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With increasing demand in energy, efficiency, reliability, and resiliency in the power systems, integration of distributed generation (DG) or renewable energy sources in the local distribution system is trending nowadays. The power system optimization in distribution networks plays a prominent role in planning reliable supply to the users. This paper presents a meta-heuristic approach to improve the system performance by considering: a) voltage profile improvement, b) minimize the active power loss, and c) overall operation cost as the objective functions of the distribution system reconfiguration (DSR). Modified Newton Raphson (MNR) is used for a load flow analysis of the 33 bus balanced test system and 25 bus unbalanced distribution system. To study the performance of the system objective functions, three different scenarios are considered: i) with DG integrated, ii) with DSR performed, and iii) DG placed along with DSR. These scenarios are compared with the base system configuration parameters along with convergence comparison of harmony search algorithm (HAS) and particle swarm optimization (PSO) with firefly algorithm (FFA) of the distribution systems. [ABSTRACT FROM AUTHOR]

In this paper, the performance and reliability of the hybrid microgrid system is analyzed with the two different configurations where multiple distributed energy sources supplied the power to the loads through centralized inverter and parallel inverter. The power quality, power sharing, power exchange and voltage and frequency drop parameters are evaluated by applying 1.1 kVA load on the centralized and parallel inverter hybrid systems with LL and LLG faults. The hysteresis current controller in the centralized inverter hybrid system is assuring the accurate power exchange between the grid and hybrid system during abnormal conditions. The droop controller in parallel inverter hybrid system is effectively sharing the load among the inverters during normal and abnormal conditions. The comparative analysis of these energy systems is made based on control aspects, power quality, reliability and economics. [ABSTRACT FROM AUTHOR]

Research on Self –excited induction generator (SEIG) brings a lot of attentions in the last three decades as a promising solution in distributed generation systems with low cost investment. There are two important fixations to attend in the operation of SEIG based systems, a) excitation and b) voltage regulation. Many procedures are reported regarding selection of excitation capacitance in the literature, based on state-state analysis, dynamic modeling, empirical formulas and machine parameters which involve various levels of complexity in findings. Moreover, the voltage regulation is the main challenge in implementation of SEIG based isolated systems. To address this problem, many power electronic-based schemes are proposed in the literature and but these solutions have few demerits importantly that additional cost of equipment and troubles due to failure of protection schemes. In particular, the installation of SEIG takes place at small scale in kW range in remote/rural communities which should not face such shortcomings. Further in case of off-grid systems, the maximum loading is fixed based on connected rating of the generator. This paper presents the various methods to find excitation capacitance and illustrates an experimental investigation on different possible reactive power compensation methods of delta connected SEIG and aimed to identify a simple method for terminal voltage control without power electronics. In this experimental work, the prime-mover of the generator is a constant speed turbine, which is the emulation of a micro/pico hydro turbine. From the results, it is found that a simple delta connected excitation and delta configured reactive power compensation limits voltage regulation within ±6% while maintaining the frequency of ±1%, which make feasible of the operation successfully in remote electrification systems. [ABSTRACT FROM AUTHOR]

This paper proposes a security-constrained single and multi-objective optimization (MOO) based realistic security constrained-reactive power market clearing (SC-RPMC) mechanism in a hybrid power system by integrating the wind energy generators (WEGs) along with traditional thermal generating stations. Pre-contingency and post-contingency reactive power price clearing plans are developed. Different objective functions considered are the reactive power cost (RPC) minimization, voltage stability enhancement index (VSEI) minimization, system loss minimization (SLM), and the amount of load served maximization (LSM). These objectives of the SC-RPMC problem are solved in a single objective as well as multi-objective manner. The choice of objective functions for the MOO model depends on the load model and the operating condition of the system. For example, the SLM is an important objective function for the constant power load model, whereas the LSM is for the voltage-dependent/variable load model. The VSEI objective should be used only in near-critical loading conditions. The SLM/LSM objective is for all other operating conditions. The reason for using multiple objectives instead of a single objective and the rationale for the choice of the appropriate objectives for a given situation is explained. In this work, the teaching learning-based optimization (TLBO) algorithm is used for solving the proposed single objective-based SC-RPMC problem, and a non-dominated sorting-based TLBO technique is used for solving the multi-objective-based SC-RPMC problem. The fuzzy decision-making approach is applied for extracting the best-compromised solution. The validity and efficiency of the proposed market-clearing approach have been tested on IEEE 30 bus network. [ABSTRACT FROM AUTHOR]

