Active power control method, system and equipment for hydroelectric generating set

Abstract

The invention relates to the technical field of hydroelectric generating set active control, in particular to a hydroelectric generating set active control method, system and equipment, a guide vane opening degree-active function is constructed through experimental data, and when active control is conducted on a hydroelectric generating set, a guide vane opening degree feed-forward value is obtained through current parameters of the hydroelectric generating set and the guide vane opening degree-active function; the method comprises the following steps of: calculating a water head correction amount and a frequency correction amount, finally determining an optimized guide vane opening analog quantity by combining a guide vane opening-active power function, and finally adjusting the guide vane opening, thereby realizing high-speed, high-precision and low-delay active power adjustment. And actual operation requirements are met.

Description

Technical Field

[0001] The present invention relates to the technical field of active power control of hydroelectric generator sets, and in particular to a method, system and equipment for active power control of hydroelectric generator sets. Background Art

[0002] At present, most domestic hydropower stations adopt a dual closed-loop mode of "monitoring power closed-loop + governor opening closed-loop" to regulate the active power of the turbine units. That is, the control unit of each unit sends an opening increase or decrease pulse instruction to the governor in real time according to the deviation between the actual active power of the unit and the target value of the active power regulation. The governor modifies the given value of the guide vane opening according to the received increase or decrease pulse instruction to complete the active power regulation of the unit.

[0003] With the development of my country's power technology, the requirements for power regulation and frequency control of hydro-turbine units are becoming increasingly higher. The existing dual closed-loop mode of "monitoring power closed-loop + governor opening closed-loop" has problems of low control accuracy and high delay, and cannot meet the power regulation needs of existing hydro-turbine units. Summary of the Invention

[0004] The purpose of the present invention is to provide a method, system and equipment for controlling the active power of a hydropower unit to solve the technical problems existing in the prior art.

[0005] The present invention solves the above-mentioned technical problems by: A method for controlling active power of a hydroelectric generator set comprises the following steps: S1. Construct guide vane opening-work function; S2. Obtain the load command and obtain the guide vane opening feedforward value according to the current parameters of the hydropower unit and the guide vane opening-work power function; S3. Determine the water head correction amount based on the current parameters and load instructions of the hydropower unit; S4. Determine the frequency correction amount based on the current parameters and load instructions of the hydropower unit; S5. Determine the guide vane opening analog value according to the load instruction, the head correction value, the frequency correction value and the guide vane opening-work function.

[0006] It is further defined that step S1 includes the following steps: S1.1. Under rated water head, set the guide vane opening L a =ax+L0, where x is the gradient value, a is the ath test, and L0 is the no-load opening; S1.2, according to the current guide vane opening L a , record the active power P of the hydropower unit at the corresponding moment a ; S1.3, for (L a-1 , P a-1 ) and (La , P a ) and perform linear interpolation on the two points to obtain the guide vane opening-work function applicable to this section: P= (L L a-1 )+P a-1 Among them, L is the actual opening of the guide vane, ; S1.4, determine whether L is satisfied a If yes, the process ends; if no, execute step S1.3 again.

[0007] It is further defined that the gradient value x=5%.

[0008] It is further defined that step S2 includes the following steps: S2.1. Obtain load instruction and obtain AGC active power distribution value P AGC ; S2.2. Get the initial active power P of the current unit int ; S2.3, through AGC active power distribution value P AGC and the current unit initial active power P int Calculate the guide vane opening feedforward value L ah : L ah = [ K q (P AGC P int ) + P int P a-1 ]+

[0009] in, K q is the feedforward coefficient, .

[0010] It is further defined that step S3 includes the following steps: S3.1. Obtain the measured water head at the current moment and measured active power ; S3.2, based on the measured water head and measured active power Determine the reference head :

[0011] in, is the set active power value of the unit, is the dead zone of active power regulation of the unit, and i is the measurement period; S3.3, based on the measured water head and reference head , determine the intermediate value of the head correction coefficient calculation :

[0012] in, Dead zone for head correction, is a fixed step size; S3.4. Calculate the intermediate value based on the head correction coefficient Determine the current head correction factor :

[0013] in, is the upper limit of the head correction coefficient, is the lower limit of the head correction coefficient; S3.5, based on the current head correction coefficient , measured water head and reference head , calculate the head correction :

[0014] in, is the upper limit of the head correction, It is the lower limit of the head correction.

