Quasi-oppositional Harmony Search Research Articles

Load frequency stabilization of stand‐alone hybrid distributed generation system using QOHS algorithm

AbstractThe proposed work studies the frequency stability of the identified hybrid power network (HPS) model with the integration of RESs and ESDs. The research work depicted here includes load frequency issue pertaining to isolated mode of operations with uncertainties in power oscillations of wind and solar energy. The studied HPS model is constitute of three wind turbine generators, two solar thermal generators, three diesel engine generators, an aqua electrolyzer and two fuel‐cells as generating units while battery energy storage system, flywheel energy storage system and ultra‐capacitor as back‐up energy sources. A centralized control scheme using PID controller is employed for the controller design problem and its parameters are tuned by a nature inspired Quasi‐oppositional Harmony Search (QOHS) algorithm. The three scenarios as step change, step change with stochastic effects and firm model of wind velocity, solar radiation and load demand are studied for the load frequency control dynamic performance. The execution of suggested QOHS based PID controller is contrasted with the studied optimization techniques. It may be inferred that the RESs and ESDs feeding isolated loads are properly operated to attain the coveted level of system frequency by using the QOHS technique.

Load Frequency Control of Distributed Generators Assisted Hybrid Power System Using QOHSA Tuned Model Predictive Control

One of the challenging issues in a hybrid power system (HPS) is to provide a stable power supply with minimum frequency deviation, which can be accomplished by ensuring a coordinated operation among intermittent type distributed generators (DGs). In this study, the coordinated operation of a tidal turbine generator (TTG) (an emerging and less explored DG), diesel engine generator (DEG) and plug-in hybrid electric vehicles (PHEVs) based an autonomous HPS (a less explored HPS of this kind) for load frequency control (LFC) is investigated. The coordinated operation of different control loops such as the blade pitch control loop of TTG, supplementary control loop of DEG, and power control loop of PHEVs are realized through the maiden application of the proposed quasi-oppositional harmony search algorithm (QOHSA) based model predictive control (MPC) strategy. To establish the superiority of the proposed QOHSA tuned MPC method in mitigating frequency deviation following disturbance, its performance is compared with that of the coordinated performance obtained using QOHSA tuned conventional controllers and other existing optimization algorithms. The results conclude that the suggested method can significantly reduce frequency fluctuation under different load disturbances. The proposed method can handle different variances of the disturbance signals or noise entering the system as well as the model mismatch.

An Improved Hybrid Micro-Grid Load Frequency Control Scheme for an Autonomous System

This paper presents an improved hybrid micro-grid load frequency control scheme for an autonomous system. The micro-grid system comprises of renewable and non-renewable energy-based Power Generating Units (PGU) which consist of Solar Photovoltaic, WT Generator, Solar Thermal Power Generator, Diesel Engine Generator, Fuel Cell (FC) with Aqua Electrolizer (AE). However, power produce from renewable sources in microgrid are intermittent in supply, hence make it difficult to maintain power balance between generated power and demand. Therefore, Battery energy storage system, ultra-capacitor and flywheel energy storage systems make up the energy storage units. These separate units are selected and combined to form two different scenarios in this study. This approach mitigates frequency fluctuations during disturbances (sudden load changes) by ensuring balance between the generated power and demand. For each scenario, Moth flame optimization algorithm optimized Proportional-Integral controllers were utilized to control the micro-grid (to minimize fluctuations from the output power of the non-dispatchable sources and from sudden load change). The results of the developed scheme were compared with that of Quasi-Oppositional Harmony Search Algorithm for overshoot and settling time of the frequency deviation. From the results obtained, the proposed scheme outperformed that of the quasi-oppositional harmony search algorithm optimized controller by an average percentage improvement of 35.95% and 28.76% in the case of overshoot and settling time when the system step input was suddenly increased. All modelling analysis were carried out in MATLAB R2019b environment. Keywords—Frequency Deviation, Micro-grid, Moth flame optimization algorithm, Quasi-Oppositional Harmony Search Algorithm.

