Power generation dispatching control method for power system unit

Abstract

The invention relates to a power generation dispatching control method for a power system unit. The invention aims to solve the problems that the adjustment difficulty of a thermal power generating unit of an electric power system is increased and the utilization efficiency of electric energy is low due to unstable new energy power generation in a novel electric power system. The method comprises the following steps: 1, acquiring an intraday power generation plan; 2, stipulating a demand level, and determining a priority when a plurality of demands occur at the same time; 3, generating a demand form, wherein the demand form comprises a section out-of-limit demand form, a frequency out-of-limit demand form, a tie line comprehensive control demand form and a service adjustment demand form; 4, setting a unit adjustment rule in the form; and 5, arranging the units to generate power according to the intra-day power generation plan, and when the frequency out-of-limit demand, the section out-of-limit demand, the tie line comprehensive control demand and the service adjustment demand occur, performing distribution according to the four-unit adjustment rule according to the demand. The method is applied to the field of automatic power generation control of power systems.

Description

Technical Field

[0001] The invention relates to a power system unit generation dispatching control method. Background Art

[0002] The automatic generation control system (AGC) of the power system is a system that adjusts the active output of multiple generators in different power plants in response to changes in load. It controls the output of frequency-modulated units to meet the ever-changing power needs of users. At present, the dispatching work is based on the daily power generation plan issued, and the online safety analysis system is used to verify the safe operation. Then, combined with the actual load conditions and power operation conditions of the day, the dispatching personnel make adjustments based on the daily power generation plan, and send instructions to the corresponding units of the power plant through the AGC system to achieve economic matching of power generation and load, and more importantly, to ensure the safe and stable operation of the power grid.

[0003] At present, the daily power generation plan adjustment work is mostly allocated according to the dispatcher's experience. This dispatching method has faced great challenges in recent years. First, the installed capacity of new energy is increasing year by year, and the instability and intermittent characteristics of new energy have brought challenges to the dispatching and balancing of the power system. Since the supply of renewable energy is affected by factors such as weather and seasons, the power generated by it fluctuates greatly, requiring flexible dispatching and balancing measures. Secondly, the dispatching of the power system must not only ensure the safe and stable operation of the power grid, but also ensure the completion of the dispatching assessment indicators, the completion of the planned power, and the advancement of the power market. This dispatching plan that needs to take into account multiple objectives is also urgently needed. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of increased difficulty in regulating thermal power units in power systems and low energy utilization efficiency caused by unstable new energy power generation in new power systems, and to propose a power system unit generation dispatching control method.

[0005] The specific process of the power system unit generation dispatching control method is as follows:

[0006] Step 1: Obtain a daily power generation plan, which includes the power generation of the planned units;

[0007] Step 2: Define the demand level, classify the frequency over-limit demand, section over-limit demand, interconnection line integrated control demand, and service adjustment demand, and determine the priority when multiple demands occur at the same time;

[0008] Step 3: Generate demand forms, including cross-section over-limit demand form, frequency over-limit demand form, interconnection line comprehensive control demand form and service adjustment demand form;

[0009] Step 4: Set the unit adjustment rules in the section over-limit demand form, frequency over-limit demand form, interconnection line comprehensive control demand form and service adjustment demand form;

[0010] Step 5: Arrange the unit power generation according to the daily power generation plan. When frequency over-limit demand, section over-limit demand, interconnection line comprehensive control demand, and service adjustment demand occur, allocate according to the demand and the unit adjustment rules in step 4.

[0011] The beneficial effects of the present invention are:

[0012] Due to the above difficulties in dispatching work, it is necessary to propose an automatic power generation control strategy, which is applied to the automatic power generation control system (AGC) of the power system. On the basis of the final published daily power generation plan of the thermal power units, according to the actual performance of each thermal power unit during the day, combined with the actual operation of the power grid and various adjustment needs (including sections, frequencies, interconnection lines, unit characteristics, etc.), it can comprehensively consider the actual operation of the power grid safety (power equipment, etc.), the completion of the planned power, and the optimization of the interconnection line indicators, while optimizing the single-machine instructions reasonably and executing the instructions efficiently and accurately.

[0013] The invention is helpful to unify the dispatching work standards, eliminate human factors as much as possible, and better meet the dispatching "three publics (openness, fairness, and justice)" requirements; it can better take into account the safe operation of each section and equipment of the power system, and better ensure the completion of the planned power; by adding the concept of "reversal value", the dispatching instructions are optimized, and the problems of low work efficiency and increased control costs of power plants caused by repeated adjustments of units are reduced; the grid operation adjustment requirements are divided into five levels according to their importance, and the AGC system realizes the overall adjustment of "grasping the main contradictions and taking into account the secondary contradictions". It further standardizes the dispatching management of the power grid, improves the efficiency of electric energy utilization, realizes the optimization and improvement of dispatching work under the background of the new power system, promotes energy reform, and generates huge economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0015] Specific implementation method 1: The specific process of the power system unit power generation dispatching control method in this implementation method is as follows:

[0016] Step 1: Obtain a daily power generation plan, which includes the power generation of the planned units;

[0017] Step 2: Define the demand levels (ABCDE), classify the frequency over-limit demand, section over-limit demand, interconnection line integrated control demand, and service adjustment demand, and determine the priority when multiple demands occur simultaneously;

[0018] Step 3: Generate demand forms, including cross-section over-limit demand form, frequency over-limit demand form, interconnection line comprehensive control demand form and service adjustment demand form;

[0019] Step 4: Set the unit adjustment rules in the section over-limit demand form, frequency over-limit demand form, interconnection line comprehensive control demand form and service adjustment demand form;

[0020] Step 5: Arrange the unit power generation according to the daily power generation plan. When there is a frequency over-limit demand, section over-limit demand, interconnection line comprehensive control demand, service adjustment demand, etc., allocate according to the demand according to the unit adjustment rules in step 4.

