Reheat Stage Research Articles

CO2 emission characteristics modeling and low-carbon scheduling of thermal power units under peak shaving conditions

To accommodate the high penetration of renewable power, the operational flexibility of thermal power units is highly required by the power system, so thermal power units frequently operate under peak shaving conditions. The CO2 emission characteristics of a thermal power unit are significantly influenced by the load factor, and also by the installed capacity and design parameters of the thermal power unit. Therefore, detailed CO2 emission characteristics of thermal power units should be modeled and considered in the low-carbon scheduling of the power system. In this study, thermal power units are classified by live steam parameters, installed capacities, reheat stages, cooling modes, and operation modes, and the models of detailed CO2 emission characteristics are developed and validated. The turbine isentropic efficiency, boiler thermal efficiency, and auxiliary power consumption are comprehensively considered in the CO2 emission model. A new indicator is defined to evaluate the reduction of carbon emissions in a power system when a TPU accommodates per unit of renewable power generation, and an optimization method for low-carbon scheduling based on it is proposed. Finally, a reference case study is conducted. Results show that the total carbon emissions for a day of the proposed low-carbon scheduling method are 0.06 %−0.20 % less than the efficiency priority method, and 1.53 %−2.36 % less than the capacity weighting method.

Costs versus revenues of flexibility enhancement techniques for thermal power units in electricity-carbon joint markets

Thermal power units (TPUs) are required to enhance operational flexibility to ensure power grids accommodate the increasing penetration of intermittent renewables. The flexibility enhancement includes increasing peak shaving depth, increasing ramp rate, or both. In electricity-carbon joint markets, increasing peak shaving depth means TPUs can generate less electricity during low-tariff periods while increasing ramp rate means TPUs can respond faster to changes in electricity tariffs. Flexibility enhancement brings additional revenues, but also additional investments. The tradeoff between costs and revenues is important for the construction of sustainable power systems mainly based on renewables, but limited literature models them. To address this gap, variable costs, fixed costs, revenues, and an optimization model for maximum profits are proposed and modeled. Then the economic applicability of different flexibility enhancement aspects is evaluated by comparing the maximum profit increase for a day before and after the flexibility enhancement of TPUs. Furthermore, the profitability of applying different flexibility technologies under the same investments is analyzed, obtaining the optimal flexibility enhancement route. The proposed method is applied to TPUs with different live steam parameters, installed capacities, and reheat stages. Numerical simulations provide detailed economic analysis and optimal flexibility enhancement routes for TPUs in electricity-carbon joint markets.

Tri-Loop design and thermoeconomic analysis for the high temperature gas cooled nuclear reactor coupling energy storage system

Thermal energy storage is a proposed solution that enables nuclear power plants to adjust their output without altering power levels. This technology manages fluctuations in the power generation process by storing generated heat above demand levels until it is required to produce steam. Despite the initial investment needed for infrastructure construction, these costs are easily offset by the ultimate returns, especially when efficiency is improved to 85% to 90%. In the context of nuclear power plant applications, helium molten salt energy storage systems demonstrate significant potential as an innovative power generation configuration. In this study, three cycle systems—helium, molten salt, and water (steam)—were employed to investigate and optimize the performance of the system. A series of modeling and simulation processes were conducted using EBSILON software to explore the impact of various parameters (such as pressure, reheat stages, and temperature) on the thermal efficiency of the power plant under both design and off-design conditions. To further study the system's performance, a thermo-economic analysis method based on the second law of thermodynamics was adopted. A thermal-economic analysis model was established, and a fire use analysis was performed on key equipment under representative conditions. Through this approach, we identified the distribution of fire use losses within the system, with the steam generator being the primary contributor to fire use losses among the three systems. Through comprehensive analysis of the simulation results, we conclude that the system exhibits outstanding thermal-economic performance when high-pressure parameters are combined with high temperature. This insight is crucial for modeling and optimizing the construction of nuclear power plants in China, providing a more comprehensive understanding of factors influencing thermal efficiency and contributing to more informed decision-making for the design and operation of tri-generation nuclear power stations.

