Photovoltaic Battery Energy Storage Systems Research Articles

A bi-level inter-phase coordinated control method for voltage regulation in unbalanced LV distribution networks using PV-battery energy storage systems

Photovoltaic systems coupled with battery energy storage (PV-BES) can help to minimize the effects of variability in PV generation including voltage problems in low voltage distribution grids (LVDNs). Therefore, a joint centralized-decentralized method consisting of two control levels based on sensitivity analysis is proposed in this paper, which employs the BES charging and discharging control in the first level and reactive power capability of inverters in the second control level. When the BES charging and discharging control is insufficient for voltage regulation, the second level of the proposed method is triggered. For full utilization of the BES capacity and to ensure adequate capacity for the following day's voltage regulation needs, an enhancement algorithm is applied to the voltage to active power sensitivity coefficients. All of the voltage sensitivity coefficients are calculated by a central controller using an offline procedure and sent to the PV-BES inverters to determine the amount of active and reactive power in real-time according to the measured local voltage. Taking into account the inter-phase voltage effects, a request for Var compensation signal flow with inter-phase coordination constraints is utilized to properly coordinate the inverters in reactive power control. The proposed method can efficiently regulate voltage by preventing over and under-voltage problems, improving the average total voltage deviation (TVD), reducing the total reactive power absorption and injection by the inverters, and avoiding reduction in PV generation. To evaluate the performance of the proposed control method, it is compared with the commercially available inverter voltage control techniques in an unbalanced residential test feeder. Moreover, a comparison is conducted between the proposed method and an adaptive decentralized control approach presented in the literature. Furthermore, a three-phase Volt-Var strategy, with and without the inter-phase coordination constraints, is simulated that indicates the necessity of the constraints for proper coordination.

Review of Photovoltaic–Battery Energy Storage Systems for Grid-Forming Operation

Coordinated control technology attracts increasing attention to the photovoltaic–battery energy storage (PV-BES) systems for the grid-forming (GFM) operation. However, there is an absence of a unified perspective that reviews the coordinated GFM control for PV-BES systems based on different system configurations. This paper aims to fill the gap by providing a comprehensive review of coordinated GFM control strategies for PV-BES, considering various system configurations. Typical configurations of PV-BES systems are explored, followed by a detailed discussion of conventional GFM control methods used in the PV-BES systems. Furthermore, coordinated GFM controls are analyzed in PV-BES systems based on different configurations, providing the common DC bus configuration as a widely adopted configuration due to its more control degrees of freedom and ease of expansion. Moreover, the mode division and switching coordinated control based on the system power is the most widely used. Furthermore, challenges in the coordinated GFM controls for the PV-BES system in future applications are briefed and emphasized before the conclusion.

A wild horse-assisted decentralized control strategy for a PV-battery energy storage system in a DC microgrid

A wild horse-assisted decentralized control strategy for a PV-battery energy storage system in a DC microgrid

Robust Control and Energy Management in Grid-connected Photovoltaic-battery Energy Storage Systems

Robust Control and Energy Management in Grid-connected Photovoltaic-battery Energy Storage Systems

A holistic techno-economic feasibility analysis of residential renewable energy systems: An insight into Turkish case

