Research of the Power Control for a MCFC/GT Hybrid System

2013 ◽  
Vol 860-863 ◽  
pp. 2596-2599
Author(s):  
Fan Yang ◽  
Hua Xue ◽  
Hao Li

Molten carbonate fuel cell/ gas turbine hybrid power system (MCFC/GT) output power should real-time response the demand of load. The auto-tuning ZieglerNichols tuned PI controller (AZNPIC) as a feedback controller for power corrective action is added to the hybrid power system. The optimal setpoints and feed forward control inputs of the controller are given by Multi-output Support Vector Machine Regression (MSVR) predictor for the hybrid system. Simulation results show that the power of hybrid system can be effectively close to the desired setpoints based on the control method.

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2192 ◽  
Author(s):  
Chen Yang ◽  
Kangjie Deng ◽  
Hangxing He ◽  
Haochuang Wu ◽  
Kai Yao ◽  
...  

The research on the control strategy and dynamic characteristics of the Molten Carbonate Fuel Cell-Micro Gas Turbine (MCFC-MGT) hybrid power system has received much attention. The use of the Hardware-In-the-Loop Simulation (HILS) method to study the MCFC-MGT hybrid power system, where the MCFC is the model subsystem and the MGT is the physical subsystem, is an effective means to save development cost and time. The difficulty with developing the MCFC-MGT HILS system is the transfer of the mass, energy, and momentum between the physical subsystem and the model subsystem. Hence, a new Simulation–Stimulation (Sim–Stim) interface model of the MCFC-MGT HILS hybrid power system to achieve a consistent mass, energy, and momentum with the prototype system of the MCFC-MGT hybrid power system is proposed. In order to validate the Sim–Stim interface model before application in an actual system, both a real-time model of the MCFC-MGT hybrid power system and the MCFC-MGT HILS hybrid power system based on the Sim–Stim interface model were developed in the Advanced PROcess Simulation (APROS) platform. The step-up and step-down of the current density, which were strict for the Sim–Stim interface model, were studied in these two models. The results demonstrated that the Sim–Stim interface model developed for the MCFC-MGT HILS hybrid power system is rapid and reasonable.


2020 ◽  
Vol 8 (2) ◽  
pp. 74 ◽  
Author(s):  
Hyeonmin Jeon ◽  
Kido Park ◽  
Jongsu Kim

In order to secure the safe operation of the ship, it is crucial to closely examine the suitability from the design stage of the ship, and to set up a preliminary review and countermeasures for failures and defects that may occur during the construction process. In shipyards, the failure mode and effects analysis (FMEA) evaluation method using risk priority number (RPN) is used in the shipbuilding process. In the case of the conventional RPN method, evaluation items and criteria are ambiguous, and subjective factors such as evaluator’s experience and understanding of the system operate a lot on the same contents, resulting in differences in evaluation results. Therefore, this study aims to evaluate the safety and reliability for ship application of the reliability-enhanced fuel cell-based hybrid power system by applying the re-established FMEA technique. Experts formed an FMEA team to redefine reliable assessment criteria for the RPN assessment factors severity (S), occurrence (O), and detection (D). Analyze potential failures of each function of the molten-carbonate fuel cell (MCFC) system, battery system, and diesel engine components of the fuel cell-based hybrid power system set as evaluation targets to redefine the evaluation criteria, and the evaluation criteria were derived by identifying the effects of potential failures. In order to confirm the reliability of the derived criteria, the reliability of individual evaluation items was verified by using the significance probability used in statistics and the coincidence coefficient of Kendall. The evaluation was conducted to the external evaluators using the reestablished evaluation criteria. As a result of analyzing the correspondence according to the results of the evaluation items, the severity was 0.906, the incidence 0.844, and the detection degree 0.861. Improved agreement was obtained, which is a significant result to confirm the reliability of the reestablished evaluation results.


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.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Chunyou ZHANG ◽  
Lihua WANG

Because the load of the oil beam pumping unit driven by pure electric motor changes sharply during operation, the power of the driving motor does not match and the energy efficiency is low. In this paper, a new type of wind-driven hydro-motor hybrid power system is proposed. The motor and the hydraulic motor are jointly driven, and the energy is recovered by a hydraulic pump with controllable displacement, so that the speed of the driving motor is relatively stable. In order to control the fan speed and keep up with the drastic changes of the outside wind speed, a control strategy of hybrid power system based on wind speed feed-forward compensation is proposed. Through simulation and experimental results, the following conclusions can be drawn: to begin with, the mathematic model is proved to be effective; next, simulation studies show that the proposed feed-forward control method can improve the response rate as well as reduce the response lag. This research can be a reference for the application of the feed-forward control method on the hybrid power system of beam pumping unit.system.


