A method for assisting decision on start and stop of generator set based on minimum operation principle

Abstract

The application provides a kind of generator set start-stop auxiliary decision-making method based on minimum operation principle, through the analysis of the process of hydropower station unit start-stop, combined with water head, unit vibration area, load curve, based on the minimum start-stop operation principle, the theoretical optimal start-stop quantity of different time under actual complex production condition is researched, the intelligent guidance of start-stop operation is realized, early warning is realized, and priority selection of start-stop is provided according to unit operation state data and artificial priority setting. Through the trend analysis of the load of each negative time point of the dispatching plan load curve, the unique load trend at any time point is determined, so as to complete the calculation of the theoretical optimal unit start number at each time based on the minimum operation principle, determine the optimal unit operation quantity at each time, and complete the auxiliary decision-making of start-stop operation by comparing the optimal start number calculated in the future time with the current unit operation quantity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water turbine start-stop control, in particular to a generator set start-stop auxiliary decision-making method based on minimum operation principle. BACKGROUND

[0002] Due to the characteristics of water power station unit, such as rapid start-stop, high control precision, flexible operation, and quick response to load change of power system, the unit mainly undertakes the task of peak regulation and frequency regulation in power grid. With the rapid economic development, the peak-valley difference of power grid load is increasing, and the peak regulation range is also increasing. This inevitably causes more frequent start-stop operation. At present, the artificial calculation and judgment method is adopted for the start-stop operation of large-scale water turbine generator set. According to the load curve issued by the dispatcher, the constraint conditions such as unit vibration zone, and the operation personnel of power plant calculate and adjust the unit operation state according to different planned load. The operation personnel are tested by frequent start-stop operation. According to the statistics, the average start-stop times of 12 units of a large-scale hydropower station are more than 5000 times a year, and the maximum start-stop times in a single day are more than 30 times. The operation personnel calculate the number of units connected to the grid according to the load plan of different time periods and the current water head output range, and make comprehensive decision and judgment on start-stop operation. This method of relying only on artificial calculation and judgment for unit start-stop operation not only causes load deviation due to calculation deviation or untimely start-stop, but also causes great work pressure to the operation personnel, which has a negative impact on the safe and stable operation of the power station. SUMMARY

[0003] To solve the above technical problems, the present application provides a generator set start-stop auxiliary decision-making method based on minimum operation principle. Through the analysis of the unit start-stop process, the theoretical optimal start-stop number under the actual complex production condition is studied, and then the start-stop auxiliary decision-making method is proposed. The intelligent reminder is issued before the start-stop operation is needed, the priority reference is provided for the selection of start-stop unit, the start-stop auxiliary decision-making is provided for the operation personnel, the operation risk is reduced, the work efficiency is improved, and the work burden is reduced.

[0004] In order to realize the above technical features, the purpose of the present application is realized as follows: a generator set start-stop auxiliary decision-making method based on minimum operation principle, through the analysis of the unit start-stop process of hydropower station, combined with water head, unit vibration zone and load curve, based on the minimum start-stop operation principle, the theoretical optimal start-stop number at different time under the actual complex production condition is studied, the intelligent guidance and early warning of start-stop operation are realized, and the priority selection of start-stop is provided according to the unit operation state data and artificial priority setting.

[0005] A generator set start-stop auxiliary decision-making method based on minimum operation principle, comprising the following specific steps:

[0006] Step one, real-time unit state data acquisition;

[0007] Step two, data validity verification;

[0008] If the load data validity verification passes, go to step three, otherwise, the load data is not in the operational area alarm;

[0009] Step three, load data processing;

[0010] Step four, load data trend judgment at a certain time;

[0011] Step five, optimal number of operating units based on the principle of least action;

[0012] Step six, start-stop priority judgment;

[0013] Step seven, intelligent start-stop early warning.

[0014] The specific operation of step one is: through the computer monitoring system AGC of the hydropower station, the current water regime of the unit, the unit capacity and the vibration zone, the computer unit current output range, the adjustable capacity interval of the whole plant is calculated, the current head output range of the single unit, the adjustable capacity interval of the whole plant, the number of units in operation, the daily dispatching plan load curve, the unit operation state data of the whole plant are collected to the server through data communication.

