An EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen

Abstract

The invention relates to the technical field of energy management, and specifically discloses an EMS energy management system for photovoltaic off-grid coupled PEM water electrolysis hydrogen production, comprising: an energy acquisition module, which divides a PEM water electrolysis hydrogen production system into multiple units according to functions, and obtains time period allocation power; a power analysis module, which compares and analyzes the time period allocation power of the unit with the required power range, obtains the input over-energy unit, and determines whether the power matching of each unit needs to be analyzed; a model construction module, which constructs an energy efficiency evaluation model for each unit if the power matching of the unit needs to be analyzed; an energy efficiency analysis unit, which calculates an energy efficiency evaluation value and determines whether the input over-energy unit power needs to be regulated; an energy regulation module, which adjusts the input power if the input over-energy unit power needs to be regulated. The system can discover system stability problems in advance and optimize the power distribution of each unit of the PEM hydrogen production system.

Description

Technical Field

[0001] The present invention relates to the technical field of energy management, and in particular to an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen. Background Art

[0002] As a clean, efficient and sustainable energy carrier, the development and utilization of hydrogen energy has received increasing attention. In the photovoltaic off-grid coupled PEM water electrolysis hydrogen production system, energy management is crucial.

[0003] The existing technology often lacks an indicator to measure the overall matching of the power of each unit in the PEM water electrolysis hydrogen production system. The existing technology will focus on whether the power of a single unit is within the normal range, but lacks a comprehensive assessment of the coordination of the power distribution of the entire system, which makes it difficult to predict in advance the problems that may be caused by poor power matching during the operation of the system.

[0004] In terms of power regulation, the existing technologies often lack flexibility. When a deviation in unit power is found, it is not possible to perform scientific and reasonable regulation based on the energy efficiency of each unit in the system; for example, for an over-powered unit, the power may simply be reduced without considering the energy efficiency ratio of the unit and the energy demand of the entire system, which may lead to over-adjustment and affect production efficiency; for an under-powered unit, it is not possible to perform orderly and effective power supplementation based on its priority adjustment value, and it is impossible to achieve the optimal allocation of system energy.

[0005] To this end, the present invention provides an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen. Summary of the invention

[0006] The purpose of the present invention is to provide an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen, so as to solve the above-mentioned background problems.

[0007] Among them, EMS is Energy Management System, PEM is ProtonExchange Membrane, which means proton exchange membrane;

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] In the first aspect, the present invention provides an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen, comprising:

[0010] Energy acquisition module: The PEM water electrolysis hydrogen production system is divided into multiple units according to the difference in functions. During the monitoring period, the power of each unit is collected in real time. The time-based power distribution is obtained by analyzing the power of the unit in the time dimension, and the time-based power distribution is stored in the database.

[0011] Analysis and judgment module: obtain the time period allocation power of each unit from the database, compare and analyze the time period allocation power with the required power range, obtain the input over-energy unit and the input under-energy unit, perform numerical analysis on the time period allocation power of the input over-energy unit and the input under-energy unit, obtain the unit matching value Dp, and judge whether the power matching of each unit needs to be analyzed based on the unit matching value Dp;

[0012] Model building module: If the power matching of each unit needs to be analyzed, build energy efficiency evaluation models for the electrolyzer unit, gas separation unit, gas purification unit, and cooling unit;

[0013] Energy efficiency evaluation module: Based on the unit energy efficiency evaluation model, the unit energy efficiency ratio is obtained, and the unit energy efficiency ratio and the power deviation ratio of the input over-energy unit are numerically calculated to obtain the energy efficiency evaluation value Pg. Based on the energy efficiency evaluation value Pg, it is determined whether the time period allocation power of the input over-energy unit needs to be adjusted;

[0014] Energy regulation module: If the time period allocation power of the input over-energy unit needs to be adjusted, the input over-energy unit that needs to be adjusted is numerically calculated to obtain the power value to be adjusted. Based on the unit energy efficiency ratio of the input energy-deficient unit and the power deviation ratio of the input energy-deficient unit, a numerical analysis is performed to obtain the priority adjustment value, and a priority adjustment sequence is constructed. The first input energy-deficient unit is selected according to the priority adjustment sequence, and the input power of the input energy-deficient unit is adjusted through the numerical relationship between the first input energy-deficient unit and the power value to be adjusted.

