Method and device for stabilizing power fluctuation of tie line by electrolytic aluminum load

Abstract

The invention provides a method and a device for stabilizing power fluctuation of a tie line by an electrolytic aluminum load, and relates to the technical field of power system operation and control. According to the actual condition of an electrolytic aluminum load, unbalanced power of an industrial park and an initial temperature of an electrolytic cell are input as main input variables, and an optimization target and constraint conditions of a simulated annealing algorithm are calculated; and solving the power regulation quantity which should be provided when the electrolytic aluminum load regulates the on-load voltage regulating transformer and the power regulation quantity which should be provided when the saturable reactor is regulated as output variables. And calculating the transformation ratio of the on-load voltage regulating transformer and the power deviation feedback coefficient of the saturable reactor current stabilizer. The problem that electrolytic aluminum load demand side response adjustment is extensive can be solved, and through linkage adjustment of the on-load voltage regulating transformer and the saturable reactor, the stabilizing effect of tie line power is improved. And meanwhile, the problem of falling into a local optimal solution is avoided. Finally, the method can participate in load side power demand response.

Description

Technical Field

[0001] The present invention relates to the technical field of power system operation and control, and particularly to a method and device for suppressing the power fluctuation of a tie line for an electrolytic aluminum load. Background Art

[0002] Connecting new energy power generation such as photovoltaic power generation and wind power generation systems in industrial parks, which can replace fossil fuels, can effectively reduce energy consumption and carbon emissions. However, the output of new energy has the characteristics of intermittency and large volatility. On the one hand, it may affect the stability of power supply in the industrial park, and on the other hand, it may cause load imbalance or voltage fluctuation in the power grid.

[0003] Regarding this problem, a relatively common solution is to use the charge and discharge of an energy storage system to suppress the power fluctuation on the tie line between the power grid and the industrial park. However, there are problems such as high battery costs and difficult elimination of safety hazards in high-load energy storage systems. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for suppressing the power fluctuation of a tie line for an electrolytic aluminum load, which are used to solve the problems in the prior art that suppressing the power fluctuation on the tie line between the power grid and the industrial park has high costs and difficult elimination of safety hazards, can solve the problem of rough regulation of the demand-side response of the electrolytic aluminum load, improve the suppression effect of the tie line power, and avoid falling into a local optimal solution at the same time.

[0005] To achieve the above purpose, in the first aspect, the present invention provides a method for suppressing the power fluctuation of a tie line for an electrolytic aluminum load, including: Step 1: Respectively in the first control period and the second control period, online detect the new energy output, the electrolytic aluminum load power, and the power of other loads except the electrolytic aluminum load in the industrial park, set the tie line power smoothing target and smoothing parameters, and calculate the imbalance power of the industrial park; wherein, the first control period is greater than the second control period; Step 2: Collect the initial temperature of the electrolytic cell in the first control period, calculate the control cost of the load demand response in the first control period, set the production equipment temperature index model coefficient, and obtain the penalty cost of the electrolytic aluminum load in the second control period; Step 3: In the first control period, take the imbalance power and the control cost as the optimization target and constraint conditions of the simulated annealing algorithm, and online solve the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by changing the tap ratio of the on-load tap-changer under the premise of minimizing the impact on productivity; Step 4: Obtain the difference between the actual tie-line power after changing the tap ratio of the on-load tap-changer transformer and the power smoothing target, and use the difference and the penalty cost as the optimization objective and constraint condition of the simulated annealing algorithm to online solve the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by adjusting the saturable reactor; Step 5: Obtain the power deviation feedback coefficient according to the new energy fluctuation suppression support power solved in Step 4.

[0006] According to a method for suppressing tie-line power fluctuation of electrolytic aluminum load provided by the present invention, in Step 1, the power balance equation of the industrial park is:

[0007] In the formula, is the tie-line power between the industrial park and the power grid, is the number of electrolytic aluminum loads, is the th electrolytic aluminum load power, is the power of other loads except the electrolytic aluminum load in the industrial park, is the new energy output in the industrial park; The recursive form of the tie-line power smoothing target is:

[0008] In the formula, is the tie-line power smoothing target at time t, is the tie-line power smoothing target at time, is the tie-line power without load control at time t, is the smoothing parameter, is the filtering time constant, is the first control period or the second control period; The unbalanced power of the industrial park is:

[0009] In the formula, is the unbalanced power of the industrial park at time t.

[0010] According to a method for suppressing tie-line power fluctuation of electrolytic aluminum load provided by the present invention, in Step 2, the control cost of the load demand response is:

[0011] In the formula, is the control cost of the load demand response when the power adjustment amount of the th electrolytic aluminum load is , $R$ is the revenue per unit time of the electrolytic aluminum load at the rated temperature, $\alpha$ represents the influence factor of temperature on the reaction rate of electrolytic aluminum; $C_{i}$ is the cost coefficient of the $i$-th electrolytic aluminum load considering the influence of temperature, which is related to the initial temperature of the electrolytic cell in the first control period; $T_{1}$ is the first control period. According to a method for suppressing the power fluctuation of the tie line by the electrolytic aluminum load provided by the present invention, in step 2, setting the production equipment temperature index model coefficient to obtain the penalty cost of the electrolytic aluminum load in the second control period includes: Normalizing the temperature through the production equipment temperature index model coefficient:

[0012] In the formula, $\beta_{t}$ is the production equipment temperature index model coefficient at time $t$, $T_{t}$ is the working temperature of the production equipment at time $t$, $T_{0}$ is the rated working temperature, $T_{max}$ and $T_{min}$ are the upper and lower limits of the allowable temperature of the production equipment respectively; Deriving the relationship between the production equipment temperature index model coefficient at time $t + 1$ and that at time $t$ as:

[0013] In the formula, $\beta_{t + 1}$ is the production equipment temperature index model coefficient at time $t + 1$, $\Delta P_{i,t}$ is the power regulation amount that should be provided when the $i$-th electrolytic aluminum load adjusts the on-load tap-changer at time $t$, $c_{p}$ is the specific heat capacity of the reactant $A$ in the electrolytic cell, $m$ is the mass of the reactant $A$ in the electrolytic cell; Furthermore, the penalty cost of the electrolytic aluminum load is obtained as:

[0014] Among them, $P_{i,t}$ is the penalty cost of the $i$-th electrolytic aluminum load at time $t$, $\gamma$ is the penalty cost coefficient, $T_{2}$ is the second control period.