[0015] The specific process of data validity verification in step two is: checking the validity of the planned load at each time, p min ≤p(x)≤p max *N max If the value is valid, otherwise, the value is invalid, where p(x) is the load value at a certain time, p min is the upper limit of the single unit vibration zone under the current water head, p max is the output limit of the single unit under the current water head, N max is the number of operating units in the power station, if p(x) > p max *N max or p(x) < p min , the value is invalid, an alarm is issued.

[0016] The specific process of load data processing in step three is: the dispatcher issues daily planned load to the hydropower plant according to the load condition, usually the planned load curve is issued with 5 minutes as a point, 288 load points for 24 hours a day, save these 288 points to the server database, and use two-point interpolation method to calculate the load per minute, so the load per minute is expressed as follows:

[0017]

[0018] In the formula, p(x) is a load value at a certain time, (x0, y0) and (x1, y1) are two adjacent dispatch load points at x time.

[0019] The specific process of the step four of the load data trend judgment at a certain time is as follows: since there are three states of a same load value, i.e. keeping unchanged, load increasing process and load decreasing process, the operation is different under different states of a same load, if p(x) = N*p min , in the formula, N is the current time unit operation quantity, in the state of keeping unchanged or increasing load, the unit does not need to be started or stopped, in the load decreasing process, the unit needs to be stopped; therefore, the trend judgment of the value p(x) at a certain time is needed to find the 5-minute load points (x t , y t ) and (x t+5 , y t+5 ) near x time, if y t ≤ p(x) < y t+5 and y t < y t+5 , the trend at x time is increasing load, if y t+5 < p(x) ≤ y t and y t < y t+5 , the trend at x time is decreasing load, if y t = p(x) = y t+5 , the trend at x time is stable state, through the trend analysis, each time point has a unique state, in the formula, x t and x t+5 are time points near x time, y t and y t+5 are the dispatch load values at x t and x t+5 .

[0020] The specific process of the step five of the theoretical optimal operation unit quantity based on the least operation principle is as follows: the theoretical optimal start quantity under different loads at each time is calculated based on the least operation principle, the trend of each time point can be determined according to the load point trend analysis, the optimal start quantity at each time under different trends is calculated; assuming that the current time unit operation quantity is N, in the trend of increasing load or stable state at x time, the theoretical optimal start quantity Nx at x time is calculated as follows:

[0021] When (N-1)*p max < p(x) ≤ N*p max , the theoretical optimal start quantity Nx at x time is Nx = N, otherwise, the judgment

[0022] When 0 < p(x) ≤ p max , the theoretical optimal start quantity at x time is Nx = 1.

[0023] When p max <p(x)≤2*p max At time x, the theoretically optimal number of machines to be started is Nx = 2, and so on;

[0024] When N*p max <p(x)≤(N+1)*p max At time x, the theoretically optimal number of machines to be started is Nx = N+1;

[0025] When (N+1)*p max <p(x)≤(N+2)*p max At time x, the theoretically optimal number of machines to be started is Nx = N + 2, and so on.

[0026] If the trend at time x is load reduction, then the theoretically optimal number of units to be started at time x is calculated as follows:

[0027] When N*p min ≤p(x)≤N*p max If the theoretically optimal number of machines to be started at time x is Nx = N, then p(x) < N*p. min When, if p min ≤p(x)<2*p min At time x, the theoretically optimal number of machines to be started is Nx = 1;

[0028] If 2*p min ≤p(x)<3*p min At time x, the theoretically optimal number of machines to be started is Nx = 2, and so on;

[0029] When p(x) > N*p max When N*p max <p(x)≤(N+1)*p max The theoretically optimal number of machines to be started at time x is Nx = N+1;

[0030] If N*p max <p(x)≤(N+1)*p max At time x, the theoretically optimal number of machines to be started is Nx = N+2, and so on.

[0031] The specific process for determining the start-up and shutdown priority in step six is ​​as follows: Long-term operation or long-term shutdown of the hydro-generator unit will have an adverse effect on the unit equipment. Therefore, the start-up and shutdown selection of the unit is based on the unit's operating status, and the computer automatically prioritizes the start-up and shutdown. At the same time, it can also provide manual priority settings according to complex production environments. The priority of the start-up and shutdown selection of the unit is determined by a comprehensive calculation of the combination of manual priority and automatic priority.