Power sharing between distributed energy resources (DERs) is being a significant challenge in the stand-alone microgrid system as it must be ensured to supply good power quality supply for end-users. Due to the variable power generation, particularly from solar and wind energy resources, the energy storage systems are essential to store the excess energy and supply the energy during an emergency in the absence of a grid connection. This option ensures optimal energy management and therefore improves the reliability of the system. But at the same time, the maintenance, life span and cost are the drawbacks of battery systems, and therefore, some researchers are working on minimizing dependency of battery by storing energy in other different forms. In this paper, the following three alternative energy routes are proposed to utilize the excess energy for (a) water pumping system, (b) battery storage system and (c) dump load. Based on the variation of end-user consumption, the above three options are used to attain power balancing in the microgrid. In this study, the direct on line starter, DC–DC converter and electronic load controller control the water pumping, battery storage and dump load, respectively. To enhance the power quality, a modified RMS voltage-based droop controller is presented for operating two DER fed parallel inverters, as it assures stable operation and exhibits the following desired characteristics: (1) accurate real and reactive power sharing, and (2) voltage and frequency regulation. Furthermore, the stability analysis is carried out on the proposed system to test the effectiveness. [ABSTRACT FROM AUTHOR]

Emerging technologies in an electric vehicle (EV) had greater advancement in the control, batteries and electric motors design. But safety and reliability are the major concerns when the consumer is dealing with a high voltage conductor for charging. The recurring of plugging in the switch for charging is an undeniable disadvantage. Therefore, to eliminate the human intervention in charging of a battery, wireless power transfer (WPT) will be the most effective methodology to charge the EV. This paper aims at building the prototype of 1 kW inductive WPT with high frequency supply with power converters. To design this system, standards of EV charging systems are incorporated; also, a suitable coil structure is identified for the given EV model as per the standards. The mismatch or misalignment of the receiver coil, air gap between receiver–transmitter (i.e., proximity) and compensation techniques are considered in this work. Efficient design of power electronic converter is implemented for both transmitter and receiver side. Both coil design model and the power electronic system are integrated to test the performance of proposed WPT technology. [ABSTRACT FROM AUTHOR]

The objective of this paper is to improve the voltage profile of the grid in pertinence to grid due to power injection from distributed solar photovoltaic (PV) arrays. Weak grids are modeled as worldwide adaptation of net metering, transactive energy systems, and the possibility of further deterioration of power quality with higher grid penetration. In this paper, a solar PV integrated weak distribution grid modelled as the PV arrays being frequently connected in rural areas, due to various reasons like cheap real estate and lack of accessibility. In this paper, three case studies of PV generation are simulated, i.e., scheduled solar PV generation less than load requirement, PV generation equal to load requirement, and PV generation more than load requirement, by considering the daily solar irradiation and load demand profiles of a residential area under study. [ABSTRACT FROM AUTHOR]

