A wind-solar residual power index-based switching sequencing method

Abstract

The present application relates to the technical field of wind, light and water hydrogen production scheduling, and particularly relates to a switching sequence method based on wind and light surplus power index, comprising: dividing the surplus power slope grade through the change direction, change amplitude and continuous state of wind power surplus and photovoltaic surplus power, and combining the consumable power interval to generate the wind and light surplus power index, so that the switching is expanded from single surplus power to the comprehensive judgment of surplus power change speed and acceptance boundary; dividing the electrolytic cell climbing ability grade through the current response state, temperature recovery state and hydrogen production fluctuation state to form the ability grade sequence corresponding to the dynamic bearing capacity of the electrolytic cell; then, the electrolytic cell with the corresponding climbing ability grade is matched according to the surplus power slope grade, so that the impact of sudden rising and sudden falling surplus power on the low response electrolytic cell can be reduced; further, the continuous operation state and the latest switching state are combined to correct the sequence position, so that the short-time repeated switching is reduced; the wind and light surplus power consumption stability and hydrogen production process stability are improved.

Description

Technical Field

[0001] This invention relates to the technical field of wind, solar and hydropower hydrogen production scheduling, and in particular to a scheduling method based on wind and solar surplus power index. Background Technology

[0002] In off-grid or weakly grid-connected electrolytic water production hydrogen stations with wind-solar-hydro complementary systems, wind power branches, photovoltaic branches, and hydropower compensation branches jointly supply power to the hydrogen production rectifier bus. Multiple electrolyzers are connected in parallel to the hydrogen production load side, and the surplus power from wind power and photovoltaic power is received through switching sequence. Since the surplus power from wind power is affected by wind speed fluctuations, and the surplus power from photovoltaic power is affected by irradiance changes and cloud cover, the two may have opposite power directions, different amplitudes of change, and inconsistent durations at the same time. If the switching is carried out only according to the total surplus power, the order of electrolyzer number, or the ratio of rated capacity, it is easy for electrolyzers with weak climbing ability to receive rapidly rising or falling surplus power, which will lead to current overshoot, delayed recovery of cell temperature, fluctuations in hydrogen production flow, and repeated switching in a short period of time, making it difficult to balance the surplus power consumption efficiency and the operational stability of the electrolyzers.

[0003] For example, CN111463826A discloses a method and system for configuring and optimizing the control of alkaline electrolyzer arrays for wind power hydrogen production. This method determines the configuration capacity of the electrolyzer array based on the spatiotemporal dispersion characteristics of peak wind power and the overload characteristics of the electrolyzers. It also divides the operating states of individual electrolyzers into rated power operation, fluctuating power operation, overload power operation, and shutdown states, and then assigns rotating duties to individual electrolyzers based on the real-time output power of the wind turbines. While this scheme can improve the power configuration problem of electrolyzer arrays in wind power hydrogen production scenarios, its control objects are mainly wind power and the operating state of the electrolyzers. It does not further break down the total surplus power sequence formed by wind power surplus and photovoltaic surplus power at the same sampling time into continuously changing segments, nor does it classify the surplus power slope level based on the direction, amplitude, and duration of surplus power changes. Therefore, in hydrogen production stations where wind and solar surplus power are jointly connected and the surplus power change rate frequently switches, there is still a mismatch between the switching sequence and the dynamic ramp-up capability of the electrolyzers.

[0004] For example, CN111826669A discloses a large-scale water electrolysis hydrogen production system and control method with wide power fluctuation adaptability. It uses multiple parallel water electrolysis hydrogen production modules, a system power shunt controller, and a module power shunt controller to enable water electrolysis hydrogen production modules of different power levels to adapt to wide power fluctuation input. The key point of this scheme is the power shunt structure and wide power fluctuation tolerance of the large-scale hydrogen production system, which can improve the system's adaptability to variable power input. However, this scheme does not classify the ramp-up capability level of the electrolyzer based on the current response state, temperature recovery state, and hydrogen production fluctuation state of the electrolyzer, nor does it correct the sorting position based on the continuous operation state and the most recent switching state after forming the candidate switching queue. Therefore, in the long-term operation of multiple electrolyzers, it is still difficult to suppress short start-stop phenomena such as being put into operation and then cut off, and being put into operation and then cut off again.

[0005] In summary, given the existing wind-solar hydrogen production switching control technologies suffer from problems such as an overemphasis on power capacity matching, a lack of residual power slope level identification, failure to incorporate the dynamic response capability of electrolyzers into the switching sequence, and difficulty in suppressing short start-stop cycles, this invention proposes a switching sequence method based on wind and solar residual power indexes. This method forms a total residual power sequence by combining wind and solar residual power, classifies residual power slope levels according to continuous change segments, and generates a wind and solar residual power index by combining the absorbable power range. Furthermore, it forms an electrolyzer capacity level sequence based on current response status, temperature recovery status, and hydrogen production fluctuation status, matches electrolyzers with corresponding ramp-up capability levels according to residual power slope levels, and corrects the candidate switching queue by combining continuous operation status and recent switching status. Therefore, the problem this invention aims to solve is how to match the switching sequence of multiple electrolyzers with the residual power change rate and electrolyzer ramp-up capability under conditions of rapid fluctuations in wind and solar residual power. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this section, the abstract and title of the invention. Such simplifications or omissions shall not be used to limit the scope of the present invention.

[0007] In view of the aforementioned existing problems, the present invention is proposed.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for sorting and switching power consumption based on wind and solar surplus power index includes: classifying surplus power slope levels according to the power change direction, change magnitude and duration of wind and solar surplus power, and generating wind and solar surplus power index in combination with the power absorption range; Based on the current response state, temperature recovery state, and hydrogen production fluctuation state of the electrolyzer, the electrolyzer ramp-up capability level is classified, and the electrolyzer capability level sequence is obtained by arranging the electrolyzer ramp-up capability levels. Based on the residual power slope level in the wind and solar residual power index, the electrolyzers with the corresponding ramping ability level in the electrolyzer capacity level sequence are included in the candidate switching queue. Based on the continuous operating status and most recent switching status of each electrolytic cell in the candidate switching queue, the sorting position of the candidate switching queue is corrected to obtain the electrolytic cell switching sorting result.

[0009] The beneficial effects of this invention are as follows: This invention classifies surplus power slope levels by varying the direction, magnitude, and duration of changes in surplus wind and solar power, and generates a surplus power index based on the absorbable power range. This expands the switching criteria from a single surplus power level to a comprehensive judgment based on the rate of change of surplus power and the acceptance boundary. Furthermore, it classifies the electrolyzer's ramp-up capability levels by considering current response, temperature recovery, and hydrogen production fluctuations, forming a capability level sequence corresponding to the electrolyzer's dynamic carrying capacity. Matching electrolyzers with corresponding ramp-up capability levels according to the surplus power slope level reduces the impact of rapid increases and decreases in surplus power on low-response electrolyzers. Additionally, it combines continuous operation status and recent switching status to correct the sorting position, reducing repeated switching in short periods. Therefore, this invention improves the stability of surplus wind and solar power absorption, the continuity of electrolyzer operation, and the stability of the hydrogen production process. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart illustrating the power allocation and sorting method based on wind and solar surplus power index as shown in this invention. Detailed Implementation

[0011] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0012] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort should fall within the scope of protection of this invention.

[0013] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0014] In a preferred embodiment, the present invention is applied to a multi-electrolyzer switching sequence in a wind-solar-hydropower hybrid off-grid or weakly grid-connected water electrolysis hydrogen production station. The off-grid or weakly grid-connected water electrolysis hydrogen production station includes a wind turbine, a photovoltaic array, a hydropower regulation unit, a DC bus, a hydrogen production converter, multiple alkaline electrolyzers or proton exchange membrane electrolyzers, a hydrogen production station energy management system, and an electrolyzer group control unit. The hydrogen production station energy management system receives wind power output, photovoltaic power output, hydropower regulation power, station base load, electrolyzer operating power, electrolyzer current, cell temperature, cooling outlet temperature, hydrogen production flow rate, and hydrogen production pressure at the same sampling time. The electrolyzer group control unit arranges the order of activation and deactivation of multiple electrolyzers according to the wind and solar surplus power index, electrolyzer capacity level sequence, and candidate activation / deactivation queue, thereby reducing the impact of rapid fluctuations in wind and solar surplus power on electrolyzer current, cell temperature, and hydrogen production pressure.