An optimization of efficient combined cycle power generation system for fusion power reactor

Fusion power plants can meet the energy demands of the world. The high thermal performance of a power generation system is still a challenge and one of the developing trends with a fusion reactor due to the high outlet temperature. A combined cycle system has been optimized to work at high outlet temperature and pressure of fusion power reactor with thermal power of 2500 MWth and its input parameter has been optimized along with impact of partial load to achieve high thermal performance very first time. The combined cycle based on the concept of two stages of expansion in the closed-Brayton-cycle and two reheaters in the Rankine cycle named Schematic-IV with the higher thermal performance of 58.19% as compared to Schematic-I, II and III has been proposed for a fusion power reactor. The increase in more than one expansion stage and reheat stage is not economical because it increased the thermal performance by about half of performance as compared to one. The effect of isentropic efficiency of compressor and heat rate have been investigated to validate the thermodynamic model and calculations. The optimized thermal performance of the combined cycle is 58.19% at a feed water mass flow rate of 592 kgs−1 and steam outlet temperature of 277 °C in the combined cycle. The heat rate decreased and thermal performance increased with the mass flow rate verifying that the thermodynamic model is correct. The thermodynamic analysis of the combined cycle-based nuclear reactor provides insights for better system thermal performance and reveals the effect of key parameters on the system performance.

Thermodynamic, exergetic and environmental evaluation and optimization of a bio-fuel fired gas turbine incorporated with wind energy derived hydrogen injection

The fluctuating nature of wind energy and shortage of biomass resources, as two types of renewables, can be fulfilled via their hybridization. In this respect, present research proposes a hybrid biomass/wind energy driven power generation framework based on combined gas turbine-Rankine cycle scheme. The gas turbine includes a reheat stage where the produced hydrogen is added to the combustion chamber for increasing flue gas temperature to enhance output power. The injected hydrogen is generated via a water electrolyzer which is powered by electricity from the wind turbines. The proposed scheme of biomass/wind powered system leads to a reduction in biomass consumption and will fulfill the fluctuations and non-continuous availability of wind energy. To appraise the feasibility of developed hybrid scheme, thermodynamic first and second law-based analyses were performed. Also, the exergo-environmental evaluation of the hybrid plant is conduced using three exergo-environmental indices. Finally, optimum operation conditions of the proposed hybrid plant is determined based on the minimization of environmental damage index. The results under optimum operation indicate that, the proposed hybrid power generation plant yields exergy efficiency of 47.35 % with environmental damage index of 0.0104.

Computation and prediction of intrinsic thermoacoustic oscillations associated with autoignition fronts

A sequential combustor architecture consists of two longitudinally staged combustion zones featuring a propagation-stabilized flame in the first stage and an autoignition-stabilized flame in the second (reheat) stage. This layout allows for increased fuel flexibility compared to single-stage systems and enables clean and efficient combustion of carbon-free fuels such as hydrogen. Interactions between the autoignition-stabilized flame and the acoustic field created by the unsteady ignition front and the surrounding boundaries can result in self-sustained (thermoacoustic) flame oscillations in the reheat stage of the sequential burner, causing performance losses and structural damage. In this paper, an intrinsic flame-acoustic feedback mechanism causing self-sustained thermoacoustic oscillations in a reheat combustor is studied. The intrinsic thermoacoustic feedback is established when an acoustic wave generated by the unsteady ignition front travels upstream and introduces local temperature, pressure and velocity perturbations in the unburnt mixture. These modulate the ignition chemistry and the front kinematics and thus, in turn, act as a new source of perturbation for the ignition front that generates heat release rate oscillations and upstream-traveling acoustic disturbances, closing the feedback loop. Compressible reactive Euler equation computations of autoignition fronts in a simple one-dimensional reheat combustor configuration with fully non-reflecting boundaries are first performed to demonstrate and characterize the intrinsic thermoacoustic oscillations associated with autoignition fronts. These computations show that the autoignition front exhibits distinct harmonic thermoacoustic oscillations which tend to become unstable at some conditions. Next, frequencies and growth rates of the intrinsic thermoacoustic oscillations in the linear regime are predicted using a hybrid approach with flame response transfer functions taken from a forced Euler calculation and using a linearized Euler equation framework to describe the combustor acoustic field. The predictions of the intrinsic thermoacoustic eigenvalue from the linearized Euler equation framework show good agreement with the linear behaviour of these oscillations observed in the Euler computations. The findings of the present work are useful both from a fundamental standpoint for prediction of intrinsic thermoacoustic instabilities and from an industrial perspective for prevention of thermoacoustic instabilities in staged combustion systems.

