Research And Implement On Control Of Miniature Fuel Cell Hybrid Power System

With the large numbers of energy consumption caused by social development, traditional energy sources can not meet human's requirements, particularly in today when sustainable development strategy and protecting environment are proposed. Exploiting and using new energy source has become an important topic. Fuel cell is a new environment-friendly and high efficiency energy source. The mechanism is that water, carbon dioxide and the current are generated by chemical reactions between the fuel and oxygen. In the wild environment without electricity, as a clean and efficient power generating equipment, fuel cell is the best choice for wild power supply. Therefore fuel cell has broad application prospects in the aspect of national defense, electric power, automotive, mobile power supply, submarines, aviation and aerospace technology.Beginning with control of a portable fuel cell power generating device, how to control the mixing of secondary power supply and fuel cell stack is proposed in this dissertation. In the system, the output voltage of micro fuel cell (direct methanol fuel cell) is decided by the concentration, temperature and flow of fuel (methanol). Therefore, the output voltage is instability. Although controlling these parameters can make the output voltage stable, it is also difficult to achieve practical application requirements. So it is necessary to use the secondary power supply to assist fuel cell. The secondary power supply of system uses super capacitor. The fuel cell initially charges to super capacitor, the internal storage capacity in the super capacitor reaches a certain target and then the super capacitor discharges to the device, when the super capacitor is low power, the fuel cell charges to the super capacitor again, so the output voltage can be controlled in a certain range, guaranteed device worked normally.At the same time, in order to facilitate the user to monitor the state parameters of hybrid system in the real-time, a host computer monitoring system is developed to work with the system. When the system is running, the whole hybrid system operating parameters are sent to the host computer, the user can know system control state in real-time. The system can also provide a good optimization control strategy for distribution of energy, and save some useful parameters based on the user's requirements.Finally, this fuel cell hybrid power system is tested. The test results show that this system can supply power to the low power devices for a long time. Fuel (methanol) is relatively easy to get, small size and easy to carry, so it is a very promising new energy device. The study has very important significance on the development and utilization of new energy technologies.