Proton exchange membrane fuel cell hybrid power supply system

Abstract

The invention discloses a proton exchange membrane fuel cell (PEMFC) hybrid power supply system, which comprises a power conversion unit including a PEMFC and an energy storage unit, and a control unit. The power conversion unit is a double-input Buck / Buck-Boost converter and adopts interleaved double-edge modulation in which the PEMFC serves as the main power supply of the hybrid power supply system and the energy storage unit serves as the backup power supply of the hybrid power supply system. The power conversion unit includes an input current single cycle controller and an output voltage PWM controller, wherein the input current single-cycle controller is used to control the input current of the PEMFC so that the average value of the input current follows the desired current, and the output voltage PWM controller is used to control the output voltage information of the power conversion unit so as to ensure the stability of the output voltage of the power conversion unit. The invention improves the dynamic response speed of the converter and simplifies the control closed loop design.

Description

technical field [0001] The invention belongs to the field of electric power conversion, and in particular relates to a proton exchange membrane fuel cell hybrid power supply system. Background technique [0002] Proton exchange membrane fuel cell (PEMFC) is a power generation device that directly converts the chemical energy of hydrogen into electrical energy. The products are water and heat, which is not limited by the Carnot cycle. It has the characteristics of high efficiency, low temperature start-up, and no pollution. It is considered to be one of the new high-efficiency, energy-saving and environmentally friendly power generation technologies in the 21st century. Because the PEMFC independent power supply system is greatly affected by the working environment and load changes, the output characteristics are soft, and it cannot be started with load. Therefore, the PEMFC hybrid power supply system composed of PEMFC and battery or super capacitor has gradually attracted pe...

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Problems solved by technology

[0005] Compared with the prior art, the present invention has the remarkable advantages as follows: 1) The present invention replaces multiple single-input DC converters with a multi-input DC converter and shares a set of filter inductors and filter capacitors, which can reduce components and simplify the circuit structure , reduce system cost; 2) the dual-input Buck / Buck-Boost converter of the present invention adopts interleaved double-edge modulation, which reduces the ripple of the inductor current and improves the dynamic response and efficiency of the converter; 3) the present invention compares the load The required power and the maximum power provided by the PEMFC determine the working mode of the power conversion unit, which can effectively coordinate multiple input sources; 4) The present invention uses a control technology combining traditional linear carrier modulation technology and nonlinear single-cycle control technology to effectively solve the power problem. When there are multiple working modes in the conversion unit, the design of the closed-loop system is complex and there is a problem of coupling between them

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