CN104298806A - Hydropower station dynamic property computer-assisted testing method - Google Patents

Abstract

A computer-aided testing method for the dynamic characteristics of a hydropower station, the method comprising the following steps: 1), obtaining fuzzy dynamic characteristic data from the comprehensive characteristic curve of operation, and obtaining the flow output dynamic characteristic equation in the dynamic characteristic curve of the hydropower station; 2), fuzzy dynamic characteristic data Processing: trace the data measured under different water heads on the grid paper, set the vertical axis of the graph paper as the flow rate of the turbine, and set the horizontal axis as the power of the turbine, and then set the average water head of the turbine to 3) The computer-aided drawing of the dynamic characteristic curve of the hydropower station obtains the dynamic characteristic curve of the hydropower station. The invention aims at the operation comprehensive characteristic curve of the water turbine, acquires the dynamic characteristic data, and performs data processing to realize the dynamic characteristic test of the hydropower station.

Description

A computer-aided test method for hydropower station dynamic characteristics

technical field

The invention relates to the field of economic operation of a hydropower station, in particular to a computer-aided testing method for the dynamic characteristic curve of a hydropower station.

Background technique

The dynamic characteristic of hydropower station is an important content in the economic operation of hydropower station. The dynamic characteristic curve of a hydropower station is used to represent the energy change and loss characteristics of a hydropower station when water energy is converted into electric energy. The dynamic characteristic curve of the hydropower station can be used to study the hydraulic performance of the hydropower station at the moment, and also provide a basis for formulating the optimal distribution of active load of the hydropower station.

At present, the equipment of rural hydropower stations is backward. Most of the hydropower stations have not done real machine tests. They only formulate the optimal operation mode of hydropower stations according to the data provided by the purchased water equipment manufacturers. The results obtained deviate greatly from the actual optimal method of the power station.

Contents of the invention

In order to overcome the inability to test the dynamic characteristic curve of the existing hydropower station, the present invention provides a computer-aided testing method for the dynamic characteristic of the hydropower station by acquiring the dynamic characteristic data and processing the data for the comprehensive characteristic curve of the operation of the hydraulic turbine.

The technical solution adopted by the present invention to solve its technical problems is as follows:

A computer-aided testing method for the dynamic characteristics of a hydropower station, the method comprising the following steps:

1) Obtain fuzzy dynamic characteristic data from the comprehensive characteristic curve of operation

To obtain the flow output power dynamic characteristic equation in the dynamic characteristic curve of the hydropower station, the specific steps are as follows:

(1.1) On the comprehensive operating characteristic curve of the water turbine, when the water head H _j is a certain value, draw a number of straight lines parallel to the horizontal axis N, and read out the output force P _j and The corresponding efficiency η _j values are then brought into the following formula

${\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}{{\mathrm{<span\; class="notranslate">\; 9.81</span>}\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

According to the above method, the corresponding output force P _j and the corresponding efficiency η _j value under a certain water head are obtained, and then a curve equation about Q～P _j (H _j ) is obtained according to the least square method fitting principle; similarly, for other different According to this method, the corresponding Q～P _j (H _j ) curve equations can also be obtained for the water head H _j value, which will constitute the corresponding Q～P _j (H _j ) equations;

(1.2), on the basis of the Q～P _j (H _j ) equations obtained in step (1.1), draw a horizontal line parallel to the flow rate Q ₁ to intersect the curve of the equal water head H _j , and the corresponding H _j and P _j values; according to this set of H _j and P _j values, you can add an equal flow line on the comprehensive operating characteristic curve of the turbine; according to the method in (1.2), the comprehensive operating characteristic of the hydraulic turbine Many isokinetic lines are obtained on the curve;

(1.3) Select several flow rates Q ₁ , Q ₂ , Q ₃ ... on the comprehensive operating characteristic curve of the turbine, and the head of the unit section of the turbine is H _d1 ; Loss characteristic (ΔH～Q) curve, for each selected flow rate Q, the corresponding water head loss of the corresponding drinking water pipe ΔH ₁ , ΔH ₂ , ΔH ₃ ... Finally, according to the hydraulic turbine head calculation formula H _j1 ＝H _d1 - ΔH ₁ is to get the head value corresponding to the corresponding flow Q;

(1.4), according to the value of _Hj1 and corresponding _Q1 obtained in the step (1.3), obtain the corresponding water turbine unit output _Pj1 value according to the water turbine integrated operating characteristic curve provided, according to the formula P ₁ =η _d . P _j1 can calculate the unit output P _j1 value, generator efficiency η _d can be obtained from the generator efficiency curve; similarly, for the rest of the flow Q ₂ , Q ₃ , Q ₄ ..., also use the same method to obtain the same value as The corresponding output values of turbine units P ₂ , P ₃ , P ₄ ...;

2) Processing of fuzzy dynamic characteristic data

The data measured under different water heads are traced on the coordinate graph paper. The vertical axis of the graph paper is set as the flow rate of the turbine, and the horizontal axis is set as the power of the turbine. Then Q, P, H dynamic characteristics;

3) Computer-aided drawing of the dynamic characteristic curve of the hydropower station

Input the original data of water head H _d , flow Q, turbine output N and unit power loss of the turbine unit section.

