A method for power station AGC to cross vibration zone

Abstract

The present application proposes a method for a power station AGC to cross a vibration zone, which relates to the field of power station load adjustment. The method includes: when the power station meets the priority down-crossing input conditions, the priority down-crossing function is turned on, and according to the load curve, a strategy of not crossing the vibration zone if it can be avoided is adopted, and when the power station meets the priority down-crossing exit conditions, the priority down-crossing function is turned off; according to the unit shutdown needs, when the power station meets the immediate down-crossing pressure plate input conditions, the immediate down-crossing pressure plate is put into operation, and according to the current load, a strategy of crossing the vibration zone if it can be crossed is adopted, and when the power station meets the immediate down-crossing exit conditions, the immediate down-crossing pressure plate is exited; when the power station meets the automatic up-crossing input conditions, the automatic up-crossing function is turned on, and according to the current load, a strategy of crossing the vibration zone if it can be crossed is adopted, and when the power station meets the automatic up-crossing exit conditions, the automatic up-crossing function is turned off. The method proposed in the present application can improve the AGC input rate and the automation level of the power plant.

Description

Technical Field

[0001] The present application relates to the field of power station load adjustment, and in particular to a method for an AGC of a power station to cross a vibration zone. Background Art

[0002] Since the implementation of the frequency regulation auxiliary service market, there have been more stringent requirements on the start and stop times of centralized control units. Since the general dispatching requires that the power plant units should, in principle, automatically cross the vibration zone, if they are manually crossed, they should exit the AGC operation of the entire plant. Start and shutdown operations are basic operations that do not necessarily need to be performed manually, which take up a lot of time, and manual operations are not as accurate as automatic adjustments by the monitoring system.

[0003] During the start-up and shutdown process of a power station unit, the load is manually adjusted to pass through the unit vibration zone. The number of setting times is large, the duration is long, the adjustment accuracy is low, and it is easy to cause short-term load deviation. The method of manually adjusting the unit load to control the unit through the vibration zone is not only difficult to achieve the level of AGC automatic adjustment in load adjustment accuracy, which is easy to cause load deviation. In addition, before each unit start-up and shutdown plan, the operator must calculate the load and time point assigned by the AGC each time according to the load change range in advance, and then manually adjust the load of each unit on the monitoring system according to the time point, which increases the risk of operators setting values ​​incorrectly and the workload, which is extremely detrimental to the safe and stable operation of the power station and the system. Summary of the invention

[0004] In view of the above problems, a method for power station AGC to cross the vibration zone is proposed. Through the analysis of the load adjustment process of start-up and shutdown and combined with relevant constraints, the load is quickly adjusted through AGC automatic control to achieve the purpose of quickly crossing the vibration zone.

[0005] The scheme of this application is as follows:

[0006] A method for a power station AGC to cross a vibration zone, comprising:

[0007] When the power station meets the priority down-passing input conditions, the priority down-passing function is turned on, and according to the load curve, a strategy of not passing through the vibration zone is adopted if it is not necessary to pass through, and when the power station meets the priority down-passing exit conditions, the priority down-passing function is turned off;

[0008] According to the unit shutdown needs, when the power station meets the immediate down-through pressure plate input conditions, the immediate down-through pressure plate is put into use, and according to the current load, the strategy of down-through the vibration zone is adopted if it can be down-through, and when the power station meets the immediate down-through exit conditions, the immediate down-through pressure plate is exited;

[0009] When the power station meets the automatic crossing input conditions, the automatic crossing function is turned on, and according to the current load, the strategy of crossing the vibration zone if possible is adopted, and when the power station meets the automatic crossing exit conditions, the automatic crossing function is turned off.

[0010] Optionally, the priority down-through input condition is that the whole plant AGC is in operation and the immediate down-through pressure plate is not in operation;

[0011] The priority down-through exit condition is that when the immediate down-through pressure plate is not put into operation, the whole plant AGC exits.

[0012] Optionally, the priority down-passing function is enabled, and according to the load curve, a strategy of not passing through the vibration zone is adopted if possible, and when the power station meets the priority down-passing exit condition, the priority down-passing function is disabled, including:

[0013] Synchronously adjust the load of all units to the upper edge of the vibration zone through AGC;

[0014] When the total unit has a reduction margin but the reduction margin cannot meet the load requirements or the total unit has no reduction margin, the unit with the highest priority is selected to pass through the vibration zone to the base load;

[0015] Automatically exit the single-machine AGC, and the AVC program will reduce the reactive power of the downstream unit to within the allowable shutdown range, and the reactive power of the remaining units will synchronously match the reactive power adjustment amount of the downstream unit. After the adjustment is completed, exit the single-machine AVC, and the priority downstream function of the unit with the highest priority will exit.