[0021] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that the demand level (ABCDE) is specified in step 2, and the frequency over-limit demand, section over-limit demand, tie line comprehensive control demand, and service adjustment demand are graded to determine the priority when multiple demands occur simultaneously; the specific process is:

[0022] Step 21. Sort the "demand" levels from high to low as: A-level demand, B-level demand, C-level demand, D-level demand, E-level demand;

[0023] The Class A requirement is: the power grid has been substantially damaged and must be adjusted immediately; for example, equipment is overloaded;

[0024] The Class B requirement is: the power grid faces a substantial threat, and failure to make timely adjustments will result in the dispatching agency being held responsible; for example, a section exceeds the limit;

[0025] The Class C requirement is: the power grid should not operate in this state for a long time and needs to be adjusted as soon as possible; for example, the section exceeds the setting limit;

[0026] Among them, setting limit: the section has not exceeded the limit but has reached the operating value that is about to exceed the limit, indicating that there is a risk of exceeding the limit, which will have a potential impact on the operation;

[0027] The D-level demand is: this type of demand always exists on a daily basis, and the dispatching agency should meet it, but failure to meet it usually does not cause consequences for safe operation; for example, there is a deviation between the actual power generation and the planned power generation;

[0028] The E-level demand is: the demand for the dispatching agency to actively serve the power plant when there is spare capacity;

[0029] Step 22: Classify the cross-section over-limit demand, frequency over-limit demand, interconnection line comprehensive control demand, and service adjustment demand. The classification standards are as follows:

[0030] The cross-section over-limit requirement is: a power adjustment requirement to relieve equipment overload and cross-section over-limit;

[0031] The frequency over-limit requirement is: a power supply adjustment requirement to control or alleviate the frequency over-limit;

[0032] The comprehensive control demand of the tie line is: due to the power generation plan and deviation power, to prevent the units from frequently increasing or decreasing output, and to fairly exert the regulation capacity of each unit;

[0033] The service adjustment demand is: to meet the demand generated by the power plant's self-adjustment of unit load distribution;

[0034] The cross section is: the sum of the power of one or more electric devices connected between one area and another area;

[0035] In the operation of the power system, important sections have specified limits, and when a section exceeds the specified limit, it is called a section over-limit;

[0036] The frequency is: system operating frequency;

[0037] The frequency over-limit refers to: the system operating frequency exceeds the prescribed limit and lasts for a certain period of time;

[0038] (1) The cross-section demand is divided into Class A demand, Class B demand, and Class C demand:

[0039] Class A requirement: Power equipment power overload (exceeding the allowable operating range) for 1 minute; power equipment includes generators, transformers, overhead lines, circuit breakers, switches, etc.

[0040] Class B demand: The section exceeds the stability limit, where the stability limit refers to the stable operation limit value of certain important sections, interconnection lines, transformers, etc. formulated by the power company to ensure the safe and stable operation of the power system, which lasts for 1 minute;

[0041] C-level demand: The section exceeds the setting limit, where the setting limit refers to the setting limit value where the power equipment does not exceed its own allowable operating range, but still has its own operating risk or may cause operating risks of other equipment, and lasts for 1 minute;

[0042] Power equipment is a physical structure, and the power system refers to the entire physical structure and its operating status;

[0043] (2) Frequency over-limit demands are divided into Class A demands, Class B demands, and Class C demands:

[0044] Class A requirement: power system operating frequency f≥50.2Hz, f≤49.8Hz, for 1min; f is the power system operating frequency;

[0045] Class B requirement: power system operating frequency 50.1≤f<50.2Hz, 49.8<f≤49.9Hz, for 1min;

[0046] Class C requirement: power system operating frequency 50.08≤f<50.1Hz, 49.9<f≤49.92Hz, for 1min;

[0047] (3) The comprehensive control requirement of the tie line is Class D;

[0048] Level D demand: long-term demand, the level remains unchanged; for example, there is a deviation between the actual power generation and the planned power generation;

[0049] (4) The service adjustment requirement is E-level requirement;

[0050] E-level demand: long-term demand, unchanged level; the dispatching agency actively provides services to the power plant when it has spare capacity;

[0051] Step 23: Determine the priority when multiple requirements occur simultaneously; the specific process is:

[0052] Based on the priority of the demands, the units are assigned to respond to the higher-level demands first, and then to the lower-level demands in turn.

[0053] The other steps and parameters are the same as those in the first embodiment.

[0054] Specific implementation method three: This implementation method is different from specific implementation methods one or two in that a demand form is generated in step three, and the demand form includes a cross-section over-limit demand form, a frequency over-limit demand form, a tie line comprehensive control demand form, and a service adjustment demand form; the specific process is:

[0055] There may be multiple "demands" of the same level in the system at the same time. Each demand has a corresponding lock, and these locked units are aggregated together to form part of the demand form.