This study conducts a detailed techno-economic evaluation of residential renewable energy system (RRES) in Türkiye, focusing on the city of Kahramanmaras with high solar potential and utilizing real-site measured PV data in the city. To this end, a comprehensive RRES model, incorporating various system configurations are developed. In order to represent all PV-Battery energy storage system (BESS) operating configurations, six different cases are defined. Then, novel energy management strategies are proposed for the cost-efficient allocation of available energy and to improve the techno-economic performance of the RRES. To conduct a comprehensive feasibility analysis from all aspects, various economic metrics such as net present value, simple payback period (SPP), discounted payback period (DPP), internal rate of return (IRR), profitability index (PI), and levelized cost of energy (LCOE), together with energy-related performance metrics like self-sufficiency and grid-dependency rates are employed. Furthermore, a sensitivity analysis is carried to observe the impacts of pricing scheme and system cost&sizing on the evaluation metrics. On the other hand, as a technical assessment, reliability index (RI) is calculated for each case to discuss the loss of load probability. MATLAB R2020b software is utilized for modelling and energy management purposes. The numerical results indicate that the most feasible system under current financial circumstances and renewable energy policy is rooftop PV system with a SPP of 8.38 years, a DPP of 7.71 years, an IRR of 11.64 %, a PI of 2.72, and a LCOE of 0.026 $/kWh, whereas the least feasible system is proven to be sun tracking PV-BESS system on PV charge mode with a SPP of 12.08 years, a DPP of 10.73 years, an IRR of 7.61 %, a PI of 1.69, and a LCOE of 0.227 $/kWh. Moreover, it is observed that charging the BESS from the grid instead of PV energy procures higher financial returns for the end-user such that SPP, DPP, IRR, PI, and LCOE improve to 10.95 years, 9.83 years, 8.40 %, 1.87, and 0.198 $/kWh, respectively for the system of configuration of sun tracking PV with BESS on grid charge mode compared to sun tracking PV with BESS on PV charge mode. Also, all PV-BESS operational configurations can meet the feasibility criteria through improved incentives and cost reductions although the cost-benefit ratio of BESSs is not yet at the desired level. The results of technical evaluation indicate that charging the BESS from the grid and smaller BESS sizes serve to reduce the loss of load probability, resulting in an improvement in the reliability index of the RRES. Overall, this study provides a holistic insight for promoting RRESs in Türkiye through a detailed techno-economic performance analysis.

Enhancing sustainable and climate-resilient agriculture: Optimization of greenhouse energy consumption through microgrid systems utilizing advanced meta-heuristic algorithms

Greenhouses offer controlled microclimates that enable year-round cultivation, improving food security and agricultural productivity. However, greenhouses are energy-intensive, with heating accounting for a significant portion of the associated costs. This study explores optimal microgrid configurations, economic viability, and policy recommendations for sustainable greenhouse agriculture in Nigeria. An in-depth energy assessment of a reference greenhouse in a South Korean facility is conducted. Distinct climatic differences between South Korea and Nigeria are highlighted, emphasizing the need for tailored greenhouse designs and energy solutions. Shifting focus to Nigeria, this study investigates the feasibility of hybrid renewable energy systems with a focus on wind and solar power across six geopolitical zones in Nigeria. The analysis encompasses technical, economic, and policy aspects, providing a holistic perspective on renewable energy adoption. Notably, the study uses an advanced optimization model, Teaching and Learning–Based Optimization algorithm, to assess the net present cost and baseload supply reliability, offering valuable insights for investors and policymakers. The result indicates diverse energy requirements across Nigeria, with total monthly peak energy demands ranging from 5374.80 kWh in the Southeast to 17,115.76 kWh in the Northwest, and a notable variation in the Levelized Cost of Electricity (LCOE), with the lowest at $0.07327 in Kano. Specifically, in Ogun, the net present cost for the WT-PV-ESS system stood at $520,935.45, while the PV-ESS system cost was substantially lower at $500,444.41. This confirms the effectiveness of location-specific analysis and shows the suitability of photovoltaic–battery energy storage systems for Nigeria's diverse regions, with unique considerations for specific areas. Policy recommendations, including feed-in tariffs, renewable portfolio standards, net metering, research support, and market development, provide a holistic framework for the adoption of renewable energy and sustainable agriculture. Improving infrastructure, market access, and financing for smallholder farmers is integral for improving food security and standards of living in rural Nigeria. In conclusion, Nigeria can leverage renewable resources to revolutionize its energy and agriculture sectors, setting an example for a sustainable and resilient future.