[0016] Optionally, the method further includes:

[0017] When the total unit has a reduction margin and the adjustment margin can meet the load requirements, the load of each unit is adjusted according to priority, provided that no unit passes through the vibration zone.

[0018] Optionally, the condition for immediately putting the pressure plate into operation is that the whole plant AGC is put into operation;

[0019] The immediate exit condition of the pressure plate is that a unit completes the exit to base load and automatically exits or the whole plant AGC exits.

[0020] Optionally, the immediate penetration pressure plate is put into use, and according to the current load, a strategy of passing through the vibration zone if possible is adopted, and when the power station meets the immediate penetration exit condition, the immediate penetration pressure plate is exited, including:

[0021] Set the priority of the shutdown unit to the highest and put the immediate down-load pressure plate into operation, and use AGC to detect whether the adjustment capacity of other units meets the requirement for the shutdown unit to down-load to base load;

[0022] If the regulating capacity of other units meets the requirement of the shutdown unit to pass through the base load, the shutdown unit will be immediately reduced to pass through the vibration zone to the base load, and other units will be adjusted up in turn, among which the unit with the lowest load will be given priority to match and increase;

[0023] When the shut down unit passes through the base load, the single-unit AGC and the pressure plate are automatically exited, and the AVC program completes the reduction of the shut down unit's reactive power to within the allowable shutdown range. The reactive power of the remaining units synchronously matches the reactive power adjustment amount of the unit. After the adjustment is completed, the single-unit AVC is exited.

[0024] Optionally, the method further includes:

[0025] If the regulating capacity of other units does not meet the requirement for the shutdown unit to pass down to base load, all units will normally execute the plant-wide AGC allocation strategy, and the plant load will be reduced until the regulating capacity of other units meets the requirement for the shutdown unit to pass down to base load;

[0026] When the regulation capacity of other units meets the requirement that the shut-down unit can be reduced to base load, a margin threshold is set.

[0027] Optionally, the automatic upper penetration input condition is that the whole plant AGC is put into operation and a single unit AGC of a unit running with base load is put into operation;

[0028] The automatic crossing exit condition is that the whole plant AGC exits or a unit automatically adjusts to be consistent with the load of other AGC units after crossing the vibration zone, or a single unit AGC of a unit operating with base load exits.

[0029] Optionally, the automatic crossing function is enabled, and according to the current load, a strategy of crossing the vibration zone if possible is adopted, and when the power station meets the automatic crossing exit condition, the automatic crossing function is disabled, including:

[0030] For grid-connected units with base load, the automatic up-through function takes effect automatically after AGC is put into operation;

[0031] The current load is calculated by AGC, and it is determined whether the current load satisfies the grid-connected unit with base load to pass through the stable operation zone and does not cause other units to pass through the vibration zone;

[0032] If the current load satisfies the grid-connected base-load unit to cross over to the stable operation zone, the AGC automatically adjusts the active power of the grid-connected base-load unit to be consistent with other units. After the adjustment is completed, the automatic crossing function of the grid-connected base-load unit ends.

[0033] Optionally, the method further includes:

[0034] If the current load does not satisfy the grid-connected base-load unit to cross over to the stable operation zone, the grid-connected base-load unit will keep the AGC in operation and wait until the current load at a certain moment satisfies the grid-connected base-load unit to cross over to the stable operation zone.

[0035] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0036] By analyzing the load adjustment process of startup and shutdown and combining relevant constraints, the load can be quickly adjusted through AGC automatic control to achieve the purpose of quickly crossing the vibration zone, which can improve the AGC investment rate and the automation level of the power plant.

[0037] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0039] Figure 1 It is a flow chart of a method for a power station AGC to cross a vibration zone according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0041] Figure 1 The flowchart of a method for a power station AGC to cross a vibration zone according to an embodiment of the present application includes:

[0042] Step 101, when the power station meets the priority down-through input conditions, the priority down-through function is turned on, and according to the load curve, a strategy of not going through the vibration zone if possible is adopted, and when the power station meets the priority down-through exit conditions, the priority down-through function is turned off.

