Grid-connected Renewable Energy Research Articles

A Review of Renewable Energy and Power System Integration

Wind and solar energy are two examples of the renewable energy that nations around the world are accelerating their development of in response to global climate change and energy scarcity. However, current power networks face new difficulties as a result of these energy sources' volatility and intermittency. Based on the existing literature and data, this article reviews the latest research advances in the integration of renewable energy sources (such as solar and wind) with conventional power systems. The paper discusses the main technical challenges faced in the integration process, including intermittency, stability and other issues. At the same time, this paper discusses the development of demand response, load management, machine learning, energy storage technology and smart grid technology, of which smart grid technology is the main content of this article review. The purpose of this paper is to summarize the existing smart grid technology, explain the help of smart grid for renewable energy grid connection, and provide a reference direction for future research. Finally, according to the existing policies, the paper looks forward to the future and believes that the share of renewable energy in the future grid will be increasing.

Controlled Non-Dominated Sorting Genetic Algorithms for Multi-Objective Optimal Design of Standalone and Grid-Connected Renewable Energy Systems in Integrated Energy Sectors

Controlled Non-Dominated Sorting Genetic Algorithms for Multi-Objective Optimal Design of Standalone and Grid-Connected Renewable Energy Systems in Integrated Energy Sectors

Techno-economic utilization of hybrid optimized gravity-supercapacitor energy-storage system for enriching the stability of grid-connected renewable energy sources

Techno-economic utilization of hybrid optimized gravity-supercapacitor energy-storage system for enriching the stability of grid-connected renewable energy sources

Optimization of grid-connected hybrid renewable energy system for the educational institutes in Pakistan

To foster resilient energy transition systems, the deployment of renewable energy sources is potentially helpful in the acceleration towards sustainable, reliable, and diversified solutions. In this feasibility study, aims to pursuit the best optimal solution for renewable energy resources, integrated into the local university's energy mix, to meet the electrical load demand of 8500 kWhr/day and a peak load of 815 kW. A model of a hybrid grid-connected renewable energy (PV/Biomass/Hydel/Diesel generator/Grid) system was implemented in HOMER software, to obtain the most efficient and cost-effective hybrid energy generation. The outcomes of the simulation seem more viable based on sensitivity analysis, as the cost of energy (COE) for an energy system with a hybrid combination is 0.13.$/kWh, meanwhile energy price with the grid system is 0.18 $/kWh. According to the HOMER analysis, a hybrid grid-connected PV/biomass/hydro system demonstrates both technological feasibility and economic viability, meanwhile it will also save 1575 tons of CO2 per year. Therefore, this proposed hybrid energy system, a step towards sustainable development, can be applied at institutional levels, especially in developing countries.

Improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy

The flexible DC transmission project of renewable energy has become an inevitable development trend for large-scale renewable energy grid connection. Its two-terminal weak feed AC system is often composed of 100 % power electronic power equipment. The fault control strategy is used at both ends of the line to change the fault current characteristics, leading to a decrease in the performance of traditional differential protection. Based on analyzing the adaptability of current differential protection in the two-terminal weak feed AC system under traditional control strategy (TCS), this paper proposed an improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy. Firstly, the fault characteristics of the two terminal weak feed AC systems are analyzed. On this basis, the adaptability of differential protection under TCS is analyzed, and the quantization function that can quantify the operation performance of differential protection is given. Secondly, based on the problem of the traditional negative sequence control strategy, an improved control strategy is introduced and the operation performance of differential protection under the improved control strategy is studied. Finally, an improved differential protection scheme based on the change of current amplitude is proposed. Simulation results show that the proposed protection scheme can resist higher fault impedance(300 Ω) and noise interference(25 dB). In addition, the proposed differential protection scheme is suitable for the protection requirements of the two terminal weak feed AC systems in different scenarios and has higher sensitivity.

