A new energy grid-connected hydrogen production system and its anti-backflow control method

Abstract

The present application discloses a new energy grid-connected hydrogen production system and its anti-backflow control method to suppress the backflow of new energy power to the power grid. The method includes: when the new energy grid-connected hydrogen production system has a backflow, obtaining the backflow duration T_cnt; if T_cnt<alpha1*T_re, then increasing the power of the hydrogen production subsystem to suppress the backflow; if alpha1*T_re<T_cnt<alpha2*T_re, then simultaneously increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem to suppress the backflow; if T_cnt≥alpha2*T_re, then reducing the power of the new energy subsystem to suppress the backflow. Wherein, T_re is the maximum allowed continuous backflow time, alpha1 and alpha2 are coefficients, and 0 <alpha1<alpha2<1。

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production, and more specifically, to a new energy grid-connected hydrogen production system and a backflow prevention control method thereof. Background Art

[0002] Hydrogen is a green and clean energy source. With the implementation of the national energy strategy, hydrogen will become a core energy source in the future. Currently, the main factor limiting the development of hydrogen energy is the cost of hydrogen production. However, with the continued decline in the cost of new energy sources such as photovoltaic and wind power, hydrogen production from new energy sources is gradually becoming commercialized.

[0003] However, new energy sources such as photovoltaics and wind power are intermittent energy sources. Their output power varies with the external environment and may be lower than the minimum allowable input power of the hydrogen production tank. The reliability and stability of the hydrogen supply cannot be guaranteed. Therefore, in actual engineering projects, it is more appropriate to adopt new energy grid-connected hydrogen production solutions.

[0004] Figure 1 This is the architecture diagram of an existing renewable energy grid-connected hydrogen production system. The system primarily relies on the renewable energy subsystem for power, supplemented by the grid. This ensures sufficient input power to the hydrogen production tanks within the hydrogen production subsystem. However, when the renewable energy subsystem's response speed (which reflects the rate of change of power) is faster than the hydrogen production subsystem's, excess renewable energy power will flow back into the grid. This excess renewable energy power backflow into the grid will consume local renewable energy grid-connected quotas. Summary of the Invention

[0005] In view of this, the present invention provides a new energy grid-connected hydrogen production system and a backflow prevention control method thereof, so as to suppress the backflow of new energy power into the power grid.

[0006] A method for preventing backflow in a new energy grid-connected hydrogen production system, comprising:

[0007] When reverse flow occurs in the new energy grid-connected hydrogen production system, obtain the reverse flow duration T_cnt;

[0008] Compare the reverse flow duration T_cnt with alpha1*T_re and alpha2*T_re; where T_re is the maximum allowed reverse flow duration, alpha1 and alpha2 are coefficients, and 0 <alpha1<alpha2<1;

[0009] If T_cnt<alpha1*T_re, the reverse flow is suppressed by increasing the power of the hydrogen production subsystem;

[0010] If alpha1*T_re<T_cnt<alpha2*T_re, then the reverse flow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem at the same time;

[0011] If T_cnt ≥ alpha2*T_re, the reverse flow is suppressed by reducing the power of the new energy subsystem.

[0012] Another anti-backflow control method for a new energy grid-connected hydrogen production system includes:

[0013] When reverse flow occurs in the new energy grid-connected hydrogen production system, obtain the reverse flow duration T_cnt;

[0014] Compare T_cnt with alpha3*T_re; T_re is the maximum allowed continuous reverse flow time, alpha3 is the coefficient, 0 <alpha3<1;

[0015] If T_cnt≤alpha3*T_re, the reverse flow is suppressed by increasing the power of the hydrogen production subsystem;

[0016] If alpha3*T_re<T_cnt, the reverse flow is suppressed by simultaneously increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem.

[0017] Another anti-backflow control method for a new energy grid-connected hydrogen production system includes:

[0018] When reverse flow occurs in the new energy grid-connected hydrogen production system, obtain the reverse flow duration T_cnt;

[0019] Compare T_cnt with alpha4*T_re; T_re is the maximum allowed continuous reverse flow time, alpha4 is the coefficient, 0 <alpha4<1;

[0020] If T_cnt≤alpha4*T_re, the reverse flow is suppressed by increasing the power of the hydrogen production subsystem;

[0021] If alpha4*T_re<T_cnt, the reverse flow is suppressed by reducing the power of the new energy subsystem.

[0022] Another anti-backflow control method for a new energy grid-connected hydrogen production system includes:

[0023] When reverse flow occurs in the new energy grid-connected hydrogen production system, obtain the reverse flow duration T_cnt;

[0024] Compare T_cnt with alpha5*T_re; T_re is the maximum allowed continuous reverse flow time, alpha5 is the coefficient, 0 <alpha5<1;

[0025] If T_cnt≤alpha5*T_re, the reverse flow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem at the same time;

[0026] If alpha5*T_re<T_cnt, the reverse flow is suppressed by reducing the power of the new energy subsystem.

[0027] Optionally, the method of simultaneously increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem to suppress the backflow includes:

[0028] When T_cnt≤alpha6*T_re, the reverse flow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem, and the power reduction value of the new energy subsystem is less than the power increase value of the hydrogen production subsystem; where alpha6 is a coefficient, 0 <alpha6<1;

[0029] When T_cnt>alpha6*T_re, the reverse flow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem at the same time, and the power reduction value of the new energy subsystem is greater than or equal to the power increase value of the hydrogen production subsystem.

[0030] Optionally, when increasing the power of the hydrogen production subsystem and / or reducing the power of the new energy subsystem, the power adjustment values of the corresponding subsystems are set with the goal of reducing the reverse flow power P_re to the reverse flow power limit P_re_limit.