[0043] At present, the unit has a manual down-going function, but does not have a down-going waiting function, and does not distinguish between priority down-going and immediate down-going functions. The down-going vibration zone function is completed by manual instructions issued by the operating personnel, so it is necessary to add priority down-going and immediate down-going functions to improve the AGC commissioning rate, and the down-going vibration zone function is completed by the program automatically.

[0044] In the embodiment of the present application, when the AGC of the entire plant is put into operation and the immediate down-through pressure plate is not put into operation, the priority down-through function is turned on.

[0045] The priority down-through function process is as follows:

[0046] (1) Synchronously adjust the load of all units to the upper edge of the vibration zone through AGC;

[0047] (2) When the total unit has a reduction margin but the reduction margin cannot meet the load requirements or the total unit has no reduction margin, the unit with the highest priority is selected to pass through the vibration zone to the base load.

[0048] (3) Automatically exit the single-machine AGC. The AVC program will reduce the reactive power of the downstream unit to within the allowable shutdown range, and the reactive power of the remaining units will synchronously match the reactive power adjustment amount of the downstream unit. After the adjustment is completed, the single-machine AVC will be exited, and the priority downstream function of the unit with the highest priority will be exited.

[0049] It should be noted that the units with the highest priority should be selected to pass through the vibration zone to the base load, and in principle, they should be adjusted one-to-one.

[0050] In addition, an adjustment margin threshold should be set when the unit is down-passing.

[0051] In one possible embodiment, when P 总 <n*120MW+P 未投实发 +20MW, the unit with the highest priority passes through the vibration zone to the base load and automatically exits the single-machine AGC and single-machine AVC, where n is the number of AGC units put into operation, 20MW is the regulation margin threshold, and 120MW is the upper limit of the vibration zone.

[0052] In addition, when the total unit has a reduction margin and the adjustment margin can meet the load requirements, the load of each unit is adjusted according to priority, provided that no unit passes through the vibration zone.

[0053] In a possible embodiment, the AVC program reduces the reactive power of the unit to within the allowable shutdown range (±6Mvar), and the reactive power of other units synchronously matches the reactive power adjustment amount of the unit. In principle, the matching process adopts a one-to-one adjustment with an adjustment step of 5MVar to avoid reactive power fluctuations. After the adjustment is completed, the single-machine AVC is exited.

[0054] In addition, it should be noted that the priority down-through function has the following precautions:

[0055] (1) Only when it is necessary to pass through the vibration zone, the units with higher priority will be given priority to pass through, and in other periods, they will participate in the AGC regulation of the whole plant normally;

[0056] (2) When a unit passes through the vibration zone first, it is not allowed to cause other units to pass through the vibration zone for matching.

[0057] (3) Priority is given to the down-crossing function. After the unit with the highest priority crosses down to base load and exits the single-unit AGC, if the single-unit AGC of the unit is put into operation again, the up-crossing vibration zone adjustment is performed according to the up-crossing vibration zone strategy.

[0058] In a possible embodiment, units 1, 2, and 3 are in operation, the priority of unit 1 is "1", the total load is 390MW, and the active power target value of the whole plant at the next moment is 350MW, then unit 1 is downgraded to 20MW and exits the AGC of unit 1. The specific parameters are shown in Table 1.

[0059]

[0060]

[0061] Table 1

[0062] Step 102, according to the unit shutdown needs, when the power station meets the conditions for immediately putting the pressure plate into operation, put the pressure plate into operation, and according to the current load, adopt the strategy of going through the vibration zone if possible, and when the power station meets the conditions for exiting the pressure plate, exit the pressure plate.

[0063] In the embodiment of the present application, when the unit needs to be shut down for troubleshooting, for example, when it is manually determined that the unit needs to be shut down, or when the unit needs to be shut down for reasons such as fault handling, and the entire plant AGC is put into operation, the pressure plate is immediately lowered.

