Method and system for correcting primary frequency modulation deviation of hydroelectric generating set in opening degree adjusting mode

Abstract

The invention provides a hydroelectric generating set primary frequency modulation deviation correction method and system in an opening degree adjustment mode, and the method comprises the steps: obtaining a power grid frequency, a rated frequency, an actual output value of a hydroelectric generating set and a primary frequency modulation target adjustment proportion at a current moment, and determining a frequency deviation at the current moment; determining a primary frequency modulation target adjusting quantity, a primary frequency modulation reference quantity and an output target value at the current moment; when the hydroelectric generating set is in primary frequency modulation, the actual output value is not equal to the target output value and meets a first preset condition, determining a deviation correction pulse length and a pulse length gain coefficient at the current moment; according to the deviation correction pulse length and the pulse length gain coefficient, the actual deviation correction pulse length at the current moment is determined, the guide vane opening degree of the hydroelectric generating set is adjusted, and then correction of the primary frequency modulation deviation of the hydroelectric generating set is achieved. According to the technical scheme provided by the invention, the primary frequency modulation is rectified by opening the rectification pulse, the regulation performance of the primary frequency modulation is improved, and the frequency stability of a power grid is ensured.

Description

Technical Field

[0001] The present application relates to the field of power system automation control, and in particular to a method and system for correcting primary frequency regulation deviation of a hydropower unit in an opening regulation mode. Background Art

[0002] The output regulation mode of a hydropower station mainly includes a power regulation mode and an opening regulation mode. The difference between the two is that in the power regulation mode, the speed governor performs closed-loop feedback regulation on the actual output value of the unit according to the unit output target value; in the opening regulation mode, the monitoring system sends a regulation pulse to the speed governor according to the deviation between the unit output target value and the actual output value of the unit, and corrects the guide vane opening setting value of the speed governor, and the speed governor performs closed-loop feedback regulation on the guide vane opening according to the guide vane opening target value. The opening regulation mode in the prior art is to achieve compatible regulation of the primary frequency regulation by the secondary frequency regulation without changing the primary frequency regulation mechanism, by superimposing the primary frequency regulation target regulation amount to the unit output setting value, or by changing the primary frequency regulation mechanism from the speed governor to the monitoring system, and the speed governor is only responsible for closed-loop regulation of the guide vane opening under the control of the monitoring system, and there is a deviation in the regulation, and the regulation effect is poor. Therefore, it is urgent to propose a scheme for efficient, stable and correct primary frequency regulation regulation of hydropower units under the opening regulation mode. Summary of the invention

[0003] The present application provides a method and system for correcting the primary frequency regulation deviation of a hydropower unit in an opening regulation mode, so as to at least solve the technical problems of regulation deviation and poor regulation effect.

[0004] The first embodiment of the present application provides a method for correcting the primary frequency regulation deviation of a hydropower unit in an opening regulation mode, the method comprising:

[0005] Obtaining the grid frequency, rated frequency, actual output value of the hydropower unit and primary frequency regulation target adjustment ratio at the current moment, and determining the frequency deviation at the current moment based on the grid frequency and rated frequency at the current moment;

[0006] Determine the primary frequency regulation target adjustment amount at the current moment according to the frequency deviation at the current moment, and determine the primary frequency regulation reference amount, and then determine the output target value of the hydropower unit at the current moment according to the primary frequency regulation target adjustment amount and the primary frequency regulation reference amount;

[0007] When the hydropower unit at the current moment is in primary frequency regulation, the actual output value of the hydropower unit is not equal to the target output value of the hydropower unit and the first preset condition is met, the deviation correction pulse length and the pulse length gain coefficient at the current moment are determined according to the actual output value of the hydropower unit, the target adjustment amount of the primary frequency regulation, the primary frequency regulation reference amount, and the target adjustment ratio of the primary frequency regulation;

[0008] The actual deviation correction pulse length at the current moment is determined according to the deviation correction pulse length and the pulse length gain coefficient at the current moment, and the guide vane opening of the hydropower unit is adjusted based on the actual deviation correction pulse length, thereby correcting the primary frequency regulation deviation of the hydropower unit.

[0009] Preferably, determining the frequency deviation at the current moment based on the grid frequency at the current moment and the rated frequency includes:

[0010] When the grid frequency is greater than the rated frequency, Δf=min[0, f n -f+f d ], where Δf is the frequency deviation, f n is the rated frequency, f is the grid frequency, f d It is the threshold value of hydropower primary frequency regulation action;

[0011] When the grid frequency is less than the rated frequency, Δf=max[0,f n -f-f d ];

[0012] When the grid frequency is equal to the rated frequency, Δf=0.

[0013] Further, determining a target frequency modulation amount at the current moment according to the frequency deviation at the current moment includes:

[0014] Obtaining a primary frequency regulation ratio adjustment coefficient, and taking the product of the frequency deviation at the current moment, the rated capacity of the hydropower unit and the primary frequency regulation ratio adjustment coefficient as the primary frequency regulation target adjustment amount at the current moment;

[0015] The step of determining a primary frequency modulation reference value comprises:

[0016] If the hydropower unit is in the secondary frequency regulation process, the output setting value of the hydropower unit corresponding to the current secondary frequency regulation instruction is used as the primary frequency regulation reference value;

[0017] If the hydropower unit is not in the process of secondary frequency regulation, the actual output value of the hydropower unit at the start time of the primary frequency regulation action is used as the primary frequency regulation reference value;

[0018] If the hydropower unit receives a secondary frequency regulation instruction during the primary frequency regulation action, the output setting value of the hydropower unit corresponding to the secondary frequency regulation instruction is used as the primary frequency regulation reference value.