[0015] It is further defined that step S4 includes the following steps: S4.1. Obtaining the reference frequency and the measured frequency at the current moment ; S4.2, according to the reference frequency and the measured frequency at the current moment Determine the frequency correction calculation amount :

[0016] in, is the adjustment rate, Correct dead zone for frequency; S4.3. Correct the calculated amount according to the frequency Determine the frequency correction amount :

[0017] in, is the upper limit of the frequency correction, It is the lower limit of the frequency correction.

[0018] It is further defined that step S5 includes the following steps: S5.1. Active power given value after head correction and frequency correction for:

[0019] S5.2, according to the active power given value And the guide vane opening-work function to get the opening given analog value :

[0020] in, .

[0021] A hydroelectric generator set active power control system, used to implement the above-mentioned hydroelectric generator set active power control method, comprising: A guide vane opening-active power function construction unit, used to construct a guide vane opening-active power function; The guide vane feedforward calculation unit is used to obtain the load instruction and obtain the guide vane opening feedforward value according to the current parameters of the hydropower unit and the guide vane opening-work power function; The water head correction calculation unit is used to determine the water head correction amount according to the current parameters and load instructions of the hydropower unit; A frequency correction calculation unit is used to determine the frequency correction amount according to the current parameters and load instructions of the hydropower unit; The guide vane opening analog value calculation unit is used to determine the guide vane opening analog value according to the load instruction, the head correction value, the frequency correction value and the guide vane opening-work function.

[0022] It is further defined that the active power control system of the hydropower unit further includes: The monitoring unit is used to receive load instructions; to determine the guide vane opening adjustment pulse instructions according to the load instructions; to provide the measured active power , reference frequency , measured frequency , measured water head and reference head ; The speed regulator configuration unit is used to adjust the guide vane opening according to the guide vane opening feedforward value, the guide vane opening analog value and / or the guide vane opening adjustment pulse instruction.

[0023] A hydroelectric generator set active power control device includes a non-volatile storage medium and a central processing unit. The non-volatile storage medium stores executable code. When the central processing unit executes the executable code, the hydroelectric generator set active power control method as described above is implemented.

[0024] The beneficial effects of the present invention are: The present invention constructs a guide vane opening-active power function through experimental data. When performing active power control on a hydropower unit, the guide vane opening feedforward value is first obtained through the current parameters of the hydropower unit and the guide vane opening-active power function, so that the guide vane opening response is adjusted to near the target value. Subsequently, the head correction amount and the frequency correction amount are calculated, and then combined with the guide vane opening-active power function, the optimized guide vane opening analog value is finally determined, and the guide vane opening is finally adjusted, thereby achieving high-speed, high-precision, and low-latency active power regulation to meet actual operational needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a step diagram of the active power control method of a hydroelectric generator set according to the present invention; Figure 2 This is a schematic diagram of the active power control system of the hydropower unit of the present invention. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] Example 1 refer to Figure 1 The present invention provides a method for controlling active power of a hydropower unit, comprising the following steps: S1. Construct guide vane opening-work function; S2. Obtain the load command, obtain the guide vane opening feedforward value based on the current parameters of the hydropower unit and the guide vane opening-work power function, and execute it; S3. Determine the water head correction amount based on the current parameters and load instructions of the hydropower unit; S4. Determine the frequency correction amount based on the current parameters and load instructions of the hydropower unit; S5. Determine the guide vane opening analog value and execute it according to the load instruction, the head correction value, the frequency correction value and the guide vane opening-work function.

[0028] To further illustrate, step S1 includes the following steps: S1.1. Under rated water head, set the guide vane opening L a=ax+L0, where x is the gradient value, a is the ath test, and L0 is the no-load opening; S1.2, according to the current guide vane opening L a , record the active power P of the hydropower unit at the corresponding moment a ; S1.3, for (L a-1 , P a-1 ) and (L a , P a ) and perform linear interpolation on the two points to obtain the guide vane opening-work function applicable to this section: P= (L L a-1 )+P a-1 Among them, L is the actual opening of the guide vane, ; S1.4, determine whether L is satisfied a If yes, the process ends; if no, execute step S1.3 again.

[0029] Specifically, under the rated head, first record the guide vane opening L0 corresponding to the no-load active power P0=0 when a=0, so set the guide vane opening L a =ax+L0, where the gradient value x can be selected as x=5%, and the gradient value can also be adjusted according to actual needs.

