Wind-diesel Hybrid Power System Research Articles

Enhancing Frequency Regulation Support through Several Synthetic Inertial Approaches for WDPS

The aim of this paper is to propose an enhancement to the primary frequency control (PFC) of the San Cristobal Island hybrid wind–diesel power system (WDPS). Naturally, variable speed wind turbines (VSWT) provide negligible inertia. Therefore, various control strategies, i.e., modified synthetic inertial control, droop control and traditional inertial control, if introduced into VSWT, enable them to release hidden inertia. Based on these strategies, a WDPS has been simulated under seven different control strategies, to evaluate the power system performance for frequency regulation (FR). Furthermore, the student psychology-based algorithm (SBPA) methodology is used to optimize the WDPS control. The results show that modified synthetic inertial control is the most suitable approach to provide FR. However, further exhaustive research validates that droop control is a better alternative than modified synthetic inertial control due to the negligible system performance differences. In addition, droop control does not require a frequency derivative function in the control system. Therefore, the hybrid system is more robust. Moreover, it reduces the steady state error, which makes the power system more stable. In addition, a pitch compensation control is introduced in blade pitch angle control (BPAC) to enhance the pitch angle smoothness and to help the power system to return to normal after perturbations. Moreover, to justify the performance of hybrid WDPS, it is tested under certain real-world contingency events, i.e., loss of a wind generator, increased wind speed, fluctuating wind speed, and simultaneously fluctuating load demand and wind speed. The simulation results validate the proposed WDPS control strategy performance.

Dynamic performance improvement of an isolated wind-diesel system with intelligently controlled supercapacitor energy storage system

This paper aims to develop a supervisory control scheme to enhance the effectiveness and profitability of a small-rating super capacitor energy storage system (SCESS) used in load-frequency-control applications. The proposed approach, which uses one-step-ahead adaptive predictive control (APC), adeptly handles the operational limitations of the SCESS. For the purpose of online estimation of system parameters, the recursive least square (RLS) algorithm has been employed. The system can be characterized as a two input two output system, wherein the real and reactive powers required by the SCESS serve as control signals issued by the controller. The SCESS voltage is subject to constraints to limit energy trade within specific bounds. The proposed control scheme successfully maintains the voltage constraints of the SCESS while significantly reducing frequency and voltage deviations in the presence of two disturbances, viz; load disturbance and wind disturbance. The effectiveness of the proposed scheme is demonstrated through simulation experiments on an isolated hybrid wind diesel power system, which addresses several modeling and design aspects.

Symbiosis organisms search algorithm for reactive power compensation of STATCOM-PID assisted isolated wind integrated hybrid power system model

The paper is focused on development of intelligent reactive power control of an isolated wind-diesel hybrid power system (IWDHPS) model assisted by PID controlled static synchronous compensator (STATCOM). The reactive power disparity in the IWDHPS model happens due to the varying nature of demands among the different reactive components. The reactive power disparity has to overcome the voltage sag also. To avoid the voltage sag and improve the stability of the IWDHPS model, demand side management is required by appropriately compensate the reactive power. Considering this aspect, the main idea of the paper is to design a PID controlled STATCOM (STATCOM-PID) and tunes its parameters appropriately to optimize the reactive power. The key contribution done in this research study is the applicability of the novel Symbiosis Organisms Search (SOS) Algorithm for tuning the proportional, derivative and integral parameter of the PID controller which controls the STATCOM. To obtain optimal reactive power support, proper tuning of the parameters has been done with SOS algorithm and the performance of the proposed controller design using SOS is compared with state-of-the-art approaches to prove the effectiveness. The dynamic behavior of the studied IWDHPS model has been taken into investigation for its performance analysis.

