Stable control method for power regulation of two-stage series impulse power station with regulating pool

Abstract

The application discloses a stable control method for power regulation of a two-stage series-connected impulse power station with a regulating pool, which firstly establishes a mathematical model of the series-connected impulse power station with the regulating pool, and proposes a power-water level coordinated control strategy, namely, a proportional integral control strategy with a relative value of a power deviation of a first-stage power station as an input signal for the first-stage power station, and a double proportional integral control strategy with a relative value of a power deviation of a second-stage power station and a relative value of a water level deviation of the regulating pool as input signals for the second-stage power station; on the basis, a stability analysis model of the series-connected power station is constructed, and a determination method for the governor control parameters of the first-stage power station and the second-stage power station is proposed. The control method proposed by the application not only can realize the rapid and stable regulation of the power of the series-connected power station, but also can effectively guarantee the fluctuation stability of the water level of the regulating pool, has the advantages of clear physical meaning and strong engineering applicability, provides a theoretical basis for guaranteeing the synchronous stable operation of the series-connected impulse power station with the regulating pool, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering, specifically to a stable control method for power regulation of a two-stage series impulse power station with a regulating pool. Background Technology

[0002] Against the backdrop of energy structure transformation, accelerating hydropower development has become a key measure to promote the development of clean energy. Cascade hydropower stations are an important form of hydropower resource development. In high mountain and canyon areas, although hydropower resources are extremely abundant and highly concentrated, complex geological conditions and limited engineering layout constraints often limit the construction of power stations to reservoirs with relatively small capacities, i.e., regulating ponds. Series impulse hydropower stations with regulating ponds, due to their ability to adapt to complex geological conditions and fully utilize water head, are gradually becoming a promising layout form.

[0003] Unlike conventional single-stage hydropower stations, series-connected impulse hydropower stations with regulating pools are interconnected by regulating pools of limited volume, resulting in close hydraulic integration between the stations and making decoupled operation difficult. During normal operation, the upstream and downstream stations must maintain equal flow rates to avoid significant fluctuations in the regulating pool water level caused by flow mismatch, which could affect the safety and stability of the entire series-connected hydropower system. Therefore, ensuring flow matching between stations while achieving power regulation within the station itself becomes a key issue affecting the stable operation of series-connected hydropower stations. While research on the operational stability of conventional single-stage hydropower stations is relatively mature, in-depth research on the stable control methods for the coordinated operation of series-connected impulse hydropower stations with regulating pools is still lacking.

[0004] Therefore, there is an urgent need to invent a stable control method for two-stage series impulse power regulation of a power plant with a regulating pool, so as to provide a basis for the safe and stable operation of a series power plant system. Summary of the Invention

[0005] Purpose of the invention: To overcome the shortcomings of the existing technology, the purpose of this invention is to provide a stable control method for power regulation of a two-stage series impulse power plant with a regulating pool. This method can not only achieve rapid and stable regulation of the power plant's power, but also effectively suppress water level deviation in the regulating pool and stabilize it. It has the advantages of clear physical meaning and strong engineering applicability.

[0006] Technical solution: To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] The present invention provides a stable control method for power regulation of a two-stage series-connected impulse power plant with a regulating pool, comprising the following steps:

[0008] Step 1: Establish a mathematical model of a two-stage series impulse power plant system with a regulating pool. The mathematical model consists of mathematical models of the first-stage power plant, the regulating pool, and the second-stage power plant. The mathematical model of the first-stage power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine. The mathematical model of the regulating pool is the water flow continuity equation. The mathematical model of the second-stage power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine.