[0015] According to a method for suppressing the power fluctuation of the tie line by the electrolytic aluminum load provided by the present invention, in step 3, online solving the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by changing the on-load tap-changer ratio under the premise of minimizing the impact on productivity includes: Set the initial temperature of the simulated annealing algorithm, the initial state of the electrolytic cell, and the number of iterations at each temperature; Determine that the power balance equation in the industrial park is:

[0016] In the formula, is the power smoothing target of the tie line at time t; is the power of the th aluminum electrolysis load at time t without load control; is the power of other loads at time t; is the new energy output in the industrial park at time t; The constraint of the tie line transmission power is:

[0017] In the formula, it is defined that the power transmitted from the industrial park to the distribution system is positive, is the maximum negative transmission power of the tie line, is the maximum positive transmission power of the tie line; Derive the power constraint condition as:

[0018] Then the coupling relationship constraint condition between the power regulation amount that should be provided when the aluminum electrolysis load adjusts the on-load tap-changer and the tap ratio of the on-load tap-changer is:

[0019] In the formula, represents the actual tap ratio of the th on-load tap-changer at time t, represents the actual tap ratio of the th on-load tap-changer at time represents the rated tap ratio of the on-load tap-changer, represents the tap position selected by the th on-load tap-changer at time t, represents the tap position selected by the th on-load tap-changer at time is the bus voltage on the high-voltage side of the industrial park, is the voltage of the th saturable reactor, are the equivalent back electromotive force and resistance of the i-th electrolytic cell respectively; The temperature constraint condition is:

[0020] The solution space S of the simulated annealing algorithm is obtained to simultaneously satisfy the power constraint condition, the coupling relationship constraint condition, and the temperature constraint condition; Taking the lowest impact of the electrothermal energy conversion of the aluminum electrolysis load on productivity as the goal, the objective function is determined as:

[0021] Arbitrarily select the th on-load tap-changer transformer, switch the tap position, and calculate the power regulation amount of the th aluminum electrolysis load after switching; It should be ensured that the after switching is still within the solution space, so a new solution space is obtained; The difference of the objective function accompanying the new solution is:

[0022] The probability of accepting the new solution is determined as:

[0023] In the formula, is the probability of accepting the new solution, and T is the current temperature of the simulated annealing algorithm; Cool down using the selected cooling coefficient until the current temperature of the simulated annealing algorithm is less than the selected termination temperature, then the simulated annealing algorithm ends, and the new energy fluctuation suppression support power that the aluminum electrolysis load should provide by changing the ratio of the on-load tap-changer transformer under the premise of the minimum impact on productivity is output.

[0024] According to a method for suppressing the power fluctuation of the tie line of the aluminum electrolysis load provided by the present invention, in step 4, the difference between the actual tie line power after changing the ratio of the on-load tap-changer transformer and the power smoothing target is:

[0025] Among them, is the difference between the actual tie line power after changing the ratio of the on-load tap-changer transformer at time t and the power smoothing target, is the tie line power without load control at time t, is the new energy fluctuation suppression support power that the

[0026] According to a method for suppressing the power fluctuation of the tie line of the aluminum electrolysis load provided by the present invention, in step 4, online solving the new energy fluctuation suppression support power that the aluminum electrolysis load should provide by adjusting the saturable reactor includes: Set the initial temperature of the simulated annealing algorithm, the initial state of the electrolytic cell, and the number of iterations at each temperature; Based on the power balance equation in the industrial park, the power transmission constraint condition of the tie line is derived as:

[0027] In the formula, is the power adjustment amount that the th aluminum electrolysis load should provide by changing the tap ratio of the on-load tap-changer transformer, is the power adjustment amount that the th aluminum electrolysis load should provide by adjusting the saturable reactor; The relationship between the DC side current of the aluminum electrolysis load and the voltage drop of the saturable reactor is expressed by the function as:

[0028] Among them, represents the DC side current of the aluminum electrolysis load, is the equivalent resistance of the electrolytic cell, is the voltage of the high-voltage side bus of the industrial park, is the voltage drop of the saturable reactor, is the equivalent back electromotive force of the electrolytic cell, is the tap ratio of the on-load tap-changer transformer; The power of the aluminum electrolysis load is expressed by the function as:

[0029] Furthermore, the coupling relationship between the power change amount of the aluminum electrolysis load and the voltage drop adjustment amount of the saturable reactor is:

[0030] In the formula, is the power change amount of the aluminum electrolysis load, is the voltage drop adjustment amount of the saturable reactor, is the voltage drop of the saturable reactor of the th aluminum electrolysis load at time t, and are the minimum and maximum values of the voltage drop adjustment range of the saturable reactor of the aluminum electrolysis load respectively;

[0031] The solution space S of the simulated annealing algorithm is obtained as simultaneously satisfying the power transmission constraint condition of the tie line, the coupling relationship between the power change amount of the aluminum electrolysis load and the voltage drop adjustment amount of the saturable reactor, and the temperature constraint condition; With the goal of minimizing the penalty cost of the aluminum electrolysis load, the objective function is determined as:

[0032] Arbitrarily select the th electrolytic aluminum load, add or subtract a random number to the current power, and this random number is related to the value range, and it should be ensured that the new solution is still within the solution space, so a new solution space is obtained ; The objective function difference associated with the new solution is:

[0033] Determine that the probability of accepting the new solution is:

[0034] In the formula, is the probability of accepting the new solution, and T is the current temperature of the simulated annealing algorithm; Use the selected cooling coefficient to cool down until the current temperature of the simulated annealing algorithm is less than the selected termination temperature, then the simulated annealing algorithm ends, and the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by adjusting the saturable reactor is output.