Finite control set model predictive control of three-port converter for interfacing a PV–battery energy storage system to a three-phase stand-alone AC system

Abstract This paper proposes a multiport bidirectional non-isolated converter topology that provides advantages in terms of simultaneous multiple operations, single-stage conversion, high power density and reduced power losses due to the lower number of switches. The proposed multiport converter uses a centralized non-linear controller known as a finite control set model predictive controller to manage the flow of power between different ports. It deals with the parallel operation of photovoltaic and battery energy storage systems for stand-alone alternating current (AC) systems. The converter connects the lower voltage battery to the photovoltaic port using a bidirectional buck/boost converter and the photovoltaic port is linked to the stand-alone AC load through a three-phase full-bridge inverter. Each leg of the three-phase converter will act as a bidirectional direct current (DC)/DC converter as well as an inverter simultaneously. Only six switches manage the power transfer between all the connected ports of photovoltaic–battery energy storage system linked to the stand-alone AC load. The proposed multiport converter is mathematically modelled and controlled by a finite control set model predictive controller. The system is validated in simulation (1-kW rating) and experimental environment (200-W rating). The hardware prototype is developed in the laboratory and the controller is implemented on the field-programmable gate array board. Two independent case studies are carried out to validate the efficacy of the system. The first scenario is for a change in solar irradiance, while the second scenario is for a change in the output load.

Optimasi Sistem Panel Surya dan Baterai Untuk Meminimasi Biaya Pemakaian Energi Listrik Rumah Tangga

The use of photovoltaic-battery energy storage systems to meet the electrical energy needs of house while reducing the cost of using electricity from the grid is increasing. Optimization of this system can be performed by optimizing the energy consumption of solar panels and batteries. This paper presents the optimization of solar panels and battery systems to minimize the cost of using electricity from the grid. Circuit models and mathematical formulations of grid-connected solar panel and battery systems were created for optimization purposes. The optimization problem is solved by using mixed-integer linear programming and Pyomo software based on the Python programming language. Data on household electricity consumption and output power from two solar panels with a capacity of 100 Wp and 200 Wp respectively were obtained from the results of simultaneous measurements for one month. The test results show that the optimization of the solar panel and battery system can reduce the cost of electricity consumption at home with optimal energy consumption from solar panels and batteries.

A simple and easy-to-implement battery equalization strategy for photovoltaic-battery energy storage systems

Abstract For renewable energy sources such as photovoltaic (PV), energy storage systems should be prioritized as they smooth the output well. Although lithium-ion battery energy storage systems are favored for their excellent performance, the large number of batteries connected in series and parallel may lead to inconsistent battery packs, which can cause system problems. Therefore, battery equalization techniques should be employed. This article proposes a battery equalization technique suitable for PV battery energy storage systems. In terms of the equalization circuit, we propose an equalization circuit consisting of a switch-selective circuit and a Cuk circuit, which is simple and easy to expand; in terms of the equalization strategy, we adopt a highly robust fuzzy logic control to better adapt to PV battery energy storage systems, we developed a set of control rules suitable for this equalization strategy. We have investigated the principle of the proposed battery equalization technique and verified it experimentally during the battery pack's resting, charging, and discharging. The consistency of the battery pack is significantly improved as a result.

Transitioning from coal to solar: A cost-benefit analysis for sustainable power generation in Indonesia

<abstract> <p>The greenhouse gas (GHG) emissions contribution from power generation in Indonesia reaches 40% of the total (GHG) emissions in the energy sector because of the use of fossil fuels. The government aims to minimize GHG emissions in the power generation sector, one of which is the phase-out of coal power plants and replacing them with integrated photovoltaic (PV) power plants with battery energy storage systems (BESS). A cost-benefit analysis compared two development scenarios for 2023–2060. The base scenario continues developing coal power plants, and the phase-out scenario replaces coal power plants with integrated PV power plants and BESS. The analysis is solely focused on the financial costs and benefits for power plant investors. The results indicate that the present value of costs for the base scenario from 2023–2036 is initially lower compared to the phase-out scenario. However, in the long term, the costs of the phase-out scenario will gradually decrease and become more affordable. The benefit-cost ratio for the phase-out scenario is 2.36, while the base scenario is 2.12, indicating that the phase-out scenario is more prospective for future development. Additionally, the phase-out scenario has the advantage of achieving the net-zero emissions target by 2056 compared to the base scenario.</p> </abstract>

Hybrid Solar-Hydropower Systems for Green Energy Production: A Comprehensive Analysis