The Influence of the Soaking Temperature Rotary Forging and Solution Heat Treatment on the Structural and Mechanical Behavior in Ni-Rich NiTi Alloy.

The structural and thermophysical characteristics of an Ni-rich NiTi alloy rod produced on a laboratory scale was studied. The soak temperature of the solution heat-treatment steps above 850 °C taking advantage of the precipitate dissolution to provide a matrix homogenization, but it takes many hours (24 to 48) when used without thermomechanical steps. Therefore, the suitable reheating to apply between the forging process steps is very important, because the product’s structural characteristics are dependent on the thermomechanical processing history, and the time required to expose the material to high temperatures during the processing is reduced. The structural characteristics were investigated after solution heat treatment at 900 °C and 950 °C for 120 min, and these heat treatments were compared with as-forged sample structural characteristics (one hot deformation step after 800 °C for a 30 min reheat stage). The phase-transformation temperatures were analyzed through differential scanning calorimetry (DSC), and the structural characterization was performed through synchrotron radiation-based X-ray diffraction (SR-XRD) at room temperature. It was observed that the solution heat treatment at 950 °C/120 min presents a lower martensitic reversion finish temperature (Af); the matrix was fully austenitic; and it had a hardness of about 226 HV. Thus, this condition is the most suitable for the reheating stages between the hot forging-process steps to be applied to this alloy to produce materials that can display a superelasticity effect, for applications such as crack sensors or orthodontic archwires.

Performance simulation of a double-reheat Rankine cycle mercury turbine system based on exergy

In this paper, a performance investigation of a Rankine cycle mercury turbine system operating with methane and including two closed feed mercury heaters, one open feed mercury heater and three turbines is comprehensively performed. The most known performance specifications such as ecological coefficient of performance, exergy efficiency, exergy destruction, net power and net power density, and are utilised to examine and optimise the performance of the system. The influences of boiler and condenser temperatures, the first and second reheat stage temperatures, extracted mercury temperature on the performance properties of the system have been comprehensively investigated. Beside the mathematical model investigated in the paper, an artificial neural network (ANN) model is also presented and it is shown that a good approximation is computed with only five parameters.

COMPARATIVE ENERGY AND EXERGY ANALYSIS OF A POWER PLANT WITH SUPER-CRITICAL AND SUB-CRITICAL

The aim of this study that how to effect live steam parameters reheat and feed water preheater numbers on efficiencies of energy and exergy at coal-fired power plants. Moreover, two desuperheaters and a regenerative turbine are added USCPP (Case 3) to approach best results. Soma Power Plant (Case 1) consists of one reheat stage, two HPRHs and four LPRHs with one DEA. It is operated sub-critic and coal is used for a fuel. Live steam conditions of Soma Power Plant set at 13,92 MPa and 540 °C, and the reheat steam is reheated to 540 °C. Supercritical Power Plant (Case 2) consists of the same main components of Case 1. However, steam parameters of Case 2 are increased to 262.5 Bar and 600 °C to determine impact of the steam parameters on power plant efficiencies. USCPP which consists of two reheat stages, four HPRHs, six LPRHs with one DEA is designed to generate live steam under nominal conditions of 30 Bar and 600 °C. Besides, reheat steam are heated to 620 °C. Simulations have been carried out Ebsilon Professional software and pressure drops at preheaters and reheats are also considered. Some assumptions are made in the analysis. The thermal and exergy efficiencies of USCPP increase by 9.241 and 8.06 percentage points compared with Soma power plant, respectively. The results of this study that live steam parameters which are increased from sub-critical values to super-critical values have enormous influence on energy and exergy efficiencies. Secondly, adding second reheat stage has positive impact to improve power plant efficiencies. Finally, augmenting feed water preheater number, adding two desuperheater and one regenerative turbine increase power plant efficiencies. However, optimum numbers of feed water preheaters are determined considering economic parameters.

