Battery Integration to the Power Grid and Frequency Regulation

The growing interest in battery energy storage systems (BESSs) at both small-scale and large-scale levels in power grids highlights their significant roles in future power grids. The future grid in the presence of renewable resources such as hydro-power, wind, and solar energy face two major technical challenges; location of potential renewable sources and uncertainty, which can cause serious issues such as blackouts in power systems. However, in both cases, BESSs is one of the promising solutions. While small-scale battery energy storage systems can decrease the need for long-distance heavy load transportation in the power system, which is one of the primary reasons for the blackouts, large-scale BESSs can provide load frequency control to their fast response. A well-managed large-scale battery integration to the power grid reduces load flow deviation in the tie-lines and frequency oscillations caused by small load disturbances. In general, the battery’s small time-constants, fast response, and high energy density creates a large spectrum of potential applications for BESSs in power systems. This thesis focuses on the battery integration to the power system in both distribution and transmission level to evaluate its potential impact on power grid; then, it focuses on the frequency regulation by taking the advantage of the small-scale and large-scale batteries. The first part of this research investigates the small-scale battery integration to the power system in the distribution level and its potential effects on the transmission level\u27s frequency deviation. It is shown that the higher penetration level of the renewables can cause serious issues such as overvoltage, thermal, and frequency deviation issues in the distribution and transmission levels under current tariffs. The load profile\u27s sensitivity to the battery characteristics and its efficiency, and electricity tariffs are studied. Then, tariff modification as one of the promising tools for load profile adjustment is introduced to modify the customers\u27 load profile and mitigate the frequency deviation. The results under modified tariffs are compared to the frequency control results in a small microgrid using model predictive control. In the second chapter, the effect of those new loads on the power flow and inter-area oscillation modes are studied. Then a servomechanism controller is designed to damp the inter-area oscillations. Considering the small time constant of the large-scale battery, we model a large-scale battery integration to the power system to study the effect of its integration on the power system\u27s stability. Finally, centralized and decentralized hybrid controls are designed on the inverter\u27s firing angle to manage the large-scale battery\u27s active and reactive power to damp the oscillations. Results show a notable improvement on frequency deviations

Techno-Economic Optimization of Grid-Connected Photovoltaic (PV) and Battery Systems Based on Maximum Demand Reduction (MDRed) Modelling in Malaysia

Under the present electricity tariff structure in Malaysia, electricity billing on a monthly basis for commercial and industrial consumers includes the net consumption charges together with maximum demand (MD) charges. The use of batteries in combination with photovoltaic (PV) systems is projected to become a viable solution for energy management, in terms of peak load shaving. Based on the latest studies, maximum demand (MD) reduction can be accomplished via a solar PV-battery system based on a few measures such as load pattern, techno-economic traits, and electricity scheme. Based on these measures, the Maximum Demand Reduction (MDRed) Model is developed as an optimization tool for the solar PV-battery system. This paper shows that energy savings on net consumption and maximum demand can be maximized via optimal sizing of the solar PV-battery system using the MATLAB genetic algorithm (GA) tool. GA optimization results revealed that the optimal sizing of solar PV-battery system gives monthly energy savings of up to 20% of net consumption via solar PV self-consumption, 3% of maximum demand (MD) via MD shaving and 2% of surplus power supplied to grid via net energy metering (NEM) in regards to Malaysian electricity tariff scheme and cost of the overall system

