Direct-current micro-grid hydrogen production system

Abstract

The invention provides a direct-current micro-grid hydrogen production system, which comprises a renewable energy source unit, a hydrogen production device, a common direct-current bus and a smart energy management and control platform, and is characterized in that the renewable energy source unit and the hydrogen production device are connected with the common direct-current bus; the smart energy management and control platform is used for controlling the hydrogen production device to operate in a full-load state when the power generation power of the renewable energy source unit is greater than or equal to the maximum operation power of the hydrogen production device, and controlling the hydrogen production device to operate in a full-load state when the power generation power is less than the maximum operation power and greater than or equal to the minimum operation power of the hydrogen production device. And controlling the hydrogen production device to adjust the operation power based on the generation power. The problems that a traditional hydrogen production system mainly depends on traditional energy, so that environmental problems are aggravated, and potential safety hazards exist can be solved, an intermediate converter can be omitted, energy loss is reduced, and the economical efficiency is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production, and in particular to a direct current microgrid hydrogen production system. Background Art

[0002] The hydrogen production system is the process of electrolyzing water into hydrogen and oxygen, which can provide an important energy storage and conversion method for the renewable energy field.

[0003] At present, the existing hydrogen production system mainly relies on traditional energy, such as fossil fuels, which leads to a large amount of greenhouse gas emissions in the hydrogen production process, which not only aggravates environmental problems but also poses safety risks. Summary of the invention

[0004] The present invention provides a direct current microgrid hydrogen production system, which is used to solve the defect of the existing hydrogen production system in the prior art that the existing environmental problems are aggravated.

[0005] The present invention provides a direct current microgrid hydrogen production system, comprising:

[0006] A renewable energy unit, a hydrogen production device, a public DC bus and a smart energy management and control platform, wherein the renewable energy unit and the hydrogen production device are both connected to the public DC bus;

[0007] The smart energy management and control platform is used to control the hydrogen production device to operate at full load when the power generation power of the renewable energy unit is greater than or equal to the maximum operating power of the hydrogen production device, and to control the hydrogen production device to adjust the operating power based on the power generation power when the power generation power is less than the maximum operating power and greater than or equal to the minimum operating power of the hydrogen production device.

[0008] According to a DC microgrid hydrogen production system provided by the present invention, the smart energy management and control platform is also used for:

[0009] When the generated power is less than the minimum operating power of the hydrogen production device, the hydrogen production device is controlled to operate at the minimum operating power.

[0010] According to a DC microgrid hydrogen production system provided by the present invention, the system further includes a load unit and an energy storage device, and the smart energy management and control platform is also used for:

[0011] After controlling the hydrogen production device to operate at full load, when the difference between the generated power and the maximum operating power is greater than or equal to the operating power of the load unit, connecting the renewable energy unit and the load unit to operate the load unit;

[0012] After controlling the hydrogen production device to operate at full load, when the difference between the generated power and the maximum operating power is less than the operating power of the load unit, connecting the renewable energy unit and the energy storage device to charge the energy storage device.

[0013] According to a DC microgrid hydrogen production system provided by the present invention, the smart energy management and control platform is also used for:

[0014] After the renewable energy unit is connected to the energy storage device, when the SOC of the energy storage device is greater than a threshold, the renewable energy unit and the energy storage device are disconnected.

[0015] According to a DC microgrid hydrogen production system provided by the present invention, the smart energy management and control platform is also used for:

[0016] When the generated power is less than the minimum operating power and the electric energy corresponding to the current SOC of the energy storage device is greater than or equal to the electric energy required for the minimum operating power, the energy storage device is connected to the hydrogen production device so that the energy storage device provides the hydrogen production device with the electric energy corresponding to the operation at the minimum operating power.

[0017] According to a DC microgrid hydrogen production system provided by the present invention, the system also includes an AC public power grid, and the smart energy management and control platform is also used for:

[0018] When the generated power is less than the minimum operating power and the electric energy corresponding to the current SOC of the energy storage device is less than the electric energy required for the minimum operating power, the hydrogen production device is connected to the AC public power grid so that the AC public power grid provides electric energy for the hydrogen production device.