Thermodynamic Analysis of Supercritical CO2 Power Cycle with Fluidized Bed Coal Combustion

Closed supercritical carbon dioxide (S-CO2) Brayton cycle is a promising alternative to steam Rankine cycle due to higher cycle efficiency at equivalent turbine inlet conditions, which has been explored to apply to nuclear, solar power, waste heat recovery, and coal-fired power plant. This study establishes 300MW S-CO2 power system based on modified recompression Brayton cycle integrated with coal-fired circulating fluidized bed (CFB) boiler. The influences of two stages split flow on system performance have been investigated in detail. In addition, thermodynamic analysis of critical operating parameters has been carried out, including terminal temperature difference, turbine inlet pressure/temperature, reheat stages, and parameters as well as compressor inlet pressure/temperature. The results show that rational distribution of split ratio to the recompressor (SR1) achieves maximal cycle efficiency where heat capacities of both sides in the low temperature recuperator (LTR) realize an excellent matching. The optimal SR1 decreases in the approximately linear proportion to high pressure turbine (HPT) inlet pressure due to gradually narrowing specific heat differences in the LTR. Secondary split ratio to the economizer of CFB boiler (SR2) can recover moderate flue gas heat caused by narrow temperature range and improve boiler efficiency. Smaller terminal temperature difference corresponds to higher efficiency and brings about larger cost and pressure drops of the recuperators, which probably decrease efficiency conversely. Single reheat improves cycle efficiency by 1.5% under the condition of 600°C/600°C/25Mpa while efficiency improvement for double reheat is less obvious compared to steam Rankine cycle largely due to much lower pressure ratio. Reheat pressure and main compressor (MC) inlet pressure have corresponding optimal values. HPT and low pressure turbine (LPT) inlet temperature both have positive influences on system performance.

Thermodynamic and economic evaluation of reheat and regeneration alternatives in cogeneration systems of the Brazilian sugarcane and alcohol sector

This work makes a technical and economic evaluation of incorporation of reheating and regeneration, as a way to increase efficiency of energetic systems and bagasse surplus, in cogeneration systems of Brazilian sugar and ethanol sector. Four scenarios were analyzed: Conventional (C0), with Reheat (C1), Regenerative (C2) and with Reheat and Regeneration (C3). Some of thermodynamic indicators used in evaluation were Surplus Bagasse Index and Exergetic Efficiency, for economic evaluation the Monte Carlo Method was used to give a Net Present Value (NPV) > 0 for each scenario. Technical evaluation indicates that Reheating (C1) increases bagasse surplus by 39.9% and exergetic efficiency by 1.90%, with respect to C0. Incorporation of 1–8 regenerators (C2) increases surplus bagasse and exergetic efficiency in the ranges of 103–160% and 5.03–8.07%, respectively. Reheat stage incorporation of 1–8 regenerators (C3) increases surplus bagasse in the range of 121–166% and increases exergetic efficiency in a range of 5.91–8.46%. Finally, it was estimated the potential of additional electric power generation during off-season and second generation ethanol production from surplus bagasse, with satisfactory results.

Particle swarm optimisation-based parameters optimisation of PID controller for load frequency control of multi-area reheat thermal power systems

The current study presents the load frequency control (LFC) of multi-area reheat thermal power system with proportional-integral-derivative (PID) controller. The interconnected control areas are provided with a single stage reheat turbine in all areas. The proportional gain (KP), integral gain (KI) and derivative gain (KD) values of the PID controller are simultaneously optimised using recent and powerful evolutionary computational intelligence technique, namely the particle swarm optimisation (PSO) algorithm. The superiority of the PSO-based PID controller has been proved by comparing its performance to recent modern optimisation techniques such as hill climbing (HC) algorithm and genetic algorithm (GA) tuned controllers for the same multi-area thermal power system. For the analysis, the time domain specification and 1% step load perturbation (1% SLP) are considered in thermal area 1. The simulation result showed that the proposed PSO-based PID controller provides superior dynamic response over other optimisation technique (HC and GA)-based PID controller.

Automatic generation control of a multi-area system using ant lion optimizer algorithm based PID plus second order derivative controller

This article presents the automatic generation control of an unequal three area thermal system. Single stage reheat turbines and generation rate constraints of 3%/min are considered in each control area. Controllers such as Integral (I), Proportional – Integral (PI), Proportional – Integral – Derivative (PID), and Proportional – Integral – Derivative Plus Second Order Derivative (PID+DD) are treated as secondary controllers separately. A nature inspired optimization technique called Ant Lion Optimizer (ALO) algorithm is used for simultaneous optimization of the controller gains. Comparison of dynamic responses of frequencies and tie line powers corresponding to ALO optimized I, PI, PID and PID+DD controller reveal the better performance of PID+DD controller in terms of lesser settling time, peak overshoots as well as reduced oscillations. Robustness of the optimum gains of best controller obtained at nominal conditions is evaluated using sensitivity analysis. Analysis exposed that the optimum PID+DD controller gains obtained at nominal are robust and not necessary to reset again for changes in loading, parameter like inertia constant (H), size and position of disturbance. Furthermore, the performance of PID+DD controller is found better as compared to PID controller against random loading pattern condition.