[0031] Optionally, after obtaining the counterflow duration T_cnt, the method further includes:

[0032] When the reverse flow time T_cnt exceeds the threshold and the reverse flow power P_re exceeds a1*P_re_limit, the reverse flow time T_cnt is modified to a larger value; where a1 is a coefficient, 1 <a1。

[0033] Optionally, when the reverse flow duration T_cnt exceeds a threshold and the reverse flow power P_re exceeds a1*P_re_limit, modifying the reverse flow duration T_cnt to a larger value includes:

[0034] When a1*P_re_limit<P_re<a2*P_re_limit, modify T_cnt to the current value of T_cnt plus (P_re-P_re_limit) / P_rate_pv;

[0035] When P_re ≥ a2 * P_re_limit, modify T_cnt to the current value of T_cnt plus (a2 * P_re_limit - P_re_limit) / P_rate_pv;

[0036] Among them, a1 and a2 are coefficients, 1 < a1 < a2, and P_rate_pv is the power regulation rate of the new energy subsystem.

[0037] Optionally, before determining whether the reverse power P_re exceeds a1 * P_re_limit, it further includes: correcting the reverse power Pre according to the reverse power change rate P_re_add_pre and the system communication delay time T_del, and the corrected reverse power P_re is the current value of P_re plus P_re_add_pre * T_del.

[0038] Optionally, the new energy grid-connected hydrogen production system further includes an energy storage subsystem; at this time, when the new energy grid-connected hydrogen production system anti-reverse control method reduces the power of the new energy subsystem, it simultaneously increases the charging power of the energy storage subsystem.

[0039] A new energy grid-connected hydrogen production system includes: a new energy subsystem, a hydrogen production subsystem, an anti-reverse module, and an energy controller;

[0040] The new energy subsystem and the hydrogen production subsystem are connected to the grid through a common AC bus; the anti-reverse module is connected between the common AC bus and the grid;

[0041] The energy controller is used to obtain the reverse current duration T_cnt through the anti-reverse module when reverse current occurs in the new energy grid-connected hydrogen production system; compare the reverse current duration T_cnt with alpha1 * T_re and alpha2 * T_re; where T_re is the maximum allowable continuous reverse current time, alpha1 and alpha2 are coefficients, and 0 < alpha1 < alpha2 < 1; if T_cnt < alpha1 * T_re, the method of increasing the power of the hydrogen production subsystem is adopted to suppress the reverse current; if alpha1 * T_re < T_cnt < alpha2 * T_re, the methods of increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem are adopted simultaneously to suppress the reverse current; if T_cnt ≥ alpha2 * T_re, the method of reducing the power of the new energy subsystem is adopted to suppress the reverse current.

[0042] Another new energy grid-connected hydrogen production system includes: a new energy subsystem, a hydrogen production subsystem, an anti-reverse module, and an energy controller;

[0043] The new energy subsystem and the hydrogen production subsystem are connected to the power grid through a common AC bus; the anti-counterflow module is connected between the common AC bus and the power grid;

[0044] The energy controller is configured to, when a counterflow occurs in the new energy grid-connected hydrogen production system, obtain the counterflow duration T_cnt; compare the magnitude of T_cnt with alpha3*T_re; where T_re is the maximum allowable continuous counterflow time and alpha3 is a coefficient, 0 < alpha3 < 1; if T_cnt ≤ alpha3*T_re, then increase the power of the hydrogen production subsystem to suppress the counterflow; if alpha3*T_re < T_cnt, then simultaneously increase the power of the hydrogen production subsystem and decrease the power of the new energy subsystem to suppress the counterflow.

[0045] Another new energy grid-connected hydrogen production system includes: a new energy subsystem, a hydrogen production subsystem, an anti-counterflow module, and an energy controller;

[0046] The new energy subsystem and the hydrogen production subsystem are connected to the power grid through a common AC bus; the anti-counterflow module is connected between the common AC bus and the power grid;

[0047] The energy controller is configured to, when a counterflow occurs in the new energy grid-connected hydrogen production system, obtain the counterflow duration T_cnt; compare the magnitude of T_cnt with alpha4*T_re; where T_re is the maximum allowable continuous counterflow time and alpha4 is a coefficient, 0 < alpha4 < 1; if T_cnt ≤ alpha4*T_re, then increase the power of the hydrogen production subsystem to suppress the counterflow; if alpha4*T_re < T_cnt, then decrease the power of the new energy subsystem to suppress the counterflow.

[0048] Another new energy grid-connected hydrogen production system includes: a new energy subsystem, a hydrogen production subsystem, an anti-counterflow module, and an energy controller;

[0049] The new energy subsystem and the hydrogen production subsystem are connected to the power grid through a common AC bus; the anti-counterflow module is connected between the common AC bus and the power grid;

[0050] The energy controller is used to obtain the reverse flow duration T_cnt when reverse flow occurs in the new energy grid-connected hydrogen production system; compare the size of T_cnt with alpha5*T_re; where T_re is the maximum allowable continuous reverse flow time, and alpha5 is a coefficient, 0 < alpha5 < 1; if T_cnt ≤ alpha5*T_re, then increase the power of the hydrogen production subsystem and decrease the power of the new energy subsystem at the same time to suppress the reverse flow; if alpha5*T_re < T_cnt, then adopt the method of reducing the power of the new energy subsystem to suppress the reverse flow.

[0051] Optionally, any of the above-mentioned new energy grid-connected hydrogen production systems further includes an energy storage subsystem; at this time, when the energy controller reduces the power of the new energy subsystem, it increases the charging power of the energy storage subsystem at the same time.

