CN-121984067-A - Super-capacitor-assisted high-efficiency and rapid off-grid hydrogen production system and control method

CN121984067ACN 121984067 ACN121984067 ACN 121984067ACN-121984067-A

Abstract

The invention discloses a super-capacitor-assisted efficient and rapid off-grid hydrogen production system and a control method, and belongs to the technical field of new energy power generation control. The system comprises a wind turbine generator, a machine side converter, a grid side converter, a super capacitor bank, a multiphase multiple buck-boost converter, a boost converter and an electrolytic tank, wherein all parts are connected through a direct current bus, five working modes of off-grid hydrogen production, pure electric net hydrogen production, combined hydrogen production, partial power hydrogen production and direct grid connection are preset by a control method, the aim of maximizing economic benefits of the system is achieved, super capacitor dynamic model constraint is introduced, and an optimal working mode and a power distribution scheme are solved through an optimization algorithm. According to the invention, the super capacitor stabilizes power fluctuation, the multiphase multiple buck-boost converter is adaptive to a wide voltage range, and the five modes are adaptively switched and compatible and run off-grid, so that the problems of complex topology, low efficiency and slow response of the traditional hydrogen production system are solved, and the adaptability of the system to fluctuating wind power and the running economy are improved.

Inventors

SHEN YONGPENG
ZHAO CHEN
ZHANG QIUKUI
YANG XIAOLIANG
GUO LEILEI
ZHAO JIANGHAN
LI LINJIE
WANG SHIQIAN
GAO JINWU
ZHANG YIHAN
Zhang Yegui
YUAN XIAOFANG
ZHANG ZHENYA
LIU PU
CAO MINGHAO

Assignees

郑州轻工业大学

Dates

Publication Date: 20260505
Application Date: 20260109

Claims (8)