The role of hybrid hydrogen-battery storage in a grid-connected renewable energy microgrid considering time-of-use electricity tariffs

Hybrid hydrogen (H2)-battery BT integrated microgrid has gained significant interest lately as a key element for achieving a zero-emission future, thanks to its wide range of applications. The energy management strategy (EMS) of the H2- BT storage-based microgrid is critical for ensuring efficient and cost-effective electricity generation by controlling the operating point of the storage systems to achieve economic and operational benefits. This paper presents an optimal energy management and sizing strategy for a hybrid H2-BT storage-based grid-connected microgrid, considering two scenarios of Time-of-Use (ToU) electricity tariffs. The uniqueness of this study lies in its improvement of microgrid effectiveness through the optimization of component size and EMS. Among the two scenarios, the “Time of Use-Flat” scenario is more cost-effective and the best option. This conclusion is based on the results which indicate that LSC-SSA method achieved the lowest Annual System Cost (ASC) of $544,818 and the lowest Levelized Cost of Energy (LCOE) of $0.273 in this scenario. These metrics are better compared to the “Flat-Time of Use” scenario, where the LSC-SSA method achieved an ASC of $552,773 and an LCOE of $0.277. Therefore, the “Time of Use-Flat” scenario provides greater cost-effectiveness for the hybrid H2-BT integrated microgrid.

Does the incentive policy for renewable energy grid connection affect the technical efficiency of power grid companies? Empirical analysis based on China and Japan

The widespread adoption of renewable energy sources, which are characterized by intermittency, uncertainty, and uneven geographical distribution, has significantly influenced power grid operating efficiency. This study employs the meta-frontier model to assess the impact of varying degrees of renewable energy development in China and Japan from 2008 to 2022 on the efficiency of 40 power grid companies. The research reveals that the rapid increase in renewable energy generation has posed significant challenges to grid management, leading to a decline in grid company technical efficiency. Despite implementing entirely different renewable energy incentive policies, both China and Japan have encountered a detrimental effect on the efficiency of their power grids. However, over time, the adverse impact of renewable energy on grid efficiency has shown signs of attenuation. This positive trend is partly attributable to measures such as enhanced infrastructure development and improved technical standards, which have effectively mitigated the negative effects of renewable energy integration on grid operations. Based on these findings, the study emphasizes the importance of bolstering grid infrastructure and fostering technological innovations to minimize the disruptive effects of renewable energy on grid efficiency.

Exploring the dynamics of socio-technical transitions: Advancing grid-connected wind and solar energy adoption in Nigeria

Globally, countries are transitioning their national electricity grid system to meet the obligations of the Paris Agreement. National grid-connected renewable electricity provides an opportunity to reduce greenhouse gas emissions. Specifically, in a developing country like Nigeria, renewable energies such as solar and wind power can play a critical role not only in transitioning away from fossil-fuel based electricity systems but also to address prevalent energy security challenges, electricity supply deficit and gaps in energy access. Policies, plans, and strategies to ensure grid-connected renewable energy have been put in place, but these measures have proved ineffective. Likewise, there are limited studies that investigate these transition problems, including drivers and enablers from a developing country perspective. This research fills that gap in knowledge by investigating these transition dynamics through a qualitative approach applying the multi-level perspective framework. Thirty-one (31) key energy and non-energy actors were interviewed, and the transcripts thematically analysed. Findings indicate that there is prospect for Nigeria to transform its electricity system. However, there are major deterrents including institutional, infrastructural, incumbent electricity system instability and economic barriers. The paper highlights that there is a level of regime stability/instability that will enable renewable energy development. In addition, practical and policy insights are offered to overcome identified challenges towards accelerating electricity system transformation. Future studies should also explore the degree of instability, stability and change in developing country settings necessary for energy transition to occur. Finally, this paper advances debates in energy transition and socio-technical system studies.

Power Quality Enrichment and Power Management using an Adaptive Control Scheme in Microgrid System

This article proposes an ANFIS-based control scheme for improved power quality and power management that will provide optimal and sustainable energy in a grid-connected renewable energy system. The system consists of a wind energy conversion system (WECS), a photo voltaic system (PVS), and a battery energy storage system (BESS). To increase the PVS's and WECS output powers, a unique control approach is suggested in this paper. The adaptive Neuro-Fuzzy Inference System (ANFIS) controller is incorporated into the proposed controller to generate three-phase reference current signals for harmonic elimination in the system during system dynamic conditions. The proposed control technique can work under voltage quality problems such as voltage sag, voltage swell, neutral currents, and reactive power. Renewable energy sources (PV and Wind) are interfaced to improve the DC-link overall performance by minimizing short-term and long-term voltage problems. The proposed controller regulates the energy flows between the renewable energy sources to the end users with a unity power factor. A supervisory control scheme is implemented for optimal power management in the system. Based on the load requirement, and how the renewable, battery, and grid sources are sharing the power, a detailed analysis is given in the paper. Simulation results from the MATLAB/Simulink platform under several test conditions at the grid side and load side illustrate the efficacy of the proposed control mechanisms in the environment of power optimization and energy management. The comparative analysis is performed to show the efficacy of the proposed system. Finally, the proposed system is validated and the THD content of the grid currents is found good.

