Simulation and modelling of micro-grid with energy storage system

2013 European Modelling Symposium, 2013

Microgrid is a part of the power distribution system which uses renewable energy based of power generation connected to the grid system. Multi energy power generation is composed of renewable energy systems including photovoltaic, wind turbine, energy storage and local loads. Testbed of a microgrid system is the technique to ensure stable operation during faults and various network disturbances in grid and islanding connected mode. In this paper the microgrid using renewable energy consist of a 3 kW photovoltaic, with 30 pieces of 12V for 100Ah battery bank, DC/DC converter, charge controller for battery, single phase DC/AC inverter and various loads (resistor, capacitor, inductor) are develop. The AC buses 240V voltage include with isolation transformer to simulate the grid voltage level by Matlab/Simulink software.

Due to intermittency in the natural sources and the variations in load, energy balance operation demands storage. The commonly preferred choice of energy storage in micro grid is valve regulated lead acid batteries. When batteries are used as energy storage, due to its low power density, the charge and discharge rate is low. It causes severe stress on the battery under quick load fluctuations and results in increase in the number of charge/discharge cycles. Hence, the lifetime of the battery reduces. The super capacitors have high power density and it can react speedily to quick load fluctuations. However, super capacitors alone cannot be used as energy storage as it cannot supply load for a longer time. Hence, this paper proposes a combined energy storage using batteries and super capacitors with high energy and power density. The photovoltaic (PV) based micro grid with combined energy storage is designed and the control strategy is validated for different atmospheric and load conditions. At present, DC microgrid is an effective solution to integrate renewable energy sources which are DC power supply with DC loads. A DC microgrid structure consisting of photovoltaic generation system, hybrid energy storage systems and AC main grid, is presented in this paper. A new power management strategy for this DC microgrid is proposed. The control strategy divides the DC bus voltage into seven ranges by six critical voltage values which are employed as the represents of power states and according to the range which the bus voltage belongs to the operation mode of the system can be automatically judged and switched freely. A hybrid energy storage system in this microgrid that contains two complementary type storage elements-battery and super-capacitor, can enhance the reliability and flexibility of the system based on their special supply logical. The proposed concept is done with grid connected mode and standalone mode or local loads. Further it is extended to industrial applications using an induction motor at the load and performance of the induction motor is observed and simulated using MATLAB/SIMULINK software.

The Open Renewable Energy Journal, 2013

Renewable source based micro-generations such as wind and hydro offer the best potential for emission free power in future power systems. This paper investigates the technical issues related to stable and autonomous operation of a micro-grid system consisting of renewable power sources. A small hydro generation unit and a wind farm are the main renewable power generation units in the proposed micro-grid system. The system under investigation represents a case study in Newfoundland and Labrador, Canada. The availability of the utility grid and the intermittent nature of wind power generation are taken into consideration when identifying the operational modes of the proposed micro-grid system. The investigations are carried out through dynamic modeling and simulation of the proposed micro-grid system in different operational modes. The components models of the proposed micro-grid system are also presented in this paper. The investigations reveal that appropriate control techniques are required to be developed depending upon the operational modes of the proposed system with some additional arrangements. Such arrangements include the type of energy storage unit, reactive power compensation, the management of excess power in the system due to the wind generator etc. The control concepts with additional necessities are also outlined in this paper. This paper concludes that the development of such control concepts is essential to ensure stable and automatic operation of the proposed micro-grid system while maintaining the system voltage and frequency in their rated values.

Renewable energy sources (RES's) is the major sourceof electrical energy in future, the available renewable energysystems are solar, wind, fuel cell out of these solar system is mostpopularly used because this source hugely available in nature, thisrenewable energy source (RES) is most in demand foragricultural, industrial applications. In the agricultural fieldrenewable energy source (RES) is feeding the motor, to have highefficiency for the motor. Motor is design for high voltage, whereas to have high efficiency for solar system it is designed for lowvoltage.This paper explains the effective operation of Induction motor is based on the choice of suitable high voltage gain converter system that is fed to Induction Motor. The design and operation of proposed system that is fed to Induction Motor is simulated using MATLAB/SIMULINK.

IEEE Transactions on Industrial Electronics, 2014

This paper presents a new strategy to control the generated power from energy sources existing in autonomous and isolated microgrids. In this particular study, the power system consists of a power electronic converter supplied by a battery bank, which is used to form the ac grid (grid former converter), an energy source based on a wind turbine with its respective power electronic converter (grid supplier converter), and the power consumers (loads). The main objective of this proposed strategy is to control the state of charge of the battery bank limiting the voltage on its terminals by controlling the power generated by the energy sources. This is done without using dump loads or any physical communication among the power electronic converters or the individual energy source controllers. The electrical frequency of the microgrid is used to inform the power sources and their respective converters about the amount of power that they need to generate in order to maintain the battery-bank charging voltage below or equal its maximum allowable limit. Experimental results are presented to show the feasibility of the proposed control strategy.

