Performance Of Hybrid Power System Research Articles

Research on the Working Performance of UAV Hybrid Power System Based on Mission Profile

Currently, UAVs can be divided into two main types based on the type of power unit, fuel-powered UAVs and electrically powered UAVs. Most drones that are generally smaller and lighter in weight are electrically powered; while larger drones are usually fuel-powered. Both have their advantages and disadvantages, with fuel-powered drones being highly polluting and noisy, while electric drones usually have a shorter range. Fuel-powered UAVs are noisy and polluting, while electrically powered UAVs are usually shorter. The hybrid system combines the advantages of both and reduces pollution while ensuring a longer range. In this paper, an oil-electric hybrid power system for a tilt-rotor UAV is studied, a mathematical model of the hybrid power system is built, and the performance of the hybrid power system is studied and analyzed based on the mission profile. The mission profile of the UAV is determined, and the UAV demand power curve under this mission profile is given. The overall performance of the oil-electric hybrid power system is simulated and calculated. The results show that the oil-electric hybrid power system meets the power demand of the tilt-rotor UAV under the mission profile given in this paper, and can work normally within the full envelope.

Numerical investigation on hydrogen-diesel dual-fuel engine improvements by oxygen enrichment

Hydrogen-diesel dual fuel (HDDF) technology is one approach available to improve the performance and reduce carbon-based emissions of compression ignition (CI) engines. Unfortunately, when operated at partial and low loads, HDDF engine configurations suffer from poor fuel utilization, combustion efficiency and ignition delay. As partial load application is increasingly important to performance of hybrid power systems, this paper explores the use of oxygen enrichment to improve HDDF performance outside of conventional load applications.In this paper, a numerical model was first developed and validated for HDDF combustion using experimental data. This model was subsequently applied to study the influences of oxygen enrichment on engine performance and emission characteristics. Furthermore, the Exhaust Gas Recirculation (EGR) was implemented as a secondary control for NOx emission reduction. For this configuration the results showed that oxygen enrichment (between 21% and 27% by volume) into the intake manifold led to an improved combustion efficiency and reduced carbon-based emissions. The brake thermal efficiency (BTE) increased by 1.6% and the brake specific energy consumption decreased by 4%. Across the emissions spectrum, soot emission reduced by 72%, whereas NOx emission increased by 63% without using the EGR technique. By combining oxygen enrichment and EGR strategies, a considerable reduction of 79% in NOx and an increase of 2.6% in BTE was observed for the oxygen concentration of 27% and EGR rate of 24% compared to a conventional HDDF operation with 45% HES ratio.

Nonlinear backstepping controller design for bridge‐type fault current limiter to enhance the transient performance of hybrid power systems

Nonlinear backstepping controller design for <scp>bridge‐type</scp> fault current limiter to enhance the transient performance of hybrid power systems

Optimal PI controller of DVR to enhance the performance of hybrid power system feeding a remote area in Egypt

This article proposes optimal PI controllers of Dynamic Voltage Restorer (DVR) to enhance the performance of stand-alone hybrid renewable energy system that is feeding a new community located in Egypt. The hybrid system includes three renewable energy sources, namely, solar PV cells, wind turbines based permanent magnet synchronous generator and fuel cells. These three sources are connected to a common DC link by three boost converters, one for each source. The common DC link is integrated to the AC loads via DC/AC inverter. The optimal size of the three proposed renewable sources is obtained using the HOMER software package. The main contribution of this study is designing optimal PI controller for DVR for enhancing the performance of a hybrid PV-wind-fuel cell. Two PI controllers are used to regulate the IGBT pulses of the voltage source inverter (VSI) driving DVR by adjusting the D-Q axes voltage signals. The D-Q axis components of the load voltage represent the inputs to the two PI controllers respectively. While the D-Q axis voltage signals driving the IGBT pulses of the DVR-VSI IGBT are the outputs of the two PI controllers respectively. A Cuckoo Search (CS), as an optimization technique is used for determining the optimal PI control parameters used to drive the DVR at different operating conditions. To validate the effectiveness of the DVR based PI-CS control, four test scenarios are investigated includes (three phase fault, sag, swell and unbalance voltage conditions). The enhancement of the system performance is achieved through improving the voltage, the current and the power waveforms for each source, improving the dynamic performance of the wind turbine generator and keeping the continuous operation of the three sources during faulty conditions. The proposed system is modeled using MATLAB/Simulink.

