Variable speed unit control method based on dynamic target opening and dynamic target rotating speed

Abstract

The application discloses a variable-speed unit control method based on dynamic target opening and dynamic target rotating speed, which comprises the following steps: obtaining real-time operation parameters and unit parameters; forming an electromagnetic power control amount by a converter; calculating a target power correction value; calculating an input power reference value; calculating a guide vane opening basic control amount and a water turbine rotating speed basic control amount; calculating a guide vane opening control value and a rotating speed control value; calculating a mechanical hydraulic system control amount and inputting the mechanical hydraulic system control amount into the mechanical hydraulic system to obtain a dynamic opening / rotating speed control amount; and completing real-time control of the target variable-speed unit according to the electromagnetic power control amount and the dynamic opening / rotating speed control amount. In the adjusting process, the dynamic target opening and the dynamic target rotating speed are simultaneously used for unit output adjusting, the rotating speed error and the opening error in the load adjusting process are reduced, the operation efficiency is improved, the water hammer effect is reduced, the stability is improved, and the method has high reliability, good stability and high efficiency.

Description

Technical Field

[0001] This invention belongs to the field of turbine control, specifically relating to a variable speed turbine control method based on dynamic target opening degree and dynamic target speed. Background Technology

[0002] With the development of power systems, the load on these systems is increasing. Hydropower systems, with their advantages of low generation costs and high efficiency, occupy an important position in my country's power system. Pumped storage power stations are an important form of hydropower station; they not only possess the advantages of hydropower systems but also offer the advantage of rapid load response. Therefore, in the power system, pumped storage power stations primarily undertake peak shaving and frequency regulation tasks; through peak shaving and frequency regulation, pumped storage power stations effectively ensure the safe operation of the power grid. Therefore, the control of pumped storage power station units is particularly important.

[0003] Currently, pumped storage power stations all use traditional hydroelectric generators or constant-speed pumped storage units. Due to inherent design limitations, these units suffer from difficulties operating under low loads and low efficiency at low loads. Therefore, these traditional units are gradually becoming unsuitable for today's power systems.

[0004] Variable speed turbine generators are one of the best choices for future pumped storage power stations, offering advantages such as a wide operating range, large power adjustment range, and extremely high efficiency during steady-state operation. Therefore, the control of variable speed turbine generators is of paramount importance. However, applying traditional control methods to variable speed turbine generators results in slow response and severe mechanical wear. Furthermore, current research in my country on the control of variable speed turbine generators is lacking. Summary of the Invention

[0005] The purpose of this invention is to provide a variable speed generator control method based on dynamic target opening degree and dynamic target speed, which is highly reliable, stable and efficient.

[0006] The variable speed generator control method based on dynamic target opening degree and dynamic target speed provided by this invention includes the following steps:

[0007] S1. Obtain the real-time operating parameters and unit parameters of the target variable speed unit;

[0008] S2. The converter of the target variable speed unit generates an electromagnetic power control quantity based on the previous active power setpoint of the turbine;

[0009] S3. Calculate the target power correction value based on the parameter information obtained in step S1;

[0010] S4. Calculate the input power reference value based on the target power correction value obtained in step S3;

[0011] S5. Based on the input power reference value obtained in step S4, and combined with the comprehensive characteristic curve of the turbine of the target variable speed unit, calculate the basic control quantity of guide vane opening and the basic control quantity of turbine speed.

[0012] S6. Based on the basic control quantity of guide vane opening obtained in step S5, calculate the guide vane opening control value; based on the basic control quantity of turbine speed obtained in step S5, calculate the turbine speed control value.

[0013] S7. Based on the guide vane opening control value and speed control value obtained in step S6, calculate the control quantity of the mechanical hydraulic system of the target variable speed unit, and input it into the mechanical hydraulic system to obtain the dynamic opening / speed control quantity.

[0014] S8. Based on the electromagnetic power control quantity obtained in step S2 and the dynamic opening / speed control quantity obtained in step S7, complete the real-time control of the target variable speed unit.