[0009] Step 2: Propose a governor control strategy for a series-connected impulse power plant with a regulating pool. Specifically, the governor model for the first-stage power plant adopts a proportional-integral control strategy with the relative value of the power deviation of the first-stage power plant as the input signal, and the control parameter is the proportional gain k. p1 and integral gain k i1 The governor model for the secondary power station adopts a dual proportional-integral control strategy, using the relative values ​​of the power deviation of the secondary power station and the relative values ​​of the water level deviation in the regulating pool as input signals. The control parameter is the proportional gain k of the relative power deviation of the secondary power station. p2 and integral gain k i2 And the proportional gain k of the relative value of the water level deviation in the regulating tank p3 and integral gain k i3 ;

[0010] Step 3: Based on the mathematical models of the primary power station, regulating pool, and secondary power station in Step 1, and the governor models of the primary and secondary power stations in Step 2, establish a stability analysis model for a two-stage series impulse power station including a regulating pool, and propose stability criteria for the series power station.

[0011] Step 4: Based on the momentum equations of the water conveyance tunnel and the impulse turbine established in Step 1, and the governor model of the first-stage power station in Step 2, establish a stability analysis model for the first-stage power station, propose stability criteria for the first-stage power station, and thus determine k. p1 - k i1 Stability region, wherein the x-coordinate of the stability region is k. p1 The vertical axis is k i1 ;

[0012] Step 5: Based on the k obtained in Step 4 p1 - k i1 Stability region, in which k is selected p1 and k i1 and select k p1 and k i1 Substituting this into the stability criterion for the series power station in step three, the control parameter k is determined based on the stability criterion for the series power station. p2 k i2 k p3 k i3 .

[0013] Furthermore, in the mathematical model of the primary power station described in step one, the momentum equation for the water conveyance tunnel is: (1) In the formula: T w1 , q1, h f1 The parameters for the flow inertia constant, relative flow deviation, and head loss of the water conveyance tunnel in the first-stage power station are: H. t1,0 h represents the steady-state head of the impulse turbine in a first-stage power station. t1 This represents the relative value of the head deviation of the impulse turbine in a first-stage power station.

[0014] The equation for the impulse turbine is: (2) (3) In the formula: q t1 μ1, p t1 These are the relative values ​​of flow deviation, needle valve opening deviation, and output deviation for the impulse turbine of the first-stage power station, respectively.

[0015] The continuity equation for the water flow in the regulating tank is: (4) In the formula: F s The area of ​​the equalization tank is z; the relative value of the water level deviation in the equalization tank is z; Q 1,0 H represents the steady-state value of the flow rate in the water conveyance tunnel of the first-stage power station; t2,0 Q represents the steady-state head of the impulse turbine in a secondary power station. 2,0 q1 represents the steady-state value of the flow rate in the secondary power station's water conveyance tunnel; q2 represents the relative value of the flow rate deviation in the secondary power station's water conveyance tunnel.

[0016] In the mathematical model of the secondary power station, the momentum equation of the water diversion tunnel is: (5) In the formula: T w2 h f2 The inertial constant and head loss of the water conveyance tunnel for the secondary power station; h t2 This refers to the relative value of the head deviation of the impulse turbine in a secondary power station.

[0017] The equation for the impulse turbine is: (6) (7) In the formula: q t2 μ2, p t2 These represent the relative values ​​of flow deviation, needle valve opening deviation, and output deviation for the impulse turbine of the secondary power station.

[0018] Furthermore, the model of the primary power plant governor mentioned in step two is as follows: (8) In the formula: k p1 and k i1 These are the proportional gain and integral gain of the relative power deviation of a primary power plant, respectively.

[0019] The model of the secondary power station governor is as follows: (9) In the formula: k p2 and k i2 These are the proportional gain and integral gain of the relative power deviation of the secondary power station, respectively; k p3 and k i3 These are the proportional gain and integral gain of the relative value of the water level deviation in the regulating pool, respectively.