[0035] According to a method for suppressing the power fluctuation of the tie line by the electrolytic aluminum load provided by the present invention, step 5 specifically includes: The DC side power of the electrolytic aluminum load is:

[0036] In the formula, represents the DC side power target value of the th electrolytic aluminum load at time t, is the power of the th electrolytic aluminum load at time t without load control, is the power adjustment amount that the th electrolytic aluminum load should provide by changing the tap ratio of the on-load tap-changer at time t, is the power adjustment amount that the th electrolytic aluminum load should provide by adjusting the saturable reactor at time t; After the on-load tap-changer and the saturable reactor both participate in suppressing the power fluctuation of the tie line, the DC side current of the electrolytic aluminum load is:

[0037] In the formula, is the DC current target value of the i-th electrolytic aluminum load at time t, is the DC side power target value of the th electrolytic aluminum load at time t; Furthermore, the electrolytic aluminum load power deviation feedback coefficient is obtained as:

[0038] In the formula, is the feedback coefficient of the power deviation of the i-th aluminum electrolysis load at time t, is the direct current side current of the i-th aluminum electrolysis load at time t. According to a method for suppressing the power fluctuation of the tie line of the aluminum electrolysis load provided by the present invention, the first control period is 1 hour, and the second control period is 30 seconds. In a second aspect, the present invention provides a device for suppressing the power fluctuation of the tie line of the aluminum electrolysis load, including: A detection unit, configured to respectively detect the new energy output, the aluminum electrolysis load power, and the power of other loads except the aluminum electrolysis load in the industrial park during the first control period and the second control period, set the tie line power smoothing target and smoothing parameters, and calculate the imbalance power of the industrial park; wherein, the first control period is greater than the second control period; An acquisition unit, configured to acquire the initial temperature of the electrolytic cell during the first control period, calculate the control cost of the load demand response during the first control period, set the production equipment temperature index model coefficient, and obtain the penalty cost of the aluminum electrolysis load during the second control period; A first solution unit, configured to use the imbalance power and the control cost as the optimization target and constraint conditions of the simulated annealing algorithm during the first control period, and online solve the new energy fluctuation suppression support power that the aluminum electrolysis load should provide by changing the tap ratio of the on-load tap-changer on the premise of minimizing the impact on productivity; A second solution unit, configured to obtain the difference between the actual tie line power and the power smoothing target after changing the tap ratio of the on-load tap-changer, and use the difference and the penalty cost as the optimization target and constraint conditions of the simulated annealing algorithm, and online solve the new energy fluctuation suppression support power that the aluminum electrolysis load should provide by adjusting the saturation reactor; A feedback unit, configured to obtain the power deviation feedback coefficient according to the new energy fluctuation suppression support power solved by the second solution unit.

[0039] The technical solution of the present invention at least has the following technical effects: A method and device for suppressing the power fluctuation of the tie line for electrolytic aluminum load. According to the actual situation of the electrolytic aluminum load, the unbalanced power input to the industrial park and the initial temperature of the electrolytic cell are used as the main input variables, the optimization objective and constraint conditions of the simulated annealing algorithm are calculated, and the power adjustment amount that should be provided when the electrolytic aluminum load adjusts the on-load tap-changer and the power adjustment amount that should be provided when adjusting the saturable reactor are used as output variables. Then, the tap ratio of the on-load tap-changer and the power deviation feedback coefficient of the steady current device of the saturable reactor are calculated. The present invention can solve the problem of rough regulation of the demand-side response of the electrolytic aluminum load, improve the suppression effect of the tie line power through the coordinated regulation of the on-load tap-changer and the saturable reactor, and at the same time avoid the problem of falling into a local optimal solution. Finally, the present invention can participate in the power demand response on the load side. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in 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 some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] In the drawings: Figure 1 is a flowchart of the method for suppressing the power fluctuation of the tie line for electrolytic aluminum load according to the present invention; Figure 2 is a graph showing the relationship between the tie line power and time according to the present invention; Figure 3 is a graph showing the relationship between the value of the objective function and the number of iterations in the process of the simulated annealing algorithm according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0043] The following will describe in detail some embodiments of the present invention in conjunction with the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0044] Based on the characteristics of large regulation capacity and flexible regulation of the electrolytic aluminum load, the present invention provides a method for suppressing the power fluctuation of the tie line on multiple time scales, realizing the linkage of the on-load tap-changer and the saturable reactor, and making the suppression effect more excellent. And the simulated annealing algorithm is used to enhance the global search ability, which can provide a stable and reliable solution, and the algorithm is easy to understand and relatively simple to implement.

[0045] Please refer to Figure 1 , an embodiment of the present invention provides a method for suppressing the power fluctuation of the tie line of the electrolytic aluminum load, including the following steps: Step 1: Respectively in the first control period and the second control period, online detect the new energy output, the electrolytic aluminum load power, and the power of other loads except the electrolytic aluminum load in the industrial park, set the tie line power smoothing target and smoothing parameters, and calculate the unbalanced power of the industrial park; wherein, the first control period is greater than the second control period; Specifically, in this embodiment, the first control period is 1 hour, and the second control period is 30 seconds. The power mentioned in the present invention all refers to the active power.

[0046] In step 1, on the premise of ignoring the line loss, the power balance equation of the industrial park is:

[0047] Among them, is the tie line power between the industrial park and the power grid, is the number of electrolytic aluminum loads, is the th electrolytic aluminum load power, is the power of other loads except the electrolytic aluminum load in the industrial park, is the new energy output in the industrial park, that is, the total new energy power.

[0048] The recursive form of the tie line power smoothing target is:

[0049] Among them, is the tie line power smoothing target at time t, is the time tie line power smoothing target, is the tie line power without load control at time t, is the smoothing parameter, is the filtering time constant, is the first control period or the second control period. The smaller

[0050] Therefore, the unbalanced power that needs to be adjusted in the industrial park is

[0051] In the formula, is the unbalanced power of the industrial park at time t.

[0052] Step 2: Collect the initial temperature of the electrolytic cell in the first control period, calculate the control cost of the load demand response in the first control period, set the model coefficient of the production equipment temperature index, and obtain the penalty cost of the electrolytic aluminum load in the second control period; 2.1) When the first control period (i.e., the sampling time interval) is Considering the influence of temperature on the chemical reaction rate, current efficiency, and service life of the equipment, and the coupling relationship between the control cost generated by the temperature change and the active power regulation amount of the saturable reactor, that is, the control cost of the load demand response is:

[0053] Among them, is the th electrolytic aluminum load power regulation amount is when the control cost of the load demand response. is the income per unit time of the electrolytic aluminum load at the rated temperature. represents the influence factor of temperature on the reaction rate of electrolytic aluminum, and takes 2 - 4 in practical applications. is the th electrolytic aluminum load cost coefficient considering the influence of temperature, related to the initial temperature of the electrolytic cell in the first control period, and the first control period .

