Fig 8 - uploaded by Shreyasi Som
Content may be subject to copyright.
![Benchmark LVAC interconnected islanded microgrid test-system [31]](profile/Shreyasi-Som-2/publication/368435546/figure/fig1/AS:11431281160113781@1684597623669/Benchmark-LVAC-interconnected-islanded-microgrid-test-system-31.png)
Benchmark LVAC interconnected islanded microgrid test-system [31]
Source publication
![Fig. 8. Benchmark LVAC interconnected islanded microgrid test-system [31]](profile/Shreyasi-Som-2/publication/368435546/figure/fig1/AS:11431281160113781@1684597623669/Benchmark-LVAC-interconnected-islanded-microgrid-test-system-31_Q320.jpg)
Due to limited reserves and 100% inverter-based resources in an islanded residential microgrid (IRM), largefrequency oscillations may arise during load/generation fluctuations. As an independent grid-forming unit, a battery energy storage system (BESS) can participate in load-frequency control (LFC) to achieve environment-friendly and reliable supp...
Context in source publication
Context 1
... proposed LFC model is now A benchmark CIGRE TF C6 : 04 : 02 low voltage ac (LVAC) IIRM system is developed on MATLAB/Simulink platform [31]. The 400 V, 50 Hz test model comprises three identical microgrids with a ring architecture, as shown in Table II. All IRMs have similar system specifications, and the detailed structure of MG 1 is shown in Fig. 8. Two BESS units and a solar photovoltaic (PV) panel are the generation sources for each microgrid. The PV is operated in the maximum power point tracking control mode at a unity power factor. All BESS units of each IRM are operated in grid-forming mode. The details of the total demand of each IRM is mentioned in Table II. The loads are ...
Citations
... Different studies have been reported in the literature that consider BESSs for improving the operation of power systems. In [5], a reserve control level is proposed to be added in the conventional load-frequency control architecture to provide frequency support to disturbance-affected areas with the help of a set of BESS units available reserve capacity. In [6] a new methodology is proposed based on dynamic grid response and various BESS response characteristics to optimise the fast frequency response reserves and prevent the frequency from breaching the under-frequency load shedding thresholds. ...
... W HEN operating islanded microgrids (MGs), gridforming (GFM) sources are required to establish and maintain voltage and frequency while meeting power reserve requirement (PRR) at all times to effectively manage sudden load increases. These GFM functions play a pivotal role in ensuring reliable and stable MG operation [1], [2]. ...
This paper introduces under-frequency load shedding (UFLS) schemes specially designed to fulfill the power reserve requirements in islanded microgrids (MGs), where only one grid-forming resource is available for frequency regulation. When the power consumption of the MG exceeds a pre-defined threshold, the MG frequency will be lowered to various setpoints, thereby triggering UFLS for different levels of load reduction. Three types of controllable devices are considered for executing UFLS: sectionalizers, smart meters, and controllable appliances. To avoid unnecessary UFLS activation, various time delay settings are analyzed, allowing short-lived power spikes caused by events like motor startups or cold-load pickups to be disregarded. We tested the proposed UFLS schemes on a modified IEEE 123-bus system on the OPAL-RT eMEGASIM platform. Simulation results verify the efficacy of the proposed approaches in restoring power reserves, maintaining phase power balance, and effectively handling short-lived power fluctuations. Furthermore, in comparison to sectionalizer-based UFLS, using smart meters or controllable loads for UFLS allows for a more accurate per-phase load shedding in a progressive manner. As a result, it leads to better balanced three-phase voltage and serves more loads.
... One solution to this problem is to use real-time communication. For example, a reserve control proposed in [8] provides inertia support using BESSs in microgrids. This method relies on communication within the microgrid as well as between different microgrids to transmit inertial power information. ...
There is a critical need to increase power system inertia during the grid transformation. However, in a low-voltage dc (LVDC) microgrid, many potential inertia contributors, such as energy storage systems, are linked to the local dc bus and managed by their individual distributed controllers. This configuration results in a lack of access to grid frequency information, limiting their ability to emulate inertia. To address this challenge without relying on real-time communications, this article proposes a power system inertia enhancement scheme based on LVDC microgrids. This scheme ensures that all potential units within the LVDC microgrids can be mobilized and independently configured to enhance the power system inertia. Furthermore, it also accounts for and compensates for various disturbances encountered within LVDC microgrids, like load switching. Experimental verifications are provided, demonstrating the effectiveness of the proposed method.
... This solution offers good conversion efficiency, but surprisingly does not guarantee good energy usage in the sum of all three phases. Fig. 7 demonstrates comparison of energy production in installed PV system, energy consumption in shelter, energy supply from grid and energy injection into the grid [17,18,20,22]. The annual results are in distribution similar to previous case, but absolute values significantly differ. ...