[0015] According to an embodiment of the present invention, in combination Figure 1 The flowchart shown illustrates a method for scheduling and splitting power based on wind and solar surplus power indexes, which specifically includes the following steps: S1. Based on the direction, magnitude, and duration of power changes in wind power surplus electricity and photovoltaic surplus electricity, classify the surplus electricity slope levels and generate a wind and solar surplus electricity index by combining the absorbable power range. Note that the following should be noted in this step: S1.1. Add the wind power surplus power sequence and the photovoltaic surplus power sequence at the same sampling time to obtain the total surplus power sequence.

[0016] In this embodiment, the wind power surplus power sequence is the remaining power sequence after subtracting the allocated power consumption and the restricted power from the wind power side from the active power output of the wind turbine at the grid connection point or DC combiner point; the photovoltaic surplus power sequence is the remaining power sequence after subtracting the allocated power consumption and the restricted power from the photovoltaic side from the active power output of the photovoltaic array at the inverter side or DC combiner side; both the wind power surplus power sequence and the photovoltaic surplus power sequence use the same sampling time marker, and the sampling period is 5s; under weak grid-connected operation, if there is a backfeed power limit constrained by the grid dispatch within the station, the wind power and photovoltaic power exceeding the backfeed power limit and not yet absorbed by the station's base load are used as the source of surplus power; under off-grid operation, the wind power and photovoltaic power exceeding the station's base load, hydropower regulation absorption power, and the power of the operating electrolyzer are used as the source of surplus power.

[0017] Before entering step S1.1, the wind power surplus power sequence and the photovoltaic surplus power sequence are aligned based on the sampling time. When the wind power surplus power sequence or the photovoltaic surplus power sequence is missing a power value at a certain sampling time, the effective power value of the adjacent previous sampling time is used to make up for it. When the power value is missing for three consecutive sampling periods, the time period is removed from the continuous change segment division process, and the sampling times on both sides of the removed time period are used as the segment boundaries.

[0018] Furthermore, at each sampling time, the residual power value of wind power and the residual power value of photovoltaic power at that sampling time are added together, and the sum is taken as the total residual power value at that sampling time. The total residual power values ​​from multiple sampling times are arranged in chronological order to form a total residual power sequence; for example, with a sampling period of 5 seconds, at 10:00:00, 10:00:05, 10:00:10, 10:00:15, 10:00:20, 1... At the sampling time of 0:00:25, the surplus power sequence of wind power is 620kW, 650kW, 690kW, 735kW, 780kW, and 820kW, and the surplus power sequence of photovoltaic power is 280kW, 295kW, 310kW, 330kW, 350kW, and 365kW, respectively. Therefore, the total surplus power sequence is 900kW, 945kW, 1000kW, 1065kW, 1130kW, and 1185kW, respectively.

[0019] Preferably, the above processing enables wind power surplus and photovoltaic surplus to form a unified dispatchable power object under the same time base, avoiding inconsistencies in electrolytic cell switching commands caused by separate judgments by the wind power side and the photovoltaic side.

[0020] S1.2. Subtract the power values ​​at adjacent sampling times from the total residual power sequence to obtain the adjacent power difference sequence, and determine the direction of residual power change according to the positive and negative states of the adjacent power difference sequence. Wherein: When the adjacent power difference in the adjacent power difference sequence is positive, the direction of residual charge change between adjacent sampling times corresponding to the adjacent power difference is determined as the upward direction. When the adjacent power difference in the adjacent power difference sequence is negative, the direction of the residual charge change between adjacent sampling times corresponding to the adjacent power difference is determined as the downward direction. When the adjacent power difference in the adjacent power difference sequence is zero, the direction of residual charge change between adjacent sampling times corresponding to the adjacent power difference is determined as the stationary direction.

[0021] S1.3. Sample times with consistent residual power change direction are grouped into continuous change segments, and the residual power change amplitude and residual power duration are determined based on the power value at the beginning and end of the continuous change segment and the segment length.

[0022] In this embodiment, "continuous consistency" means that the direction of residual power change is the same between adjacent sampling times, and the number of consecutive occurrences of the same residual power change direction reaches more than 2. When the same residual power change direction occurs only once, and the amplitude of the adjacent power difference is less than 15kW, the adjacent power difference is merged into the adjacent stable direction segment. When the same residual power change direction occurs only once, and the amplitude of the adjacent power difference reaches 15kW, the two sampling times where the adjacent power difference is located are treated as separate short segments.

[0023] Specifically, first, the direction of residual power change between every two adjacent sampling times is obtained according to step S1.2. Then, starting from the earlier side, the current direction of residual power change is compared with the next direction of residual power change. If they are consistent, the corresponding sampling times are continued to be included in the same continuous change segment. If they are inconsistent, the current adjacent sampling time is taken as the end sampling time of the current continuous change segment, and the next adjacent sampling time is taken as the start sampling time of the next continuous change segment. For the stationary direction, if the amplitude of the difference between three consecutive adjacent power values ​​is no greater than 10kW, the corresponding sampling times are merged into a stationary continuous change segment. If the stationary direction is sandwiched between an upward or downward segment, and the duration of the stationary direction does not exceed 10s, it is merged according to the side with the longer duration of the segment between the preceding and following segments to reduce segment breaks caused by measurement noise.

[0024] Furthermore, the total residual power value at the first sampling time of the continuously changing segment is taken as the first-end power value, and the total residual power value at the last sampling time of the continuously changing segment is taken as the last-end power value. The difference between the last-end power value and the first-end power value is taken as the first-end power difference of the segment. The difference between the maximum and minimum total residual power values ​​within the continuously changing segment is taken as the maximum power difference of the segment. The average value of the power differences between adjacent sampling times within the continuously changing segment is taken as the average power difference of the segment.

[0025] For example, if the sampling time for a continuously changing segment is from 10:00:00 to 10:00:25, the sampling period is 5s, and the total residual power values ​​are 900kW, 945kW, 1000kW, 1065kW, 1130kW, and 1185kW respectively, then the power value at the beginning is 900kW, the power value at the end is 1185kW, the power difference between the beginning and end of the segment is 285kW, the maximum power difference of the segment is 285kW, the average power difference of the segment is 57kW, the segment duration is 25s, and the number of consecutive changes in the same direction is 5.

[0026] As an example, the residual power variation includes the power difference between the beginning and end of a segment, the maximum power difference of a segment, and the average power difference of a segment; wherein, the power difference between the beginning and end of a segment is the difference between the power value at the end of a continuously changing segment and the power value at the beginning; the maximum power difference of a segment is the difference between the maximum power value and the minimum power value within a continuously changing segment; and the average power difference of a segment is the average of the power differences between adjacent sampling times within a continuously changing segment.

[0027] As an example, the residual charge duration includes the segment duration and the number of consecutive changes in the same direction; wherein, the segment duration is the time length between the first sampling time and the last sampling time within the continuous change segment; the number of consecutive changes in the same direction is the number of adjacent sampling times within the continuous change segment where the residual charge change direction is continuously consistent.