[0052] As can be seen from the above technical solutions, when the new energy power reverses to the power grid in the present invention, according to the difference in the response speeds of the new energy subsystem and the hydrogen production subsystem, the power of the new energy subsystem and the hydrogen production subsystem is optimized and scheduled. Specifically: when the reverse flow duration is short, the method of increasing the power of the hydrogen production subsystem is preferentially used to suppress the reverse flow, and if there is no effect, the method of reducing the power of the new energy subsystem is introduced to suppress the reverse flow. In this way, the present invention not only suppresses the reverse flow of new energy power to the power grid, but also tries its best to reduce the waste of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0054] Figure 1 It is a schematic diagram of the architecture of a new energy grid-connected hydrogen production system disclosed in the prior art;

[0055] Figure 2 It is a schematic diagram of the architecture of a new energy grid-connected hydrogen production system disclosed in an embodiment of the present invention;

[0056] Figure 3 It is a flowchart of a reverse flow prevention control method for a new energy grid-connected hydrogen production system disclosed in an embodiment of the present invention;

[0057] Figure 4 It is a flowchart of another reverse flow prevention control method for a new energy grid-connected hydrogen production system disclosed in an embodiment of the present invention;

[0058] Figure 5This is a flow chart of another backflow prevention control method for a new energy grid-connected hydrogen production system disclosed in an embodiment of the present invention;

[0059] Figure 6 This is a flow chart of another backflow prevention control method for a new energy grid-connected hydrogen production system disclosed in an embodiment of the present invention;

[0060] Figure 7 This is a flow chart of another anti-backflow control method for a new energy grid-connected hydrogen production system disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0062] The embodiment of the present invention first adds an anti-backflow module based on the existing new energy grid-connected hydrogen production system, such as Figure 2 As shown, the anti-backflow module is connected between the public AC bus of the new energy grid-connected hydrogen production system and the power grid, and is used to detect parameters such as the current backflow power P_re and the continuous backflow time T_cnt, and send them to the energy controller ( Figure 2 (not shown) so that the energy controller can optimize the power scheduling of the new energy subsystem and the hydrogen production subsystem according to the difference in response speed between the new energy subsystem and the hydrogen production subsystem to ensure sufficient input power to the hydrogen production tank and suppress the backflow of new energy power to the power grid.

[0063] The above functions can be realized by Figure 3 The anti-backflow control method of the new energy grid-connected hydrogen production system shown in the figure includes:

[0064] Step S01: When a reverse flow occurs in the new energy grid-connected hydrogen production system, the reverse flow duration T_cnt is obtained, and then step S02 is entered.

[0065] Specifically, assuming that the reverse flow power limit is P_re_limit, reverse flow occurs in the new energy grid-connected hydrogen production system, which means that the reverse flow power P_re exceeds the reverse flow power limit P_re_limit.

[0066] Step S02: Compare the reverse flow duration T_cnt with alpha1*T_re and alpha2*T_re; if T_cnt≤alpha1*T_re, proceed to step S03; if alpha1*T_re<T_cnt<alpha2*T_re, proceed to step S04; if T_cnt≥alpha2*T_re, proceed to step S05. Where T_re is the maximum allowed reverse flow duration, alpha1 and alpha2 are coefficients, and 0 <alpha1<alpha2<1。

[0067] Step S03: suppressing the backflow by increasing the power of the hydrogen production subsystem.

[0068] Step S04: The backflow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem at the same time.

[0069] Step S05: suppressing the reverse flow by reducing the power of the new energy subsystem.

[0070] Specifically, when the response speed of the new energy subsystem is faster than that of the hydrogen production subsystem, excess new energy power will flow back into the grid. Increasing the power of the hydrogen production subsystem or reducing the power of the new energy subsystem can suppress this backflow. However, suppressing this backflow by reducing the power of the new energy subsystem will result in a waste of new energy. While suppressing this backflow by increasing the power of the hydrogen production subsystem avoids the waste of new energy, its response speed is slower than reducing the power of the new energy subsystem. Based on this, in an embodiment of the present invention, when the reverse flow duration T_cnt is short, the reverse flow is preferably suppressed by increasing the power of the hydrogen production subsystem. If there is no effect, the reverse flow is suppressed by reducing the power of the new energy subsystem, thereby trying to avoid suppressing the reverse flow at the expense of the utilization rate of new energy. The specific scheme is: when the reverse flow duration T_cnt is short (i.e., T_cnt≤alpha1*T_re), the reverse flow is first suppressed by simply increasing the power of the hydrogen production subsystem; if the reverse flow duration T_cnt continues to increase and rises by one step (i.e., alpha1*T_re<T_cnt<alpha2*T_re), the reverse flow is suppressed by simultaneously increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem; if the reverse flow duration T_cnt continues to increase and rises by one step again (i.e., T_cnt≥alpha2*T_re), the reverse flow is suppressed by simply reducing the power of the new energy subsystem.

[0071] Among them, T_re is the maximum allowable continuous reverse flow time, alpha1 and alpha2 are coefficients, 0 < alpha1 < alpha2 < 1, and the specific values of alpha1 and alpha2 can be reasonably selected according to the response speed of the new energy subsystem / hydrogen production subsystem and the actual setting value of the maximum allowable continuous reverse flow time T_re.

[0072] Suppressing reverse flow means restricting the reverse flow power P_re to not exceed the reverse flow power limit P_re_limit. The embodiment of the present invention recommends that the best suppression depth for reverse flow is exactly no reverse flow (that is, it is recommended that when increasing the power of the hydrogen production subsystem and / or reducing the power of the new energy subsystem, the power adjustment value of the corresponding subsystem is set with the goal of reducing the reverse flow power P_re to the reverse flow power limit P_re_limit). That is to say: when T_cnt ≤ alpha1 * T_re, the best power increase value P_add_hd of the hydrogen production subsystem = P_re - P_re_limit; when alpha1 * T_re < T_cnt < alpha2 * T_re, the best power reduction value P_red_pv of the new energy subsystem = (P_re - P_re_limit) * b1, the best power increase value P_add_hd of the hydrogen production subsystem = (P_re - P_re_limit) * b2, b1 and b2 are coefficients, b1 + b2 = 1; when T_cnt ≥ alpha2 * T_re, the best power reduction value P_red_pv of the new energy subsystem = P_re - P_re_limit.