[0054] When the sampling time interval is the active power regulation amount will seriously affect the temperature of the electrolytic cell. Therefore, a model coefficient of the production equipment temperature index is set to normalize the temperature:

[0055] Among them, is the model coefficient of the production equipment temperature index at time t, is the working temperature of the production equipment at time t, is the rated working temperature, are the upper and lower limits of the allowable temperature of the production equipment respectively. To ensure production safety, therefore .

[0056] 2.2) When the sampling time interval is At this time, within this sampling time interval, the temperature change of the electrolytic cell is not significant. Under this sampling time interval, considering using temperature to reflect production efficiency, when The greater the absolute value of The greater the absolute value of

[0057] According to the law of conservation of energy, the heat balance equation is:

[0058] Among them, Is the energy change in the reaction vessel within the sampling time interval; Is the reactant Specific heat capacity; Is the reactant Mass of Is the temperature change in the reaction vessel within the sampling time interval.

[0059] When the regulation amount of electrolytic aluminum load is , the active power regulation amount of the electrolytic aluminum load is:

[0060] Among them, Is the active power regulation amount of the electrolytic aluminum load at time t .

[0061] Then The temperature of the production equipment of the electrolytic aluminum load at time Is:

[0062] Therefore, the relationship between the production equipment temperature index coefficients At time t+1 and time t can be deduced:

[0063] Considering the relationship between temperature , the production equipment temperature as the standard model coefficient And the penalty cost, the penalty cost of the electrolytic aluminum load at time t is:

[0064] Among them, Is the penalty cost of the th electrolytic aluminum load at time t, Is the penalty cost coefficient, taking a constant value, Is the second control period.

[0065] Step 3: During the first control period, take the unbalanced power and control cost as the optimization objective and constraint conditions of the simulated annealing algorithm, and online solve the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by changing the tap ratio of the on-load tap-changer under the premise of minimizing the impact on productivity. Specifically, in Step 3, online solve the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by changing the tap ratio of the on-load tap-changer under the premise of minimizing the impact on productivity and the tap ratio of the on-load tap-changer , and the specific process is described as follows: 3.1) Initialization Set the initial temperature T (sufficiently large) of the simulated annealing algorithm, select the initial state. In the present invention, the rated state of each electrolytic cell is selected as the initial state, and set the number of iterations L at each temperature.

[0066] 3.2) Solution space S 3.2.1) The power balance equation in the industrial park is:

[0067] In the formula, is the power smoothing target of the tie line at time t; is the power of the th electrolytic aluminum load at time t without load control; is the power of other loads at time t; is the new energy output in the industrial park at time t.

[0068] The tie line transmission power constraint is:

[0069] Define the power transmitted from the industrial park to the distribution system as positive, is the maximum negative transmission power of the tie line, is the maximum positive transmission power of the tie line.

[0070] The power constraint condition can be deduced as:

[0071] Among them, is the power adjustment amount that the th electrolytic aluminum load should provide when adjusting the on-load tap-changer at time t.

[0072] It should be noted that there are various loads in the industrial park, and a new energy power generation system is also connected. Since the power generation of the new energy power generation system is unstable, while the power consumed by the remaining loads is relatively stable, the total power consumed by the entire industrial park is unstable. As a result, the power on the connection line between the entire industrial park and the power grid is unstable. The present invention mainly relies on adjusting the electrolytic aluminum load to suppress the power fluctuation on the connection line between the industrial park and the power grid. Here, the distribution system refers to the section from the outlet of the step-down distribution substation to the user side (i.e., the industrial park) in the power system.

[0073] 3.2.2) The on-load tap-changer transformer has discrete regulation, and the regulation range is 3×2.5%. In order to utilize the on-load tap-changer transformer for voltage regulation, tap-changers are provided on the high-voltage side of the transformer. Generally, seven tap-changers are set, namely 1.075 、1.05 、1.025 、 、0.975 、0.95 、0.925 , ( refers to the rated voltage of the high-voltage side of the transformer), so the voltage regulation range is ±3×2.5%.

[0074] Then the coupling relationship between the on-load tap-changer transformer and the electrolytic aluminum load power:

[0075] Among them, represents the actual transformation ratio of the th on-load tap-changer transformer, represents the rated transformation ratio of the on-load tap-changer transformer, represents the tap-changer position selected for the th on-load tap-changer transformer. is the bus voltage of the high-voltage side of the industrial park, is the voltage of the saturable reactor, is the equivalent back electromotive force and resistance of the electrolytic cell.

[0076] Then the coupling relationship constraint condition between the power regulation amount that should be provided when the electrolytic aluminum load adjusts the on-load tap-changer transformer and the transformation ratio of the on-load tap-changer transformer is:

[0077] Substituting the above formula, we can obtain:

[0078] In the formula, represents the actual transformation ratio of the th on-load tap-changer transformer at time t, represents The actual transformation ratio of the on-load tap-changer transformer at the t-th moment, the tap position selected by the on-load tap-changer transformer at the t-th moment, the tap position selected by the n-th saturated reactor voltage, the equivalent back electromotive force and resistance of the i-th electrolytic cell respectively.

[0079] 3.2.3) Temperature constraint condition Given the temperature index model coefficients of the production equipment :

[0080] During the sampling time interval of Δt, the temperature of the production equipment does not exceed its upper and lower temperature limits, that is, the temperature constraint:

[0081] Therefore, there is:

[0082] Therefore, the solution space S of the simulated annealing algorithm is obtained as the set of solutions that simultaneously satisfy the above power constraint conditions, coupling relationship constraint conditions, and temperature constraint conditions, and can be expressed as:

[0083] In the formula, represents the electrolytic aluminum load power regulation amount when the tap position is selected at the t-th moment.

[0084] 3.3) Objective function Taking the lowest impact of the electrothermal energy conversion of the electrolytic aluminum load on productivity as the goal, the objective function is determined as:

[0085] 3.4) Generation of new solutions Arbitrarily select the n-th on-load tap-changer transformer, switch the tap position, and calculate the electrolytic aluminum load power regulation amount ΔPn after the switch. It should be ensured that the ΔPn after the switch is still in the solution space, so a new solution space S' is obtained.