[0019] According to a DC microgrid hydrogen production system provided by the present invention, the smart energy management and control platform is also used for:

[0020] In the event of a failure of the renewable energy unit, the hydrogen production device is connected to the AC public power grid so that the AC public power grid provides electrical energy to the hydrogen production device.

[0021] According to a DC microgrid hydrogen production system provided by the present invention, the smart energy management and control platform is also used to: monitor the operating parameters of the renewable energy unit, the hydrogen production device, the load unit and the energy storage device.

[0022] According to a DC microgrid hydrogen production system provided by the present invention, when the hydrogen production device operates at full load, the voltage of the common DC bus is greater than or equal to the minimum starting voltage of the hydrogen production device.

[0023] According to a DC microgrid hydrogen production system provided by the present invention, the renewable energy unit includes a photovoltaic power generation unit and / or a wind power generation unit.

[0024] The DC microgrid hydrogen production system provided by the present invention provides the electric energy required for the operation of the hydrogen production device based on the renewable energy unit, thereby avoiding the problem that the traditional hydrogen production system mainly relies on traditional energy, which leads to aggravated environmental problems and potential safety hazards. In addition, the renewable energy unit and the hydrogen production device of the present invention are both connected to a common DC bus. Compared with AC power, DC power is simpler, more efficient, more stable and reliable to operate, and can save intermediate converters, reduce energy losses, and is more economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is one of the structural schematic diagrams of the DC microgrid hydrogen production system provided by the present invention;

[0027] Figure 2 This is the second structural schematic diagram of the DC microgrid hydrogen production system provided by the present invention;

[0028] Figure 3 This is one of the flow charts of the operation of the DC microgrid hydrogen production system provided by the present invention;

[0029] Figure 4 This is the second flow chart of the operation of the DC microgrid hydrogen production system provided by the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0031] At present, the existing hydrogen production system mainly relies on traditional energy, such as fossil fuels, which leads to a large amount of greenhouse gas emissions in the hydrogen production process, which not only aggravates environmental problems but also poses safety risks.

[0032] To this end, the present invention provides a direct current microgrid hydrogen production system. Figure 1This is one of the structural schematic diagrams of the DC microgrid hydrogen production system provided by the present invention, such as Figure 1 As shown, the system includes:

[0033] Renewable energy unit 101, hydrogen production device 102, public DC bus 103 and smart energy management and control platform 104, the renewable energy unit 101 and hydrogen production device 102 are connected to the public DC bus 103;

[0034] The smart energy management and control platform 104 is used to control the hydrogen production device 102 to operate at full load when the power generation power of the renewable energy unit 101 is greater than or equal to the maximum operating power of the hydrogen production device 102, and to control the hydrogen production device 102 to adjust the operating power based on the power generation power when the power generation power is less than the maximum operating power and greater than or equal to the minimum operating power of the hydrogen production device 102.

[0035] Here, the renewable energy unit 101 is used to generate electricity using renewable energy, such as photovoltaic power generation, wind power generation, etc. The hydrogen production device 102 is a device for producing hydrogen, which can be a water electrolysis hydrogen production device.

[0036] When the power generation power of the renewable energy unit 101 is greater than or equal to the maximum operating power of the hydrogen production device 102, it indicates that the power generation power of the renewable energy unit 101 is sufficient to support the hydrogen production device 102 to operate at the maximum operating power, that is, to operate at full load. When the power generation power is less than the maximum operating power and greater than or equal to the minimum operating power of the hydrogen production device 102, it indicates that the renewable energy unit 101 can support the hydrogen production device 102 to operate between the maximum operating power and the minimum operating power, so that the smart energy management and control platform 104 controls the hydrogen production device 102 to adjust the operating power based on the power generation power, that is, when the power generation power increases, the hydrogen production device 102 can increase the operating power, and when the power generation power decreases, the hydrogen production device 102 can reduce the operating power.

