CN104967133A - A Gain Adaptive Control Method of SVC Voltage Regulator Based on Closed-loop Integration - Google Patents

Abstract

The invention relates to a closed-loop integration-based SVC voltage regulator gain adaptive control method, comprising the following steps: (1) performing oscillation detection on the susceptance per unit value Bpu signal output by the voltage regulator, when the voltage regulation is detected Perform fast gain adjustment when the output of the voltage regulator is oscillating; (2) If the susceptance per unit value Bpu signal oscillation of the voltage regulator output disappears and lasts for 30s, the susceptance per unit value Bpu signal output by the voltage regulator is performed Gain optimization; the present invention relates to a closed-loop integration-based SVC voltage regulator gain adaptive control method without intervening in the normal adjustment of the SVC, without the estimation of short-circuit capacity, and adopting the method of closed-loop integration to realize the optimization of the gain, according to the oscillation Detect and stabilize the monitoring results, monitor whether the gain amount is reasonable and optimize the gain amount in real time.

Description

A Gain Adaptive Control Method of SVC Voltage Regulator Based on Closed-loop Integration

technical field

The invention relates to a gain adaptive control method of an SVC voltage regulator, in particular to a closed-loop integration-based gain adaptive control method of an SVC voltage regulator.

Background technique

With the expansion of the power grid scale and the increasingly complex operating environment in China, in order to improve the safety, stability and economic operation level of the power grid in the transformation of the backbone power grid and the construction of the UHV power grid, the receiving end system should have sufficient reactive power reserves, especially When the receiving end system has voltage stability problems, it is necessary to configure dynamic reactive power compensation equipment in the hub substation of the receiving end system.

Static var compensation (SVC) voltage regulators have the functions of improving voltage control, improving static and transient stability of the system, increasing power transmission capacity, damping system oscillation, and reducing power frequency overvoltage in high-voltage transmission systems. SVC voltage regulators have important significance and broad application prospects in domestic and foreign power transmission systems. The voltage regulator gain KG is closely related to any event that changes the short-circuit level of the SVC bus, such as the grid structure, system operation mode, and switching lines. If the gain of the voltage regulator is unreasonable, the SVC response time will increase significantly, and the control loop may oscillate or even become unstable.

At present, the method adopted when designing the gain control of the SVC voltage regulator in the transmission system is: inject a small reactive power step through the SVC, measure the reactive power change value and the voltage change value, and measure the value of the reactive power change value and the voltage change value from the common connection point voltage change and the SVC reactive power output Change to estimate the short-circuit capacity of the common connection point, and then estimate the gain of the voltage regulator based on the calculated short-circuit capacity. This method needs to measure the short-circuit capacity by intervening in the normal reactive power output of the SVC. If there are multiple SVCs in a close electrical area, the voltage control among the SVCs will affect each other. In order to accurately measure the short-circuit capacity, it is necessary to establish a communication connection between the SVCs to coordinate the gain control of the SVCs.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a closed-loop integration-based SVC voltage regulator gain adaptive control method, which does not need to intervene in the normal adjustment of the SVC, does not need to estimate the short-circuit capacity, and adopts the method of closed-loop integration to realize the gain According to the results of oscillation detection and stability monitoring, monitor whether the gain amount is reasonable and optimize the gain amount in real time.

The object of the present invention is to adopt following technical scheme to realize:

A closed-loop integration-based gain adaptive control method for SVC voltage regulators, the improvement of which includes:

(1) Oscillation detection is carried out to the susceptance per unit value Bpu signal output by the voltage regulator, and when it is detected that the output of the voltage regulator has oscillation, the gain is quickly adjusted;

(2) If the oscillation of the susceptance per unit Bpu signal output by the voltage regulator disappears and lasts for 30s, perform gain optimization on the susceptance per unit Bpu signal output by the voltage regulator.

