Sidra Mumtaz

Energy management and control of grid-connected wind/fuel cell/battery Hybrid Renewable Energy System

This manuscript explains an energy management and control of grid-connected Hybrid Renewable Energy System (HRES). It describes a Wind Turbine (WT) and hybrid energy storage system based on hydrogen technology (fuel cell), and battery. DC/DC converters are used to connect all the energy sources and storage system to a common DC bus. The output of DC bus is integrated to the national grid through three phase inverter to increase the continuity of power. The proposed HRES is working under classical-based supervisory control algorithm. According to the proposed algorithm, the wind is used the primary energy source to satisfy the load demands. The fuel cell is used to ensure long-term energy balance by using the hydrogen technology. The battery is utilized as a backup and high energy density device to keep the DC-bus voltage constant. The performance of the HRES is verified under real-world record of wind speed and load variations for the twenty five households at Islamabad, Pakistan. Matlab/Simulink results are provided to show the right performance of the proposed system in terms of load tracking, voltage regulation, and grid stability.

Performance of grid-integrated photovoltaic/fuel cell/ electrolyzer/battery hybrid power system

Integration of different energy sources and power converters is required to meet the load demands adequately under various natural conditions. This research work focuses on the hybrid power system combining renewable energy sources, namely, a photovoltaic (PV) array and a solid oxide fuel cell (SOFC) and a hybrid energy storage system, i.e., a battery bank and hydrogen storage tanks in the proposed architecture. The complete layout is connected to the national grid via power electronics converters to enhance the continuity and reliability of power. In the proposed system, the PV is taken as the primary energy source to satisfy the load demands. The fuel cell and electrolyzer are added to ensure long-term energy balance by using the hydrogen technology. The battery is utilized as a high energy density device to keep the DC-bus voltage constant. The dynamic behaviour of the proposed system is checked under different solar radiation, temperature and load conditions for the simulation of 24 Hrs. The proposed system exhibits excellent performance in terms of grid stability and voltage regulation. All the energy sources and their controllers are designed in Matlab/Simulink.

Adaptive control paradigm for photovoltaic and solid oxide fuel cell in a grid-integrated hybrid renewable energy system

The hybrid power system (HPS) is an emerging power generation scheme due to the plentiful availability of renewable energy sources. Renewable energy sources are characterized as highly intermittent in nature due to meteorological conditions, while the domestic load also behaves in a quite uncertain manner. In this scenario, to maintain the balance between generation and load, the development of an intelligent and adaptive control algorithm has preoccupied power engineers and researchers. This paper proposes a Hermite wavelet embedded NeuroFuzzy indirect adaptive MPPT (maximum power point tracking) control of photovoltaic (PV) systems to extract maximum power and a Hermite wavelet incorporated NeuroFuzzy indirect adaptive control of Solid Oxide Fuel Cells (SOFC) to obtain a swift response in a grid-connected hybrid power system. A comprehensive simulation testbed for a grid-connected hybrid power system (wind turbine, PV cells, SOFC, electrolyzer, battery storage system, supercapacitor (SC), micro-turbine (MT) and domestic load) is developed in Matlab/Simulink. The robustness and superiority of the proposed indirect adaptive control paradigm are evaluated through simulation results in a grid-connected hybrid power system testbed by comparison with a conventional PI (proportional and integral) control system. The simulation results verify the effectiveness of the proposed control paradigm.

Indirect adaptive soft computing based wavelet-embedded control paradigms for WT/PV/SOFC in a grid/charging station connected hybrid power system

This paper focuses on the indirect adaptive tracking control of renewable energy sources in a grid-connected hybrid power system. The renewable energy systems have low efficiency and intermittent nature due to unpredictable meteorological conditions. The domestic load and the conventional charging stations behave in an uncertain manner. To operate the renewable energy sources efficiently for harvesting maximum power, instantaneous nonlinear dynamics should be captured online. A Chebyshev-wavelet embedded NeuroFuzzy indirect adaptive MPPT (maximum power point tracking) control paradigm is proposed for variable speed wind turbine-permanent synchronous generator (VSWT-PMSG). A Hermite-wavelet incorporated NeuroFuzzy indirect adaptive MPPT control strategy for photovoltaic (PV) system to extract maximum power and indirect adaptive tracking control scheme for Solid Oxide Fuel Cell (SOFC) is developed. A comprehensive simulation test-bed for a grid-connected hybrid power system is developed in Matlab/Simulink. The robustness of the suggested indirect adaptive control paradigms are evaluated through simulation results in a grid-connected hybrid power system test-bed by comparison with conventional and intelligent control techniques. The simulation results validate the effectiveness of the proposed control paradigms.

PV based PHEVs smart charging station facility

The widespread applications of plug-in hybrid electric vehicles (PHEVs) established that there will be a massive inrush of PHEVs by the end of this century. There is a rising risk that this anticipation in the number of PHEVs will impose an extra burden in demand, especially at peak times and, therefore, threaten the stability of existing power grids. To satisfy the additional load of PHEVs, a smart charging station (CS) facility based on PV output power sensing due to the variation in solar irradiance and temperature is presented in this paper. The power required to charge the PHEVs is effectively managed from grid-connected photovoltaic (PV) generation. To confirm the optimal utilization of available power, charging time and grid stability, five possible switching modes have been considered for different interaction among the PHEVs, PV and the grid. Simulation results confirm the effectiveness of the proposed CS facility. The proposed CS and their controllers are designed in MATLAB/Simulink.

Fuel Cell/Electrolyzer/Ultra-capacitor hybrid power system: Focus on integration, power control and grid synchronization

Solid Oxide Fuel Cell (SOFC) is considered a promising green power source and offers various benefits such as modularity, high efficiency and cogeneration options. Unfortunately, the slow dynamics and gas starvation problems are the demerits of SOFC. Due to which the SOFC fails in providing fast response and also face load following problems. However, an integration of SOFC with complementary device such as an Ultra-capacitor (UC) can solve these problems. This paper presents an integration and power control of hybrid power system combining a SOFC stack, an Electrolyzer (ELZ) and an energy storage system in the form of hydrogen tanks and an UC module. A dynamic power flow controller is designed which supervised and managed all the energy sources and power converters to maximize the use of SOFC/ELZ/UC and reduce burden on the grid. According to the strategy, the SOFC is the used as the prior energy source. The UC is utilized as a complement and/or backup device to cover the slow dynamics of the SOFC during transient, while the ELZ is used as a dump load to generate hydrogen for SOFC during surplus power. The proposed system is synchronized to the grid through power electronic converters to enhance the reliability and continuity of power. The performance of the proposed system is investigated under real-world record of load conditions. Matlab/Simulink results are presented to verify the effectiveness of the proposed system interms of load tracking, power transfer, voltage regulation and grid synchronization.

A Road to Wind Based PHEVs Smart Charging Station

The introduction of Plug-in Hybrid Electric Vehicles (PHEVs) in the transportation sector has facilitated the public in terms of reducing fossil fuels consumption and pollution problems. However, the growing popularity of PHEVs create new technical problems in the power system in terms of grid stability and upgradation of distribution transformers. To balance the extra load of PHEVs, a smart charging station based on wind output power sensing is presented in this paper. The required charging of PHEVs batteries is coordinately satisfied from wind and/or grid integrated wind generation. The operation of the proposed smart charging station is effectively completed in seven possible different interactions among the PHEVs, wind and the grid via different switching modes. Matlab/Simulink results are presented to confirm the effectiveness of the proposed charging station.