[0015] Step S3 involves calculating the target power correction value based on the parameter information obtained in step S1. Specifically, based on the parameter information obtained in step S1, the target power correction value ΔP is calculated as ΔP = PP. m0 P is the target power value for this test. m0 This is the previous power target value.

[0016] Step S4, which involves calculating the input power reference value based on the target power correction value obtained in step S3, specifically includes the following steps:

[0017] The input power reference value P is calculated using the following formula. mrefp :

[0018] P mrefp =P m0 -k p Δx+ΔP

[0019] In the formula P m0 The previous power target value; k p Δx is the conversion coefficient from speed deviation to power; Δx is the speed control value; ΔP is the target power correction value.

[0020] Step S5, which involves calculating the basic control values ​​for guide vane opening and turbine speed based on the input power reference value obtained in step S4 and the comprehensive characteristic curve of the target variable speed unit's turbine, specifically includes the following steps:

[0021] Based on the input power reference value P obtained in step S4 mrefpThe formula for calculating the current operating head H and turbine power of the target variable speed turbine unit. The intermediate variable Q was calculated. 11 η; and then combine the comprehensive characteristic curve of the turbine of the target variable speed unit. The basic control values ​​for guide vane opening y* and turbine speed n* are calculated; where P m Where γ is the turbine power, γ is the specific gravity of water, D1 is the turbine runner diameter, and Q is the turbine power output. 11 Let η be the unit flow rate of the turbine, η be the turbine efficiency, a be the turbine guide vane opening, and n be the turbine guide vane opening. 11 This represents the unit rotational speed of the water turbine.

[0022] Step S6, which involves calculating the guide vane opening control value based on the basic control quantity of the guide vane opening obtained in step S5, and calculating the turbine speed control value based on the basic control quantity of the turbine speed obtained in step S5, specifically includes the following steps:

[0023] Based on the basic control value y* of the guide vane opening obtained in step S5, the guide vane opening control value Δy is calculated as follows: Among them, a max y represents the maximum guide vane opening of the turbine, and y represents the current guide vane opening of the turbine unit.

[0024] Based on the turbine speed basic control quantity n* obtained in step S5, the speed control value Δx is calculated as follows: Where H is the current operating head H of the target variable speed unit, D1 is the turbine runner diameter, and n r denoted as the rated speed of the unit, and x is the per-unit value of the measured speed of the unit.

[0025] Step S7 involves calculating the control quantity of the mechanical-hydraulic system of the target variable speed unit based on the guide vane opening control value and speed control value obtained in step S6. Specifically, based on the guide vane opening control value Δy and speed control value Δx obtained in step S6, a PID control algorithm is used to calculate the guide vane opening control value Δy and speed control value Δx respectively, and the calculation results are added together to obtain the control quantity of the mechanical-hydraulic system of the target variable speed unit.

[0026] The variable speed turbine control method based on dynamic target opening degree and dynamic target speed provided by this invention simultaneously uses dynamic target opening degree and dynamic target speed to regulate the turbine output during the adjustment process. This reduces the speed error and opening degree error during load adjustment, allowing the turbine to maintain near the optimal efficiency point at different opening degrees during dynamic adjustment. This improves the turbine operating efficiency during dynamic response, reduces the water hammer effect during dynamic adjustment of turbine output, and improves the stability of the hydropower unit during dynamic adjustment. Moreover, this invention has high reliability, good stability, and high efficiency. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the method flow of the present invention.

[0028] Figure 2 This is a schematic diagram illustrating the concept of the method of the present invention.

[0029] Figure 3 This is a schematic diagram of the change curves between the target speed and the measured speed during a significant load increase in the method of the present invention.

[0030] Figure 4 This is a schematic diagram of the change curves of the target opening degree and the measured opening degree during the process of significantly increasing the load in the method of the present invention.