Preferably, said step (1) includes:

(1-1) filter the susceptance per unit value Bpu output by the voltage regulator through a bandpass filter to obtain a signal osc0 that can reflect oscillation; wherein, the frequency of the signal osc0 that can reflect oscillation is 5 -60Hz;

(1-2) Set the first threshold value and compare it with the osc0 to determine whether there is oscillation in the osc0, and if there is oscillation, the acquisition width is the time corresponding to the amplitude of the osc0 exceeding the first threshold value The first pulse signal and go to step (1-3), if there is no oscillation then end the operation;

(1-3) Integrate the time between two adjacent zero-crossing points in the osc0 and obtain the frequency value of the integration result, if the frequency value of the integration result is greater than 10Hz then go to step (1-4 ), if the frequency value is less than 10Hz, then end the operation;

(1-4) integrating the pulse signal between two adjacent zero-crossing points in the first pulse signal, and multiplying the integral result by a proportional coefficient, thereby obtaining the first gain adjustment amount;

(1-5) Adjusting the gain amount of the SVC voltage regulator, and updating the gain amount, that is, subtracting the first gain adjustment amount from the gain amount of the SVC voltage regulator;

(1-6) If the updated gain amount is within the gain limit value range, the gain amount of the SVC voltage regulator is taken as the updated gain amount; if the updated gain amount is greater than the maximum gain limit value value, the gain value of the SVC voltage regulator takes the maximum value of the gain limit value; if the updated gain value is less than the minimum value of the gain limit value, then the gain value of the SVC voltage regulator takes the minimum value of the gain limit value value.

Further, the step (1-2), judging whether there is oscillation in the osc0 includes: setting a first threshold value and comparing it with the osc0, if the amplitude of the osc0 is higher than the first threshold within 150 ms value, there is oscillation in the osc0, and if the amplitude of the osc0 is lower than the first threshold and lasts for 150 ms, there is no oscillation in the osc0.

Preferably, said step (2) includes:

(2-1) Set the second threshold value and compare it with the osc0. If the osc0 oscillation disappears and lasts for 30s, then judge whether the osc0 is stable. If the osc0 is stable, slowly increase the SVC voltage adjustment according to the step size The gain amount of the device reaches the maximum value of the gain limit value, if the osc0 is unstable, then obtain the second pulse signal whose width is the time corresponding to the osc0 amplitude value exceeding the second threshold value and go to step (2- 2); wherein, the second threshold value is much smaller than the first threshold value;

(2-2) Integrate the time between two adjacent zero-crossing points in the osc0 and obtain the frequency value of the integration result, if the frequency value of the integration result is greater than 10Hz then go to step (2-3 ), if the frequency value is less than 10Hz, then end the operation;

(2-3) Integrating the pulse signal between two adjacent zero-crossing points in the second pulse signal, and multiplying the integral result by a proportional coefficient, thereby obtaining a second gain adjustment amount;

(2-4) Adjusting the gain amount of the SVC voltage regulator, and updating the gain amount, that is, subtracting the second gain adjustment amount from the gain amount of the SVC voltage regulator;

(2-5) If the updated gain amount is within the gain limit value range, the gain amount of the SVC voltage regulator is taken as the updated gain amount; if the updated gain amount is greater than the maximum gain limit value value, the gain value of the SVC voltage regulator takes the maximum value of the gain limit value; if the updated gain value is less than the minimum value of the gain limit value, then the gain value of the SVC voltage regulator takes the minimum value of the gain limit value value.

Further, the step (2-1), judging whether the osc0 is stable includes: setting a second threshold value for comparison with the osc0, if the amplitude of the osc0 is higher than the second threshold value, then the The osc0 is unstable, and if the amplitude of the osc0 is lower than the second threshold within 150 ms, the osc0 is stable.

Further, the gain limit value can be set according to the capacity adjustment range of the SVC voltage regulator and the short-circuit capacity of the common connection point where the SVC voltage regulator is connected to the system.

Beneficial effects of the present invention:

(1) There is no need to intervene in the normal adjustment of the SVC, and it is not necessary to estimate the short-circuit capacity, and the closed-loop integration method is adopted to realize the optimization of the gain.

