System design and control algorithm for a 150W portable fuel cell power pack

Fuel cell has a lot of advantages like zero emission, high efficiency, little noise, and extremely low vibration. So, it is considered as a suitable alternative source for the portable power supply. However, it needs to be made up for the weak points such as high cost and slow dynamic response. As a representative useful solution to remedy fuel cell's shortcomings, battery is being utilized in various hybrid systems. In this paper, five fuel cell-battery hybrid system structures are analyzed in order to find the optimal structure for a 150W portable fuel cell power pack. Then, each main part is designed to achieve compact size, simple control, high efficiency, and low cost. Also, this paper suggests an automatic mode change algorithm considering the state of fuel cell, battery, and load. Experimental results show stable mode changes and the performance of a 150W prototype.