Second Law Based Thermodynamic Performance analysis of Steam Power Cycle

The generation of mechanical power had been a challenge for mechanical engineers and a great deal of attention has been focused on designing system for power generation. Thermal power cycles are important devices used in practical engineering application for thermal power generation and control of environment. Several thermodynamic approaches are possible to analyze the performance of these cycles. The most traditional approach is the first law of thermodynamics or energy balance analysis; however, this concerned only with the conversion of energy, and therefore it can not be show how or where irreversibility in a system or process occur. Second law analysis is another well-known method used to analyze thermodynamic cycles, but to some, it may be still new. Unlike first law analysis, second law analysis determines the magnitude of irreversible processes in a system, and thereby provides an indicator that the points the direction in which the engineers should concentrate their efforts to improve the performance of thermodynamic systems. This thesis is an attempt to physically understand and evaluate the internal irreversibilities due to heat transfer and fluid flow in various thermal power cycle used for power generation. This thesis present investigations on thermodynamic modelling and effects of irreversibilities in thermal power cycles using the concept of exrgy analysis and entropy generation. Detail literature review on second law analysis of thermal power cycles is reported in Section I.0 First and second law analysis of stem power cycle, gas turbine cycle, combine Brayton/Rankine power cycle, indirect fired air turbine multi stage…. have been carried out. Analytical expressions for the performance parameters involving the relevant variables for these systems under given conditions, corresponding to available power output and exergy destruction in the system, have been obtained. Detailed parametric study has been done and result are presented. This study include the effect of pressure ratio, cycle temperature ratio, number of reheat stages, pressutre drop in heat transfer devices, and the refrigeration temperature on the performance parameters of the thermal power cycles. Second law based performance assessment of regenerative-reheat steam power cycle has been carried out in terms of irreversibility analysis. The reduction in irreversible losses with the addition of backward, cascade type feed water heater and a reheat options are compared with a conventional first-law assessment. The second law indicate that the maximum exergy is destroyed in the boiler and that these thermodynamic losses are significantly reduced by incorporating feed water heater. The incorporation of feed water heating results in a reduction of total irreversility rate of the plant by 18%. The corresponding improvement in thermal efficiencies is 12%. These two values are enhanced to 24% and 14% respectively, by the incorporation of reheat in addition to regeneration.

Solid Particle Erosion in the Reheat Stage of the Steam Turbine

Solid Particle Erosion in the Reheat Stage of the Steam Turbine

Exergoeconomic analysis and optimization of a triple-pressure combined cycle plant using evolutionary algorithm

Among power generation systems, CCPPs (combined cycle power plants) are attractive due to their higher efficiency and lower environmental impacts. Optimization process is a promising manner in order to find the best performance criteria of complex energy conversion systems. In present paper, exergoeconomic analysis and optimization of a triple-pressure combined cycle plant with one reheat stage is under investigation. The objective function which is utilized in the optimization study is the total cost rate of the plant. The results show that optimization process leads to an increase of about 3% in both energetic and exergetic efficiencies and also, a reduction of about 9% in the cost criteria. In addition, the specific cost of product of the plant is reduced from 21.48 (€/h) for the base case to 20.90 (€/h) for the optimum case; thus, the optimization process causes about 3% decrement in the specific cost of product and consequently cost of produced electricity.