[0032] In the automatic priority calculation, the unit operation state data is collected, three states of unit grid-connected operation and shutdown standby, maintenance are set, the unit GCB position signal and the unit maintenance mark are taken as the criteria, when the unit GCB position signal is 1 and the unit GCB split signal is 0, the unit is judged to be in the grid-connected operation state, and the grid-connected operation time is started to be accumulated, when the unit GCB position signal is 0 and the unit GCB split signal is 1, the unit is judged to be in the shutdown standby state, and the shutdown standby time is accumulated; the longer the unit standby time is, the higher the automatic start priority of the unit is, the longer the unit shutdown standby time is, the higher the automatic shutdown priority of the unit is;

[0033] The manual start-stop priority judgment method is manually set by running the shift personnel to input the manual priority enabling flag, and the manual priority value of each unit is set to determine the manual priority setting in the start-stop selection.

[0034] The specific process of the start-stop intelligent early warning in the step seven is that the optimal start number of units at each moment is determined according to the minimum operation principle, when the theoretical optimal running unit number Nx under the load at a future moment is inconsistent with the current start number N, it is judged that start-stop operation is needed, when Nx>N, it is judged that start operation is needed at the moment x, and the start number is Nx-N, when Nx<N, it is judged that stop operation is needed, and the start number at the moment x is Nx-N, the optimal unit running number at each moment is calculated through program operation, and a briefing and voice alarm are issued in the monitoring system before the start-stop operation is needed, and the running picture is displayed, so as to provide auxiliary decision for the running shift personnel.

[0035] The present application has the following beneficial effects:

[0036] 1. The present application determines the unique load trend at any moment point through the trend analysis of the load at each negative moment point of the dispatching plan load curve, so as to complete the calculation of the theoretical optimal unit start number at each moment based on the minimum operation principle, determine the optimal unit running number at each moment, and complete the auxiliary decision of the start-stop operation through the comparison of the optimal start number at a future moment and the current unit running number.

[0037] 2. The present application provides the unit start-stop priority selection, determines the priority in the unit start-stop selection through the comprehensive calculation of the automatic priority and the manual priority, improves the scientificity of the unit operation and maintenance control, and is beneficial to improving the healthy and stable operation of the unit equipment.

[0038] 3. Compared with the method of relying on manual real-time attention to load changes and then performing unit start-stop operation judgment, the present application judges the start-stop operation through program logic operation, greatly reduces the workload of the running shift personnel, and liberates the labor force.

[0039] 4. The implementation of the start-up and shutdown auxiliary decision-making function of this invention replaces manual judgment with rigorous program logic calculation, reduces the risk of calculation error, and improves the level of power plant control intelligence. Attached Figure Description

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0041] Figure 1 This is a flowchart of the calculation of the optimal number of machines to be started based on the principle of minimum operation in this invention.

[0042] Figure 2 This invention provides a start / stop auxiliary decision-making process.

[0043] Figure 3 This is the present invention. Figure 1 Partial view of steps one through four.

[0044] Figure 4 This is the present invention. Figure 1 Local flowcharts for the steady or rising states.

[0045] Figure 5 This is the present invention. Figure 1 A partial flowchart of the descent state. Detailed Implementation

[0046] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0047] Example 1:

[0048] See Figures 1-5 A generator set start-up and shutdown auxiliary decision-making method based on the principle of minimum operation includes the following steps:

[0049] Step 1: Determine the key parameters for start-up and shutdown auxiliary decision-making. Based on the decision-making process of manual start-up and shutdown operations, determine the vibration zone of the unit under the current head, the number of units currently connected to the grid, the number of units that can be started in the whole plant, and the load value of 288 points in the daily scheduling plan as key parameters, and collect the data to the server through communication.

