| With the development of the social economic and the acceleration of the progress of the urbanization, the problem of urban environmental pollution caused by the heavy traffic and the associated automobile exhaustion has been the burning issue for the large and medium-sized cities nowadays. The development of the urban public transportation, particularly the rail transit with the power of renewable energies, is an effective solution to solve the problems mentioned above. Among them, the new energy hybrid power tram based on the proton exchange membrane fuel cell (PEMFC) is a novel transportation tool with great application potential, which would be high efficiency and environmentally safe. So many countries have made great effort on the research and development of the application of this type of new energy hybrid power tram, which is the hot research issue of the modern tram technology.A novel hybrid power system topology for the modern power tram consisted of proton exchange membrane fuel cell (PEMFC) power system, super capactor storage system and PV/Li auxiliary power sytem was proposed. In order to enhance operating stability and improve energy utilization efficiency for the power tram, the PEMFC power system as the main power souce and the PV/Li hybrid power system as the auxiliary power source were focused on. The main contributions obtained in this dissertation are as follows.(1) A test platform for the prototype of 150kW PEMFC powered tram has been designed, and the structure and the control strategy of the integrated power system of the prototype has been optimum design. Based on the test for the individual PEMFC power system and the integrated locomotive prototype respectively, the characteristics of the PEMFC power system was analyzed.(2) The PEMFC steady-state impedance model based on the frequency response analysis (FRA) and the PEMFC integrated dynamic model which models the air delivery response, cathode/anode pressure control response and the current setpoint response have been built, which are used for the research of the steady-state and dynamic coupling characteristics between the PEMFC and the cascaded power converter. With the steady-state impedance model, a quantitative analysis method is proposed to estimate the output current ripple which indicates the steady-state coupling characteristics between the PEMFC and the cascaded power converter. This method can be used to guide the input filter design for the power converter in order to satisfy the output current ripple restriction for the PEMFC power module. Aiming to resolve the dynamic coupling problem caused by the dynamic response mismatch between PEMFC and the cascaded power converter, an I2V active control strategy for the cascaded converter which takes the PEMFC output current into consideration was proposed, and was verified with the simulation based on the proposed PEMFC integrated dynamic model.(3) Combined with the material optical properties of the modern photovoltaic panels, a computation method which quantizes the influence of the effect of the anti-reflection interference and crystalline-Si surface texturing to the absorption efficiency of the incidence irradiance was proposed. Besides, based on the decoupling of the transcendental equation of the electrical characteristics of the photovoltaic module with the Special Transfer Function operator, a novel PV cell model coupling the optical and thermal characteristics was proposed, which can be used to assist the simulation for the proposed PV/Li hybrid power system.(4) A novel PV/Li energy storage power system topology based on the non-balancing cell management (NBCM) was proposed, and could be utilized to provide auxiliary power for the hybrid power tram, which would optimize the energy utilization efficiency and improve the operating stability of the auxiliary power system of the power tram. Combined with the proposed photovoltaic model, the developed prototype was verified by the simulation and experiment.(5) The individual module of NBCM PV/Li energy storage power system was designed optimally. A novel two-stage control unit topology which consists of PV voltage adaptive balanced unit and cascaded high efficiency SEPIC fed buck-boost converter unit was proposed, in order to restrain the influence of the shadow effect of the serial-connected photovoltaic panel and the equivalent leakage current caused by the high frequency switching of the cascaded power converter. On the basis of that, a novel control strategy for the control unit was designed and optimized based on the Lyapunov switching function and extrimum seeking theory, which was namely coupled extrimum-seeking MPPT control with 2-Lyapunov switching, and thus the output power reduction caused by the shadow effect is minimized. |
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