1. The high-efficiency rapid off-grid hydrogen production system assisted by the super capacitor is characterized by comprising a wind turbine generator, a machine side converter, a direct current bus, a grid side converter, a super capacitor bank, a multi-phase multi-step up-down converter, a boost converter and an electrolytic tank, wherein the output end of the wind turbine generator is connected with the input end of the machine side converter, the output end of the machine side converter is connected with the direct current bus, the direct current bus is respectively connected with the direct current end of the grid side converter, the two ends of the super capacitor bank and the input end of the multi-phase multi-step up-down converter, the alternating current end of the grid side converter is connected with a power grid through the boost converter, the output end of the multi-phase multi-step up-down converter is connected with the electrolytic tank, the machine side converter is a T-type three-level converter which continuously works in a rectification power generation mode except for a starting stage of the wind turbine generator, the multi-phase multi-step up-down converter is formed by connecting a plurality of bi-directional boost converters in parallel, the boost converter and the multi-phase multi-step up-down converter is in three working modes.
2. The super capacitor assisted high-efficiency rapid off-grid hydrogen production system of claim 1, wherein the three working modes of the grid-side converter are specifically: in the shutdown mode, all switching tubes are disconnected, and no energy flows between the boost converter and the grid-side converter; The grid-connected mode is operated in an inversion mode, the direct current of the direct current bus is inverted into 50Hz alternating current, and the alternating current is fed into a power grid through boosting; and in the rectification mode, the alternating current at the low-voltage side of the boost converter is rectified into direct current, and the direct current is stored in the super capacitor bank and is used for producing hydrogen through the electrolytic tank.
3. The supercapacitor-assisted high-efficiency fast off-grid hydrogen production system according to claim 1, wherein the three working modes of the multiphase multiple buck-boost converter are specifically: a shutdown mode, wherein all switch devices of the multiphase multiple buck-boost converter are disconnected, and no electric energy interaction exists between the electrolytic tank and the direct current bus; Buck mode: the switch-off is maintained and the switch-off is maintained, The closed state is maintained and the air is heated, And (3) with Complementary conduction device In the on state for a time of The off-state time is Period is t= + The conservation of inductive energy can be achieved: And (2) and By detecting current sensor The current flowing in the current transformer is dynamically adjusted according to the actual current and the target current The output current is controlled in a closed loop manner; Boost mode: the closed state is maintained and the air is heated, The switch-off is maintained and the switch-off is maintained, And (3) with Complementary conduction device At a closing time of The off-state time is Period is t= + The conservation of inductive energy can be achieved: ; can be simplified and obtained, ; And is also provided with By detecting current sensor The current flowing in the current transformer is dynamically adjusted according to the actual current and the target current And the output current is controlled in a closed loop mode.
4. The supercapacitor-assisted high-efficiency rapid off-grid hydrogen production system according to claim 3, wherein the multiphase multiple buck-boost converter is a three-phase triple bi-directional buck-boost converter, and the initial phases of the three phases differ from each other (N is the number of phases), the total output current is the sum of the output currents of the N bidirectional buck-boost converters, and the pulsation frequency is N times.
5. A supercapacitor-assisted efficient rapid off-grid hydrogen production control method suitable for the system of any one of claims 1 to 4, comprising the steps of: a) Collecting real-time input parameters, wherein the input parameters comprise wind power Internet electricity price Price of electricity Initial bus voltage ; B) Five working modes capable of being adaptively switched are preset, wherein the working modes comprise an off-grid hydrogen production mode, a pure-grid hydrogen production mode, a combined hydrogen production mode, a partial power hydrogen production mode and a direct grid-connected mode; c) Taking the maximization of the economic benefit of the system as an optimization target, introducing constraint conditions comprising a super capacitor dynamic model, and constructing a nonlinear optimization problem; d) Solving the nonlinear optimization problem by adopting an optimization algorithm to obtain an optimal working mode and power consumption of a power grid Grid-connected power generation Hydrogen production power ; E) And controlling the working states of the grid-side converter, the machine-side converter and the multiphase multiple buck-boost converter according to the solving result, and realizing real-time balance of wind power, grid interaction power and hydrogen production power.
6. The supercapacitor-assisted high-efficiency rapid off-grid hydrogen production control method according to claim 5, wherein the specific operation logic of the five working modes in the step b) is as follows: In the off-grid hydrogen production mode, a grid-side converter is stopped, and a machine-side converter rectifies and generates electricity; when the bus voltage is Greater than the voltage required by the cell to produce a particular current density When the multiphase multiple buck-boost converter works in the buck mode, the multiphase multiple buck-boost converter works in the buck mode When the device works in a boosting mode; the pure power grid hydrogen production mode comprises rectifying of a grid-side converter, shutdown of a machine-side converter, and multi-phase multiple buck-boost converter according to the following steps And The size is operated in a step-up or step-down mode; The combined hydrogen production mode is that a net side converter rectifies and a machine side converter rectifies and generates electricity; multi-phase multiple buck-boost converter And The size is operated in either a boost or buck mode, the wind power and the power grid are combined to supply power for the electrolytic tank; partial power hydrogen production mode includes inversion of grid-side converter, rectification and power generation of machine-side converter, and multiphase multiple step-up/step-down converter according to the requirement of the converter And The size is operated in either a boost or buck mode, part of wind power is used for producing hydrogen, and the other part is connected with the grid through a grid-side converter; And in a direct grid-connected mode, the grid-side converter inverts, the machine-side converter rectifies and generates electricity, the multiphase multiple buck-boost converter stops, and the wind power is fully grid-connected for generating electricity.
7. The supercapacitor-assisted high-efficiency rapid off-grid hydrogen production control method according to claim 5, wherein the system economic benefit R (τ) in step c) is calculated as follows: ; ; Wherein E H2 is the price of hydrogen in unit standard and is a constant; For hydrogen production efficiency, the unit is It is Is a function of (a) and (b), Is hydrogen production power; hydrogen production electrical energy for consumption from the grid; Is grid-connected power.
8. The method for controlling the hydrogen production by the super capacitor auxiliary high-efficiency and fast off-grid operation according to claim 5, wherein the optimization algorithm in the step d) is a secondary constraint programming algorithm or other nonlinear programming solving algorithm, and a wind power curve, an internet power price curve and a power consumption price curve of a preset time period [0, T ] are input during solving.