(2) When applied to multiple sets of SVCs in the power transmission system, communication between the SVC controls is not required, and it can be flexibly and conveniently applied to the gain control of multiple sets of SVCs.

(3) It can effectively monitor the oscillation of the SVC voltage regulator, and quickly reduce the gain, effectively suppress the control oscillation, and restore the stability of the system.

(4) It can adaptively track the change of the short-circuit capacity of the system, automatically optimize the gain to a value suitable for the current short-circuit level, and ensure that the system is stable and the SVC has good dynamic response characteristics.

Description of drawings

Fig. 1 is the method flow chart of a kind of SVC voltage regulator gain self-adaptive control method based on closed-loop integral of the present invention;

Fig. 2 is a program diagram of step (1) in Fig. 1;;

Fig. 3 is a kind of closed-loop integration-based SVC voltage regulator gain self-adaptive control method of the present invention suppresses the result schematic diagram of oscillation;

Fig. 4 is the program diagram of step (2) among Fig. 1;

Fig. 5 is a diagram showing the change of the gain value after the oscillation disappears in step (2).

Detailed ways

The specific implementation manners of the present invention will be described in detail below in conjunction with the accompanying drawings.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The gain adaptive control method based on closed-loop integral control proposed by the present invention is applied to the gain control of the SVC voltage regulator of the power transmission system, continuously monitors the output of the voltage regulator, and detects whether there is any continuous amplitude oscillation. Gain oscillations occur while the regulator is still running at high gain. If an increasing oscillation of the voltage regulator output is detected, the gain is continuously reduced until the oscillation disappears. This can not only protect the control loop and power system, but also avoid the unstable output of the controller caused by the change of short-circuit capacity of the grid, system disturbance or unreasonable adjustment parameters. It has the advantages of easy implementation, effective suppression of oscillation and optimization of dynamic response characteristics. sex.

A closed-loop integration-based gain adaptive control method for SVC voltage regulators, as shown in Figure 1, includes:

(1) Oscillation detection is carried out to the susceptance per unit value Bpu signal output by the voltage regulator, and when it is detected that the output of the voltage regulator has oscillation, the gain is quickly adjusted;

(2) If the oscillation of the susceptance per unit Bpu signal output by the voltage regulator disappears and lasts for 30s, perform gain optimization on the susceptance per unit Bpu signal output by the voltage regulator.

Wherein, described step (1), as shown in Figure 2, comprises:

(1-1) filter the susceptance per unit value Bpu output by the voltage regulator through a bandpass filter to obtain a signal osc0 that can reflect oscillation; wherein, the frequency of the signal osc0 that can reflect oscillation is 5 -60Hz;

(1-2) Set the first threshold value and compare it with the osc0 to determine whether there is oscillation in the osc0, and if there is oscillation, the acquisition width is the time corresponding to the amplitude of the osc0 exceeding the first threshold value The first pulse signal and go to step (1-3), and end the operation if there is no oscillation; wherein, the first threshold value can reflect the sensitivity of oscillation detection.

Specifically, the step (1-2), judging whether there is oscillation in the osc0 includes: setting a first threshold value and comparing it with the osc0, if the amplitude of the osc0 is higher than the first threshold within 150 ms value, there is oscillation in the osc0, and if the amplitude of the osc0 is lower than the first threshold and lasts for 150 ms, there is no oscillation in the osc0.

(1-3) Integrate the time between two adjacent zero-crossing points in the osc0 and obtain the frequency value of the integration result, if the frequency value of the integration result is greater than 10Hz then go to step (1-4 ), if the frequency value is less than 10Hz, then end the operation;

In order to avoid affecting the damping effect of the SVC voltage regulator on the low-frequency oscillation of the system, the distinction between the power system oscillation and the voltage regulator oscillation can be achieved by measuring the output oscillation frequency of the voltage regulator. When the osc0 signal exists and the oscillation disappears, step (1-3 ) will be prohibited.