[0073] From the above description of Figure 3 the technical solution shown, in the embodiment of the present invention, when new energy power flows reversely into the power grid, according to the difference in the response speed between the new energy subsystem and the hydrogen production subsystem, the power of the new energy subsystem and the hydrogen production subsystem is optimized and scheduled. Specifically: when the reverse flow duration T_cnt is short, the method of increasing the power of the hydrogen production subsystem is preferentially used to suppress reverse flow, and if there is no effect, the method of reducing the power of the new energy subsystem is introduced to suppress reverse flow. In this way, the embodiment of the present invention not only suppresses the reverse flow of new energy power into the power grid, but also tries its best to reduce the waste of new energy. The embodiment of the present invention is particularly applicable to application scenarios where the power grid does not have enough accommodation space.

[0074] Figure 3 In the anti-reverse flow process of the technical solution shown, it can be divided into at most three stages. In addition, it can also be reduced to at most two stages, for example Figure 4 、 Figure 5 or Figure 6 shown.

[0075] Figure 4 The anti-reverse flow control method of the new energy grid-connected hydrogen production system shown includes:

[0076] Step S11: When a reverse flow occurs in the new energy grid-connected hydrogen production system, the reverse flow duration T_cnt is obtained, and then step S12 is entered.

[0077] Step S12: Compare T_cnt with alpha3*T_re; if T_cnt≤alpha3*T_re, proceed to step S13; if alpha3*T_re<T_cnt, proceed to step S04. Wherein, T_re is the maximum allowed continuous reverse flow time, alpha3 is the coefficient, 0 <alpha3<1。

[0078] Step S13: suppressing the backflow by increasing the power of the hydrogen production subsystem.

[0079] Step S14: The backflow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem at the same time.

[0080] Figure 5 The anti-backflow control method of the new energy grid-connected hydrogen production system shown includes:

[0081] Step S21: When a reverse flow occurs in the new energy grid-connected hydrogen production system, the reverse flow duration T_cnt is obtained, and then step S22 is entered.

[0082] Step S22: Compare T_cnt with alpha4*T_re; if T_cnt≤alpha4*T_re, proceed to step S23; if alpha4*T_re<T_cnt, proceed to step S24. Wherein, T_re is the maximum allowed continuous reverse flow time, alpha4 is the coefficient, 0 <alpha4<1。

[0083] Step S23: suppressing the backflow by increasing the power of the hydrogen production subsystem.

[0084] Step S24: suppressing the reverse flow by reducing the power of the new energy subsystem.

[0085] Figure 6 The anti-backflow control method of the new energy grid-connected hydrogen production system shown includes:

[0086] Step S31: When a reverse flow occurs in the new energy grid-connected hydrogen production system, the reverse flow duration T_cnt is obtained, and then step S32 is entered.

[0087] Step S32: Compare T_cnt with alpha5*T_re; if T_cnt≤alpha5*T_re, proceed to step S33; if alpha5*T_re<T_cnt, proceed to step S34. Wherein, T_re is the maximum allowed continuous reverse flow time, alpha5 is the coefficient, 0 <alpha5<1。

[0088] Step S33: The backflow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem at the same time.

[0089] Step S34: suppressing the reverse flow by reducing the power of the new energy subsystem.

[0090] Optional, in Figure 3 、 Figure 4 or Figure 6 In the anti-backflow control method for the grid-connected hydrogen production system of new energy shown in the figure, the stage of suppressing the backflow by simultaneously increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem can be further divided into the following two stages: 1) When T_cnt≤alpha6*T_re, the backflow is suppressed by simultaneously increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem, and the power reduction value of the new energy subsystem is less than the power increase value of the hydrogen production subsystem; 2) When T_cnt>alpha6*T_re, the backflow is suppressed by simultaneously increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem, and the power reduction value of the new energy subsystem is greater than or equal to the power increase value of the hydrogen production subsystem; wherein, alpha6 is a coefficient, 0 <alpha6<1。

[0091] Optionally, in the above-mentioned stage 1), an embodiment of the present invention recommends that the optimal power reduction value of the new energy subsystem P_red_pv = (P_re-P_re_limit)*b1, and the optimal power increase value of the hydrogen production subsystem P_add_hd = (P_re-P_re_limit)*b2, b1 and b2 are coefficients, b1+b2=1, b1≤b2; in the above-mentioned stage 2), an embodiment of the present invention recommends that the optimal power reduction value of the new energy subsystem P_red_pv = (P_re-P_re_limit)*b1, and the optimal power increase value of the hydrogen production subsystem P_add_hd = (P_re-P_re_limit)*b2, b1 and b2 are coefficients, b1+b2=1, b1>b2.

[0092] In the actual application process of any of the above - disclosed anti - backflow control methods for new - energy grid - connected hydrogen - production systems, considering factors such as detection delay, communication delay, and response delay, to avoid the situation where the continuous backflow time T_cnt accidentally exceeds the allowed maximum continuous backflow time T_re, the embodiments of the present invention recommend that when the continuous backflow time T_cnt is close to the allowed maximum continuous backflow time T_re and the backflow power P_re is relatively large (this state is measured by the continuous backflow time T_cnt exceeding the threshold and the backflow power P_re exceeding a1*P_re_limit), the continuous backflow time T_cnt is modified to a larger value, so as to enter a stage with a faster response speed for suppressing backflow in advance.

