Fuel cell generator

Abstract

The invention discloses a fuel cell generator, comprising a main circuit and a control system. The main circuit comprises a fuel cell, a filter, a DC-DC converter (DC-DC converter), a three-phase four-wire inverter, a static switch, a bidirectional DC-DC converter, a super-capacitor bank and a control system, and the control system comprises two pulsating voltage control elements, two inner circuit control elements, a direct current output side current detection element and a super-capacitor voltage control element. The generator provides a high-frequency component in a power generating systemoutput power by the bidirectional DC-DC converter and the super-capacitor bank, and simultaneously controls the voltages from direct current positive and negative buses to a midpoint. When the powernetwork is asymmetric or the power generating system three-phase output power is imbalance, the generator efficiently stabilizes the low-frequency voltage pulsation generated from the direct current positive and negative buses to the midpoint, and replaces the large-capacitance electrolytic capacitor on the direct current bus of the prior fuel cell generator, thus the reliability and the service life of the system can not be restricted by the reliability and the service life of the electrolytic capacitor, and the reliability and the service life of the generator are improved.

Description

technical field [0001] The invention relates to a fuel cell power generation device, especially a fuel cell power generation device without an electrolytic capacitor. Background technique [0002] The fuel cell is restricted by its own internal mechanical characteristics, its dynamic response is slow, it is difficult to meet the demand when the load changes suddenly, and the load change may also cause the fuel cell to work beyond the normal range, affecting its service life. In the current fuel cell power generation device Supercapacitors and bidirectional DC-DC converters are mostly used as auxiliary energy storage links, which are directly or indirectly connected in parallel to the output of fuel cells, and only play an energy buffer role for fuel cells during load disturbances or cold starts. Although auxiliary energy storage The link is essential in the fuel cell power generation device, but its role is relatively simple. The inverter of a large-capacity fuel cell power...

AI Technical Summary

Problems solved by technology

[0002] The fuel cell is restricted by its own internal mechanical characteristics, its dynamic response is slow, it is difficult to meet the demand when the load changes suddenly, and the load change may also cause the fuel cell to work beyond the normal range, affecting its service life. In the current fuel cell power generation device Supercapacitors and bidirectional DC-DC converters are mostly used as auxiliary energy storage links, which are directly or indirectly connected in parallel to the output of fuel cells, and only play an energy buffer role for fuel cells during load disturbances or cold starts. Although auxiliary energy storage The link is essential in the fuel cell power generation device, but its role is relatively simple

The inverter of a large-capacity fuel cell power generation device adopts a three-phase four-wire structure, which can meet the requirements of grid connection and independent operation. However, when the power grid is asymmetrical or the three-phase output power of the power generation system is unbalanced, there will be a Low-frequency voltage pulsation, the traditional fuel cell power generation device adopts the method of connecting large-capacity electrolytic capacitors in parallel between the positive and negative DC bus bars and the midpoint to filter out low-frequency voltage pulsation, but the use of electrolytic capacitors will inevitably bring about life and reliability of the device etc.

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