The paper deals with optimisation of energy storage systems technology for emergency shelters (tiny houses) for Ukrainian War refugees. Huge number of Ukrainian citizens lost their houses or had to leave their homes. These refugees increase population in the rest of Ukraine what escalates problems with accommodation and integration into native communities. Emergency living in communal properties has unpleasant influence on the communities and is acceptable just for limited period. It becomes important to build new quarters or urban areas using cheap but energy efficient technologies. This research is based on real shelter project realised between Ukrainian non-government organisation Synergy and German development agency weChange. Main task of this paper is optimisation of energy strategy in community consisting of hundreds or thousands units and called shelter city. Solution of one single tiny house with implemented RES is task deeply evaluated in several projects, but we must take into account cooperation of large amount of units to limit total influence on Ukrainian distribution and transmission networks. Ukrainian infrastructure was already in unpleasant state before war and new connections of these consumers would dramatically overload existing infrastructure. This task is yet more complicated in nowadays war conditions, where crucial parts of the networks are being repeatedly damaged. From this point of view, it is essential to design the shelter community like consumer o prosumer with perfectly balanced load and production chart. The shelters should be built in passive standard to achieve minimal acquisition and operational costs. Also very efficient but cheap energy storage system must be integrated on the level of particular shelter or entire shelter city. Influence of various battery technologies using different coupling schemes is being discussed. AC coupling, DC coupling with intermediate circuit or PV generator circuit are tuned for specific load charts to optimise the influence on distribution network.
In this article, a multifunction control scheme is proposed for battery energy storage system (BESS) as an independent grid-supporting distributed energy resource in islanded/stand-alone microgrids (MGs) including synchronous generator. The proposed controller increases the utilization factor of the BESS to participate in electricity market ancillary services using its available unused capacity. The proposed controller incorporates adaptive frequency control, voltage regulation, as well as unbalanced load compensation. Additionally, an adaptive high-pass filter is proposed which enables the BESS to compensate for frequency deviations according to its state-of-charge for a longer effective life span of batteries. Furthermore, a voltage control loop is integrated to regulate the BESS point of common coupling voltage during low-voltage conditions by injecting reactive current. Finally, the available capacity of the BESS grid-connected converter is utilized to compensate for the unbalanced currents drawn by the loads. Simulation and experimental tests are compared under several scenarios to validate the proposed controller performance. The results reveal the efficacy of the proposed controller in maximizing the BESS utilization factor in islanded/stand-alone MGs.
This study introduces an optimization model and evaluates the performance of various metaheuristic optimization techniques in solving the sizing problem for an on-grid hybrid renewable energy system (HRES), comprising solar photovoltaic (PV) panels, diesel generators (DG), wind turbines (WT), and battery storage systems (BSS). A university campus was selected as a case study to assess the effectiveness of the proposed HRES. The optimization focuses on minimizing the annual system cost (ACS), the levelized cost of energy (LCOE), and the total net present cost (TNPC), while ensuring that the annual load demand is met and the load power supply probability (LPSP) remains within acceptable limits. The decision variables include the sizes of the PV and WT sources, the power transfer capacity of the inverter to the load, and the capacities of the BSS and DG. The snake optimization algorithm (SOA) was employed to optimize the objective function, taking into account constraints including the maximum and minimum sizes of system components, the renewable energy fraction, and reliability measures such as LPSP. The performance evaluation of on-grid hybrid systems is based on their costs, reliability, and greenhouse gas emissions reduction. Detailed mathematical models are provided to estimate the power output of the hybrid system. The results indicate that the combination of PV, WT, and BSS offers the best performance in terms of ACS, LCOE, TNPC, and reliability indices. Furthermore, a comparison of SOA with other algorithms, including gray wolf optimization (GWO), reptile search algorithm (RSA), firefly algorithm (FFA), battle royale optimization (BRO), and ant colony optimization (ACO), shows SOA’s superior capabilities in system design, achieving lower costs and better reliability indices. The findings also reveal that TNPC, ACS, and LCOE are approximately 33% lower than those of a standalone hybrid system in an on-grid setup, with values reaching 3,340,600, 383,020, and 0.1511/kWh, below the commercial electricity rate of $0.35/kWh in Turkey. All analyses were conducted using MATLAB 2022b.
This paper introduces under-frequency load shedding (UFLS) schemes specially designed to fulfill the power reserve requirements in islanded microgrids, where only one grid-forming resource is available for frequency regulation. When the power consumption of the microgrid exceeds a pre-defined threshold, the microgrid frequency will be lowered to various setpoints, thereby triggering UFLS for different levels of load reduction. Three types of controllable devices are considered for executing UFLS: sectionalizers, smart meters, and controllable appliances. To avoid unnecessary UFLS activation, various time delay settings are analyzed, allowing short-lived power spikes caused by events like motor startups or cold-load pickups to be disregarded. We tested the proposed UFLS schemes on a modified IEEE 123-bus system on the OPAL-RT eMEGASIM platform. Simulation results verify the efficacy of the proposed approaches in restoring power reserves, maintaining phase power balance, and effectively handling short-lived power fluctuations. Furthermore, in comparison to sectionalizer-based UFLS, using smart meters or controllable loads for UFLS allows for a more accurate per-phase load shedding in a progressive manner. As a result, it leads to better balanced three-phase voltage and serves more loads.
