Experimental turbine governor with wide speed range regulation function and method

Abstract

A kind of test water turbine governor with wide speed range regulating function and method, it includes the PID module of frequency setting module electric connection of the present application and frequency measurement module, guide vane given module and PID module electric connection, guide vane given module and guide vane measurement module are electrically connected with guide vane control module, guide vane control module is electrically connected with electro-hydraulic conversion module, guide vane module and unit speed module in proper order subsequently;Unit speed module is electrically connected with frequency measurement module;By setting frequency difference threshold module before PID module, PID module is also connected with PID parameter module and water hammer limiting module, guide vane given module is connected with opening limiting module, so as to realize the speed accurate regulation of unit under different speed regulation, simultaneously verify the operating condition of unit in low speed interval, obtain accurate test parameter, and governor has automatic regulating function under low frequency or high frequency condition.

Description

Technical Field

[0001] This invention belongs to the technical field of hydropower station turbine governors, and relates to a test turbine governor with wide speed range regulation function and method. Background Technology

[0002] The turbine governor is the core control device of the hydro-generator, and its main function is to achieve closed-loop regulation of the unit's speed. Generally, the governor's speed control target is 50Hz or the grid frequency signal. Before the hydro-generator unit is dismantled during a major overhaul, according to regulations, it is necessary to complete operating condition tests of the unit at different speeds to provide important data support for subsequent verification of the unit's maintenance quality. Currently, the operation method involves power plant operators manually opening the guide vanes from the on-site control panel. Once the unit speed rises to the corresponding speed point, the guide vanes are kept under manual control. At this time, the unit speed is purely open-loop regulated. This method has the following shortcomings: 1. The unit's frequency regulation range is small, lacking low-speed and high-speed regulation functions; 2. The unit speed is regulated in an open-loop manner, resulting in unstable and inaccurate speed regulation; 3. When the speed deviates from the target value, the guide vane frequency needs to be manually adjusted to stabilize it, resulting in high labor costs.

[0003] In existing solutions, the speed governor has an automatic speed adjustment function, but the target adjustment value is 50Hz or the grid frequency, and the frequency is set with adjustment limits, generally 45Hz-55Hz. Low speed control can only be achieved by manually operating the guide vanes.

[0004] The unit's speed regulation range is limited, and automatic frequency control cannot be achieved beyond a certain speed range. Current frequency regulation only tracks the grid frequency or 50Hz, and the frequency regulation range is only set to 48-52Hz under no-load disturbance conditions. PID control strategies are lacking for speed ranges other than the set speed regulation range. Water hammer suppression functionality is also absent. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a turbine governor and method with wide speed range adjustment function for testing, so as to accurately adjust the speed of the turbine generator unit under different speed adjustment before the overhaul of the turbine generator unit, and at the same time verify the operating conditions of the unit in the low speed range and obtain accurate test parameters.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a turbine governor with wide speed range adjustment function for testing, comprising a PID module electrically connected to a frequency setting module and a frequency measurement module, a guide vane setting module electrically connected to the PID module, a guide vane setting module and a guide vane measurement module electrically connected to a guide vane control module, and an electro-hydraulic conversion module, a guide vane module and a unit speed module electrically connected in sequence after the guide vane control module; the unit speed module is electrically connected to the frequency measurement module; before the overhaul of the turbine generator unit, the speed of the unit is precisely adjusted under different speed regulation conditions, and the operating conditions of the unit in the low speed range are verified to obtain accurate test parameters.

[0007] The frequency setting module is also electrically connected to the frequency setting limit module.

[0008] Set the frequency difference threshold module before the PID module.

[0009] The PID module is also electrically connected to the PID parameter module and the water hammer limiting module.

[0010] The guide vane setting module is also electrically connected to the opening limit module.

[0011] The speed regulation method of the turbine governor with wide speed range regulation function used in the experiment, as described above, includes the following steps:

[0012] S1, the frequency measurement module acquires the unit frequency signal F and completes the per-unit f0;

[0013] S2, the frequency setting module meets the wide speed range adaptive adjustment range of 0-100Hz for the hydro-generator set; if 10-75Hz is selected, no calculation will be performed if the set value exceeds this threshold range; after the set value SF is input, it is consistent with the frequency measurement and is standardized to the same unit sf0; the frequency setting and frequency setting limit data source are taken from the governor cabinet touch screen or the power station monitoring system.