• Proposed a cost-effective two-stage distributed energy management system for microgrid operation, addressing challenges related to renewable energy integration, distributed generators, and electric vehicles (EVs). • Utilized EV demand aggregation to reduce demand on battery storage systems and diesel generators, prolonging battery life and minimizing reliance on expensive and polluting generators for secondary frequency regulation. • Introduced an adjusted consensus ADMM (ACADMM) algorithm to handle energy management problems during communication delays, achieving faster convergence and robust solutions. • Implemented a Stackelberg game framework for designing pricing at EV charging stations, incentivizing customers to participate in secondary frequency control and maximizing cumulative profit for the EV aggregator (EVA). • Proposed an adaptive phase switching algorithm to ensure voltage phase balancing at charging stations, addressing voltage imbalances caused by varying power demands and enhancing overall system performance. Effective dispatch of ancillary services is a significant challenge for microgrids that incorporate renewable energy (RE), distributed generators (DG), and electric vehicles (EVs), due to uncertainties and communication delays during their operation. The secondary frequency regulation becomes a key task to restore the frequency to the set point through a load control strategy. This paper presents a cost-effective two-stage distributed energy management system (EMS) for microgrid operation to reduce reliance on battery storage systems and diesel generators, prolonging battery life and minimizing the use of expensive and polluting generators for secondary frequency regulation. Communication delays are addressed using an adjusted consensus ADMM algorithm, ensuring convergence. Additionally, a Stackelberg game framework is employed to design pricing at EV charging stations and incentivize customers to participate in secondary frequency control. An adaptive phase switching algorithm for phase switches is also proposed to ensure voltage phase balancing. Simulation results demonstrate an 8.98% reduction in cost deviation across stages, with a $234.46 profit by the EV aggregator during the intraday stage, considering secondary frequency regulation. The proposed approach offers a promising solution for efficient microgrid operation and effective integration of renewable energy and electric vehicles. [ABSTRACT FROM AUTHOR]

Due to the surge in load demand, the scarcity of fossil fuels, and increased concerns about global climate change, researchers have found distributed energy resources (DERs) to be alternatives to large conventional power generation. However, a drastic increase in the installation of distributed generation (DGs) increases the variability, volatility, and poor power quality issues in the microgrid (MG). To avoid prolonged outages in the distribution system, the implementation of energy management strategies (EMS) is necessary within the MG environment. The loads are allowed to participate in the energy management (EM) so as to reduce or shift their demands to non-peak hours such that the maximum peak in the system gets reduced. Therefore, this article addresses the complication of solutions, merits, and demerits that may be encountered in today's power system and encompassed with demand response (DR) and its impacts in reducing the installation cost, the capital cost of DGs, and total electricity tariff. Moreover, the paper focuses on various communication technologies, load clustering techniques, and sizing methodologies presented. [ABSTRACT FROM AUTHOR]

To sustain the complexity of growing demand, the conventional grid (CG) is incorporated with communication technology like advanced metering with sensors, demand response (DR), energy storage systems (ESS), and inclusion of electric vehicles (EV). In order to maintain local area energy balance and reliability, microgrids (MG) are proposed. Microgrids are low or medium voltage distribution systems with a resilient operation, that control the exchange of power between the main grid, locally distributed generators (DGs), and consumers using intelligent energy management techniques. This paper gives a brief introduction to microgrids, their operations, and further, a review of different energy management approaches. In a microgrid control strategy, an energy management system (EMS) is the key component to maintain the balance between energy resources (CG, DG, ESS, and EVs) and loads available while contributing the profit to utility. This article classifies the methodologies used for EMS based on the structure, control, and technique used. The untapped areas which have scope for investigation are also mentioned. [ABSTRACT FROM AUTHOR]

This paper presents stability enhancement of a test system that is connected with a Wind Farm (WF) by using Power System Stabilizer (PSS) for Synchronous Generator (SG) and Power Oscillation Damper (POD) for Static Var Compensator (SVC). This paper also proposes a coordination mechanism for the controller to effectively damp out the oscillations and make the power system more stable by considering the uncertainties. The uncertainty is considered as wind speed variation and wind power penetration and different locations. The Particle Swarm Optimization (PSO) is used to overcome the controller parameter tuning drawbacks and controller coordination. The SG rotor speed deviation is selected as an objective function with various constraints for PSO. The transient stability analysis is carried out by considering large disturbance that is a three-phase fault. The nonlinear dynamic simulation results are obtained by integrating WF and SG replacement with the same rating WF. Evaluation and analysis are performed for various cases and different combination of without and with controllers. From the simulation results, it is noticed that oscillations in the system are minimized, and stability is enhanced at the maximum level. It also observed that the capability of SG and DFIG under three-phase fault is intensified by using PSO for optimized coordinated controller parameters. The robustness and effectiveness of the proposed approaches are evaluated on the IEEE-11 bus test system. [ABSTRACT FROM AUTHOR]