Optimal wind power generation system by honey badger algorithm with differential evolution strategies

The purpose of this study is to build an optimal hybrid wind power system consisting of a permanent magnet direct-drive wind power generation unit, a hybrid energy storage system (HESS), a power electronic converter, and loads. Moreover, a reasonable control method is designed for each part, and a honey badger algorithm (HBA) with differential evolution strategies is employed to realize the coordinated control of each unit and improve the system stability. The real anti-interference capability of wind power system can be improved by the proposed HBA with differential evolution strategies (IHBA). Firstly, the wind hybrid system model is constructed, in which the wind power generation unit adopts the variable step climbing method to achieve the maximum power point tracking control; the HESS designs the power distribution method based on the bus voltage; the converter supplying energy to the AC load introduces the virtual synchronous generator (VSG) control strategy. Secondly, due to the existence of energy exchange in each unit of the system, VSG has more parameters and its control performance is influenced by the system itself, this study proposes HBA with differential evolution strategies for system parameter optimization and constructs an IHBA-VSG model with the objective of minimizing the bus voltage fluctuation value. The IHBA improves original honey badger algorithm by three mechanisms which are time control function, Gaussian variation factor and differential evolution strategy. Finally, the parameters obtained from the HBA with differential evolution strategies optimization search are substituted into the wind hybrid system, and the simulation system is built by MATLAB/Simulink. The simulation results show that when the environment of the system changes or the load on the AC side changes abruptly, the proposed control method can reduce the bus voltage fluctuation by 2.9%− 18.22% compared with the honey badger algorithm Optimized VSG (HBA-VSG), and can reduce the bus voltage fluctuation by 5.09%− 17.98% compared with the traditional droop control without considering the system interaction. This study can effectively improve the stability of wind power generation system and promote the development of new energy industry.

Synthesis of State/Output Feedback Event-Triggered Controllers for Load Frequency Regulation in Hybrid Wind–Diesel Power Systems

Hybrid power systems based on renewable energy sources and diesel generators are efficient solutions for supplying electricity to remote and off-grid locations. One of the most crucial problems in hybrid power systems is frequency regulation, which is established by balancing the supplied power with the load demand using the load frequency control approach. Since most feedback signals are analog and the control setups are digital, the resulting control system is a sampled-data system, which requires careful designs for both the control law and the sampling frequency to guarantee closed-loop stability. This paper is concerned with the state-feedback load frequency regulation for hybrid wind–diesel power systems under event-triggered implementation. It is assumed that the full state measurement is available for feedback and that sensors and controllers communicate over a shared digital network. To mitigate the communication load on the network, an event-triggering mechanism is constructed by emulation, based on the time-regularization principle in the sense that each consecutive triggering instant is speared by a specified minimum dwell time. The closed-loop system is described as a hybrid dynamical system to account for mixed dynamical behaviors naturally arising in networked control systems. By means of appropriate Lyapunov functions, the closed-loop stability is ensured under the proposed triggering rule. Moreover, the enforced dwell time between transmissions ensures that the accumulation of sampling times is prevented, which is crucial for the event-triggering condition to be implementable in practice. The required conditions to apply this technique are derived in terms of a linear matrix inequality. Numerical simulations on an isolated hybrid power system were implemented to demonstrate the efficiency of the proposed method. Comparative simulations with relevant techniques in the literature were carried out, which showed that the proposed approach can produce fewer transmission numbers over the network.

Diesel Governor Tuning for Isolated Hybrid Power Systems

In recent decades, renewable energy sources, such as wind power, have extraordinarily increased their participation in the energy mix throughout the world. This progression has played an important role in lowering the usage of fossil fuels. In addition, it has reduced environmental hazards and increased the emergence of hybrid power systems, mainly in remote areas. In some of these areas, diesel power plants were the only previous source of energy. Irrespective of the benefits, hybrid power systems might face problems such as frequency deviations. To contribute to reducing these problems, this paper presents a methodology to tune diesel engine governors using the Student Psychology-Based Algorithm. This proposed methodology enhances some metrics of controller performance, such as the integral square error, integral absolute error, and number of sign changes in the frequency derivative. This approach has been tested against different perturbations (step, ramp and random). To validate the effectiveness of the proposed approach, it has been simulated in relation to the San Cristobal Island (Ecuador) hybrid wind–diesel power system. The simulation results show that the governor tuned with the proposed approach provides a better system response.