[0093] Among them, when the continuous backflow time T_cnt exceeds the threshold and the backflow power P_re exceeds a1*P_re_limit, the continuous backflow time T_cnt is modified to a larger value. For example: when the continuous backflow time T_cnt exceeds the threshold and a1*P_re_limit < P_re < a2*P_re_limit, T_cnt is modified to the current value of T_cnt plus (P_re - P_re_limit) / P_rate_pv; when the continuous backflow time T_cnt exceeds the threshold and P_re ≥ a2*P_re_limit, T_cnt is modified to the current value of T_cnt plus (a2*P_re_limit - P_re_limit) / P_rate_pv; a1 and a2 are coefficients, 1 < a1 < a2, and P_rate_pv is the power regulation rate of the new - energy subsystem, with the unit of kW / S.

[0094] Optionally, considering the influence of communication delay factors, before judging whether the backflow power P_re exceeds a1*P_re_limit, P_re is also corrected. For example, by collecting multiple backflow powers and using methods such as linear fitting and neural networks to predict the change trend of the backflow power, the backflow power change rate P_re_add_pre is obtained, and then P_re is modified to the current value of P_re plus P_re_add_pre*T_del, where T_del is the pre - calibrated system communication delay time. For example, based on Figure 3 make modifications, and the corresponding technical solution is as Figure 7 shown, including:

[0095] Step S41: When backflow occurs in the new - energy grid - connected hydrogen - production system, obtain the backflow duration T_cnt and the backflow power P_re, and then enter step S42.

[0096] Step S42: Modify the reverse power P_re to the current value of P_re plus P_re_add_pre*T_del; where T_del is the pre-calibrated system communication delay time and P_re_add_pre is the reverse power change rate. The modified reverse power P_re value is then used in the calculation of step S43.

[0097] Step S43: When the reverse flow duration T_cnt exceeds the threshold and the reverse flow power P_re exceeds a1*P_re_limit, the reverse flow duration T_cnt is modified to a larger value. The modified reverse flow power P_re and reverse flow duration T_cnt are then used in the calculations of steps S44 to S47.

[0098] Step S44: Compare the reverse flow duration T_cnt with alpha1*T_re and alpha2*T_re; if T_cnt≤alpha1*T_re, proceed to step S45; if alpha1*T_re<T_cnt<alpha2*T_re, proceed to step S46; if T_cnt≥alpha2*T_re, proceed to step S47. Where T_re is the maximum allowed reverse flow duration, alpha1 and alpha2 are coefficients, and 0 <alpha1<alpha2<1。

[0099] Step S45: suppressing the backflow by increasing the power of the hydrogen production subsystem.

[0100] Step S46: The reverse flow is suppressed by increasing the power of the hydrogen production subsystem and reducing the power of the new energy subsystem at the same time.

[0101] Step S47: suppressing the reverse flow by reducing the power of the new energy subsystem.

[0102] Optionally, an energy storage subsystem can be incorporated into any of the aforementioned grid-connected hydrogen production systems. In this case, the anti-backflow control method for a grid-connected hydrogen production system reduces the power of the new energy subsystem while simultaneously increasing the charging power of the energy storage subsystem. This reduces the power reduction of the new energy subsystem and reduces the waste of new energy compared to any of the aforementioned grid-connected hydrogen production systems.

[0103] Corresponding to the above method embodiment, the embodiment of the present invention further discloses a new energy grid-connected hydrogen production system, comprising: a new energy subsystem, a hydrogen production subsystem, an anti-backflow module and an energy controller;

[0104] The new energy subsystem and the hydrogen production subsystem are connected to the power grid through a public AC bus; the anti-backflow module is connected between the public AC bus and the power grid;

[0105] The energy controller is used to obtain the reverse current duration T_cnt through the anti-reverse current module when reverse current occurs in the new energy grid-connected hydrogen production system; compare the size of the reverse current duration T_cnt with alpha1*T_re and alpha2*T_re; where T_re is the maximum allowable continuous reverse current time, alpha1 and alpha2 are coefficients, and 0 < alpha1 < alpha2 < 1; if T_cnt < alpha1*T_re, the power of the hydrogen production subsystem is increased to suppress the reverse current; if alpha1*T_re < T_cnt < alpha2*T_re, both the power of the hydrogen production subsystem is increased and the power of the new energy subsystem is decreased to suppress the reverse current; if T_cnt >= alpha2*T_re, the power of the new energy subsystem is decreased to suppress the reverse current.

[0106] Another new energy grid-connected hydrogen production system includes: a new energy subsystem, a hydrogen production subsystem, an anti-reverse current module, and an energy controller;

[0107] The new energy subsystem and the hydrogen production subsystem are connected to the grid through a common AC bus; the anti-reverse current module is connected between the common AC bus and the grid;

[0108] The energy controller is used to obtain the reverse current duration T_cnt when reverse current occurs in the new energy grid-connected hydrogen production system; compare the size of T_cnt with alpha3*T_re; where T_re is the maximum allowable continuous reverse current time, alpha3 is a coefficient, 0 < alpha3 < 1; if T_cnt <= alpha3*T_re, the power of the hydrogen production subsystem is increased to suppress the reverse current; if alpha3*T_re < T_cnt, both the power of the hydrogen production subsystem is increased and the power of the new energy subsystem is decreased to suppress the reverse current.

[0109] Another new energy grid-connected hydrogen production system includes: a new energy subsystem, a hydrogen production subsystem, an anti-reverse current module, and an energy controller;

[0110] The new energy subsystem and the hydrogen production subsystem are connected to the grid through a common AC bus; the anti-reverse current module is connected between the common AC bus and the grid;

[0111] The energy controller is used to obtain the reverse flow duration T_cnt when a reverse flow occurs in the new energy grid-connected hydrogen production system; compare the magnitude of T_cnt with alpha4*T_re; where T_re is the maximum allowable continuous reverse flow time, and alpha4 is a coefficient, 0 < alpha4 < 1; if T_cnt ≤ alpha4*T_re, the power of the hydrogen production subsystem is increased to suppress the reverse flow; if alpha4*T_re < T_cnt, the power of the new energy subsystem is reduced to suppress the reverse flow.