[0031] Figure 5 This is a schematic diagram showing the high-efficiency operation variation curves of the method of the present invention and existing methods without considering the load adjustment process. Detailed Implementation

[0032] like Figure 1 The diagram shown is a schematic representation of the method flow of the present invention: The variable speed generator control method based on dynamic target opening degree and dynamic target speed provided by the present invention includes the following steps:

[0033] S1. Obtain the real-time operating parameters and unit parameters of the target variable speed unit;

[0034] S2. The converter of the target variable speed unit generates an electromagnetic power control quantity based on the previous active power setpoint of the turbine;

[0035] S3. Based on the parameter information obtained in step S1, calculate the target power correction value; specifically, based on the parameter information obtained in step S1, calculate the target power correction value ΔP as ΔP = PP. m0 P is the target power value for this test. m0 This is the previous power target value;

[0036] S4. Calculate the input power reference value based on the target power correction value obtained in step S3; specifically, this includes the following steps:

[0037] The input power reference value P is calculated using the following formula. mrefp :

[0038] P mrefp =P m0 -k p Δx+ΔP

[0039] In the formula P m0 The previous power target value; k pΔx is the conversion coefficient from speed deviation to power; ΔP is the speed control value; ΔP is the target power correction value.

[0040] S5. Based on the input power reference value obtained in step S4, and combined with the comprehensive characteristic curve of the turbine of the target variable speed unit, calculate the basic control values ​​for the guide vane opening and the turbine speed; specifically including the following steps:

[0041] Based on the input power reference value P obtained in step S4 mrefp The formula for calculating the current operating head H and turbine power of the target variable speed turbine unit. The intermediate variable Q was calculated. 11 η; and then combine the comprehensive characteristic curve of the turbine of the target variable speed unit. The basic control values ​​for guide vane opening y* and turbine speed n* are calculated; where P m Where γ is the turbine power, γ is the specific gravity of water, D1 is the turbine runner diameter, and Q is the turbine power output. 11 Let η be the unit flow rate of the turbine, η be the turbine efficiency, a be the turbine guide vane opening, and n be the turbine guide vane opening. 11 The unit speed of the water turbine;

[0042] S6. Based on the basic control quantity of guide vane opening obtained in step S5, calculate the guide vane opening control value; based on the basic control quantity of turbine speed obtained in step S5, calculate the turbine speed control value; specifically including the following steps:

[0043] Based on the basic control value y* of the guide vane opening obtained in step S5, the guide vane opening control value Δy is calculated as follows: Among them, a max y represents the maximum guide vane opening of the turbine, and y represents the current guide vane opening of the turbine unit.

[0044] Based on the turbine speed basic control quantity n* obtained in step S5, the speed control value Δx is calculated as follows: Where H is the current operating head H of the target variable speed unit, D1 is the turbine runner diameter, and n r The rated speed of the unit is given by , and x is the per-unit value of the measured speed of the unit.

[0045] S7. Based on the guide vane opening control value and speed control value obtained in step S6, calculate the control quantity of the mechanical-hydraulic system of the target variable speed unit, and input it into the mechanical-hydraulic system to obtain the dynamic opening / speed control quantity; specifically, based on the guide vane opening control value Δy and speed control value Δx obtained in step S6, use the PID control algorithm to calculate the guide vane opening control value Δy and speed control value Δx respectively, and add the calculation results to obtain the control quantity of the mechanical-hydraulic system of the target variable speed unit, and then input it into the mechanical-hydraulic system to obtain the dynamic opening / speed control quantity;

[0046] S8. Based on the electromagnetic power control quantity obtained in step S2 and the dynamic opening / speed control quantity obtained in step S7, complete the real-time control of the target variable speed unit.

[0047] This invention enables dynamic changes in target rotational speed and target guide vane opening, allowing the actual turbine rotational speed and guide vane opening to quickly track the dynamic target rotational speed and target opening curves. This method not only achieves high-efficiency turbine operation at stable operating points but also ensures turbine operation within its high-efficiency range during significant load adjustments, while substantially reducing water hammer during load regulation. This type of load regulation is particularly suitable for pumped-pumped air storage systems during significant load adjustments. Figure 2 The general idea of ​​the method of this invention is given. Figures 3-4 The curves showing the changes in target speed and measured speed, target opening degree and measured opening degree during a significant load increase are presented. Figure 5 Strategy 2 is the method of this invention, while Strategy 1 is conventional variable speed control, which does not consider high-efficiency operation during load adjustment. Figures 3-5 As can be seen, the method of the present invention has a good control effect.