Design and Implementation of Frequency Controller for Wind Energy-Based Hybrid Power System Using Quasi-Oppositional Harmonic Search Algorithm

An innovative union of fuzzy controller and proportional-integral-derivative (PID) controller under the environment of fractional order (FO) calculus is described in the present study for an isolated hybrid power system (IHPS) in the context of load frequency control. The proposed controller is designated as FO-fuzzy PID (FO-F-PID) controller. The undertaken model of IHPS presented here involves different independent power-producing units, a wind energy-based generator, a diesel engine-based generator and a device for energy storage (such as a superconducting magnetic energy storage system). The selection of the system and controller gains was achieved through a unique quasi-oppositional harmony search (QOHS) algorithm. The QOHS algorithm is based on the basic harmony search (HS) algorithm, in which the combined concept of quasi-opposition initialization and HS algorithm fastens the profile of convergence for the algorithm. The competency and potency of the intended FO-F-PID controller were verified by comparing its performance with three different controllers (integer-order (IO)-fuzzy-PID (IO-F-PID) controller, FO-PID and IO-PID controller) in terms of deviation in frequency and power under distinct perturbations in load demand conditions. The obtained simulation results validate the cutting-edge functioning of the projected FO-F-PID controller over the IO-F-PID, FO-PID and IO-PID controllers under non-linear and linear functioning conditions. In addition, the intended FO-F-PID controller, considered a hybrid model, proved to be more robust against the mismatches in loading and the non-linearity in the form of rate constraint under the deviation in frequency and power front.

Optimal load frequency control in deloaded tidal power generation plant‐based interconnected hybrid power system

In recent years, power utilities have witnessed increase in penetration of tidal power generation plant (TPGP) into the power system network and, hence, it may collaborate with conventional units in frequency regulation process to ensure power system stability. Therefore, this study presents a method to monitor the participation of TPGP in load frequency control mechanisms in the presence of conventional unit such as diesel power generation plant. The participation of TPGP is showcased based on primary frequency control topologies such as by producing additional inertia, additional damping along with the concept of deloading operation. These approaches are realised by employing conventional controllers to obtain required power (corresponding to different loading conditions) from TPGP by manipulating the kinetic energy of the rotating mass of tidal turbine blades. For better performance and improved stability of the system, the controller parameters are optimised using quasi-oppositional harmony search algorithm (QOHSA). The effectiveness of QOHSA is proved by comparing the results obtained by it to those yielded by employing other existing state-of-the-art optimisation methods. The prospective analysis is validated in single-area and two-area hybrid power system models through MATLAB simulation studies.

Frequency stabilization of isolated and grid connected hybrid power system models

Abstract This paper investigates the load frequency control (LFC) of two different configurations of power system model. The first one is worked as an isolated hybrid power system (HPS) (IHPS) while the second one is a grid tied HPS (GHPS). In IHPS, the power generating units are diesel engine generator (DEG), wind turbine generator (WTG) and solar thermal power generation (STPG). It is considered in such a way that the generation persists throughout the day with uninterrupted power supply. The energy storage device used in this work is superconducting magnetic energy storage (SMES). The three scenarios considered in isolated mode are (a) HPS with one DEG, one WTG and one STPG, (b) HPS with one DEG and one STPG and (c) HPS with one DEG and one WTG. As concerned to GHPS, a combination of WTG and steam thermal power plant is considered. A conventional proportional-integral-derivative (PID) controller has been used as supplementary control mechanism. The PID controller gains and the tunable parameters of the SMES are tuned by the use of quasi-oppositional harmony search (QOHS) algorithm. Initially, integral of time absolute error based objective function is minimized and, subsequently, three performance indices such as integral of absolute error, integral of square error and integral of time square error are calculated to test the designed efficiency of the proposed QOHS based PID controller. The transient responses of systems pertaining to step and random changes in the load demand are analyzed. The simulated results obtained by the QOHS algorithm reveals that it may be imposed to boost LFC performance of the power system.

