A test method for testing primary frequency modulation function

Abstract

The present invention discloses a test method for testing a primary frequency modulation function, which converts the test index into a grid area according to the test site capacity and the test disturbance frequency; forms a test power curve P in the grid area according to the test data. 测试 ; According to the test power curve P 测试 The intersection with the grid area is used to determine whether the result of the primary frequency modulation action meets the requirements. By converting the test indicators into a grid P‑t curve according to the test site capacity and the test disturbance frequency and dividing each area, it is quickly determined whether the result of the primary frequency modulation action meets the requirements according to the distribution of the test data in the grid area. This method is suitable for the rapid determination of the test results of the primary frequency modulation function of new energy units. The present invention can be effectively used for the determination of the frequency step test results of the primary frequency modulation on-site. The determination result has a high accuracy rate, and the time for determining the on-site test indicators is greatly shortened, thereby improving the efficiency of on-site testing.

Description

Technical Field

[0001] The invention belongs to the technical field of new energy grid-connected detection, and in particular belongs to a test method for testing a primary frequency modulation function. Background Art

[0002] Energy plays an indispensable role in the development of modern society. After large-capacity and high-proportion new energy sources were concentratedly connected to the power grid, the power supply structure has undergone great changes. The proportion of traditional power grid frequency response resources has gradually decreased, and the frequency regulation pressure and safe operation risks have continued to increase. There is an urgent need for new energy to participate in the rapid response of the power grid and improve the level of frequency risk prevention and control in large power grids.

[0003] Frequency is an important parameter of the power supply quality indicator for power users. In order to ensure the safe and stable operation of the power grid and improve the frequency power supply quality of the power grid, the power grid currently requires grid-connected power plants to have a certain primary frequency regulation capability and requires the acceptance of this function through on-site testing. The relevant standards and regulations have clarified the verification test methods for the frequency regulation function of various types of grid-connected units, and all require the use of frequency steps on-site to verify the primary frequency regulation function of the grid-connected units. The primary frequency regulation test of new energy stations is an emerging business. There are currently a large number of stations to be put into operation, and the primary frequency regulation test task is arduous. Therefore, a method for quickly judging the on-site test situation is of great significance to accelerate the investment in the primary frequency regulation function of new energy stations. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a test method for testing a primary frequency modulation function, which greatly simplifies the calculation of result determination, can improve the efficiency of on-site test on the determination of test results, and the determination method is simple and easy to implement.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A test method for testing a primary frequency modulation function, converting the test index into a grid area according to the test site capacity and the test disturbance frequency;

[0007] According to the test data, a test power curve P is formed in the grid area. 测试 ;

[0008] According to the test power curve P 测试 The intersection with the grid area determines whether the result of a frequency modulation action meets the requirements.

[0009] Preferably, the test indicators include start-up time, response time, regulation time and regulation power error.

[0010] Preferably, the action dead zone of the primary frequency modulation function is ±0.05Hz, the start-up time is no more than 3s, the response time is no more than 10s, the adjustment time is no more than 15s, and the adjustment power error is ±2%P n .

[0011] Furthermore, the response time of the wind farm is 10s, and the response time of the photovoltaic power station is 5s.

[0012] Preferably, the horizontal axis of the grid area is divided according to ΔP, and the calculation formula of ΔP is:

[0013]

[0014] In the formula, △p is the active power regulation; f is the test frequency; f d is the primary frequency modulation dead zone; f n is the system rated frequency; P n is the rated power of the new energy station; δ% is the primary frequency regulation coefficient of the new energy station.

[0015] Further, the horizontal axis curves of the grid area are 10% △P, horizontal axis I, 90% △P, 100% △P, and horizontal axis II;

[0016] Horizontal axis I = P0 + △P + 0.02*P n ;

[0017] Horizontal axis II = P0 + △P - 0.02*P n .

[0018] Furthermore, the test power curve P is output in the same coordinate 测试 And the grid determination Pt curve P in the corresponding time 判断 The criteria are as follows:

[0019] If the test power curve P 测试 If the intersection point with the 10%△P horizontal axis curve is on the left side of the 3s vertical axis curve, the start-up time is qualified, otherwise it is unqualified;

[0020] If the test power curve P 测试 If the intersection of the horizontal axis curve with 90% △P is on the left side of the vertical axis curve of 10s, the response time is qualified, otherwise it is unqualified;

[0021] If the test power curve P 测试 If all are within the area between horizontal axis Ⅰ and horizontal axis Ⅱ, the adjustment time and adjustment error are qualified, otherwise they are unqualified.