[0015] In a second aspect, the present invention provides an EMS energy management method for off-grid photovoltaic coupled PEM water electrolysis hydrogen production, comprising:

[0016] Step 1: According to the difference in the functions of the PEM water electrolysis hydrogen production system, the system is divided into multiple units, the power of each unit is collected, and the power distribution in each time period is obtained by analyzing the power of the unit in the time dimension;

[0017] Step 2: Based on the time period allocation power of each unit, the time period allocation power of the unit is compared and analyzed with the corresponding required power range to obtain the input over-energy unit and the input under-energy unit, and the time period allocation power of the input over-energy unit and the input under-energy unit is numerically analyzed to obtain the unit matching value Dp. Based on the unit matching value Dp, it is determined whether the power matching of each unit needs to be analyzed;

[0018] Step 3: If the power matching of each unit needs to be analyzed, build an energy efficiency evaluation model for each unit;

[0019] Step 4: Based on the unit energy efficiency evaluation model, obtain the unit energy efficiency ratio, perform numerical calculation on the unit energy efficiency ratio and power deviation ratio of the input over-energy unit, obtain the energy efficiency evaluation value Pg, and determine whether the time period allocation power of the input over-energy unit needs to be adjusted based on the energy efficiency evaluation value Pg;

[0020] Step 5: If the time period allocation power of the input energy-overload unit needs to be adjusted, the priority adjustment value is obtained through numerical analysis based on the unit energy efficiency ratio of the input energy-deficient unit and the power deviation ratio of the input energy-deficient unit, and a priority adjustment sequence is constructed. According to the priority adjustment sequence, the input power of the input energy-deficient unit is adjusted.

[0021] Beneficial effects of the present invention:

[0022] The PEM water electrolysis hydrogen production system is divided into multiple units according to function, and the power allocated in each unit period is obtained and stored in real time. The analysis and judgment module then compares the power allocated in each unit period with the required power range to obtain the input over-power unit and the input under-power unit, and calculates the unit matching value Dp. The unit matching value is a comprehensive indicator to measure the overall matching of the power of each unit in the system, and can reflect the internal energy balance of the system. For example, when it is lower than the unit matching threshold, it indicates that there is a problem of uncoordinated power distribution in the system. For example, insufficient power of the electrolyzer unit will affect the hydrogen production, and excessive power of a unit will cause overload and overheating, affecting the stability of the system. By continuously monitoring the changes, possible problems with system stability can be discovered in advance, so that timely measures can be taken to ensure stable operation of the system.

[0023] Establish an energy efficiency evaluation model, obtain the unit energy efficiency ratio based on the energy efficiency evaluation model, calculate the priority adjustment value and construct a priority adjustment sequence according to the unit energy efficiency ratio and power deviation ratio of the input energy-deficient unit, orderly regulate the power of the input energy-deficient unit, fully consider the energy efficiency of each unit, scientifically and reasonably regulate the power, realize the optimal allocation of power, and improve the overall energy efficiency and performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] Figure 1 This is a flow chart of an energy acquisition and judgment method in an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis hydrogen production according to the present invention;

[0026] Figure 2 This is a flow chart of an energy efficiency analysis and control method in an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis hydrogen production according to the present invention;

[0027] Figure 3This is a system module diagram of an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen in the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1: Please refer to Figure 1 As shown, the present invention is an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen, comprising:

[0030] Energy acquisition module: The PEM water electrolysis hydrogen production system is divided into multiple units according to the difference in functions. During the monitoring period, the power of each unit is collected in real time. The time-based power distribution is obtained by analyzing the power of the unit in the time dimension, and the time-based power distribution is stored in the database.

[0031] The PEM water electrolysis hydrogen production system is divided into multiple units according to the difference in function. During the monitoring period, an ammeter and a voltmeter are installed at the input end of each unit to measure the current value and voltage value at the input end of the unit in real time.

[0032] The real-time current value and voltage value at the unit input end are multiplied to obtain the power of the unit;

[0033] The monitoring period is divided into multiple monitoring periods, and the unit power in each monitoring period is summed and averaged to obtain the period allocation power;

[0034] It should be noted that the time period allocation power is obtained by summing and averaging the power of a unit;

[0035] The time period allocation power of each unit is stored as data in a database;

[0036] In some embodiments, according to different functions of the PEM hydrogen production system, the PEM hydrogen production system is divided into an electrolyzer unit, a gas separation unit, a gas purification unit, and a cooling unit;

[0037] It should be noted that the functional differences of each unit of the PEM hydrogen production system are as follows: the electrolyzer unit converts electrical energy into chemical energy for the electrolysis of water to produce hydrogen and oxygen; the gas separation unit is used to separate the hydrogen and oxygen produced by electrolysis; the gas purification unit is used to adsorb and dry the gas; the cooling unit is used to cool the heat generated by the PEM hydrogen production system to prevent the PEM hydrogen production system from malfunctioning due to overheating;

