Isolated Wind Diesel Hybrid Power Research Articles

Frequency and Voltage Coordinated Control for Isolated Wind–Diesel Power System Based on Adaptive Sliding Mode and Disturbance Observer

Due to frequency and voltage fluctuation resulting from the renewable energy variety, parameter uncertainty, and system disturbance, a novel coordinated control strategy is proposed to improve the dynamic stability of isolated wind–diesel hybrid power system. So, the frequency and voltage can also be regulated by taking advantage of adaptive sliding mode (SM) method and disturbance observer (DOB), which are based on the established whole hybrid system mathematical model. First, the DOB is constructed to estimate the source–load disturbance for isolated wind–diesel power system model. Second, the coordinated control strategy is constructed according to the estimated source–load disturbance value and state control model by using adaptive SM algorithm. Then, the output vector signal of adaptive SM controller is added to the synchronous generator side and the static synchronous compensator, respectively; therefore, the proposed coordinated control strategy can regulate the frequency and voltage simultaneously. Experiment studies are performed by real-time digital simulator to validate the effectiveness of the proposed coordinated control strategy for the isolated hybrid system under different operation points.

Automatic reactive power control of isolated wind–diesel hybrid power system using artificial bee colony and gray wolf optimization

ABSTRACTThis paper investigates the artificial bee colony (ABC)- and gray wolf optimization (GWO)-based robust controllers in an isolated winddiesel hybrid power system (IWDHPS). The IWDHPS comprises a wind energy conversion system (WECS) and a diesel engine set. A permanent-magnet induction generator and a synchronous generator are used for power generation with WECS and diesel engine set, respectively. The voltage fluctuations at the generator terminal occur because of the mismatch between generated and consumed reactive power in the system, which further causes a reduction in the quality and stability of the power supply. An automatic voltage regulator (AVR) and a static synchronous compensator (STATCOM) are utilized to suppress these voltage fluctuations in the considered system. Both AVR and STATCOM are equipped with proportional integral (PI) controllers with a single input. The performance and robustness conditions of the control system are expressed as the optimization problem based on the H loop shaping. The ABC and GWO algorithms are applied to solve the optimization problem and to achieve the values of PI controllers for AVR and STATCOM simultaneously. The proposed controller performance is compared with the performance of the bacterial foraging optimization algorithm, particle swarm optimization algorithm, genetic algorithm, and conventional based controller, for the same IWDHPS.

Reactive Power Control of Isolated Wind-diesel Hybrid Power System Using Grey Wolf Optimization Technique

In this paper reactive-power control of an isolated wind–diesel hybrid power system is presented. The system generates electrical power from wind by an induction generator (IG) and a synchronous generator (SG) is present for a diesel-generator (DG) set. The mathematical model of the reactive-power balance is presented. In an isolated system IG consumes reactive power which is supplied by the static var compensator (SVC). It also provides reactive power support for load variations. In the type III SVC used here, the proportional integral (PI) controller gains are optimized using Grey Wolf Optimization (GWO) algorithm. Three objective functions namely Integral Time Absolute Error (ITAE), Integral Square Error (ISE) and Integral Time Square Error (ITSE) are considered and their performance is compared in a hybrid system and with earlier work.

Evolutionary optimization technique for comparative analysis of different classical controllers for an isolated wind–diesel hybrid power system

In this paper, the considered hybrid power system (HPS) is having a wind turbine generator, a diesel engine generator (DEG) and a storage device (such as capacitive energy storage). This paper presents a comparative study of frequency and power control for the studied isolated wind–diesel HPS with four different classical controllers for the pitch control of wind turbines and the speed governor control of DEG The classical controllers considered are integral, proportional-integral, integral-derivative and proportional-integral-derivative (PID) controller. A quasi-oppositional harmony search (QOHS) algorithm is proposed for the tuning of the controller gains. The comparative dynamic simulation response results indicate that better performance may be achieved with choosing PID controller among the considered classical controllers, when subjected to different perturbation. Stability and sensitivity analysis, presented in this paper, reveals that the optimized PID controller gains offered by the proposed QOHS algorithm are quite robust and need not be reset for wide changes in system perturbations.