[0022] Preferably, the test power curve P 测试 It is the power curve when the frequency f exceeds the primary frequency modulation dead time.

[0023] Preferably, the specific steps of the discrimination method are:

[0024] Step 1: Input the installed capacity P of the station to be tested n , test frequency f 测试 , test data x n ;

[0025] Step 2: Output the test power curve P in the same coordinates 测试 And the grid determination Pt curve P in the corresponding time 判断 ;

[0026] Step 3: Determine the test power curve P 测试 The intersection point with 10%△P horizontal axis, if the intersection point is on the left side of 3s vertical axis, the start time is qualified, if the intersection point is on the right side of 3s vertical axis, the start time is unqualified;

[0027] Step 4: Determine the test power curve P 测试 The intersection point with 90%△P horizontal axis, if the intersection point is on the left side of 10s vertical axis, the response time is qualified; if the intersection point is on the right side of 10s vertical axis, the response time is unqualified;

[0028] Step 5: Determine the test power curve P 测试 , if both are within P0+△P+0.02*P n Below the horizontal axis Ⅰ and P0+△P-0.02*P n In the area on the horizontal axis II, the adjustment time is qualified and the adjustment power error is qualified;

[0029] Step 6: Output the determination result.

[0030] Furthermore, in step 1, the first active power data corresponding to the frequency f≥50.05 or f≤49.95 in the test data is set as the initial power P0.

[0031] Compared with the prior art, the present invention has the following beneficial technical effects:

[0032] A method for quickly determining the primary frequency regulation function of a new energy station based on grid regionalization, by converting the test index into a grid Pt curve according to the test station capacity and the test disturbance frequency and dividing each area, and quickly determining whether the primary frequency regulation action result meets the requirements according to the distribution of the test data in the grid area. This method is suitable for the rapid determination of the primary frequency regulation function test results of new energy units. The present invention can be effectively used for the determination of the frequency step test results of the primary frequency regulation on site, with high accuracy of the determination result, and greatly shortening the time for determining the on-site test index, thereby improving the efficiency of on-site testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Principle structure flow chart;

[0034] Figure 2 Description of the Pt curve diagram of the grid regionalization of the primary frequency modulation index;

[0035] Figure 3 Example 1 Grid regionalization pf curve judgment diagram (qualified);

[0036] Figure 4 Example 2: Grid regionalized pf curve judgment diagram (unqualified). DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0038] The present invention provides a method for quickly determining the primary frequency regulation function of a new energy station based on grid regionalization. For the frequency step test index of the primary frequency regulation test, the method converts the test index (start-up time, response time, adjustment time, adjustment error, etc.) into a grid curve according to the test station capacity and the test disturbance frequency, and divides the areas into different areas. According to the distribution of the test data in the grid area, it is quickly determined whether the primary frequency regulation action result meets the requirements.

[0039] The specific steps of the discrimination method are:

[0040] (1) Input the installed capacity Pn of the tested station, the test frequency ftest, and the test data xn (including frequency, active power, and other information), and set the first active power data corresponding to the frequency f≥50.05 or f≤49.95 in the test data as the initial power P0.

[0041] (2) Output test power curve P in the same coordinate 测试 (Power curve when frequency f exceeds the dead zone of primary frequency modulation) and grid determination Pt curve P within the corresponding time 判断 .

[0042] (3) Determine P 测试 If the intersection point is on the left side of the 3s vertical axis (i.e. the intersection point is within area ①), the start-up time is qualified. If the intersection point is on the right side of the 3s vertical axis (i.e. the intersection point is within area ②), the start-up time is unqualified.

[0043] (4) Determine P 测试 If the intersection point is on the left side of the 10s vertical axis (i.e. the intersection point is within area ②), the response time is qualified. If the intersection point is on the right side of the 10s vertical axis (i.e. the intersection point is within area ③), the response time is unqualified.