[0038] Exemplarily, a high-precision ammeter and voltmeter are installed at the power input end of each unit to measure the actual input voltage U and current value I of the unit in real time, using the power formula: Get the time period allocated power P. For example, if the input voltage of the electrolytic cell unit is 2.1V and the input current is 550A, the time period allocated power is 1.15Kw;

[0039] Analysis and judgment module: obtain the time period allocation power of each unit from the database, compare and analyze the time period allocation power with the required power range, obtain the input over-energy unit and the input under-energy unit, perform numerical analysis on the time period allocation power of the input over-energy unit and the input under-energy unit, obtain the unit matching value Dp, and judge whether the power matching of each unit needs to be analyzed based on the unit matching value Dp;

[0040] Obtain the time period allocated power of each unit from the database, and compare the time period allocated power with the required power range corresponding to the unit;

[0041] It should be noted that for a 10-kW PEM electrolysis stack, the allowable fluctuation range of input power is 20% to 100%. The rated power of each unit and the allowable fluctuation range of input power are numerically calculated to obtain the required power range;

[0042] If the unit's time-period allocated power is within the required power range, no processing is performed;

[0043] If the time period allocated power of the unit is higher than the maximum endpoint value of the corresponding required power range, the unit is marked as an input over-power unit;

[0044] If the unit is lower than the minimum endpoint value of the corresponding required power range, the unit is marked as an input power-deficient unit;

[0045] Obtain the number of input over-energy units and the number of input under-energy units, and sum the number of input over-energy units and the number of input under-energy units to obtain the number of deviation units;

[0046] The number of deviation units is compared with the number of all units to obtain the deviation unit ratio, which is marked as Pc.

[0047] The time period allocated power of the input over-energy unit and the input under-energy unit is subtracted from the two end points of the required power range and the absolute value is taken, the obtained results are compared, and the smallest calculated result is selected as the power deviation value;

[0048] The power deviation value is ratioed with the length of the required power range to obtain a power deviation ratio;

[0049] Obtain the power deviation ratios of all input over-energy units and input under-energy units, sum and average the power deviation ratios of all input over-energy units and input under-energy units to obtain the mean value of the deviation ratio, and mark the mean value of the deviation ratio as Jz;

[0050] Calculate the unit matching value Dp based on the deviation unit ratio Pc and the deviation ratio mean Jz;

[0051] By formula: Get the unit matching value Dp, where a and b are proportional coefficients, a=0.636, b=0.364;

[0052] Compare the unit matching value Dp with the unit matching threshold;

[0053] If the unit matching value Dp is higher than the unit matching threshold, it indicates that the power distribution of each unit of the PEM water electrolysis hydrogen production is within the expected range, and the power matching of each unit does not need to be analyzed, but the change of the unit matching value Dp still needs to be continuously monitored;

[0054] If the unit matching value Dp is lower than the unit matching threshold, it means that the power matching of each unit of the PEM water electrolysis hydrogen production is outside the expected range, and the power matching of each unit needs to be analyzed;

[0055] It should be noted that the unit matching value Dp is a comprehensive indicator used to measure the overall matching of the power of each unit in the PEM water electrolysis hydrogen production system. In the PEM water electrolysis hydrogen production system, stable power distribution is crucial. The lower the unit matching value Dp, the more over-powered input units there are in the system or the power deviation of the units is large, which leads to the breakdown of the energy balance within the system. For example, if the power of the electrolyzer unit is insufficient, it may not be able to perform the electrolysis reaction at the expected rate, affecting the hydrogen production. If the power of a unit is too high, it may cause overload and overheating of the unit, thereby affecting the stability of the entire system. Through monitoring, possible problems with system stability can be discovered in advance.

