Dynamic Reactive Power Compensation Device Response Time Detection Method and System

Abstract

The present invention provides a method and system for detecting the response time of a dynamic reactive power compensation device, belonging to the technical field of dynamic reactive power compensation. Synchronous measurement can be carried out under the condition that both the dynamic reactive power compensation device and the compensation object are operating normally; it does not affect the normal operation of the system, and can better reflect the compensation and response of the dynamic reactive power compensation device in the actual power grid; the response time of the compensation device is tested and analyzed by using the reactive power disturbance of the compensation object, without adding an additional disturbance source; it has the characteristics of improving the detection efficiency and accuracy, is easy to implement, and is more suitable for large-scale popularization and use.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic reactive power compensation, and specifically, to a method and system for detecting the response time of a dynamic reactive power compensation device. Background Art

[0002] With the extensive application of high-power impact load equipment such as AC / DC arc furnaces, continuous rolling mills, port cranes, fusion power sources, and urban rail transit loads, as well as the large-scale grid connection of large-capacity intermittent power generation stations such as wind power generation and photovoltaic power generation, the application demand for dynamic reactive power compensation devices has become prominent. The response time of a dynamic reactive power compensation device refers to the time from the input of a control signal (reference voltage) until the compensation device first reaches 90% of the target value, that is, the time from the change in reactive power load to the full input of all required compensation circuits. Generally, it is required that the response time of the dynamic reactive power compensation device is less than 20 milliseconds. If the compensation response is too slow, problems such as under-compensation, over-compensation, and voltage drop may occur due to the failure to timely input or cut off the required capacity. Therefore, the response time of the reactive power compensation device is an important indicator of the device's dynamic compensation performance.

[0003] In the prior art, for the test of the response time of a reactive power compensation device, under test conditions, a large reactive voltage step is generated by a disturbance source to obtain an accurate response time. However, the following drawbacks exist:

[0004] 1) In actual application scenarios, factors such as communication delay between devices, adjustment of control parameters, and changes in reactive power compensation requirements will all affect the response time of the reactive power compensation device, resulting in significant differences in the response time test results in different application scenarios.

[0005] 2) Some application scenarios often do not have the conditions to generate a large reactive voltage step, and it is also difficult to accurately capture the input moment of the control signal, posing a great challenge to the on-site measurement of the response time.

[0006] Therefore, there is an urgent need for a method to realize the on-line test and analysis of the response time of a dynamic reactive power compensation device by using the on-site operating conditions and conditions. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for detecting the response time of a dynamic reactive power compensation device with high efficiency, and by synchronously measuring under the condition that both the dynamic reactive power compensation device and the compensation object are operating normally, the effect of obtaining accurate and effective response time can be achieved.

[0008] To achieve the above purpose, a method for detecting the response time of a dynamic reactive power compensation device according to the present invention includes:

[0009] S110. Synchronously sample the current signal of the compensation object, the current signal of the dynamic compensation branch, and the voltage signal of the power supply bus according to the set period specification, and respectively obtain the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the voltage of the power supply bus;

[0010] S120. Use the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the voltage of the power supply bus to determine the instantaneous reactive power of the compensation object and the instantaneous reactive power of the dynamic compensation branch, and then obtain the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period;

[0011] S130. According to the cross-correlation function, determine the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; and,

[0012] When the linear correlation coefficient between the instantaneous reactive power sequence of the compensation object and the instantaneous reactive power sequence of the dynamic compensation branch is -1, obtain the corresponding lag order;

[0013] S140. Obtain the response time of the dynamic reactive power compensation device according to the lag order.

[0014] Furthermore, preferably, the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period is obtained through the following formula:

[0015]

[0016] Where, q 1 (k) represents the time series of the instantaneous reactive power of the compensation object within the sampling period; q 2 (k) represents the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; p represents the lag order of q 2 (k), and when p is a positive value, it means lagging p sampling points, when p is a negative value, it means leading p sampling points, p = 0, ±1, ……, ±p max ; p max is the selected maximum lag order; R[q 1 , q 2 , p] represents the correlation coefficient between q 1 (k) and q 2 (k + p), Cov[q 1 (k), q 2 (k + p)] is the covariance between q 1 (k) and q 2The covariance of (k + p), Var[q 1 (k)] and Var[q 2 (k + p)] are the variances of q 1 (k) and q 2 (k + p) respectively;

[0017] The set cycle specification includes a sampling cycle of M power frequency cycles, and the number of sampling points per cycle wave is N; k is the sampling point number, k = 1, 2, 3, ……, MN.