Optimal rule-based energy management and sizing of a grid-connected renewable energy microgrid with hybrid storage using Levy Flight Algorithm

The study addresses the integration of hybrid hydrogen (H2) and battery (BT) energy storage systems into a renewable energy microgrid comprising solar photovoltaic (PV) and wind turbine (WT) systems. The research problem focuses on improving the effectiveness and computational efficiency of energy management systems (EMS) while ensuring high system reliability. Despite the existing optimization methods for hybrid microgrids, challenges remain in optimizing energy storage and capacity planning in grid-connected microgrids. To solve this, we propose the use of the Levy Flight Algorithm (LFA) to optimize the capacities of PV, WT, H2 tanks, electrolyzers (EL), fuel cells (FC), and BT, which presents a complex nonlinear optimization challenge. The novelty of this study lies in integrating the LFA with a rule-based EMS, enhancing system reliability and efficiency. The proposed approach significantly reduces the annualized system cost (ASC) and the levelized cost of energy (LCOE). The result demonstrate that the LFA outperforms methods like the Salp Swarm Algorithm (SSA), Particle Swarm Optimization (PSO), Grey Wolf Optimization (GWO) and Genetic Algorithm (GA), yielding cost savings of $3,309, $5,297, $4,484, and $5,129 respectively. The LFA achieves the lowest LCOE at $0.275/kWh, compared to $0.278/kWh with SSA, $0.289/kWh with GA, $0.280/kWh with PSO and $0.283/kWh with GWO. This research contributes to the broader scientific community by providing a more efficient approach to optimizing renewable energy microgrids with hybrid storage systems, thus promoting eco-friendly and cost-effective energy solutions. The proposed system design offers a pathway to future energy systems with high renewable integration, especially as technology advances and costs continue to decrease.

Transient behavior of pumped storage-wind hybrid power system under grid-connected operation condition

The large-scale grid connection of renewable energy represented by wind power threatens the safe and stable operation of electric system. The vigorous development pumped storage power station (PSPS) is a global consensus to support the grid-connected of renewable energy. This paper investigates the transient behavior of pumped storage-wind (PSW) hybrid power system under grid-connected operation condition (GCOC). Firstly, a model of PSW hybrid power system under GCOC is constructed. The stable domain is determined according to Hopf bifurcation theory. The influence of system parameters on the stability of PSW hybrid power system under GCOC is analyzed. A synergetic control strategy is designed to improve the dynamic performance of the system. Then, the mechanism of multi-time-scale dynamic response is revealed. Finally, the transient behavior of PSPS under different application scenarios and the interaction between PSPS and wind power station (WPS) are studied. The results show that the stability of PSW hybrid power system under GCOC can be judged by stable domain. The designed synergetic control strategy can improve the dynamic performance of the system. The dynamic response is composed of three oscillations with different frequencies, namely, mass oscillation at low frequency, water hammer oscillation at medium frequency, and electrical oscillation at high frequency. The principal oscillation is caused by water hammer. The interaction between PSPS and WPS has a significant effect on the transient behavior. By adjusting the interaction between PSPS and WPS, the system can absorb more wind power while ensuring safe and stable operation, which can increase profits and avoid unnecessary operation oscillations. The analytical methods and results presented in this paper are of great significance for improving the ability of power grid to accept renewable energy.