[0064] The immediate down-through function process is as follows:

[0065] (1) Set the priority of the shutdown unit to the highest and put it into immediate down-load pressure plate, and use AGC to detect whether the adjustment capacity of other units can meet the down-load of the shutdown unit to base load;

[0066] (2) If the regulating capacity of other units meets the requirement of the shutdown unit to pass through the base load, the shutdown unit will be immediately reduced to pass through the vibration zone to the base load, and other units will be adjusted up in turn to match. In principle, the adjustment is one-to-one, and the unit with the lowest load will be given priority to match the increase;

[0067] (3) When the shutdown unit passes through the base load, the single-unit AGC is automatically exited and the pressure plate is immediately passed. The AVC program completes the reduction of the shutdown unit's reactive power to within the allowable shutdown range. The reactive power of the remaining units is synchronously matched with the reactive power adjustment amount of the unit. After the adjustment is completed, the single-unit AVC is exited.

[0068] In a possible embodiment, the AVC program is used to reduce the reactive power of the unit to within the allowable shutdown range (±6Mvar), and the reactive power of other units is synchronously matched with the reactive power adjustment amount of the unit. In principle, the matching process adopts a one-to-one adjustment with an adjustment step of 5Mvar.

[0069] In addition, if the regulating capacity of other units does not meet the requirements for the shutdown unit to pass down to the base load, all units will normally implement the plant-wide AGC allocation strategy, and the plant load will be reduced until the regulating capacity of other units meets the requirements for the shutdown unit to pass down to the base load;

[0070] When the regulation capacity of other units is sufficient to allow the shut-down unit to cross over to base load, a margin threshold is set.

[0071] In a possible embodiment, when the whole plant load is reduced to 500MW, it just meets the requirement of crossing the vibration zone, so the crossing should be started when the whole plant load is reduced to 480MW.

[0072] In one possible embodiment, when P 总 <(n-1)*350MW+P 未投实发 When the load is -20MW, the unit with the highest priority passes through the vibration zone to the base load, and automatically exits the single-machine AGC, single-machine AVC and immediately passes through the pressure plate, where n is the number of AGC units, 20MW is the adjustment margin threshold, and 350MW is the maximum load of each unit.

[0073] In addition, it should be noted that the immediate down-through function has the following precautions:

[0074] (1) When other units are matched and adjusted during the immediate down-through process, the units with base load should be selected for matching and adjustment first. During the load stable period, this process can complete the load replacement of the rotation units.

[0075] (2) Only when the immediate lower pressure plate is put into operation, are two units allowed to pass through the vibration zone (one up and one down) at the same time for matching adjustment.

[0076] (3) When the whole plant AGC mode is put into open-loop mode, it is allowed to put into operation immediately and penetrate the pressure plate. At this time, the load is only distributed but not executed.

[0077] In a possible embodiment, units 1, 2, and 3 are in operation, and the pressure plate is immediately put into operation. The priority of unit 1 is "1", the total load is 750MW, and the active power target value of the whole plant at the next moment is 670MW. Then unit 1 is downgraded to 20MW, and the AGC of unit 1 is exited and the pressure plate is immediately put into operation. The specific parameters are shown in Table 2.

[0078]

[0079] Table 2

[0080] Step 103, when the power station meets the automatic crossing input conditions, the automatic crossing function is turned on, and according to the current load, the strategy of crossing the vibration zone if possible is adopted, and when the power station meets the automatic crossing exit conditions, the automatic crossing function is turned off.

[0081] In the prior art, taking Unit 1 as an example, when the regulating capacity of other units cannot match, the "Unit 1 retreat / lock single unit AGC input" alarm signal will be reported, and the AGC of Unit 1 cannot be put into operation. When the regulating capacity of other units can match, the AGC of Unit 1 needs to be put into operation again, and the unit can be increased to 120MW. Therefore, this application proposes an automatic increase function to solve the above problem.

[0082] In the embodiment of the present application, when the AGC of the entire plant is put into operation and the AGC of a single unit of a base load operation unit is put into operation, the automatic wear-through function is turned on.