[0050] Step 2: Verify the validity of the collected data to prevent errors in the calculated data due to incorrect data collection. Check the validity of the planned load at each time point, p min ≤p(t)≤p max *N max The set value is valid if the set value is valid, otherwise the set value is invalid. In the formula, p(t) is the load value at each time point of the 288-point scheduling plan. Taking a single vibration zone as an example, p min p is the upper edge of the vibration zone of a single unit under the current head. max Given the current head and single-unit output limitations, N maxFor the number of grid-connected units of power station, if p(t) > p max *N max or p(t) < p min , set the value invalid, issue an alarm that the planned load is not in the operable range, stop operation, and return to step one;

[0051] Step three: To ensure the real-time performance of the start-stop auxiliary decision function, the 288-point planned load issued by the dispatch is converted into per-minute load values, and a two-point interpolation method is used to calculate the per-minute load. Therefore, the per-minute load can be expressed as follows:

[0052]

[0053] In the formula, p(x) is the load value at any time between x0 and x1, and (x0, y0) and (x1, y1) are the adjacent two load points at x time;

[0054] Step four: Based on the principle of minimum operation, the theoretical optimal number of operating units at future times is calculated. The number of operating units at the current time is N, and the trend at x time is increasing load or steady state. The calculation method of the theoretical optimal number of operating units at x time is as follows:

[0055] S1: If (N-1) * p max < N * p max , the optimal number of operating units Nx at x time is N, no start-stop operation is needed, and the process returns to step one, otherwise, S2 is entered;

[0056] S2: If p(x) ≤ (N-1) * p max , S3 is entered, otherwise, S5 is entered;

[0057] S3: If 0 < p(x) ≤ p max , the optimal number of operating units Nx at x time is 1, step five is entered, otherwise, S4 is entered;

[0058] S4: If p max < 2 * p max , the optimal number of operating units Nx at x time is 2, step five is entered, otherwise, the next step is judged, and so on, until the optimal number of operating units under the condition of increasing load or steady state is calculated when p(x) ≤ (N-1) * p max .

[0059] S5: If p(x) > N * p max , S6 is entered, otherwise, the planned value change is judged and the process returns to S1;

[0060] S6: If p(x) ≤ (N+1) * p max , the optimal number of operating units Nx at x time is N+1, step five is entered, otherwise, S7 is entered;

[0061] S7: If p(x)≤(N+2)*p max , then the optimal number of units Nx= N+2 at time x, go to step five, otherwise go to the next judgment, and so on, until the optimal number of units is calculated when p(x)>N*p max in the case of load increase or stable state;

[0062] If the trend at time x is load reduction, then the theoretical optimal number of units at time x is calculated as follows:

[0063] S1: Calculate the optimal number of units in the load reduction state, if N*p min ≤ p(x)≤ N*p max , then the optimal number of units Nx= N at time x, no need to start and stop operation, return to step one, otherwise go to S2;

[0064] S2: If p(x)>N*p max , go to S3, otherwise go to S5;

[0065] S3: If p(x)≤(N+1)*p max , then the optimal number of units Nx= N+1 at time x, go to step five, otherwise go to S4;

[0066] S4: If p(x)≤(N+2)*p max , then the optimal number of units Nx= N+2 at time x, go to step five, otherwise go to the next judgment, until the optimal number of units is calculated when p(x)>N*p max in the case of load reduction;

[0067] S5: If p(x)<N*p min , go to S6, otherwise go to S1 to judge the change of the planned value;

[0068] S6: If p min ≤ p(x)<2*p min , then the optimal number of units Nx= 1 at time x, go to step five, otherwise go to S7;

[0069] S7: If 2*p min ≤ p(x)<3*p min , then the optimal number of units Nx= 2 at time x, go to step five, otherwise go to the next judgment, until the optimal number of units is calculated when p(x)<N*p min in the case of load reduction;

[0070] Step five: start-stop priority calculation, calculate the automatic priority of stopping according to the running time of the unit, the longest running time has the highest priority of stopping, calculate the automatic priority of starting according to the standby time of the unit, the longer the standby time, the higher the priority of starting, if the manual priority mark is put in, the manual priority setting is given priority, and the priority calculation result is assigned to the unit in the non-maintenance state, and step six is entered;

[0071] Step six: intelligent start-stop reminder, when the current number of units N is the same as the optimal number of units Nx calculated at future x time, no start-stop operation is needed within x time, and step one is returned; when the optimal number of units Nx calculated at future x time is greater than N, it is judged that starting operation is needed at x time, and the starting number is Nx-N; when the optimal number of units Nx calculated at future x time is less than N, it is judged that stopping operation is needed at x time, and the stopping number is N-Nx; according to the priority result of the stopped unit, the system sends a pre-warning signal and a voice alarm, and prompts the start-stop time, number, and unit number, providing decision-making assistance for the operation personnel.