[0044] (5) Determine the P in area ④ 测试If the curve is on the horizontal axis Ⅰ (P0+△P+0.02*P n horizontal axis) and horizontal axis II (P0+△P-0.02*P n If the adjustment time is within area ⑤ on the horizontal axis, the adjustment error is qualified.

[0045] (6) Output the judgment results: start-up time passed / failed, response time passed / failed, adjustment time passed / failed, and adjustment power error passed / failed.

[0046] Primary frequency modulation test indicator grid area

[0047] The primary frequency modulation dead zone is set according to relevant standards and technical requirements. The primary frequency modulation dead zone means that when the actual frequency f is greater than (50+0.05) Hz or f is less than (50-0.05) Hz, the primary frequency modulation function is activated. The primary frequency modulation action dead zone is ±0.05Hz, the startup time is no more than 3s, the response time is no more than 10s (or 5s, the response time requirement for wind farms is 10s, and the response time requirement for photovoltaic power plants is 5s), the adjustment time is no more than 15s, and the active power adjustment error is ±2%P n .

[0048] According to the primary frequency regulation index and the installed capacity of the tested station P n The grid regionalized Pt curve is outputted at the test frequency f. The active power corresponding to the frequency exceeding the dead zone of the frequency modulation action in the test data is set to P0, and the active power corresponding to the frequency exceeding the dead zone of the frequency modulation action in the test data and then returning to the dead zone of the frequency modulation action is set to P 截至 According to formula (1) and formula (2), the 10% △P horizontal axis curve is output, and the start-up time 3s vertical axis curve is output at the same time, and the 0s-3s interval is set as area ①.

[0049]

[0050] P 10％△P =P0+0.1*△P (2)

[0051] In the above formula, △p is the active power regulation; f d is the primary frequency modulation dead zone, in Hz; f n is the rated frequency of the system, which is 50Hz; P n is the rated power of the new energy station, in MW; δ% is the primary frequency regulation coefficient of the new energy station;

[0052] According to formula (1) and formula (3), the 90% △P horizontal axis curve is output, and the response time 10s vertical axis curve is output at the same time, and the 3s-10s interval is set as area ②.

[0053] P90％△P =P0+0.9*△P (3)

[0054] According to formula (1), formula (4), and formula (5), the horizontal axis I of the upper limit curve of the adjustment error and the horizontal axis II of the lower limit curve of the adjustment error are output, and at the same time, the vertical axis curve of the adjustment time 15s, P 截至 The corresponding time axis curve t n . Set the 10s-15s interval as area ③, and set the 15s- n Set the interval to area ④, and set the horizontal axis Ⅰ, horizontal axis Ⅱ, 15s vertical axis curve, t n The area enclosed by the vertical axis curve is set as area ⑤.

[0055] P 横轴线Ⅰ =P0+△P+0.02*P n (4)

[0056] P 横轴线Ⅱ =P0+△P-0.02*P n (5)

[0057] 2. Criteria Setting

[0058] Output test power curve P in the same coordinate 测试 (Power curve when frequency f exceeds the dead zone of primary frequency modulation) and grid determination Pt curve P within the corresponding time 判断 . Set the following criteria in sequence:

[0059] (1) If P 测试 If the intersection of the curve and the 10%△P horizontal axis curve is on the left side of the 3s vertical axis curve, the start-up time is qualified, otherwise it is unqualified.

[0060] (2) If P 测试 If the intersection of the curve and the 90%△P horizontal axis curve is on the left side of the 10s vertical axis curve, the response time is qualified, otherwise it is unqualified.

[0061] (3) If 15s—t n P in the interval 测试 If all the curves are within area ⑤, the adjustment time and adjustment error are qualified, otherwise they are unqualified.

[0062] Example 1: Taking the actual test data on site as an example, testing the wind farm P n The test power curve P is output in the same coordinate according to this method. 测试 And the grid determination Pt curve in the corresponding time. The results are as follows Figure 3 As shown, it can be seen that intersection 1 is located on the left side of the 3s time axis, intersection 2 is located on the left side of the 10s time axis, and at 15s-t n P in the interval测试 The curve is within the range of area ⑤. It can be concluded that the start-up time, response time, adjustment time, power adjustment error of the test curve meet the requirements, and the primary frequency modulation function meets the requirements.