[0019] Furthermore, the first preset condition includes:

[0020] The deviation between the actual output value of the hydropower unit and the target output value of the hydropower unit is less than the regulation dead zone;

[0021] The guide vane opening of the hydroelectric unit is not in the adjustment process, and the duration is greater than the preset first duration. Further, the deviation correction pulse length and pulse length gain coefficient at the current moment are determined according to the actual output value of the hydroelectric unit, the primary frequency regulation target adjustment amount, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment ratio, including:

[0022] Determine the deviation between the primary frequency regulation target adjustment amount and the primary frequency regulation actual adjustment amount at the current moment according to the primary frequency regulation target adjustment amount, the actual output value of the hydropower unit and the primary frequency regulation reference amount;

[0023] Determine the deviation between the actual primary frequency regulation adjustment ratio and the primary frequency regulation target adjustment ratio at the current moment according to the primary frequency regulation target adjustment ratio, the actual output value of the hydropower unit, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment amount;

[0024] Determining the deviation correction pulse length at the current moment according to the deviation between the primary frequency modulation target adjustment amount at the current moment and the primary frequency modulation actual adjustment amount;

[0025] The pulse length gain coefficient at the current moment is determined according to the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation.

[0026] Furthermore, the step of determining the deviation between the primary frequency regulation target adjustment amount and the primary frequency regulation actual adjustment amount at the current moment according to the primary frequency regulation target adjustment amount, the actual output value of the hydropower unit and the primary frequency regulation reference amount includes:

[0027] Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation value;

[0028] Determine the difference between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation, and use the difference as the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation;

[0029] The method of determining the deviation between the primary frequency regulation target adjustment ratio and the primary frequency regulation actual adjustment ratio at the current moment according to the primary frequency regulation target adjustment ratio, the actual output value of the hydropower unit, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment amount includes:

[0030] Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation value;

[0031] The ratio of the actual adjustment amount of the primary frequency regulation to the target adjustment amount of the primary frequency regulation is used as the actual adjustment ratio of the primary frequency regulation;

[0032] The difference between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation is determined, and the difference is used as the deviation between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation.

[0033] Furthermore, the calculation formula of the deviation correction pulse length is as follows:

[0034] v t =Δp t ×u

[0035] In the formula, v t is the deviation correction pulse length at the current time t, Δp t is the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation, and u is the preset basic pulse length.

[0036] Further, the pulse length gain coefficient at the current moment is determined according to the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation, including:

[0037] Obtaining a preset gain coefficient group and a proportional threshold corresponding to the gain coefficient group, wherein the number of gain coefficients in the preset gain coefficient group is N, the number of proportional thresholds is N-1, and the proportional thresholds are arranged from small to large;

[0038] If the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation at the current moment is less than or equal to the first ratio threshold, the first gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment;

[0039] If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the last ratio threshold, the last gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment;

[0040] If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the m-1th ratio threshold and less than or equal to the mth ratio threshold, the mth gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment.

[0041] Furthermore, the actual deviation correction pulse length at the current moment is determined according to the deviation correction pulse length at the current moment and the pulse length gain coefficient, and the guide vane opening of the hydropower unit is adjusted based on the actual deviation correction pulse length, thereby correcting the primary frequency modulation deviation of the hydropower unit, including:

[0042] When the pulse length gain coefficient is equal to zero, the actual correction pulse length at the current moment is equal to zero;

[0043] When the pulse length gain coefficient is not equal to zero:

[0044] If the current deviation correction pulse length is greater than zero, then use the formula Δv t =v t ×θ t ×β+σ, determine the actual deviation correction pulse length at the current moment, and increase the guide vane opening to correct the deviation based on the actual deviation correction pulse length;

[0045] If the current deviation correction pulse length is less than zero, then use the formula Δv t =v t ×θ t ×β-σ, determine the actual deviation correction pulse length at the current moment, and reduce the guide vane opening to perform deviation correction based on the actual deviation correction pulse length;

[0046] Where Δv t is the actual correction pulse length at the current time t, v t is the deviation correction pulse length at the current time t, θ t is the pulse length gain coefficient at the current time t, β is the associated parameter, and σ is the preset first parameter.

[0047] The second embodiment of the present application proposes a primary frequency regulation deviation correction system for a hydropower unit in an opening adjustment mode, comprising:

[0048] An acquisition module, used for acquiring the grid frequency, rated frequency, actual output value of the hydropower unit and target adjustment ratio of the primary frequency regulation at the current moment when the hydropower unit is in primary frequency regulation at the current moment and meets the first preset condition, and determining the frequency deviation at the current moment based on the grid frequency and rated frequency at the current moment;

[0049] A first determination module is used to determine the primary frequency regulation target adjustment amount at the current moment according to the frequency deviation at the current moment, and determine the primary frequency regulation reference amount, and then determine the output target value of the hydropower unit at the current moment according to the primary frequency regulation target adjustment amount and the primary frequency regulation reference amount;

[0050] The second determination module is used to determine the deviation correction pulse length and pulse length gain coefficient at the current moment according to the actual output value of the hydropower unit, the primary frequency regulation target adjustment amount, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment ratio when the hydropower unit is in primary frequency regulation at the current moment, the actual output value of the hydropower unit is not equal to the output target value of the hydropower unit and the first preset condition is met;

[0051] The third determination module is used to determine the actual correction pulse length at the current moment according to the deviation correction pulse length and the pulse length gain coefficient at the current moment, and adjust the guide vane opening of the hydropower unit based on the actual correction pulse length, thereby correcting the primary frequency regulation deviation of the hydropower unit.

[0052] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0053] The present application proposes a method and system for correcting the primary frequency regulation deviation of a hydropower unit under an opening regulation mode, wherein the method comprises: obtaining the grid frequency, the rated frequency, the actual output value of the hydropower unit and the target adjustment ratio of the primary frequency regulation at the current moment, and determining the frequency deviation at the current moment based on the grid frequency and the rated frequency at the current moment; determining the target adjustment amount of the primary frequency regulation at the current moment according to the frequency deviation at the current moment, and determining the primary frequency regulation reference amount, and then determining the target output value of the hydropower unit at the current moment according to the target adjustment amount of the primary frequency regulation and the primary frequency regulation reference amount; the hydropower unit at the current moment When the unit is in primary frequency regulation, the actual output value of the hydropower unit is not equal to the target output value of the hydropower unit and the first preset condition is met, the deviation correction pulse length and pulse length gain coefficient at the current moment are determined according to the actual output value of the hydropower unit, the target adjustment amount of the primary frequency regulation, the primary frequency regulation reference amount, and the target adjustment ratio of the primary frequency regulation; the actual correction pulse length at the current moment is determined according to the deviation correction pulse length and pulse length gain coefficient at the current moment, and the guide vane opening of the hydropower unit is adjusted based on the actual correction pulse length, thereby correcting the primary frequency regulation deviation of the hydropower unit. The technical solution proposed in this application corrects the primary frequency regulation by issuing a correction pulse, thereby improving the regulation performance of the primary frequency regulation and ensuring the stability of the power grid frequency.