[0112] Another new energy grid-connected hydrogen production system includes: a new energy subsystem, a hydrogen production subsystem, an anti-reverse flow module, and an energy controller;

[0113] The new energy subsystem and the hydrogen production subsystem are connected to the power grid through a common AC bus; the anti-reverse flow module is connected between the common AC bus and the power grid;

[0114] The energy controller is used to obtain the reverse flow duration T_cnt when a reverse flow occurs in the new energy grid-connected hydrogen production system; compare the magnitude of T_cnt with alpha5*T_re; where T_re is the maximum allowable continuous reverse flow time, and alpha5 is a coefficient, 0 < alpha5 < 1; if T_cnt ≤ alpha5*T_re, the power of the hydrogen production subsystem is increased and the power of the new energy subsystem is reduced simultaneously to suppress the reverse flow; if alpha5*T_re < T_cnt, the power of the new energy subsystem is reduced to suppress the reverse flow.

[0115] Optionally, in any of the new energy grid-connected hydrogen production systems disclosed above, when increasing the power of the hydrogen production subsystem and / or reducing the power of the new energy subsystem, the power adjustment value of the corresponding subsystem is set with the goal of reducing the reverse flow power P_re to the reverse flow power limit P_re_limit.

[0116] Optionally, in any of the new energy grid-connected hydrogen production systems disclosed above, after obtaining the reverse flow duration T_cnt, after obtaining the reverse flow duration T_cnt, the energy controller is further used to modify the continuous reverse flow duration T_cnt to a larger value when the continuous reverse flow duration T_cnt exceeds the threshold and the reverse flow power P_re exceeds a1*P_re_limit; where a1 is a coefficient, 1 < a1.

[0117] Optionally, when the continuous reverse flow duration T_cnt exceeds the threshold and the reverse flow power P_re exceeds a1*P_re_limit, modifying the continuous reverse flow duration T_cnt to a larger value specifically includes:

[0118] When a1 * P_re_limit < P_re < a2 * P_re_limit, modify T_cnt to the current value of T_cnt plus (P_re - P_re_limit) / P_rate_pv;

[0119] When P_re ≥ a2 * P_re_limit, modify T_cnt to the current value of T_cnt plus (a2 * P_re_limit - P_re_limit) / P_rate_pv;

[0120] Where a1 and a2 are coefficients, 1 < a1 < a2, and P_rate_pv is the power regulation rate of the new energy subsystem.

[0121] Optionally, before determining whether the reverse power P_re exceeds a1 * P_re_limit, the energy controller is further configured to modify the reverse power P_re to the current value of P_re plus P_re_add_pre * T_del; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse power change rate.

[0122] Optionally, in any of the new energy grid-connected hydrogen production systems disclosed above, the new energy grid-connected hydrogen production system further includes an energy storage subsystem; at this time, when the energy controller reduces the power of the new energy subsystem, it simultaneously increases the charging power of the energy storage subsystem.

[0123] Optionally, in any of the new energy grid-connected hydrogen production systems disclosed above, the anti-reverse power flow module includes an electricity meter and a control module, or the anti-reverse power flow module includes a current flow direction sensor and a control module, which is not limited.

[0124] Optionally, in any of the new energy grid-connected hydrogen production systems disclosed above, the new energy subsystem may be, for example, a photovoltaic subsystem and / or a wind power subsystem.

[0125] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0126] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preventing backflow in a new energy grid-connected hydrogen production system, characterized in that: Comprising: When reverse current occurs in the new energy grid-connected hydrogen production system, obtain the reverse current duration T_cnt and the reverse current power P_re; Modify the reverse current power P_re to the current value of P_re plus P_re_add_pre * T_del to obtain the corrected reverse current power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse current power change rate; When the reverse current duration T_cnt exceeds the threshold and the corrected reverse current power P'_re exceeds a1 * P_re_limit, modify the reverse current duration T_cnt to a larger value T'_cnt; where a1 is a coefficient and 1 < a1; Compare the latest reverse current duration T'_cnt with alpha1 * T_re and alpha2 * T_re; where T_re is the maximum allowable continuous reverse current time, alpha1 and alpha2 are coefficients, and 0 < alpha1 < alpha2 < 1; the values of alpha1 and alpha2 are selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowable continuous reverse current time T_re; If T'_cnt < alpha1 * T_re, suppress the reverse current by increasing the power of the hydrogen production subsystem; If alpha1 * T_re < T'_cnt < alpha2 * T_re, suppress the reverse current by simultaneously increasing the power of the hydrogen production subsystem and decreasing the power of the new energy subsystem; If T'_cnt ≥ alpha2 * T_re, suppress the reverse current by decreasing the power of the new energy subsystem.

2. A method for preventing backflow in a new energy grid-connected hydrogen production system, characterized in that: Comprising: When reverse current occurs in the new energy grid-connected hydrogen production system, obtain the reverse current duration T_cnt and the reverse current power P_re; Modify the reverse current power P_re to the current value of P_re plus P_re_add_pre * T_del to obtain the corrected reverse current power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse current power change rate; When the reverse current duration T_cnt exceeds the threshold and the corrected reverse current power P'_re exceeds a1 * P_re_limit, modify the reverse current duration T_cnt to a larger value T'_cnt; where a1 is a coefficient and 1 < a1; Compare the latest T'_cnt with alpha3 * T_re; where T_re is the maximum allowable continuous reverse current time, alpha3 is a coefficient, 0 < alpha3 < 1; the value of alpha3 is selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowable continuous reverse current time T_re; If T'_cnt ≤ alpha3 * T_re, suppress the reverse current by increasing the power of the hydrogen production subsystem; If alpha3 * T_re < T'_cnt, then both increase the power of the hydrogen production subsystem and decrease the power of the new energy subsystem to suppress reverse current.