[0037] Optionally, the smart energy management and control platform 104 may monitor meteorological data related to renewable energy, and predict the power generation of the renewable energy unit 101 based on the meteorological data. For example, when the renewable energy unit 101 is a photovoltaic power generation unit, the meteorological data may include light, temperature, etc. When the renewable energy unit 101 is a wind power generation unit, the meteorological data may include wind speed, etc. The power generation predicted by the smart energy management and control platform 104 may be a range value of the power generation.

[0038] Optionally, the wind power generation unit may include a wind turbine generator set, and the power generation power P of the wind power generation unit wind Affected by real-time wind speed v t Influence, assuming the rated power of the wind turbine is P Nwind , rated wind speed is vN , the cut-in wind speed and cut-off wind speed are v in and v out When v t <v in or v out <v t When P wind =0; when v in ≤v t <v N When P wind =P wind,t ; When v N ≤v t ≤v out When P wind =P Nwind .

[0039] The DC microgrid hydrogen production system provided in the embodiment of the present invention provides the hydrogen production device 102 with the required electricity for operation based on the renewable energy unit 101, thereby avoiding the problem that the traditional hydrogen production system mainly relies on traditional energy, which leads to aggravated environmental problems and potential safety hazards. In addition, the renewable energy unit 101 and the hydrogen production device 102 in the embodiment of the present invention are both connected to the common DC bus 103. Since DC power is simpler, more efficient, more stable and reliable than AC power, it can save intermediate converters, reduce energy losses, and is more economical.

[0040] Based on the above embodiment, the smart energy management and control platform 104 is also used for:

[0041] When the generated power is less than the minimum operating power of hydrogen production device 102 , hydrogen production device 102 is controlled to operate at the minimum operating power.

[0042] Specifically, when the generated power is less than the minimum operating power, it indicates that the generated power of the renewable energy unit 101 is insufficient to support the operation of the hydrogen production device 102. At this time, an AC public power grid or an energy storage device can be used to provide electrical energy to the hydrogen production device 102 so that the hydrogen production device 102 can operate at the minimum operating power.

[0043] Based on any of the above embodiments, the system further includes a load unit 105 and an energy storage device 106, and the smart energy management and control platform 104 is further used for:

[0044] After controlling the hydrogen production device 102 to operate at full load, when the difference between the generated power and the maximum operating power is greater than or equal to the operating power of the load unit 105, connecting the renewable energy unit 101 and the load unit 105 to operate the load unit 105;

[0045] After the hydrogen production device 102 is controlled to operate at full load, when the difference between the generated power and the maximum operating power is less than the operating power of the load unit 105 , the renewable energy unit 101 and the energy storage device 106 are connected to charge the energy storage device 106 .

[0046] Specifically, the load unit 105 refers to a device that can consume or utilize electric energy, which may include a flexible load, a cut-off load, etc. The energy storage device 106 is a device for storing energy so as to release it to supply power when needed.

[0047] After controlling the hydrogen production device 102 to operate at full load, when the difference between the generated power and the maximum operating power is greater than or equal to the operating power of the load unit 105, it indicates that after the renewable energy unit 101 provides electrical energy for the hydrogen production device 102, the remaining generated power (the difference between the generated power and the maximum operating power) is sufficient to support the operation of the load unit 105. At this time, the renewable energy unit 101 and the load unit 105 can be connected so that the renewable energy unit 101 provides electrical energy for the operation of the load unit 105.

[0048] When the difference between the generated power and the maximum operating power is less than the operating power of the load unit 105, it indicates that after the renewable energy unit 101 provides electrical energy to the hydrogen production device 102, the remaining generated power cannot support the operation of the load unit 105. At this time, the renewable energy unit 101 and the energy storage device 106 can be connected, so that the renewable energy unit 101 can charge the energy storage device 106.