(1-4) integrating the pulse signal between two adjacent zero-crossing points in the first pulse signal, and multiplying the integral result by a proportional coefficient, thereby obtaining the first gain adjustment amount;

(1-5) Adjusting the gain amount of the SVC voltage regulator, and updating the gain amount, that is, subtracting the first gain adjustment amount from the gain amount of the SVC voltage regulator;

(1-6) If the updated gain amount is within the gain limit value range, the gain amount of the SVC voltage regulator is taken as the updated gain amount; if the updated gain amount is greater than the maximum gain limit value value, the gain value of the SVC voltage regulator takes the maximum value of the gain limit value; if the updated gain value is less than the minimum value of the gain limit value, then the gain value of the SVC voltage regulator takes the minimum value of the gain limit value value.

For example, as shown in Figure 3, when the short-circuit capacity of the system suddenly decreases, the original gain is too large to cause a certain degree of oscillation, the SVC voltage regulator will quickly reduce the gain after detecting the oscillation, and the oscillation is completely suppressed after about 400ms returned to a stable state again.

Described step (2), as shown in Figure 4, the principle of carrying out stable monitoring to described osc0 and optimizing gain amount is similar to the principle of carrying out oscillation detection to described osc0, but its threshold value is higher than the threshold value of oscillation detection Low, with higher sensitivity, including:

(2-1) Set the second threshold value and compare it with the osc0. If the osc0 oscillation disappears and lasts for 30s, then judge whether the osc0 is stable. If the osc0 is stable, slowly increase the SVC voltage adjustment according to the step size The gain amount of the device reaches the maximum value of the gain limit value, if the osc0 is unstable, then obtain the second pulse signal whose width is the time corresponding to the osc0 amplitude value exceeding the second threshold value and go to step (2- 2); wherein, the second threshold value is much smaller than the first threshold value;

Specifically, the step (2-1), judging whether the osc0 is stable includes: setting a second threshold value for comparison with the osc0, if the amplitude of the osc0 is higher than the second threshold value, the The osc0 is unstable, and if the amplitude of the osc0 is lower than the second threshold within 150 ms, the osc0 is stable.

(2-2) Integrate the time between two adjacent zero-crossing points in the osc0 and obtain the frequency value of the integration result, if the frequency value of the integration result is greater than 10Hz then go to step (2-3 ), if the frequency value is less than 10Hz, then end the operation;

(2-3) Integrating the pulse signal between two adjacent zero-crossing points in the second pulse signal, and multiplying the integral result by a proportional coefficient, thereby obtaining a second gain adjustment amount;

(2-4) Adjusting the gain amount of the SVC voltage regulator, and updating the gain amount, that is, subtracting the second gain adjustment amount from the gain amount of the SVC voltage regulator;

(2-5) If the updated gain amount is within the gain limit value range, the gain amount of the SVC voltage regulator is taken as the updated gain amount; if the updated gain amount is greater than the maximum gain limit value value, the gain value of the SVC voltage regulator takes the maximum value of the gain limit value; if the updated gain value is less than the minimum value of the gain limit value, then the gain value of the SVC voltage regulator takes the minimum value of the gain limit value value.

For example, as shown in Figure 5, after the oscillation disappears, the gain is optimized to a relatively small value, and the system voltage remains stable. As the short-circuit capacity gradually increases, the gain value is also continuously adjusted and increased.

Further, the gain limit value can be set according to the capacity adjustment range of the SVC voltage regulator and the short-circuit capacity of the common connection point where the SVC voltage regulator is connected to the system.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (6)