[0014] S3, the frequency difference threshold module calculates the frequency difference = frequency setting - frequency feedback, Δf = sf0 - f0; when the frequency difference exceeds the frequency threshold, PID calculation starts, and the threshold is manually modified.

[0015] S4, the PID module calculates the guide vane setpoint based on the frequency difference, Ypid=Yp+Yi+Yd; where the governor PID parameters Kp, Ki, and Kd are selected as the optimal control parameters based on the current unit head and opening degree;

[0016] S5, the water hammer limiting module changes the rate of change of the guide vane PID, reducing the water hammer effect formed in the water intake pipe at the moment of guide vane action;

[0017] S6, the guide vane measurement module measures the guide vane opening of the turbine servo unit. The change in guide vane opening is expressed in unit Y, and its dimension is consistent with Ypid.

[0018] S7, the opening limit module constrains the guide vane's range of motion, serving as a backup protection function, Limit{10%≤Ypid≤75%};

[0019] S8, the difference between the guide vane setpoint module and the guide vane measurement module is ΔY=Ypid-Y. When the guide vane deviation ΔY exceeds the threshold, the guide vane adjustment is started. After the deviation value is calibrated, it is converted into the control current output to the electro-hydraulic conversion device through the guide vane control module; a current of 4~20mA is used to drive the proportional valve.

[0020] S9 achieves precise frequency regulation of the turbine generator set Y→F by changing the guide vanes.

[0021] The adjustment deviation protection is implemented so that when the frequency exceeds the set frequency range x, the guide vanes remain in a shutdown strategy. x can be set manually, typically ±0.5Hz. After the speed is stabilized, if the deviation between the guide vane setting and feedback exceeds the positive value of the range g, there are two scenarios: First, when the deviation between the guide vane setting and feedback is greater than g, the speed controller reports a guide vane adjustment fault, and the guide vanes are manually controlled, remaining stationary. Second, when the deviation between the guide vane setting and feedback is less than -g, the speed controller reports a guide vane adjustment fault, and the guide vanes are fully closed to prevent the unit from running out of speed. The value of g is set manually, typically 1%. The deviation protection is not activated during startup.

[0022] In manual mode, the guide vanes are adjusted to the target speed. After the unit frequency stabilizes, the automatic frequency adjustment is enabled. In automatic mode, a slow start-up strategy is adopted, and the guide vane setting is increased or decreased in a certain step. The guide vane changes are stable and smooth, avoiding the unit frequency from exceeding the adjustment range. After the unit frequency stabilizes, the automatic frequency adjustment is enabled.

[0023] The main beneficial effects of this invention are as follows:

[0024] Before the overhaul of the hydro-generator unit, the unit's speed is precisely adjusted under different speed regulation conditions, and the operating conditions of the unit in the low speed range are verified to obtain accurate test parameters.

[0025] The speed controller has an automatic adjustment function under low or high frequency conditions.

[0026] For testing purposes, the speed controller's corresponding functions are deactivated during non-testing periods, and can be activated or deactivated as needed before testing. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] Figure 2 This is a schematic diagram of the existing technology.

[0030] In the diagram: Frequency setting module 1; Frequency setting limit module 11; Frequency measurement module 2; PID module 3; Frequency difference threshold module 31; PID parameter module 32; Water hammer limit module 33; Guide vane setpoint module 4; Opening limit module 41; Guide vane measurement module 5; Guide vane control module 6; Electro-hydraulic conversion module 7; Guide vane module 8; Unit speed module 9. Detailed Implementation

[0031] like Figures 1-2 In this study, a test turbine governor with wide-range speed regulation function was developed.

[0032] Example 1,

[0033] like Figure 1 The system includes a PID module 3 electrically connected to a frequency setting module 1 and a frequency measurement module 2; a guide vane setting module 4 electrically connected to the PID module 3; a guide vane setting module 4 and a guide vane measurement module 5 electrically connected to a guide vane control module 6; and an electro-hydraulic conversion module 7, a guide vane module 8, and a unit speed module 9 electrically connected in sequence after the guide vane control module 6; the unit speed module 9 is electrically connected to the frequency measurement module 2.

[0034] Example 2,

[0035] like Figure 1 middle,

[0036] The frequency setting module 1 is also electrically connected to the frequency setting limit module 11.

[0037] PID module 3 is preceded by frequency difference threshold module 31.

[0038] The PID module 3 is also electrically connected to the PID parameter module 32 and the water hammer limiting module 33.

[0039] The guide vane setting module 4 is also electrically connected to the opening limit module 41.