[0049] Based on any of the above embodiments, the smart energy management and control platform 104 is further used for:

[0050] After the renewable energy unit 101 is connected to the energy storage device 106 , when the SOC of the energy storage device 106 is greater than a threshold, the renewable energy unit 101 and the energy storage device 106 are disconnected.

[0051] Specifically, after the renewable energy unit 101 and the energy storage device 106 are connected, if the SOC (State of Charge) of the energy storage device 106 is greater than the threshold, it indicates that the energy storage device 106 is in a fully charged state, and the renewable energy unit 101 and the energy storage device 106 are disconnected at this time, so that the renewable energy unit 101 does not continue to charge the energy storage device 106. The threshold value may be 100%, and may also be set according to actual conditions, and the embodiment of the present invention does not specifically limit this.

[0052] Based on any of the above embodiments, the smart energy management and control platform 104 is further used for:

[0053] When the generated power is less than the minimum operating power and the electric energy corresponding to the current SOC of the energy storage device 106 is greater than or equal to the electric energy required for the minimum operating power, the energy storage device 106 is connected to the hydrogen production device 102 so that the energy storage device 106 provides the hydrogen production device 102 with the electric energy corresponding to the operation at the minimum operating power.

[0054] Specifically, when the generated power is less than the minimum operating power, and the electric energy corresponding to the current SOC of the energy storage device 106 is greater than or equal to the electric energy required for the minimum operating power, it indicates that the renewable energy unit 101 cannot support the hydrogen production device 102 to operate at the minimum operating power, but the energy storage device 106 can support the hydrogen production device 102 to operate at the minimum operating power. At this time, the energy storage device 106 and the hydrogen production device 102 can be connected so that the energy storage device 106 provides the hydrogen production device 102 with the corresponding electric energy to operate at the minimum operating power.

[0055] Based on any of the above embodiments, the system further includes an AC public grid 107, and the smart energy management and control platform 104 is further used for:

[0056] When the generated power is less than the minimum operating power and the electric energy corresponding to the current SOC of the energy storage device 106 is less than the electric energy required for the minimum operating power, the hydrogen production device 102 is connected to the AC public power grid 107 so that the AC public power grid 107 provides electric energy for the hydrogen production device 102.

[0057] Specifically, the AC public grid 107 refers to a power supply system that transmits electric energy from a power plant to end users through transmission lines, substations and distribution networks. In the AC public grid 107, electric energy is transmitted in the form of AC, mainly using AC voltage and frequency.

[0058] When the generated power is less than the minimum operating power and the electric energy corresponding to the current SOC of the energy storage device 106 is less than the electric energy required for the minimum operating power, it indicates that neither the renewable energy unit 101 nor the energy storage device 106 can support the hydrogen production device 102 to operate at the minimum operating power. At this time, the hydrogen production device 102 is connected to the AC public power grid 107, so that the AC public power grid 107 can provide the hydrogen production device 102 with the electric energy required for operating at the minimum operating power.

[0059] Based on any of the above embodiments, the smart energy management and control platform 104 is further used for:

[0060] In the event of a failure of the renewable energy unit 101 , the hydrogen production device 102 is connected to the AC public grid 107 , so that the AC public grid 107 provides electrical energy for the hydrogen production device.

[0061] Specifically, when the renewable energy unit 101 fails, it indicates that the renewable energy unit 101 cannot support the hydrogen production device 102 to operate at the minimum operating power. At this time, the hydrogen production device 102 is connected to the AC public power grid 107, so that the AC public power grid 107 can provide the hydrogen production device 102 with the required electrical energy when operating at the minimum operating power.

[0062] It should be noted that the hydrogen production device 102 can be connected to the AC public power grid 107 in the following special or extreme cases, so that the AC public power grid 107 can support the operation of the hydrogen production device 102 in special or extreme cases:

[0063] (1) At night, the energy storage device is charged by the AC public power grid 107; (2) The renewable energy unit 101 fails and cannot supply power; (3) In extreme weather, the power provided by the renewable energy unit 101 or the battery charge of the energy storage device 106 cannot meet the operation of the hydrogen production device 102 at the minimum load (i.e., the minimum operating power).

