| 英文摘要 | With the industrialization going on around the world, the consumption of energy is getting greater and greater. As a result, traditional energy sources are being used up. At the same time, the pollution caused by the emissions is becoming worse and worse. In order to delay the breakout of the energy crisis and alleviate the pollution, many countries devote great efforts to searching and making use of all kinds of new energy resources. Since fuel cell boasts of many ingenious features, such as start-up at low temperature, high power density, long cell and stack life, and environment friendliness, it is now under intensive development by many governments, manufacturers and researchers. Though researchers have made progress in fuel cell modeling and controlling, as fuel cell is a multi-variable, strongly coupling and non-linear system, its dynamic and static performance are affected by many factors both from outer environment and inner parameters, so it is a challenging task to manage the output power of fuel cell. The main contributions of this thesis include: 1, In order to make best use of reactant gases and improve the quality of electric power from fuel cell, a hybrid power source is put forward which consists of fuel cell and assistant power source. On the basis of this idea, a fuel cell power management system is constructed . 2, A fuel cell testbench is build up including a fuel cell stack, a humidifier, two flow meters, a temperature control system, a power management system and a load system. 3, A theoretical model of a PEM fuel cell fuel cell system is proposed. 4, The topologies of the DC/DC and the current regulator are constructed and the circuits for these two components are also designed. 5, Two control strategies are proposed, and correspondingly, many kinds of controllers are designed according to the two strategies and the characteristic of every component in the fuel cell system. Subsequent tests show that under the control of these controllers, the flows of reactant gases could track the stack current in low frequency and insulate from the stack current in high frequency. |
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