This paper presents a detailed analysis of hybrid energy systems combining solar photovoltaic (PV) panels and hydropower technologies. Focusing on the increasing popularity of Archimedes screw generators for low head sites, we examine the efficiency and environmental benefits of such systems, particularly in reducing greenhouse gas emissions as part of global efforts like the Paris Agreement. We explore the integration of solar and hydropower systems in the context of Brazil’s renewable energy hybridization and discuss the challenges of their stochastic nature on power grid integration. The paper delves into the theoretical foundation, mathematical simulations, and optimization models that enable these hybrid systems to maintain energy and irrigation balance. The paper also investigates the use of photovoltaic-battery energy storage systems in building power supply and the potential of micro-grids featuring an array of renewable energy technologies. Ultimately, we present a novel approach to off-grid hybrid system deployment contributing to sustainable development goals.

Voltage and frequency control of solar – battery – diesel based islanded microgrid

Abstract Islanded microgrids with low-inertia distributed energy resources (DERs) are prone to frequency fluctuations. With the increasing integration of DERs in microgrids, the complexity of control and stability has also increased. Moreover, the integration of DERs into microgrids may result in a power imbalance between energy supply and demand during sudden changes in load or energy generation. This can cause frequency variations in the microgrid, which could have disastrous consequences such as equipment damage or even blackouts. This paper proposes a control strategy to ensure the efficient operation of an islanded hybrid microgrid consisting of a PV generator, battery energy storage system (BESS), and emergency diesel generator. According to Energy Exchange Model proposed in this paper, the hybrid system presented operates independently without being connected to the electrical grid, where the PV system and BESS act as the main energy sources, while the emergency diesel generator provides active power backup with voltage and frequency regulation. The novel in this paper is also that DER aids in frequency regulation during active power transients by delivering and absorbing active power in accordance with the inverter's suggested P droop control strategy. In this way inverter droop control decreases system frequency nadir emulating so called “synthetic inertia”. To design both the islanded hybrid system and the proposed control strategy, the MATLAB/Simulink environment is utilized. Based on the results, it can be concluded that the analyzed microgrid system is capable of maintaining stability and operating efficiently in a range of operating conditions.

Optimisation of a standalone photovoltaic electric vehicle charging station using the loss of power supply probability

The UK is planning to ban the sale of fuel vehicles entirely by 2035 and electric vehicles will be a potential alternative to fuel vehicles. The increase in electric vehicles will increase the charging demand. Standalone charging stations are a potential solution to alleviate the grid challenges of increased charging demand. In this work, the authors investigate a reliability analysis of a 2 MW standalone photovoltaic electric vehicle charging station (PVEVCS) using the loss of power supply probability(LPSP). The PVEVCS model consists of a PV system, a battery energy storage system (BESS) and a CS, using the climate data from Camborne, UK and classifying it into high and low irradiation sections. Next, four different charging demand profiles are selected to examine the models’ LPSP. Later, the chosen charging demand profiles are optimised using various combinations of PV systems, BESS and CS. It is concluded that the different solar irradiation had a significant effect on the LPSP. Under the same combination, higher PV capacity has a more positive impact on reducing daytime LPSP, higher BESS capacity has a more significant effect on lowering nighttime LPSP and larger CS capacity has a more significant impact on declining hourly LPSP.

Nonlinear control design and stability analysis of hybrid grid-connected photovoltaic-Battery energy storage system with ANN-MPPT method

The problem of controlling a grid-connected solar energy conversion system with battery energy storage is addressed in this work. The study’s target consists of a series and parallel combination of solar panel, DC/DC converter boost, DC/AC inverter, DC/DC converter buck-boost, Li-ion battery, and DC load. The main objectives of this work are: (i) PV voltage regulation: the PV panel voltage must track a given reference voltage corresponding to the maximum power point. The optimal reference voltage is generated by an optimizer based on the artificial neural network (ANN); (ii) DC link voltage regulation: The DC link voltage must track a reference voltage as closely as possible. (iii) PFC requirement: The grid currents must be sinusoidal with the same frequency and in phase with the voltage grid. The periodic nature of solar energy and the frequent fluctuations in load demand reduce battery life and charging performance. To deal with these limitations and ensure the battery’s safety, a battery energy management algorithm is developed with the following objectives: (iv) CC mode: When the battery’s state of charge is less than 100% (SOC<100%), it indicates that the battery is not fully charged, this aim has been adopted. The battery current should follow a constant reference as closely as possible to the permissible limits battery current; (v) CV mode: When the battery is completely charged, this mode is switched on. The voltage at the battery terminals then achieves its reference signal, which corresponds to the charge state’s of the battery SOC=100%. In addition, the energy management system which generates several energy flow scenarios, in this work, the focus is to balance the energy flows between the load and the different energy sources to minimize the system costs, to ensure the stability of the grid and to improve the power quality. To do this, a mathematical modeling of the overall system was performed. Subsequently, backstepping controllers are then synthesized in order to ensure the control objectives. The closed loop control convergence is formally analyzed using Lyapunov’s stability theory and its performances are illustrated by simulation. As a result, the simulation results indicate that the proposed controllers perform admirably in achieving their objectives.

