Phase following device for GIS (gas insulated switchgear) same-frequency and same-phase test

Abstract

The invention discloses a phase following device for a GIS (Gas Insulated Switchgear) same-frequency and same-phase test, which comprises a first closed-loop phase-locked loop, a second closed-loop phase-locked loop and a third closed-loop phase-locked loop which are respectively connected with a first phase voltage, a second phase voltage and a third phase voltage of an operation side of a transformer substation so as to provide a phase and a frequency of a target voltage, the fourth closed-loop phase-locked loop is connected with the test side so as to synchronize the phase and frequency of the target voltage of the operation side of the transformer substation with the phase of the test-side voltage; the PI controller is connected with the first closed-loop phase-locked loop, the second closed-loop phase-locked loop, the third closed-loop phase-locked loop and the fourth closed-loop phase-locked loop so as to dynamically compensate the phase difference between the voltage of the operation side and the voltage of the test side of the transformer substation, and the phase out-of-control alarm structure is connected with the PI controller. And when the sum of the phases at the test side is not 0 and the phase difference between the voltage at the test side and the voltage at the operation side is greater than a preset threshold value, alarming and prompting.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electrical insulation technology, and in particular to a phase-following device for GIS synchronous frequency and phase testing. Background Technology

[0002] The application of gas-insulated switchgear (GIS) in substations is becoming increasingly widespread. Therefore, the operational status of GIS equipment is of great significance to the safe and stable operation of the entire power grid. After the expansion or maintenance of GIS bays, it is necessary to conduct AC withstand voltage tests on-site to detect and eliminate potential safety hazards such as internal insulation issues, ensuring the safe and reliable operation of the newly commissioned bays. To mitigate the risk of breakdown of equipment during the same-frequency and same-phase withstand voltage test of the GIS, it is necessary to ensure that the voltages on the test side and the operating side meet the same frequency and phase requirements.

[0003] While some research has addressed phase detection and phase following, the GIS in-phase and frequency withstand voltage test, due to its importance and the higher risk of breakdown and other hazards, places higher demands on its safe operation, necessitating a phase following design more suitable for this test. During operation, the voltage phase and frequency of the operating and test sides need to be dynamically adjusted to ensure a small phase difference. Furthermore, since three-phase imbalance can cause serious hazards, not only phase adjustment but also three-phase balance is required. Therefore, an alarm device is designed to issue an alert when the phase difference between the test and operating sides is too large and when there is three-phase imbalance, allowing for timely resolution of related problems and minimizing hazards. This design is more suitable for in-phase and frequency withstand voltage tests.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] To address the shortcomings or defects of the existing technology, a phase following device for GIS synchronous frequency and phase testing is provided.

[0006] The objective of this invention is achieved through the following technical solutions.

[0007] A phase-following device for GIS in-phase and frequency-synchronous testing includes,

[0008] A pre-synchronization control structure with the same frequency and phase includes,

[0009] The first closed-loop phase-locked loop, the second closed-loop phase-locked loop, and the third closed-loop phase-locked loop are respectively connected to the first phase voltage, the second phase voltage, and the third phase voltage on the operating side of the substation to provide the phase and frequency of the target voltage.

[0010] The fourth closed-loop phase-locked loop is connected to the test side to synchronize the phase and frequency of the target voltage on the substation operating side with the phase of the voltage on the test side.

[0011] The PI controller connects the first, second, third, and fourth closed-loop phase-locked loops to dynamically compensate for the phase difference between the operating and test voltages of the substation.

[0012] The phase failure alarm structure is connected to the PI controller. When the sum of the phases of each phase on the test side is not 0 and the phase difference between the voltage on the test side and the voltage on the operating side is greater than a predetermined threshold, an alarm is triggered.

[0013] In the phase-following device for the GIS synchronous frequency and phase test, the PI controller is through... The phase and frequency are dynamically adjusted, where f1 is the operating frequency, f2 is the test frequency, and K... p K i θ4 and θ3 are the proportional and integral adjustment coefficients of the PI controller, respectively, and the phases on the test side and the operating side are the phases on the test side and the operating side, respectively.

[0014] In the phase-following device for the GIS synchronous phase test, the phase difference between the voltage on the operating side and the test side is dynamically adjusted by a PI controller to adjust the phase difference and frequency difference until both are 0.

[0015] Compared with the prior art, the beneficial effects of this invention are as follows:

[0016] This invention can achieve pre-synchronization control of the phase and frequency of the operating side voltage and the test side voltage through dynamic adjustment, and can also monitor three-phase imbalance, for example, by generating an alarm when the phase difference between the operating side voltage and the test side voltage is too large, so as to react in time, reduce harm, and is more suitable for phase following in the process of same frequency and same phase withstand voltage test.