[0056] For example, if the time period allocation power of the electrolytic cell unit, the gas separation unit, the gas purification unit, and the cooling unit are 12Kw, 1.8Kw, 0.25Kw, and 2.5kw, respectively, and the required power ranges of the electrolytic cell unit, the gas separation unit, the gas purification unit, and the cooling unit are [3Kw, 15Kw], [0.4Kw, 2Kw], [0.3Kw, 1.5Kw], and [0.6Kw, 3Kw], respectively, the deviation unit ratio Pc is calculated to be 0.250, the power deviation ratio Gn is 0.042, and the calculation formula of the unit matching value Dp is substituted to obtain the unit matching value Dp of 0.944;

[0057] The technical solution of this embodiment is: divide the PEM water electrolysis hydrogen production system into multiple units according to functional differences, collect the power of each unit in real time during the monitoring period, and obtain the time period allocated power by analyzing the power of the unit in the time dimension. The time period allocated power is stored in the database, so that possible problems with system stability can be discovered in advance, and the time period allocated power of each unit is obtained from the database. The time period allocated power is compared and analyzed with the required power range to obtain input over-energy units and input under-energy units. The time period allocated power of the input over-energy units and the input under-energy units is numerically analyzed to obtain the unit matching value Dp, and it is determined whether the power matching of each unit needs to be analyzed based on the unit matching value Dp.

[0058] Embodiment 2: Based on Embodiment 1, an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen also includes:

[0059] Model building module: If the power matching of each unit needs to be analyzed, build energy efficiency evaluation models for the electrolyzer unit, gas separation unit, gas purification unit, and cooling unit;

[0060] Extract the characteristic values ​​of each unit and construct the energy efficiency evaluation model of the electrolyzer unit, gas separation unit, gas purification unit and cooling unit;

[0061] Specifically, the energy efficiency evaluation model of each unit is constructed as follows:

[0062] S1. The energy efficiency model of the electrolyzer is constructed as follows: obtaining the flow value of the gas generated in the cathode area of ​​the electrolyzer unit in each monitoring period;

[0063] The gas flow value is calculated by the ideal gas state equation to obtain the amount of gas substance;

[0064] The gas energy is obtained by multiplying the amount of gas substance by the combustion heat of hydrogen;

[0065] It should be noted that a mass flow meter is installed on the outlet pipe of the cathode area of ​​the electrolyzer. During the monitoring period, the gas flow value of each detection period is obtained. Based on the gas flow value, the amount of gas substance is calculated in combination with the ideal gas state equation: , n is the amount of gas substance, p is the atmospheric pressure 101.325Kpa, T is the temperature 273.15K, t is the duration of the monitoring period, R is the ideal gas constant, R=8.341, the amount of gas substance n is calculated, since the gas is mainly composed of hydrogen, the heat of combustion of hydrogen is 285.8kJ / mol;

[0066] Obtain the time period allocated power of the electrolytic cell within the monitoring period, and multiply the time period allocated power by the duration of the monitoring period to obtain input energy;

[0067] The gas energy and the input energy are processed as a difference, and the result is processed as a ratio with the input energy to obtain the unit energy efficiency ratio of the electrolyzer;

[0068] S2. The energy efficiency model of the gas separation unit is constructed as follows:

[0069] Obtain the flow value of the gas entering the gas separation unit during the monitoring period, and multiply the flow value of the gas by the length of the monitoring period to obtain the input gas content;

[0070] Obtain the flow value of the gas output from the gas separation unit, multiply the flow value of the gas by the length of the monitoring period to obtain the separated gas content;

[0071] The separated gas content and the input gas content are processed as a difference, and the calculated result and the input gas content are processed as a ratio to obtain the unit energy efficiency ratio of gas separation;

[0072] It should be noted that the construction method of the energy efficiency model of the gas purification unit is the same as that of the gas separation unit. Here, only the construction method of the energy consumption model of the gas purification unit is described;

[0073] S3. The energy efficiency model of the cooling unit is constructed as follows:

[0074] Use the temperature sensor to obtain the temperature difference ∆T between the inlet and outlet of the cooling unit during each monitoring period, and use the heat calculation formula: Obtain the cooling energy Q of the cooling unit, where m is the mass of the coolant and c is the specific heat capacity of the coolant;

[0075] Obtain the time period allocation power of the cooling unit within the monitoring period, and multiply the time period allocation power of the cooling unit by the length of the monitoring period to obtain the cooling input energy;

[0076] The cooling energy and the cooling input energy are subjected to difference processing, and the obtained result is subjected to ratio processing to obtain the unit energy efficiency ratio of the cooling unit.