[0054] 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

[0055] 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:

[0056] Figure 1 It is a flow chart of a method for correcting primary frequency regulation deviation of a hydropower unit in an opening regulation mode according to an embodiment of the present application;

[0057] Figure 2 A frequency deviation calculation trend diagram of a primary frequency regulation according to an embodiment of the present application as a function of the power grid frequency;

[0058] Figure 3 A flowchart of a closed-loop adjustment target of a computer group output provided according to an embodiment of the present application;

[0059] Figure 4 A calculation logic diagram of a guide vane opening not being in an adjustment process provided according to an embodiment of the present application;

[0060] Figure 5 A schematic diagram of the length of a primary frequency modulation correction pulse provided according to an embodiment of the present application;

[0061] Figure 6 This is a structural diagram of a primary frequency regulation deviation correction system for a hydropower unit in an opening regulation mode provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0062] 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.

[0063] The present application proposes a method and system for correcting the primary frequency regulation deviation of a hydropower unit under an opening regulation mode, wherein the method comprises: obtaining the grid frequency, the rated frequency, the actual output value of the hydropower unit and the target adjustment ratio of the primary frequency regulation at the current moment, and determining the frequency deviation at the current moment based on the grid frequency and the rated frequency at the current moment; determining the target adjustment amount of the primary frequency regulation at the current moment according to the frequency deviation at the current moment, and determining the primary frequency regulation reference amount, and then determining the target output value of the hydropower unit at the current moment according to the target adjustment amount of the primary frequency regulation and the primary frequency regulation reference amount; the hydropower unit at the current moment When the unit is in primary frequency regulation, the actual output value of the hydropower unit is not equal to the target output value of the hydropower unit and the first preset condition is met, the deviation correction pulse length and pulse length gain coefficient at the current moment are determined according to the actual output value of the hydropower unit, the target adjustment amount of the primary frequency regulation, the primary frequency regulation reference amount, and the target adjustment ratio of the primary frequency regulation; the actual correction pulse length at the current moment is determined according to the deviation correction pulse length and pulse length gain coefficient at the current moment, and the guide vane opening of the hydropower unit is adjusted based on the actual correction pulse length, thereby correcting the primary frequency regulation deviation of the hydropower unit. The technical solution proposed in this application corrects the primary frequency regulation by issuing a correction pulse, thereby improving the regulation performance of the primary frequency regulation and ensuring the stability of the power grid frequency.

[0064] The following describes a method and system for correcting the primary frequency regulation deviation of a hydropower unit in an opening regulation mode according to an embodiment of the present application with reference to the accompanying drawings.

[0065] Embodiment 1

[0066] Figure 1 The flowchart of a method for correcting a primary frequency regulation deviation of a hydropower unit in an opening regulation mode according to an embodiment of the present application is as follows. Figure 1 As shown, the method includes:

[0067] Step 1: Obtain the grid frequency, rated frequency, actual output value of the hydropower unit and primary frequency regulation target adjustment ratio at the current moment, and determine the frequency deviation at the current moment based on the grid frequency and rated frequency at the current moment.

[0068] In an embodiment of the present disclosure, determining the frequency deviation at the current moment based on the grid frequency and the rated frequency at the current moment includes:

[0069] When the grid frequency is greater than the rated frequency, Δf=min[0, f n -f+f d ], where Δf is the frequency deviation, f n is the rated frequency, f is the grid frequency, f d It is the threshold value of hydropower primary frequency regulation action;

[0070] When the grid frequency is less than the rated frequency, Δf=max[0,f n -f-f d ];

[0071] When the grid frequency is equal to the rated frequency, Δf=0.

[0072] For example, when the grid frequency is greater than the rated frequency, the rated frequency f n The frequency deviation Δf is 0 when the grid frequency is greater than 50Hz and less than 50.05Hz, and the threshold value of the primary frequency regulation of hydropower is 0.05Hz. Then Δf = min[0, 50.05-f], that is, when the grid frequency is greater than 50Hz and less than 50.05Hz, the frequency deviation Δf is 0, and when the grid frequency is greater than 50.05Hz, Δf is 50.05Hz minus the grid frequency.

[0073] When the grid frequency is less than the rated frequency, the frequency deviation Δf=max[0, f n -f-f d ], this embodiment takes China Southern Power Grid as an example, then Δf=max[0,49.95-f], that is, when the grid frequency is less than 50 Hz and greater than 49.95 Hz, the frequency deviation Δf is 0, and when the grid frequency is less than 49.95 Hz, Δf is 49.95 Hz minus the grid frequency;

[0074] When the grid frequency is equal to the rated frequency, the frequency deviation Δf=0.

[0075] In general, the frequency deviation Δf changes with the grid frequency as follows: Figure 2shown.

[0076] Step 2: Determine the primary frequency regulation target adjustment amount at the current moment and determine the primary frequency regulation reference amount according to the frequency deviation at the current moment, and then determine the output target value of the hydropower unit at the current moment according to the primary frequency regulation target adjustment amount and the primary frequency regulation reference amount.

[0077] In the embodiment of the present disclosure, determining the target frequency modulation amount at the current moment according to the frequency deviation at the current moment includes:

[0078] Obtaining a primary frequency regulation ratio adjustment coefficient, and taking the product of the frequency deviation at the current moment, the rated capacity of the hydropower unit and the primary frequency regulation ratio adjustment coefficient as the primary frequency regulation target adjustment amount at the current moment;

[0079] For example, if the frequency modulation function is activated, the target frequency modulation amount p f =Q×Δf×k f , where Q is the rated capacity of the unit. In this embodiment, it is assumed that the rated capacity of the unit Q is 200MW, then the primary frequency regulation target adjustment amount = 200 × Δf × 0.5 = Δf × 100;

[0080] If the primary frequency modulation function is exited, the primary frequency modulation target adjustment amount p f is equal to 0.