[0064] Based on any of the above embodiments, the smart energy management and control platform 104 is also used to monitor the operating parameters of the renewable energy unit 101 , the hydrogen production device 102 , the load unit 105 and the energy storage device 106 .

[0065] Specifically, Figure 2 As shown, the smart energy management and control platform 104 comprehensively optimizes the decision-making function, determines the output scenario according to the power forecast and the load-side demand, compares it with the real-time electricity price in the power market, sorts out multiple groups of variables of each subsystem, performs hierarchical decoupling, and implements optimized decisions.

[0066] Furthermore, the approximate time period standards for commercial electricity peak, flat and valley electricity prices are as follows: peak period: 8:00-11:30, 18:30-23:00; flat period: 7:00-8:00, 11:30-18:30; valley period: 23:00-7:00, taking into account the influence of sunlight on the power generation of the renewable energy unit 101, such as the photovoltaic power generation period is 7:00-17:00.

[0067] Furthermore, in combination with the peak power consumption assessment and the output of new energy sources, the smart energy management and control platform 104 can be controlled based on the following five states: state A to state E, where state A is 8:00-11:30, state B is 11:30-17:00, state C is 17:00-23:00, state D is 23:00-7:00, and state E is 7:00-8:00.

[0068] Furthermore, the smart energy management and control platform 104 automatically learns and updates its own algorithm strategy based on real-time online diagnostic monitoring of new data sets, such as comparing the time-of-use electricity price with the valley electricity price when the economic objective function is used.

[0069] In addition, the smart energy management and control platform 104 adopts a hierarchical control and multi-objective real-time online rolling optimization decision-making method. The specific hierarchical control is as follows:

[0070] The first control layer is the G(x) control layer:

[0071]

[0072] X=[X 1 ,X 2 ,X 3 …X n ] T

[0073] The second control layer is E i (x) Control layer, representing the various subsystems of the DC microgrid system, including the photovoltaic power generation unit E pv (x), wind power generation unit E wind (x), energy storage device E soc (x) Hydrogen production device E H2 (x), flexible load unit E L1 (x), other load units E L2 (x).

[0074]

[0075] The third control layer is x i (i=1、2···n) control layer, x i Determined by several controllable variables, Indicates the characteristic parameters of each subsystem, such as active power, reactive power, voltage / current amplitude, phase, frequency, imbalance, harmonics, etc.

[0076] x i,min ≤x i ≤x i,max

[0077] Furthermore, the embodiment of the present invention can optimize the DC microgrid hydrogen production system based on the conditional boundary value card edge, and there is a near-optimal boundary constant E ci , assuming E ci Value x 1 , x 2 The influence of two variables, about the constraint boundary value x 2 The confirmation method is as follows:

[0078] E i =E i (x)≤E ci =(x 1 ,x 2 )

[0079]

[0080]

[0081]

[0082] in, is the parameter x 2 The conditional boundary card edge value of .

[0083] Based on any of the above embodiments, when the hydrogen production device 102 operates at full load, the voltage of the common DC bus 103 is greater than or equal to the minimum starting voltage of the hydrogen production device 102 .

[0084] Specifically, when the power generation power of the renewable energy unit 101 is greater than the maximum operating power of the hydrogen production device 102, and the voltage of the common DC bus 103 is greater than or equal to the minimum starting voltage of the hydrogen production device 102, the hydrogen production device 102 operates at full load.

[0085] Optionally, when the renewable energy unit 101 includes a photovoltaic power generation unit and a wind power generation unit, the hydrogen production device 102 operates at full load when the power generation of the photovoltaic power generation unit and the wind power generation unit and the voltage of the common DC bus 103 satisfy the following formula:

[0086]

[0087] Among them, P pv,t Represents the power generation of the photovoltaic power generation unit, P wind,t Represents the power generated by the wind power generation unit, P H,max represents the maximum operating power of the hydrogen production device 102, U represents the voltage of the common DC bus 103, and U H,min Indicates the minimum starting voltage of the hydrogen production device 102, U H,max Indicates the maximum starting voltage of the hydrogen production device 102.