[0077] Example 3: Figure 2 As shown, an EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen also includes:

[0078] Energy efficiency analysis module: Based on the unit energy efficiency evaluation model, the unit energy efficiency ratio is obtained, and the unit energy efficiency ratio and power deviation ratio of the input over-energy unit are numerically calculated to obtain the energy efficiency evaluation value Pg. Based on the energy efficiency evaluation value Pg, it is determined whether the time period allocation power of the input over-energy unit needs to be adjusted;

[0079] Based on the energy efficiency evaluation model of the electrolyzer unit, gas separation unit, gas purification unit and cooling unit, the unit energy efficiency ratio of the input energy unit is obtained;

[0080] The unit energy efficiency ratio of the input over-energy unit and the power deviation ratio Gn are subtracted and the absolute value is taken to obtain the over-energy output difference;

[0081] The over-energy output difference and the power deviation are treated as ratios to obtain the over-energy output ratio;

[0082] Obtain the over-energy output ratio of all monitoring periods within the monitoring cycle, and put the over-energy output ratio of all monitoring periods into the data group as a data element;

[0083] The data elements in the data group are summed and averaged to obtain the mean value of over-energy output, which is marked as Gc;

[0084] Calculate the variance of the elements in the data set to obtain the excess output variance, and mark the excess output variance as Fc;

[0085] Based on the excess energy output mean Gc and the excess energy output variance Fc, the energy efficiency evaluation value Pg is calculated;

[0086] By formula: Obtain the energy efficiency evaluation value Pg, where c and d are proportional coefficients, c=0.642, d=0.358;

[0087] Compare the energy efficiency evaluation value Pg with the energy efficiency evaluation threshold;

[0088] If the energy efficiency evaluation value Pg ≥ the energy efficiency evaluation threshold, it indicates that the input over-energy unit has input more power than the actual required power, and the input over-energy unit produces more products, that is, the unit has a higher energy efficiency ratio, and there is no need to adjust the time period allocation power of the input over-energy unit;

[0089] If the energy efficiency evaluation value Pg is less than the energy efficiency evaluation threshold, it indicates that the input unit is over-energy, the input power exceeds the actual required power, and the over-energy input unit cannot produce more products, that is, the energy efficiency ratio of the unit is not high, and the time period allocation power of the over-energy input unit needs to be adjusted;

[0090] For example: if the energy efficiency ratio of the electrolytic cell unit is 0.6, the required power range of the electrolytic cell unit is [3Kw, 15Kw], and the time period allocated power is 16Kw, then the power deviation value is 1Kw, the power deviation ratio is 0.083, the over-energy output ratio is 6.203, and the data group obtained by 5 monitorings within the monitoring period is {6.203, 6.5, 5.8, 6.3, 6.0}. The calculated over-energy output mean is 6.161, and the over-energy output variance is 0.057. Through the calculation formula of the energy efficiency evaluation value Pg, the energy efficiency evaluation value of the electrolytic cell unit as the input over-energy unit is 3.964;

[0091] Energy regulation module: If the time period allocation power of the input over-energy unit needs to be regulated, the input over-energy unit that needs to be regulated is numerically calculated to obtain the power value to be regulated. Based on the unit energy efficiency ratio of the input energy-deficient unit and the power deviation ratio of the input energy-deficient unit, a priority adjustment value is obtained through numerical analysis, and a priority adjustment sequence is constructed. The first input energy-deficient unit is selected according to the priority adjustment sequence, and the input power of the input energy-deficient unit is regulated according to the numerical relationship between the first input energy-deficient unit and the power value to be regulated;

[0092] If the time period allocation power of the input over-energy unit needs to be adjusted, the input over-energy unit that needs to be adjusted is marked as a unit to be adjusted;

[0093] According to the power of the maximum endpoint value of the required power range, adjust the input power of the unit to be regulated;

[0094] The power deviation values ​​of all units to be regulated are summed to obtain the regulated power value;

[0095] It should be noted that by changing the duty cycle, conduction angle and other parameters of the power electronic converter, the output voltage and current can be adjusted, thereby allocating the power of different units to the unit to be regulated;

[0096] Obtain the power deviation ratio of the input energy-deficient unit, and mark the power deviation ratio of the input energy-deficient unit as Qn;

[0097] Obtain the unit energy efficiency ratio of the input energy-deficient unit, and mark the unit energy efficiency ratio of the input energy-deficient unit as Nx;

[0098] Calculate the priority adjustment value Yx based on the power deviation ratio Qn of the input energy-deficient unit and the unit energy efficiency ratio Nx of the input energy-deficient unit;

[0099] By formula: Get the priority adjustment value Yx, where e and f are proportional coefficients, e=0.818, f=0.182;

[0100] The priority adjustment values ​​Yx of the input energy-deficient units are placed into a priority adjustment sequence in descending order, and the input power of the input energy-deficient units is adjusted according to the order of the input energy-deficient units in the priority adjustment sequence;

[0101] The specific input power adjustment method is as follows;

[0102] Select the input energy-deficient unit with the smallest sequence number from the priority adjustment sequence. If the power value to be adjusted is higher than the energy-deficient adjustment difference, obtain power equal to the power deviation value of the input energy-deficient unit from the power value to be adjusted, and allocate it to the input energy-deficient unit.