[0030] Then, let a = 1 and adjust the guide vane opening to obtain the active power P1 of the hydropower unit at the corresponding moment; perform linear interpolation on the two points (L0, P0) and (L1, P1) to obtain the guide vane opening-active power function applicable to this section: P = (L L0) + P0, where L is the actual opening of the guide vane, .

[0031] Then let a=2, adjust the guide vane opening, and get the active power P2 of the hydropower unit at the corresponding moment; perform linear interpolation on the two points (L1, P1) and (L2, P2) to get the guide vane opening-active power function applicable to this section: P= (L L1) + P1, where L is the actual opening of the guide vane, .

[0032] This cycle continues until L is satisfied. a The process ends when the value is 100%, and a series of guide vane opening-work function obtained by linear interpolation of two points are obtained.

[0033] Further explanation, step S2 includes the following steps: S2.1. Obtain load instruction and obtain AGC active power distribution value P AGC ; S2.2. Get the initial active power P of the current unit int ; S2.3, through AGC active power distribution value P AGC and the current unit initial active power P int Calculate the guide vane opening feedforward value L ah : L ah = [ K q (P AGC P int ) + P int P a-1 ]+

[0034] in, K q is the feedforward coefficient, .

[0035] Obtaining the guide vane opening feedforward value L ah Then, the guide vane opening feedforward value L ah The speed regulator adjusts the guide vane opening through the hydraulic system, and adjusts the guide vane opening quickly and effectively, so that the guide vane opening is adjusted to near the target opening, shortening the final adjustment time.

[0036] To further illustrate, step S3 includes the following steps: The basic idea of ​​head correction is: through the deviation between the measured head and the reference head, and the head correction coefficient , calculate the head correction , where the head correction coefficient is Can be dynamically adjusted according to head deviation.

[0037] S3.1. Obtain the measured water head at the current moment and measured active power ; S3.2, based on the measured water head and measured active power Determine the reference head :

[0038] in, is the set active power value of the unit, is the dead zone of active power regulation of the unit, and i is the measurement period.

[0039] Specifically, the measured water head is obtained by measuring the water level gauge , measured water head The measurement cycle of i=1 minute is used as an example to illustrate that the unit is in steady state by judging that the load is stable for 3 consecutive minutes. As the reference head When the unit is in the process of load adjustment or the load stable state lasts less than 3 minutes, the current reference water head is consistent with the previous reference water head. = .

[0040] S3.3, based on the measured water head and reference head , determine the intermediate value of the head correction coefficient calculation :

[0041] in, Dead zone for head correction, is a fixed step size.

[0042] Specifically, when the absolute value of the deviation between the measured head and the reference head is less than or equal to the head correction dead zone, the head fluctuation is determined to be stable, and the head correction coefficient is calculated as the intermediate value. Take it as 0.

[0043] At the current moment, the measured water head is higher than the reference water head, and the absolute value of the deviation between the two is greater than the dead zone of water head correction. In this case, the water head is judged to be too high, the unit output increases, and the guide vane opening needs to be reduced to keep the unit's actual active power stable. Therefore, the water head correction amount is negative at this time, and it is necessary to increase the fixed step size. Adjust in the negative direction.

[0044] At the current moment, the measured water head is lower than the reference water head, and the absolute value of the deviation between the two is greater than the dead zone of water head correction. In this case, it is judged that the water head is too low, the unit output is reduced, and the guide vane opening needs to be increased to keep the unit's actual active power stable. Therefore, the water head correction amount is positive at this time, and it is necessary to increase the fixed step size. Adjust in the positive direction.

[0045] S3.4. Calculate the intermediate value based on the head correction coefficient Determine the current head correction factor :

[0046] in, is the upper limit of the head correction coefficient, It is the lower limit of the head correction coefficient.

[0047] In order to avoid If the deviation from zero is too large, it will cause over-adjustment. Limiting is performed.

[0048] S3.5, based on the current head correction coefficient , measured water head and reference head , calculate the head correction :

[0049] in, is the upper limit of the head correction, The lower limit of the head correction amount, in order to avoid over-adjustment, it is necessary to correct the power component Limiting is performed.