[0056] Each demand has a corresponding unit involved in the adjustment, and these units involved in the adjustment are aggregated to form another part of the demand form.

[0057] Lockout: The output of some units is limited under certain "demands" or operating modes, and cannot be adjusted or can only be adjusted in one direction. These units with adjustment restrictions will not be included in the four tables to allocate the adjustment amount;

[0058] There are three forms of blocking: the unit output cannot be adjusted at all, the unit output cannot be less than a certain threshold (i.e. the output reduction direction is blocked), and the unit output cannot be greater than a certain threshold (the output increase direction is blocked). Blocking direction: The blocked unit stipulates that it can only increase or decrease or cannot be adjusted at all;

[0059] It should be noted that when some units in the low-level demand need to be locked, and the high-level demand generated at the same time requires adjustment of the unit, the unit can be adjusted, that is, the high-level demand is given priority.

[0060] There are some units that need to be locked in Class A demand. They do not participate in the unit output adjustment and are not included in the unit adjustment list. These units that do not participate in the adjustment are collectively referred to as units that need to be locked in Class A demand, that is, Class A locking.

[0061] If a Class A demand requires a unit to be adjusted, and a Class B demand that occurs at the same time does not require this unit to be adjusted, then this unit needs to be adjusted; if a Class A demand requires a unit to be locked, that is, it cannot be adjusted, and a Class B demand requires another unit to be locked, then both units need to be locked; or if the Class A demand does not require a unit to be locked, but the Class B demand requires this unit to be locked, then this unit needs to be locked.

[0062] The demand form contains the current demand level, a list of all units associated with the demand, their sequence, and the blocking direction of the units to meet the demand;

[0063] All units associated with demand are: units that can affect demand by adjusting unit output or blocking unit output;

[0064] (1) The demand form includes four forms: "To be added", "Added", "To be removed", and "Removed";

[0065] Initialize the units and the order of units in the "To be added table", "Added table", "To be reduced table" and "Reduced table"; specifically:

[0066] The units whose actual output is greater than the output in the daily plan are placed in the waiting-to-be-reduced table, and the rest are placed in the waiting-to-be-added table. The added table or reduced table is an empty table.

[0067] The order of units in the waiting list is arranged from high to low according to the under-generated power of the under-generated units (the units with priority to increase power) in the OMS system.

[0068] The order of units in the table to be reduced: Arrange from high to low according to the excess power generation of the excess generating units (units with priority to reduce output) in the OMS system;

[0069] The initial order of the units in the waiting-to-add table and the waiting-to-remove table is the order of priority to catch up with the power deviation given by the OMS system;

[0070] The under-generated units are the units whose actual power generation is less than the planned power generation, and the under-generated power is the under-generated power;

[0071] Similarly, an over-generating unit is a unit that actually generates more electricity than planned, and the excess electricity is the over-generated electricity.

[0072] Each unit or newly started unit is assigned a reversal value with an initial value of zero. Whenever the unit moves from the addition table (to be added table and the added table) to the reduction table (to be reduced table and the reduced table), or from the reduction table to the addition table, the reversal value is +0.5;

[0073] (2) Read all units with non-zero section correlation coefficients from the four tables "To be added", "Added", "To be reduced" and "Reduced" as the section over-limit demand table;

[0074] (3) Read all units from the four tables of "to be added", "added", "to be reduced" and "reduced" as the frequency over-limit demand table;

[0075] (4) When the demand adjustment amount is to increase the output, the "to be added table" is used as the comprehensive control demand table of the contact line;

[0076] When the demand adjustment amount is to reduce output, the "to be reduced table" is used as the comprehensive control demand form of the contact line;

[0077] (5) Read all units from the four tables "To be added", "Added", "To be reduced" and "Reduced" as service adjustment demand tables.

[0078] The other steps and parameters are the same as those in the first or second embodiment.

[0079] Specific implementation method 4: This implementation method is different from any one of specific implementation methods 1 to 3 in that in step 4, the unit adjustment rules in the section over-limit demand form, the frequency over-limit demand form, the tie line comprehensive control demand form and the service adjustment demand form are set; the specific process is:

[0080] Step 41. Adjustment of the unit in the cross-section limit demand form:

[0081] Sorting adjustment:

[0082] When the demand is level A, the units are sorted from high to low according to the absolute value of the correlation coefficient between the unit and the section (a number indicating the degree of association between the unit and a section);

[0083] The correlation coefficient between the unit and the section includes the correlation coefficient between each unit and each section, and the correlation coefficient between each unit and each section is taken from the line safety analysis system;

[0084] When the demand is Class B or C, the units are ranked as Class I, Class II, Class III, and Class IV;

[0085] Category 1: The unit should reduce output and is in the waiting reduction table, or the unit should increase output and is in the waiting increase table;

[0086] Category II: The unit should reduce output and is within the reduced table, or the unit should increase output and is within the increased table;

[0087] Category III: The unit should reduce output and is within the added table, or the unit should increase output and is within the reduced table;

[0088] Category 4: The unit should reduce output and is in the waiting-to-increase table, or the unit should increase output and is in the waiting-to-decrease table;

[0089] Step 42: Adjustment of units in the frequency over-limit demand form:

[0090] When the operating frequency of the power system is greater than or equal to 50Hz, the order is: all units in the table to be reduced and keep the order, all units in the table to be reduced and keep the order, all units in the table to be added are sorted in reverse order, and all units in the table to be added are sorted in reverse order;