[0103] If the power value to be regulated is lower than the power deviation value of the input energy-deficient unit, the input power of the input energy-deficient unit is regulated according to the power of the regulated power value;

[0104] The input power of the input energy-deficient unit is regulated in sequence according to the priority adjustment sequence;

[0105] It should be noted that the input power of the energy-deficient unit is regulated in the order of the priority adjustment sequence. After each adjustment, the power value to be regulated decreases in sequence. Since the input power of the photovoltaic off-grid coupled power generation system is limited, the priority of regulation is determined in the order of the priority adjustment sequence.

[0106] Exemplary: if the gas separation unit is an input energy-deficient unit, the time period allocated power is 0.3kW, the required power range is [0.4kW, 2kW], the power deviation value is 0.1kW, the power deviation ratio is 0.062, the unit energy efficiency ratio is 0.7, and the priority adjustment value is 2.35 calculated by the formula; if the gas separation unit is the first adjustment unit in the priority adjustment sequence, and the control power value is 1.5kW, then the 0.1kW of the gas separation unit power deviation value is changed from the control power value, and the output voltage and current can be adjusted by changing the duty cycle, conduction angle and other parameters of the power electronic converter, thereby realizing the power distribution of different units to the gas separation unit;

[0107] The technical solution of this embodiment is: based on the unit energy efficiency evaluation model, the unit energy efficiency ratio is obtained, the unit energy efficiency ratio and the power deviation ratio of the input over-energy unit are numerically calculated to obtain the energy efficiency evaluation value Pg, based on the energy efficiency evaluation value Pg, it is judged whether the time period allocation power of the input over-energy unit needs to be regulated, if the time period allocation power of the input over-energy unit needs to be regulated, the input over-energy unit that needs to be regulated is numerically calculated to obtain the power value to be regulated, based on the unit energy efficiency ratio of the input energy-deficient unit and the power deviation ratio of the input energy-deficient unit, a priority adjustment value is obtained through numerical analysis, and a priority adjustment sequence is constructed, the first input energy-deficient unit is selected according to the priority adjustment sequence, and the input power of the input energy-deficient unit is regulated through the numerical relationship between the first input energy-deficient unit and the power value to be regulated.

[0108] Embodiment 4: An EMS energy management method for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen, comprising:

[0109] Step 1: According to the difference in the functions of the PEM water electrolysis hydrogen production system, the system is divided into multiple units, the power of each unit is collected, and the power distribution in each time period is obtained by analyzing the power of the unit in the time dimension;

[0110] Step 2: Based on the time period allocation power of each unit, the time period allocation power of the unit is compared and analyzed with the corresponding required power range to obtain the input over-energy unit and the input under-energy unit, and the time period allocation power of the input over-energy unit and the input under-energy unit is numerically analyzed to obtain the unit matching value Dp. Based on the unit matching value Dp, it is determined whether the power matching of each unit needs to be analyzed;

[0111] Step 3: If the power matching of each unit needs to be analyzed, build an energy efficiency evaluation model for each unit;

[0112] Step 4: Based on the unit energy efficiency evaluation model, obtain the unit energy efficiency ratio, perform numerical calculation on the unit energy efficiency ratio and power deviation ratio of the input over-energy unit, obtain the energy efficiency evaluation value Pg, and determine whether the time period allocation power of the input over-energy unit needs to be adjusted based on the energy efficiency evaluation value Pg;

[0113] Step 5: If the time period allocation power of the input energy-overload unit needs to be adjusted, the priority adjustment value is obtained through numerical analysis based on the unit energy efficiency ratio of the input energy-deficient unit and the power deviation ratio of the input energy-deficient unit, and a priority adjustment sequence is constructed. According to the priority adjustment sequence, the input power of the input energy-deficient unit is adjusted.