[0020] Furthermore, the stability analysis model of the two-stage series impulse power plant with regulating pool described in step three is obtained by rearranging equations (1)-(9): (10)

[0021] For equation (10), a fifth-order model of the system is established based on state-space theory: (11) In the formula: Here, E is the state variable; and F is the parameter matrix, expressed as: ; ,in: ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;

[0022] Multiply both sides of equation (11) by have to: (12) In the formula: The state matrix A is the core indicator of system stability. The system is stable when all real parts of the eigenvalues ​​of the state matrix A are less than 0; otherwise, the system is unstable.

[0023] Furthermore, the stability analysis model of the primary power plant described in step four is obtained by rearranging equations (1), (2), (3), and (8): (13)

[0024] The characteristic equation of equation (13) is: (14) In the formula: ; .

[0025] According to the Routh-Holwitz stability criterion, the necessary and sufficient condition for a system to be stable is: ( (15)

[0026] Because the head of the first-stage power station is much greater than its head loss, that is... Further simplification of equation (15) yields the stability conditions for a first-stage power plant: (16)

[0027] Substituting the parameters of the primary power station's water conveyance and power generation system into equation (16), we obtain the horizontal axis k. p1 The vertical axis is k i1 k p1 -k i1 Stability region.

[0028] Furthermore, the specific method described in step five is to calculate different k based on the state matrix A in equation (12) of step three. p2 k i2 k p3 k i3 The stability of A is determined by the sign of all eigenvalues ​​of A under the parameter combination, thereby identifying k that satisfies the stability condition. p2 k i2 k p3 k i3 .

[0029] Beneficial effects: The stable control method for power regulation of a two-stage series impulse power plant with regulating pool provided by this invention can not only achieve rapid and stable power regulation of the power plant, but also effectively suppress the water level deviation of the regulating pool and make it tend to be stable. It has the advantages of clear physical meaning and strong engineering applicability, and provides a theoretical basis for ensuring the synchronous and stable operation of series impulse power plants with regulating pool, and has broad application prospects. Attached Figure Description

[0030] Figure 1 A schematic diagram of the layout of a two-stage series impulse power plant water conveyance and power generation system including a regulating pool;

[0031] Figure 2 For k p1 - k i1 Stability region;

[0032] Figure 3 This refers to the dynamic response process of power regulation in a series-connected power plant. Figure 3 In the diagram, (a) shows the dynamic response process of the first-stage power plant; (b) shows the dynamic response process of the regulating reservoir water level; and (c) shows the dynamic response process of the second-stage power plant. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] This invention proposes a stable control method for power regulation of a two-stage series impulse power plant with a regulating pool. The method mainly includes the following five steps.

[0035] Step 1: Establish a mathematical model of a two-stage series impulse power plant system with a regulating pool. The mathematical model consists of a primary power plant, a regulating pool, and a secondary power plant. The primary power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine. The regulating pool has the water flow continuity equation. The secondary power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine.

[0036] Step 2: Propose a speed governor control strategy for a series-connected impulse power plant with a regulating pool. The key feature is that the speed governor of the first-stage power plant adopts a proportional-integral control strategy with the relative value of the power deviation of the first-stage power plant as the input signal, and the control parameter is the proportional gain k. p1 and integral gain k i1 The governor of the secondary power station adopts a dual proportional-integral control strategy, using the relative values ​​of the power deviation of the secondary power station and the relative values ​​of the water level deviation in the regulating pool as input signals. The control parameter is the proportional gain k of the relative power deviation of the secondary power station. p2 and integral gain k i2 And the proportional gain k of the relative value of the water level deviation in the regulating tank p3 and integral gain k i3 .

[0037] Step 3: Based on the mathematical models of the primary power station, regulating pool, and secondary power station in Step 1, and the governor models of the primary and secondary power stations in Step 2, establish a stability analysis model for a two-stage series impulse power station including a regulating pool, and propose stability criteria for the series power station.

[0038] Step 4: Based on the momentum equations of the water conveyance tunnel and the impulse turbine equations of the first-stage power station in Step 1, and the governor equations of the first-stage power station in Step 2, establish a stability analysis model for the first-stage power station, propose stability criteria for the first-stage power station, and thus determine k. p1 - k i1 Stability region, wherein the x-coordinate of the stability region is k. p1 The vertical axis is k i1 .