[0028] S1.4. Based on the ratio of the amplitude of residual charge change to the duration of residual charge, classify the residual charge slope level of continuously changing segments. Specifically, this includes: The slope value of a segment is obtained by the ratio of the power difference between the beginning and end of a continuously changing segment to the duration of the segment. When the slope value of a segment is within the boundary of a stationary slope, the continuously changing segments are classified into stationary residual slope levels. When the slope value of a segment is positive, and the slope value of a segment exceeds the steady slope boundary and reaches the steep slope boundary, the continuously changing segment is classified into the steep residual power slope level. When the slope value of a segment is positive, and the slope value of the segment exceeds the steady slope boundary but does not reach the steep slope boundary, the continuously changing segment is classified into the slow-rising residual power slope level. When the slope value of a segment is negative, and the magnitude of the descending slope determined by the segment slope value reaches the boundary of the steep descent slope, the continuously changing segments are classified into the steep descent residual power slope level. When the slope value of a segment is negative, and the slope value of the segment exceeds the steady slope boundary and the magnitude of the descending slope determined by the slope value of the segment does not reach the steep descent slope boundary, the continuously changing segments are classified into the slow descent residual power slope level. When the slope value of a segment is negative, the magnitude of the slope value is used as the magnitude of the falling slope.

[0029] In a preferred embodiment, the steady slope boundary is set at no less than -1 kW / s and no more than 1 kW / s, the steep slope boundary is set at no less than 8 kW / s, and the steep slope boundary is set at no less than 8 kW / s. The steady slope boundary is determined based on the power metering error of the hydrogen production station, the minimum adjustment resolution of the electrolyzer group control unit, and the residual power fluctuation noise under a 5-second sampling period. In this embodiment, the power metering error of the hydrogen production station is 0.5%, the minimum power adjustment resolution of the electrolyzer group control unit is 5 kW, and the power fluctuation amplitude without scheduling significance within three consecutive sampling periods is less than 15 kW. Therefore, the steady slope boundary is determined to be ±1 kW / s. The steep slope boundary is determined based on the high climbing ability level of the electrolyzer group control unit. The acceptable start-up rate of the electrolyzer and the allowable power increase rate of the hydrogen production converter unit are obtained. In this embodiment, the typical adjustment time for a single 1000kW electrolyzer to increase from 300kW to 800kW is 60s, corresponding to a power increase rate of approximately 8.3kW / s. Therefore, the steep increase slope boundary is determined to be 8kW / s. The steep decrease slope boundary is obtained according to the safe decompression rate of the electrolyzer, the allowable decrease in hydrogen production pressure, and the allowable power decrease rate of the converter unit. In this embodiment, the typical adjustment time for a single 1000kW electrolyzer to decrease from 800kW to 300kW is 60s, corresponding to a power decrease rate of approximately 8.3kW / s. Therefore, the steep decrease slope boundary is determined to be 8kW / s.

[0030] It should be noted that the above boundaries can be revised based on the rated power of the electrolyzer, the minimum stable operating power, the load regulation rate given by the manufacturer, and the on-site commissioning data of the hydrogen production station, but the same set of boundaries shall be used for the same hydrogen production station in the same operating shift.

[0031] Preferably, if the slope value of a segment is between -1kW / s and 1kW / s, the continuously changing segment is classified as a stable residual power slope level; if the slope value of a segment is greater than 1kW / s and less than 8kW / s, the continuously changing segment is classified as a gradually increasing residual power slope level; if the slope value of a segment is not less than 8kW / s, the continuously changing segment is classified as a rapidly increasing residual power slope level; if the slope value of a segment is less than -1kW / s and the amplitude of the slope value is less than 8kW / s, the continuously changing segment is classified as a gradually decreasing residual power slope level; if the slope value of a segment is negative and the amplitude of the slope value is not less than 8kW / s, the continuously changing segment is classified as a rapidly decreasing residual power slope level.

[0032] S1.5. Based on the end power value of the continuously changing segment and the minimum stable operating power of the electrolytic cell, the power absorption range is defined, and the correspondence between the residual power slope level and the power absorption range is established to obtain the wind and solar residual power index.

[0033] Specifically, the minimum stable operating power of the electrolyzer is the lowest power allowed for continuous operation within the rated temperature range, rated current range, and rated hydrogen production pressure range. In this embodiment, the hydrogen production station is equipped with six 1000kW electrolyzers, with a minimum stable operating power of 300kW per electrolyzer. The lower limit of the absorbable power range is the minimum stable operating power of a single electrolyzer. When the power value at the end of a continuously changing segment is less than the minimum stable operating power of a single electrolyzer, the absorbable power range is recorded as 0kW to the end power value. In this case, no new electrolyzers are added, and only the existing electrolyzers are allowed to reduce their load to absorb excess power. When the power value at the end of a continuously changing segment is less than the minimum stable operating power of a single electrolyzer, the absorbable power range is recorded as 0kW to the end power value. At this time, no new electrolyzers are added, and only the existing electrolyzers are allowed to reduce their load to absorb excess power. When the power is less than the minimum stable operating power of a single electrolytic cell, the lower limit of the absorbable power range is set at 300kW, and the upper limit of the absorbable power range is set at the smaller value between the end power value of the continuously changing segment and the adjustable power margin of the currently operating electrolytic cell. If the end power value of the continuously changing segment is 1185kW and the adjustable power margin of the currently operating electrolytic cell is 500kW, then the absorbable power range is 300kW to 500kW. If the end power value of the continuously changing segment is 1185kW and the adjustable power margin of the currently operating electrolytic cell is 1600kW, then the absorbable power range is 300kW to 1185kW.

[0034] Preferably, for the cut-off and sorting scenario, the absorbable power range corresponds to the power range that needs to be released from the electrolytic cell group. Its lower limit is taken as the minimum stable operating power of a single electrolytic cell of 300kW, and its upper limit is taken as the operating power of the electrolytic cells that cannot be supported by the surplus power of wind and solar power after the surplus power decreases.

[0035] Furthermore, the corresponding relationships include the starting sampling time, ending sampling time, initial power value, final power value, residual power change direction, power difference between the beginning and end of the segment, segment duration, number of consecutive changes in the same direction, residual power slope level, lower limit of the absorbable power range, upper limit of the absorbable power range, and switching direction for the continuously changing segment. Among these, the switching direction is determined based on the residual power change direction. When the residual power change direction is upward, the switching direction is "input"; when the residual power change direction is downward, the switching direction is "output"; when the residual power change direction is stable, the switching direction is determined based on the difference between the final power value and the current operating power of the electrolytic cell group. A positive difference corresponds to input, a negative difference corresponds to output, and a difference within ±50kW does not form a switching direction.

[0036] For example, a wind and solar surplus power index can be recorded as follows: the continuous change segment is from 10:00:00 to 10:00:25, the power value at the beginning is 900kW, the power value at the end is 1185kW, the surplus power change direction is upward, the power difference between the beginning and end of the segment is 285kW, the segment duration is 25s, the number of consecutive changes in the same direction is 5, the surplus power slope level is the rapid rise surplus power slope level, the absorbable power range is from 300kW to 1185kW, and the switching direction is input.

[0037] It should be noted that this step forms a unified total surplus power sequence by combining wind power surplus power and photovoltaic surplus power at the same sampling time. Based on the direction, magnitude, and duration of surplus power changes, the randomly fluctuating wind and solar surplus power is converted into a wind and solar surplus power index that can be processed by the electrolyzer group control unit. This solves the problems of dispersed sources of wind power surplus power and photovoltaic surplus power fluctuations, difficulty in distinguishing the speed of change, and unclear power switching range in off-grid or weakly grid-connected hydrogen production stations. This allows the selection of subsequent candidate electrolyzers to be constrained by both the surplus power slope level and the absorbable power range, reducing frequent electrolyzer switching and power mismatch caused by sudden increases or decreases in surplus power.

[0038] S2. Based on the current response state, temperature recovery state, and hydrogen production fluctuation state of the electrolyzer, classify the electrolyzer ramp-up capability levels and arrange them into an electrolyzer capability level sequence. Note that the following should be noted in this step: S2.1. Based on the electrolytic cell number, determine the current arrival time, current overshoot amplitude, and current stabilization time from the current regulation curve during the load regulation process to obtain the current response state.