Performance Assessment of a Grid-Connected Two-Stage Bidirectional Converter for a Combined PV–Battery Energy Storage System

This paper presents a comprehensive performance assessment of a two-stage power electronic (PE) converter for interfacing the grid of a lithium-ion battery energy storage system (Li-BESS) for building-integrated PV (BIPV) applications. A performance assessment of the control system was conducted for the two-stage PE interface with a common DC-link, which consisted of a bi-directional boost converter with a cascaded PI controller and an AC/DC converter with proportional-integral (PI) and proportional-resonant (PR) controllers. The assessment covered loss analysis and useful lifetime estimation for the 10 kW PE interface with a wide-bandgap SiC power MOSFET at different loads for both the charging and discharging modes of a 50 kWh lithium-ion battery system. Additionally, a performance comparison of various switching frequencies was performed. It was observed that the system was stable up to a switching frequency of 30 kHz, and that increasing the switching frequency improved the responsiveness of the converter by decreasing the settling time; however, there were diminishing returns at higher switching frequencies. To obtain a proper balance between responsiveness and lower loss, a switching frequency of 10 kHz was selected.

Dynamic Optimal Power Dispatch in Unbalanced Distribution Networks with Single-Phase Solar PV Units and BESS

Battery energy storage systems (BESSs) are a promising solution for increasing efficiency and flexibility of distribution networks (DNs) with a significant penetration level of photovoltaic (PV) systems. There are various issues related to the optimal operation of DNs with integrated PV systems and BESS that need to be addressed to maximize DN performance. This paper deals with day-ahead optimal active–reactive power dispatching in unbalanced DNs with integrated single-phase PV generation and BESS. The objectives are the minimization of cost for electricity, energy losses in the DN, and voltage unbalance at three-phase load buses by optimal management of active and reactive power flows. To solve this highly constrained non-linear optimization problem, a hybrid particle swarm optimization with sigmoid-based acceleration coefficients (PSOS) and a chaotic gravitational search algorithm (CGSA)called the PSOS-CGSA algorithm is proposed. A scenario-based approach encompassing the Monte Carlo simulation (MCS) method with a simultaneous backward reduction algorithm is used for the probabilistic assessment of the uncertainty of PV generation and power of loads. The effectiveness of the proposed procedure is evaluated through aseries test cases in a modified IEEE 13-bus feeder. The simulation results show that the proposed approach enables a large reduction in daily costs for electricity, as well as a reduction in expected daily energy losses in the DN by 22% compared to the base case without BESS while ensuring that the phase voltage unbalance rate (PVUR) is below the maximum limit of 2% for all three-phase buses in the DN.

Design and implementation of power management system integrated with cooperative systems for an apartment building

