Photovoltaic-battery Hybrid System Research Articles

Stand-Alone Hybrid PV System by Using The Bypass Converter Topology to Optimize the Reliable of Device

One of the applications of DC-DC converters in photovoltaic-battery hybrid systems is a two-way converter used for battery charging. The power supplied to the two-way converter experiences twice the power lost during the battery charging process. Therefore, it is necessary to arrange a phovoltaic-battery hybrid system topology so that only one stage of power conversion occurs when charging the battery so that the power loss is smaller. The proposed topology of this system uses three DC-DC converters connected to a battery and a DC bus. The one-way converter used in this system allows cross-connection between other DC-DC converters. Two one-way converters connect the phovoltaics to the DC bus and the photovoltaics to the battery, and the other one-way converter connects the battery to the DC bus. The purpose of using a one-way converter for charging the battery is called a bypass converter so that charging the battery does not go through two power conversions which cause twice the lost power. To make the proposed system more reliable, an inverter is added to the self-contained photovoltaic-battery hybrid system. Therefore, a control system is needed to maintain the DC bus voltage as input to the inverter using a double-loop control system. The two-loop Proportional-Integral control system is used for the DC electricity section while the Proportional-Resonant control system is used as an inverter control to maintain the balance of AC power. The results of system testing using Simulink/Matlab simulations show that the proposed topology uses a one-way converter capable of carrying out the battery charging process and can control the flow of power while maintaining DC and AC voltages.

Strategi Pengisian Baterai pada Sistem Panel Surya Standalone Berbasis Kontrol PI Multi-Loop

This study discusses the power control strategy in a standalone photovoltaic-battery hybrid system. The life-time of the battery will be shorter if the battery is often charged with high current and exceeds its State-of-Charge (SoC). Therefore, a control method is needed to control the power flow on the DC bus and the charging current as well as the SoC of the battery so that the battery has a long life-time. The proposed system uses two dc-dc converters to connect photovoltaic (PV) and lead-acid batteries to the load. The unidirectional DC-DC converter is used as the interface between the PV and the DC bus, the bidirectional DC-DC converter is used as the interface between the battery and the DC bus. The control strategy plays a role in controlling the power flow between the converter and the load to maintain the balance of power in the system and controlling the battery to support PV when the available PV power is not enough to meet the load. The multi-loop control strategy is proposed in this study, one of the loops is used to maintain the SoC of the battery in order to control the PV output power to avoid over-charging. Another loop is used to ensure the balance of the system's power when the battery is charging at its maximum charge current. The proposed control system is implemented without requiring any conditions for the control to operate. The simulation results show that the proposed multi-loop control can control the power flow in the system while maintaining the maximum charging current and battery SoC limits.

Design and Dynamic Modelling of PV-Battery Hybrid Systems for Custom Electromagnetic Transient Simulation

Battery energy storage systems (BESS) can alleviate the unstable effects of intermittent renewable energy systems, such as solar and wind power systems. In addition, a BESS can level the load of the existing utility grid. The penetration rate of this type of system is expected to increase in the future power grid, i.e., the microgrid. In this paper, a modeling technique is proposed that allows users to customize the photovoltaic (PV) battery hybrid systems. A dynamic power system computer-aided design/electromagnetic transients including DC system (PSCAD/EMTDC) model of a PV battery hybrid system is presented in this paper. Dynamic modeling of PV arrays, BESS, maximum power point tracking (MPPT) algorithms, and bidirectional converters are provided as well. The PV model, battery model, and MPPT control model are designed using a user-defined model (UDM) for custom electromagnetic transient simulation. A control method for stabilizing the output of the PV battery hybrid system is proposed. Finally, a PSCAD/EMTDC simulation is conducted to verify the effectiveness of the operating algorithm.

Model Predictive for Reactive Power Scheduling Control Strategy for PV–Battery Hybrid System in Competitive Energy Market

This article presents an optimal control scheme based on model predictive control (MPC) strategy for a photovoltaic (PV)/battery hybrid system. By considering various trading scenarios of electricity markets in order to maximize profits, an objective function is formulated using variable electricity tariff (VET), battery state of charge (SoC), and availability of solar insolation. The proposed optimal scheme is designed with a two-stage control algorithm based on VET, forecasted solar insolation, and SoC to easily cope with the load demand variation between low and high prices. In this case, the MPC is implemented to predict the SoC in the PV–battery hybrid system by directly calculating it in the first stage while predicting the values of solar irradiance, load consumption, and electricity price. Furthermore, the proposed MPC is used to account for forecasting errors and acts under the given limits to minimize errors and compensate reactive power during the scheduling process. To validate the performance of the proposed control scheme, the PV/battery system is modeled and implemented in MATLAB/Simulink package. Simulation results demonstrate that the proposed optimal control scheme has better performances under various scenarios such as parameter uncertainties and sudden changes.