[0039] In this embodiment, the load adjustment process is the process by which an electrolyzer group control unit sends a power increase or decrease command to a single electrolyzer, and the electrolyzer then transitions from one stable operating power to another. Taking a 1000kW alkaline electrolyzer as an example, two typical load adjustment processes—from 400kW to 800kW and from 800kW to 400kW—are selected as the data source for classifying the electrolyzer's ramp-up capability levels. The current adjustment curve is obtained by the electrolyzer's DC-side current sensor with a 1s sampling period. The tank temperature is obtained by the tank outlet temperature sensor and the tank middle temperature sensor. The cooling outlet temperature difference is obtained by the difference between the coolant outlet temperature and the coolant inlet temperature. The hydrogen production flow rate is obtained by the hydrogen outlet mass flow meter. The hydrogen production pressure is obtained by the hydrogen outlet pressure sensor.

[0040] The above parameters were selected from data 60s before load adjustment, during load adjustment, and 180s after load adjustment, because this time range can cover the three processes of current change, thermal inertia recovery, and hydrogen production pressure stabilization.

[0041] Specifically, the current regulation curves of each electrolytic cell are grouped according to the cell number. The moment the load regulation command is issued is taken as the current response start point. The time between the moment when the current value first enters the range of ±2% of the target current value and the current response start point is taken as the current arrival time. The ratio of the difference between the current peak value exceeding the target current value and the target current value during the load regulation process to the target current value is taken as the current overshoot amplitude. The time between the moment when the current value enters the range of ±2% of the target current value and does not leave the range for 30 seconds and the current response start point is taken as the current stabilization time. The current response status includes the electrolytic cell number, current response start point, target current value, current arrival time, current overshoot amplitude, and current stabilization time.

[0042] For example, when the electrolytic cell numbered E03 is increased from 400kW to 800kW, the target current value is 4000A. The current response starts at 10:05:00. The current value first enters the range of 3920A to 4080A at 10:05:22, with a peak current value of 4180A. The current value remains in the range of 3920A to 4080A for 30 consecutive seconds starting from 10:05:38. Therefore, the current arrival time for cell numbered E03 is 22 seconds, the current overshoot is 4.5%, and the current stabilization time is 38 seconds.

[0043] S2.2. Based on the temperature change of the tank before and after the load adjustment process, the temperature difference at the cooling outlet, and the temperature drop time, the temperature recovery state is obtained.

[0044] Specifically, the average tank temperature within 60 seconds before the load adjustment command is issued is taken as the tank temperature before adjustment; the difference between the highest tank temperature within 180 seconds after the load adjustment is completed and the tank temperature before adjustment is taken as the tank temperature change; the maximum difference between the coolant outlet temperature and the coolant inlet temperature within 180 seconds after the load adjustment is completed is taken as the cooling outlet temperature difference; and the time between the moment when the tank temperature drops from the highest temperature to within 3°C above the tank temperature before adjustment and the moment when the tank reaches the highest temperature is taken as the temperature drop time.

[0045] The temperature recovery status includes the electrolytic cell number, the cell temperature before adjustment, the highest temperature of the cell, the temperature change of the cell, the temperature difference at the cooling outlet, and the temperature drop time. For example, the cell temperature before adjustment of cell number E03 is 72℃, the highest temperature of the cell after load adjustment is 77℃, the maximum temperature difference at the cooling outlet is 6℃, and the cell temperature drops to below 75℃ after 110s. Therefore, the temperature change of cell number E03 is 5℃, the temperature difference at the cooling outlet is 6℃, and the temperature drop time is 110s.

[0046] S2.3. Based on the hydrogen production flow deviation, hydrogen production pressure fluctuation, and hydrogen production flow stabilization time before and after the load adjustment process, the hydrogen production fluctuation state is obtained.

[0047] Specifically, the average hydrogen production flow rate within 60 seconds before the load adjustment command is issued is taken as the pre-adjustment hydrogen production flow rate; the maximum deviation between the hydrogen production flow rate and the target hydrogen production flow rate within 180 seconds after the load adjustment is completed is taken as the hydrogen production flow rate offset; the difference between the highest and lowest hydrogen production pressure within 180 seconds after the load adjustment is completed is taken as the hydrogen production pressure fluctuation; and the time between the start of the hydrogen production flow rate entering the ±3% range of the target hydrogen production flow rate and not leaving the range for 60 seconds and the time when the load adjustment command is issued is taken as the hydrogen production flow rate stabilization time.

[0048] The hydrogen production fluctuation status includes the electrolyzer number, the hydrogen production flow rate before adjustment, the target hydrogen production flow rate, the hydrogen production flow rate deviation, the hydrogen production pressure fluctuation, and the hydrogen production flow rate stabilization time; for example, the target hydrogen production flow rate for cell E03 is 160 Nm³. 3 / h, the maximum deviation of hydrogen production flow rate within 180s after load adjustment is 8Nm 3 The hydrogen production pressure was highest at 1.64 MPa and lowest at 1.56 MPa per hour. The hydrogen production flow rate remained at 155.2 Nm³ for 60 seconds after 96 seconds. 3 / h to 164.8Nm 3 If the hydrogen production flow rate is within the range of / h, then the hydrogen production flow rate deviation for E03 is 5%, the hydrogen production pressure fluctuation is 0.08MPa, and the hydrogen production flow rate stabilization time is 96s.

[0049] S2.4. Compare the current response state, temperature recovery state, and hydrogen production fluctuation state with the rated operating boundary of the electrolyzer to obtain the current response level, temperature recovery level, and hydrogen production fluctuation level. Specifically, this includes: When the current arrival time, current overshoot amplitude, and current stagnation time in the current response state are all within the current response boundary, the current response state is classified as a high current response level. When at least one of the current arrival time, current overshoot amplitude, and current stagnation time in the current response state exceeds the current response boundary, the current response state is classified as a low current response level. When the temperature change of the tank, the temperature difference of the cooling outlet, and the temperature drop time in the temperature recovery state are all within the temperature recovery boundary, the temperature recovery state is classified as a high temperature recovery level. When at least one of the following in the temperature recovery state—the tank temperature change, the cooling outlet temperature difference, and the temperature drop time—exceeds the temperature recovery boundary, the temperature recovery state is classified as a low temperature recovery level. When the hydrogen production flow rate deviation, hydrogen production pressure fluctuation, and hydrogen production flow rate stabilization time in the hydrogen production fluctuation state are all within the hydrogen production fluctuation boundary, the hydrogen production fluctuation state is classified as a low hydrogen production fluctuation level. When at least one of the following—hydrogen production flow deviation, hydrogen production pressure fluctuation, and hydrogen production flow stabilization time—exceeds the hydrogen production fluctuation boundary, the hydrogen production fluctuation state is classified as a high hydrogen production fluctuation level.

[0050] Specifically, the rated operating boundaries of the electrolyzer include current response boundaries, temperature recovery boundaries, hydrogen production fluctuation boundaries, rated current boundaries, rated tank temperature boundaries, rated cooling outlet temperature difference boundaries, rated hydrogen production flow rate boundaries, and rated hydrogen production pressure boundaries. Among them, the current response boundaries include current arrival time not exceeding 30s, current overshoot not exceeding 5%, and current stabilization time not exceeding 60s; the temperature recovery boundaries include tank temperature change not exceeding 6℃, cooling outlet temperature difference not exceeding 8℃, and temperature drop time not exceeding 180s; the hydrogen production fluctuation boundaries include hydrogen production flow rate deviation not exceeding 6%, hydrogen production pressure fluctuation not exceeding 0.10MPa, and hydrogen production flow rate stabilization time not exceeding 120s; the rated current boundary is the target current value ±2%, the rated tank temperature boundary is 60℃ to 85℃, the rated cooling outlet temperature difference boundary is 0℃ to 8℃, the rated hydrogen production flow rate boundary is the target hydrogen production flow rate ±3%, and the rated hydrogen production pressure boundary is 1.50MPa to 1.70MPa.