Modeling and performance assessment of an isolated wind-diesel system with flywheel energy storage system

This paper proposes incorporation of a flywheel energy storage system (FESS) into hybrid wind-diesel power plant for system frequency and voltage response improvement. The impact of hybrid wind-diesel energy storage systems under various forms of disturbances, such as load disturbance, wind disturbance, wind park disconnection, and step variations in wind is presented and analyzed. The standard IEEE models for different components of hybrid wind diesel power system are considered. Simulations in the time domain are carried out in order to test the performance of proposed system. The positive impact of FESS used in wind-diesel hybrid power system is demonstrated through a series of simulation cases carried for various types of disturbances.

Adaptive fractional-order sliding-mode disturbance observer-based robust theoretical frequency controller applied to hybrid wind–diesel power system

This work presents design and theoretical analysis of an adaptive fractional-order sliding-mode disturbance observer (FO-SM-DOB)-aided fractional-order robust controller for frequency regulation of a hybrid wind–diesel based power system, considering endogenous/exogenous system disturbances. Adaptive FO-SM-DOB is designed to estimate unknown/uncertain lumped system disturbances, including parametric uncertainty and exogenous disturbances. Afterwards, an improved fractional-order sliding mode controller (FOSMC) augmented with the estimated output of FO-SM-DOB is designed and applied to accelerate system dynamics with minimum chattering in the control effort. The Mittag-Leffler stability theorem affirms the finite-time convergence of disturbance estimation error. Moreover, the closed-loop asymptotic stability of the overall control system has been guaranteed by applying Lyapunov argument. The effectiveness of the suggested resilient fractional-order nonlinear frequency controller is theoretically validated by performing an extensive comparative study with SMC, FOSMC (without DOB), state observer-based SMC (SOB-SMC), second-order SMC (without DOB), and conventional integer/fractional-order controllers. Simulation results establish the supremacy of the proposed resilient fractional-order nonlinear frequency controller over its other counterparts concerning fast disturbance rejection, weaker chattering, and a high degree of robustness against unknown lumped system disturbances. Further, to demonstrate the practicability and validate the effectiveness of the proposed control strategy, magnetic levitation system and IEEE 39-bus New England power system are considered and successfully tested on MATLAB platform.

Design, Sizing and Optimization of a Solar- Wind Hybrid Power System

Design, sizing and optimization of a solar-wind hybrid power system was carried out to determine its economic feasibility using Hybrid optimized model for electric renewable (HOMER) software aimed at selecting the most feasible configuration based on the net present cost to meet the load demand of 425 W for the appliances in a departmental office at Joseph Sarwuan Tarka University, Makurdi. The simulation results were used to develop a working prototype by sizing the four major components: the solar panels (350 W), a wind turbine (100 W), 2 battery systems of 12 V/200Ah and a charge controller (35.4 A) to regulate battery charging. The efficiencies of the wind turbine, PV solar panels and the inverter system were 48, 29.2 and 50 % respectively. The contribution of PV was 98 % and that of the wind turbine was 2 % due to low average wind speed (1.96 m/s at 15 m) from February to April. The results showed that solar energy contributed more to the charging of the inverter than the wind energy due to the high favorable solar insolation in the region. The optimized system configuration was chosen and this was based on the net present cost, levelized cost of energy and its renewable fraction respectively. The results demonstrated that the best hybrid combination consists of 0.35 kW PV Panels, 1 unit of 0.1 kW wind turbine, 2 units of deep cycle batteries (12V each/200Ah) and 1 unit of 1600 W Inverter. The prototype of the solar - wind hybrid power system based on the optimized components met the load demand for the basic appliances in the office. The results can be expanded to cover the entire department and the templates so obtained can be used generally within the University Community.