[0063] Example 2: Taking the actual test data on site as an example, test the wind farm P n The test power curve P is output in the same coordinate according to this method. 测试 And the grid determination Pt curve in the corresponding time. The results are as follows Figure 4 As shown, it can be seen that intersection 1 is on the left side of the 3s time axis, intersection 2 is on the right side of the 10s time axis, and at 15s-t n P in the interval 测试 The curve is within the range of area ⑤. It can be concluded that the start-up time, adjustment time, and power adjustment error of the test curve meet the requirements, but the response time does not meet the requirements, and the primary frequency modulation function does not meet the requirements.

Claims

1. A test method for testing a primary frequency modulation function, characterized in that: Convert the test indicators into grid areas according to the test site capacity and test disturbance frequency; According to the test data, a test power curve P is formed in the grid area. 测试 ; According to the test power curve P 测试 The intersection with the grid area determines whether the result of a frequency modulation action meets the requirements; The specific steps of the determination method are: Step 1: Input the installed capacity P of the station to be tested n , test frequency f 测试 , test data x n ; Step 2: Output the test power curve P in the same coordinates 测试 And the grid determination Pt curve P in the corresponding time 判断 ; Step 3: Determine the test power curve P 测试 The intersection point with 10%△P horizontal axis, if the intersection point is on the left side of 3s vertical axis, the start time is qualified; if the intersection point is on the right side of 3s vertical axis, the start time is unqualified; Step 4: Determine the test power curve P 测试 The intersection point with 90%△P horizontal axis, if the intersection point is on the left side of 10s vertical axis, the response time is qualified; if the intersection point is on the right side of 10s vertical axis, the response time is unqualified; Step 5: Determine the test power curve P 测试 , if both are within P0+△P+0.02*P n Below the horizontal axis Ⅰ and P0+△P-0.02*P n In the area on the horizontal axis II, the adjustment time is qualified and the adjustment power error is qualified; Step 6: Output the determination result.

2. A test method for testing a primary frequency modulation function according to claim 1, characterized in that: The test indicators include start-up time, response time, regulation time and regulation power error.

3. A test method for testing a primary frequency modulation function according to claim 1, characterized in that: The action dead zone of primary frequency modulation is ±0.05Hz, the start time is no more than 3s, the response time is no more than 10s, the adjustment time is no more than 15s, and the adjustment power error is ±2%P n .

4. A test method for testing a primary frequency modulation function according to claim 3, characterized in that: The response time of the wind farm is 10s, and the response time of the photovoltaic power station is 5s.

5. A test method for testing a primary frequency modulation function according to claim 1, characterized in that: The horizontal axis of the grid area is divided according to △P, and the calculation formula of △P is: In the formula, △p is the active power regulation; f is the test frequency; f d It is the primary frequency modulation dead zone; f n is the system rated frequency; P n It is the rated power of the new energy station; δ % is the primary frequency regulation coefficient of the new energy station.

6. A test method for testing a primary frequency modulation function according to claim 5, characterized in that: The horizontal axis curves of the grid area are 10%△P, horizontal axis I, 90%△P, 100%△P, and horizontal axis II; Horizontal axis I = P0 + △P + 0.02*P n ; Horizontal axis II = P0 + △P - 0.02*P n .

7. A test method for testing a primary frequency modulation function according to claim 6, characterized in that: Output test power curve P in the same coordinate 测试 And the grid determination Pt curve P in the corresponding time 判断 The criteria are as follows: If the test power curve P 测试 If the intersection point with the 10%△P horizontal axis curve is on the left side of the 3s vertical axis curve, the start-up time is qualified, otherwise it is unqualified; If the test power curve P 测试 If the intersection point with the 90%△P horizontal axis curve is on the left side of the 10s vertical axis curve, the response time is qualified, otherwise it is unqualified; If the test power curve P 测试 If all are within the area between horizontal axis Ⅰ and horizontal axis Ⅱ, the adjustment time and adjustment error are qualified, otherwise they are unqualified.

8. A test method for testing a primary frequency modulation function according to claim 1, characterized in that: Test power curve P 测试 It is the power curve when the frequency f exceeds the primary frequency modulation dead time.

9. A test method for testing a primary frequency modulation function according to claim 1, characterized in that: In step 1, the first active power data corresponding to the frequency f ≥ 50.05 or f ≤ 49.95 in the test data is set as the initial power P0.

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