[0051] In this embodiment, the current response boundary, temperature recovery boundary, and hydrogen production fluctuation boundary are obtained jointly from the electrolyzer manufacturer's technical manual, the hydrogen production station commissioning report, and continuous operation data. Specifically, the rated current change time, allowable overshoot range, allowable tank temperature range, cooling system design temperature difference, and allowable hydrogen production pressure range given in the manufacturer's technical manual are used as initial boundaries. Then, during the commissioning phase of the hydrogen production station, each electrolyzer undergoes at least five load adjustment tests from 400kW to 800kW and at least five load adjustments from 800kW to 400kW. Finally, the adjustment process without alarms, without triggering protection, and with the hydrogen production pressure within the rated hydrogen production pressure boundary is selected. The current arrival time, current overshoot amplitude, current stabilization time, tank temperature change, cooling outlet temperature difference, temperature drop time, hydrogen production flow deviation, hydrogen production pressure fluctuation, and hydrogen production flow stabilization time are statistically analyzed. The more stringent set of values ​​between the manufacturer's technical manual's allowable values ​​and the on-site commissioning safety values ​​is used as the corresponding boundaries.

[0052] S2.5 When the current response level is high, the temperature recovery level is high, and the hydrogen production fluctuation level is low, the corresponding electrolyzer is classified as a high ramp-up capability level; when the current response level is low, the temperature recovery level is low, or the hydrogen production fluctuation level is high, the corresponding electrolyzer is classified as a low ramp-up capability level.

[0053] S2.6 Arrange the electrolytic cells from high to low according to their climbing ability level, and arrange the electrolytic cells with the same climbing ability level from short to long according to their current stabilization time to obtain the electrolytic cell ability level sequence.

[0054] Specifically, if the current stabilization time is the same, they are arranged from shortest to longest temperature drop time; if the temperature drop time is still the same, they are arranged from shortest to longest hydrogen production flow stabilization time. For example, the ramp-up capability level and current stabilization time of the 6 electrolyzers are as follows: E01 is a high ramp-up capability level with a current stabilization time of 42s, E02 is a low ramp-up capability level with a current stabilization time of 68s, E03 is a high ramp-up capability level with a current stabilization time of 38s, E04 is a high ramp-up capability level with a current stabilization time of 45s, E05 is a low ramp-up capability level with a current stabilization time of 74s, and E06 is a low ramp-up capability level with a current stabilization time of 64s. Then the electrolyzer capability level sequence is E03, E01, E04, E06, E02, and E05.

[0055] It should be noted that this step incorporates the electrical response, thermal recovery, and hydrogen production stabilization process of the electrolyzer into the same ramp-up capability level classification process, so that the electrolyzer capability level sequence is no longer arranged solely based on rated power or manual experience. This solves the problem that different electrolyzers in multi-electrolyzer hydrogen production stations have different aging levels, cooling capacities, and hydrogen production stability, making it difficult to participate in a unified switching order. This allows subsequent candidate switching queues to prioritize electrolyzers that match the residual power slope level, reducing the impact of rapid switching on the electrolyzer plates, power modules, and gas-liquid separation units.

[0056] S3. Based on the residual power slope level in the wind and solar residual power index, include electrolyzers with the corresponding ramp-up capability level in the electrolyzer capacity level sequence into the candidate switching queue. Note that the following should be noted in this step: S3.1 Extract the surplus power slope level and absorbable power range from the wind and solar surplus power index, and determine the target climbing ability level according to the surplus power slope level.

[0057] Specifically, the electrolytic cell group control unit first obtains the wind and solar surplus power index corresponding to the current continuous change segment, and then extracts the surplus power slope level, absorbable power range, and switching direction from the wind and solar surplus power index; when the surplus power slope level is a rapidly rising surplus power slope level or a rapidly falling surplus power slope level, it indicates that the wind and solar surplus power has changed significantly in a short period of time, and the target climbing ability level is determined to be a high climbing ability level; when the surplus power slope level is a slowly rising surplus power slope level, a slowly falling surplus power slope level, or a stable surplus power slope level, it indicates that the rate of change of wind and solar surplus power is low or in a small oscillation state, and the target climbing ability level is determined to be a low climbing ability level.

[0058] Preferably, the above treatment prioritizes electrolyzers with fast response speed, good thermal recovery capability, and small hydrogen production fluctuations for rapidly changing residual power, and prioritizes electrolyzers with low ramp-up capability for slowly changing residual power, thereby reducing the long-term occupation of electrolyzers with high ramp-up capability.

[0059] S3.2 When the residual power slope level is a rapidly rising residual power slope level or a rapidly falling residual power slope level, the target climbing ability level is determined to be a high climbing ability level.

[0060] S3.3 When the residual power slope level is a gradually increasing residual power slope level, a gradually decreasing residual power slope level, or a stable residual power slope level, the target ramping capability level is determined to be a low ramping capability level; when the electrolyzers with low ramping capability level cannot cover the power absorption range, electrolyzers with high ramping capability level are added to the target ramping capability level.

[0061] In this embodiment, the inability of a low-climbing-capacity electrolytic cell to cover the absorbable power range means that the sum of the rated operating power, the current adjustable power margin, or the current adjustable power margin of a low-climbing-capacity electrolytic cell selected according to the electrolytic cell capacity level sequence is still less than the lower limit of the absorbable power range, or although it reaches the lower limit of the absorbable power range, it cannot reach 70% of the upper limit of the absorbable power range. In the commissioning scenario, the current adjustable power margin is the difference between the rated operating power and the current operating power of the electrolytic cell; in the dismantling scenario, the current adjustable power margin is... The power margin for reduction is the difference between the current operating power and the minimum stable operating power of the electrolyzer. When shutting down, it also includes the current operating power itself. For example, if the absorbable power range is 300kW to 900kW, the current adjustable power margins for low-climbing-capability electrolyzers E02 and E05 are 180kW and 200kW respectively, totaling 380kW. Although this reaches the lower limit of 300kW, it does not reach 70% of the upper limit of 900kW, that is, it does not reach 630kW. Therefore, it is determined that the low-climbing-capability electrolyzers cannot cover the absorbable power range.

[0062] Furthermore, when electrolyzers with low ramp-up capability levels cannot cover the absorbable power range, electrolyzers with high ramp-up capability levels are added to the target ramp-up capability level. Specifically, this includes: first, retaining the selected low ramp-up capability level electrolyzers, and then adding high ramp-up capability level electrolyzers from the electrolyzer capability level sequence in order of arrangement, until the total adjustable power of the candidate electrolyzers reaches the lower limit of the absorbable power range and approaches the upper limit of the absorbable power range; if the total adjustable power of the candidate electrolyzers exceeds the upper limit of the absorbable power range, then the last added high ramp-up capability level electrolyzer is marked as a power-limited switching target, and its switching power does not exceed the remaining power of the absorbable power range.

[0063] Preferably, by prioritizing the use of electrolyzers with lower ramping capacity to undertake relatively gentle power regulation tasks under conditions of gradual rise, gradual fall, or stability, and supplementing them with electrolyzers with higher ramping capacity when the power coverage of the lower ramping capacity electrolyzers is insufficient, the problem of wind and solar surplus power abandonment or DC bus power imbalance is avoided.

[0064] S3.4 Select electrolytic cells from the electrolytic cell capacity level sequence that are consistent with the target ramp-up capacity level and whose rated operating power falls within the absorbable power range, and include them in the candidate switching queue according to the order of arrangement in the electrolytic cell capacity level sequence.

[0065] Specifically, for electrolyzers with rated operating power higher than the upper limit of the absorbable power range but allowed to operate at partial load, if their minimum stable operating power is not higher than the upper limit of the absorbable power range, they can be included in the candidate switching queue, and their candidate switching power is limited to the absorbable power range. For electrolyzers with rated operating power lower than the lower limit of the absorbable power range, they are only included in the candidate switching queue if they can cover the absorbable power range when combined with other candidate electrolyzers. For example, the surplus power slope level in the wind and solar surplus power index is the rapid surplus power slope level, the absorbable power range is 300kW to 1185kW, and the electrolyzer capacity level sequence is E03, E01, etc. E04, E06, E02, and E05, with E03, E01, and E04 being high ramp-up capability levels. The rated operating power of each of the three electrolytic cells is 1000kW, and the minimum stable operating power is 300kW. Therefore, the candidate switching queue is arranged as E03, E01, and E04. If E03 is put into operation from 300kW to 1000kW and still cannot absorb all the remaining power, then E01 will continue to be selected to undertake the power regulation task of the remaining 185kW to 885kW. However, the actual input power of E01 must not be lower than 300kW. Therefore, the group control unit will synchronously adjust the power allocation of E03 and E01 so that both are above the minimum stable operating power.