Dynamic stability enhancement of TCSC‐based tidal power generation using quasi‐oppositional harmony search algorithm

This study presents the dynamic and steady state stability improvement of a tidal power generation system (TPGS) assisted power system model (i.e. single machine infinite bus (SMIB) system) using a thyristor controlled series capacitor (TCSC). To achieve this objective, the TCSC used in the studied model is optimally designed using quasi-oppositional harmony search algorithm (QOHSA). The complete dynamic equation of the studied power system is realised based on d–q-axis decomposition. Eigenvalue analysis is performed using the frequency-domain approach to study the steady-state stability while the time-domain-based simulation is carried out to determine the dynamic stability of the studied system. To corroborate the effectiveness of QOHSA, results yielded by this algorithm are compared with those obtained using particle swarm optimisation technique. It may be inferred from the results obtained in this study that the QOHSA tuned TCSC outperforms the other in improving the overall stability of the TPGS-based SMIB system following disturbance. Furthermore, a similar analysis is extended to the TPGS-based multi-machine power system model to validate the efficiency of QOHSA in optimal designing of TCSC for dynamic stability improvement.

Quasi‐oppositional harmony search algorithm based optimal dynamic load frequency control of a hybrid tidal–diesel power generation system

In recent years, high penetration of distributed generations based on wind energy, solar energy and so on in the existing power system network has been noticed. However, due to their stochastic behaviour, operations under autonomous mode as well as in grid-connected mode are not an easy task. This has forced the power utilities to re-define frequency regulation criteria to enhance the overall system stability and reliability. In line with the same, dynamic performance analysis of load frequency control (LFC) of an autonomous hybrid power system model (HPSM) consisting of tidal power plant (TPP) and diesel power plant is explored in this study. A concept of deloaded TPP is adopted in the studied HPSM to utilise the available reserve power for the frequency support. Apart from this, the studied model also incorporates frequency regulation through inertia and damping control and supplementary control strategies. These control strategies are realised through conventional controllers whose gain values are optimised using quasi-oppositional harmony search algorithm (QOHSA) for the optimal dynamic performance of LFC. The efficacy of the proposed QOHSA is corroborated by comparing the results with those yielded by few other existing state-of-the-art algorithms.

Fractional order fuzzy PID controller for wind energy‐based hybrid power system using quasi‐oppositional harmony search algorithm

In this study, a novel fuzzy logic control scheme is investigated for the frequency and power control of an isolated hybrid power system (HPS) (IHPS) and HPS-based two-area power system. The studied IHPS comprises of various autonomous generation systems such as wind energy, diesel engine generator and an energy storage device (i.e. capacitor energy storage device). A novel fractional order (FO) fuzzy proportional-integral-derivative (PID) (FO-F-PID) controller scheme is deployed and the various tunable parameters of the studied model are tuned by quasi-oppositional harmony search (HS) (QOHS) algorithm for improved performance. The QOHS algorithm (based on standard HS algorithm) accelerates the convergence speed by combining the concept of quasi-opposition in the basic HS framework. This FO-F-PID controller shows better performance over the integer order-PID and F-PID controller in both linear and non-linear operating regimes. The proposed FO-F-PID controller also shows stronger robustness properties against loading mismatch and different rate constraint non-linarites than other controller structures.

TCSC based automatic generation control of deregulated power system using quasi-oppositional harmony search algorithm

In present aspect, automatic generation control (AGC) of deregulated power system with thyristor controlled series compensator (TCSC) device is investigated. The objective is to discuss bilateral power transaction issue with the TCSC effect. A deregulated two-area power system model having two thermal units in each control area is considered for this act. A quasi-oppositional harmony search (QOHS) algorithm is being applied for the constrained optimization problem. Three cases, commonly studied in deregulation, are discussed for the effectiveness of the proposed technique. Further, sensitivity analysis is studied by varying the test system parameters up to ±25% from their rated values. The obtained simulation plots are analytically discussed with the calculation of oscillatory modes, transient details and the studied performance indices. Sugeno fuzzy logic control technique is also investigated to the studied test system. The simulation results show that the proposed QOHS based TCSC controller is quite effective in deregulated environment.