[0086] Therefore, the new set of electrolytic aluminum load power regulation amounts is obtained as: 。

[0087] 3.5) Objective function difference The objective function difference associated with the new solution is as follows:

[0088] Wherein, and respectively represent the set of the original electrolytic aluminum load power regulation amounts and the set of the power regulation amounts after generating the new solution.

[0089] 3.6) Acceptance criterion Since the objective is to minimize the impact of the electrolytic aluminum load electrothermal energy conversion on productivity, the probability of accepting the new solution is determined as:

[0090] In the formula, is the probability of accepting the new solution, and T is the current temperature of the simulated annealing algorithm.

[0091] 3.7) Temperature reduction Use the selected temperature reduction coefficient to perform temperature reduction, and take the new temperature as (T is the temperature of the previous iteration), and can be selected.

[0092] 3.8) End condition Use the selected termination temperature to determine whether the annealing process ends. If then the annealing process ends, and the current state is output, that is, temperature reduction is performed using the selected temperature reduction coefficient until the current temperature of the simulated annealing algorithm is less than the selected termination temperature, then the simulated annealing algorithm ends, and the power support for suppressing the new energy fluctuation that the electrolytic aluminum load should provide by changing the tap ratio of the on-load tap-changer under the premise of minimizing the impact on productivity is output.

[0093] It should be noted that in the present invention, the method of adjusting the tap ratio of the on-load tap-changer to adjust the active power of the electrolytic aluminum load relies on the mechanical change of the on-load tap-changer tap, and the time for switching from one gear to another is relatively long, which is mainly used to solve the steady-state scheduling problem with a relatively long time scale. In order to enable the electrolytic aluminum active load to continuously and quickly follow the new energy fluctuation, on the basis of adjusting the tap ratio of the on-load tap-changer, the present invention will also consider introducing the tie-line power deviation within the 1h time scale into the steady current device of the saturable reactor, and adjusting the saturable reactor voltage drop to control the electrolytic aluminum active power.

[0094] Step 4: Obtain the difference between the actual tie-line power after changing the tap ratio of the on-load tap-changer transformer and the power smoothing target, and use the difference and the penalty cost as the optimization objective and constraint conditions of the simulated annealing algorithm to online solve the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by adjusting the saturable reactor; In Step 4, the difference between the actual tie-line power after the adjustment in Step 3 and the power smoothing target is:

[0095] wherein, is the difference between the actual tie-line power after changing the tap ratio of the on-load tap-changer transformer at time t and the power smoothing target, is the tie-line power without load control at time t, is the new energy fluctuation suppression support power that the i-th electrolytic aluminum load should provide by changing the tap ratio of the on-load tap-changer transformer at time t.

[0096] Specifically, the specific process of online solving the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by adjusting the saturable reactor is as follows: 4.1) Initialization Set the initial temperature T (sufficiently large) of the simulated annealing algorithm, select the initial state. In the present invention, the rated state of each electrolytic cell is selected as the initial state, and set the number of iterations L at each temperature.

[0097] 4.2) Solution space S 4.2.1) Similar to the above, through the power balance equation in the industrial park, the tie-line transmission power constraint condition can be deduced as:

[0098] wherein, is the power adjustment amount that the -th electrolytic aluminum load should provide by changing the tap ratio of the on-load tap-changer transformer at time t, is the power adjustment amount that the -th electrolytic aluminum load should provide by adjusting the saturable reactor at time t.

[0099] 4.2.2) The current adjustment amount of the electrolytic aluminum load mainly depends on the adjustment range of the voltage drop of the saturable reactor of the electrolytic aluminum load, that is

[0100] According to the working principle of the electrolytic aluminum load, the relationship between the DC side current of the electrolytic aluminum load and the voltage drop of the saturable reactor can be represented by the function as:

[0101] Among them, represents the direct current side current of the electrolytic aluminum load, is the equivalent resistance of the electrolytic cell, is the bus voltage on the high-voltage side of the industrial park, is the voltage drop of the saturable reactor, is the equivalent back electromotive force of the electrolytic cell, is the transformation ratio of the on-load tap-changer transformer.

[0102] The power of the electrolytic aluminum load can be expressed by the function as follows:

[0103] Therefore, the change in the power of the electrolytic aluminum load and the regulation amount of the voltage drop of the saturable reactor have the following coupling relationship:

[0104] And there is:

[0105] In the formula, is the change in the power of the electrolytic aluminum load, is the regulation amount of the voltage drop of the saturable reactor, is the voltage drop of the saturable reactor of the i-th electrolytic aluminum load at time t, are respectively the minimum and maximum values of the regulation range of the voltage drop of the saturable reactor of the electrolytic aluminum load.

[0106] 4.2.3) Production safety During the sampling time interval, the temperature of the production equipment shall not exceed its upper and lower limits, which can be expressed in terms of the model coefficient of the production equipment temperature index as:

[0107] Similar to the above text, there is:

[0108] Therefore, the solution space S of the simulated annealing algorithm is the set of all elements that simultaneously satisfy the above-mentioned tie-line transmission power constraint conditions, the coupling relationship between the change in the power of the electrolytic aluminum load and the regulation amount of the voltage drop of the saturable reactor, and the temperature constraint conditions, and can be expressed as:

[0109] Any element in it meets the above three conditions.

[0110] 4.3) Objective function Taking the minimum penalty cost of electrolytic aluminum load as the goal, the objective function is determined as follows:

[0111] 4.4) Generation of new solutions Arbitrarily select the th electrolytic aluminum load, and add or subtract a random number to the current power. This random number is related to the value range, and it should be ensured that the new solution is still within the solution space. Therefore, a new solution space is obtained. Thus, we have:

[0112] Among them, represents the new solution generated by this temperature reduction, and represents the original adjustment amount of the th electrolytic aluminum load.

[0113] The set of new electrolytic aluminum load power adjustment amounts obtained is:

[0114] 4.5) Objective function difference The objective function difference accompanying the new solution is:

[0115] Among them and respectively represent the set of original electrolytic aluminum load active power adjustment amounts and the set of active power adjustment amounts after generating the new solution.

[0116] 4.6) Acceptance criterion Since the goal is to minimize the penalty cost, the acceptance criterion is:

[0117] In the formula, is the probability of accepting the new solution, and T is the current temperature of the simulated annealing algorithm.