[0091] When the operating frequency of the power system is less than 50Hz, the order is: all units in the waiting list are kept in order, all units in the added list are kept in order, all units in the reduced list are sorted in reverse order, and all units in the waiting list are sorted in reverse order;

[0092] Step 43: Adjustment of contact line comprehensive control form:

[0093] The adjustment rules of the contact line comprehensive control form, that is, the adjustment rules of the four tables "to be added / reduced" and "added / reduced"; the principles are as follows:

[0094] Basic rules for sorting the four tables: Sort by the integer part of the reversal value from small to large, and sort by OMS order if the integer part of the reversal value is the same; when there is no unit with a reversal value of 0, the reversal value of all units will be immediately -0.5 to prevent the reversal value from accumulating too large;

[0095] (1) Rules for moving units into the added and subtracted tables:

[0096] When the unit in the waiting table receives the output increase command from the automatic generation control system AGC, the unit moves to the added table;

[0097] When the units in the waiting-to-be-reduced table receive the output reduction command from the automatic generation control system AGC, the units move to the reduced table;

[0098] (2) Rules for moving units into the waiting-to-add and waiting-to-remove tables:

[0099] First, define the response: In the added table or the reduced table, the absolute value of the unit output change greater than 1% is the response;

[0100] There are four rules for units in the added table to be moved to the waiting addition / reduction table: reaching the standard, pardon, punishment, and release, which correspond to the four situations that the normal response to the increase output command exceeds the allowable deviation range of the intraday plan value, does not respond to the increase output command but the output reaches the reporting capacity, does not respond to the increase output command but outputs and does not reach the reporting capacity, does not respond to the increase output command and does not reach the reporting capacity and has been fully assessed. The specific rules are as follows:

[0101] a) Achievement rules: If a unit in the added table responds to the output increase command at any time, and the current output of the unit after responding to the output increase command has reached or exceeded the allowable deviation range of the daily plan (temporarily set at 5%), the unit will be moved to the waiting table; if the current output of the unit after responding to the output increase command does not reach the allowable deviation range of the daily plan, the unit will be moved to the waiting table;

[0102] b) Amnesty Rules:

[0103] The timer starts counting when the automatic generation control system AGC issues an output increase command to the unit, and stops counting when the unit's power generation reaches the required level.

[0104] When the timer reaches 15 minutes, the unit's power generation still does not meet the requirements, and the unit's output has reached the upper limit of the reporting capacity, the handling method is to move the unit into the waiting reduction table;

[0105] Reported capacity: the upper limit of the actual power generation capacity reported by the power plant to the dispatching agency (the actual power generation capacity of some units is inconsistent with the rated value due to aging and other reasons);

[0106] c) Penalty rules:

[0107] The timer starts counting when the automatic generation control system AGC issues an output increase command to the unit, and stops counting when the unit's power generation reaches the required level.

[0108] When the timing reaches 15 minutes, the unit's power generation still does not meet the requirements, and the unit output does not reach the upper limit of the reporting capacity, and the command value (how much each unit is allocated) does not reach 5% of the demand. The solution is to move the unit to the waiting table;

[0109] d) Release rules:

[0110] The timer starts counting when the automatic generation control system AGC issues an output increase command to the unit, and stops counting when the unit's power generation reaches the required level.

[0111] When the timing reaches 1 hour, the unit's power generation still does not meet the requirements;

[0112] The solution is to move the unit into the waiting reduction table;

[0113] (3) Rules for adequacy of form units (supplementary rules):

[0114] If the units in the to-be-added table / to-be-reduced table are not sufficient to meet the AGC's needs for increasing or decreasing output (a response command overflow alarm occurred in the previous round, that is, the system operation requires the units to increase their output, but all units have reached the maximum allowable output and cannot increase their output any further, so there are no units in the to-be-added table; or vice versa), the interconnection line comprehensive control form will no longer default to the to-be-added table.

[0115] If the units in the table to be added are not enough to meet the output increase demand of the automatic generation control AGC command, the command overflow alarm will be given once, and the output of the units in the table that have been added will be adjusted;

[0116] If the units in the table to be added and the table already added are not enough to meet the needs of the automatic generation control AGC command to increase the output, the command overflow alarm is given twice, and the units in the table already reduced are sorted in reverse order for output adjustment;

[0117] If the units in the table to be added, the table to be added, and the table to be reduced are not enough to meet the needs of the automatic generation control AGC command to increase the output, the command overflow alarm will be issued 3 times, and the units in the table to be reduced will be sorted in reverse order for output adjustment;

[0118] If the units in the to-be-added table, added table, reduced table, and to-be-reduced table are still insufficient to meet the needs of the automatic generation control AGC command to increase output, the command overflow alarm is triggered 4 times, and the current output of the units remains unchanged (the situation when the command overflow alarm is triggered 4 times);

[0119] If there is no alarm for five minutes, the contact line integrated control form will be returned one level upward (4 times of command overflow alarm will be returned to 3 times, 3 times will be returned to 2 times);

[0120] If the units in the table to be reduced are not enough to meet the needs of reducing the output of the automatic generation control AGC command, the command overflow alarm will be issued once, and the units in the table that have been reduced will adjust their output;

[0121] If the units in the table to be reduced and the table that have been reduced are still insufficient to meet the needs of reducing the output of the automatic generation control AGC command, the command overflow alarm will be issued twice, and the units in the table that have been added will be sorted in reverse order for output adjustment;

