Adaptive inertia matching method for deep sea ship hydrogen storage DC electric propulsion system

Abstract

The invention discloses an adaptive inertia matching method for a hydrogen storage DC electric propulsion system of a deep-sea ship, which adopts a single-bus DC power system structure, including a proton exchange membrane fuel cell power generation unit, an energy storage unit, a ship DC electric propulsion unit, and a constant power load Unit, resistive load unit, inertia adaptation unit 6 parts. The invention utilizes the energy storage characteristics of supercapacitors and the energy dynamic characteristics of large-scale voltage changes, and realizes adaptive matching of equivalent large-capacity capacitors on the DC bus side through the control of the duty cycle of the bidirectional Buck DC power converter in the inertia adaptation unit. In this way, the inertia characteristics of the system, the transient characteristics of the bus voltage and the steady-state voltage characteristics of the supercapacitor are improved, and the inertia adaptive matching of the ship's hydrogen storage electric propulsion system and the smooth switching of the ship's working conditions are realized. The invention has important engineering application prospects for the development of the application of hydrogen fuel cells in the field of electric propulsion ships and the stable power supply technology of new energy sources for ships.

Description

technical field [0001] The invention belongs to the field of ships and marine engineering and the field of new energy applications, and specifically relates to an adaptive inertia matching method for a hydrogen storage DC electric propulsion system of a deep-sea ship. Background technique [0002] With the increasingly serious impact of ship carbon emissions on the environment, the international demand for new energy ships is becoming more and more urgent. Hydrogen fuel cells have become the most popular choice for ships due to their high energy conversion efficiency, high energy density, zero carbon emissions, low vibration and noise, and long life. The best choice for electric propulsion. Hydrogen fuel cells have soft external characteristics and poor dynamic characteristics, so they need to be connected in parallel with energy storage devices. Energy storage batteries are used to balance the power fluctuations caused by load changes to form a hydrogen storage electric pro...

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Problems solved by technology

[0003] When the sea conditions are bad, the passive change of the working condition of the propeller of the ship reflects a typical random characteristic, and the capacity of the hydrogen storage power supply system is limited, which makes it difficult for the energy storage device to withstand the frequent changes of the high-proportion ship electric propulsion load condition. - The unequal power on the load side will inevitably cause changes in the output characteristics of the hydrogen fuel cell and low-frequency oscillations in the bus voltage. The problem of low-frequency stability on a large time scale is prominent, mainly because the space of the ship limits the capacity of the energy storage device, and it is difficult to quickly To send and absorb the unbalanced energy of the ship's electric propulsion system, it is necessary to consider how to achieve power balance when the working conditions of the high-proportion electric propulsion system change under the condition of limited-capacity energy storage devices

[0004] Therefore, in view of the limited space of deep-sea hydrogen storage DC electric propulsion ships and the serious influence of DC bus voltage caused by the random characteristics of electric propulsion loads under complex sea conditions, an effective adaptive inertia matching method is adopted to weaken the low-frequency oscillation of the system , Improving voltage stability is the key to ensuring the stable power supply of the ship's hydrogen storage DC power system

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