[0018] Furthermore, preferably, the response time of the dynamic reactive power compensation device is obtained according to the lag order through the following formula:

[0019]

[0020] where N is the number of sampling points per cycle wave, p is the lag order, f s is the power grid frequency; T s is the response time of the dynamic compensation device, with the unit of ms. The above power grid frequency is 50 Hz.

[0021] Furthermore, preferably, the time series of the instantaneous reactive power of the compensation object within the sampling cycle and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling cycle are obtained through the following formula:

[0022]

[0023] where i 1 (k) is the time-domain discrete value of the current of the compensation object; i 2 (k) is the time-domain discrete value of the current of the dynamic compensation branch; u(k) is the time-domain discrete value of the supply bus voltage;

[0024] and i 1 (k) = [i a1 (k) i b1 (k) i c1 (k)], i 2 (k) = [i a2 (k) i b2 (k) i c2 (k)], u(k) = [u a (k) u b (k) u c (k)];

[0025] a, b, and c respectively represent the A phase, B phase, and C phase of the three-phase alternating current.

[0026] Furthermore, preferably, N ≥ 16; the sampling cycle covers at least 1 complete dynamic compensation process.

[0027] The present invention also protects a dynamic reactive power compensation device response time detection system, including

[0028] a sampling unit, configured to synchronously sample the current signal of the compensation object, the current signal of the dynamic compensation branch, and the power supply bus voltage signal according to a set period specification, and respectively obtain the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the power supply bus voltage;

[0029] a time series acquisition unit, configured to use the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the power supply bus voltage to determine the instantaneous reactive power of the compensation object and the instantaneous reactive power of the dynamic compensation branch, and further obtain the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period;

[0030] an order acquisition unit, configured to determine the linear cross-correlation coefficient of the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period according to the cross-correlation function; and,

[0031] when the linear correlation coefficient between the instantaneous reactive power sequence of the compensation object and the instantaneous reactive power sequence of the dynamic compensation branch is -1, obtain the corresponding order;

[0032] a response time acquisition unit, configured to obtain the response time of the dynamic reactive power compensation device according to the lag order.

[0033] Furthermore, preferably, the linear cross-correlation coefficient of the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period is obtained through the following formula:

[0034]

[0035] wherein, q 1 (k) represents the time series of the instantaneous reactive power of the compensation object within the sampling period; q 2 (k) represents the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; p represents the lag order of q 2 (k), and when p is a positive value, it represents lagging p sampling points, when p is a negative value, it represents leading p sampling points, p = 0, ±1, ……, ±p max ; p max is the selected maximum lag order; R[q 1 , q 2 , p] represents the correlation coefficient between q 1 (k) and q 2 (k + p), Cov[q1 (k), q 2 (k + p) is q 1 (k) and q 2 Covariance of (k + p), Var[q 1 Var[(k)] and Var[q 2 (k + p) are respectively q 1 (k) and q 2 Variances of (k + p);

[0036] The set cycle specification includes a sampling period of M power frequency cycles, and the number of sampling points per cycle wave is N; k is the sampling point number, k = 1, 2, 3,..., MN.

[0037] As described above, a method and system for detecting the response time of a dynamic reactive power compensation device according to the present invention have the following beneficial effects:

[0038] 1), Synchronous measurement can be carried out under the condition that both the dynamic reactive power compensation device and the compensation object are operating normally; it does not affect the normal operation of the system, and can better reflect the compensation and response of the dynamic reactive power compensation device in the actual power grid.

[0039] 2), Utilize the reactive power disturbance of the compensation object to realize the test and analysis of the response time of the compensation device, without the need to add an additional disturbance source.

[0040] 3) It has the characteristics of improving the detection efficiency and accuracy, is easy to implement, and is more suitable for large-scale promotion and use.

[0041] To achieve the above and related purposes, one or more aspects of the present invention include features that will be described in detail later and specifically pointed out in the claims. The following description and the accompanying drawings detail certain exemplary aspects of the present invention. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] By referring to the following description in conjunction with the accompanying drawings and the content of the claims, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easier to understand. In the drawings:

[0043] Figure 1 Is a schematic diagram of the setting position of the time-domain discrete signal test points of the method for detecting the response time of a dynamic reactive power compensation device according to an embodiment of the present invention.