[0122] If the units in the table to be reduced, the table to be reduced, and the table to be added are not enough to meet the needs of the automatic generation control AGC command to reduce output, the command overflow alarm will be issued 3 times, and the units in the table to be added will be sorted in reverse order for output adjustment;

[0123] If the units in the to-be-reduced, reduced, added, and to-be-added meters are still insufficient to meet the needs of reducing output commanded by the automatic generation control AGC, the command overflow alarm will be given 4 times, and the current output of the units will remain unchanged (the situation when the command overflow alarm is given 4 times);

[0124] If there is no alarm for five minutes, the contact line integrated control form will be returned one level upward (4 times of command overflow alarm will be returned to 3 times, 3 times will be returned to 2 times);

[0125] Step 44: No adjustment is required for the service adjustment request form;

[0126] The other steps and parameters are the same as those in Specific Embodiments 1 to 3.

[0127] Specific implementation method five: This implementation method is different from any one of specific implementation methods one to four in that in step five, the unit power generation is arranged according to the daily power generation plan. When frequency over-limit demand, section over-limit demand, interconnection line comprehensive control demand, service adjustment demand and other conditions occur, the unit adjustment rules in step four are used for allocation according to the demand; the specific process is as follows:

[0128] Step 51: Determine the unit allocation for a single demand:

[0129] For a single demand (such as a section demand), the sum of the outputs to be adjusted of all units in the current demand form (initial or transformed), i.e. the demand, is allocated to each single unit according to the trapezoidal method. The allocation of a single unit shall not be less than 2% of the demand and not more than 5% of the demand, until the sum of the adjustment amount allocated to each single unit is equal to the demand in the demand form, otherwise it will continue to be allocated to each single unit until all units in the demand form are used up and the allocation amount of all units in the form reaches the maximum;

[0130] AGC issues a command to the unit at fixed time intervals. The unit follows the command of AGC, and after several command cycles, it reaches the maximum change allowed for allocation, or does not reach the maximum change allowed for allocation of a single unit, but the system as a whole reaches the required adjustment amount. Between adjacent commands of the same unit, the output only increases or decreases by 1%. In order to ensure that the under-generating unit at the front end of the table to be added can give priority and increase the output as much as possible, the over-generating unit at the front end of the table to be reduced can reduce the output as much as possible. When the increase in output is not higher than 5% of the demand, the first of the two adjacent units in the table generates 1% more than the second. When the output change of the unit reaches the maximum value, the current output value of the unit is maintained, and the output of the adjacent unit behind is continued to be increased, and so on. Finally, a trapezoidal structure is formed in which the output increase of the unit at the front end of the table is the maximum change allowed for allocation of a single unit, and the change of the subsequent units decreases by 1% in sequence.

[0131] Assume that there are n generators involved in the regulation in the table. Before the command is given, the output of each generator is AGC issues new output adjustment commands to the unit at fixed time intervals. The commands are sorted over time. The time when the command is issued is set to t, t = 1, 2, 3, ..., and the additional output at each time compared to the initial time (the time when the demand occurs) is The output of the nth unit at time t for:

[0132]

[0133] The demand adjustment amount is P, and the adjacent moments are adjusted in units of 1% of the demand adjustment amount. When a new unit participates in the adjustment, the minimum initial adjustment amount is not less than m min %P, and the adjustment amount of each unit is not greater than m max %P, that is m t =m min ,m min +1,…,m max

[0134] m min The value is 2, m max The value is 5; m t The values ​​are 2, 3, 4, and 5;

[0135] Among them, m t The relationship with t is:

[0136] for Right now

[0137] for Right now

[0138] for

[0139] For example, there are four units in the table, and the order of the units is a, b, c, d

[0140] The unit output is distributed according to the steps in the following table, where each unit increases its initial output by m. t As shown in the table.

[0141] t a b c d 1 2 0 0 0 2 3 0 0 0 3 3 2 0 0 4 4 2 0 0 5 4 3 0 0 6 4 3 2 0 7 5 3 2 0 8 5 4 2 0 9 5 4 3 0 10 5 4 3 2 11 5 5 3 2 12 5 5 4 2 13 5 5 4 3 14 5 5 5 3 15 5 5 5 4 16 5 5 5 5

[0142] The allocation principle is to allow as many units in the table as possible to participate in the regulation, while ensuring that the regulation amount is in descending order according to the table order;

[0143] The above calculation example temporarily sets the minimum adjustment accuracy of the AGC command to 1%. It should be noted that for the units that have been assigned the reverse adjustment command in the previous round, the allocation in this round should be based on the current output; for the units that have been assigned the forward adjustment command, the allocation should be based on the current command.