[0081] The step of determining a primary frequency modulation reference value comprises:

[0082] If the hydropower unit is in the secondary frequency regulation process, the output setting value of the hydropower unit corresponding to the current secondary frequency regulation instruction is used as the primary frequency regulation reference value;

[0083] If the hydropower unit is not in the process of secondary frequency regulation, the actual output value of the hydropower unit at the start time of the primary frequency regulation action is used as the primary frequency regulation reference value;

[0084] If the hydropower unit receives a secondary frequency regulation instruction during the primary frequency regulation action, the output setting value of the hydropower unit corresponding to the secondary frequency regulation instruction is used as the primary frequency regulation reference value.

[0085] For example, S2100) a frequency modulation reference quantity p b The default initial quantity is equal to the unit output setting value p s ;

[0086] S2200) When the unit output setting value p s When the frequency modulation reference value p changes, b Modified to the changed p s ;

[0087] S2300) determines whether the unit is in the secondary frequency regulation process:

[0088] S2310) setting the flag α in the secondary frequency modulation process, where the initial value of α is 0;

[0089] S2320) Setting timers T1, T2 and time thresholds t1, t2;

[0090] S2330) When the unit output setting value p s When a change occurs, the flag α in the secondary frequency modulation process is set to 1, and the timer T1 is reset and restarted;

[0091] S2340) When the absolute value of the deviation between the actual output value of the unit and the set output value of the unit is greater than the output regulation dead zone, stop and reset the timer T2;

[0092] S2350) When the absolute value of the deviation between the actual output value of the unit and the set output value of the unit is less than or equal to the output regulation dead zone, the timer T2 starts counting;

[0093] S2360) If T1 is greater than or equal to t1 and T2 is greater than or equal to t2, the identifier α during the secondary frequency modulation process is set to 0, otherwise the identifier α during the secondary frequency modulation process is maintained unchanged.

[0094] According to S2300, if the set value of the hydropower unit output changes for more than a certain period of time and the actual output value of the unit is stable within the set value adjustment dead zone, it is considered that the unit is not in the secondary frequency regulation process, otherwise it is considered that the unit is in the secondary frequency regulation process.

[0095] S2400) When the primary frequency modulation target adjustment amount p f When it changes from 0 to non-0, a judgment is made, including:

[0096] S2410) If the secondary frequency modulation process identifier α is equal to 0, the primary frequency modulation reference value p b Modify to the current actual output value p of the unit;

[0097] S2420) If the flag α is equal to 1 during the secondary frequency modulation process, the primary frequency modulation reference value p is maintained. b constant.

[0098] S2500) When the frequency modulation target adjustment amount p f When it changes from non-zero to zero, the primary frequency modulation reference value p b Modify to the unit output setting value p s .

[0099] S2600) When the flag α changes from 0 to 1 during the secondary frequency modulation process, the primary frequency modulation reference value p b Modify to the unit output setting value p s;

[0100] S2700) The closed-loop regulation target of the unit output is the output target value p of the hydropower unit t =p b +p f , p t It is the closed-loop regulation target of the unit output, such as Figure 3 shown.

[0101] It should be noted that if the unit is in the secondary frequency regulation process during the primary frequency regulation action, the unit output set value shall always be used as the primary frequency regulation reference value; if the unit is not in the secondary frequency regulation process during the primary frequency regulation action, the unit output actual value at the starting time of the primary frequency regulation action shall be used as the primary frequency regulation reference value; if a new secondary frequency regulation instruction is received during the primary frequency regulation action, the new unit output set value shall be used as the primary frequency regulation reference value.

[0102] Step 3: When the hydropower unit is currently in primary frequency regulation, the actual output value of the hydropower unit is not equal to the target output value of the hydropower unit and the first preset condition is met, the deviation correction pulse length and pulse length gain coefficient at the current moment are determined according to the actual output value of the hydropower unit, the primary frequency regulation target adjustment amount, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment ratio.

[0103] In the embodiment of the present disclosure, the first preset condition includes:

[0104] The deviation between the actual output value of the hydropower unit and the target output value of the hydropower unit is less than the regulation dead zone;

[0105] The guide vane opening of the hydroelectric unit is not in the adjustment process, and the duration is greater than a preset first time length.

[0106] For example, the monitoring system corrects the frequency deviation of the generator set once when the following conditions are met, and the conditions include:

[0107] The unit is in the process of primary frequency regulation, that is, the primary frequency regulation target adjustment amount pf is not equal to 0;

[0108] The actual output value of the unit is not equal to the target output value of the unit, and the deviation between the two is less than the regulation dead zone;

[0109] The guide vane opening is not in the adjustment process and continues to exceed the time threshold t3. The calculation logic is as follows Figure 4 As shown, including:

[0110] Set timer T3;

[0111] When the guide vane opening output by the speed governor is not in the adjustment process, timer T3 starts timing;

[0112] When the guide vane opening output by the speed regulator is in the adjustment process, stop and reset the timer T3;

[0113] If T3 is greater than or equal to t3, it is considered that the guide vane opening is not in the adjustment process and continues to exceed the time threshold t3.

[0114] It should be noted that before performing deviation correction, it is necessary to determine whether the speed governor is in the process of adjusting the guide vane opening. If so, stop the deviation correction, and wait until the guide vane opening is not in the process of adjusting, and then perform the deviation correction;

[0115] The speed governor determines whether the guide vane opening is in the adjustment process and sends the judgment result to the monitoring system, including:

[0116] S3100) The absolute value of the deviation between the target opening of the guide vanes and the actual opening of the guide vanes of the governor computer group;

[0117] S3200) The speed governor compares the absolute value of the deviation obtained by S3100 with the dead zone of the guide vane opening adjustment, including:

[0118] S3210) if the absolute value of the deviation obtained in S3100 is greater than or equal to the dead zone of guide vane opening adjustment, output the switch value of the guide vane opening in the adjustment process to the monitoring system;

[0119] S3220) If the absolute value of the deviation obtained in S3200 is smaller than the dead zone of the guide vane opening adjustment, the switch value indicating that the guide vane opening is not in the adjustment process is output to the monitoring system.