Design of support vector machine controller for hybrid power system automatic generation control

ABSTRACT This paper describes an online adaptive tuning methodology for Automatic Generation Control (AGC) of grid-connected wind-diesel hybrid power systems using the Support Vector Machine (SVM) controller. Using the Simulink design optimization tool/MATLAB, an optimized PID controller is first designed. To acquire system uncertainty, the SVM controller is trained using the input-output data set of an optimized PID controller obtained by varying the system nominal parameters by 40%. Simulations are carried out for conventional power generating units of various control areas integrated with hybrid wind-diesel power system. Outcomes are presented in the form of frequency aberration response, deviation in tie-line power exchange, and variation in mechanical power, and the efficacy of the proposed controller is presented in view of settling time, undershoot and overshoot. The impact of the hybrid power system on the thermal generating system is noted, and the usefulness of the developed SVM controller in keeping frequency and tie-line power exchange deviations within the stipulated limits is explored. The proposed SVM controller diminishes the settling time of frequency deviation response from 19.24 seconds to 14.36 seconds, and the undershoot and overshoots are reduced from 4.42% to 2.83% and 0.85% to 0.28%, respectively, for a three area three machine power structure. Further, the stability of the power systems under study is studied using bode-plot analysis with the designed controllers. As a result, the results indicated the robustness of the proposed SVM controller in minimizing system frequency and tie-line power variations caused by generation and load mismatch, as well as enhancing system stability.

A simulation study of solar wind hybrid power system

The global power shortages and pollution can be efficiently overcome by using renewable resources. But the continuous use of these sustainable resources is not very easy because of probability of availability and disturbances associated. The present work is based on a multiple renewable energy assets such as the sun and wind. In the proposed paper, the combination of a solar-powered and a wind-powered half-breed structure is studied and simulated in MATLAB software. The proposed work also validates the fact that a hybrid combination of multiple resource provide more reliable and economic feasible solutions than a single sun-based or a single wind based power unit. The proposed Simulink model also examined the management of active and reactive power profiles of the system.

Intelligent reactive power control of a renewable integrated hybrid energy system model using static synchronous compensators and soft computing techniques

Modern power system faces a severe problem of instability, largely due to inconsistent reactive power. It causes damage to the power grid within a few milliseconds. Therefore, proper management of reactive power under disturbing situations plays a key role in its safe operation. Devices such as flexible alternating current transmission systems (FACTS) accurately manage the system’s reactive power in accordance with the load demand. In this study, a new reactive power control strategy is employed for optimization of the reactive power along with the stability improvement of the system under different small perturbed conditions. Therefore, this study focuses on controlling the reactive power for an isolated wind-diesel hybrid power system model (WDHPSM) with the aid of a static synchronous compensator (STATCOM) together with the use of an integral minus proportional derivative (IPD) controller keeping a derivative-based filter (IPDF) as a secondary controller for better utilization of its purpose. The obtained results are compared when the no-control strategy is applied in the model. Another comparison has been done between the multiple applied soft computing techniques (oppositional harmonic search, ant lion optimization, binary-coded genetic algorithm, and symbiosis organisms search) that optimize the parameters of the controller of WDHPSM.

Integration of Small Modular Reactors Into Renewable Energy-Based Standalone Microgrids: An Energy Management Perspective

The environmental impact of human activities has become a significant consideration when making energy infrastructure decisions. To reduce energy poverty worldwide, there is growing interest in providing electricity in an environmentally sustainable way that minimizes greenhouse gas emissions. The same applies to the energy supply for off-grid industrial activities, such as mining projects and remote communities. These applications have traditionally been served by diesel generators, and more recently by wind-diesel hybrid power systems. Diesel and fuel oils are notorious for the high cost of transportation to remote sites, and for emissions of particulate pollution and greenhouse gasses. Such emissions can profoundly impact the environment in comparison to other types of power generation.