[0114] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. An EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen, characterized by: include: Energy acquisition module: Based on the differences in the functions of the PEM water electrolysis hydrogen production system, the system is divided into multiple units, the power of each unit is collected, and the power allocated for each time period is obtained by analyzing the power of the unit in the time dimension; Analysis and judgment module: Based on the time period power allocation of each unit, the time period power allocation of the unit is compared and analyzed with the corresponding required power range to obtain the input over-energy unit and the input under-energy unit. The time period power allocation of the input over-energy unit and the input under-energy unit is numerically analyzed to obtain the unit matching value Dp. Based on the unit matching value Dp, it is judged whether the power matching of each unit needs to be analyzed; Model building module: If the power matching of each unit needs to be analyzed, build an energy efficiency evaluation model for each unit; Energy efficiency evaluation module: Based on the unit energy efficiency evaluation model, the unit energy efficiency ratio is obtained, and the unit energy efficiency ratio and power deviation ratio of the input over-energy unit are numerically calculated to obtain the energy efficiency evaluation value Pg. Based on the energy efficiency evaluation value Pg, it is determined whether the time period allocation power of the input over-energy unit needs to be adjusted; Energy regulation module: If the time period allocation power of the input over-energy unit needs to be adjusted, the priority adjustment value is obtained through numerical analysis based on the unit energy efficiency ratio and power deviation ratio of the input under-energy unit, and a priority adjustment sequence is constructed. According to the priority adjustment sequence, the input power of the input under-energy unit is adjusted; The method for determining whether the power matching of each unit needs to be analyzed is: Calculate the unit matching value Dp based on the deviation unit ratio Pc and the deviation ratio mean Jz; By formula: Get the unit matching value Dp, where a and b are proportional coefficients; If the unit matching value Dp is lower than the unit matching threshold, the power matching situation of each unit needs to be analyzed.

2. The EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis hydrogen production according to claim 1, characterized in that: The method for obtaining the power allocated in the time period is as follows: During the monitoring period, the current value and voltage value of the unit input terminal are measured in real time, and the current value and voltage value of the unit input terminal are multiplied to obtain the power of the unit; The monitoring cycle is divided into multiple monitoring time periods, and the unit power in each monitoring time period is summed and averaged to obtain the time period allocated power.

3. The EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen according to claim 1, characterized in that: The method for obtaining the input over-energy unit and the input under-energy unit is as follows: Obtain the time period allocated power of each unit, and compare the time period allocated power with the required power range corresponding to the unit; If the time period allocated power of the unit is higher than the maximum endpoint value of the corresponding required power range, the input over-power unit is marked as an input over-power unit; If the cell is below the minimum endpoint value of the corresponding required power range, the cell is marked as an input power-deficient cell.

4. The EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen according to claim 1, characterized in that: The deviation unit ratio is obtained as follows: Obtain the number of input over-energy units and the number of input under-energy units, and sum the number of input over-energy units and the number of input under-energy units to obtain the number of deviation units; The number of deviation units is ratioed to the number of all units to obtain the deviation unit ratio, which is marked as Pc.

5. The EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen according to claim 1, characterized in that: The deviation ratio mean value Jz is obtained as follows: The time period allocated power of the input over-energy unit and the input under-energy unit is subtracted from the two end points of the required power range and the absolute value is taken, the obtained results are compared, and the smallest calculated result is selected as the power deviation value; The power deviation value is ratioed with the length of the required power range to obtain a power deviation ratio; The power deviation ratios of all input over-energy units and input under-energy units are obtained, and the power deviation ratios of all input over-energy units and input under-energy units are summed and averaged to obtain the deviation ratio mean, which is marked as Jz.

6. The EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis hydrogen production according to claim 1, characterized in that: The method of constructing the energy efficiency evaluation model of each unit is as follows: The characteristic values ​​of each unit are extracted, and energy efficiency evaluation models of the electrolyzer unit, gas separation unit, gas purification unit, and cooling unit are constructed.

7. The EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen according to claim 6, characterized in that: The energy efficiency evaluation model of the electrolyzer unit is constructed as follows: Obtaining the flow value of the gas generated in the cathode area of ​​the electrolytic cell unit during each monitoring period; The gas flow value is calculated through the ideal gas state equation to obtain the amount of gas substance; The gas energy is obtained by multiplying the amount of gas substance by the combustion heat of hydrogen; Obtain the time period allocated power of the electrolytic cell within the monitoring period, and multiply the time period allocated power by the duration of the monitoring period to obtain input energy; The gas energy and the input energy are processed as a difference, and the result is processed as a ratio with the input energy to obtain the unit energy efficiency ratio of the electrolyzer.

8. The photovoltaic off-grid coupled PEM water electrolysis hydrogen production EMS energy management system according to claim 6, characterized in that: The energy efficiency model of the gas separation unit is constructed as follows: Obtain the flow value of the gas entering the gas separation unit during the monitoring period, and multiply the flow value of the gas by the length of the monitoring period to obtain the input gas content; Obtain the flow value of the gas output from the gas separation unit, multiply the flow value of the gas by the length of the monitoring period to obtain the separated gas content; The separated gas content and the input gas content are processed as a difference, and the calculated result and the input gas content are processed as a ratio to obtain the unit energy efficiency ratio of gas separation; The energy efficiency model of the gas purification unit is constructed in the following manner: based on the gas separation unit, the energy efficiency model of the gas purification unit is constructed.