[0088] Based on any of the above embodiments, the renewable energy unit 101 includes a photovoltaic power generation unit 1011 and / or a wind power generation unit 1012 .

[0089] Specifically, the photovoltaic power generation unit 1011 refers to a device that converts solar energy into electrical energy, and the wind power generation unit 1012 refers to a device that converts wind energy into electrical energy.

[0090] In addition, if Figure 1As shown, the system also includes an MPTT controller 108, a DC / DC bidirectional converter 109, an AC / DC converter 1 110, an AC / DC converter 2 111, a battery management system 112, an AC / DC converter 3 113, an external power grid 114, QF1~QF11 are controlled switches, and the load unit 150 also includes a cut-off load unit 1051 and a flexible load unit 1052.

[0091] The photovoltaic strings in the photovoltaic power generation unit 1011 are connected in series or parallel in a certain arrangement, and then connected to the common DC bus 103 through a combiner box, a DC / DC converter 109 and a DC circuit breaker. The wind power generation unit 1012 generates AC power through an AC / DC bidirectional converter 113, and then connects it to the common DC bus 103 through a DC circuit breaker.

[0092] The smart energy management and control platform 104 has the functions of real-time online monitoring, renewable energy power prediction, model self-update mechanism, and comprehensive optimization decision-making.

[0093] The online monitoring function of the smart energy management and control platform includes real-time online monitoring of the output power of the DC / DC converter 109. Assuming that the DC / DC converter 109 has no power loss, the output power of the DC / DC converter 109 is equal to the power generation power of the photovoltaic power generation unit 1011, that is, P pv,t =P DC / DC ; Monitor the power generation P of wind power generation unit 1012 wind,t ; Hydrogen production device 102 power P H,t ; Energy storage device 106 state of charge percentage SOC t %; load unit 105 electric load power; real-time online monitoring of the operating status of each device; various AC and DC circuit breaker shutdown states, etc., as well as equipment voltage / current amplitude, phase, frequency, unbalance, harmonics and other power indicators.

[0094] The maximum output voltage of the photovoltaic power generation unit 1011 is less than the maximum input voltage limit of the DC / DC converter 109, that is, U pvmax DC / DCmax .

[0095] Furthermore, the battery management system 112 sets the initial SOC% of the battery state of charge of the energy storage device 102 to 100%. The battery operation state of charge has a critical upper and lower limit, namely, SOC min % <SOC t % <SOC max %. When the state of charge reaches its critical minimum value, the battery adjusts the working state to the charging state.

[0096] ​Furthermore, the smart energy management and control platform 104 has a self-update mechanism function, which can automatically learn and automatically update its own algorithm strategy based on real-time online diagnosis and monitoring of new data sets to adapt to new working environments.

[0097] Furthermore, the automatic learning and automatic updating of algorithm strategies can automatically switch and update the algorithm strategies for corresponding scenarios through data collection, data preprocessing, data analysis and processing.

[0098] Furthermore, based on the self-update mechanism, multi-objective real-time online rolling optimization should also be considered.

[0099] Furthermore, the MPPT controller 108 in the photovoltaic power generation unit 1011 can realize a multi-path optimization function, and after converging, the power is boosted through the DC / DC converter 109 and connected to a common DC bus.

[0100] Furthermore, the hydrogen production device 102 includes n hydrogen production electrolytic cell units, and the number of the electrolytic cell units is controlled by electric load according to the power generation status of the renewable energy unit 101.

[0101] Furthermore, the operating mode of the hydrogen production device 102 includes a rated operating state, an adjustable operating state, and a stopped operating state.