[0039] Step 5: Based on the k obtained in Step 4 p1 - k i1 Stability region, in which k is selected p1 and k i1 and select k p1 and k i1 Substituting this into the stability criterion for the series power station in step 3, the control parameter k is determined based on the stability criterion for the series power station. p2 k i2 k p3 k i3 .

[0040] Step 1: Establish a mathematical model of a two-stage series impulse power plant system with a regulating pool. The mathematical model consists of a first-stage power plant, a regulating pool, and a second-stage power plant. The first-stage power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine. The regulating pool is represented by the water flow continuity equation. The second-stage power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine.

[0041] Specifically, in step 1, the momentum equation for the water conveyance tunnel of the primary power station is: (1) In the formula: T w1 , q1, h f1 The parameters for the flow inertia constant, relative flow deviation, and head loss of the water conveyance tunnel in the first-stage power station are: H. t1,0 h represents the steady-state head of the impulse turbine in a first-stage power station. t1 This represents the relative value of the head deviation of the impulse turbine in a first-stage power station.

[0042] The equations for the impulse turbine in a first-stage power station are as follows: (2) (3) In the formula: qt1 μ1, p t1 These represent the relative values ​​of flow deviation, needle valve opening deviation, and output deviation for the impulse turbine of the first-stage power station.

[0043] The continuity equation for the water flow in the regulating tank is: (4) In the formula: F s The area of ​​the equalization tank is z; the relative value of the water level deviation in the equalization tank is z; Q 1,0 H represents the steady-state value of the flow rate in the water conveyance tunnel of the first-stage power station; t2,0 Q represents the steady-state head of the impulse turbine in a secondary power station. 2,0 q1 represents the steady-state value of the flow rate in the secondary power station's water conveyance tunnel; q2 represents the relative value of the flow rate deviation in the secondary power station's water conveyance tunnel.

[0044] The momentum equation for the water diversion tunnel of the secondary power station is: (5) In the formula: T w2 h f2 The inertial constant and head loss of the water conveyance tunnel for the secondary power station; h t2 This represents the relative value of the head deviation of the impulse turbine in a secondary power station.

[0045] The equations for the impulse turbine in a two-stage power station are as follows: (6) (7) In the formula: q t2 μ2, p t2 These represent the relative values ​​of flow deviation, needle valve opening deviation, and output deviation for the impulse turbine of the secondary power station.

[0046] Step 2: Propose a power regulation and control strategy for a series-connected impulse power plant with a regulating pool. The strategy is characterized by the use of a proportional-integral control strategy for the speed governor of the first-stage power plant, with the relative value of the power deviation of the first-stage power plant as the input signal. The control parameter is the proportional gain k. p1 and integral gain k i1 The governor of the secondary power station adopts a dual proportional-integral control strategy, using the relative values ​​of the power deviation of the secondary power station and the relative values ​​of the water level deviation in the regulating pool as input signals. The control parameter is the proportional gain k of the relative power deviation of the secondary power station. p2 and integral gain k i2 And the proportional gain k of the relative value of the water level deviation in the regulating tank p3 and integral gain k i3 .

[0047] Specifically, the model of the primary power plant governor is as follows: (8) In the formula: k p1 and k i1 These are the proportional gain and integral gain of the relative power deviation of the primary power plant, respectively.

[0048] The model of the secondary power plant governor is as follows: (9) In the formula: k p2 and k i2 These are the proportional gain and integral gain of the relative power deviation of the secondary power station, respectively; k p3 and k i3 These are the proportional gain and integral gain of the relative value of the water level deviation in the regulating pool, respectively.