Strategic optimization of PV integrated fuel cell systems for energy surplus utilization in grid failure scenarios

Effective energy management in grid-connected renewable energy systems is essential for achieving cost-efficiency and reliability. This work presents a versatile control technique to tackle power system difficulties in grid-connected and grid-failure modes. The concept employs a digital iterative approach to optimize the operation of a DC-DC converter, guaranteeing the attainment of maximum power output and stability. During a grid breakdown, the system injects carefully adjusted active power into the grid to ensure that voltage and current levels are maintained at appropriate levels, hence preventing overloading. The proposed strategy exhibits a 99% enhancement in system responsiveness and a 96% decrease in overshoot when compared to conventional methods, thus substantiating its efficacy in practical scenarios.

A comprehensive study on energy management, sensitivity analysis, and inertia compliance of feed-in tariff in IEEE bus systems with grid-connected renewable energy sources

The need to incorporate renewable energy generators (REGs) into the electrical grid has become increasingly crucial due to the push for a more sustainable environment. This study advocates an innovative strategy for optimizing inertia-integrated generation and transmission expansion planning (GTEP) to implement feed-in tariffs (FiT). The application of the GAMS CPLEX solver to the model, which tested on an IEEE 6/IEEE 16 system, reveals that using FiT results in a 12.1 % drop in system cost ($599 million to $526 million) and a 7.91 % rise in total system inertia. Sensitivity analysis highlights the correlation between increased REG integration and FiT payment reduction at 50 % penetration. The model outperforms soft computing optimization techniques, showcasing rapid convergence and computational efficiency. The proposed model's validated superiority in rapid convergence and computational efficiency is demonstrated by comparing its results with those obtained from other soft computing optimization techniques.

Implementing Tri-Brid Energy Systems for Renewable Integration in Southern Alberta, Canada

The steep decline in the price of wind and solar photovoltaics provides a possibility to decarbonize electricity deeply and affordably. This study uses the HOMER Pro energy modeling tool to model an optimized grid-connected renewable energy system for a community in southern Alberta, Canada. The study’s goal is to identify the best renewable energy technology combinations that can provide electricity at the lowest levelized cost of energy (LCOE) and has lower greenhouse gas emissions as compared to the electricity produced by traditional fossil fuel. Gleichen is a small town in southern Alberta that is close to numerous commercial wind and solar projects given the region’s high quality renewable resources. “Tri-brid” systems consisting of wind turbines, solar photovoltaics, and battery energy storage systems (BESS) are considered and compared based on electricity prices, net present cost, and greenhouse gas emissions savings. This tri-brid system is connected to the grid to sell excess generated electricity or buy electricity when there is less or no availability of solar and wind energy. The tri-brid energy system has an estimated LCOE of 0.0705 CAD/kWh, which is competitive with the price of electricity generated by natural gas and coal, which is 0.127 CAD/kWh.

Control Strategies for Mitigating Power Quality Issues in Renewable Energy coordinated Microgrid - A Comprehensive Review

Abstract Renewable Energy technologies are becoming more and more common for generating electricity because they are environmentally friendly and can meet local electricity needs. They reduce network congestion and also lighten the load on conventional based power plants. Over the past few decades, grid-connected renewable energy systems have seen a rise in the significance of Power Quality issues, particularly as a result of the extensive usage of nonlinear electronics and the intermittent nature of these systems. With the emergence of power electronic converters through powerful control technology, renewable energy systems be interconnected to a large extent with the power grid or used as isolation systems in remote areas. Using additional competent control strategies can enhance not only improve the concert of these systems, but also caliber the quality of energy generated, distributed and used at the load side of Power System. Hence, this paper reviews various control strategies adopted for alleviation of power quality staples of renewable energy coordinated microgrid system and further recommendations are provided to solve power quality issues as future research.

Robust PWM control scheme for switched-capacitor MLI with leakage current suppression in grid-connected renewable energy application

Typically, parasitic capacitances exist between the ground and the solar panel terminals in grid-connected PV systems. These parasitic capacitances provide a path for a leakage current, which leads to significant safety concerns, observable and seriously hazardous harmonic orders aligned with the injected grid current, and significant safety difficulties. In this research, a robust PWM controlling method that used competently in reducing the level of the leakage current and improving the power quality of a switched-capacitor Multilevel Inverter. This technique creates developed reference signals from the main signal to generate the switching scheme for the converter circuit. Additionally, the suggested control strategy only works with a small number of carrier signals, resulting in a quick system response and a simpler controller algorithm. Likewise, this controlling approach offers a stable way to maintain a constant output voltage in the suggested converter by adjusting the switching capacitors' voltages, which is not possible with traditional control techniques. MATLAB/Simulink is used to simulate the outcomes for both the suggested control approach and the traditional Phase Disposition (PD) PWM control method whereas the leakage current component reduces to 25 % compared to the captured component with the PDPWM. The simulation and the practical results based on the dSPACE-1103 hardware are quite similar.