Electronics

Recently, the penetration of energy storage systems and photovoltaics has been significantly expanded worldwide. In this regard, this paper presents the enhanced operation and control of DC microgrid systems, which are based on photovoltaic modules, battery storage systems, and DC load. DC–DC and DC–AC converters are coordinated and controlled to achieve DC voltage stability in the microgrid. To achieve such an ambitious target, the system is widely operated in two different modes: stand-alone and grid-connected modes. The novel control strategy enables maximum power generation from the photovoltaic system across different techniques for operating the microgrid. Six different cases are simulated and analyzed using the MATLAB/Simulink platform while varying irradiance levels and consequently varying photovoltaic generation. The proposed system achieves voltage and power stability at different load demands. It is illustrated that the grid-tied mode of operation regulated by voltage so...

Renewable energy obtained from the environment is an alternative option for providing clean energy to homes and industries. But the power obtained from the renewable energy is not sufficient to meet the demand of consumers individually. This has to be integrated to the grid so that there is an exchange of power during demand. To implement the integration of the DC microgrid plays a significant role. DC Microgrid is an efficient way to combine renewable energy to the grid. At the domestic level, DC microgrids can be efficiently integrated with the distribution and generation of power. Hence they act as effective component in the power system. In this project, we are proposing a DC Microgrid with power Electronics control .The renewable energy sources are Solar and Fuel cells, with storage system is to be integrated to form a DC Microgrid and integrated to the utility grid through Power electronic interface with controller.

Renewable Energy, 2012

The interest on DC micro-grid has increased extensively for the more efficient connection with DC output type sources such as photovoltaic (PV) systems, fuel cells (FC) and battery energy storage systems (BESS). Furthermore, if loads in the system are supplied with DC power, the conversion losses from sources to loads are reduced compared with AC micro-grid. This paper proposes operation and control strategies for the integration of PV and BESS in a DC micro-grid. The proposed control enables the maximum renewable energy utilization during different operating modes of the micro-grid i.e., grid connected, islanded or transition between these two modes, whilst making an allowance for the DC voltage control and DC-loads supply. When the system is grid connected and during normal operation, active power is balanced by the AC grid converter to ensure a constant DC voltage. In order to achieve the system operation under islanding conditions, a coordinated strategy for the BESS, PV and load management including load shedding and considering battery state of charge (SoC), are proposed. Seamless transition of the PV converter control between maximum power point tracking (MPPT) and voltage control modes, of the battery converter between charging and discharging and that of grid side converter between rectification and inversion are ensured for different grid operation modes by the proposed control methods. The DC bus voltage level is employed as an information carrier to distinguish different modes and determine mode switching. MATLAB/SIMULINK simulations are presented to demonstrate the robust operation performance and to validate the proposed control system during various operating conditions.

CCECE 2010, 2010

Micro-grid system is currently a conceptual solution to fulfill the commitment of reliable power delivery for future power systems. Renewable power sources such as wind and hydro offer the best potential for emission free power for future micro-grid systems. This paper presents a micro-grid system based on wind and hydro power sources and addresses issues related to operation, control, and stability of the system. The micro-grid system investigated in this paper represents a case study in Newfoundland, Canada. It consists of a small hydro generation unit and a wind farm that contains nine variablespeed, double-fed induction generator based wind turbines. Using Matlab/Simulink, the system is modeled and simulated to identify the technical issues involved in the operation of a micro-grid system based on renewable power generation units. The operational modes, technical challenges and a brief outline of conceptual approaches to addressing some of the technical issues are presented for further investigation.

Characteristic analysis of operation curve of energy storage system considering typical weather conditions to suppress photovoltaic power fluctuation Nature offers an enormous amount of free energy in the form of Sun [Photovoltaic (PV)]. Therefore, it is interesting to integrate this renewable, everlasting, and echo friendly energy into traditional grid connected power supply. In this study, an energy management system (EMS) is proposed for the proper PV energy integration and utilization into microgrids. For prototype, simulations were performed for 1 kW PV array, 1.5 kV A inverter, and 1.5 kW load employing Lab VIEW. Boolean algebraic operators were incorporated for decisions. A sine wave frequency generator with the desired voltage and frequency measurements was introduced for both grid and PV sources. Numerical indicators are used for current, voltage, and frequency display. The proposed system offers integration and management of PV and national grid power for domestic power utilization. To test the capabilities of the developed EMS, the results were compared with the already established methods. In the developed method, PV is considered as a primary power source for domestic appliances (load) during daytime along with the national grid as a secondary power source. Moreover, to establish its feasibility, economic implications are also discussed. Published by AIP Publishing. https://doi.