[0050] Further explanation, step S4 includes the following steps: The basic idea of ​​frequency correction is to use the deviation between the measured frequency and the reference frequency, as well as the adjustment rate , calculate the frequency correction , by performing power-frequency correction, it can be used as an alternative to the primary frequency regulation function of the speed regulator.

[0051] S4.1. Obtaining the reference frequency and the measured frequency at the current moment ; S4.2, according to the reference frequency and the measured frequency at the current moment Determine the frequency correction calculation amount :

[0052] in, is the adjustment rate, Correction dead zone for frequency.

[0053] Specifically, when the absolute value of the deviation between the measured frequency and the reference frequency is less than or equal to the frequency correction dead zone, the frequency fluctuation is determined to be stable. Take it as 0; when the absolute value of the deviation between the measured frequency and the reference frequency is greater than the frequency correction dead zone, the frequency correction calculation amount is obtained by calculation ;in .

[0054] S4.3. Correct the calculated amount according to the frequency Determine the frequency correction amount :

[0055] in, is the upper limit of the frequency correction, It is the lower limit of the frequency correction.

[0056] Specifically, in order to avoid overshoot, the frequency correction calculation Limiting is performed to obtain the frequency correction .

[0057] To further illustrate, step S5 includes the following steps: S5.1. Active power given value after head correction and frequency correction for:

[0058] S5.2, according to the active power given value And the guide vane opening-work function to get the opening given analog value :

[0059] in, Example 2 refer to Figure 2 This embodiment provides a hydroelectric generator set active power control system, which is used to implement the hydroelectric generator set active power control method provided in Example 1, including: A guide vane opening-active power function construction unit, used to construct a guide vane opening-active power function; The guide vane feedforward calculation unit is used to obtain the load instruction, obtain the guide vane opening feedforward value according to the current parameters of the hydropower unit and the guide vane opening-work power function, and execute it; The water head correction calculation unit is used to determine the water head correction amount according to the current parameters and load instructions of the hydropower unit; A frequency correction calculation unit is used to determine the frequency correction amount according to the current parameters and load instructions of the hydropower unit; The guide vane opening analog value calculation unit is used to determine the guide vane opening analog value according to the load instruction, the head correction value, the frequency correction value and the guide vane opening-work function.

[0060] To further explain, the active power control system of the hydropower unit also includes: The monitoring unit is used to receive load instructions; to determine the guide vane opening adjustment pulse instructions according to the load instructions; to provide the measured active power , reference frequency , measured frequency , measured water head and reference head ; The speed regulator configuration unit is used to adjust the guide vane opening according to the guide vane opening feedforward value, the guide vane opening analog value and / or the guide vane opening adjustment pulse instruction.

[0061] During actual operation, the monitoring unit can be switched to the power distribution mode, and the guide vane opening feedforward value and the guide vane opening analog value are obtained by executing the active power control method of the hydropower unit. The speed regulator configuration unit is switched to the guide vane analog value control mode, and the speed regulator configuration unit is executed according to the blade opening feedforward value and the guide vane opening analog value respectively.

[0062] When the guide vane opening-active function construction unit, the guide vane feedforward calculation unit, the head correction calculation unit, the frequency correction calculation unit and / or the guide vane opening analog calculation unit fails, the monitoring unit can be switched to the power closed-loop mode, and the speed regulator configuration unit adjusts the guide vanes by switching to the guide vane pulse control mode.

[0063] Example 3 This embodiment provides an active power control device for a hydropower generator set, including a non-volatile storage medium and a central processing unit. The non-volatile storage medium stores executable code. When the central processing unit executes the executable code, the active power control method for the hydropower generator set as described in Example 1 is implemented.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the present invention.

Claims

1. A method for controlling active power of a hydropower unit, characterized in that: The following steps are involved: S1. Construct guide vane opening-work function; S2. Obtain the load command and obtain the guide vane opening feedforward value according to the current parameters of the hydropower unit and the guide vane opening-work power function; S3. Determine the water head correction amount based on the current parameters and load instructions of the hydropower unit; S4. Determine the frequency correction amount based on the current parameters and load instructions of the hydropower unit; S5. Determine the guide vane opening analog value according to the load instruction, the head correction value, the frequency correction value and the guide vane opening-work function.

2. The method for controlling active power of a hydroelectric generator set according to claim 1, characterized in that: The step S1 comprises the following steps: S1.