[0144] Step 52: Determine the unit allocation according to multi-level demand:

[0145] When facing multiple levels and multiple demands at the same time, the response to all demands shall be completed in the order of A-level blocking → A-level allocation → B-level blocking → B-level allocation → C-level blocking → C-level allocation → D-level blocking → D-level allocation → E-level blocking → E-level allocation; the details are as follows:

[0146] First, check all locked units in Class A requirements, and lock all locked units according to the locking direction;

[0147] Then, each Class A demand is allocated in turn according to the unit adjustment rules in step 4 (units whose allocation direction has been blocked shall not be allocated again); in the case where multiple demands of the same level allocate adjustment amounts to the same unit (the allocation direction must be the same at this time, because the reverse direction has been blocked), the largest adjustment amount among the demands of the same level is taken as the adjustment amount of the unit;

[0148] Then check all the units that are locked in the B-level requirements. The units continue to be locked on the basis of the A-level locking, that is, ensure that the locking conditions of the A-level locked units remain unchanged, and then add the units that need to be locked;

[0149] Then, each Class B demand is allocated in turn according to the unit adjustment rules in step 4 (the allocation direction that has been blocked cannot be allocated again); when multiple demands of the same level allocate adjustment amounts to the same unit (the allocation direction must be the same at this time, because the reverse direction has been blocked), the one with the largest adjustment amount among the demands of the same level is taken as the adjustment amount of the unit;

[0150] C, D, E level requirements and so on are handled in the same way to complete the response to all requirements.

[0151] The other steps and parameters are the same as those in Specific Embodiments 1 to 4.

[0152] The power generation order of each automatic generation control AGC unit is taken from the monthly power generation plan progress deviation compensation requirements in the OMS system.

[0153] Upper and lower limits of the unit: retrieve the upper and lower limit data of the daily power generation system, and provide correction feedback to the daily power generation plan according to the performance of the unit;

[0154] The actual operation status of the power grid: including the start and stop status of each unit, the actual output of each unit, the system frequency status, and the output of other energy sources. The start and stop status of each unit, the actual output of each unit, the system frequency status, and the output of other energy sources are read from the D5000 system.

[0155] When performing automatic power generation control, depending on the different conditions of the power grid, different situations may occur, such as daily adjustments, special situations (including adjustments in accordance with network adjustment instructions, adjustments in power grid emergencies, and other various load rate adjustment needs for some or all units), and system abnormalities at the master station end. At the same time, according to the goals to be achieved by the interconnection line adjustment under daily adjustments, there will be adjustment targets such as CPS optimization targets (reducing CPS penalties), ACE tracking targets (ACE zero adjustment), and thermal power deep adjustment targets (adjustments under thermal power deep adjustment mode).

[0156] According to the above different situations and goals, the corresponding demand adjustment amount is calculated to meet the adjustment needs in various situations. At the same time, as a demand-oriented system, the automatic power generation control system should adopt a unified demand-oriented logical framework to ensure the identity under different modes. In this design, the adjustment demand is connected with the thermal power unit by establishing a demand form, and different units are sorted, which establishes the foundation of the automatic power generation control system.

[0157] For algorithms that target deep adjustment, the dispatcher needs to operate the AGC master station and first agree to enter deep adjustment level 1 or level 2.

[0158] If the first gear is entered, the lower limit of the adjustable unit will be lowered to the higher of -5% and 40% of the planned value, and once the unit is lower than the deep adjustment threshold, the upper limit of the adjustable unit will be lowered to the lower of the deep adjustment threshold and +5% of the planned value.

[0159] If the second level of deep adjustment is entered, the lower limit of the adjustable unit will be lowered to the planned value -5%, and for the unit once it is lower than 40%, the upper limit of the adjustable unit will be lowered to the lower of 40% and the planned value +5%.

[0160] At the same time, since it has entered the deep adjustment stage, the adjustment target of the gateway contact line should not fluctuate too much. The target algorithm is planned to be changed to the ACE tracking algorithm, in which the starting value is set at 0 to -200,000 and the tracking value is set at -100,000; or it can still be adjusted according to the CPS standard, but the ΔM / Δ adjustment is appropriately enlarged so that the contact line tracking target does not change easily.

[0161] The present invention may also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for controlling power generation dispatching of power system units, characterized in that: The specific process of the method is: Step 1: Obtain a daily power generation plan, which includes the power generation of the planned units; Step 2: Define the demand level, classify the frequency over-limit demand, section over-limit demand, interconnection line integrated control demand, and service adjustment demand, and determine the priority when multiple demands occur at the same time; Step 3: Generate demand forms, including cross-section over-limit demand form, frequency over-limit demand form, interconnection line comprehensive control demand form and service adjustment demand form; Step 4: Set the unit adjustment rules in the section over-limit demand form, frequency over-limit demand form, interconnection line comprehensive control demand form and service adjustment demand form; Step 5: Arrange the unit power generation according to the daily power generation plan. When frequency over-limit demand, section over-limit demand, interconnection line comprehensive control demand, and service adjustment demand occur, allocate according to the demand and the unit adjustment rules in step 4.