3. A method for preventing backflow in a new energy grid-connected hydrogen production system, characterized in that: Including: When reverse current occurs in the new energy grid-connected hydrogen production system, obtain the reverse current duration T_cnt and the reverse current power P_re; Modify the reverse current power P_re to the current value of P_re plus P_re_add_pre * T_del to obtain the corrected reverse current power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse current power change rate; When the reverse current duration T_cnt exceeds the threshold and the corrected reverse current power P'_re exceeds a1 * P_re_limit, modify the reverse current duration T_cnt to a larger value T'_cnt; where a1 is a coefficient, 1 < a1; Compare the latest reverse current duration T'_cnt with alpha4 * T_re; where T_re is the maximum allowable continuous reverse current time, alpha4 is a coefficient, 0 < alpha4 < 1; the value of alpha4 is selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowable continuous reverse current time T_re; If T'_cnt ≤ alpha4 * T_re, then increase the power of the hydrogen production subsystem to suppress reverse current; If alpha4 * T_re < T'_cnt, then decrease the power of the new energy subsystem to suppress reverse current.

4. A method for preventing backflow in a new energy grid-connected hydrogen production system, characterized in that: Including: When reverse current occurs in the new energy grid-connected hydrogen production system, obtain the reverse current duration T_cnt and the reverse current power P_re; Modify the reverse current power P_re to the current value of P_re plus P_re_add_pre * T_del to obtain the corrected reverse current power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse current power change rate; When the reverse current duration T_cnt exceeds the threshold and the corrected reverse current power P'_re exceeds a1 * P_re_limit, modify the reverse current duration T_cnt to a larger value T'_cnt; where a1 is a coefficient, 1 < a1; Compare the latest reverse current duration T'_cnt with alpha5 * T_re; where T_re is the maximum allowable continuous reverse current time, alpha5 is a coefficient, 0 < alpha5 < 1; the value of alpha5 is selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowable continuous reverse current time T_re; If T'_cnt ≤ alpha5 * T_re, then both increase the power of the hydrogen production subsystem and decrease the power of the new energy subsystem to suppress reverse current; If alpha5 * T_re < T'_cnt, then decrease the power of the new energy subsystem to suppress reverse current.

5. The anti-backflow control method for a new energy grid-connected hydrogen production system according to any one of claims 1 to 2 or 4, characterized in that: The method of suppressing reverse current by simultaneously increasing the power of the hydrogen production subsystem and decreasing the power of the new energy subsystem includes: When T’_cnt ≤ alpha6 * T_re, suppress reverse current by simultaneously increasing the power of the hydrogen production subsystem and decreasing the power of the new energy subsystem, and the decrease value of the power of the new energy subsystem is less than the increase value of the power of the hydrogen production subsystem; where alpha6 is a coefficient, 0 < alpha6 < 1; When T’_cnt > alpha6 * T_re, suppress reverse current by simultaneously increasing the power of the hydrogen production subsystem and decreasing the power of the new energy subsystem, and the decrease value of the power of the new energy subsystem is greater than or equal to the increase value of the power of the hydrogen production subsystem.

6. The anti-backflow control method for a new energy grid-connected hydrogen production system according to any one of claims 1 to 3, characterized in that: When suppressing reverse current, when increasing the power of the hydrogen production subsystem, set the power adjustment value of the corresponding subsystem with the goal of reducing the reverse current power P_re to the reverse current power limit P_re_limit.

7. The anti-backflow control method for a new energy grid-connected hydrogen production system according to any one of claims 1, 3, and 4, characterized in that: When suppressing reverse current, when decreasing the power of the new energy subsystem, set the power adjustment value of the corresponding subsystem with the goal of reducing the reverse current power P_re to the reverse current power limit P_re_limit.

8. The anti-backflow control method for a new energy grid-connected hydrogen production system according to any one of claims 1, 2, and 4, characterized in that: When suppressing reverse current, when increasing the power of the hydrogen production subsystem and decreasing the power of the new energy subsystem, set the power adjustment value of the corresponding subsystem with the goal of reducing the reverse current power P_re to the reverse current power limit P_re_limit.

9. The anti-backflow control method for a new energy grid-connected hydrogen production system according to claim 1, characterized in that: The method of modifying the continuous reverse current time T_cnt to a larger value T’_cnt when the reverse current duration T_cnt exceeds the threshold and the corrected reverse current power P’_re exceeds a1 * P_re_limit includes: When a1 * P_re_limit < P’_re < a2 * P_re_limit, modify T_cnt to the current value of T_cnt plus (P_re - P_re_limit) / P_rate_pv; When P’_re ≥ a2 * P_re_limit, modify T_cnt to the current value of T_cnt plus (a2 * P_re_limit - P_re_limit) / P_rate_pv; Where a2 is a coefficient, a1 < a2, and P_rate_pv is the power adjustment rate of the new energy subsystem.

10. The anti-backflow control method for a new energy grid-connected hydrogen production system according to any one of claims 1 to 4, characterized in that: The new energy grid-connected hydrogen production system further includes an energy storage subsystem; at this time, when the method for preventing reverse current control of the new energy grid-connected hydrogen production system decreases the power of the new energy subsystem, it simultaneously increases the charging power of the energy storage subsystem.