Effects of sizing on battery life and generation cost in PV–wind battery hybrid systems

Battery energy storage system (BESS) is a crucial part of standalone renewable hybrid power systems. Dynamic battery degradation analysis and life prediction are essential for better techno-economic estimation of standalone PV–wind battery hybrid power systems. With this viewpoint, this paper aims to study battery degradation using a physics-based pseudo-two-dimensional (P2D) thermal battery model integrated with renewable PV–wind hybrid power systems and investigates the impact of BESS size variation on its degradation and its effect on the energy generation costs A power management and control strategy is developed to ensure continuous power flow with two regulation modes; (a) maximum power point tracking and (b) controlled power generation. Yearly real-world load data, operating, and ambient conditions are used to study five different percentage mixes of PV and wind power generation scenarios. For example, a mix of 70% PV-30% wind, 350 kWh BESS is needed (base case) based on the demand. The yearly degradation rate for this case is calculated to be 3.80%. The degradation rates vary from 3.80 to 2.33% per year for every 10% increment in the BESS size from the base case. Performing a techno-economic analysis reveals that the least energy generation cost is achieved when increasing the BESS size by 20%. This increases BESS life from 5.3 years to 7.3 years and reduces the generation cost from 35.19 ₹ kWh−1 (0.482 $ kWh−1) to 34.34 ₹ kWh−1 (0.470 $ kWh−1). These results provide essential insights to analyse the impact of BESS sizing on degradation and energy generation cost in a standalone PV–wind battery hybrid power system framework. The oversized BESS provides extended life and reduces the energy generation cost for a standalone PV–wind–battery hybrid power system.

Adaptive robust control design to enhance smart grid power system stabilization using wind characteristics in Indonesia

<span lang="EN-US">This paper is interested to study power system stability in smart grid power system using wind characteristic in south of Yogyakarta, Indonesia. To overcome the intermittent of wind characteristics, this paper presents adaptive robust control design to enhance power system stabilization. The online identification system is used in this research, which updated whenever the estimated model mismatch exceeds predetermined bounds. Then genetic algorithm (GA) is applied to re-tune parameters controller based on the estimated model. The structure of controller is proportional integral (PI) controller due to the most applicable in industry, simple structure, low cost and high reliability. Robustness of controller is guaranteed by taking system uncertainties into consideration. The performance of the proposed controller has been carried out in a hybrid wind-diesel power system in comparison with previous work controller. Simulation results confirm that damping effect of the proposed controllers are much better that of the conventional controllers against various operating.</span>

Complex dual-tree wavelet transform and unified power management based control architecture for hybrid wind power system

This study proposes a complex dual-tree wavelet transform (CDTWT) based control technique for a combined sensitive load, battery, and hybrid wind power system (HWPS) to improve the power quality (PQ). To make the system hybrid both DC-grid and AC-grid are connected through two parallel inverters and to circumvent the sudden power demand, it is connected to the main grid. The CDTWT based control technique easily decomposes the non-linear load current into different frequency levels and extracts the fundamental line frequency component for the computation of the actual active current component. In addition to that, to improve the power reliability (PR) and generate the desired current signals, a novel centralized control and power management (CCPM) approach is proposed. The generated reference current is used to coordinate both of the parallel inverters for offering synchronize power flow, regulate the voltage and frequency and offer regardless of switching operation, at both grid supporting and islanding conditions. The MATLAB/Simulink software is used to develop and test the proposed HWPS at different working modes as the failure of one inverter and the sudden addition of two wind turbines at grid-supporting mode and to show battery functionalities at islanding modes of operation. To justify the necessity of the proposed controller, the total harmonic distortion (THD), stability, and advancement of CDTWT results are also presented at different operating modes. From the test results, it is found that with the presence of 20.06% non-linear load current, the overall improvement percentage of inverter and grid current is 96%-97% and 99% respectively. In addition to that, the proposed technique takes only 0.04 s-0.05 s transition time. The above percentages are well within the prescribed limit of IEEE-1541 and IEEE 1547–2018 and are suggested for real-time complex microgrid operation.