[0083] The automatic threading function process is as follows:

[0084] (1) For grid-connected units with base load, the automatic up-through function will take effect automatically after AGC is put into operation;

[0085] (2) Calculate the current load through AGC and determine whether the current load satisfies the grid-connected unit with base load to pass through the stable operation zone without causing other units to pass through the vibration zone;

[0086] (3) If the current load satisfies the grid-connected baseload unit to cross over to the stable operation zone, the AGC automatically adjusts the active power of the grid-connected baseload unit to be consistent with other units. After the adjustment is completed, the automatic crossover function of the grid-connected baseload unit ends. It should be noted that if the current load does not satisfy the grid-connected baseload unit to cross over to the stable operation zone, the grid-connected baseload unit maintains the AGC input state and waits until the current load at a certain moment satisfies the grid-connected baseload unit to cross over to the stable operation zone. It should also be noted that the automatic crossover function has the following precautions:

[0087] (1) When the conditions are met for the unit to automatically cross the vibration zone, a 20MW margin should be reserved to prevent the unit from crossing the vibration zone again due to frequency regulation and load reduction. For example, when the total plant load is increased to 500MW, the unit just crosses the vibration zone. In this case, the unit should not start crossing the vibration zone until the total plant load is increased to 520MW.

[0088] In one possible embodiment, when P 总 >n*120MW+P 未投实发 +20MW, the unit waiting to pass through the vibration zone and automatically adjust the active power to be consistent with other units, where n is the number of AGC units put into use and 20MW is the adjustment margin threshold.

[0089] (2) When multiple units are operating at base load, and the current load is only sufficient for one unit to pass through the vibration zone, the AGC should be able to automatically select the unit with the highest priority to pass through first.

[0090] (3) The automatic crossing of a unit is not allowed to cause other units to cross the vibration zone for matching.

[0091] (4) Only when the immediate lower pressure plate is put into operation and the automatic upper pressure plate is matched and adjusted, are the two units allowed to pass through the vibration zone (one up and one down) for matching adjustment at the same time.

[0092] In a possible embodiment, units 2 and 3 are in operation, and unit 1 is started up to base load, with a total load of 320MW. The next moment, the active power target value of the whole plant is 384MW, and unit 1 is increased to 128MW. The specific parameters are shown in Table 3.

[0093]

[0094] Table 3

[0095] It should also be noted that when the immediate downward penetration pressure plate is put into operation, the immediate downward penetration function is executed. If the immediate downward penetration pressure plate is not put into operation, the priority downward penetration function is executed. The immediate downward penetration pressure plate and the automatic upward penetration function can be used at the same time or separately.

[0096] The embodiment of the present application analyzes the start-up and shutdown load adjustment process, combines relevant constraints, and quickly adjusts the load through AGC automatic control to achieve the purpose of quickly crossing the vibration zone, which can improve the AGC investment rate and the automation level of the power plant.

[0097] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of this disclosure can be achieved, and this document is not limited here.