[0044] Figure 2 Is a comparison diagram of the three-phase instantaneous reactive power sequences of a DC arc furnace and a dynamic compensation branch in the method for detecting the response time of a dynamic reactive power compensation device according to an embodiment of the present invention;

[0045] Figure 3 It is the cross - correlation coefficient distribution diagram corresponding to different lag orders in the method for detecting the response time of the static var compensation device according to the embodiments of the present invention;

[0046] Figure 4 It is the logical schematic diagram of the dynamic var compensation device response time detection system according to the embodiments of the present invention. Detailed implementation manners

[0047] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is obvious that these embodiments can also be implemented without these specific details. In other instances, well - known structures and devices are shown in block diagram form for the convenience of describing one or more embodiments.

[0048] In the prior art, an electronic load generates a reactive power step that conforms to the response time, the reactive power compensation starts to operate in the automatic compensation mode, and at the same time, the three - phase current waveforms of the load and the compensation current waveforms output by the reactive power compensation device are tested. From the moment when the reactive power load of the electronic load starts to mutate to a preset ratio of the target value reached by the output of the reactive power compensation device, the dynamic response time is obtained.

[0049] To solve the problems that the existing method for measuring the response time of a dynamic var compensation device has strict requirements for test conditions and cannot accurately reflect the actual operation of the dynamic var compensation device, the method for detecting the response time of the dynamic var compensation device provided by the present invention can perform synchronous measurement under the condition that both the dynamic var compensation device and the compensation object are operating normally; utilize the reactive power disturbance of the compensation object to realize the test and analysis of the response time of the compensation device, without adding an additional disturbance source, without affecting the normal operation of the system, and the measured response time of the dynamic var compensation device can better reflect the compensation and response of the dynamic var compensation device in the actual power grid.

[0050] The following will describe each embodiment of the present invention in detail with reference to the accompanying drawings.

[0051] To achieve the above - mentioned purpose, a method for detecting the response time of a dynamic var compensation device of the present invention includes steps S110 - S140.

[0052] S110. Synchronously sample the current signal of the compensation object, the current signal of the dynamic compensation branch, and the voltage signal of the power supply bus according to the set period specifications, and respectively obtain the time - domain discrete values of the current of the compensation object, the time - domain discrete values of the current of the dynamic compensation branch, and the time - domain discrete values of the voltage of the power supply bus.

[0053] Figure 1 The setting positions of the time - domain discrete signal test points of the method for detecting the response time of the dynamic var compensation device are described as a whole. Specifically,Figure 1 Schematic diagram of the setting positions of the time-domain discrete signal test points for the method of detecting the response time of a dynamic reactive power compensation device according to an embodiment of the present invention; as Figure 1 shown, a power supply bus voltage signal test point is set on the power supply bus, a compensated object current signal test point is set on the branch of the compensated object, a dynamic compensation branch current signal test point is set on the dynamic compensation branch, and synchronous sampling is performed at each test point, that is, the compensated object current signal i 1 (t), the dynamic compensation branch current signal i 2 (t) and the power supply bus voltage signal u(t) are synchronously sampled. It should be noted that the set period specifications include a sampling period of M power frequency cycles, and the number of sampling points per cycle wave is N; k is the sampling point number, k = 1, 2, 3,..., MN.

[0054] Specifically, i 1 (k) is the time-domain discrete value of the compensated object current; i 2 (k) is the time-domain discrete value of the dynamic compensation branch current; u(k) is the time-domain discrete value of the power supply bus voltage; and i 1 (k) = [i a1 (k) i b1 (k) i c1 (k)], i 2 (k) = [i a2 (k) i b2 (k) i c2 (k)], u(k) = [u a (k) u b (k) u c (k)];

[0055] wherein, a, b, and c respectively represent the A-phase, B-phase, and C-phase of three-phase alternating current.

[0056] In the specific implementation process, in order to further improve the detection accuracy of the response time of the dynamic reactive power compensation device, it is required that N ≥ 16, that is, the sampling rate of the discrete signal ≥ 800 Hz. The sampling period covers at least 1 complete dynamic compensation process.