[0072] Embodiment 2:

[0073] Please refer to Figure 1 A generator unit start-stop auxiliary decision-making method based on the minimum operation principle:

[0074] S1: Real-time unit state data acquisition: dispatch load plan curve load point, unit output limit and vibration zone under current water head, input maintenance marked unit, unit running / standby state, current number of started units, enter S2;

[0075] S2: Data validity test, check if the load data is in the operable area, if the data is valid, enter S3, otherwise send an alarm signal and the process is exited;

[0076] S3: Data processing, calculate the load value of each minute according to the dispatch plan load curve by using the interpolation method, calculate the standby / running time of the unit, set the start-stop auxiliary decision-making warning time, and enter S4;

[0077] S4: Trend judgment, determine the unique trend state corresponding to each time point by analyzing the trend of each load point, and determine the optimal starting number according to different trends, when the load trend is increasing or stable, enter S5, otherwise enter S14;

[0078] S5: Optimal running number calculation under increasing load or stable state, if (N-1)*p max <p(x)≤N*p max , then x

[0079] optimal starting number Nx=N at time, enter S23, otherwise enter S6;

[0080] S6: If p(x)≤(N-1)p max If the condition is met, proceed to S7; otherwise, proceed to S10.

[0081] S7: If 0 < p(x) ≤ p max If the optimal number of machines to be turned on at time x is Nx = 1, proceed to S23; otherwise, proceed to S8.

[0082] S8: If p max <p(x)≤2*p max If the optimal number of units to be started at time x is Nx = 2, proceed to S23; otherwise, proceed to the next step. This process continues until it is calculated that p(x) ≤ (N-1)p under increased load or steady-state conditions. max Optimal number of operating units at the time;

[0083] S9: If (N-2)*p max <p(x)≤(N-1)*p max Then the optimal number of machines to be started at time x is Nx = N-1, and proceed to S23;

[0084] S10: If p(x) > N*p max If the plan value changes, proceed to S11; otherwise, check for changes in the planned value and return to S4.

[0085] S11: If p(x)≤(N+1)*p max If the optimal number of machines to be turned on at time x is Nx = N+1, proceed to S23; otherwise, proceed to S12.

[0086] S12: If p(x)≤(N+2)*p max If the optimal number of units to be started at time x is Nx = N + 2, proceed to S23. Otherwise, continue the process for the next judgment until it is calculated that p(x) > N*p under the conditions of increased load or steady state. max Optimal number of operating units at the time;

[0087] S13: If (N) max -1)*p max <p(x)≤N max *p max Then the optimal number of machines to be started at time x is Nx = Nmax, proceed to S23;

[0088] S14: Calculation of optimal operating parameters for the unit under reduced load conditions, if N*p min ≤p(x)≤N*p max If the optimal number of machines to be turned on at time x is Nx = N, proceed to S23; otherwise, proceed to S15.

[0089] S15: If p(x) > N*p maxIf yes, go to S16, otherwise go to S19;

[0090] S16: If p(x)≤(N+1)*p max , then the optimal number of units Nx= N+1 at x moment, go to S23, otherwise go to S17;

[0091] S17: If p(x)≤(N+2)*p max , then the optimal number of units Nx= N+2 at x moment, go to S23, otherwise go to the next judgment until the optimal number of units under the reduced load state is calculated when p(x) > N*p max ;

[0092] S18: If (N max -1)*p max < p(x)≤N max *p max , then the optimal number of units Nx= Nmax at x moment, go to S23;

[0093] S19: If p(x) < N*p min , go to S20, otherwise go to S4 to judge the change of the planned value;