[0098] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for a power station AGC to pass through a vibration zone, characterized in that: include: When the power station meets the priority down-through input conditions, the priority down-through function is turned on, and according to the load curve, the strategy of not going through the vibration zone if possible is adopted, and when the power station meets the priority down-through exit conditions, the priority down-through function is turned off. The priority down-through input condition is that the whole plant AGC is in operation and the immediate down-through pressure plate is not in operation; the priority down-through exit condition is that when the immediate down-through pressure plate is not in operation, the whole plant AGC exits; According to the unit shutdown needs, when the power station meets the immediate down-through pressure plate input conditions, the immediate down-through pressure plate is put into operation, and according to the current load, the strategy of down-through the vibration zone is adopted if it can be down-through, and when the power station meets the immediate down-through exit conditions, the immediate down-through pressure plate is exited. The immediate down-through pressure plate input condition is that the whole plant AGC is put into operation; the immediate down-through pressure plate exit condition is that a certain unit completes down-through to base load and automatically exits or the whole plant AGC exits; When the power station meets the automatic crossing input conditions, the automatic crossing function is turned on, and according to the current load, the strategy of crossing the vibration zone if possible is adopted, and when the power station meets the automatic crossing exit conditions, the automatic crossing function is turned off; The priority down-passing function is enabled, and according to the load curve, a strategy of not passing through the vibration zone is adopted, and when the power station meets the priority down-passing exit condition, the priority down-passing function is disabled, including: Synchronously adjust the load of all units to the upper edge of the vibration zone through AGC; When the total unit has a reduction margin but the reduction margin cannot meet the load requirements or the total unit has no reduction margin, the unit with the highest priority is selected to pass through the vibration zone to the base load; Automatically exit the single-machine AGC, and the AVC program will reduce the reactive power of the downstream unit to within the allowable shutdown range, and the reactive power of the remaining units will synchronously match the reactive power adjustment amount of the downstream unit. After the adjustment is completed, exit the single-machine AVC, and the priority downstream function of the unit with the highest priority will exit; When the priority down-passing function is executed, the following conditions must be met: Only when it is necessary to pass through the vibration zone, the units with higher priority will have priority to pass through, and in other periods, they will participate in the AGC regulation of the whole plant normally; When a unit passes through the vibration zone first, it is not allowed to cause other units to pass through the vibration zone for matching; The priority down-crossing function is put into operation. After the unit with the highest priority down-crosses to base load and exits the single-unit AGC, if the single-unit AGC of the unit is put into operation again, the up-crossing vibration zone adjustment will be performed according to the up-crossing vibration zone strategy; The method further comprises: When the total unit has a reduction margin and the reduction margin can meet the load requirements, under the premise that no unit passes through the vibration zone, the load of each unit is adjusted according to the priority, and the AVC program completes the reduction of the reactive power of the unit to within the allowable shutdown range, and the reactive power of other units is synchronously matched with the reactive power adjustment amount of the unit. In principle, the matching process adopts one-to-one adjustment; The immediate penetration pressure plate is put into use, and according to the current load, a strategy of passing through the vibration zone if possible is adopted, and when the power station meets the immediate penetration exit condition, the immediate penetration pressure plate is exited, including: Set the priority of the shutdown unit to the highest and put the immediate down-load pressure plate into operation, and use AGC to detect whether the adjustment capacity of other units meets the down-load capacity of the shutdown unit; If the regulating capacity of other units meets the requirement of the shutdown unit to pass through the base load, the shutdown unit will be immediately reduced to pass through the vibration zone to the base load, and other units will be adjusted up in turn, among which the unit with the lowest load will be given priority to match and increase; When the shutdown unit passes through the base load, the single-unit AGC and the immediate pressure plate are automatically exited, and the AVC program completes the reduction of the shutdown unit's reactive power to within the allowable shutdown range, and the reactive power of the remaining units synchronously matches the reactive power adjustment amount of the unit, and the single-unit AVC is exited after the adjustment is completed; When the immediate down-through function is executed, the following conditions must be met: When other units are matched and adjusted during the immediate down-through process, the units with base load should be selected for matching and adjustment. During the load stable period, this process can complete the load replacement of the rotation units; Only when the immediate lower pressure plate is put into operation, are the two units allowed to simultaneously cross the vibration zone for matching adjustment, one up and one down; When the whole plant AGC mode is put into operation and is in open-loop mode, it is allowed to put into operation and immediately penetrate the pressure plate. At this time, the load is only distributed but not executed; The method further comprises: If the regulating capacity of other units does not meet the requirement for the shutdown unit to pass down to base load, all units will normally execute the plant-wide AGC allocation strategy, and the plant load will be reduced until the regulating capacity of other units meets the requirement for the shutdown unit to pass down to base load; When the regulation capacity of other units meets the requirement that the shut-down unit can be reduced to base load, a margin threshold is set.

2. The method according to claim 1, characterized in that The automatic upper penetration input condition is that the whole plant AGC is put into operation and a single unit AGC of a base load operation unit is put into operation; The automatic crossing exit condition is that the whole plant AGC exits or a unit automatically adjusts to be consistent with the load of other AGC units after crossing the vibration zone, or a single unit AGC of a unit operating with base load exits.

3. The method according to claim 1, characterized in that The automatic crossing function is enabled, and according to the current load, a strategy of crossing the vibration zone if possible is adopted, and when the power station meets the automatic crossing exit condition, the automatic crossing function is disabled, including: For grid-connected units with base load, the automatic up-through function takes effect automatically after AGC is put into operation; The current load is calculated by AGC, and it is determined whether the current load satisfies the grid-connected unit with base load to pass through the stable operation zone and does not cause other units to pass through the vibration zone; If the current load satisfies the grid-connected base-load unit to cross over to the stable operation zone, the AGC automatically adjusts the active power of the grid-connected base-load unit to be consistent with other units. After the adjustment is completed, the automatic crossing function of the grid-connected base-load unit ends.

4. The method according to claim 3, characterized in that The method further comprises: If the current load does not satisfy the grid-connected base-load unit to cross over to the stable operation zone, the grid-connected base-load unit will keep the AGC in operation and wait until the current load at a certain moment satisfies the grid-connected base-load unit to cross over to the stable operation zone.

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