[0057] S120. Using the time-domain discrete value of the compensated object current, the time-domain discrete value of the dynamic compensation branch current, and the time-domain discrete value of the power supply bus voltage, determine the instantaneous reactive power of the compensated object and the instantaneous reactive power of the dynamic compensation branch, and then obtain the time series of the instantaneous reactive power of the compensated object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period.

[0058] The time series of the instantaneous reactive power of the object to be compensated within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period are obtained through the following formula:

[0059]

[0060] where q 1 (k) represents the time series of the instantaneous reactive power of the object to be compensated within the sampling period; q 2 (k) represents the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period.

[0061] S130. Determine the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the object to be compensated within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period according to the cross-correlation function; and, when the linear correlation coefficient between the instantaneous reactive power sequence of the object to be compensated and the instantaneous reactive power sequence of the dynamic compensation branch is -1, obtain the corresponding lag order.

[0062] The linear cross-correlation coefficient between the time series of the instantaneous reactive power of the object to be compensated within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period is obtained through the following formula:

[0063]

[0064] where q 1 (k) represents the time series of the instantaneous reactive power of the object to be compensated within the sampling period; q 2 (k) represents the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; p represents the lag order of q 2 (k), and when p is positive, it means lagging p sampling points, when p is negative, it means leading p sampling points, p = 0, ±1,..., ±p max ; p max is the selected maximum lag order; R[q 1 , q 2 , p] represents the correlation coefficient between q 1 (k) and q 2 (k + p), Cov[q 1 (k), q 2 (k + p)] is the covariance between q 1 (k) and q 2 (k + p), and Var[q 1 (k)] and Var[q 2 (k + p)] are the variances of q 1 (k) and q 2 (k + p) respectively.

[0065] It should be noted that the linear cross-correlation coefficient R[q 1 ,q 2 ,p] ranges from [1, -1]. When the value of the linear cross-correlation coefficient R[q 1 ,q 2 ,p] is -1, it indicates a linear negative correlation. When the value of the linear cross-correlation coefficient R[q 1 ,q 2 ,p] is +1, it indicates a linear positive correlation. The closer the value of the linear cross-correlation coefficient R[q 1 ,q 2 ,p] is to 0, the weaker the linear correlation.

[0066] Since the reactive power characteristics of the dynamic compensation branch and the compensation object are exactly opposite, when R[q 1 ,q 2 ,p] takes the lag order p corresponding to the maximum negative correlation (i.e., -1), it is the number of points by which the reactive power output of the dynamic compensation device lags behind the compensation object.

[0067] S140. Obtain the response time of the dynamic reactive power compensation device according to the lag order. That is, convert the lag order p into the corresponding time to obtain the response time of the dynamic reactive power compensation device.

[0068] The response time of the dynamic reactive power compensation device is obtained according to the lag order through the following formula:

[0069]

[0070] where N is the number of sampling points per cycle, p is the lag order, f s is the grid frequency; T s is the response time of the dynamic compensation device, with the unit of ms. The above grid frequency is 50 Hz.

[0071] The following is illustrated through a specific embodiment.

[0072] Embodiment 1

[0073] Taking the test of the DC arc furnace power distribution system as an example, the time-domain discrete signals of the 35 kV supply bus voltage of the DC arc furnace, the feeder current of the DC arc furnace, and the current of the dynamic compensation branch are obtained. Among them, the number of sampling points per cycle is N = 64, and the sampling period is M = 12. Then the data lengths of the time-domain discrete signals of the feeder current of the DC arc furnace, the current of the dynamic compensation branch, and the supply bus voltage are 768. The instantaneous reactive power trends of the DC arc furnace and the SVC dynamic compensation branch calculated according to formulas (1) and (2) are respectively as Figure 2 shown.

[0074] For the time series q of the instantaneous reactive power of the compensation object within the sampling period1 (k) and the time series q of the instantaneous reactive power of the dynamic compensation branch within the sampling period 2 (k) calculates the linear cross-correlation coefficient. Among them, the maximum lag order p max = 80, and the distribution of the obtained linear cross-correlation coefficient is as Figure 3 shown. It can be seen that the lag order p corresponding to the maximum negative correlation is 42. Then, substituting it into Equation (4) to obtain the response time of the dynamic reactive power compensation device 13.1 ms < 20 ms; therefore, for the DC arc furnace power distribution system of Embodiment 1, the response time of its dynamic reactive power compensation device meets the standard.