2. The power system unit generation dispatching control method according to claim 1 is characterized in that: In the step 2, the demand level is specified, and the frequency over-limit demand, section over-limit demand, interconnection line comprehensive control demand, and service adjustment demand are graded to determine the priority when multiple demands occur at the same time; the specific process is: Step 21. Sort the "demand" levels from high to low as: A-level demand, B-level demand, C-level demand, D-level demand, E-level demand; Step 22: Classify the cross-section over-limit demand, frequency over-limit demand, interconnection line comprehensive control demand, and service adjustment demand. The classification standards are as follows: The cross-section over-limit requirement is: a power adjustment requirement to relieve equipment overload and cross-section over-limit; The frequency over-limit requirement is: a power supply adjustment requirement to control or alleviate the frequency over-limit; The said integrated control demand of the tie line is: the demand generated in order to give full play to the regulating capacity of each unit; The service adjustment demand is: to meet the demand generated by the power plant's self-adjustment of unit load distribution; (1) The cross-section demand is divided into Class A demand, Class B demand, and Class C demand: Class A requirement: Power equipment power overload lasts for 1 minute; power equipment includes generators, transformers, overhead lines, circuit breakers, and switches; Level B requirement: The section exceeds the stability limit for 1 minute; C-level demand: the section exceeds the setting limit for 1 minute; (2) Frequency over-limit demands are divided into Class A demands, Class B demands, and Class C demands: Class A requirements: power system operating frequency f ≥ 50.2 Hz, f ≤ 49.8 Hz, for 1 min; f is the operating frequency of the power system; Class B requirement: power system operating frequency 50.1≤f<50.2Hz, 49.8<f≤49.9Hz, for 1min; Class C requirement: power system operating frequency 50.08≤f<50.1Hz, 49.9<f≤49.92Hz, for 1min; (3) The comprehensive control requirement of the tie line is Class D; (4) The service adjustment requirement is E-level requirement; Step 23: Determine the priority when multiple requirements occur simultaneously; the specific process is: Based on the priority of the demands, the units are assigned to respond to the higher-level demands first, and then to the lower-level demands in turn.

3. The power system unit generation dispatching control method according to claim 2 is characterized in that: In the step 3, a demand form is generated, which includes a cross-section over-limit demand form, a frequency over-limit demand form, a tie line comprehensive control demand form, and a service adjustment demand form; the specific process is as follows: (1) The demand form includes four forms: "To be added", "Added", "To be removed", and "Removed"; Initialize the units and the order of units in the "to be added table", "added table", "to be reduced table" and "reduced table"; specifically: The units whose actual output is greater than the output in the daily plan are placed in the waiting-to-be-reduced table, and the rest are placed in the waiting-to-be-added table. The added table or reduced table is an empty table. The order of units in the waiting list is arranged from high to low according to the power shortage of the units in the OMS system. The order of units in the waiting-for-reduction table is arranged from high to low according to the excess power generation of the excess generating units in the OMS system; Each unit or newly started unit is assigned a reversal value with an initial value of zero. Whenever the unit moves from the plus table to the minus table, or from the minus table to the plus table, the reversal value is +0.5; (2) Read all units with non-zero section correlation coefficients from the four tables "to be added", "added", "to be reduced" and "reduced" as the section over-limit demand table; (3) Read all units from the four tables of "to be added", "added", "to be removed" and "removed" as the frequency over-limit demand table; (4) When the demand adjustment amount is to increase the output, the "to be added table" is used as the comprehensive control demand table of the contact line; When the demand adjustment amount is to reduce output, the "to be reduced table" serves as the comprehensive control demand form of the contact line; (5) Read all units from the four tables "To be added", "Added", "To be reduced" and "Reduced" as service adjustment demand forms.