[0120] It can prevent the monitoring system from correcting the primary frequency modulation which is still in the adjustment process.

[0121] In the embodiment of the present disclosure, step 3 specifically includes:

[0122] 3-1. Determine the deviation between the primary frequency regulation target adjustment amount and the primary frequency regulation actual adjustment amount at the current moment according to the primary frequency regulation target adjustment amount, the actual output value of the hydropower unit and the primary frequency regulation reference amount;

[0123] Among them, the above 3-1 includes:

[0124] Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation value;

[0125] The difference between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation is determined, and the difference is used as the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation.

[0126] 3-2. Determine the deviation between the actual primary frequency regulation ratio and the primary frequency regulation target regulation ratio at the current moment according to the primary frequency regulation target regulation ratio, the actual output value of the hydropower unit, the primary frequency regulation reference amount, and the primary frequency regulation target regulation amount;

[0127] Among them, 3-2 includes:

[0128] Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation adjustment value;

[0129] The ratio of the actual adjustment amount of the primary frequency regulation to the target adjustment amount of the primary frequency regulation is used as the actual adjustment ratio of the primary frequency regulation;

[0130] The difference between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation is determined, and the difference is used as the deviation between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation.

[0131] For example, a frequency modulation target adjustment ratio γ is set, where γ is greater than 0 and less than or equal to 1. In this embodiment, it is assumed that the frequency modulation target adjustment ratio γ is set to 1.

[0132] Calculate the actual adjustment ratio of primary frequency modulation Δγ, Δγ=Δp f ÷p f ;

[0133] Calculate the deviation Δγ between the actual adjustment ratio of primary frequency regulation and the target adjustment ratio of primary frequency regulation, Δγ=Δp f ÷p f .

[0134] 3-3. Determine the deviation correction pulse length at the current moment according to the deviation between the target frequency modulation adjustment amount at the current moment and the actual frequency modulation adjustment amount at the current moment;

[0135] The calculation formula of the deviation correction pulse length is as follows:

[0136] v t =Δp t ×u

[0137] In the formula, v t is the deviation correction pulse length at the current time t, Δp t is the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation, and u is the preset basic pulse length.

[0138] 3-4. Determine the pulse length gain coefficient at the current moment according to the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation.

[0139] Among them, 3-4 includes:

[0140] Obtaining a preset gain coefficient group and a proportional threshold corresponding to the gain coefficient group, wherein the number of gain coefficients in the preset gain coefficient group is N, the number of proportional thresholds is N-1, and the proportional thresholds are arranged from small to large;

[0141] If the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation at the current moment is less than or equal to the first ratio threshold, the first gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment;

[0142] If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the last ratio threshold, the last gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment;

[0143] If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the m-1th ratio threshold and less than or equal to the mth ratio threshold, the mth gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment.

[0144] Step 4: Determine the actual deviation correction pulse length at the current moment according to the deviation correction pulse length and the pulse length gain coefficient at the current moment, adjust the guide vane opening of the hydropower unit based on the actual deviation correction pulse length, and thereby correct the primary frequency regulation deviation of the hydropower unit.

[0145] In the embodiment of the present disclosure, step 4 specifically includes:

[0146] When the pulse length gain coefficient is equal to zero, the actual correction pulse length at the current moment is equal to zero;

[0147] When the pulse length gain coefficient is not equal to zero:

[0148] If the current deviation correction pulse length is greater than zero, then use the formula Δv t =v t ×θ t ×β+σ, determine the actual deviation correction pulse length at the current moment, and increase the guide vane opening to correct the deviation based on the actual deviation correction pulse length;

[0149] If the current deviation correction pulse length is less than zero, then use the formula Δv t =v t ×θ t ×β-σ, determine the actual deviation correction pulse length at the current moment, and reduce the guide vane opening to perform deviation correction based on the actual deviation correction pulse length;

[0150] Where Δv t is the actual correction pulse length at the current time t, v t is the deviation correction pulse length at the current time t, θ t is the pulse length gain coefficient at the current time t, β is the associated parameter, and σ is the preset first parameter;

[0151] It should be noted that the actual adjustment amount Δp of a frequency modulation is determined f The target adjustment amount p of the primary frequency modulation f Whether the directions are consistent, if the directions are inconsistent, the first frequency modulation direction opposite associated parameter β is set to a number greater than 1, otherwise it is set to 1. In this embodiment, it is assumed that when the actual adjustment amount of the first frequency modulation is opposite to the target adjustment amount, β is 1.3.

[0152] For example, S5100) according to the operation experience and test data, the basic pulse length u is set, where u is the guide vane opening increase pulse length issued by the monitoring system corresponding to the increase of 1MW output of the unit in the opening adjustment mode, or the guide vane opening decrease pulse length issued by the monitoring system corresponding to the decrease of 1MW output of the unit in the opening adjustment mode. In this embodiment, it is assumed that the basic pulse length u is equal to 1;

[0153] S5200) Calculate the deviation correction pulse length v, v = Δp × u;

[0154] S5300) Calculate the pulse length gain coefficient θ, including:

[0155] S5310) setting a group of n gain coefficients, where n is an integer variable set manually, and the gain coefficients are arranged from small to large, and the first smallest gain coefficient is set to 0;

[0156] In this embodiment, a set of 4 gain coefficients are set, which are 0, 0.2, 0.4, and 0.6 respectively;

[0157] S5320) setting a group of n-1 ratio thresholds, the ratio thresholds are arranged from small to large, and in this embodiment, three ratio thresholds are set, namely 20%, 50%, and 80%;

[0158] S5330) comparing the deviation Δd between the actual adjustment ratio of the primary frequency modulation and the target adjustment ratio of the primary frequency modulation with a set of ratio thresholds set in S5320, including:

[0159] S5331) when Δd is less than or equal to the first proportional threshold, the pulse length gain coefficient takes the first gain coefficient set in S5310;

[0160] S5332) when Δd is greater than the last proportional threshold, the pulse length gain coefficient takes the last gain coefficient set in S5310;

[0161] S5333) When Δd is greater than the m-1th proportional threshold and less than or equal to the mth proportional threshold, the pulse length gain coefficient takes the mth gain coefficient set in S5310.