[0049] Step 3: Based on the mathematical models of the primary power station, regulating pool, and secondary power station in Step 1, and the governor models of the primary and secondary power stations in Step 2, establish a stability analysis model for a two-stage series impulse power station including a regulating pool, and propose stability criteria for the series power station.

[0050] Specifically, by rearranging equations (1)-(9), the stability analysis model of a two-stage series impulse power plant with a regulating pool can be obtained as follows: (10)

[0051] For equation (10), a fifth-order model of the system can be established based on state-space theory: (11) In the formula: Here, E is the state variable; and F is the parameter matrix, expressed as: ; ,in: ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;

[0052] Multiply both sides of equation (11) by We can obtain: (12) In the formula: The state matrix A is the core indicator reflecting the stability of the system. The system is stable when all real parts of the eigenvalues ​​of the state matrix A are less than 0; otherwise, the system is unstable.

[0053] Step 4: Based on the water conveyance tunnel equations and impulse turbine equations of the first-stage power station in Step 1, and the governor equations of the first-stage power station in Step 2, establish a stability analysis model for the first-stage power station, propose stability criteria for the first-stage power station, and thus determine k. p1 - k i1 Stability region, wherein the x-coordinate of the stability region is k. p1 The vertical axis is k i1 .

[0054] Specifically, by rearranging equations (1), (2), (3), and (8), the stability analysis model for a first-stage power plant can be obtained: (13)

[0055] The characteristic equation of equation (13) is: (14) In the formula: ; .

[0056] According to the Routh-Holwitz stability criterion, the necessary and sufficient condition for a system to be stable is: ( (15)

[0057] Because the head of the first-stage power station is much greater than its head loss, that is... Further simplification of equation (15) yields the stability conditions for a first-stage power plant: (16)

[0058] The following section uses a two-stage series impulse power station with a regulating reservoir as an example to further illustrate this method. The layout diagram of this power station is shown below. Figure 1 The parameters of the water conveyance and power generation system are shown in Table 1. The subscript r in the table indicates the rated operating condition.

[0059] Table 1 Parameters of the Series Hydropower Station Water Conveying and Power Generation System <![CDATA[T w1 (s)]]> 2.548 <![CDATA[Q t1,r (m 3 / s)]]> 100 <![CDATA[h f1 (m)]]> 3 <![CDATA[H t1,r (m)]]> 600 <![CDATA[T w2 (s)]]> 2.039 <![CDATA[Q t2,r (m 3 / s)]]> 100 <![CDATA[h f2 (m)]]> 2 <![CDATA[H t2,r (m)]]> 500 <![CDATA[F s (m 2 )]]> 1000 / /

[0060] The power regulation calculation is performed under the condition of increasing the system load from 90% to 100% of the rated load, as described below. The initial conditions are: First-stage power plant unit head 600.574m, flow rate 89.922m³ / h.3 / s, with a power output of 476.807MW; the secondary power station unit has a head of 500.383m and a flow rate of 89.922m³ / s. 3 The power output is 397.264 MW; the output of the series power station is 874.071 MW. Rated operating conditions are: 600m head and 100m³ / s for the first-stage power station units. 3 / s, with a power output of 529.74MW; the secondary power station unit has a head of 500m and a flow rate of 100m³ / s. 3 / s, with a power output of 441.45 MW; the series power station output is 971.19 MW. Based on the final state, the initial state parameters are dimensionlessly processed to obtain the dimensionless parameters of the system's initial state as follows: .

[0061] Substituting the above parameters into equation (16), we can obtain the x-coordinate as k. p1 The vertical axis is k i1 k p1 - k i1 Stability region, such as Figure 2 As shown.

[0062] Step 5: Based on the k obtained in Step 4 p1 - k i1 Stability region, in which k is selected p1 and k i1 and select k p1 and k i1 Substituting this into the stability criterion for the series power station in step 3, the control parameter k is determined based on the stability criterion for the series power station. p2 k i2 k p3 k i3 .