[0066] It should be noted that this step converts the residual power slope level in the wind and solar residual power index into a selection rule for the electrolyzer's ramp-up capability level, and constrains the power adaptation relationship of candidate electrolyzers through the power absorption range. This solves the problem of the lack of a correspondence between the changes in the wind and solar residual power slope and the ramp-up capability level of the electrolyzer. It makes the switching targets in the rapid rise and fall state more inclined to electrolyzers with high ramp-up capability level, and makes the switching targets in the slow rise, slow fall and stable state more inclined to electrolyzers with low ramp-up capability level, thereby improving the balance of electrolyzer resource utilization and reducing the over-use of high ramp-up capability level electrolyzers.

[0067] S4. Based on the continuous operating status and most recent switching status of each electrolytic cell in the candidate switching queue, adjust the sorting position of the candidate switching queue to obtain the electrolytic cell switching sorting result. Note that the following should be noted in this step: S4.1 Determine the continuous running time, continuous downtime, most recently started status, and most recently stopped status of each electrolytic cell from the candidate start-up queue.

[0068] Specifically, the continuous operating time is the length of time the electrolytic cell has been continuously in operation from the moment it last transitioned from a shutdown or hot standby state to the current time in the sequence. If the current falls below the shutdown current boundary for 60 seconds during operation, the continuous operating time is recalculated. The continuous shutdown time is the length of time the electrolytic cell has been continuously in shutdown or hot standby from the moment it last transitioned from operation to shutdown or hot standby state to the current time in the sequence. If the current enters the rated current boundary for 60 seconds during shutdown, the continuous shutdown time is recalculated. The most recently activated state is based on the most recently activated time, The most recent start-up state is determined by the shutdown duration before start-up, the current stabilization state after start-up, and the hydrogen production stabilization state after start-up. If the corresponding electrolyzer was recently switched to start-up before the current sorting time, and both the current stabilization state and the hydrogen production stabilization state after start-up have been formed, then the electrolyzer is considered to be in the most recent start-up state. The most recent cut-off state is determined by the most recent cut-off time, the running time before the most recent cut-off, the temperature drop state after cut-off, and the current returning to zero state after cut-off. If the corresponding electrolyzer was recently switched to cut-off before the current sorting time, and the temperature drop state or the current returning to zero state after cut-off has not yet fully met the corresponding shutdown boundary, then the electrolyzer is considered to be in the most recent cut-off state.

[0069] For example, if the current sorting time is 10:30:00, and E03 switches from hot standby to operating status at 09:50:00, and there is no instance of current falling below the shutdown current boundary for 60 seconds between 09:50:00 and 10:30:00, then the continuous operating time of E03 is 40 minutes. If E05 switches from operating status to hot standby status at 10:05:00, and there is no instance of current entering the rated current boundary for 60 seconds between 10:05:00 and 10:30:00, then the continuous shutdown time of E05 is 25 minutes. If E06 switches from shutdown to operating status at 10:18:00, and the current sorting time is 10:30:00, then the continuous operating time of E06 is 12 minutes. The system's current stabilization status and hydrogen production stabilization status after startup are considered to determine if it is in a recently started state.

[0070] Furthermore, the most recent commissioning status includes the most recent commissioning time, the shutdown duration before the most recent commissioning, the current stabilization status after commissioning, and the hydrogen production stabilization status after commissioning. The most recent commissioning time is the moment when the corresponding electrolyzer transitions from a shutdown or hot standby state to an operating state. The shutdown duration before the most recent commissioning is the length of time the corresponding electrolyzer was continuously in a shutdown or hot standby state before the most recent commissioning time. The current stabilization status after commissioning is the state where the current regulation curve of the corresponding electrolyzer reaches the rated operating boundary after the most recent commissioning time. The hydrogen production stabilization status after commissioning is the state where the hydrogen production flow rate of the corresponding electrolyzer reaches the rated operating boundary after the most recent commissioning time. The most recent cut-off status includes the most recent cut-off time, the running time before the most recent cut-off, the temperature drop status after the cut-off, and the current returning to zero after the cut-off. Among them, the most recent cut-off time is the moment when the corresponding electrolytic cell changes from the running state to the shutdown state or hot standby state; the running time before the most recent cut-off is the length of time that the corresponding electrolytic cell was continuously in the running state before the most recent cut-off time; the temperature drop status after the cut-off is the state in which the temperature of the corresponding electrolytic cell enters the shutdown temperature boundary after the most recent cut-off time; and the current returning to zero after the cut-off is the state in which the current value of the corresponding electrolytic cell enters the shutdown current boundary after the most recent cut-off time.

[0071] S4.2. Classify and correct the electrolytic cells in the candidate switching queue according to the order of input retention, cut-off shift, operation forward, and sequence preservation; wherein, the latter category is determined only from electrolytic cells that have not been included in the former category.

[0072] In this embodiment, the "put-in and hold" category corresponds to electrolytic cells that have just been put into operation and have not yet reached the continuous operation boundary; the "cut-off and move" category corresponds to electrolytic cells that have just been cut off and have not yet reached the continuous shutdown boundary; the "run-forward" category corresponds to electrolytic cells that have been running continuously and are suitable for receiving slowly rising or stable residual power; and the "sequence preservation" category corresponds to electrolytic cells that do not meet the above three types of correction rules.

[0073] By following the above sequence, the same electrolytic cell is assigned to only one category in a single sorting and correction process, thus avoiding unclear sorting boundaries caused by the same electrolytic cell simultaneously satisfying multiple correction rules.

[0074] S4.3. Electrolyzers that are in the most recently started state and whose continuous running time has not reached the continuous running boundary are classified as start-up holding cells, and their current position in the start-up and switching sorting is retained.

[0075] In this embodiment, the continuous operation boundary is set at 30 minutes. The continuous operation boundary is determined by the shortest safe operating time required for the electrolyzer to achieve stable current, stable hydrogen production flow, and stable tank temperature after being put into operation. After a 1000kW alkaline electrolyzer is put into operation, the current recovery time is no more than 60 seconds, the hydrogen production flow recovery time is no more than 120 seconds, and the tank temperature typically takes 15 to 25 minutes to enter a stable change range. At the same time, in order to avoid current fluctuations and gas-liquid separation pressure disturbances caused by the immediate adjustment of the electrolyzer after it has been put into operation, the continuous operation boundary is set at 30 minutes. When an electrolyzer in the candidate switching queue is in the most recently put-in state and its continuous operation time has not reached 30 minutes, the electrolyzer is classified as a put-in retention class, and its current position in the switching order is retained to prevent the electrolyzer from being prematurely moved back or switched to other adjustment positions due to the order correction immediately after it has been put into operation.

[0076] S4.4. Electrolytes that are not included in the input-maintain category, are in the most recently cut-off state, and whose continuous downtime has not reached the continuous downtime boundary are classified as cut-off shifted categories, and their positions in the input-output sorting are shifted to the back.