1. a kind of SVC voltage regulator gain adaptive control method based on closed-loop integration, it is characterized in that, may further comprise the steps: (1) Oscillation detection is carried out to the susceptance per unit value Bpu signal output by the voltage regulator, and when it is detected that the output of the voltage regulator has oscillation, the gain is quickly adjusted; (2) If the oscillation of the susceptance per unit Bpu signal output by the voltage regulator disappears and lasts for 30s, perform gain optimization on the susceptance per unit Bpu signal output by the voltage regulator. 2. method as claimed in claim 1, is characterized in that, described step (1) comprises: (1-1) filtering the susceptance per unit value Bpu output by the voltage regulator through a bandpass filter to obtain a signal osc0 that can reflect oscillation; (1-2) Set the first threshold value and compare it with the osc0 to determine whether there is oscillation in the osc0, and if there is oscillation, the acquisition width is the time corresponding to the amplitude of the osc0 exceeding the first threshold value The first pulse signal and go to step (1-3), if there is no oscillation then end the operation; (1-3) Integrate the time between two adjacent zero-crossing points in the osc0 and obtain the frequency value of the integration result, if the frequency value of the integration result is greater than 10Hz then go to step (1-4 ), if the frequency value is less than 10Hz, then end the operation; (1-4) integrating the pulse signal between two adjacent zero-crossing points in the first pulse signal, and multiplying the integral result by a proportional coefficient, thereby obtaining the first gain adjustment amount; (1-5) Adjusting the gain amount of the SVC voltage regulator, and updating the gain amount, that is, subtracting the first gain adjustment amount from the gain amount of the SVC voltage regulator; (1-6) If the updated gain amount is within the gain limit value range, the gain amount of the SVC voltage regulator is taken as the updated gain amount; if the updated gain amount is greater than the maximum gain limit value value, the gain value of the SVC voltage regulator takes the maximum value of the gain limit value; if the updated gain value is less than the minimum value of the gain limit value, then the gain value of the SVC voltage regulator takes the minimum value of the gain limit value value. 3. The method according to claim 2, wherein in the step (1-2), judging whether there is oscillation in the osc0 comprises: setting a first threshold value and comparing it with the osc0, if the osc0 If the amplitude of the osc0 is higher than the first threshold within 150ms, there is oscillation in the osc0, and if the amplitude of the osc0 is lower than the first threshold for 150ms, then there is no oscillation in the osc0. 4. method as claimed in claim 1, is characterized in that, described step (2) comprises: (2-1) Set the second threshold value and compare it with the signal osc0 that can reflect the oscillation. If the osc0 oscillation disappears and lasts for 30s, it is judged whether the osc0 is stable. If the osc0 is stable, slowly increase the osc0 according to the step size. The gain amount of the SVC voltage regulator reaches the maximum value of the gain limit value, if the osc0 is unstable, then obtain a second pulse signal whose width is the time corresponding to the osc0 amplitude exceeding the second threshold value and go to step (2-2); wherein, the second threshold value is much smaller than the first threshold value; (2-2) Integrate the time between two adjacent zero-crossing points in the osc0 and obtain the frequency value of the integration result, if the frequency value of the integration result is greater than 10Hz then go to step (2-3 ), if the frequency value is less than 10Hz, then end the operation; (2-3) Integrating the pulse signal between two adjacent zero-crossing points in the second pulse signal, and multiplying the integral result by a proportional coefficient, thereby obtaining a second gain adjustment amount; (2-4) Adjusting the gain amount of the SVC voltage regulator, and updating the gain amount, that is, subtracting the second gain adjustment amount from the gain amount of the SVC voltage regulator; (2-5) If the updated gain amount is within the gain limit value range, the gain amount of the SVC voltage regulator is taken as the updated gain amount; if the updated gain amount is greater than the maximum gain limit value value, the gain value of the SVC voltage regulator takes the maximum value of the gain limit value; if the updated gain value is less than the minimum value of the gain limit value, then the gain value of the SVC voltage regulator takes the minimum value of the gain limit value value. 5. The method according to claim 4, wherein in the step (2-1), judging whether the osc0 is stable comprises: setting a second threshold value and comparing it with the osc0, if the amplitude of the osc0 If the value is higher than the second threshold, the osc0 is unstable, and if the amplitude of the osc0 is lower than the second threshold within 150 ms, the osc0 is stable. 6. The method according to claim 2 or 4, wherein the gain limit value can be adjusted according to the capacity adjustment range of the SVC voltage regulator and the short-circuit capacity of the public connection point of the SVC voltage regulator access system set up.