[0102] When the hydrogen production device 102 is in the adjustable operation mode, the adjustable hydrogen load range is αP NH <P H,t <P NH , where α∈(α min， 1), α min It can be determined by the performance of the manufacturer's hydrogen production device.

[0103] Furthermore, the maximum operating power P of the hydrogen production device 102 H,max =kP NH , k is the maximum adjustment coefficient of the hydrogen production device 102, which is generally about 1.2 to 1.5. This parameter can be adjusted according to the actual operation conditions. H,max Too low will cause the hydrogen production device 102 to switch frequently, affecting the stability of the system. H，max If it is too high, the system economy will be reduced.

[0104] Furthermore, the energy storage device 106 has a minimum charge limit. When the measured charge meets the SOC min %≥SOC t %, or during the off-peak period at night, QF10 and QF11 are turned on, and the energy storage device 106 is charged by the AC public grid 107 until SOC%=100%.

[0105] Furthermore, if Figure 3As shown, when the hydrogen production device 102 is running at full load, the surplus power is considered to supply other loads, that is, when the power generation power of the renewable energy unit 101 satisfies the following formula, QF 3 or QF 5 Turn on.

[0106]

[0107] Among them, P pv，t Represents the power generation of the photovoltaic power generation unit, P wind，t Represents the power generated by the wind power generation unit, P H，max represents the maximum operating power of the hydrogen production device 102, P L1 Indicates the operating power of load 1051 that can be cut off, P L2 It represents the operating power of the flexible load 1052. Among them, k is the maximum adjustment coefficient of the equipment operation, which is generally set to about 1.2 to 1.5. On the one hand, a certain margin is set for the surplus power, and on the other hand, it is considered not to cause frequent switching of the switch.

[0108] Furthermore, if Figure 3 As shown, when the difference between the power generation power of the renewable energy unit 101 and the maximum operating power of the hydrogen production device 102 is less than kP L1 or kP L2 When the following equation is satisfied, QF 9 The energy storage device 106 starts charging until SOC%=100%.

[0109] 0≤P pv，t +P wind，t -P H，max ≤kP L1 or

[0110] 0≤P pv，t +P wind，t -P H，max ≤kP L2

[0111] Furthermore, in order to avoid frequent switching of the working state of the hydrogen production device 102, a minimum time limit t is set for the time from the start-up of the electrolyzer of the hydrogen production device 102 to the time of maintaining the rated power stability. min .

[0112] Furthermore, when the sum of the power generated by the photovoltaic power generation unit 1011 and the wind power generation unit 1012 is greater than the minimum operating power αP of the hydrogen production device 102 NH and is less than the maximum operating power P of the hydrogen production device 102 H，max When P H，max ≥P pv，t +P wind，t≥αP NH When the hydrogen production device 102 follows the power generation of the photovoltaic power generation unit 1011 and the wind power generation unit 1012, the operating power is adjusted.

[0113] Furthermore, if Figure 4 As shown, when the sum of the power generated by the photovoltaic power generation unit 1011 and the wind power generation unit 1012 is less than the minimum operating power αP of the hydrogen production device 102 NH When P pv,t +P wind,t ≤αP NH And the SOC corresponding power of the energy storage device 106 is greater than or equal to the minimum operating power αP NH When QF8 and QF11 are turned on, the energy storage device 106 provides electric energy to enable the hydrogen production electrolyzer system to operate at the minimum power αP NH run.

[0114] Furthermore, there is an obvious isolation point between the DC microgrid hydrogen production system and the AC public power grid 107, namely the switch QF11, so as to play a role in supporting the large power grid in special or extreme circumstances.

[0115] Among them, special or extreme situations include but are not limited to the following situations: 1) the energy storage device 106 is charged using the AC public power grid 107 at night; 2) the renewable energy unit 101 fails and cannot supply power; 3) in extreme weather, the power provided by the renewable energy unit 101 or the battery charge of the energy storage device 106 cannot meet the minimum load operation of the hydrogen production device 102.