[0094] S20: If p min ≤p(x) < 2*p min , then the optimal number of units Nx= 1 at x moment, go to S23, otherwise go to S21;

[0095] S21: If 2*p min ≤p(x) < 3*p min , then the optimal number of units Nx= 2 at x moment, go to S23, otherwise go to the next judgment until the optimal number of units under the reduced load state is calculated when p(x) < N*p min ;

[0096] S22: If (N-1)*p min ≤p(x) < N*p min , then the optimal number of units Nx= N-1 at x moment, go to S23;

[0097] S23: Automatic priority calculation, calculate the automatic priority of the units according to the running time, the longest running time has the highest priority, the longest standby time has the highest priority, calculate the automatic priority of the units and assign the calculation result to the automatic priority sequence number of the non-maintenance state units, go to S24;

[0098] S24: Judge whether the manual priority flag is put in, if yes, go to S25, if no, go to S26;

[0099] S25: manual priority calculation, calculate the priority of the start-stop unit according to the manual priority setting of the operator on duty, and assign the manual priority calculation result to the non-maintenance state unit to enter S26;

[0100] S26: start-stop decision judgment, when the number of currently running units is equal to the number of optimal running units calculated at future time x, no start-stop operation is needed at time x, and the process returns to S1. When the number of optimal running units calculated at future time x is Nx>N, it is judged that start operation is needed at time x, and the process enters S27. When the number of optimal running units calculated at future time x is Nx<N, it is judged that stop operation is needed at time x, and the process enters S28;

[0101] S27: according to the priority marking of the start unit, an early warning signal of start is issued, and the optimal number of units running at time x and the unit number needing start operation are displayed, and the process returns to S1;

[0102] S28: according to the priority marking of the stop unit, an early warning signal of stop is issued, and the optimal number of units running at time x and the unit number needing stop operation are displayed, and the process returns to S1.

Claims

1. A method for assisting decision of start-stop of a generator set based on a principle of minimum start-stop operation, characterized in that, Through the analysis of the water and electricity station unit start-stop process, combined with the water head, unit vibration area, load curve, based on the minimum start-stop operation principle, the theoretical optimal start-stop number at different times under actual complex production conditions is studied, the intelligent guidance and early warning of start-stop operation are realized, and the priority selection of start-stop is provided according to the unit operation state data and artificial priority setting; Comprise the following specific steps: Step one, real-time unit state data acquisition; Step two, data validity verification; If the load data validity verification passes, it enters step three, otherwise the load data is not in the running area alarm; Step three, load data processing; Step four, load data trend judgment at a certain time; Step five, the theoretical optimal number of running units based on the minimum start-stop operation principle; Based on the minimum start-stop operation principle, the theoretical optimal number of start-ups at different loads at each time is calculated, and the trend of each time point can be determined according to the load point trend analysis, and the optimal number of start-ups at each time under different trends is calculated. Step six, start-stop priority judgment; Step seven, start-stop intelligent early warning.

2. The method of claim 1, wherein the method is based on the principle of minimum start-stop operation. The specific operation of step one is: through the water power station computer monitoring system AGC, according to the current water regime of the unit, the unit capacity and the vibration area, the computer calculates the current output range of the unit, and the adjustable capacity interval of the whole plant is calculated, the current water head output range of the single unit, the adjustable capacity interval of the whole plant, the number of running units, the daily dispatching plan load curve, and the unit operation state data are collected to the server through data communication.

3. The method of claim 1, wherein the method is characterized by: The specific process of the data validity check in the second step is checking the validity of the planning load at each time, , the value is valid, otherwise the value is invalid, wherein is the load value at a certain time, is the upper limit of the vibration zone of the single unit under the current water head, is the output limit of the single unit under the current water head, is the number of operable units of the power station, if or , the value is invalid, and an alarm is issued.

4. The method of claim 3, wherein the method is characterized by: The specific process of load data processing in step three is: the dispatcher issues daily plan load according to the load to the hydroelectric power plant, usually issues a plan load curve with 5 minutes as a point, 288 load points for 24 hours, saves the 288 load points to the server database, and uses two-point interpolation method to calculate the load per minute, so the load per minute is expressed as follows: （1） In the formula, is the load value at a certain time, respectively x time adjacent two dispatch load point.