A process integration approach for design of hybrid power systems with energy storage

Selection of energy storage technology in hybrid power systems (HPS) is vital due to the unique advantages and capabilities offered by different storage technologies. For an optimal operation, the efficient and economical storage system for an HPS should be selected. This work introduces a new systematic generic framework to determine the most cost-effective storage technology for an HPS. A Power Pinch Analysis tool called the AC/DC modified storage cascade table has been developed to optimise the HPS by considering various storage technologies. The economics of the various types of storage modes was analysed, taking into account the associated energy losses, among others. The method was applied to two case studies with different power trends to evaluate the effect of storage efficiencies and storage form on the performance of HPS. A superconducting magnetic storage system of 26.12 kWh capacity, that gives an investment payback period of 3.6 years, is the most cost-effective storage technology for the small-scale household system in Case Study 1. For the large-scale industrial application presented in Case Study 2, the Lead–Acid battery with a capacity of 15.38 MWh gives the lowest payback period (1.43 years).

Modeling pumped hydro storage with the micropower optimization model (HOMER)

Most renewable energy technologies suffer from an intermittent characteristic due to the diurnal and seasonal patterns of the natural resources needed for power generation; therefore, a complementary energy storage system must be considered. The pumped hydropower plant is a suitable alternative to consider as an energy storage device for hybrid systems. The hybrid optimization model for electric renewables (HOMER) optimization model is widely used around the globe for designing, comparing, or evaluating the performance of hybrid power systems, but it does not include an explicit component to model a pumped hydropower facility. This paper describes a method for representing a pumped hydropower plant by creating an equivalent battery in HOMER, and the procedure was accompanied by a detailed example. An additional example of a wind-hydro hybrid power system with controlled parameters is presented to validate the method. The results support that the procedure explained in this paper adequately represents the pumped hydropower plant as an equivalent battery.

가스터빈의 규모별 성능차이를 고려한 고체산화물 연료전지/가스터빈 하이브리드 시스템의 성능해석

This study analyzes the performance of hybrid power systems combining a solid oxide fuel cell (SOFC) and a gas turbine (GT). Research focus is given to the influence of the size-dependent gas turbine performance on hybrid system performance. Three hybrid systems adopting different gas turbines (kW, sub-MW, multi-MW classes) are designed. As the gas turbine power increases (i.e. as the gas turbine performance enhances), the gas turbine power portion increases and the hybrid system efficiency increases. The hybrid system shows efficiency improvement over the SOFC only system even in the case where the gas turbine net power is nearly zero. The increase of gas turbine pressure ratio contributes to the net hybrid system power output in all of the three cases, while system efficiency is almost independent on the pressure ratio.

Design performance analysis of pressurized solid oxide fuel cell/gas turbine hybrid systems considering temperature constraints

This study presents critical aspects and their influence on the performance of hybrid power systems combining a pressurized solid oxide fuel cell (SOFC) and a gas turbine (GT). Two types of hybrid system configurations with internal and external reforming have been analyzed. In order to examine the effect of matching between the fuel cell temperature and the turbine inlet temperature on the hybrid system performance, we considered air bypass after the compressor as well as additional fuel supply to the turbine side. This study focuses on the limitation of the temperature difference at the fuel cell stack and its influence on the performances of the two hybrid systems. Performances of the hybrid systems are also compared with those of simple SOFC systems, and the extent of performance enhancement is evaluated. The system with internal reforming gives better efficiency and power capacity for all design conditions than the system with external reforming under the same constraints. Its efficiency gain over the SOFC only system is considerable, while that of the system with external reforming is far less. As the temperature difference at the cell becomes smaller, the system performance generally degrades. The system with internal reforming is less influenced by the constraint of the cell temperature difference.

Hybrid wind/PV/diesel hybrid power systems modeling and South American applications

This paper presents an applications case study and comparison of performance results between two computational models for simulating the performance of hybrid power systems. The first model, HYBRID2, was developed at the University of Massachusetts under National Renewable Energy Laboratory (NREL) sponsorship. The second model, SOMES, was developed at Utrecht University in the Netherlands. Both models have been designed to predict the technical and economical (life cycle cost) performance of hybrid power plants that typically might be comprised of renewable energy sources, a battery bank, and a diesel generator. A South American (Brazil) based hybrid power system used to power a remote telecommunications system was used for the applications case study. A final system configuration be used as a basis for model prediction comparison was established as a result of HYBRID2 parametric evaluation. Both codes yielded similar performance results, and this work points out that the predicted performance discrepancies are due basically to different subcomponent models and differences in control strategy. The generalized nature of this work is intended to be of interest to engineers involved with the design and analysis of hybrid power systems.