[0118] 4.7) Temperature reduction and termination condition Similar to the previous steps, use the selected temperature reduction coefficient to reduce the temperature. Take the new temperature as (T is the temperature of the previous iteration), select , and use the selected termination temperature to judge whether the annealing process is over. If Then the algorithm ends and outputs the current state. That is, cooling is carried out using the selected cooling coefficient until the current temperature of the simulated annealing algorithm is less than the selected termination temperature, then the simulated annealing algorithm ends, and the new energy fluctuation suppression support power that the electrolytic aluminum load should provide by adjusting the saturable reactor is output.

[0119] Step 5: Obtain the power deviation feedback coefficient based on the new energy fluctuation suppression support power solved in Step 4.

[0120] In actual production, the electrolytic aluminum load generally uses a current stabilizing device with a PI control link in its control principle to automatically control the voltage drop of the saturable reactor to maintain the stability of the DC side voltage, current, and active power. Now, consider adding the feedback of the active power adjustment amount of the electrolytic aluminum load to the current stabilizing device of the saturable reactor, so as to introduce the active power adjustment amount of the electrolytic aluminum load caused by the fluctuation of the renewable new energy output into the current stabilizing device and realize the control of the saturable reactor.

[0121] Consider the following inertia link, whose transfer function is:

[0122] Among them, is the inertia time constant, which will affect the response time of the electrolytic aluminum load control and can effectively avoid the frequent back-and-forth movement of the reactor, and is selected according to actual needs. is the power deviation feedback coefficient of the electrolytic aluminum load.

[0123] The adjusted DC side power of the electrolytic aluminum can be expressed as:

[0124] Among them, represents the DC side power target value of the th electrolytic aluminum at time t, is the th electrolytic aluminum load power at time t without load control, is the power adjustment amount that the th electrolytic aluminum load should provide when adjusting the on-load tap-changer at time t, is the active power adjustment amount that the th electrolytic aluminum load should provide when adjusting the saturable reactor at time t.

[0125] As mentioned above, according to the working principle of the electrolytic aluminum load, the electrolytic aluminum load power can be expressed as:

[0126] Among them, represents the DC side current of the electrolytic aluminum load, is the equivalent resistance of the electrolytic cell, is the equivalent back electromotive force of the electrolytic cell, is the tap-changing ratio of the on-load tap-changer transformer.

[0127] It is easy to know that:

[0128] By using the quadratic formula, it can be solved that:

[0129] where is the DC current target value of the i-th aluminum electrolysis load at time t, represents the DC side power target value of the -th aluminum electrolysis load at time t.

[0130] Therefore, the power deviation feedback coefficient of the aluminum electrolysis load at time t is:

[0131] where, is the power deviation feedback coefficient of the i-th aluminum electrolysis load at time t, is the DC side current of the i-th aluminum electrolysis load at time t.

[0132] Based on the same inventive concept, another embodiment of the present invention provides a device for suppressing the power fluctuation of the tie line of the aluminum electrolysis load. This device corresponds to the method of the foregoing embodiment. The device includes: A detection unit, configured to online detect the new energy output, the aluminum electrolysis load power, and the power of other loads except the aluminum electrolysis load in the industrial park respectively within the first control period and the second control period, set the tie line power smoothing target and smoothing parameters, and calculate the imbalance power of the industrial park; wherein, the first control period is greater than the second control period; An acquisition unit, configured to acquire the initial temperature of the electrolytic cell within the first control period, calculate the control cost of the load demand response within the first control period, set the production equipment temperature index model coefficient, and obtain the penalty cost of the aluminum electrolysis load within the second control period; A first solving unit, configured to, within the first control period, take the imbalance power and the control cost as the optimization objective and constraint conditions of the simulated annealing algorithm, and online solve the new energy fluctuation suppression support power that the aluminum electrolysis load should provide by changing the tap-changing ratio of the on-load tap-changer transformer on the premise of minimizing the impact on productivity; A second solving unit, configured to obtain the difference between the actual tie line power and the power smoothing target after changing the tap-changing ratio of the on-load tap-changer transformer, take the difference and the penalty cost as the optimization objective and constraint conditions of the simulated annealing algorithm, and online solve the new energy fluctuation suppression support power that the aluminum electrolysis load should provide by adjusting the saturation reactor; A feedback unit, configured to obtain a power deviation feedback coefficient according to the new - energy fluctuation suppression support power solved by a second solving unit.

[0133] The following is a specific embodiment of the present invention.

[0134] In this embodiment, there are only two aluminum - electrolysis loads in the industrial park, and the rated values of the bus voltage on the high - voltage side of the industrial park , the tap - changer ratio of the on - load tap - changing transformer are 220V and 146.56 respectively, and the tap position is 3×2.5%. The equivalent back - electromotive force of the electrolytic cell , and the equivalent resistance of the electrolytic cell . The rated value of the initial voltage drop of the saturable reactor is 35V, and the upper and lower limits of the saturable reactor voltage are 0V and 70V respectively. The initial temperature of the electrolytic cells are all the rated temperature of 960 ; the upper and lower temperature limits are 950 and 970 . The income per unit time of the aluminum - electrolysis load at the rated temperature is related to the aluminum price, market supply - demand relationship, etc. Here, yuan is taken, and the mass of electrolytic aluminum is taken as 35 tons per cell. The output curve of renewable new energy in the industrial park is known. The predicted powers of each aluminum - electrolysis load per day are 200MW and 200MW respectively, and other loads are 20MW; the first control period , the second control period . The cost coefficients of the two aluminum - electrolysis loads considering the temperature effect. The influence factor of temperature on the reaction rate of electrolytic aluminum = 3. The smoothing parameter Figure 2 shows the changes in the original tie - line power, the tie - line power smoothing target, and the tie - line power after the on - load tap - changing transformer and the saturable reactor participate in the suppression in this embodiment. Figure 3 shows the change of the objective - function value with the number of iterations during the simulated annealing algorithm in this embodiment. It can be clearly seen that as the number of iterations increases, the objective - function value gradually approaches the minimum value.