Energy Management Strategies of Grid Connected Renewable Source for EV Charging Station

The growing popularity of electric vehicles (EVs) has made the need for effective charging infrastructure necessary. Combining renewable energy sources with EV charging stations offers a viable way to lessen transportation's negative environmental effects and cut back on fossil fuel use. This study looks into different grid-connected renewable energy source energy management techniques for EV charging stations. This study aims to optimize energy utilization, lower operating costs, and improve the sustainability of EV charging infrastructure by utilizing renewable energy generation, such as solar and wind power, in conjunction with intelligent charging algorithms. The study examines the body of research, evaluates various energy-management strategies, and suggests creative solutions to the problems arising from incorporating renewable energy sources into EV charging stations. The report also addresses the possible advantages, practical issues, and financial effects of putting these strategies into practice. This research advances our understanding of energy management systems for grid-connected renewable sources in the context of EV charging infrastructure through thorough analysis and simulation studies.

Reasonable Energy-Abandonment Operation of a Combined Power Generation System with an Ultra-High Proportion of Renewable Energy

With large-scale grid-connected renewable energy, new power systems require more flexible and reliable energy storage power sources. Pumped storage stations play an important role in peak shaving, valley filling, and promoting renewable energy consumption. This paper presents the reasonable energy-abandonment operation of a combined power generation system (CPGS), in which a pumped storage station is the core control power, with an ultra-high proportion of renewable energy. Firstly, based on the seasonal characteristics of wind, solar, and load demand, typical days are selected through improved clustering analysis algorithms. Then, a daily optimal scheduling model for combined power generation systems (CPGS) is developed with the goals of economy, low-carbon, and stable operation. Finally, the correlation between the energy-abandonment rate and pumped storage station peak shaving and system optimization operation indicators is obtained by a reasonable energy-abandonment calculation method considering source-grid-load coordination. Taking the operation data of an energy base in the western region of China as an example, when the penetration rate of renewable energy is 60–70% in the future, the operating cost on the power side is greatly affected by the construction of the source side. When the system operates at a planned reasonable energy-abandonment rate of 2%, electricity regulation, load tracking, and daily operating costs all show better performance.

A Review of the Research on the Wide-Band Oscillation Analysis and Suppression of Renewable Energy Grid-Connected Systems

With the continuous expansion of the scale of power generated by grid-connected renewable energy, the form and operation characteristics of power grids have undergone significant changes, and the power electronic characteristics of power systems are prominent, resulting in the frequent occurrence of wide-band oscillation problems when renewable energy power generation equipment is connected to a power grid. Oscillation has the characteristics of nonlinearity and has an oscillation frequency ranging from a few hertz to several thousand hertz or more, which seriously threatens the stable operation of power grids. This paper summarizes the wide-band oscillation events that occur worldwide under the background of renewable energy access to power grids, classifies the wide-band oscillation events according to the distribution of oscillation frequency bands, and sorts out the characteristics of various oscillations. From the perspectives of the source side and network side, the existing oscillation suppression measures are classified and prospected.

Load Frequency Active Disturbance Rejection Control Based on Improved Particle Swarm Optimization

A load frequency control (LFC) system based on active disturbance rejection control (ADRC) is designed to solve the problem of frequency modulation caused by large-scale renewable energy grid connection. Traditional parameter-tuning methods are inefficient and often fail to achieve desired control outcomes. To overcome this, an improved Particle Swarm Optimization (PSO) algorithm is introduced, incorporating Levy flight and chaotic mapping. This enhanced algorithm combines the long step–length search capability of Levy flight with the rapid exploration of initial solution space using Tent chaotic mapping, enhancing PSO’s global search ability and addressing premature convergence issues. Simulation results demonstrate that the ADRC controller optimized by the improved algorithm exhibits greater robustness and smaller deviation compared to the original algorithm, showcasing its excellent control performance.