A Multiport Bidirectional LLC Resonant Converter for Grid-Tied Photovoltaic-Battery Hybrid System

Distributed power generation plants with combined photovoltaic (PV) systems and integrated energy storage for grid-connected applications have seen an increase in research interest in recent years. However, the combination of multiple energy sources requires numerous DC-DC converters and thus becomes more complex. To address this issue, a multiport bidirectional DC-DC LLC resonant converter for grid connected applications is presented in this research. In order to minimize the control complexity of the proposed system, a zone based controller approach with an integrated modified maximum power point tracking (MMPPT) method, which is based on the incremental conductance method, is also developed. This proposed controller is able to regulate the converter voltage and power flow while either delivering or taking power from the utility grid. The converter presented in this study contains a bidirectional buck-boost converter and an LLC resonant converter in addition to a voltage source grid-tied inverter which are interfacing the PV, the battery and the utility. Extensive simulation analyses through MATLAB/Simulink have proved the operations of the proposed topology.

Pv based water pumping system for agricultural sector

In this paper evaluates ways in which can be made efficient water pumping system based on photovoltaic (PV). Battery is incorporated to makes system more reliable. There will be increasing of interest and needs in PV system applications following standard of living improvements will be there due to continuous decreasing of solar cells cost. In both agriculture and domestic, water pumping system powered by solar-cell generators are one of the most important applications. To entrains the pump through control action of motors by developing new efficient and flexible modes, this can be done by considering the solar energy fluctuation and solar energy optimizing necessities. Photovoltaic-battery hybrid system feds the vector control of an asynchronous motor, this vector control is discussed in this paper .PV generator, converter of DC-DC, battery, converter of DC-AC,an induction motor controlled by a vector and the centrifugal pump are investigated in this paper. By perturbed and observe (P & O) algorithm which integrated with boost converter control, a PV generator can be operated at maximum power. At all isolation conditions, the motor supply is also ensured. The effectiveness and feasibility of this approach is shown by the simulation results. Extensive results are presented based on MATLAB/SIMULINK.

Demand side management of photovoltaic-battery hybrid system

In the electricity market, customers have many choices to reduce electricity cost if they can economically schedule their power consumption. Renewable hybrid system, which can explore solar or wind sources at low cost, is a popular choice for this purpose nowadays. In this paper optimal energy management for a grid-connected photovoltaic-battery hybrid system is proposed to sufficiently explore solar energy and to benefit customers at demand side. The management of power flow aims to minimize electricity cost subject to a number of constraints, such as power balance, solar output and battery capacity. With respect to demand side management, an optimal control method (open loop) is developed to schedule the power flow of hybrid system over 24 hours, and model predictive control is used as a closed-loop method to dispatch the power flow in real-time when uncertain disturbances occur. In these two kinds of applications, optimal energy management solutions can be obtained with great cost savings and robust control performance.

A wind–PV-battery hybrid power system at Sitakunda in Bangladesh

The measured wind data of Local Government Engineering Department (LGED) for 2006 at 30 m height shows a good prospect for wind energy extraction at the site. For a few months and hours the speed is below the cut in speeds of the available turbines in the market. The predicted solar radiation data from directly related measured cloud cover and sunshine duration data of Bangladesh Meteorological Department (BMD) for 1992–2003 indicates that a reliable power system can be developed over the year if the solar energy technology is merged with the wind energy technologies for this site. This research work has studied on optimization of a wind–photovoltaic-battery hybrid system and its performance for a typical community load. The assessment shows that least cost of energy (COE) is about USD 0.363/kWh for a community using 169 kWh/day with 61 kW peak and having minimum amount of access or unused energy. Moreover, compared to the existing fossil fuel-based electricity supply, such an environment friendly system can mitigate about 25 t CO 2/yr. The analysis also indicates that wind–PV-battery is economically viable as a replacement for conventional grid energy supply for a community at a minimum distance of about 17 km from grid.