9. The photovoltaic off-grid coupled PEM water electrolysis hydrogen production EMS energy management system according to claim 6, characterized in that: The energy efficiency model of the cooling unit is constructed as follows: Obtain the temperature difference ∆T between the inlet and outlet of the cooling unit during each monitoring period, using the heat calculation formula: Obtain the cooling energy Q of the cooling unit, where m is the mass of the coolant and c is the specific heat capacity of the coolant; Obtain the time period allocation power of the cooling unit within the monitoring period, and multiply the time period allocation power of the cooling unit by the length of the monitoring period to obtain the cooling input energy; The cooling energy and the cooling input energy are subjected to difference processing, and the obtained result is subjected to ratio processing to obtain the unit energy efficiency ratio of the cooling unit.

10. The EMS energy management system for off-grid photovoltaic coupled PEM water electrolysis to produce hydrogen according to claim 1, characterized in that: The method for determining whether the time period distribution power of the input over-energy unit needs to be adjusted is: Based on the excess energy output mean Gc and the excess energy output variance Fc, the energy efficiency evaluation value Pg is calculated; By formula: Obtain the energy efficiency evaluation value Pg, where g and d are proportional coefficients; If the energy efficiency evaluation value Pg is less than the energy efficiency evaluation threshold, the time period allocation power of the input over-energy unit needs to be adjusted.

11. The photovoltaic off-grid coupled PEM water electrolysis hydrogen production EMS energy management system according to claim 10, characterized in that: The method for obtaining the excess energy output mean value Gc is as follows: Based on the energy efficiency evaluation model of the electrolyzer unit, gas separation unit, gas purification unit and cooling unit, the unit energy efficiency ratio of the input energy unit is obtained; The unit energy efficiency ratio of the input over-energy unit and the power deviation ratio Gn are subtracted and the absolute value is taken to obtain the over-energy output difference; The over-energy output difference and the power deviation are treated as ratios to obtain the over-energy output ratio; Obtain the over-energy output ratio of all monitoring periods within the monitoring cycle, and put the over-energy output ratio of all monitoring periods into the data group as a data element; The data elements in the data group are summed and averaged to obtain the mean value of over-energy output, which is marked as Gc; The method for obtaining the excess energy output variance is as follows: The variance of the elements in the data set is calculated to obtain the excess output variance, which is labeled as Fc.

12. The photovoltaic off-grid coupled PEM water electrolysis hydrogen production EMS energy management system according to claim 1, characterized in that: The input power of the input energy-deficient unit is regulated in the following manner: Obtain the power deviation ratio of the input energy-deficient unit, and mark the power deviation ratio of the input energy-deficient unit as Qn; Obtain the unit energy efficiency ratio of the input energy-deficient unit, and mark the unit energy efficiency ratio of the input energy-deficient unit as Nx. Calculate the priority adjustment value Yx based on the power deviation ratio Qn of the input energy-deficient unit and the unit energy efficiency ratio Nx of the input energy-deficient unit; By formula: Get the priority adjustment value Yx, where e and f are proportional coefficients; The priority adjustment values ​​Yx of the input energy-deficient units are obtained in descending order, and the corresponding input energy-deficient units are put into the priority adjustment sequence, and the input power of the input energy-deficient units is adjusted according to the order of the input energy-deficient units in the priority adjustment sequence; Select the input energy-deficient unit with the smallest sequence number from the priority adjustment sequence. If the power value to be adjusted is higher than the energy-deficient adjustment difference, obtain power equal to the power deviation value of the input energy-deficient unit from the power value to be adjusted, and allocate it to the input energy-deficient unit. If the power value to be regulated is lower than the power deviation value of the input energy-deficient unit, the input power of the input energy-deficient unit is regulated according to the power equal to the regulated power value.

13. The photovoltaic off-grid coupled PEM water electrolysis hydrogen production EMS energy management system according to claim 12, characterized in that: The method for obtaining the control power value is: If the time period allocation power of the input over-energy unit needs to be adjusted, the input over-energy unit that needs to be adjusted is marked as a unit to be adjusted; According to the power of the maximum endpoint value of the required power range, adjust the input power of the unit to be regulated; The power deviation values ​​of all units to be regulated are summed up to obtain the regulated power value.

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