[0040] Example 3,

[0041] like Figure 1 The speed regulation method of the turbine governor with wide speed range regulation function used in the experiment, as described above, includes the following steps:

[0042] S1, Frequency measurement module 2 acquires the unit frequency signal F and completes the per-unit f0;

[0043] S2, the frequency setting module 1 meets the wide speed range adaptive adjustment range of 0-100Hz for the hydro-generator set; if 10-75Hz is selected, no calculation will be performed if the set value exceeds this threshold range; after the set value SF is input, it is consistent with the frequency measurement and is standardized to the same unit sf0; the frequency setting and frequency setting limit data source are taken from the governor cabinet touch screen or the power station monitoring system.

[0044] S3, the frequency difference threshold module 31 calculates the frequency difference = frequency setting - frequency feedback, Δf = sf0 - f0; when the frequency difference exceeds the frequency threshold, PID calculation starts and the threshold is manually modified.

[0045] S4, PID module 3 calculates the guide vane setpoint based on the frequency difference, Ypid=Yp+Yi+Yd; where the governor PID parameters Kp, Ki, and Kd are selected as the optimal control parameters based on the current unit head and opening degree;

[0046] S5, the water hammer limiting module 33 changes the rate of change of the guide vane PID to reduce the water hammer effect formed in the water pipe during the moment of guide vane action.

[0047] S6, Guide vane measurement module 5 measures the opening of the guide vane of the turbine servo unit. The per unit of the guide vane opening change is Y, and the dimension is consistent with Ypid.

[0048] S7, the opening limit module 41 constrains the operating range of the guide vane, serving as a backup protection function, Limit{10%≤Ypid≤75%};

[0049] S8, the difference between guide vane setting module 4 and guide vane measurement module 5 is △Y=Ypid-Y. When the guide vane deviation △Y exceeds the threshold, the guide vane adjustment is started. After the deviation value is calibrated, it is converted into the control current output to the electro-hydraulic conversion device through the guide vane control module 6; a current of 4~20mA is taken to drive the proportional valve.

[0050] S9 achieves precise frequency regulation of the turbine generator set Y→F by changing the guide vanes.

[0051] Before a major overhaul of the hydro-generator unit, precise speed adjustment is performed at different speeds to verify the unit's operating conditions in the low-speed range and obtain accurate test parameters. The governor has an automatic adjustment function under low-frequency or high-frequency conditions. Used for testing, the corresponding function of the governor is deactivated during non-testing periods; it can be activated or deactivated as needed before testing.

[0052] Example 4,

[0053] like Figure 1In the process of adjusting the deviation protection, when the frequency exceeds the set frequency range x, the guide vanes remain in the shutdown strategy. x can be set manually, generally ±0.5Hz. After the speed is stabilized, when the deviation between the guide vane setpoint and feedback exceeds the positive value of the range g, there are two situations: First, when the deviation between the guide vane setpoint and feedback is greater than g, the speed controller reports a blade adjustment fault, the guide vanes are manually controlled, and the guide vanes remain stationary; Second, when the deviation between the guide vane setpoint and feedback is less than -g, the speed controller reports a blade adjustment fault, the guide vanes are fully closed to prevent the unit from running away with the speed. The value of g is set manually, taking 1%. The deviation protection is not activated during startup.

[0054] like Figure 1 In the manual mode, the guide vanes are adjusted to the target speed. After the unit frequency stabilizes, the automatic frequency adjustment is enabled. In the automatic mode, a slow start-up strategy is adopted. The guide vane setting is increased or decreased in a certain step size. The guide vane changes are stable and smooth, avoiding the unit frequency from exceeding the adjustment range. After the unit frequency stabilizes, the automatic frequency adjustment is enabled.

[0055] like Figure 2 In existing technologies, speed governors have automatic speed adjustment functions, but the target adjustment value is 50Hz or the grid frequency, and the frequency is set with adjustment limits, typically 45Hz-55Hz. Low-speed control can only be achieved by manually operating the guide vanes. In this application, a frequency setting limit module 11 is set after the frequency setting module 1; a frequency difference threshold module 31 is set before the PID module 3; the PID module 3 is also connected to the PID parameter module 32 and the water hammer limit module 33; the guide vane setting module 4 is connected to the opening limit module 41; thereby enabling precise speed adjustment of the unit under different speed settings, while verifying the unit's operating conditions in the low-speed range and obtaining accurate test parameters.