[0116] Compared with the prior art, the present invention has the following beneficial effects:

[0117] The present invention is based on the card edge optimization design system, and has the characteristics of hierarchical control, multi-objective real-time online rolling optimization decision-making, etc. It is an effective strategy for realizing the DC microgrid hydrogen production system for renewable energy power generation. The AC system needs to control the amplitude, frequency, and phase. Compared with the AC system, DC power only needs to control the voltage amplitude, and the system operation is simpler, more efficient, stable, and reliable. At the same time, the DC microgrid system only needs one level of voltage conversion, which greatly saves a lot of intermediate converter links, reduces energy loss, and is more economical.

[0118] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0119] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A direct current microgrid hydrogen production system, characterized in that: include: A renewable energy unit, a hydrogen production device, a public DC bus and a smart energy management and control platform, wherein the renewable energy unit and the hydrogen production device are both connected to the public DC bus; The smart energy management and control platform is used to control the hydrogen production device to operate at full load when the power generation power of the renewable energy unit is greater than or equal to the maximum operating power of the hydrogen production device, and to control the hydrogen production device to adjust the operating power based on the power generation power when the power generation power is less than the maximum operating power and greater than or equal to the minimum operating power of the hydrogen production device.

2. The DC microgrid hydrogen production system according to claim 1, characterized in that: The smart energy management and control platform is also used for: When the generated power is less than the minimum operating power of the hydrogen production device, the hydrogen production device is controlled to operate at the minimum operating power.

3. The DC microgrid hydrogen production system according to claim 2, characterized in that: The system also includes a load unit and an energy storage device, and the smart energy management and control platform is also used for: After controlling the hydrogen production device to operate at full load, when the difference between the generated power and the maximum operating power is greater than or equal to the operating power of the load unit, connecting the renewable energy unit and the load unit to operate the load unit; After controlling the hydrogen production device to operate at full load, when the difference between the generated power and the maximum operating power is less than the operating power of the load unit, connecting the renewable energy unit and the energy storage device to charge the energy storage device.

4. The DC microgrid hydrogen production system according to claim 3, characterized in that: The smart energy management and control platform is also used for: After the renewable energy unit is connected to the energy storage device, when the SOC of the energy storage device is greater than a threshold, the renewable energy unit and the energy storage device are disconnected.

5. The DC microgrid hydrogen production system according to claim 3, characterized in that: The smart energy management and control platform is also used for: When the generated power is less than the minimum operating power and the electric energy corresponding to the current SOC of the energy storage device is greater than or equal to the electric energy required for the minimum operating power, the energy storage device is connected to the hydrogen production device so that the energy storage device provides the hydrogen production device with the electric energy corresponding to the operation at the minimum operating power.

6. The DC microgrid hydrogen production system according to claim 5, characterized in that: The system also includes an AC public power grid, and the smart energy management and control platform is also used for: When the generated power is less than the minimum operating power and the electric energy corresponding to the current SOC of the energy storage device is less than the electric energy required for the minimum operating power, the hydrogen production device is connected to the AC public power grid so that the AC public power grid provides electric energy for the hydrogen production device.

7. The DC microgrid hydrogen production system according to claim 6, characterized in that: The smart energy management and control platform is also used for: In the event of a failure of the renewable energy unit, the hydrogen production device is connected to the AC public power grid so that the AC public power grid provides electrical energy to the hydrogen production device.

8. The DC microgrid hydrogen production system according to claim 3, characterized in that: The smart energy management and control platform is also used to monitor the operating parameters of the renewable energy unit, the hydrogen production device, the load unit and the energy storage device.

9. The direct current microgrid hydrogen production system according to any one of claims 1 to 8, characterized in that: When the hydrogen production device operates at full load, the voltage of the common DC bus is greater than or equal to the minimum starting voltage of the hydrogen production device.

10. The direct current microgrid hydrogen production system according to any one of claims 1 to 8, characterized in that: The renewable energy unit includes a photovoltaic power generation unit and / or a wind power generation unit.

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