The power management system (PMS) for detached houses has been studied for many years; however, the PMS for apartment buildings (APBs) is not fully understood considering the structures of the APBs. Furthermore, electric vehicle (EV) batteries, photovoltaic (PV) generation, and battery energy storage system (BESS) can be used as distributed energy resources. Therefore, this study proposes an integrated PMS that optimizes the power schedules of individual residents, EV batteries, and common facilities (PV power generation and BESS) in APBs considering the time-of-use pricing policy. To develop the proposed system, a two-stage optimization was adopted using a genetic algorithm. For individual households, the first stage had three objectives: electricity cost, peak power, and user comfort. For the APB, the second stage had two objectives: total electricity cost and total peak power. To evaluate the performance of the proposed system, computational experiments were conducted in three cases: 1) unmanaged schedule, 2) conventional system, and 3) proposed system. For 50- and 100-unit APBs, the proposed PMS had lower total electricity costs (53119 JPY, 106150 JPY) and total peak power demands (184 kW, 366 kW) than the total electricity costs (54744 JPY, 109517 JPY) and total peak power demands (214 kW, 423 kW) of the conventional PMS. Based on a case study that used the proposed two-stage system with different weighting factors, the trade-off relationship among the five objectives of the proposed PMS was obtained. These findings suggest that the all-inclusive power scheduling of the APBs can be managed by dividing the comprehensive demand into individual household and common facility power demands, including cooperative systems. These results provide an important opportunity to advance the understanding of integrated PMS and cooperative systems for APBs. Further research is required to establish the dynamic relationships between households and APBs.

Voltage Regulation in Excessive Penetration of Solar Rooftop Distribution System Using Battery Energy Storage System

This paper presents the methodology and solutions for mitigating voltage variation under steady conditions caused by differing levels of PV penetration in low-voltage (LV) rural networks. The LV rural area of the Provincial Electricity Authority (PEA) North-East area 3 District of Thailand is used as a case study with load profiles from Geographic Information System (GIS) software. Moreover, rooftop PV power generation is calculated using recorded data on irradiation in Nakhon Ratchasima Province. DIgSILENT Power Factory software is used to simulate and analyze the quality of the proposed method by focusing on the voltage level at the end of the line or dead-end (DE) of the LV network. The results show overvoltage at the DE under the high rooftop PV penetration. The battery energy storage system (BESS) is applied to mitigate the problem of low quality. Meanwhile, the system is operated by examining load demand and rooftop PV power generation to define the state of charging and discharging conditions. The proposed method can be integrated into the algorithm of a rooftop PV system and BESS local control in the home energy management system (HEMS). The results show that the proposed method can reduce the voltage variation problem existing in the PEA standard while improving the voltage level at all DEs.

Optimization strategy and control technology of four-port SOP for distribution network with PV and BESS

This paper proposes a four-port soft open point (FSOP) with photovoltaic (PV) and battery energy storage systems (BESS) and its optimization strategy and control technology. Combining PV output, BESS characteristics, peak and valley electric charges, transformer operation efficiency, and soft open point (SOP) characteristics, the operation criteria under different operating conditions are formulated to improve the economy of the distribution network. In this paper, the power distribution optimization algorithm is established based on the transformer consumption characteristic model and the equal consumption incremental rate criterion to improve the power utilization rate and the system’s economy. The system doesn’t require an additional central controller and transmits control signals through the DC link of FSOP to realize the coordinated operation of all ports. The simulation results show that the system and the optimization strategy can realize the system’s coordinated operation and improve the distribution network’s economy.

The Full Load Voltage Compensation Strategy in Capacity Configuration of燯PQC Integrated PV-BESS

Unified power quality conditioner (UPQC) with energy storage is commonly based on conventional capacity configuration strategy with power angle control. It has problems such as phase jumping before and after compensation. DC-link cannot continuously emit active power externally. Therefore, this paper presents the compensation strategy of full load voltage magnitude and phase in capacity configuration of UPQC. The topology of UPQC is integrated a series active power filter (SAPF), a shunt active power filter (PAPF) and a photovoltaic-battery energy storage system (PV-BESS). The principle of full load voltage compensation is analyzed based on the PV-BESS-UPQC topology. The magnitude constant of load voltage is maintained by controlling the appropriate shunt compensation current. Then the UPQC capacity configuration is carried out using the full load voltage compensation strategy. The compensation capacity of UPQC series and shunt units are reduced. Finally, the simulation results show that the proposed compensation strategy reduces the capacity configuration by 5.11 kVA (36.4%) compared to the conventional compensation strategy. The proposed strategy can achieve full compensation of the load voltage, which can effectively reduce the capacity allocation and improve the economy of UPQC. It also has the PV-BESS units' ability of providing active power and can stabilize the DC-link voltage.