Use the least square method to fit the known dynamic characteristic data under the water head, and obtain the relationship between output and water consumption rate and q ₀ =f(N,H), the function between output and power loss under each water head The relationship ΔN=f(N,H), the mathematical function relationship between output and flow Q=f(N,H), the general expression of the fitting curve is:

f(N,H)＝a ₀ +a ₁ N+a ₂ N ² +......+a _n N ⁿ

Then derivate ΔN=f(N,H) to obtain value, and finally use the least squares method to fit the output and the micro-increase rate, and get The expression of the hydropower station dynamic characteristic curve is obtained.

The working principle of the present invention: the present invention aims at the comprehensive characteristic curve of hydropower station operation, acquires fuzzy dynamic characteristic data, uses the centroid method to process the data, and proposes the steps of computer-aided drawing of the dynamic characteristic curve.

The beneficial effects of the present invention are as follows: 1. Obtain fuzzy dynamic characteristic data for the comprehensive characteristic curve of hydropower station operation; 2. Perform data processing on the fuzzy dynamic characteristic data of hydropower station; 3. Propose the steps of computer-aided drawing of dynamic characteristic curve, and finally The program block diagram of the computer drawing of the dynamic characteristic curve is given; 4. The invented method is easy to realize on the computer; 5. The obtained result is scientific and reasonable.

Description of drawings

Fig. 1 is a flowchart of a computer-aided testing method for the dynamic characteristics of a hydropower station.

Figure 2 is a comprehensive characteristic curve diagram of hydropower station operation.

Fig. 3 is a graph of dynamic characteristics drawn by computer aids.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

With reference to Fig. 1～Fig. 3, a kind of hydropower station dynamic characteristic computer-aided testing method, this method comprises the following steps:

1) Obtain fuzzy dynamic characteristic data from the comprehensive characteristic curve of operation

To obtain the flow output power dynamic characteristic equation in the dynamic characteristic curve of the hydropower station, the specific steps are as follows:

(1.1) On the comprehensive operating characteristic curve of the water turbine, when the water head H _j is a certain value, draw a number of straight lines parallel to the horizontal axis N, and read out the output force P _j and The corresponding efficiency η _j values are then brought into the following formula

${\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}{{\mathrm{<span\; class="notranslate">\; 9.81</span>}\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

According to the above method, the corresponding output force P _j and the corresponding efficiency η _j value under a certain water head are obtained, and then a curve equation about Q～P _j (H _j ) is obtained according to the least square method fitting principle; similarly, for other different According to this method, the corresponding Q～P _j (H _j ) curve equations can also be obtained for the water head H _j value, which will constitute the corresponding Q～P _j (H _j ) equations;

(1.2), on the basis of the Q～P _j (H _j ) equations obtained in step (1.1), draw a horizontal line parallel to the flow rate Q ₁ to intersect the curve of the equal water head H _j , and the corresponding H _j and P _j values; according to this set of H _j and P _j values, you can add an equal flow line on the comprehensive operating characteristic curve of the turbine; according to the method in (1.2), the comprehensive operating characteristic of the hydraulic turbine Many isokinetic lines are obtained on the curve;

(1.3) Select several flow rates Q ₁ , Q ₂ , Q ₃ ... on the comprehensive operating characteristic curve of the turbine, and the head of the unit section of the turbine is H _d1 ; Loss characteristic (ΔH～Q) curve, for each selected flow rate Q, the corresponding water head loss of the corresponding drinking water pipe ΔH ₁ , ΔH ₂ , ΔH ₃ ... is best calculated according to the hydraulic turbine head calculation formula H _j1 = H _d1 -ΔH ₁ is to get the head value corresponding to the corresponding flow Q;

(1.4), according to the value of _Hj1 and corresponding _Q1 obtained in the step (1.3), obtain the corresponding water turbine unit output _Pj1 value according to the water turbine integrated operating characteristic curve provided, according to the formula P ₁ =η _d . P _j1 can calculate the unit output P _j1 value, generator efficiency η _d can be obtained from the generator efficiency curve; similarly, for the rest of the flow Q ₂ , Q ₃ , Q ₄ ..., also use the same method to obtain the same value as The corresponding output values of turbine units P ₂ , P ₃ , P ₄ ...;

2) Processing of fuzzy dynamic characteristic data

Theoretically, the dynamic characteristic curves of hydropower turbine units are required not to intersect with each other under different water heads, but the measured data sometimes cannot fully meet this requirement due to data distortion or instrument error, and some discarding and corrections are required at this time. The "centroid method" is a popular method for video data and audio data processing in recent years. Many studies and practical processing have shown that this method has achieved good results in data rationality and consistency testing. The "centroid method" can be used for data processing, and the detailed steps are as follows: trace the data measured under different water heads on the coordinate graph paper, set the vertical axis of the graph paper as the flow rate of the turbine, and set the horizontal axis as The power of the water turbine, and then the dynamic characteristics such as Q, P, and H under the average water head of the water turbine. According to theoretical analysis, the dynamic characteristics under the average water head are similar to those of other water heads, that is, there is an approximate trend, and there is a certain distance between them, and this distance increases with the increase of power. In this way, using the original measured data to make corrections according to this general trend can exclude those obviously unreasonable data.