A novel scaling factor based fuzzy logic controller for frequency control of an isolated hybrid power system

Highly intermittent power, generated by wind energy in an isolated hybrid power system (IHPS), results in severe frequency and power fluctuation. The aim of this paper is to carry out a comparative study of scaling factor (SF) based fuzzy logic controller (FLC) (SF-FLC), SF-FLC with proportional-integral (PI) (SF-FLC-PI) controller, SF-FLC with proportional-derivative (PD) (SF-FLC-PD) controller and SF-FLC with proportional-integral-derivative (PID) (SF-FLC-PID) controller for deviation in frequency and power of an IHPS model. The undertaken model of IHPS for this study embraces a diesel engine generator, a wind turbine generator and an energy storage device (for instance, capacitive energy storage). Optimal tuning of the different tunable parameters considered for suppressing the deviation in frequency and power of IHPS model owing to alteration in load demand has been carried out by quasi-oppositional harmony search (QOHS) algorithm. The obtained results demonstrate minimum deviation in frequency and power may be realized by practicing the proposed SF-FLC-PID controller for the considered IHPS model. Robustness and non-linearity investigation have been also executed for the proposed SF-FLC-PID controller based configuration of the studied IHPS model. It is revealed that the proposed SF-FLC-PID controller is very much robust in nature and takes care of non-linearity very well while QOHS algorithm is adopted.

A Frequency Control Approach for Hybrid Power System Using Multi-Objective Optimization

A hybrid power system uses many wind turbine generators (WTG) and solar photovoltaics (PV) in isolated small areas. However, the output power of these renewable sources is not constant and can diverge quickly, which has a serious effect on system frequency and the continuity of demand supply. In order to solve this problem, this paper presents a new frequency control scheme for a hybrid power system to ensure supplying a high-quality power in isolated areas. The proposed power system consists of a WTG, PV, aqua-electrolyzer (AE), fuel cell (FC), battery energy storage system (BESS), flywheel (FW) and diesel engine generator (DEG). Furthermore, plug-in hybrid electric vehicles (EVs) are implemented at the customer side. A full-order observer is utilized to estimate the supply error. Then, the estimated supply error is considered in a frequency domain. The high-frequency component is reduced by BESS and FW; while the low-frequency component of supply error is mitigated using FC, EV and DEG. Two PI controllers are implemented in the proposed system to control the system frequency and reduce the supply error. The epsilon multi-objective genetic algorithm ( ε -MOGA) is applied to optimize the controllers’ parameters. The performance of the proposed control scheme is compared with that of recent well-established techniques, such as a PID controller tuned by the quasi-oppositional harmony search algorithm (QOHSA). The effectiveness and robustness of the hybrid power system are investigated under various operating conditions.

Study of differential search algorithm based automatic generation control of an interconnected thermal-thermal system with governor dead-band

An attempt has been made to the effective application of a recently introduced, powerful optimization technique called differential search algorithm (DSA), for the first time to solve load frequency control (LFC) problem in power system. In this paper, initially, DSA optimized classical PI/PIDF controller is implemented to an identical two-area thermal-thermal power system and then the study is extended to two more realistic power systems which are widely used in the literature. To assess the usefulness of DSA, three enhanced competitive algorithms namely comprehensive learning particle swarm optimization (CLPSO), ensemble of mutation and crossover strategies and parameters in differential evolution (EPSDE), and success history based DE (SHADE) are studied in this paper. Moreover, the superiority of proposed DSA optimized PI/PID/PIDF controller is validated by an extensive comparative analysis with some recently published meta-heuristic algorithms such as firefly algorithm (FA), bacteria foraging optimization algorithm (BFOA), genetic algorithm (GA), craziness based particle swarm optimization (CRPSO), differential evolution (DE), teaching-learning based optimization (TLBO), particle swarm optimization (PSO), and quasi-oppositional harmony search algorithm (QOHSA). A case of robustness and sensitivity analysis has been performed for the concerned test system under parametric uncertainty and random load perturbation. Furthermore, to demonstrate the efficacy of proposed DSA, the system nonlinearities like reheater of the steam turbine and governor dead band are included in the system modeling. The extensive results presented in this article demonstrate that proposed DSA can effectively improve system dynamics and may be applied to real-time LFC problem.