[0162] According to the gain coefficient and ratio threshold described above in this embodiment, when the actual adjustment ratio of a frequency modulation is more than 80%, the gain coefficient is 0; when it is between 80% and 50%, the gain coefficient is 0.2; when it is between 50% and 20%, the gain coefficient is 0.4; when it is less than 25%, or the adjustment direction is opposite (i.e., when the adjustment ratio is less than 0), the gain coefficient is 0.6.

[0163] S5400) Calculate the actual correction pulse length Δv, including:

[0164] S5410) If θ is equal to 0, then Δv=0;

[0165] S5420) If θ is not equal to 0, then:

[0166] S5421) if v is greater than 0, then Δv = v×θ×β+σ, where σ is a very small value set manually to ensure that the correction pulse can take effect;

[0167] S5422) If v is less than 0, then Δv = v×θ×β-σ.

[0168] According to the above assumptions of the embodiment, if the primary frequency modulation target adjustment amount is to increase the active power by 30MW, then under different primary frequency modulation actual adjustment amounts, the deviation correction pulse length is as follows: Figure 5 shown.

[0169] S5500) If v is greater than 0, a guide vane opening correction pulse with a length of |Δv| is sent to the speed governor;

[0170] S5600) If v is less than 0, a guide vane opening reduction correction pulse of |Δv| length is sent to the speed regulator.

[0171] The technical solution provided in this embodiment has the following advantages:

[0172] 1. It is suitable for hydropower stations or hydropower units that use the governor opening mode to adjust the unit output. When the primary frequency regulation fails to achieve the expected effect, it can correct the primary frequency regulation by issuing a correction pulse to improve the regulation performance of the primary frequency regulation, while avoiding excessive gain of the primary frequency regulation when the regulation effect meets the standard, thereby effectively ensuring the stability of the power grid frequency;

[0173] 2. Different adjustment mechanisms are designed for different working conditions. When the primary frequency regulation and the secondary frequency regulation are in action at the same time, in order to ensure the availability of the function, the primary frequency regulation target adjustment amount plus the secondary frequency regulation output setting value is used as the actual adjustment target; when the primary frequency regulation is in action alone, in order to ensure the adjustment effect of the primary frequency regulation, the actual output value at the starting time of the primary frequency regulation plus the primary frequency regulation target adjustment amount is used as the actual adjustment target.

[0174] In summary, the present embodiment proposes a method for correcting the primary frequency regulation deviation of a hydropower unit in an opening regulation mode, which corrects the primary frequency regulation by issuing a correction pulse, thereby improving the regulation performance of the primary frequency regulation and ensuring the stability of the grid frequency.

[0175] Embodiment 2

[0176] Figure 6 The structure diagram of a primary frequency regulation deviation correction system for a hydropower unit in an opening regulation mode according to an embodiment of the present application is shown as follows: Figure 6 As shown, the system comprises:

[0177] The acquisition module 100 is used to acquire the grid frequency, the rated frequency, the actual output value of the hydropower unit and the primary frequency regulation target adjustment ratio at the current moment, and determine the frequency deviation at the current moment based on the grid frequency and the rated frequency at the current moment;

[0178] The determining the frequency deviation at the current moment based on the grid frequency at the current moment and the rated frequency includes:

[0179] When the grid frequency is greater than the rated frequency, Δf=min[0, f n -f+f d ], where Δf is the frequency deviation, f n is the rated frequency, f is the grid frequency, f d It is the threshold value of hydropower primary frequency regulation action;

[0180] When the grid frequency is less than the rated frequency, Δf=max[0,f n -f-f d ];

[0181] When the grid frequency is equal to the rated frequency, Δf=0.

[0182] The first determination module 200 is used to determine the primary frequency regulation target adjustment amount at the current moment according to the frequency deviation at the current moment, and determine the primary frequency regulation reference amount, and then determine the output target value of the hydropower unit at the current moment according to the primary frequency regulation target adjustment amount and the primary frequency regulation reference amount;

[0183] The second determination module 300 is used to determine the deviation correction pulse length and pulse length gain coefficient at the current moment according to the actual output value of the hydropower unit, the primary frequency regulation target adjustment amount, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment ratio when the hydropower unit is in primary frequency regulation at the current moment, the actual output value of the hydropower unit is not equal to the output target value of the hydropower unit and the first preset condition is met;

[0184] Wherein, the first preset condition includes:

[0185] The deviation between the actual output value of the hydropower unit and the target output value of the hydropower unit is less than the regulation dead zone;

[0186] The guide vane opening of the hydroelectric unit is not in the adjustment process, and the duration is greater than a preset first time length.

[0187] The third determination module 400 is used to determine the actual correction pulse length at the current moment according to the deviation correction pulse length and the pulse length gain coefficient at the current moment, and adjust the guide vane opening of the hydropower unit based on the actual correction pulse length, thereby correcting the primary frequency regulation deviation of the hydropower unit.

[0188] In the embodiment of the present disclosure, the first determining module 200 is further configured to:

[0189] The primary frequency regulation ratio adjustment coefficient is obtained, and the product of the frequency deviation at the current moment, the rated capacity of the hydropower unit and the primary frequency regulation ratio adjustment coefficient is used as the primary frequency regulation target adjustment amount at the current moment.

[0190] The first determining module 200 is further configured to:

[0191] If the hydropower unit is in the secondary frequency regulation process, the output setting value of the hydropower unit corresponding to the current secondary frequency regulation instruction is used as the primary frequency regulation reference value;

[0192] If the hydropower unit is not in the process of secondary frequency regulation, the actual output value of the hydropower unit at the start time of the primary frequency regulation action is used as the primary frequency regulation reference value;

[0193] If the hydropower unit receives a secondary frequency regulation instruction during the primary frequency regulation action, the output setting value of the hydropower unit corresponding to the secondary frequency regulation instruction is used as the primary frequency regulation reference value.

