Micro Gas Turbine/Renewable Hybrid Power System for Distributed Generation: Effects of Ambient Conditions on Control Strategy

Author(s):  
Ma Shixi ◽  
Dengji Zhou ◽  
Huisheng Zhang ◽  
Zhenhua Lu

Hybrid power systems are becoming popular for remote areas due to lower operating cost and green gas emission. Most of these systems are used in remote or harsh environments, so the effect of ambient conditions on system operation is an important factor that should not be ignored. In this paper, the system referred is a domestic hybrid power system including a renewable energy conversion device (Photovoltaic, PV), a traditional energy conversion device (Micro Gas Turbine, MGT) and an electrochemical energy storage unit (batteries). A numerical model, which considers the effect of ambient conditions on the whole system, has been developed. Model Predictive Control (MPC) strategy has been applied to the analysis of power management. The control strategy includes the objective of minimizing system costs, while considering real operational constraints of the plants. Performances attainable with the MPC strategy have been evaluated in comparison with a standard Rule Based Control logic (RBC), by means of costs and efficiency parameters of the system. The effects of ambient conditions on system operation based on MPC-based strategy are evaluated. The simulation has been carried out for the summer and winter periods in four places with different climate in China. Results show that a lower cost of primary fossil energy is found by using the MPC strategy. This is mainly due to the increased use of renewable energy sources by considering the future load. An obvious effect of ambient conditions on control process is observed. A significant improvement for the whole year in efficiency of the system, especially in high latitude cold regions with larger temperature difference from the design condition, is achieved by considering the ambient conditions. The highest reduction of fuel consumption reaches to 4% during the winter. As a result, the effect of the ambient conditions in some areas must be taken into account for control system design.

Volume 3 ◽  
2004 ◽  
Author(s):  
Tae Won Song ◽  
Jeong L. Sohn ◽  
Jae Hwan Kim ◽  
Tong Seop Kim ◽  
Sung Tack Ro ◽  
...  

Performance of a solid oxide fuel cell (SOFC) can be enhanced by converting thermal energy of its high temperature exhaust gas to mechanical power using a micro gas turbine (MGT). A MGT plays also an important role to pressurize and warm up inlet gas streams of the SOFC. Performance behavior of the SOFC is sensitively influenced by internal constructions of the SOFC and related to design and operating parameters. In case of the SOFC/MGT hybrid power system, internal constructions of the SOFC influence not only on the performance of the SOFC but also on the whole hybrid system. In this study, influence of performance characteristics of the tubular SOFC and its internal reformer on the hybrid power system is discussed. For this purpose, detailed heat and mass transfer with reforming and electrochemical reactions in the SOFC are mathematically modeled and their results are reflected to the performance analysis. Effects of different internal constructions of the SOFC system and design parameters such as current density, recirculation ratio, fuel utilization factor, and catalyst density in internal reformer on the system performance are investigated and, as a result, some guidelines for the choice of those parameters for optimum operations of the SOFC/MGT hybrid power system are discussed.


Author(s):  
Hongliang Hao ◽  
Huisheng Zhang ◽  
Shilie Weng ◽  
Ming Su

Fuel cells have been revealed to be a very attractive power generation system, promising highly efficient electricity generation and very low environmental impact. The integration of micro turbines and high-temperature fuel cells has been proposed in recent years as an extremely efficient solution for power generation. A molten carbonate fuel cell / micro gas turbine (MCFC/MGT) hybrid power system has theoretically demonstrated that it can achieve higher thermal efficiency than other conventional power generation systems. To understand operation characteristics of the MCFC/MGT hybrid power system, it is essential to analyze influence of operating and design parameters on its performance. Based on an existing 50KW MCFC stack, a steady-state thermodynamic model for MCFC/MGT hybrid power system is developed on the IPSEpro simulation platform and applied to a performance analysis. The characteristics under off-design and design condition for hybrid power system were also analyzed.


2018 ◽  
Author(s):  
Lin Liu ◽  
Zhenda Hu ◽  
Rong Ye ◽  
Zhangsui Lin ◽  
Xiaodong Yang ◽  
...  

2017 ◽  
pp. 1438-1460 ◽  
Author(s):  
Vincent Anayochukwu Ani

Telecommunications industry requires efficient, reliable and cost-effective hybrid power system as alternative to the power supplied by diesel generator. This paper proposed an operational control algorithm that will be used to control and supervise the operations of PV/Wind-Diesel hybrid power generation system for GSM base station sites. The control algorithm was developed in such a way that it coordinates when power should be generated by renewable energy (PV panels and Wind turbine) and when it should be generated by diesel generator and is intended to maximize the use of renewable system while limiting the use of diesel generator. Diesel generator is allocated only when the demand cannot be met by the renewable energy sources including battery bank. The developed algorithm was used to study the operations of the hybrid PV/Wind-Diesel energy system. The control simulation shows that the developed algorithm reduces the operational hours of the diesel generator thereby reducing the running cost of the hybrid energy system as well as the pollutant emissions. With the data collected from the site, a detailed economic and environmental analysis was carried out using micro power optimization software homer. The study evaluates savings associated with conversion of the diesel powered system to a PV/Wind-Diesel hybrid power system.


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