Integrated frequency and power control of an isolated hybrid power system considering scaling factor based fuzzy classical controller

Abstract This paper describes an application of quasi-oppositional harmony search (QOHS) algorithm to design the scaling factor (SF) based fuzzy-classical controller (such as PI/PD/PID) for frequency and power control of an isolated hybrid power system (IHPS). The considered IHPS model is comprised of a wind turbine generator, a diesel engine generator and an energy storage device (such as superconducting magnetic energy storage (SMES), in this case). Traditionally, SF, membership functions and control rules are obtained in fuzzy logic controllers (FLCs) by trial and error method or are obtained based on the experiences of the designers or are optimized by some traditional optimization techniques with some extra computational cost. To overcome all these problems of FLCs, classical controllers have been integrated in this paper with the FLC. QOHS algorithm is applied to simultaneously tune the SFs (the only tunable parameter of FLC), the gains of the classical controllers and the tunable parameters of the SMES device to minimize frequency and power deviations of the studied IHPS system against various load demand and wind change. Different considered controller configurations of the IHPS are SF based FLC (termed as Fuzzy-only), SF based FLC with proportional-integral (PI) (named as Fuzzy-PI) controller, SF based FLC with proportional-derivative (PD) (abbreviated as Fuzzy-PD) controller and SF based FLC with proportional-integral-derivative (PID) (designated as Fuzzy-PID) controller. Simulation results, explicitly, show that the performance of the Fuzzy-PID controller based IHPS is superior to Fuzzy-only, Fuzzy-PI and Fuzzy-PD controller based IHPS configuration in terms of overshoot, settling time and the proposed Fuzzy-PID controller is robust against various wide range of load changes.

Automatic Generation Control of Hydropower Systems Using a Novel Quasi-oppositional Harmony Search Algorithm

This article visualizes the behavior of a hydropower system in view of its automatic generation control through the adoption of a novel quasi-oppositional harmony search algorithm. The improvements in automatic generation control performance in reference to the proposed quasi-oppositional harmony search, as studied in a single- and two-area hydro–hydropower system models, are presented here. Both the qualitative and the quantitative aspects of the proposed algorithm are investigated by comparing its optimization performance with two powerful tuning methods (internal model control and maximum peak resonance specification) as reported in recent literature. Further, the robustness analysis of the single-area test system is carried out by changing the time constant of the hydro-turbine in the range of ±50%. For the two-area test system, a comparative dynamic performance analysis is also carried out by applying step load perturbation at unequal time intervals in both areas. It is established from the obtained simulation results that the proposed quasi-oppositional harmony search improves the overall system performance and may be adopted as a constrained optimization problem for the hydropower system.

Design and analysis of multi-source multi-area deregulated power system for automatic generation control using quasi-oppositional harmony search algorithm

The present article focuses on the study of automatic generation control (AGC) of a realistic power system having a distinct combination of multi-area multi-source generating units in each control area under deregulated framework. An attempt is made in this paper to integrate reheat thermal, hydro and gas generating unit in a single control area and, then, extended this combination to five control areas. In this work, six reheat thermal, six hydro and three gas generating units are taken into account for the modeling of five-area power system. Some important physical constraints like time delay, governor dead band and generation rate constraint are imposed in the power system dynamics to get an accurate perception of the deregulated AGC subject. The highlighting features of the present work are to model, simulate, optimize and co-relate their inter-related dynamic performances for the purpose of AGC study. For such a complex AGC model, the vital role of the proposed quasi-oppositional harmony search (QOHS) algorithm, as an optimizing tool, is signified while solving the AGC problem in deregulated regime. The simplicity of the structure and acceptability of the responses of the well-known proportional–integral–derivative controller, inherently, enforces to employ in this work. The three classes of extensive deregulated cases (in the presence of load following and physical constraints) are demonstrated by examining the closed loop performance of the studied model. The simulation results show that the designed power system model may be a feasible one and the proposed QOHS algorithm may be a promising optimization technique under these circumstances.

Load frequency control of an autonomous hybrid power system by quasi-oppositional harmony search algorithm