Study on Erosion Characteristics of Solid Particles in the First Reheat Stage Blades of a Supercritical Steam Turbine

Reducing solid particle erosion (SPE) of blades is one of the most urgent problems for supercritical steam turbine power generation technology. Based on the erosion rate models and the particle rebound models of blade materials obtained through the accelerated erosion test under high temperature, erosion characteristics of the first reheat stage blades in a supercritical steam turbine was simulated and analyzed by three-dimensional numerical simulation method in this paper. The influence of operating conditions, particle size distribution in the inlet of nozzle, and axial clearance between vanes and rotating blades on the erosion distribution of cascade were explored quantitatively. Results show that the erosion damage of the first-reheat stage stator is mainly caused by suction surface impingement from oxide particles. In designed loading condition, small and medium size of particles mainly eroded the trailing edge (TE) of nozzle pressure surface, while large particles mainly impinge the leading edge (LE) of rotating blades and the TE of vane suction surface, and erosion increase along the blade height. When the turbine is running under part-load condition, particle impingement angle on stator pressure surface is basically unchanged, while impingement velocity slightly reduced. However, the amount of particles that impinge the stator TE suction side after their first-time impingement on rotor LE increase rapidly, leading to the more severe erosion damage of stator suction surface. The particle size distribution in the inlet of nozzle has a significant effect on the erosion simulation of first reheat stage blades, and the size distribution sampled in one unit may not be used to other units. When axial clearance changes, the erosion weight loss of vane pressure surface near TE is basically held constant, while the erosion weight loss in vane suction surface near TE decreases with the increase of axial clearance. For the supercritical 600 MW unit simulated in this article, the antiSPE performance and the unit efficiency can be balanced well when the axial clearance increases to 13 mm. The results in this paper will provide a technology basis for reducing oxide particle erosion in the first reheat stage blades of supercritical steam turbine.

Reheat-Air Brayton Combined Cycle Power Conversion Design and Performance Under Nominal Ambient Conditions

Modern large air Brayton gas turbines have compression ratios ranging from 15 to 40 resulting in compressor outlet temperatures ranging from 350 °C to 580 °C. Fluoride-salt-cooled, high-temperature reactors, molten salt reactors, and concentrating solar power can deliver heat at temperatures above these outlet temperatures. This article presents an approach to use these low-carbon energy sources with a reheat-air Brayton combined cycle (RACC) power conversion system that would use existing gas turbine technology modified to introduce external air heating and one or more stages of reheat, coupled to a heat recovery steam generator to produce bottoming power or process heat. Injection of fuel downstream of the last reheat stage is shown to enable the flexible production of additional peaking power. This article presents basic configuration options for RACC power conversion, two reference designs based upon existing Alstom and GE gas turbine compressors and performance of the reference designs under nominal ambient conditions. A companion article studies RACC start up, transients, and operation under off-nominal ambient conditions.

Development of a Simulation Program to Optimise Process Parameters of Steam Power Cycles

Conventional coal-based thermal power plants have an average overall efficiency in the range of 35-38 %. Any increase in the percent efficiency of these power plants, is subjected to constraints posed by maximum and minimum temperatures, which are restricted by the creep property of materials and ambient temperature, respectively. Hence, an increase of efficiency beyond certain limits is not possible without optimising the process parameters associated with reheat and regenerative cycles. In this work, an attempt is made to optimise reheat and regenerative cycle process parameters such as, reheat pressure, tapping pressure of bled steam, and mass fraction of bled steam, in order to achieve maximum cycle efficiency. The optimisation of the process parameters was achieved by developing a simulation program using Microsoft Visual Studio. This program takes into account isentropic efficiencies of turbines and pumps and pressure drop in the boiler, and it can be used to simulate the optimum operating conditions of multi-stage reheat & regenerative cycle based thermal power plants. A comparison between the efficiencies of eight kinds of steam power cycles, at optimised conditions, has been made for different boiler pressures and steam temperatures at the turbine inlet. This comparison can aid power plant designers in choosing appropriate steam power cycles for a given set of operating conditions. It is observed that the results obtained from the program, such as, the optimum reheat pressures for two stage reheat cycles and optimum bled steam tapping pressures for two stage regenerative cycles are in good agreement with the published literature.

Optimal Tuning of PID Controllers for Hydrothermal Load Frequency Control Using Ant Colony Optimization

This paper proposes a novel Artificial Intelligence technique known as Ant Colony Optimization (ACO) for optimal tuning of PID controllers for load frequency control. The design algorithm is applied to a hydrothermal power system consisting of two control areas one hydro and the other is thermal with reheat stage. To make the system in realistic form, the system nonlinearities represented by Generation Rate Constraint (GRC), Dead Band, wide range of parameters are introduced. Three different cost functions have been suggested for tuning the PID controllers. The system has been tested for various load changes to reveal the effectiveness and robustness of the proposed technique.