4. The power system unit generation dispatching control method according to claim 3 is characterized in that: In the step 4, the unit adjustment rules in the section over-limit demand form, the frequency over-limit demand form, the tie line comprehensive control demand form and the service adjustment demand form are set; the specific process is: Step 41. Adjustment of the unit in the cross-section limit demand form: Sorting adjustment: When the demand is level A, the units are sorted from high to low according to the absolute value of the correlation coefficient between the unit and the section; When the demand is Class B or C, the units are ranked as Class I, Class II, Class III, and Class IV; Category 1: The unit should reduce output and is in the waiting reduction table, or the unit should increase output and is in the waiting increase table; Category II: The unit should reduce output and is within the reduced table, or the unit should increase output and is within the increased table; Category III: The unit should reduce output and is within the added table, or the unit should increase output and is within the reduced table; Category 4: The unit should reduce output and is in the waiting-to-increase table, or the unit should increase output and is in the waiting-to-decrease table; Step 42: Adjustment of units in the frequency over-limit demand form: When the operating frequency of the power system is greater than or equal to 50Hz, the order is: all units in the table to be reduced and keep the order, all units in the table to be reduced and keep the order, all units in the table to be added are sorted in reverse order, and all units in the table to be added are sorted in reverse order; When the operating frequency of the power system is less than 50Hz, the order is: all units in the waiting list are kept in order, all units in the added list are kept in order, all units in the reduced list are sorted in reverse order, and all units in the waiting list are sorted in reverse order; Step 43: Adjustment of contact line comprehensive control form: (1) Rules for moving units into the added and subtracted tables: When the unit in the waiting table receives the output increase command from the automatic generation control system AGC, the unit moves to the added table; When the units in the waiting-to-be-reduced table receive the output reduction command from the automatic generation control system AGC, the units move to the reduced table; (2) Rules for moving units into the waiting-to-add and waiting-to-remove tables: a) Achievement rule: If a unit in the added table responds to the output increase command at any time, and the current output of the unit after responding to the output increase command has reached or exceeded the allowable deviation range of the daily plan, the unit will be moved to the waiting reduction table; When the current output of the unit after responding to the output increase command does not reach the allowable deviation range of the daily plan, the unit will be moved to the waiting table; b) Amnesty Rules: The timer starts counting when the automatic generation control system AGC issues an output increase command to the unit, and stops counting when the unit's power generation reaches the required level. When the timer reaches 15 minutes, the unit's power generation still does not meet the requirements, and the unit's output has reached the upper limit of the reporting capacity, the handling method is to move the unit into the waiting reduction table; c) Penalty rules: The timer starts counting when the automatic generation control system AGC issues an output increase command to the unit, and stops counting when the unit's power generation reaches the required level. When the timing reaches 15 minutes, the unit's power generation still does not meet the requirements, and the unit output does not reach the upper limit of the reporting capacity, and the command value does not reach 5% of the demand, the processing method is to move the unit to the waiting table; d) Release rules: The timer starts counting when the automatic generation control system AGC issues an output increase command to the unit, and stops counting when the unit's power generation reaches the required level. When the timing reaches 1 hour, the unit's power generation still does not meet the requirements; The solution is to move the unit into the waiting reduction table; (3) Rules for the adequacy of the form unit: If the units in the table to be added are not enough to meet the output increase demand of the automatic generation control AGC command, the command overflow alarm will be given once, and the output of the units in the table that have been added will be adjusted; If the units in the table to be added and the table already added are not enough to meet the needs of the automatic generation control AGC command to increase the output, the command overflow alarm is given twice, and the units in the table already reduced are sorted in reverse order for output adjustment; If the units in the table to be added, the table to be added, and the table to be reduced are not enough to meet the needs of the automatic generation control AGC command to increase the output, the command overflow alarm will be given 3 times, and the units in the table to be reduced will be sorted in reverse order for output adjustment; If the units in the to-be-added table, added table, reduced table, and to-be-reduced table are still insufficient to meet the needs of the automatic generation control AGC command to increase output, the command overflow alarm will be given 4 times, and the current output of the units will remain unchanged; If there is no alarm for five minutes, the contact line comprehensive control form will be returned to the upper level; If the units in the table to be reduced are not enough to meet the needs of reducing the output of the automatic generation control AGC command, the command overflow alarm will be issued once, and the units in the table that have been reduced will adjust their output; If the units in the table to be reduced and the table that have been reduced are still insufficient to meet the needs of reducing the output of the automatic generation control AGC command, the command overflow alarm will be issued twice, and the units in the table that have been added will be sorted in reverse order for output adjustment; If the units in the table to be reduced, the table to be reduced, and the table to be added are not enough to meet the needs of the automatic generation control AGC command to reduce output, the command overflow alarm will be issued 3 times, and the units in the table to be added will be sorted in reverse order for output adjustment; If the units in the to-be-reduced, reduced, added, and to-be-added meters are still insufficient to meet the needs of reducing output commanded by the automatic generation control AGC, the command overflow alarm will be given 4 times, and the current output of the units will remain unchanged (the situation when the command overflow alarm is given 4 times); If there is no alarm for five minutes, the contact line comprehensive control form will be returned to the upper level.

5. The power system unit generation dispatching control method according to claim 4 is characterized in that: In step 5, the unit power generation is arranged according to the daily power generation plan. When the frequency over-limit demand, section over-limit demand, interconnection line comprehensive control demand, and service adjustment demand occur, the unit adjustment rules in step 4 are used for allocation according to the demand. The specific process is as follows: Step 51: Determine the unit allocation for a single demand: For a single demand, the sum of the outputs to be adjusted of all units in the demand form at the current moment, i.e. the demand, is allocated to each single unit according to the trapezoidal method. The allocation to a single unit shall not be less than 2% of the demand and not more than 5% of the demand, until the sum of the adjustment amount allocated to each single unit is equal to the demand in the demand form, otherwise it will continue to be allocated to each single unit until all units in the demand form are used up and the allocation amount of all units in the form reaches the maximum; Assume that there are n generators involved in the regulation in the table. Before the command is given, the output of each generator is AGC sends new output adjustment commands to the unit at fixed time intervals. The commands are sorted over time. The time when the command is issued is set to t, t = 1, 2, 3, ..., and the output added at each moment compared to the initial moment is The output of the nth unit at time t for: The demand adjustment amount is P, and the adjacent moments are adjusted in units of 1% of the demand adjustment amount. When a new unit participates in the adjustment, the minimum initial adjustment amount is not less than m min %P, and the adjustment amount of each unit is not greater than m max %P, that is m t =m min ,m min +1,…,m max m min The value is 2, m max The value is 5; m t The values ​​are 2, 3, 4, and 5; Among them, m t The relationship with t is: for Right now for Right now for Step 52: Determine the unit allocation according to multi-level demand: When facing multiple levels and multiple demands at the same time, the response to all demands shall be completed in the order of A-level blocking → A-level allocation → B-level blocking → B-level allocation → C-level blocking → C-level allocation → D-level blocking → D-level allocation → E-level blocking → E-level allocation; the details are as follows: First, check all locked units in Class A requirements, and lock all locked units according to the locking direction; Then, each Class A demand is allocated in turn according to the unit adjustment rule in step 4; when multiple demands of the same class are allocated adjustment amounts to the same unit, the largest adjustment amount among the demands of the same class is taken as the adjustment amount of the unit; Then check all the units that are locked in the B-level requirements. The units continue to be locked on the basis of the A-level locking, that is, ensure that the locking conditions of the A-level locked units remain unchanged, and then add the units that need to be locked; Then, each Class B demand is allocated in turn according to the unit adjustment rule in step 4; when multiple demands of the same class are allocated adjustment amounts to the same unit, the largest adjustment amount among the demands of the same class is taken as the adjustment amount of the unit; C, D, E level requirements and so on are handled in the same way to complete the response to all requirements.

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