5. The method for assisting decision of start-stop of a generator set based on the principle of minimum start-stop according to claim 4, characterized in that, The specific process for judging the load data trend at a certain moment in step four is as follows: Since the same load value has three states—remaining unchanged, load increasing, and load decreasing—the operation differs depending on the state of the same load. In the formula, N represents the number of units operating at the current time. When the load remains constant or increases, the units do not require start-up or shutdown operations. However, during load reduction, shutdown operations are required. Therefore, it is necessary to introduce the load value at a certain moment. Based on trend analysis, identify the 5-minute load point around time x. ,like and If the trend at time x is increasing load, then... and If the trend at time x is a decrease in load, then... If the trend at time x is a steady state, then trend analysis shows that each time point has a unique and definite state, as shown in the formula. and Let x be a time point near time x. and for and The load value is issued at the corresponding time.

6. The method of claim 5, wherein the method is based on the principle of minimum start-stop operation. The specific process of the theoretical optimal number of running units based on the minimum start-stop operation principle in step five is: assuming that the number of units running at the current time is N, and the trend at x time is increasing load or steady state, then the calculation method of the theoretical optimal number of start-ups Nx at x time is as follows: When x is the time point, Nx is the theoretical optimal start-up number at the time point x, N is the theoretical optimal start-up number at the time point x, and otherwise, the judgment When the theoretical optimal start quantity at time x is Nx=1; When the theoretical optimal start quantity at time x is Nx=2, and so on. When the time x, the theoretical optimal start quantity Nx=N+1; When x is the time, the theoretical optimal start quantity Nx=N+2 at this time, and so on. If the trend at x time is decreasing load, then the calculation method of the theoretical optimal number of start-ups at x time is as follows: When the x-th moment theoretical optimal start quantity Nx=N, otherwise judge When the x-th moment theoretical optimal start quantity Nx=1; If At time x, the theoretical optimal start quantity Nx=2, and so on. When , if , the theoretical optimal start quantity Nx at time x is Nx=N+1; If At time x, the theoretical optimal number of start-ups Nx= N+2, and so on.

7. The method of claim 1, wherein the method is based on the principle of minimum start-stop operation. The specific process of start-stop priority judgment in step six is: long-time operation or long-time shutdown of hydroelectric generator set will cause adverse effects on the unit equipment, therefore, according to the unit operation state, the automatic priority of unit start and stop is calculated, and the artificial priority setting is provided according to the complex production environment, the priority of unit start and stop is calculated and judged by combining artificial priority and automatic priority; In the automatic priority calculation, the unit operation state data is collected, and three states of unit grid-connected operation and shutdown standby, and maintenance are set. The GCB position signal and the unit maintenance flag are used as the criterion. When the GCB position signal is 1 and the split signal is 0, it is judged that the unit is in the grid-connected operation state, and the grid-connected operation time is started to be counted. When the GCB position signal is 0 and the split signal is 1, it is judged that the unit is in the shutdown standby state, and the shutdown standby time is accumulated. The longer the unit shutdown standby time is, the higher the automatic start priority of the unit is, and the longer the unit grid-connected operation time is, the higher the automatic shutdown priority of the unit is. The manual start-stop priority judgment method is manually set by an operation attendant after inputting a manual priority enabling flag, and the manual priority value of each unit is set to determine the manual priority, thereby providing manual priority setting in the start-stop selection.

8. The method of claim 1, wherein the method is based on the principle of minimum start-stop operation. The specific process of the intelligent start-stop warning in step seven is as follows: the optimal start quantity of each time is determined according to the principle of minimum start-stop operation, and when the theoretical optimal start quantity Nx under the load at a future time is inconsistent with the current unit operation quantity N, it is judged that start-stop operation is needed. When Nx>N, it is judged that start operation is needed at x time, and the start quantity is Nx-N. When Nx<N, it is judged that stop operation is needed, and the start quantity at x time is Nx-N. The optimal unit operation quantity at each time is calculated through program operation, a briefing and voice alarm are issued in the monitoring system before the start-stop operation is needed, and the operation picture is displayed, thereby providing auxiliary decision-making for the operation attendant.

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