[0017] The description provided is merely an overview of the technical solution of this invention. In order to make the technical means of this invention clearer and more understandable, so that those skilled in the art can implement it according to the contents of the specification, and to make the described and other objects, features and advantages of this invention more obvious and understandable, specific embodiments of this invention are described below. Attached Figure Description

[0018] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0019] In the attached diagram:

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is the logic control flowchart of the present invention.

[0022] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0023] Specific embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0024] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0025] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0026] To better understand, such as Figures 1 to 2 As shown, a phase-following device for GIS synchronous frequency and phase testing includes,

[0027] A pre-synchronization control structure with the same frequency and phase includes,

[0028] The first closed-loop phase-locked loop, the second closed-loop phase-locked loop, and the third closed-loop phase-locked loop are respectively connected to the first phase voltage, the second phase voltage, and the third phase voltage on the operating side of the substation to provide the phase and frequency of the target voltage.

[0029] The fourth closed-loop phase-locked loop is connected to the test side to synchronize the phase and frequency of the target voltage on the substation operating side with the phase of the voltage on the test side.

[0030] The PI controller connects the first, second, third, and fourth closed-loop phase-locked loops to dynamically compensate for the phase difference between the operating and test voltages of the substation.

[0031] The phase failure alarm structure is connected to the PI controller. When the sum of the phases of each phase on the test side is not 0 and the phase difference between the voltage on the test side and the voltage on the operating side is greater than a predetermined threshold, an alarm is triggered.

[0032] In a preferred embodiment of the phase-following device for the GIS synchronous frequency and phase test, the PI controller is configured to... The phase and frequency are dynamically adjusted, where f1 is the operating frequency, f2 is the test frequency, and K... p K i Here, θ1 represents the proportional and integral control coefficients of the PI controller, and θ4 and θ3 represent the phases of the test and operating sides, respectively. First, let f1 = f2. At this point, there is a phase difference between the operating and test sides, causing the operating side frequency to change. Dynamic adjustment can then be performed to achieve pre-synchronization control with the same frequency and phase.

[0033] In a preferred embodiment of the phase following device for the GIS synchronous phase test, the phase difference between the voltage on the operating side and the test side is dynamically adjusted by a PI controller to adjust the phase difference and frequency difference until both are 0.

[0034] In one embodiment, the pre-synchronization control structure with the same frequency and phase synchronizes the voltage phase of each key phase through a PLL, and then achieves pre-synchronization control through dynamic adjustment. The phase loss alarm structure performs logical judgment on the key phases in the test and controls the alarm device. The logic control flowchart is as follows: Figure 2 As shown, the voltage phase difference between the operating side and the test side, as well as the sum of the three-phase phases, are judged. If the voltage phase difference between the operating side and the test side is too large and the sum of the three-phase phases is not 0, an alarm is triggered.

[0035] In one embodiment, four single-phase phase-locked loops are used to synchronize the three-phase voltage phases on the operating side and the voltage phases on the test side, such as... Figure 1 As shown, where e a e b ec These represent the three-phase voltages on the test side, u a u b u c θ1, θ2, and θ3 represent the three-phase voltages on the operating side, respectively, and θ4 represents the phase of the three-phase voltages on the operating side after synchronization by the PLL. The phase difference between the operating side and the test side voltages is dynamically compensated by a PI controller to achieve synchronous and phase-in-synchronous control. The phase difference between the operating side and the test side voltages is dynamically adjusted by the PI controller, along with the frequency difference, until both are zero.

[0036] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0037] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A phase-following device for GIS synchronous frequency and phase testing, characterized in that, It includes, A pre-synchronization control structure with the same frequency and phase includes, The first closed-loop phase-locked loop, the second closed-loop phase-locked loop, and the third closed-loop phase-locked loop are respectively connected to the first phase voltage, the second phase voltage, and the third phase voltage on the operating side of the substation to provide the phase and frequency of the target voltage. The fourth closed-loop phase-locked loop is connected to the test side to synchronize the phase and frequency of the target voltage on the substation operating side with the phase of the voltage on the test side. The PI controller connects the first, second, third, and fourth closed-loop phase-locked loops to dynamically compensate for the phase difference between the operating and test voltages of the substation. The phase failure alarm structure is connected to the PI controller. When the sum of the phases of each phase on the test side is not 0 and the phase difference between the voltage on the test side and the voltage on the operating side is greater than a predetermined threshold, an alarm is triggered.

2. The phase-following device for GIS synchronous frequency and phase testing as described in claim 1, characterized in that, Preferably, the PI controller is through The phase and frequency are dynamically adjusted, where f1 is the operating frequency, f2 is the test frequency, and K... p K i θ4 and θ3 are the proportional and integral adjustment coefficients of the PI controller, respectively, and the phases on the test side and the operating side are the phases on the test side and the operating side, respectively.

3. The phase-following device for GIS synchronous frequency and phase testing as described in claim 1, characterized in that, The phase difference between the operating side and the test side voltages is dynamically adjusted by a PI controller, along with the frequency difference, until both are zero.

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