[0075] In summary, synchronous measurement can be carried out under the condition that both the dynamic reactive power compensation device and the compensation object are operating normally; the test and analysis of the response time of the compensation device are realized by using the reactive power disturbance of the compensation object, without adding additional disturbance sources, without affecting the normal operation of the system, and the measured response time of the dynamic reactive power compensation device can better reflect the compensation and response of the dynamic reactive power compensation device in the actual power grid.

[0076] Figure 4 The response time detection system of the dynamic reactive power compensation device is described as a whole. Specifically, Figure 4 is a logical schematic diagram of the response time detection system 400 of the dynamic reactive power compensation device according to an embodiment of the present invention; as Figure 4 shown,

[0077] The sampling unit 410 is used to synchronously sample the current signal of the compensation object, the current signal of the dynamic compensation branch, and the voltage signal of the power supply bus according to the set period specifications, and respectively obtain the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the voltage of the power supply bus;

[0078] The time series acquisition unit 420 is used to use the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the voltage of the power supply bus to determine the instantaneous reactive power of the compensation object and the instantaneous reactive power of the dynamic compensation branch, and further obtain the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period;

[0079] The order acquisition unit 430 is used to determine the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period according to the cross-correlation function; and,

[0080] when the linear correlation coefficient between the instantaneous reactive power sequence of the compensation object and the instantaneous reactive power sequence of the dynamic compensation branch is -1, obtain the corresponding order;

[0081] A response time acquisition unit 440, configured to obtain the response time of the dynamic reactive power compensation device according to the lag order.

[0082] In a specific embodiment, the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period is obtained through the following formula:

[0083]

[0084] where q 1 (k) represents the time series of the instantaneous reactive power of the compensation object within the sampling period; q 2 (k) represents the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; p represents the lag order of q 2 (k), and when p is a positive value, it means lagging p sampling points, when p is a negative value, it means leading p sampling points, p = 0, ±1, ……, ±p max ; p max is the selected maximum lag order; R[q 1 , q 2 , p] represents the correlation coefficient between q 1 (k) and q 2 (k + p), Cov[q 1 (k), q 2 (k + p)] is the covariance between q 1 (k) and q 2 (k + p), Var[q 1 (k)] and Var[q 2 (k + p)] are the variances of q 1 (k) and q 2 (k + p) respectively;

[0085] The set period specification includes that the sampling period is M power frequency cycles, and the number of sampling points per cycle wave is N; k is the sampling point number, k = 1, 2, 3, ……, MN.

[0086] For other implementation details, refer to the implementation manner of the dynamic reactive power compensation device response time detection method, which will not be elaborated here.

[0087] In summary, the present invention relates to a method and system for detecting the response time of a dynamic reactive power compensation device, which can perform synchronous measurement under the condition that both the dynamic reactive power compensation device and the compensation object are operating normally; it does not affect the normal operation of the system and can better reflect the compensation and response of the dynamic reactive power compensation device in the actual power grid; it uses the reactive power disturbance of the compensation object to realize the test and analysis of the response time of the compensation device without adding an additional disturbance source; it has the characteristics of improving the detection efficiency and accuracy, is easy to implement, and is more suitable for large-scale popularization and use.

[0088] However, those skilled in the art should understand that various improvements can be made to the above-mentioned method and system for detecting the response time of the dynamic reactive power compensation device provided by the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the appended claims.

Claims

1. A method for detecting the response time of a dynamic reactive power compensation device, characterized in that, the method includes: S110. Synchronously sample the current signal of the compensation object, the current signal of the dynamic compensation branch, and the voltage signal of the power supply bus according to the set period specification, and respectively obtain the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the voltage of the power supply bus; S120. Use the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the voltage of the power supply bus to determine the instantaneous reactive power of the compensation object and the instantaneous reactive power of the dynamic compensation branch, and then obtain the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; S130. According to the cross-correlation function, determine the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; and, when the linear correlation coefficient between the instantaneous reactive power sequence of the compensation object and the instantaneous reactive power sequence of the dynamic compensation branch is -1, obtain the corresponding lag order; S140. Obtain the response time of the dynamic reactive power compensation device according to the lag order.