Solar PV-Wind System Integration with Power Grid System

This paper describes a photovoltaic (PV) and wind hybrid power system that is equipped with a Diode Clamped Multi-Level Inverter and LC filter for the generation of renewable energy. Due to their environmental friendliness and availability, wind and solar energy are ideal for hybrid systems in India. Due to fluctuations in the output voltage, equipment that require a consistent supply will be damaged by hybrid power systems that are completely dependent upon intermittent renewable energy sources. Matlab Simulink is used to create a model of the hybrid system using a Diode Clamped Multi-Level Inverter and an LC filter. Before merging a DC voltage hybrid system with the main grid of the power system, blocks such as the wind model, solar model, Diode Clamped Multi-Level Inverter, and LC filter are developed independently.... The input parameters for the project simulation include different irradiance values and varied wind speeds. Initially, a DC voltage hybrid system with the main grid of power system is constructed separately, taking into account the characteristics of the wind and photovoltaic models developed, as well as the simulation results for hybrid systems with and without Diode Clamped Multi-Level Inverters and LC filters. The input parameters for the project simulation include different irradiance values and varied wind speeds. Present are the wind and photovoltaic model characteristics, as well as simulation results for a hybrid system with and without a Diode Clamped Multi-Level Inverter and LC Filter. The results suggest that hybrid systems are more reliable in terms of generating output voltage than solo systems in this study. As well as this, the hybrid system's Diode Clamped Multi-Level Inverter and LC Filter can reduce output voltage fluctuations.

Application of Posicast controller with SVC in wind-diesel hybrid power system model

Posicast controller is used to damp out oscillations of power system by changing excitation of the reference signal. The main purpose of this controller is to reduce the overshoot and the rising time of the transient voltage response of power system. In the present work, Posicast controller and static VAR controller (SVC) have been used to enhance the stability under any form of small disturbance of a wind-diesel hybrid power system (WDHPS) model. Stability of the hybrid model is, mainly, affected by the active and the reactive power unbalance. In this paper, reactive power unbalance has been carried out and it may be handled by using these two controllers. In the studied WDHPS model, a power system stabilizer (mainly, PSS3B) is also included along with the Posicast with SVC controller and performance of the hybrid model is investigated with the help of different soft computing techniques. Soft computing techniques are, basically, used to adjust the different parameters of the studied WDHPS based model for smooth and healthy operations of the hybrid model. The employed technique establishes better performance of the studied WDHPS based model in terms of superior dynamic reactive power compensation offered in real-time.

The stability control for isolated wind‐diesel power system based on the cross coupling effect model

In the isolated wind-diesel hybrid power system, the system voltage and frequency may be affected simultaneously by the fluctuated wind turbine output power and variable load, which can make the system crash in extreme cases without control strategy. Therefore, in order to reduce the voltage and frequency deviation caused by system power fluctuation, both the battery and super twisting algorithm sliding mode state observer (STATCOM) are equipped to adjust the active power and reactive power for load power demand in the isolated small-scale power system. Then, the system mathematical model is established which considers the cross-coupling effect exist in the small-scale power system. In order to improve the control effect of battery and STATCOM, the unified control strategy is designed for battery and STATCOM by using the super twisting sliding mode state observer and the adaptive sliding mode controller according to the constructed cross-coupling effect model. Furthermore, the parameters of controller are further optimized by using the fuzzy method. Finally, the simulation experiments are performed by the real-time digital simulator to validate the effectiveness of the proposed control strategy under different operation points.

The frequency-voltage stability control for isolated wind-diesel hybrid power system

In order to assure the stability of isolated wind-diesel hybrid power system under load fluctuation and wind power disturbance, the frequency-voltage integrated control strategy is proposed to adjust the stability output of active and reactive power. Firstly, the whole model is established for the isolated hybrid power system including synchronous generator, battery and STATCOM. Furthermore, the improved sliding mode (SM) observer is constructed to estimate the immeasurable state variable for the controller design. Then, the adaptive sliding mode voltage and frequency controller is designed by using the cloud model method, which can optimize the parameters for improving the accuracy and intelligence of the proposed controller. Finally, the real time digital simulator (RTDS) and MATLAB simulation results under different operations can verify the effectiveness of the proposed control strategy for the hybrid system.