Modeling and seeker optimization based simulation for intelligent reactive power control of an isolated hybrid power system

Seeker optimization algorithm (SOA) is a novel heuristic population-based search algorithm based on the concept of simulating the act of human searching. In SOA, the acts of human searching capability and understanding are exploited for the purpose of optimization. In this algorithm, search direction is based on empirical gradient by evaluating the response to the position changes and the step length is based on uncertainty reasoning by using a simple fuzzy rule. In this paper, effectiveness of the SOA has been tested for optimized reactive power control of an isolated wind–diesel hybrid power system model. In the studied power system model, a diesel engine based synchronous generator (SG) and a wind turbine based induction generator (IG) are used for the purpose of power generation. IG offers many advantages over the SG but it requires reactive power support for its operation. So, there is a gap between reactive power demand and its supply. To minimize this gap between reactive power generation and its demand, a variable source of reactive power such as static VAR compensator (SVC) is used. The SG is equipped with IEEE type-I excitation system and dual input power system stabilizer (PSS) like IEEE-PSS3B. The performance analysis of a Takagi–Sugeno fuzzy logic (TSFL)-based controller for the studied isolated hybrid power system model is also carried out which tracks the degree of reactive power compensation for any sort of input perturbation in real-time. In time-domain simulation of the investigated power system model, the proposed SOA–TSFL yields on-line, off-nominal coordinated optimal SVC and PSS parameters resulting in on-line optimal reactive power control and terminal voltage response. The performance of the proposed controller, with the influence of signal transmission delay, has also been investigated.

Performance Investigation of Isolated Wind–Diesel Hybrid Power Systems With WECS Having PMIG

This paper presents the automatic reactive power control of isolated wind-diesel hybrid power systems having a permanent-magnet induction generator for a wind energy conversion system and a synchronous generator for a diesel generator set. To minimize the gap between reactive power generation and demand, a variable source of reactive power is used such as a static synchronous compensator. The mathematical model of the system used for simulation is based on small-signal analysis. Three examples of the wind-diesel hybrid power system are considered with different wind power generation capacities to study the effect of the wind power generation on the system performance. This paper also shows the dynamic performance of the hybrid system with and without change in input wind power plus 1% step increase in reactive power load.

Fuzzy Based Gain Scheduled PI Controller for an Isolated Wind Diesel Hybrid Power System

Fuzzy Based Gain Scheduled PI Controller for an Isolated Wind Diesel Hybrid Power System

Fuzzy Based Gain Scheduled PI Controller for an Isolated Wind Diesel Hybrid Power System

Fuzzy Based Gain Scheduled PI Controller for an Isolated Wind Diesel Hybrid Power System

Performance of Statcom in an Isolated Wind–Diesel Hybrid Power System

The paper presents study of an isolated hybrid power system using a proportional integral (PI) controller with a static synchronous compensator (STATCOM) for reactive power control to maintain constant voltage at the generator terminals. The renewable energy sources such as solar, wind, bio-mass, etc. that are intermittent in nature use induction generator as electro-mechanical device for conversion of mechanical to electrical energy, but reactive power is required for the operation of the induction generator in addition to the reactive power required by the load. The synchronous generator used in hybrid system for generating power through diesel system is supplying reactive power to the system partially; therefore, another source of reactive power is required to fulfill this demand. The paper also shows the dynamic performance of the hybrid system both for constant and variable slip conditions and 1% step change in reactive power load by considering wind–diesel hybrid power system as an example.

Study of an isolated wind–diesel hybrid power system with STATCOM by incorporating a new mathematical model of PMIG

SUMMARYThis paper presents automatic reactive power control of an isolated wind–diesel hybrid power system. A synchronous generator is used for power generation from diesel and a permanent‐magnet induction generator (PMIG) is used for electric power generation from wind turbine. A new mathematical model is developed to incorporate the effect of permanent‐magnet of the PMIG in the generation of reactive power. To eliminate the gap between reactive power generation and demand, a variable source of reactive power is used such as static synchronous compensator (STATCOM). A study on the wind–diesel system is conducted based on small signal analysis by considering IEEE type‐1 excitation system for the synchronous generator. The paper also shows the dynamic performance of the hybrid system both for constant and variable slip conditions and 1% step change in reactive power load. Copyright © 2011 John Wiley & Sons, Ltd.

