Week 6 Fuel cell powered vehicle model

Study – Make a MATLAB model of fuel cell powered electric vehicle and comment on results.

Fuel cell is a device which converts chemical energy into electrical energy with some by products. Fuel cell provides high specific energy that can be used for long range, but they are poor in specific power so they cannot sustain high accelerations. Fuel cell produces energy from hydrogen and oxygen, these can remain in cell until they needed.

Fuel cell application lies in large electricity plant and small devices like mobile, laptop, etc. Fuel cell can be used in vehicle with engine. For that type of vehicle fuel cell will provide energy for longer range and engine will provide energy in high acceleration. Fuel cell and engine is configured with a control system, which decides time of energy distribution.

Model description –

DC-DC converter -

For this study we made electric vehicle model which is powered by fuel cell. We are assuming vehicle equivalent to resistance value in ohm. This model has a feedback system, which controls fuel flow rate.

We started with fuel cell block, which represents a generic model parameterized to represent most popular types of fuel cell stacks. It has three output port – information, negative terminal and positive terminal and it has only one input terminal which takes signal which controls fuel flow rate.

Fuel Cell parameter -

Fuel cell in port is connected with saturated block. Fuel rate selector block connected with switch and takes input from signal builder, which has values of fuel rate in litre per meter. Fuel rate selector block takes signal from flow rate regulator block which is a feedback signal.

Fuel Rate(lt/m)

Fuel cell terminals are connected with DC-DC converter which has implemented with controlled also. Further, DC-DC has connected with voltage and current measurement source. Ammeter is connected with RL load which can be considered equivalent to load, which vehicle requires.

M port of fuel cell gives information which can be used with bus selector and further, signal can be displays using scope block.

Results –

We selected for signal from bus selector- Fuel flow rate(lt/m), Utilization of oxygen and Hydrogen, air and fuel consumption and stack efficiency.

Fuel flow rate increases exponentially during first 5second and after it, it increases linearly and attains maximum value-90, which is influenced with the values we gave using signal builder.

Oxygen utilization is constant which around 60% and hydrogen utilization is first decreases and after it increases. Stack consumption is increase exponentially and after some time it will be stable. Now look at stack efficiency decreases initially and after 70second it increase because it is influenced by fuel flow rate.

initially voltage decreases till 45V an then it increases and attains maximum value 55V, contrary current is increasing exponentially till 110A and further it decreases.