[0063] Specifically, based on the state matrix A in equation (12) of step 3, calculate different k p2 k i2 k p3 k i3 The stability of A is determined by the sign of all eigenvalues ​​of A under the parameter combination, thereby identifying k that satisfies the stability condition. p2 k i2 k p3 k i3 .

[0064] To further demonstrate the correctness of this method, the control parameter k within the stability region in step 4 is first selected using the above method. p1 and k i1 The values ​​were 0.2 and 0.4 s, respectively. -1Substitute it into the state matrix A in equation (12), and determine the k that satisfies the stability condition according to the stability condition. p2 k i2 k p3 k i3 The values ​​were 0.2 and 0.4 s, respectively. -1 1, 6 s -1 .

[0065] To further illustrate the control strategy and its correctness, a fourth-order Runge-Kutta method was used to numerically simulate the dynamic process of power regulation in a series power plant. The results are shown in [Figure number missing]. Figure 3 (a) and Figure 3 (b).

[0066] Depend on Figure 3 (a) It can be seen that the dynamic responses of flow rate, power, and guide vane opening of the first-stage power station gradually converge, therefore the first-stage power station is stable; the dynamic response of the regulating pool water level gradually converges, therefore the regulating pool water level is stable; the dynamic responses of flow rate, power, and guide vane opening of the second-stage power station gradually converge, therefore the second-stage power station is stable. In summary, the proposed control strategy and control parameter selection method can effectively ensure the stability of power regulation in series power stations.

[0067] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A stable control method for a two-stage series-connected impulse power regulation system for a power plant, characterized in that, Includes the following steps: Step 1: Establish a mathematical model of a two-stage series impulse power plant system with a regulating pool. The mathematical model consists of mathematical models of the first-stage power plant, the regulating pool, and the second-stage power plant. The mathematical model of the first-stage power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine. The mathematical model of the regulating pool is the water flow continuity equation. The mathematical model of the second-stage power plant includes the momentum equation of the water conveyance tunnel and the equation of the impulse turbine. Step 2: Propose a governor control strategy for a series-connected impulse power plant with a regulating pool. Specifically, the governor model for the first-stage power plant adopts a proportional-integral control strategy with the relative value of the power deviation of the first-stage power plant as the input signal, and the control parameter is the proportional gain k. p1 and integral gain k i1 The governor model for the secondary power station adopts a dual proportional-integral control strategy, using the relative values ​​of the power deviation of the secondary power station and the relative values ​​of the water level deviation in the regulating pool as input signals. The control parameter is the proportional gain k of the relative power deviation of the secondary power station. p2 and integral gain k i2 And the proportional gain k of the relative value of the water level deviation in the regulating tank p3 and integral gain k i3 ; Step 3: Based on the mathematical models of the primary power station, regulating pool, and secondary power station in Step 1, and the governor models of the primary and secondary power stations in Step 2, establish a stability analysis model for a two-stage series impulse power station including a regulating pool, and propose stability criteria for the series power station. Step 4: Based on the momentum equations of the water conveyance tunnel and the impulse turbine established in Step 1, and the governor model of the first-stage power station in Step 2, establish a stability analysis model for the first-stage power station, propose stability criteria for the first-stage power station, and thus determine k. p1 - k i1 Stability region, wherein the x-coordinate of the stability region is k. p1 The vertical axis is k i1 ; Step 5: Based on the k obtained in Step 4 p1 - k i1 Stability region, in which k is selected p1 and k i1 and select k p1 and k i1 Substituting this into the stability criterion for the series power station in step three, the control parameter k is determined based on the stability criterion for the series power station. p2 k i2 k p3 k i3 .