[0077] In this embodiment, the continuous shutdown boundary is set at 20 minutes. The continuous shutdown boundary is determined based on the shortest safe shutdown time required for the current to return to zero, the tank temperature to drop, and the gas-liquid side pressure to recover after the electrolyzer is disconnected. After a 1000kW alkaline electrolyzer is disconnected, it typically takes 60 to 120 seconds for the current to reach the shutdown current boundary, 10 to 18 minutes for the tank temperature to drop to the shutdown temperature boundary, and 5 to 12 minutes for the hydrogen production side pressure to recover to the shutdown pressure range. Considering the above recovery process, the continuous shutdown boundary is set at 20 minutes. When an electrolyzer in the candidate switching queue is not included in the switching-in retention category, is in the most recently disconnected state, and the continuous shutdown time has not reached 20 minutes, the electrolyzer is classified as a disconnection-postponed category, and its position in the switching order is moved to the back. This avoids the electrolyzer being re-connected when it has just been disconnected and the hot and gas-liquid states have not yet recovered, thus reducing electrode polarization shocks and hydrogen production pressure fluctuations caused by frequent start-ups and shutdowns.

[0078] S4.5. Electrolyzers that are not included in the "Input-Maintain" or "Remove-After-Cut" categories, are in continuous operation, and whose residual power slope level in the wind and solar residual power index is a gradually increasing residual power slope level or a stable residual power slope level are classified as "Move-Forward" categories, and their positions in the switching order are moved forward. Electrolyzers that are not included in the "Input-Maintain", "Remove-After-Cut", or "Move-Forward" categories are classified as "Order-Preserving" categories, and their relative order in the candidate switching queue is preserved. The electrolyzers in the candidate switching queue are arranged according to the corrected sorting position to obtain the electrolyzer switching order result.

[0079] Preferably, when surplus wind and solar power is slowly increasing or approaching a stable level, priority is given to increasing the ranking of electrolytic cells that are already continuously operating and in a stable state, allowing them to absorb the increased surplus power through load adjustments, rather than prioritizing the startup of electrolytic cells that are currently shut down. For electrolytic cells that do not meet the conditions for maintaining operation, shifting off operation, or shifting forward operation, their relative order in the candidate switching queue is retained, ensuring that the candidate switching queue remains in a complete ranking after state correction. This reduces the number of electrolytic cell startups and minimizes abrupt changes in DC bus power distribution.

[0080] In a specific example, a wind-solar-hydropower hybrid electrolysis hydrogen production station with weak grid connection is equipped with six 1000kW electrolyzers, numbered E01 to E06. The minimum stable operating power of a single electrolyzer is 300kW. The current sorting time is 10:30:00. The wind and solar surplus power index shows a gradually increasing surplus power slope, with a power absorption range of 300kW to 900kW, and the switching direction is input. According to step S3, the initial order of the candidate switching queue is E06, E02, E05, and E03, where E06, E02, and E05 are... The low climbing ability level is defined as E03, which is a supplementary high climbing ability level. As determined by step S4.1: E06 was put into operation at 10:18:00, with a continuous running time of 12 minutes, and is in the most recently put-in state; E02 was put into operation at 09:20:00, with a continuous running time of 70 minutes, and is in a continuous running state, not in the most recently cut-off state; E05 was cut off at 10:15:00, with a continuous downtime of 15 minutes, and is in the most recently cut-off state; E03 was put into operation at 08:40:00, with a continuous running time of 110 minutes, and is in a continuous running state.

[0081] According to step S4.3, E06 is in the most recently put-in state and its continuous running time has not reached 30 minutes. E06 is classified as put-in and retained in the current position of E06 in the switching order. According to step S4.4, E05 is not classified as put-in and retained and is in the most recently cut-out state. Its continuous downtime has not reached 20 minutes. E05 is classified as cut-out moved-back and its position in the switching order is moved back. According to step S4.5, neither E02 nor E03 is classified as put-in and retained nor cut-out moved-back. Both are in continuous running state and their residual power slope level is the gradually increasing residual power slope level. E02 and E03 are classified as running forward and their positions in the switching order are moved forward. However, E03 belongs to the high ramp-up capability level of the supplementary system, and its forward position does not exceed that of E02, which has a low ramp-up capability level.

[0082] The final electrolytic cell switching order is E06, E02, E03, and E05. If the current operating power of E06 is 500kW, the current operating power of E02 is 650kW, and the current operating power of E03 is 700kW, then E06 can be increased to 800kW to absorb 300kW of surplus power, then E02 can be increased to 950kW to absorb 300kW of surplus power. If there is still surplus power, E03 can be increased to 1000kW to absorb 300kW of surplus power. E05 is ranked last because its continuous shutdown time is less than 20 minutes and it will not participate in this priority switching.

[0083] Preferably, this embodiment further classifies and corrects the sorting position based on the continuous operation status and recent switching status of the electrolyzer after the candidate switching queue has been formed. This ensures that the switching order simultaneously considers the needs for residual power absorption, electrolyzer state recovery, and operational stability. This solves the problem that sorting solely by ramp-up capability level may lead to rapid reactivation of recently disconnected electrolyzers, repeated short-term adjustments of newly activated electrolyzers, and the underutilization of stable electrolyzers. The electrolyzer switching order is more in line with the engineering constraints of current stabilization, temperature drop, and stable hydrogen production pressure, reducing the impact of frequent start-ups and shutdowns on electrolyzer lifespan and hydrogen production stability.

[0084] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for scheduling and switching based on wind and solar surplus power index, characterized in that, include: Based on the direction, magnitude, and duration of power changes in wind power surplus electricity and photovoltaic surplus electricity, surplus electricity slope levels are classified, and a wind and solar surplus electricity index is generated by combining the power absorption range. The generation of the wind and solar surplus power index includes: adding the wind surplus power sequence and the photovoltaic surplus power sequence at the same sampling time to obtain a total surplus power sequence; subtracting the power values ​​at adjacent sampling times in the total surplus power sequence to obtain an adjacent power difference sequence, and determining the direction of surplus power change according to the positive or negative state of the adjacent power difference sequence; grouping the sampling times with the same direction of surplus power change into continuous change segments, and determining the surplus power change amplitude and surplus power duration state according to the power value at the beginning and end of the continuous change segment and the segment length; classifying the surplus power slope level of the continuous change segment according to the ratio of the surplus power change amplitude to the surplus power duration state; delineating the absorbable power range according to the power value at the end of the continuous change segment and the minimum stable operating power of the electrolyzer, and establishing the correspondence between the surplus power slope level and the absorbable power range to obtain the wind and solar surplus power index; Based on the current response state, temperature recovery state, and hydrogen production fluctuation state of the electrolyzer, the electrolyzer ramp-up capability level is classified, and the electrolyzer capability level sequence is obtained by arranging the electrolyzer ramp-up capability levels. The process of obtaining the electrolyzer capacity level sequence includes: determining the current arrival time, current overshoot amplitude, and current stabilization time from the current regulation curve during the load regulation process according to the electrolyzer number to obtain the current response state; obtaining the temperature recovery state based on the tank temperature change, cooling outlet temperature difference, and temperature drop time before and after the load regulation process; obtaining the hydrogen production fluctuation state based on the hydrogen production flow rate deviation, hydrogen production pressure fluctuation, and hydrogen production flow rate stabilization time before and after the load regulation process; and comparing the current response state, the temperature recovery state, and the hydrogen production fluctuation state with the rated operating boundary of the electrolyzer to obtain the current response level and the temperature recovery level. The electrolyzers are classified into high ramp-up capability levels when the current response level is high, the temperature recovery level is high, and the hydrogen production fluctuation level is low. When the current response level is low, the temperature recovery level is low, or the hydrogen production fluctuation level is high, the corresponding electrolyzers are classified into low ramp-up capability levels. Electrolyzers are arranged from high to low ramp-up capability levels, and electrolyzers with the same ramp-up capability level are arranged from short to long current stabilization time to obtain an electrolyzer capability level sequence. Based on the residual power slope level in the wind and solar residual power index, the electrolyzers with the corresponding ramping ability level in the electrolyzer capacity level sequence are included in the candidate switching queue. Based on the continuous operating status and most recent switching status of each electrolytic cell in the candidate switching queue, the sorting position of the candidate switching queue is corrected to obtain the electrolytic cell switching sorting result.