Abstract This paper deals with a novel quasi-oppositional harmony search algorithm (QOHSA) based design of load frequency controller for an autonomous hybrid power system model (HPSM) consisting of multiple power generating units and energy storage units. QOHSA is a novel improved version of music inspired harmony search algorithm for obtaining the best solution vectors and faster convergence rate. In this paper, the efficacy of the proposed QOHSA is adjudged for optimized load frequency control (LFC) of an autonomous HPSM. The studied HPSM consists of renewable/non-renewable energy based generating units such as wind turbine generator, solar photovoltaic, solar thermal power generator, diesel engine generator, fuel cell with aqua-electrolyzer while energy storage units consists of battery energy storage system, flywheel energy storage system and ultra-capacitor. Gains of the conventional controllers such as integral (I) controller, proportional–integral (PI) controller and proportional–integral–derivative (PID) controller (installed as frequency controller one at a time in the proposed HPSM) is optimized using QOHSA to mitigate any frequency deviation owing to sudden generation/load change. In order to corroborate the efficacy of QOHSA, performance of QOHSA to design optimal LFC is compared with that of other well-established technique such as teaching learning based optimization algorithm (TLBOA). The comparative performances of the HPSM under the action of QOHSA/TLBOA based optimized conventional controllers (I or PI or PID) are investigated and compared in the present work. It is found that the QOHSA tuned frequency controllers improves the overall dynamic response in terms of settling time, overshoot and undershoot in the profile of frequency deviation and power deviation of the studied HPSM.

Automatic generation control of multi‐unit multi‐area deregulated power system using a novel quasi‐oppositional harmony search algorithm

This initiative work deals with the automatic generation control (AGC) of multi-unit multi-area power system in the prospective of deregulated power environment owing to load following issues. In present outlook, a deregulated four-area power system having eight generation companies and eight distribution companies is treated as a plant model. The concerned objective is to intensify the bilateral behaviour and investigate the system AGC performance. In the state of deregulation, the influence of a novel quasi-oppositional harmony search (QOHS) algorithm based Sugeno fuzzy-logic (SFL) technique is proposed as an AGC optimisation task by showing its consequences on bilateral policy/dynamics. In the entire work, the proposed QOHS based SFL technique is incorporated for the tuning of on-line, off-nominal controller gains. The salient advantage of this control strategy is to provide good dynamic responses over a wide range of system parametric variations. The observations are based on the three deregulated cases which, generally, takes place in deregulated power market. The presented simulation results show that the proposed QOHS based SFL is a promising optimisation technique in the field of deregulated AGC study.

Frequency stabilisation of a hybrid two‐area power system by a novel quasi‐oppositional harmony search algorithm

Modelling, simulation and performance analysis of a two-area thermal-hybrid distributed generation (HDG) power system having different sources of power generation has been carried out in this study. The thermal power plant is consisting of re-heat type thermal system, whereas the HDG system includes the combination of wind turbine generator and diesel generator. In the studied model, superconducting magnetic energy storage (SMES) device is considered in both the areas. Additionally, a flexible ac transmission system (FACTS) device such as static synchronous series compensator (SSSC) is also considered in the tie-line. The different tunable parameters of the proportional-integral-derivative (PID) controllers, SMES and SSSC are optimised using a novel quasi-oppositional harmony search (QOHS) algorithm. Optimisation performance of the novel QOHS algorithm is established while comparing its performance with binary coded genetic algorithm. From the simulation work it is observed that with the inclusion of SMES in both the areas, the system performances toward the achievement of minimal frequency and tie-line power oscillations are promising under different types of input loading perturbations. It is further revealed from the simulation results that the installation of an expensive FACTS device such as SSSC does not yield any significant improvement to the system performance.

Quasi oppositional harmony search algorithm based controller tuning for load frequency control of multi-source multi-area power system

Abstract This paper deals with the load frequency control (LFC) study of single-area and interconnected two-area power system having diversified power sources. The two areas considered in the present study are identical. Each area is having thermal, hydro and gas based power plants. Split-shaft model of gas turbine is used in the present work as one of the diversified generating unit for the purpose of LFC study. Optimal gains of the classical controllers (like integral controller, proportional–integral controller and proportional–integral–derivative (PID) controller, one installed at a time in the studied models) are obtained by using a novel music-inspired metaheuristic harmony search algorithm (HSA) which incorporates quasi opposition based learning technique for memory initialization and also for generation jumping. Single-area power system with diverse power sources is considered and its optimal transient performances are obtained and compared for step load perturbation. The same approach is further extended to two-area interconnected power system consisting of diverse power sources with nominal values of area input parameters. The performance of PID controller is found to be the best one for the studied power system models. It is also revealed that the performance of the interconnected two-area power system with AC–DC tie line is better in comparison to AC tie line.