2. The method for detecting the response time of a dynamic reactive power compensation device according to claim 1, characterized in that, the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period is obtained by the following formula: Among them, q 1 (k) represents the time series of the instantaneous reactive power of the object to be compensated within the sampling period; q 2 (k) represents the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; p represents the lag order of q 2 (k), and when p is a positive value, it means lagging p sampling points, and when p is a negative value, it means leading p sampling points, p = 0, ±1, ……, ±p max ; p max is the maximum lag order selected; R[q 1 , q 2 , p] represents the correlation coefficient between q 1 (k) and q 2 (k + p), Cov[q 1 (k), q 2 (k + p)] is the covariance between q 1 (k) and q 2 (k + p), Var[q 1 (k)] and Var[q 2 (k + p)] are the variances of q 1 (k) and q 2 (k + p) respectively; The set period specification includes that the sampling period is M power frequency cycles, and the number of sampling points per cycle wave is N; k is the sampling point number, k = 1, 2, 3,..., MN.

3. The method for detecting the response time of a dynamic reactive power compensation device according to claim 1, characterized in that, The response time of the dynamic reactive power compensation device is obtained according to the lag order through the following formula: where N is the number of points sampled per cycle of the wave, p is the lag order, and f s is the grid frequency; T s is the response time of the dynamic compensation device, with the unit of ms; the above grid frequency is 50 Hz.

4. The method for detecting the response time of a dynamic reactive power compensation device according to claim 2, characterized in that, the time series of the instantaneous reactive power of the compensation object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period are obtained by the following formula: wherein, i 1 (k) is the time-domain discrete value of the compensated object current; i 2 (k) is the time-domain discrete value of the dynamic compensation branch current; u(k) is the time-domain discrete value of the power supply bus voltage; and i 1 (k)=[i a1 (k) i b1 (k) i c1 (k)], i 2 (k)=[i a2 (k) i b2 (k) i c2 (k)], u(k)=[u a (k) u b (k) u c (k)]; a, b, and c respectively represent the A phase, B phase, and C phase of three-phase alternating current.

5. The method for detecting the response time of a dynamic reactive power compensation device according to claim 2, characterized in that, N≥16; the sampling period covers at least one complete dynamic compensation process.

6. A system for detecting the response time of a dynamic reactive power compensation device, characterized in that, including a sampling unit, configured to synchronously sample the current signal of the compensation object, the current signal of the dynamic compensation branch, and the voltage signal of the power supply bus according to the set period specification, and respectively obtain the time-domain discrete values of the current of the compensation object, the time-domain discrete values of the current of the dynamic compensation branch, and the time-domain discrete values of the voltage of the power supply bus; A time series acquisition unit, configured to use the time-domain discrete values of the compensated object current, the time-domain discrete values of the dynamic compensation branch current, and the time-domain discrete values of the power supply bus voltage to determine the instantaneous reactive power of the compensated object and the instantaneous reactive power of the dynamic compensation branch, and further obtain the time series of the instantaneous reactive power of the compensated object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; An order acquisition unit, configured to determine the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensated object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period according to the cross-correlation function; And, when the linear correlation coefficient between the instantaneous reactive power sequence of the compensated object and the instantaneous reactive power sequence of the dynamic compensation branch is -1, obtain the corresponding lag order; A response time acquisition unit, configured to obtain the response time of the dynamic reactive power compensation device according to the lag order.

7. The dynamic reactive power compensation device response time detection system according to claim 6, wherein, the linear cross-correlation coefficient between the time series of the instantaneous reactive power of the compensated object within the sampling period and the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period is obtained through the following formula: Among them, q 1 (k) represents the time series of the instantaneous reactive power of the object to be compensated within the sampling period; q 2 (k) represents the time series of the instantaneous reactive power of the dynamic compensation branch within the sampling period; p represents the lag order of q 2 (k), and when p is a positive value, it means lagging p sampling points, and when p is a negative value, it means leading p sampling points, p = 0, ±1, ……, ±p max ; p max is the maximum lag order selected; R[q 1 , q 2 , p] represents the correlation coefficient between q 1 (k) and q 2 (k + p), Cov[q 1 (k), q 2 (k + p)] is the covariance between q 1 (k) and q 2 (k + p), Var[q 1 (k)] and Var[q 2 (k + p)] are the variances of q 1 (k) and q 2 (k + p) respectively; The set period specification includes that the sampling period is M power frequency cycles, and the number of sampling points per cycle is N; k is the sampling point number, k = 1, 2, 3,..., MN.

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