3) Computer-aided drawing of the dynamic characteristic curve of the hydropower station

Input the original data related to the water head (H _d ), flow rate (Q) of the unit section of the turbine, the output of the turbine (N), the unit and the power loss of the unit.

Using the least square method to fit the known dynamic characteristic data under the water head, the relationship between output and water consumption rate and q ₀ =f(N,H), the relationship between output and power loss at each water head can be obtained The functional relationship ΔN=f(N,H), the mathematical functional relationship between output and flow Q=f(N,H). The general expression of the fitted curve is:

f(N,H)＝a ₀ +a ₁ N+a ₂ N ² +......+a _n N ⁿ

Then, the derivative of ΔN=f(N,H) can be obtained under different water heads value, and finally use the least squares method to fit the output and micro-increasing rate, we can get The expression of the hydropower station dynamic characteristic curve is obtained.

Claims (1)

1. a power station dynamic characteristic calculation machine auxiliary test methods, is characterized in that: the method comprises the steps:

1), fuzzy kinematic behavior data are obtained from running combined characteristic

The flow obtained in power station dynamic characteristic curves is exerted oneself kinematic behavior equation, and concrete steps are as follows:

(1.1), on the comprehensive service performance curve of the hydraulic turbine, as head H _jduring for certain certain value, draw the straight line that many are parallel to transverse axis N, read the P that the exerts oneself during intersection point of these straight lines and isoefficiency curve _jwith corresponding efficiency eta _jvalue, and then bring in following formula

$Q_j=\frac{P_j}{{9.81H}_j{\mathrm{\&eta;}}_j}---\left(1\right)$

Exert oneself under obtaining a certain head according to said method P accordingly _jwith corresponding efficiency eta _jvalue, then obtains one about Q ~ P according to least square fitting principle _j(H _j) curvilinear equation; In like manner, for other different head H _jvalue also obtains corresponding Q ~ P according to the method _j(H _j) curvilinear equation, they will form corresponding Q ~ P _j(H _j) system of equations;

(1.2), in Q ~ P that step (1.1) obtains _j(H _j) on system of equations basis, add and paint a rule and be parallel to flow Q ₁horizontal line with wait head H _jcurve line intersect, corresponding H can be obtained by intersection point _jand P _jvalue; According to this group H _jand P _jnumerical value, just can add and paint a line such as flow such as grade on the comprehensive service performance curve of the hydraulic turbine; In like manner obtain much waiting flow line on the comprehensive service performance curve of the hydraulic turbine according to the method in (1.2);

(1.3), on the comprehensive service performance curve of the hydraulic turbine, several flows Q is chosen ₁, Q ₂, Q ₃, now the unit section head of the hydraulic turbine is H _d1; According to calculation of head losses formula, or penstock loss of flood peak characteristic (Δ H ~ Q) curve of the hydraulic turbine, for the flow Q that each is selected, just obtain the corresponding loss of flood peak Δ H of corresponding water drinking tube ₁, Δ H ₂, Δ H ₃preferably according to hydraulic turbine head computing formula H _j1=H _d1-Δ H ₁namely the head value that corresponding flow Q is corresponding is obtained;

(1.4), according to the H obtained in step (1.3) _j1and corresponding Q ₁value, to exert oneself P according to the hydraulic turbine comprehensive service performance curve that provides obtaining corresponding water turbine set _j1value, according to formula P ₁=η _dp _j1unit output P can be calculated _j1value, efficiency of generator η _defficiency of generator curve obtains; In like manner, for remaining flow Q ₂, Q ₃, Q ₄, also use the same method and try to achieve the water turbine units corresponded and go out force value P ₂, P ₃, P ₄

2), the process of fuzzy kinematic behavior data

Grid square paper is retouched data measured under different head, and the longitudinal axis of square paper is set as that the flow of the hydraulic turbine, transverse axis are set as the power of the hydraulic turbine, then by Q, P, H kinematic behavior under the average water head of the hydraulic turbine;

3), power station dynamic characteristic curves Computer Aided Drawing

Input water turbine units section head H _d, flow Q, output of hydraulic turbine N and the power of the assembling unit loss raw data;

Kinematic behavior data under the head known with least square fitting, under obtaining each head, exert oneself and relation between water consumption rate and q ₀=f (N, H), exerts oneself and funtcional relationship Δ N=f (N, H) between power loss, and exert oneself and mathematical function relationship Q=f (N, H) between flow, the expression general formula of matched curve is:

f(N,H)＝a ₀+a ₁N+a ₂N ²+......+a _nN ⁿ

Then carry out under differentiate obtains different head to Δ N=f (N, H) value, finally exert oneself and tiny increment with least square fitting, obtain expression formula, namely obtain power station dynamic characteristic curves.