11. A new energy grid-connected hydrogen production system, characterized in that: It includes: A new energy subsystem, a hydrogen production subsystem, a reverse current prevention module, and an energy controller; The new energy subsystem and the hydrogen production subsystem are connected to the grid through a common AC bus; the reverse current prevention module is connected between the common AC bus and the grid; The energy controller is used to obtain the reverse current duration T_cnt and the reverse current power P_re through the anti-reverse current module when reverse current occurs in the new energy grid-connected hydrogen production system; modify the reverse current power P_re to the current value of P_re plus P_re_add_pre*T_del to obtain the corrected reverse current power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse current power change rate; when the reverse current duration T_cnt exceeds the threshold and the corrected reverse current power P'_re exceeds a1*P_re_limit, modify the reverse current duration T_cnt to a larger value T'_cnt; where a1 is a coefficient and 1 < a1; compare the latest reverse current duration T'_cnt with alpha1*T_re and alpha2*T_re; where T_re is the maximum allowed continuous reverse current time, and alpha1 and alpha2 are coefficients, and 0 < alpha1 < alpha2 < 1; the values of alpha1 and alpha2 are selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowed continuous reverse current time T_re; if T'_cnt < alpha1*T_re, the power of the hydrogen production subsystem is increased to suppress the reverse current; if alpha1*T_re < T'_cnt < alpha2*T_re, both the power of the hydrogen production subsystem is increased and the power of the new energy subsystem is decreased to suppress the reverse current; if T'_cnt >= alpha2*T_re, the power of the new energy subsystem is decreased to suppress the reverse current.

12. A new energy grid-connected hydrogen production system, characterized in that: Including: A new energy subsystem, a hydrogen production subsystem, an anti-reverse current module and an energy controller; The new energy subsystem and the hydrogen production subsystem are connected to the grid through a common AC bus; the anti-reverse current module is connected between the common AC bus and the grid; The energy controller is used to obtain the reverse flow duration T_cnt and the reverse flow power P_re when reverse flow occurs in the new energy grid-connected hydrogen production system; modify the reverse flow power P_re to the current value of P_re plus P_re_add_pre * T_del to obtain the corrected reverse flow power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse flow power change rate; when the reverse flow duration T_cnt exceeds the threshold and the corrected reverse flow power P'_re exceeds a1 * P_re_limit, modify the reverse flow duration T_cnt to a larger value T'_cnt; where a1 is a coefficient, 1 < a1; compare the latest T'_cnt with alpha3 * T_re; where T_re is the maximum allowable continuous reverse flow time, and alpha3 is a coefficient, 0 < alpha3 < 1; the value of alpha3 is selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowable continuous reverse flow time T_re; if T'_cnt ≤ alpha3 * T_re, suppress the reverse flow by increasing the power of the hydrogen production subsystem; if alpha3 * T_re < T'_cnt, suppress the reverse flow by simultaneously increasing the power of the hydrogen production subsystem and decreasing the power of the new energy subsystem.

13. A new energy grid-connected hydrogen production system, characterized in that: Including: A new energy subsystem, a hydrogen production subsystem, an anti-reverse flow module, and an energy controller; The new energy subsystem and the hydrogen production subsystem are connected to the power grid through a common AC bus; the anti-reverse flow module is connected between the common AC bus and the power grid; The energy controller is used to obtain the reverse flow duration T_cnt and the reverse flow power P_re when reverse flow occurs in the new energy grid-connected hydrogen production system; modify the reverse flow power P_re to the current value of P_re plus P_re_add_pre * T_del to obtain the corrected reverse flow power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the reverse flow power change rate; when the reverse flow duration T_cnt exceeds the threshold and the corrected reverse flow power P'_re exceeds a1 * P_re_limit, modify the continuous reverse flow time T_cnt to a larger value T'_cnt; where a1 is a coefficient, 1 < a1; compare the latest T'_cnt with alpha4 * T_re; where T_re is the maximum allowable continuous reverse flow time, and alpha4 is a coefficient, 0 < alpha4 < 1; the value of alpha4 is selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowable continuous reverse flow time T_re; if T'_cnt ≤ alpha4 * T_re, suppress the reverse flow by increasing the power of the hydrogen production subsystem; if alpha4 * T_re < T'_cnt, suppress the reverse flow by reducing the power of the new energy subsystem.

14. A new energy grid-connected hydrogen production system, characterized in that: Including: New energy subsystem, hydrogen production subsystem, anti-counterflow module and energy controller; The new energy subsystem and the hydrogen production subsystem are connected to the power grid through a common AC bus; the anti-counterflow module is connected between the common AC bus and the power grid; The energy controller is used to obtain the counterflow duration T_cnt and the counterflow power P_re when a counterflow occurs in the new energy grid-connected hydrogen production system; modify the counterflow power P_re to the current value of P_re plus P_re_add_pre*T_del to obtain the corrected counterflow power P'_re; where T_del is the pre-calibrated system communication delay time, and P_re_add_pre is the counterflow power change rate; when the counterflow duration T_cnt exceeds the threshold and the corrected counterflow power P'_re exceeds a1*P_re_limit, modify the continuous counterflow time T_cnt to a larger value T'_cnt; where a1 is a coefficient, 1 < a1; compare the latest T'_cnt with alpha5*T_re; where T_re is the maximum allowed continuous counterflow time, and alpha5 is a coefficient, 0 < alpha5 < 1; the value of alpha5 is selected according to the response speed of the new energy subsystem or the hydrogen production subsystem and the actual setting value of the maximum allowed continuous counterflow time T_re; if T'_cnt ≤ alpha5*T_re, simultaneously increase the power of the hydrogen production subsystem and decrease the power of the new energy subsystem to suppress the counterflow; if alpha5*T_re < T'_cnt, reduce the power of the new energy subsystem to suppress the counterflow.

15. The new energy grid-connected hydrogen production system according to any one of claims 11 to 14, characterized in that: The new energy grid-connected hydrogen production system also includes an energy storage subsystem; at this time, when the energy controller reduces the power of the new energy subsystem, it simultaneously increases the charging power of the energy storage subsystem.

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