[0048] The variable speed turbine control method based on dynamic target opening degree and dynamic target speed provided by this invention has a rapid electromagnetic power response under load regulation, and can complete electromagnetic power regulation within milliseconds. The turbine operates at its highest efficiency line under both the initial and final power regulation conditions, exhibiting high steady-state operating efficiency and good unit stability. Simultaneous adjustment of turbine output using both speed and opening degree during power regulation provides the advantage of fast turbine output regulation on the prime mover side. This invention fully utilizes the optimal efficiency tracking unit, enabling the turbine load to be less than 40% of the unit's rated load, achieving rapid and significant load increases under low load conditions. The control strategy of this invention simultaneously uses speed error and opening degree error, maintaining safe and stable unit operation even when the opening degree signal disappears, demonstrating high fault tolerance in the power control strategy.

Claims

1. A control method for a variable speed generator unit based on dynamic target opening degree and dynamic target speed, comprising the following steps: S1. Obtain the real-time operating parameters and unit parameters of the target variable speed unit; S2. The converter of the target variable speed unit generates an electromagnetic power control quantity based on the previous active power setpoint of the turbine; S3. Calculate the target power correction value based on the parameter information obtained in step S1; specifically, calculate the target power correction value based on the parameter information obtained in step S1. for , This is the target power value for this project. This is the previous power target value; S4. Based on the target power correction value obtained in step S3, calculate the input power reference value; specifically including the following steps: The input power reference value is calculated using the following formula. : In the formula This is the previous power target value; This is the conversion coefficient from speed deviation to power. This is the speed control value; This is the target power correction value; S5. Based on the input power reference value obtained in step S4, and combined with the comprehensive characteristic curve of the turbine of the target variable speed unit, calculate the basic control values ​​for the guide vane opening and the turbine speed; specifically including the following steps: Based on the input power reference value obtained in step S4 Current operating head of the target variable speed unit Formula for calculating the turbine power of the target variable speed unit The intermediate variables were calculated. Furthermore, combining this with the comprehensive characteristic curve of the turbine of the target variable speed unit. The basic control value of guide vane opening is calculated. Basic control quantity of turbine speed ;in, For the power of the water turbine, The density of water, The diameter of the turbine runner. The unit flow rate of the water turbine, For the efficiency of the water turbine, For the turbine guide vane opening, The unit speed of the water turbine; S6. Based on the basic control quantity of guide vane opening obtained in step S5, calculate the guide vane opening control value; based on the basic control quantity of turbine speed obtained in step S5, calculate the turbine speed control value; specifically including the following steps: Based on the guide vane opening basic control value obtained in step S5 The guide vane opening control value was calculated. for ;in, This represents the maximum guide vane opening of the water turbine. This represents the current guide vane opening value of the turbine unit; Based on the basic control quantity of turbine speed obtained in step S5 The speed control value is calculated. for ;in, The current operating head of the target variable speed unit , The diameter of the turbine runner. The rated speed of the unit, This is the per-unit value of the measured unit speed; S7. Based on the guide vane opening control value and speed control value obtained in step S6, calculate the control quantity of the mechanical hydraulic system of the target variable speed unit, and input it into the mechanical hydraulic system to obtain the dynamic opening / speed control quantity; S8. Based on the electromagnetic power control quantity obtained in step S2 and the dynamic opening / speed control quantity obtained in step S7, complete the real-time control of the target variable speed unit.

2. The variable speed unit control method based on dynamic target opening degree and dynamic target speed according to claim 1, characterized in that... Step S7 involves calculating the control quantity of the mechanical-hydraulic system of the target variable speed unit based on the guide vane opening control value and speed control value obtained in step S6. Specifically, this involves calculating the control quantity based on the guide vane opening control value obtained in step S6. and speed control value The PID control algorithm is used to control the guide vane opening value. and speed control value The calculations are performed and the results are added together to obtain the control quantity of the mechanical-hydraulic system of the target variable speed unit.

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