2. The method for scheduling and switching based on wind and solar surplus power index according to claim 1, characterized in that, Determining the direction of residual power change based on the positive and negative states of the adjacent power difference sequence includes: When the adjacent power difference in the adjacent power difference sequence is positive, the direction of residual power change between adjacent sampling times corresponding to the adjacent power difference is determined as the upward direction. When the adjacent power difference in the adjacent power difference sequence is negative, the direction of residual power change between adjacent sampling times corresponding to the adjacent power difference is determined as the downward direction. When the adjacent power difference in the adjacent power difference sequence is zero, the direction of residual power change between adjacent sampling times corresponding to the adjacent power difference is determined as a stationary direction.

3. The method for scheduling and switching based on wind and solar surplus power index according to claim 1, characterized in that, The residual electric slope levels of the continuously varying segments are classified as follows: The slope value of a segment is obtained by the ratio of the power difference between the beginning and end of the continuously changing segment to the duration of the segment. When the slope value of the segment is within the boundary of a stable slope, the continuously changing segment is classified into a stable residual slope level. When the slope value of the segment is positive, and the slope value of the segment exceeds the steady slope boundary and reaches the steep slope boundary, the continuously changing segment is classified into a steep residual power slope level. When the slope value of the segment is positive, and the slope value of the segment exceeds the steady slope boundary but does not reach the steep slope boundary, the continuously changing segment is classified into a slow-rising residual power slope level. When the slope value of the segment is negative, and the magnitude of the descending slope determined by the slope value of the segment reaches the boundary of the steep descent slope, the continuously changing segment is classified into the steep descent residual power slope level. When the slope value of the segment is negative, and the slope value of the segment exceeds the steady slope boundary and the magnitude of the falling slope determined by the slope value of the segment does not reach the sharp falling slope boundary, the continuously changing segment is classified into a slow-falling residual power slope level. Wherein, when the slope value of a segment is negative, the magnitude of the slope value of the segment is used as the magnitude of the falling slope.

4. The method for scheduling and switching based on wind and solar surplus power index according to claim 1, characterized in that, The residual power variation amplitude includes the power difference between the beginning and end of the segment, the maximum power difference of the segment, and the average power difference of the segment; wherein, the power difference between the beginning and end of the segment is the difference between the power value at the end of the continuously changing segment and the power value at the beginning; the maximum power difference of the segment is the difference between the maximum power value and the minimum power value within the continuously changing segment; and the average power difference of the segment is the average value of the power difference between adjacent sampling times within the continuously changing segment. The residual charge duration includes the segment duration and the number of consecutive changes in the same direction; wherein, the segment duration is the time length between the first sampling time and the last sampling time within the continuous change segment; the number of consecutive changes in the same direction is the number of adjacent sampling times within the continuous change segment where the residual charge change direction is continuously consistent.

5. The method for scheduling and switching based on wind and solar surplus power index according to claim 1, characterized in that, The obtained current response level, temperature recovery level, and hydrogen production fluctuation level include: When the current arrival time, current overshoot amplitude, and current stabilization time in the current response state are all within the current response boundary, the current response state is classified as a high current response level. When at least one of the current arrival time, current overshoot amplitude, and current stabilization time in the current response state exceeds the current response boundary, the current response state is classified as a low current response level. When the temperature change of the tank, the temperature difference of the cooling outlet, and the temperature drop time in the temperature recovery state are all within the temperature recovery boundary, the temperature recovery state is classified as a high temperature recovery level. When at least one of the following in the temperature recovery state—the change in tank temperature, the temperature difference at the cooling outlet, and the temperature drop time—exceeds the temperature recovery boundary, the temperature recovery state is classified as a low temperature recovery level. When the hydrogen production flow rate deviation, hydrogen production pressure fluctuation, and hydrogen production flow rate stabilization time in the hydrogen production fluctuation state are all within the hydrogen production fluctuation boundary, the hydrogen production fluctuation state is classified as a low hydrogen production fluctuation level. When at least one of the following in the hydrogen production fluctuation state—hydrogen production flow deviation, hydrogen production pressure fluctuation, and hydrogen production flow stabilization time—exceeds the hydrogen production fluctuation boundary, the hydrogen production fluctuation state is classified as a high hydrogen production fluctuation level.

6. The method for scheduling and switching based on wind and solar surplus power index according to claim 1, characterized in that, Electrolyzers with the corresponding ramp-up capability level in the electrolyzer capability level sequence are included in the candidate switching queue, including: Extract the surplus power slope level and absorbable power range from the surplus power index, and determine the target climbing ability level according to the surplus power slope level; When the residual power slope level is a rapidly rising residual power slope level or a rapidly falling residual power slope level, the target climbing ability level is determined as a high climbing ability level. When the residual power slope level is a gradually increasing residual power slope level, a gradually decreasing residual power slope level, or a stable residual power slope level, the target ramping capability level is determined as a low ramping capability level; when the electrolyzer with a low ramping capability level cannot cover the absorbable power range, an electrolyzer with a high ramping capability level is added to the target ramping capability level. Electrolytes that match the target ramp-up capability level and whose rated operating power falls within the absorbable power range are selected from the electrolyzer capacity level sequence and listed in the candidate switching queue according to the order in the electrolyzer capacity level sequence.

7. The method for scheduling and switching based on wind and solar surplus power index according to claim 6, characterized in that, The obtained electrolytic cell switching and sorting results include: The continuous running time, continuous downtime, most recently started state, and most recently stopped state of the electrolytic cell are determined one by one from the candidate start-up queue. The electrolytic cells in the candidate switching queue are classified and corrected according to the order of input retention, cut-off shift, operation forward, and sequence preservation. Electrolyzers that are currently in the most recently started state and whose continuous running time has not reached the continuous running boundary are classified as the start-up retention class, and their current position in the start-up sorting is retained. Electrolytic cells that are not included in the aforementioned input-hold category, are in the most recently cut-off state, and whose continuous downtime has not reached the continuous downtime boundary are classified as the cut-off shift category, and their positions in the input-cut-off sorting are shifted to the later stage. Electrolyzers that are not listed in the input-maintain category and the cut-off-shift category, are in continuous operation, and whose residual power slope level in the wind and solar residual power index is a slowly rising residual power slope level or a stable residual power slope level are listed as the operation-forward shift category, and their positions in the input-output sorting are moved forward. Electrolytes not included in the input retention class, the cut-off shift class, and the operation forward class are classified as the order preservation class, and their relative order in the candidate input / cut-off queue is retained. The electrolytic cells in the candidate switching queue are arranged according to the corrected sorting position to obtain the electrolytic cell switching sorting result.

8. The method for scheduling based on wind and solar surplus power index according to claim 7, characterized in that, The most recent start-up status includes the most recent start-up time, the downtime before the most recent start-up, the current stabilization status after start-up, and the hydrogen production stabilization status after start-up; wherein, the most recent start-up time is the moment when the corresponding electrolyzer transitions from a downtime or hot standby state to an operating state; the downtime before the most recent start-up is the length of time the corresponding electrolyzer was continuously in a downtime or hot standby state before the most recent start-up time; the current stabilization status after start-up is the state where the current regulation curve of the corresponding electrolyzer reaches the rated operating boundary after the most recent start-up time; and the hydrogen production stabilization status after start-up is the state where the hydrogen production flow rate of the corresponding electrolyzer reaches the rated operating boundary after the most recent start-up time. The most recent cut-off state includes the most recent cut-off time, the running time before the most recent cut-off, the temperature drop state after cut-off, and the current returning to zero after cut-off; wherein, the most recent cut-off time is the moment when the corresponding electrolytic cell switches from the running state to the shutdown state or hot standby state; the running time before the most recent cut-off is the length of time that the corresponding electrolytic cell was continuously in the running state before the most recent cut-off time; the temperature drop state after cut-off is the state where the temperature of the corresponding electrolytic cell enters the shutdown temperature boundary after the most recent cut-off time; and the current returning to zero after cut-off is the state where the current value of the corresponding electrolytic cell enters the shutdown current boundary after the most recent cut-off time.

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