[0194] In the embodiment of the present disclosure, the second determining module 300 is further configured to:

[0195] Determine the deviation between the primary frequency regulation target adjustment amount and the primary frequency regulation actual adjustment amount at the current moment according to the primary frequency regulation target adjustment amount, the actual output value of the hydropower unit and the primary frequency regulation reference amount;

[0196] Determine the deviation between the actual primary frequency regulation adjustment ratio and the primary frequency regulation target adjustment ratio at the current moment according to the primary frequency regulation target adjustment ratio, the actual output value of the hydropower unit, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment amount;

[0197] Determining the deviation correction pulse length at the current moment according to the deviation between the primary frequency modulation target adjustment amount at the current moment and the primary frequency modulation actual adjustment amount;

[0198] The calculation formula of the deviation correction pulse length is as follows:

[0199] v t =Δp t ×u

[0200] In the formula, v t is the deviation correction pulse length at the current time t, Δp t is the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation, and u is the preset basic pulse length.

[0201] The pulse length gain coefficient at the current moment is determined according to the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation.

[0202] Furthermore, the second determining module 300 is further configured to:

[0203] Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation value;

[0204] The difference between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation is determined, and the difference is used as the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation.

[0205] Furthermore, the second determining module 300 is further configured to:

[0206] Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation value;

[0207] The ratio of the actual adjustment amount of the primary frequency regulation to the target adjustment amount of the primary frequency regulation is used as the actual adjustment ratio of the primary frequency regulation;

[0208] The difference between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation is determined, and the difference is used as the deviation between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation.

[0209] In the embodiment of the present disclosure, the second determining module 300 is further configured to:

[0210] Obtaining a preset gain coefficient group and a proportional threshold corresponding to the gain coefficient group, wherein the number of gain coefficients in the preset gain coefficient group is N, the number of proportional thresholds is N-1, and the proportional thresholds are arranged from small to large;

[0211] If the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation at the current moment is less than or equal to the first ratio threshold, the first gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment;

[0212] If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the last ratio threshold, the last gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment;

[0213] If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the m-1th ratio threshold and less than or equal to the mth ratio threshold, the mth gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment.

[0214] In the embodiment of the present disclosure, the third determining module 400 is further configured to:

[0215] When the pulse length gain coefficient is equal to zero, the actual correction pulse length at the current moment is equal to zero;

[0216] When the pulse length gain coefficient is not equal to zero:

[0217] If the current deviation correction pulse length is greater than zero, then use the formula Δv t =v t ×θ t ×β+σ, determine the actual deviation correction pulse length at the current moment, and increase the guide vane opening to correct the deviation based on the actual deviation correction pulse length;

[0218] If the current deviation correction pulse length is less than zero, then use the formula Δv t =v t ×θ t ×β-σ, determine the actual deviation correction pulse length at the current moment, and reduce the guide vane opening to perform deviation correction based on the actual deviation correction pulse length;

[0219] Where Δv t is the actual correction pulse length at the current time t, v t is the deviation correction pulse length at the current time t, θ tis the pulse length gain coefficient at the current time t, β is the associated parameter, and σ is the preset first parameter.

[0220] In summary, the present embodiment proposes a primary frequency regulation deviation correction system for a hydropower unit in an opening regulation mode, which corrects the primary frequency regulation by issuing a correction pulse, thereby improving the regulation performance of the primary frequency regulation and ensuring the stability of the grid frequency.

[0221] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0222] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0223] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for correcting the primary frequency regulation deviation of a hydropower unit in an opening adjustment mode, characterized in that: The method comprises: Obtaining the grid frequency, rated frequency, actual output value of the hydropower unit and primary frequency regulation target adjustment ratio at the current moment, and determining the frequency deviation at the current moment based on the grid frequency and rated frequency at the current moment; Determine the primary frequency regulation target adjustment amount at the current moment according to the frequency deviation at the current moment, and determine the primary frequency regulation reference amount, and then determine the output target value of the hydropower unit at the current moment according to the primary frequency regulation target adjustment amount and the primary frequency regulation reference amount; When the hydropower unit at the current moment is in primary frequency regulation, the actual output value of the hydropower unit is not equal to the target output value of the hydropower unit and the first preset condition is met, the deviation correction pulse length and the pulse length gain coefficient at the current moment are determined according to the actual output value of the hydropower unit, the target adjustment amount of the primary frequency regulation, the primary frequency regulation reference amount, and the target adjustment ratio of the primary frequency regulation; The actual deviation correction pulse length at the current moment is determined according to the deviation correction pulse length and the pulse length gain coefficient at the current moment, and the guide vane opening of the hydropower unit is adjusted based on the actual deviation correction pulse length, thereby correcting the primary frequency regulation deviation of the hydropower unit.

2. The method according to claim 1, characterized in that The determining the frequency deviation at the current moment based on the grid frequency at the current moment and the rated frequency includes: When the grid frequency is greater than the rated frequency, Δf=min[0, f n -f+f d ], where Δf is the frequency deviation, f n is the rated frequency, f is the grid frequency, f d It is the threshold value of hydropower primary frequency regulation action; When the grid frequency is less than the rated frequency, Δf=max[0,f n -f-f d ]; When the grid frequency is equal to the rated frequency, Δf=0.

3. The method according to claim 2, characterized in that The determining of a target frequency modulation adjustment amount at the current moment according to the frequency deviation at the current moment includes: Obtaining a primary frequency regulation ratio adjustment coefficient, and taking the product of the frequency deviation at the current moment, the rated capacity of the hydropower unit and the primary frequency regulation ratio adjustment coefficient as the primary frequency regulation target adjustment amount at the current moment; The step of determining a primary frequency modulation reference value comprises: If the hydropower unit is in the secondary frequency regulation process, the output setting value of the hydropower unit corresponding to the current secondary frequency regulation instruction is used as the primary frequency regulation reference value; If the hydropower unit is not in the process of secondary frequency regulation, the actual output value of the hydropower unit at the start time of the primary frequency regulation action is used as the primary frequency regulation reference value; If the hydropower unit receives a secondary frequency regulation instruction during the primary frequency regulation action, the output setting value of the hydropower unit corresponding to the secondary frequency regulation instruction is used as the primary frequency regulation reference value.