[0135] In summary, the method and device for suppressing the tie - line power fluctuation of the aluminum - electrolysis load provided by the present invention take the unbalanced power input into the industrial park and the initial temperature of the electrolytic cell as the main input variables according to the actual situation of the aluminum - electrolysis load, calculate the optimization objective and constraint conditions of the simulated annealing algorithm, and solve the power adjustment amount that should be provided when the aluminum - electrolysis load adjusts the on - load tap - changing transformer and the power adjustment amount that should be provided when adjusting the saturable reactor​ is the output variable. Then, calculate the tap-changing ratio of the on-load tap-changer transformer and the power deviation feedback coefficient of the current-stabilizing device of the saturable reactor. The present invention can solve the problem of rough regulation of the load demand-side response in electrolytic aluminum. Through the coordinated regulation of the on-load tap-changer transformer and the saturable reactor, the smoothing effect of the tie-line power is improved. At the same time, the problem of falling into a local optimal solution is avoided. Finally, the present invention can be used to participate in the load-side power demand response.

[0136] After considering the specification and the embodiments disclosed herein, those skilled in the art will readily conceive of other embodiments of the present invention. The present invention is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field not disclosed in the present invention. It should be understood that the present invention is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load, characterized in that: include: Step 1: In the first control cycle and the second control cycle, respectively, online detect the output of new energy, the electrolytic aluminum load power and other load powers except the electrolytic aluminum load in the industrial park, set the tie line power smoothing target and smoothing parameters, and calculate the unbalanced power of the industrial park; wherein the first control cycle is greater than the second control cycle; Step 2: Collect the initial temperature of the electrolytic cell in the first control period, calculate the control cost of the load demand response in the first control period, set the temperature index model coefficient of the production equipment, and obtain the penalty cost of the electrolytic aluminum load in the second control period; Step 3: In the first control cycle, the unbalanced power and control cost are used as the optimization target and constraint conditions of the simulated annealing algorithm, and the new energy fluctuation smoothing support power that should be provided by the electrolytic aluminum load by changing the ratio of the on-load tap-changing transformer under the premise of minimizing the impact on productivity is solved online; Step 4: Obtain the difference between the actual interconnection line power and the power smoothing target after changing the transformation ratio of the on-load tap-changing transformer, use the difference and penalty cost as the optimization target and constraint condition of the simulated annealing algorithm, and solve online the new energy fluctuation smoothing support power that the electrolytic aluminum load should provide by adjusting the saturated reactor; Step 5: derive the power deviation feedback coefficient according to the new energy fluctuation smoothing support power solved in step 4.

2. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 1 is characterized in that: In step 1, the power balance equation of the industrial park is: In the formula, is the power of the interconnection line between the industrial park and the power grid, is the number of electrolytic aluminum loads, For the Aluminum electrolytic load power, The power of other loads in the industrial park except for the electrolytic aluminum load. Contribute to new energy sources in the industrial park; The recursive form of the tie line power smoothing target is: In the formula, is the power smoothing target of the tie line at time t, for The power smoothing target of the interconnection line at all times, is the power of the tie line when no load control is applied at time t, is the smoothing parameter, is the filtering time constant, is the first control cycle or the second control cycle; The unbalanced power of the industrial park is: In the formula, is the unbalanced power of the industrial park at time t.

3. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 2 is characterized in that: In step 2, the control cost of the load demand response is: In the formula, For the The power regulation of electrolytic aluminum load is The control cost of load demand response is is the revenue per unit time of electrolytic aluminum load at rated temperature, Indicates the influence factor of temperature on the reaction rate of electrolytic aluminum; For the The cost coefficient of each electrolytic aluminum load considering the temperature effect is related to the initial temperature of the electrolytic cell in the first control period; It is the first control cycle.

4. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 3 is characterized in that: In step 2, the temperature index model coefficient of the production equipment is set to obtain the penalty cost of the electrolytic aluminum load in the second control period, including: The temperature is normalized by the production equipment temperature index model coefficient: In the formula, is the temperature index model coefficient of the production equipment at time t, is the working temperature of the production equipment at time t, is the rated operating temperature, They are the upper and lower limits of the permissible temperature for production equipment respectively; The relationship between the temperature index model coefficients of the production equipment at time t+1 and time t is derived as follows: In the formula, is the temperature index model coefficient of the production equipment at time t+1, is the time t The power regulation amount that should be provided when adjusting the load voltage regulating transformer for electrolytic aluminum load is Reactants in the electrolytic cell The specific heat capacity, Reactants in the electrolytic cell quality; Then the penalty cost of electrolytic aluminum load is obtained as follows: in, For the The penalty cost of an electrolytic aluminum load at time t is: is the penalty cost coefficient, This is the second control cycle.

5. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 4 is characterized in that: In step 3, the online solution of the new energy fluctuation smoothing support power that should be provided by the electrolytic aluminum load by changing the ratio of the on-load tap-changing transformer under the premise of minimal impact on productivity includes: Set the initial temperature of the simulated annealing algorithm, the initial state of the electrolytic cell, and the number of iterations at each temperature; The power balance equation in the industrial park is determined as: In the formula, is the tie line power smoothing target at time t; The time t is the time when there is no load control. Aluminum electrolytic load power; is the power of other loads at time t; Contribute to the new energy in the industrial park at time t; The transmission power constraint of the tie line is: In the formula, the power transmitted from the industrial park to the distribution system is defined as positive. is the maximum negative transmission power of the tie line, is the maximum forward transmission power of the tie line; The power constraint is derived as: The coupling relationship constraint between the power regulation amount that should be provided when the electrolytic aluminum load regulates the on-load tap-changing transformer and the on-load tap-changing transformer ratio is: In the formula, Indicates the time t The actual transformation ratio of an on-load tap-changing transformer, express Moment The actual transformation ratio of an on-load tap-changing transformer, Indicates the rated transformation ratio of the on-load tap-changing transformer. Indicates the time t The tap position selected by the on-load tap-changing transformer, express Moment The tap position selected by the on-load tap-changing transformer, is the bus voltage on the high-voltage side of the industrial park, For the Saturated reactor voltage, are the equivalent back electromotive force and resistance of the i-th electrolytic cell respectively; The temperature constraints are: The solution space S of the simulated annealing algorithm is obtained to satisfy the power constraint condition, the coupling relationship constraint condition and the temperature constraint condition at the same time; With the goal of minimizing the impact of electrolytic aluminum load electric heat energy conversion on productivity, the objective function is determined as: Choose any An on-load tap-changing transformer switches the tap position and calculates the Aluminum electrolytic load power regulation , it should be ensured that after switching Still in the solution space, so we get a new solution space ; The objective function difference with the new solution for: The probability of accepting the new solution is determined as: In the formula, is the probability of accepting a new solution, T is the current temperature of the simulated annealing algorithm; The selected cooling coefficient is used to cool the temperature until the current temperature of the simulated annealing algorithm is less than the selected termination temperature. The simulated annealing algorithm ends and the output is the new energy fluctuation smoothing support power that should be provided by changing the transformation ratio of the on-load tap-changing transformer under the premise of minimizing the impact on productivity.

6. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 5 is characterized in that: In step 4, the difference between the actual tie line power and the power smoothing target after changing the transformation ratio of the on-load tap-changing transformer is: in, is the difference between the actual tie line power and the power smoothing target after the on-load tap-changing transformer ratio is changed at time t, is the interconnection line power when no load control is applied at time t, The new energy fluctuation smoothing support power that should be provided by changing the transformation ratio of the on-load tap-changing transformer for the i-th electrolytic aluminum load at time t.

7. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 6 is characterized in that: In step 4, the online solution of the new energy fluctuation smoothing support power that the electrolytic aluminum load should provide by adjusting the saturated reactor includes: Set the initial temperature of the simulated annealing algorithm, the initial state of the electrolytic cell, and the number of iterations at each temperature; Through the power balance equation in the industrial park, the transmission power constraint of the tie line is derived as follows: In the formula, is the time t The power regulation amount that should be provided by changing the ratio of the on-load tap-changing transformer for each electrolytic aluminum load is: is the time t The power regulation amount that an electrolytic aluminum load regulation saturated reactor should provide; The relationship between the DC side current of the electrolytic aluminum load and the saturated reactor voltage drop is expressed by the function It is expressed as: in, Indicates the DC side current of electrolytic aluminum load, is the equivalent resistance of the electrolytic cell, is the bus voltage on the high-voltage side of the industrial park, is the saturated reactor voltage drop, is the equivalent back electromotive force of the electrolytic cell, is the transformation ratio of the on-load tap-changing transformer; Electrolytic aluminum load power Through the function It is expressed as: Furthermore, the coupling relationship between the change in electrolytic aluminum load power and the saturated reactor voltage drop adjustment is: In the formula, is the change in electrolytic aluminum load power, is the saturated reactor voltage drop adjustment value, is the voltage drop of the saturated reactor of the i-th electrolytic aluminum load at time t, They are the minimum and maximum values ​​of the voltage drop adjustment range of the saturated reactor for electrolytic aluminum load, respectively; The temperature constraints are: The solution space S of the simulated annealing algorithm is obtained to simultaneously satisfy the transmission power constraint of the tie line, the coupling relationship between the change in power of the electrolytic aluminum load and the voltage drop adjustment amount of the saturated reactor, and the temperature constraint; Taking the minimum penalty cost of electrolytic aluminum load as the goal, the objective function is determined as: Choose any electrolytic aluminum load, add or subtract a random number from the current power, and the random number is The value range of the new solution should be Still in the solution space, so we get a new solution space ; The objective function difference with the new solution for: The probability of accepting the new solution is determined as: In the formula, is the probability of accepting a new solution, T is the current temperature of the simulated annealing algorithm; The selected cooling coefficient is used to cool the system until the current temperature of the simulated annealing algorithm is less than the selected termination temperature. The simulated annealing algorithm ends and the output electrolytic aluminum load is supported by adjusting the new energy fluctuations that the saturated reactor should provide to smooth the power.

8. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 7 is characterized in that: The step 5 specifically includes: The DC side power of electrolytic aluminum load is: In the formula, Indicates the time t The DC power target value of the electrolytic aluminum load is The time t is the time when there is no load control. Aluminum electrolytic load power, is the time t The power regulation amount that the on-load tap-changing transformer ratio should provide for each aluminum electrolytic load change is is the time t The power regulation amount that an electrolytic aluminum load regulation saturated reactor should provide; After both the on-load tap-changing transformer and the saturated reactor participate in smoothing the power fluctuation of the interconnection line, the DC side current of the electrolytic aluminum load is: In the formula, is the DC current target value of the ith electrolytic aluminum load at time t, is the DC side power target value of the ith electrolytic aluminum load at time t; Then the power deviation feedback coefficient of electrolytic aluminum load is obtained as follows: In the formula, is the power deviation feedback coefficient of the ith electrolytic aluminum load at time t, is the DC side current of the i-th electrolytic aluminum load at time t.

9. The method for smoothing the power fluctuation of the interconnection line by electrolytic aluminum load according to claim 1, characterized in that: The first control period is 1 hour, and the second control period is 30 seconds.

10. A device for smoothing the power fluctuation of the interconnection line for electrolytic aluminum load, characterized in that: include: The detection unit is used to detect the output of new energy, the power of electrolytic aluminum load and other load powers other than the electrolytic aluminum load in the industrial park online in the first control cycle and the second control cycle, set the tie line power smoothing target and smoothing parameters, and calculate the unbalanced power of the industrial park; wherein the first control cycle is greater than the second control cycle; The collection unit is used to collect the initial temperature of the electrolytic cell in the first control period, calculate the control cost of the load demand response in the first control period, set the temperature index model coefficient of the production equipment, and obtain the penalty cost of the electrolytic aluminum load in the second control period; The first solving unit is used to use the unbalanced power and control cost as the optimization target and constraint conditions of the simulated annealing algorithm in the first control cycle, and solve online the new energy fluctuation smoothing support power that should be provided by the electrolytic aluminum load by changing the transformation ratio of the on-load tap-changing transformer under the premise of minimizing the impact on productivity; The second solving unit is used to obtain the difference between the actual interconnection line power and the power smoothing target after changing the transformation ratio of the on-load tap-changing transformer, and use the difference and the penalty cost as the optimization target and constraint condition of the simulated annealing algorithm to solve online the new energy fluctuation smoothing support power that the electrolytic aluminum load should provide by adjusting the saturated reactor; A feedback unit is used to obtain a power deviation feedback coefficient according to the new energy fluctuation smoothing support power solved by the second solving unit.

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