2. The stable control method for power regulation of a two-stage series-connected impulse power plant with a regulating pool according to claim 1, characterized in that, In the mathematical model of the first-stage power station described in step one, the momentum equation for the water conveyance tunnel is: (1) In the formula: T w1 , q1, h f1 The parameters for the flow inertia constant, relative flow deviation, and head loss of the water conveyance tunnel in the first-stage power station are: H. t1,0 h represents the steady-state head of the impulse turbine in a first-stage power station. t1 This represents the relative value of the head deviation of the impulse turbine in a first-stage power station. The equation for the impulse turbine is: (2) (3) In the formula: q t1 μ1, p t1 These are the relative values ​​of flow deviation, needle valve opening deviation, and output deviation for the impulse turbine of the first-stage power station, respectively. The continuity equation for the water flow in the regulating tank is: (4) In the formula: F s The area of ​​the equalization tank is z; the relative value of the water level deviation in the equalization tank is z; Q 1,0 H represents the steady-state value of the flow rate in the water conveyance tunnel of the first-stage power station; t2,0 Q represents the steady-state head of the impulse turbine in a secondary power station. 2,0 q1 represents the steady-state value of the flow rate in the secondary power station's water conveyance tunnel; q2 represents the relative value of the flow rate deviation in the secondary power station's water conveyance tunnel. In the mathematical model of the secondary power station, the momentum equation of the water conveyance tunnel is: (5) In the formula: T w2 h f2 The inertial constant and head loss of the water conveyance tunnel for the secondary power station; h t2 This refers to the relative value of the head deviation of the impulse turbine in a secondary power station. The equation for the impulse turbine is: (6) (7) In the formula: q t2 μ2, p t2 These represent the relative values ​​of flow deviation, needle valve opening deviation, and output deviation for the impulse turbine of the secondary power station.

3. The stable control method for power regulation of a two-stage series-connected impulse power plant with a regulating pool according to claim 2, characterized in that, The model of the primary power plant governor mentioned in step two is as follows: (8) In the formula: k p1 and k i1 These are the proportional gain and integral gain of the relative power deviation of a primary power plant, respectively. The model of the secondary power station governor is as follows: (9) In the formula: k p2 and k i2 These are the proportional gain and integral gain of the relative power deviation of the secondary power station, respectively; k p3 and k i3 These are the proportional gain and integral gain of the relative value of the water level deviation in the regulating pool, respectively.

4. The stable control method for power regulation of a two-stage series-connected impulse power plant with a regulating pool according to claim 3, characterized in that, The stability analysis model of the two-stage series impulse power plant with regulating pool described in step three is obtained by rearranging equations (1)-(9): (10) For equation (10), a fifth-order model of the system is established based on state-space theory: (11) In the formula: Here, E is the state variable; and F is the parameter matrix, expressed as: ; ,in: ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Multiply both sides of equation (11) by have to: (12) In the formula: The state matrix A is the core indicator of system stability. The system is stable when all real parts of the eigenvalues ​​of the state matrix A are less than 0; otherwise, the system is unstable.

5. The stability control method for a two-stage series-connected impulse power regulation power plant with a regulating pool according to claim 4, characterized in that, The stability analysis model of the primary power plant described in step four is obtained by rearranging equations (1), (2), (3), and (8): (13) The characteristic equation of equation (13) is: (14) In the formula: ; ; According to the Routh-Holwitz stability criterion, the necessary and sufficient condition for a system to be stable is: ( ) (15) Because the head of the first-stage power station is much greater than its head loss, that is... Further simplification of equation (15) yields the stability conditions for a first-stage power plant: (16) Substituting the parameters of the primary power station's water conveyance and power generation system into equation (16), we obtain the horizontal axis k. p1 The vertical axis is k i1 k p1 - k i1 Stability region.

6. The stable control method for power regulation of a two-stage series-connected impulse power plant with a regulating pool according to claim 5, characterized in that, The specific method of step five is to calculate different k based on the state matrix A in equation (12) of step three. p2 k i2 k p3 k i3 The stability of A is determined by the sign of the real parts of all eigenvalues ​​of A under the parameter combination, thereby identifying k that satisfies the stability condition. p2 k i2 k p3 k i3 .

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