DMLHFLC (Dual mode linguistic hedge fuzzy logic controller) for an isolated wind–diesel hybrid power system with BES (battery energy storage) unit

Abstract Design of DMLHFLC (dual mode linguistic hedge fuzzy logic controller) for an isolated wind–diesel hybrid power system with BES (battery energy storage) unit is proposed in this paper. The design methodology is a hybrid model based on the concepts of linguistic hedges and hybrid genetic algorithm-simulated annealing algorithms. Dual-mode concept is also incorporated in this proposed controller because it can improve the system performance. The system is simulated and the results are compared with proportional plus integral controller and FLC (fuzzy logic controller). Sensitivity analysis and robustness of the controller is tested. The results prove the effectiveness of the proposed controller.

Design of Dual Mode Linguistic Hedge Fuzzy Logic Controller for an Isolated Wind-Diesel Hybrid Power System with Lossy Magnetic Energy Storage Unit

In this paper, a dual mode linguistic hedge fuzzy logic controller for an isolated wind-diesel hybrid power system with lossy magnetic energy storage unit is proposed. The design methodology is a hybrid model based on the concepts of dual mode control, the linguistic hedges and the hybrid genetic algorithm-simulated annealing algorithms. The system is simulated with the dual mode linguistic hedge fuzzy logic controller and the frequency deviation resulting from the step load disturbance is presented. It is observed from the result that with the application of the proposed controller, the system performance is improved significantly. It has been also found that the proposed controller is less sensitive to the changes in the parameters of the system and also under different operating modes of the hybrid power system.

Dual mode linguistic hedge fuzzy logic controller for an isolated wind–diesel hybrid power system with superconducting magnetic energy storage unit

A design of dual mode linguistic hedge fuzzy logic controller for an isolated wind–diesel hybrid power system with superconducting magnetic energy storage unit is proposed in this paper. The design methodology of dual mode linguistic hedge fuzzy logic controller is a hybrid model based on the concepts of linguistic hedges and hybrid genetic algorithm-simulated annealing algorithms. The linguistic hedge operators are used to adjust the shape of the system membership functions dynamically and can speed up the control result to fit the system demand. The hybrid genetic algorithm–simulated annealing algorithm is adopted to search the optimal linguistic hedge combination in the linguistic hedge module. Dual mode concept is also incorporated in the proposed controller because it can improve the system performance. The system with the proposed controller was simulated and the frequency deviation resulting from a step load disturbance is presented. The comparison of the proportional plus integral controller, fuzzy logic controller and the proposed dual mode linguistic hedge fuzzy logic controller shows that, with the application of the proposed controller, the system performance is improved significantly. The proposed controller is also found to be less sensitive to the changes in the parameters of the system and also robust under different operating modes of the hybrid power system.

Automatic Reactive-Power Control of Isolated Wind–Diesel Hybrid Power Systems

This paper presents an automatic reactive-power control of an isolated wind-diesel hybrid power system having an induction generator (IG) for a wind-energy-conversion system and synchronous generator (SG) for a diesel-generator (DG) set. To study the effect of the size of the wind-power generation on the system performance, three examples of the hybrid system are considered with different wind-power-generation capacities. The mathematical model of the system using reactive-power-flow equations is developed. Three different types of static var compensators (SVCs) commonly used in conventional power system along with IEEE type-I excitation are considered to compare their performance in a hybrid system

97/04808 Load frequency control of isolated wind diesel hybrid power systems: Bhatti, T. S. et al. Energy Convers. Mgmt, 1997, 38, (9), 829–837

97/04808 Load frequency control of isolated wind diesel hybrid power systems: Bhatti, T. S. et al. Energy Convers. Mgmt, 1997, 38, (9), 829–837

Load frequency control of isolated wind diesel hybrid power systems

In this paper, a load frequency controller is designed for isolated wind Diesel hybrid power systems, and its effect on the transient performance of the system is evaluated. The modelling of the system, consisting of a wind turbine induction generator unit and a Diesel engine synchronous alternator unit, is presented along with the controller, both for continuous and discrete control cases. Optimum parameter values are obtained for different hybrid power system examples with continuous and discrete load frequency control and with and without blade pitch controllers, using the integral square error criterion (ISE). It is shown that wind Diesel or multi-wind Diesel hybrid power systems, with blade pitch control mechanism and with continuous load frequency control, have better dynamic performance than any other configuration of the isolated wind Diesel hybrid systems. Finally, some of the transient responses of the systems are shown for optimum gain settings.