Author(s):  
Mehdi Mehrpooya ◽  
Parimah Bahramian ◽  
Fathollah Pourfayaz ◽  
Hadi Katooli ◽  
Mostafa Delpisheh

Abstract The production of liquefied natural gas (LNG) is a high energy-consuming process. The study of ways to reduce energy consumption and consequently to reduce operational costs is imperative. Toward this purpose, this study proposes a hybrid system adopting a mixed refrigerant for the liquefaction of natural gas that is precooled with an ammonia/water absorption refrigeration (AR) cycle utilizing the exhaust heat of a molten carbonate fuel cell, 700°C and 2.74 bar, coupled with a gas turbine and a bottoming Brayton super-critical carbon dioxide cycle. The inauguration of the ammonia/water AR cycle to the LNG process increases the cooling load of the cycle by 10%, providing a 28.3-MW cooling load duty while having a 0.45 coefficient of performance. Employing the hybrid system reduces energy consumption, attaining 85% overall thermal efficiency, 53% electrical efficiency and 35% fuel cell efficiency. The hybrid system produces 6300 kg.mol.h−1 of LNG and 146.55 MW of electrical power. Thereafter, exergy and sensitivity analyses are implemented and, accordingly, the fuel cell had an 83% share of the exergy destruction and the whole system obtained a 95% exergy efficiency.


Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim

Owing to the increasing consumption of fossil fuels and emission of greenhouse gases, interests in highly efficient and low carbon emitting power systems are growing fast. Several research groups have been suggesting advanced systems based on fuel cells and have also been applying carbon capture and storage technology to satisfy the demand for clean energy. In this study, the performance of a hybrid system, which is a combination of a molten carbonate fuel cell (MCFC) with oxy-combustion carbon capture and an indirectly fired micro gas turbine (MGT) was predicted. A 2.5MW MCFC system that is used in commercial applications was used as the reference system so that the results of the study could be applicable to practical situations. The ambient pressure type hybrid system was modeled by referring to the design parameters of an MGT that is currently being developed. A semi-closed type design characterized by flow recirculation was adopted for this hybrid system. A part of the recirculating gas is converted into liquefied carbon dioxide and captured for storage at the carbon separation unit. Almost 100% carbon dioxide capture is possible with this system. In these systems, the output power of the fuel cell is larger than in the normal hybrid system without carbon capture because the partial pressure of carbon dioxide increases. The increased cell power partially compensates for the power loss due to the carbon capture and MGT power reduction. The dependence of net system efficiency of the oxy-hybrid on compressor pressure ratio is marginal, especially beyond an optimal value.


Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim

Owing to the increasing consumption of fossil fuels and emission of greenhouse gases, interests in highly efficient and low carbon emitting power systems are growing fast. Several research groups have been suggesting advanced systems based on fuel cells and have also been applying carbon capture and storage technology to satisfy the demand for clean energy. In this study, the performance of a hybrid system, which is a combination of a molten carbonate fuel cell (MCFC) with oxy-combustion carbon capture and an indirectly fired micro gas turbine (MGT), was predicted. A 2.5 MW MCFC system that is used in commercial applications was used as the reference system so that the results of the study could be applied to practical situations. The ambient pressure type hybrid system was modeled by referring to the design parameters of an MGT that is currently being developed. A semi-closed type design characterized by flow recirculation was adopted for this hybrid system. A part of the recirculating gas is converted into liquefied carbon dioxide and captured for storage at the carbon separation unit (CSU). Almost 100% carbon dioxide capture is possible with this system. In these systems, the output power of the fuel cell is larger than in the normal hybrid system without carbon capture because the partial pressure of carbon dioxide increases. The increased cell power partially compensates for the power loss due to the carbon capture and MGT power reduction. The dependence of net system efficiency of the oxy-hybrid on compressor pressure ratio is marginal, especially beyond an optimal value.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2781
Author(s):  
Yue Zhou ◽  
Hussein Obeid ◽  
Salah Laghrouche ◽  
Mickael Hilairet ◽  
Abdesslem Djerdir

In order to improve the durability and economy of a hybrid power system composed of a battery and supercapacitors, a control strategy that can reduce fluctuations of the battery current is regarded as a significant tool to deal with this issue. This paper puts forwards a disturbance rejection control strategy for a hybrid power system taking into account the degradation of the battery. First, the degradation estimation of the battery is done by the model-driven method based on the degradation model and Cubature Kalman Filter (CKF). Considering the transient and sinusoidal disturbance from the load in such a hybrid system, it is indispensable to smooth the behavior of the battery current in order to ensure the lifespan of the battery. Moreover, the constraints for the hybrid system should be considered for safety purposes. In order to deal with these demands, a cascaded voltage control loop based on a super twisting controller and proportional integral controller with an anti-windup scheme is designed for regulating the DC bus voltage in an inner voltage loop and supercapacitors’ voltage in an outer voltage loop, respectively. The specific feature of the proposed control method is that it operates like a low-pass filter so as to reduce the oscillations on the DC bus.


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