[0056] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A speed regulation method for a turbine governor with wide speed range regulation function for experimental use, characterized in that: The water turbine governor comprises a frequency setting module (1), a PID module (3) electrically connected with the frequency setting module (1) and a frequency measurement module (2), a guide vane setting module (4) electrically connected with the PID module (3), a guide vane measurement module (5) and the guide vane setting module (4) electrically connected with a guide vane control module (6), and the guide vane control module (6) electrically connected with an electro-hydraulic conversion module (7), a guide vane module (8) and a unit speed module (9) in sequence; the unit speed module (9) is electrically connected with the frequency measurement module (2); before overhauling the hydro-generator unit, the speed of the unit is accurately adjusted under different speed adjustments, and meanwhile, the operation condition of the unit in a low speed range is verified, so that accurate test parameters are obtained; The speed regulating method comprises the following steps: S1, the frequency measurement module (2) collects a unit frequency signal F and completes a unit f0; S2, the frequency setting module (1) satisfies a wide speed range self-adaptive regulating range of 0-100 Hz of the hydro-generator unit; 10-75 Hz is selected, a set value exceeds the threshold interval, and no operation is performed; after the set value SF is input, the frequency measurement is consistent, and the same dimension unit sf0 is performed; the frequency setting and the frequency setting limit data source are obtained from a governor electric cabinet touch screen or a power station monitoring system; S3, a frequency difference threshold module (31) calculates a frequency difference = frequency setting-frequency feedback, and △f=sf0-f0; when the frequency difference exceeds a frequency threshold, PID calculation is started, and the threshold is manually modified; S4, the PID module (3) calculates a guide vane set value Ypid=Yp+Yi+Yd according to the frequency difference; wherein PID parameters Yp, Yi and Yd of the governor are selected as optimal control parameters according to a current unit water head and opening; S5, a water hammer limiting module (33) changes a change rate of the guide vane PID, and reduces a water hammer effect formed by a water conduit at a guide vane action moment; S6, a guide vane measurement module (5) measures a guide vane opening of a water turbine servomotor, a guide vane opening change unit is Y, and the dimension is consistent with Ypid; S7, an opening limiting module (41) restricts a guide vane action range, and plays a backup protection role, and Limit{10%≤Ypid≤75%}; S8, a difference △Y=Ypid-Y between the guide vane setting module (4) and the guide vane measurement module (5) is calculated; when the guide vane deviation △Y exceeds a threshold, guide vane adjustment is started, the deviation unit is converted into a control current output to an electro-hydraulic conversion device through the guide vane control module (6); and a 4-20 mA current drives a proportional valve; S9, frequency accurate regulation Y→F of the hydro-generator unit is realized through guide vane change.

2. The method of claim 1, wherein the method is characterized by: The frequency setting module (1) is further electrically connected with a frequency setting limiting module (11).

3. The method of claim 1, wherein the method is characterized by: The PID module (3) is provided with the frequency difference threshold module (31) in front.

4. The method of claim 1, wherein the method is characterized by: The PID module (3) is further electrically connected with a PID parameter module (32) and the water hammer limiting module (33).

5. The method of claim 1, wherein the method is characterized by: The guide vane setting module (4) is further electrically connected with the opening limiting module (41).

6. The method of claim 1, wherein the method is characterized by: Adjusting deviation protection, when the frequency exceeds the set frequency interval x, the guide vane remains the shutdown strategy, x is artificially set, taking ± 0.5 Hz; after the speed stabilizing adjustment, the guide vane given and feedback deviation exceeds the interval g positive value; including two cases: one is the guide vane set and feedback deviation is greater than g, the governor reports the guide vane adjustment fault, the guide vane is manually controlled, and the guide vane remains unchanged; two is the guide vane set and feedback deviation is less than -g, the governor reports the guide vane adjustment fault, the guide vane is fully closed, to prevent the unit from appearing speed runaway; g value is artificially set, taking 1%; deviation protection is not put into operation during startup.

7. The speed regulation method of the turbine governor with wide speed range regulation function for experimental use according to claim 1, characterized in that: The electric manual mode adjusts the guide vane to the target speed, and after the unit frequency stabilizes, the frequency automatic adjustment is enabled; the automatic mode adopts slow startup strategy, the guide vane given is increased or decreased by a certain step, the guide vane changes stably and smoothly, avoiding the unit frequency exceeding the adjustment range; after the unit frequency stabilizes, the frequency self-adjustment enable is enabled.

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