1. Under rated water head, set the guide vane opening L a =ax+L0, where x is the gradient value, a is the ath test, and L0 is the no-load opening; S1.2, according to the current guide vane opening L a , record the active power P of the hydropower unit at the corresponding moment a ; S1.3, for (L a-1 , P a-1 ) and (L a , P a ) and perform linear interpolation on the two points to obtain the guide vane opening-work function applicable to this section: P= (L L a-1 )+P a-1 Among them, L is the actual opening of the guide vane, ; S1.4, determine whether L is satisfied a If yes, the process ends; if no, execute step S1.3 again.

3. The active power control method of a hydroelectric generator set according to claim 2, characterized in that: The gradient value x=5%.

4. The method for controlling active power of a hydroelectric generator set according to claim 2, characterized in that: The step S2 comprises the following steps: S2.

1. Obtain load instruction and obtain AGC active power distribution value P AGC ; S2.

2. Get the initial active power P of the current unit int ; S2.3, through AGC active power distribution value P AGC and the current unit initial active power P int Calculate the guide vane opening feedforward value L ah : L ah = [ K q (P AGC P int )+ P int P a-1 ]+ in, K q is the feedforward coefficient, .

5. The method for controlling active power of a hydroelectric generator set according to claim 4, characterized in that: The step S3 comprises the following steps: S3.

1. Obtain the measured water head at the current moment and measured active power ; S3.2, based on the measured water head and measured active power Determine the reference head : in, is the set active power value of the unit, is the dead zone of active power regulation of the unit, and i is the measurement period; S3.3, based on the measured water head and reference head , determine the intermediate value of the head correction coefficient calculation : in, Dead zone for head correction, is a fixed step size; S3.

4. Calculate the intermediate value based on the head correction coefficient Determine the current head correction factor : in, is the upper limit of the head correction coefficient, is the lower limit of the head correction coefficient; S3.5, based on the current head correction coefficient , measured water head and reference head , calculate the head correction : in, is the upper limit of the head correction, It is the lower limit of the head correction.

6. The method for controlling active power of a hydroelectric generator set according to claim 5, characterized in that: The step S4 comprises the following steps: S4.

1. Obtaining the reference frequency and the measured frequency at the current moment ; S4.2, according to the reference frequency and the measured frequency at the current moment Determine the frequency correction calculation amount : in, is the adjustment rate, Correct dead zone for frequency; S4.

3. Correct the calculated amount according to the frequency Determine the frequency correction amount : in, is the upper limit of the frequency correction, It is the lower limit of the frequency correction.

7. The method for controlling active power of a hydroelectric generator set according to claim 6, characterized in that: The step S5 comprises the following steps: S5.

1. Active power given value after head correction and frequency correction for: S5.2, according to the active power given value And the guide vane opening-work function to get the opening given analog value : in, .

8. A hydroelectric generator active power control system, characterized in that: A method for controlling the active power of a hydroelectric generator set according to any one of claims 1 to 7, comprising: A guide vane opening-active power function construction unit, used to construct a guide vane opening-active power function; The guide vane feedforward calculation unit is used to obtain the load instruction and obtain the guide vane opening feedforward value according to the current parameters of the hydropower unit and the guide vane opening-work power function; The water head correction calculation unit is used to determine the water head correction amount according to the current parameters and load instructions of the hydropower unit; A frequency correction calculation unit is used to determine the frequency correction amount according to the current parameters and load instructions of the hydropower unit; The guide vane opening analog value calculation unit is used to determine the guide vane opening analog value according to the load instruction, the head correction value, the frequency correction value and the guide vane opening-work function.

9. The active power control system of a hydroelectric generator set according to claim 8, characterized in that: The active power control system of the hydropower unit also includes: The monitoring unit is used to receive load instructions; to determine the guide vane opening adjustment pulse instructions according to the load instructions; to provide the measured active power , reference frequency , measured frequency , measured water head and reference head ; The speed regulator configuration unit is used to adjust the guide vane opening according to the guide vane opening feedforward value, the guide vane opening analog value and / or the guide vane opening adjustment pulse instruction.

10. A hydropower unit active power control device, characterized in that: The invention comprises a non-volatile storage medium and a central processing unit, wherein the non-volatile storage medium stores executable code, and when the central processing unit executes the executable code, the active power control method of the hydropower unit according to any one of claims 1 to 7 is implemented.

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