4. The method according to claim 3, characterized in that The first preset condition includes: The deviation between the actual output value of the hydropower unit and the target output value of the hydropower unit is less than the regulation dead zone; The guide vane opening of the hydroelectric unit is not in the adjustment process, and the duration is greater than a preset first time length.

5. The method according to claim 4, characterized in that The method of determining the deviation correction pulse length and the pulse length gain coefficient at the current moment according to the actual output value of the hydropower unit, the primary frequency regulation target adjustment amount, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment ratio includes: Determine the deviation between the primary frequency regulation target adjustment amount and the primary frequency regulation actual adjustment amount at the current moment according to the primary frequency regulation target adjustment amount, the actual output value of the hydropower unit and the primary frequency regulation reference amount; Determine the deviation between the actual primary frequency regulation adjustment ratio and the primary frequency regulation target adjustment ratio at the current moment according to the primary frequency regulation target adjustment ratio, the actual output value of the hydropower unit, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment amount; Determining the deviation correction pulse length at the current moment according to the deviation between the primary frequency modulation target adjustment amount at the current moment and the primary frequency modulation actual adjustment amount; The pulse length gain coefficient at the current moment is determined according to the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation.

6. The method according to claim 5, characterized in that The step of determining the deviation between the primary frequency regulation target adjustment amount and the primary frequency regulation actual adjustment amount at the current moment according to the primary frequency regulation target adjustment amount, the actual output value of the hydropower unit and the primary frequency regulation reference amount includes: Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation adjustment value; Determine the difference between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation, and use the difference as the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation; The method of determining the deviation between the primary frequency regulation target adjustment ratio and the primary frequency regulation actual adjustment ratio at the current moment according to the primary frequency regulation target adjustment ratio, the actual output value of the hydropower unit, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment amount includes: Determine the difference between the actual output value of the hydropower unit and the primary frequency regulation reference value, and use the difference as the actual primary frequency regulation adjustment value; The ratio of the actual adjustment amount of the primary frequency regulation to the target adjustment amount of the primary frequency regulation is used as the actual adjustment ratio of the primary frequency regulation; The difference between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation is determined, and the difference is used as the deviation between the target adjustment ratio of the primary frequency modulation at the current moment and the actual adjustment ratio of the primary frequency modulation.

7. The method according to claim 6, characterized in that The calculation formula of the deviation correction pulse length is as follows: v t =Δp t ×u In the formula, v t is the deviation correction pulse length at the current time t, Δp t is the deviation between the target adjustment amount of the primary frequency modulation at the current moment and the actual adjustment amount of the primary frequency modulation, and u is the preset basic pulse length.

8. The method according to claim 7, characterized in that The step of determining the pulse length gain coefficient at the current moment according to the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation at the current moment comprises: Obtaining a preset gain coefficient group and a proportional threshold corresponding to the gain coefficient group, wherein the number of gain coefficients in the preset gain coefficient group is N, the number of proportional thresholds is N-1, and the proportional thresholds are arranged from small to large; If the deviation between the actual adjustment ratio of the primary frequency modulation at the current moment and the target adjustment ratio of the primary frequency modulation at the current moment is less than or equal to the first ratio threshold, the first gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment; If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the last ratio threshold, the last gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment; If the deviation between the actual frequency modulation adjustment ratio and the target frequency modulation adjustment ratio at the current moment is greater than the m-1th ratio threshold and less than or equal to the mth ratio threshold, the mth gain coefficient in the gain coefficient group is used as the pulse length gain coefficient at the current moment.

9. The method according to claim 7, characterized in that The actual deviation correction pulse length at the current moment is determined according to the deviation correction pulse length at the current moment and the pulse length gain coefficient, and the guide vane opening of the hydropower unit is adjusted based on the actual deviation correction pulse length, thereby correcting the primary frequency modulation deviation of the hydropower unit, including: When the pulse length gain coefficient is equal to zero, the actual correction pulse length at the current moment is equal to zero; When the pulse length gain coefficient is not equal to zero: If the current deviation correction pulse length is greater than zero, then use the formula Δv t =v t ×θ t ×β+σ, determine the actual deviation correction pulse length at the current moment, and increase the guide vane opening to correct the deviation based on the actual deviation correction pulse length; If the current deviation correction pulse length is less than zero, then use the formula Δv t =v t ×θ t ×β-σ, determine the actual deviation correction pulse length at the current moment, and reduce the guide vane opening to perform deviation correction based on the actual deviation correction pulse length; Where Δv t is the actual correction pulse length at the current time t, v t is the deviation correction pulse length at the current time t, θ t is the pulse length gain coefficient at the current time t, β is the associated parameter, and σ is the preset first parameter.

10. A primary frequency regulation deviation correction system for a hydropower unit in an opening adjustment mode, characterized in that: The system comprises: An acquisition module is used to acquire the grid frequency, rated frequency, actual output value of the hydropower unit and the primary frequency regulation target adjustment ratio at the current moment, and determine the frequency deviation at the current moment based on the grid frequency and rated frequency at the current moment; A first determination module is used to determine the primary frequency regulation target adjustment amount at the current moment according to the frequency deviation at the current moment, and determine the primary frequency regulation reference amount, and then determine the output target value of the hydropower unit at the current moment according to the primary frequency regulation target adjustment amount and the primary frequency regulation reference amount; The second determination module is used to determine the deviation correction pulse length and pulse length gain coefficient at the current moment according to the actual output value of the hydropower unit, the primary frequency regulation target adjustment amount, the primary frequency regulation reference amount, and the primary frequency regulation target adjustment ratio when the hydropower unit is in primary frequency regulation at the current moment, the actual output value of the hydropower unit is not equal to the output target value of the hydropower unit and the first preset condition is met; The third determination module is used to determine the actual correction pulse length at the current moment according to the deviation correction pulse length and the pulse length gain coefficient at the current moment, and adjust the guide vane opening of the hydropower unit based on the actual correction pulse length, thereby correcting the primary frequency regulation deviation of the hydropower unit.

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