Description

Super-capacitor-assisted high-efficiency and rapid off-grid hydrogen production system and control method Technical Field The invention belongs to the technical field of new energy power generation control, and particularly relates to a super-capacitor-assisted efficient and rapid off-grid hydrogen production system and a control method. Background With the continuous improvement of the permeability of renewable energy sources such as wind power, the inherent intermittence and fluctuation of the renewable energy sources form a serious challenge for the efficient and stable operation of a new energy power system. The traditional grid-connected hydrogen production system is difficult to efficiently utilize wind power under off-grid conditions, and the alkaline electrolytic cell is slow in dynamic response, cannot effectively track power fluctuation, and restricts the large-scale development of green hydrogen energy. The off-grid hydrogen production system cannot acquire electric energy from the power grid to fill valleys when the power grid is low in electricity price, and cannot perform grid-connected power generation to cut peaks when the power grid is high in electricity price load, so that flexibility is insufficient. Meanwhile, the traditional new energy and off-grid hydrogen production system generally adopts a traditional AC-DC-AC topology, a special hydrogen production power supply (rectifying circuit) is connected to the output AC side to realize the control of the electrolytic cell, and a special energy storage system (AC-DC bidirectional converter and lithium ion battery) is matched to realize the instantaneous power balance of the system. The structure has the inherent defects of complex topology, high construction cost, multiple energy conversion times, low operation efficiency and the like. The prior similar technology comprises the invention patent of 'a new energy and off-grid hydrogen production system topological structure and a starting operation method thereof' (application number CN 202311533286.5) 'off-grid new energy hydrogen production starting control method, system, equipment and medium' (application number CN202511316196. X) 'a wind-light hydrogen production and storage integrated system operation planning method and system' (application number CN 202510442143.6). The technologies fail to solve the comprehensive technical problems of compatibility of grid connection and grid disconnection, rapid power regulation, low cost and high efficiency, so that a novel hydrogen production system structure which can be compatible with grid connection and grid disconnection operation and can realize rapid power regulation is needed to realize low construction cost, high efficiency and rapid hydrogen production control and power grid interaction. Disclosure of Invention The invention aims to provide a super-capacitor-assisted high-efficiency and quick off-grid hydrogen production system and a control method, which are used for solving the defects of complex topological structure, high cost, multiple energy conversion requirement, low efficiency and the like in the prior art. The technical scheme for solving the technical problems is as follows: The high-efficiency rapid off-grid hydrogen production system assisted by the super capacitor comprises a wind turbine generator, a machine side converter, a direct current bus, a grid side converter, a super capacitor bank, a multiphase multiple buck-boost converter, a boost converter and an electrolytic tank, wherein the output end of the wind turbine generator is connected with the input end of the machine side converter, the output end of the machine side converter is connected with the direct current bus, the direct current bus is respectively connected with the direct current end of the grid side converter, the two ends of the super capacitor bank and the input end of the multiphase multiple buck-boost converter, the alternating current end of the grid side converter is connected with a power grid through the boost converter, the output end of the multiphase multiple buck-boost converter is connected with the electrolytic tank, the machine side converter is a T-shaped three-level converter which continuously works in a rectifying power generation mode except for the starting stage of the wind turbine generator, the multiphase multiple buck-boost converter is formed by connecting a plurality of bidirectional buck-boost converters in parallel, the boost converter and the buck-boost converter is provided with three working modes, the buck-boost converter and the buck converter is a full-turn-on type MOSFET or the full-turn-on MOSFET. Further, the three working modes of the network side converter are specifically as follows: in the shutdown mode, all switching tubes are disconnected, and no energy flows between the boost converter and the grid-side converter; The grid-connected mode is operated in an inversion mode, the direct current of the direct curre