Control and Optimization of Energy Storage in AC and DC Power Grids

Energy storage attracts attention nowadays due to the critical role it will play in the power generation and transportation sectors. Electric vehicles, as moving energy storage, are going to play a key role in the terrestrial transportation sector and help reduce greenhouse emissions. Bulk hybrid energy storage will play another critical role for feeding the new types of pulsed loads on ship power systems. However, to ensure the successful adoption of energy storage, there is a need to control and optimize the charging/discharging process, taking into consideration the customer preferences and the technical aspects. In this dissertation, novel control and optimization algorithms are developed and presented to address the various challenges that arise with the adoption of energy storage in the electricity and transportation sectors. Different decentralized control algorithms are proposed to manage the charging of a mass number of electric vehicles connected to different points of charging in the power distribution system. The different algorithms successfully satisfy the preferences of the customers without negatively impacting the technical constraints of the power grid. The developed algorithms were experimentally verified at the Energy Systems Research Laboratory at FIU. In addition to the charge control of electric vehicles, the optimal allocation and sizing of commercial parking lots are considered. A bi-layer Pareto multi-objective optimization problem is formulated to optimally allocate and size a commercial parking lot. The optimization formulation tries to maximize the profits of the parking lot investor, as well as minimize the losses and voltage deviations for the distribution system operator. Sensitivity analysis to show the effect of the different objectives on the selection of the optimal size and location is also performed. Furthermore, in this dissertation, energy management strategies of the onboard hybrid energy storage for a medium voltage direct current (MVDC) ship power system are developed. The objectives of the management strategies were to maintain the voltage of the MVDC bus, ensure proper power sharing, and ensure proper use of resources, where supercapacitors are used during the transient periods and batteries are used during the steady state periods. The management strategies were successfully validated through hardware in the loop simulation

Consideration for a sustainable hybrid electric power mini-grid : case study for Wanale village in Uganda

In this study, a hybrid mini-grid system is designed to supply electricity to a rural village in Uganda. Renewable energy resources are identified, an estimation of the projected village short-term electricity demand is simulated, and using HOMER software, a hybrid mini-grid system is designed, components sized, and the system optimized in terms of cost, and efficient and reliable operation to meet the village demand

Optimal energy control of a grid-connected solar-wind-based electric power plant applying the time of use tariff

Published ThesisFurther combination of renewable sources is needed for improving grid economical management. Therefore, a good energy management of the hybrid renewable plant is more important to make the system more economically feasible. This study will promote to an optimal operational efficiency of a hybrid renewable energy plant. The initial objective will be minimizing the system operation and maintenance costs. Secondly maximizing the sales of energy to the grid based on the time-of-use tariffs scheme. Both wind and solar have tremendous potential for fulfilling the world’s energy needs. Renewable generation, especially from wind and solar concepts are critical technologies needed to address global warming and related issues. Solar and wind power plants exhibit changing dynamics, nonlinearities, and uncertainties challenges that require advanced control strategies to solve effectively. The use of more efficient control strategies would not only increase the performance of these systems, but would also increase the number of operational hours of solar and wind plants and therefore reduce the cost per kilowatt-hour (KWh) produced. The key challenge is to reduce the cost of renewable energies to reasonably priced levels. Control and related technologies will be necessary for solving these complex problems

Analysis, sizing and control of a micro-grid with photovoltaic generation and batteries, for residential applications in the city of Cúcuta, Norte de Santander (Colombia)

Currently, the Colombian electricity sector presents great opportunities for the implementation of electric power generation systems from unconventional energy sources such as photovoltaic solar energy, these opportunities arise from the need to strengthen the national energy matrix to be able to supply the increasing demand for electrical energy of the country, at the same time as the generation system, mainly dominated by generation of hydroelectric energy, is strengthened in front of environmental crises such as those experienced in the past. With this as a reference, the present work carries out a study for the implementation of micro-grid with photovoltaic generation systems and batteries for residential use, within the context of the actual Colombian electricity market, focused on the city of Cúcuta, Norte de Santander. Developing for this purpose a model of the microgrid in Simulink from MathWorks, and evaluating its performance for two particular case studies

Recent Developments of Photovoltaics Integrated with Battery Storage Systems and Related Feed-In Tariff Policies: A Review

The paper presents a review of the recent developments of photovoltaics integrated with battery storage systems (PV-BESs) and related to feed-in tariff policies. The integrated photovoltaic battery systems are separately discussed in the regulatory context of Germany, Italy, Spain, United Kingdom, Australia, and Greece; the attention of this paper is focused on those integrated systems subject to incentivisation policies such as feed-in tariff. Most of the contributions reported in this paper consider already existing incentive schemes; the remaining part of the contributions proposes interesting and novel feed-in tariff schemes. All the contributions provide an important resource for carrying out further research on a new era of incentive policies in order to promote storage technologies and integrated photovoltaic battery systems in smart grids and smart cities. Recent incentive policies adopted in Germany, Italy, Spain, and Australia are also discussed