Hot Topic: Fuel Cell Model

Hot Topic: Fuel Cell Model

Fuel Cell is an Entity of Modern Grids

Development of information and communication technology helps real-time management and control of distributed energy resources (DERs) connected to the grid. At present, utilities are interested to modernize their power grid through the advancement of smart grid.

A smart grid is an electrical grid which extensively uses the digital communication to manage energy entities including DERs, electrical vehicles, and smart energy meters to minimize the mismatch between generation and load within the grid.

The development of the fuel cell began with a human effort towards space exploration. The electricity needs of all the commander vehicles in the Apollo project in the 60s’ and 70s’ were provided by fuel cells. The justification was simple and clear. The rocket motor in the vehicles took pure hydrogen and oxygen as fuel, which were the same chemicals necessary for the operation of the fuel cells on board. Moreover, the by-product water was used for drinking and humidifying the atmosphere of the space capsule [1]. Then, the technology found a completely different application, electric vehicle (EV). The amount of EVs connected to the smart grid is believed to be large in the near future as EVs are considered as a greener solution for the carbon emission issue. The recent research and developments on the fuel cell electric vehicle (FCEV) have attracted the vehicular industry. Fuel cells are devices that utilize the electrochemical process to convert chemical energy in a fuel to electrical energy. The produced electrical energy can be used to power electric vehicles, electronic devices, house and the excess energy can be delivered to the grid. Many different types of fuel cells can be constructed from different chemical reactions. In general, those fuel cells can be categorized according to the electrolyte used in the cell. However, for vehicular technology, the usual choice is polymer electrolyte membrane fuel cells (PEMFC). Apart from the emerging FCEV market, the biggest market for the PEM fuel cell is the application of back-up power supply for remotely located electronic outposts such as cell phone towers. Fuel cells also have an expanding presence in the indoor fork-lifter power pack application because of zero-emission characteristics. Conventional fuel such as natural gas can be converted to hydrogen with the necessary purity after reformation. This adds to the suitability of the technology in the diverse markets.

Another interesting application of the fuel cell is rural electrification.

A complete closed-loop pilot project based on fuel cell is built to electrify Stuart Island of Washington state. Solar panels are used to power an electrolyzer which makes hydrogen. Then, the hydrogen is used in fuel cells to produce dc current which is converted to ac current by an inverter to supply the loads [2].

The research and developments that take place at RTDS Technologies Inc. are always in line with advancements in the electrical industry. This time, we are proud to introduce the real-time simulation model of the PEMFC.

Operation of the Polymer Electrolyte Membrane Fuel Cell

The functional diagram of a polymer electrolyte membrane fuel cell (PEMFC) is shown in Figure 1. The anode and the cathode are separated by an electrolyte that is based on polymer electrolyte membrane.

fuel-cell-diagram

Figure 1 – Functional diagram of fuel cell

At the anode, a hydrogen molecule will decompose into two hydrogen ions (H+) and two electrons (e). Typically, a catalyst is used to boost the rate of reaction. Since the electrolyte behaves like a high resistance to the electrons and low resistance to the proton, the hydrogen ions will pass through the electrolyte while the electrons flow through the external load. At the Cathode, the oxygen ion (O2-) will combine with two hydrogen ion (H+) and form water (H2O) that will carry out the heat produced by the fuel cell reactions.

The RTDS Fuel Cell Model

The RTDS fuel cell model represents the PEM type fuel cell. In particular, this model attempts to depict the electrical aspect of a real fuel cell system known as ‘SR-12’ from a company named ‘Avista Labs’ (now ‘ReliON’). The fuel cell system is described further in [3, 4]. The draft icon of the model is shown in Figure 2. The model has two power system nodes namely Cathode and Anode. The model has three control inputs, which are the cell temperature (Tcell) in Celsius, the anode pressure (Pa) in atm, and cathode pressure (Pc) in atm. This model also requires the user to enter parameters such as charging capacitance per cell, cell area overall flow delay, rated voltage and current, and initial temperature and pressure values.

Fuel-cell-model-draft

Figure 2 – Draft icon of the fuel cell model in RTDS

The PEMFC model enriches our latest release of RSCAD software that is available on our website www.rtds.com. More information of the above fuel cell model can be found in the help file associated with the model. Should you have any questions, please do not hesitate to contact us at support@rtds.com.

Author: Arunprasanth Sakthivel
March, 2017

References

[1] K. R. Williams, “Francis Thomas Bacon. 21 December 1904-24 May 1992.” Biographical Memoirs of Fellows of the Royal Society, 39, pp 2-18, 1994.
[2] “Stuart Island Energy Initiative”, http://www.siei.org, accessed on March 18, 2017.
[3] J. M. Correa, F. A. Farret, L. N. Canha, and M. G. Simoes, “An electrochemical-based fuel-cell model suitable for electrical engineering automation approach,” Industrial Electronics, IEEE Transactions on, vol. 51, pp. 1103-1112, 2004.
[4] The Center for Fuel Cell Research and Applications, “ReliOn (formerly Avista Labs) Independence 1000 Model J32 OVERALL EXPERIENCE,” 2004.