyristor controlled series capacitor (TCSC)-based damping controller to improve load frequency control (LFC) performance in a restructured power system. To prepare an efficient ancillary service, a precise formulation for participation of TCSC in tie-line power flow exchange is presented which is compared with the earlier Taylor-based approximated model. The controller parameters are adjusted by employing different evolutionary algorithms. To obtain realistic results under a competitive environment, a diverse-GENCOs multi-DISCOs power system with the generation rate constraint and governor dead-band effects, communication time delay, bilateral contracts, and pool-co transactions is taken into account. Non-linear time-domain simulations demonstrate that the FOPID-based TCSC damping controller in coordination with an integral-type simple LFC can most effectively suppress the area frequency and tie-line power oscillations. Further investigations are performed for uncontracted higher order step and random load demands treated as contract violation scenarios to confirm the superiority of the proposed fractional order controllers-based TCSC–LFC over the Taylor-based TCSC– LFC. The sensitivity analysis is done for a wide range of loading condition and system parameters to compare the robustness of the considered controllers.
Nomenclature ACE AGC cpf DISCOi DPM epfi FACTS FOMCON FOC FOPID FOPLC GCSC GDB GENCOi GRC IOC IOPID IPSO ISE ITAE ITSE LFC MGSO RTU SSSC
area control error automatic generation control contract participation factor ith distribution company DISCO participation matrix economic participation factor of GENCOi flexible alternating current transmission system fractional order modelling and control fractional order controller fractional order proportional-integral derivative fractional order phase lead-lag controller gate-controlled series capacitor governor dead-band ith generation company generation rate constraint integer order controller integer order proportional integral derivative improved particle swarm optimisation integral of squared error integral of time multiplied absolute error integral of time multiplied squared error load frequency control modified group search optimisation remote terminal unit static synchronous series compensator
IET Gener. Transm. Distrib. © The Institution of Engineering and Technology 2017
TCPS TCSC TID tilt-integral derivativea12 Bg Bi Cg Dik Δfi Kps1, Kps2 Kr KP, KT, KI, KD KI1, KI2 KTCSC, TTCSC KC MP N N1, N2 Pri 0 ΔP12 ΔPdi ΔPTCSC
thyristor controlled phase shifter thyristor controlled series capacitor ratio of areas’ power ratings time constant of the valve positioned frequency bias coefficient in area i (i = 1, 2) gas turbine valve positioner head direction of ith member at kth iteration frequency deviation in area i (i = 1, 2) power system gains steam turbine reheat constant proportional, tilt, integral, and derivative gains integral gains of LFC loop gain and time constant of TCSC controller series compensation ratio maximum peak order of Oustaloup's approximation Fourier coefficients of GDB transfer function rated power of area i (i = 1, 2) tie-line actual power exchange without TCSC uncontracted load disturbance in area i (i = 1, 2) TCSC contribution in tie-line power exchange 1
actual ΔP12 error ΔP12 ΔPth
ΔPhyd ΔPg ΔPgki ΔPuck ΔPmi ΔPLj scheduled ΔP12 Rth, Rhyd, Rg Tsg Tt Tw Tr Tps1, Tps2 Tgh Tcd Tf Tcr Trs Tsim Ts TP T1, T3 T12 |Vi|
