Error Adjustable Voltage Signal Test Platform with Load Carrying Capacity

Abstract

The present invention discloses an error-adjustable voltage signal test platform with load-carrying capacity. The platform includes three lines, namely: a first line in which the power supply undergoes voltage transformation through a first transformer to provide a first voltage level; a second line in which voltage transformation is performed through a second transformer to provide a second voltage level; and a third line directly descending from the power supply to provide a third voltage level. At the rear end of the third line, there are n error-adjustable voltage transformers and a set of standard voltage transformers. The number of error-adjustable voltage transformers input is controlled in a parallel manner at the rear ends of the two transformers. At the very ends of the first line and the second line, there is a set of standard voltage transformers each. The present invention realizes the simulation of multiple different voltage levels, different operation modes, and different numbers of voltage transformers on one test platform through multiple transformers and disconnecting switches, and can simultaneously verify the accuracy, reliability, and universality of the PT metering performance state evaluation algorithm.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent measurement, and particularly relates to an error-adjustable voltage signal test platform with load-carrying capacity. Background Art

[0002] In order to develop the on-line monitoring and condition evaluation technology for the metering performance of instrument transformers, the goal of promoting the transformation of the supervision mode of potential transformers (PTs) at key points from periodic inspection to condition monitoring has been put forward. At present, many universities and research institutions have proposed various algorithms for evaluating the metering performance status of potential transformers, including the principal component analysis method and the information-physical correlation method. However, the verification of the accuracy, reliability, and universality of these algorithms is still in the initial research stage. Summary of the Invention

[0003] The purpose of the present invention is to provide an error-adjustable voltage signal test platform with load-carrying capacity to solve the verification problem of the algorithms for evaluating the metering performance status of potential transformers.

[0004] The present invention provides an error-adjustable voltage signal test platform with load-carrying capacity, which includes a power supply, a first transformer, a second transformer, and a third disconnecting switch;

[0005] The platform includes 3 lines, providing a total of 3 voltage levels, namely: the first line in which the power supply undergoes voltage transformation through the first transformer, providing the first voltage level; the second line in which the power supply undergoes voltage transformation through the second transformer, providing the second voltage level; and the third line directly coming down from the power supply, providing the third voltage level;

[0006] At the rear end of the third line, there are n groups of voltage transformers with adjustable errors and a group of standard voltage transformers; at the rear ends of the first transformer and the second transformer, the number of voltage transformers with adjustable errors input is controlled in parallel, and a group of standard voltage transformers are provided at the outermost ends of the first line and the second line;

[0007] The third disconnecting switch is connected to the first line and the second line and is located in front of the standard voltage transformers in the two lines; the third disconnecting switch is used for switching the operation mode of the platform. When the third disconnecting switch is opened, the platform provides primary signals of 3 different voltage levels; when simulating the same voltage signal, the third disconnecting switch is closed, and all the voltage transformers connected to the rear ends of the first transformer and the second transformer will operate under the same primary signal;

[0008] The voltage transformer with adjustable total error provides the original signal for the calibrator, and the standard voltage transformer provides the standard signal for the calibrator. The calibrator compares the standard signal with the signal of the voltage transformer with adjustable error to determine the accurate value of the adjusted error, which is used as the labeled quantity. The algorithm to be verified calculates the error value of each voltage transformer by receiving the signal of the voltage transformer with adjustable error, and compares this value with the data of the calibrator to complete the verification of the algorithm's accuracy. The platform completes the verification of the algorithm's reliability and universality by changing the number of voltage levels and the number of voltage transformers put into operation.

[0009] Further, the platform also includes a first disconnect switch and a second disconnect switch, which are respectively located behind the first transformer and the second transformer, and control the number of groups of voltage transformers with adjustable error switched on and off by the platform through controlling the on-off of the first line and the second line.

[0010] Further, the voltage transformer with adjustable error is adjusted in three levels internally. The first level consists of iron core T1 and windings F1 and F2, the second level consists of iron core T2 and windings F4 and F6, and the third level consists of iron core T3 and windings F8 and F10. The taps of windings F2, F6, and F10 can be adjusted;

[0011] Power supply windings F3 and F5 are provided between iron cores T1 and T2, and power supply windings F7 and F9 are provided between iron cores T2 and T3, improving the load-carrying capacity.

[0012] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0013] By adding independent windings inside the iron core, the present invention overcomes the problem of not being able to carry a load in the cascade error adjustment technology, realizes an error adjustment step of 0.01%, and at the same time has the ability to provide voltage power signals to the outside. Each 0.2-class voltage transformer of the present invention can provide a load-carrying capacity of 2VA, fully meeting the power consumption requirements of the signal terminals of the current voltage transformer metering performance status evaluation device.

[0014] Through multiple transformers and disconnect switches, the present invention realizes the simulation of multiple different voltage levels, different operating modes, and different numbers of voltage transformers on one test platform, considering all operating modes of voltage transformers in the substation, greatly improving the test efficiency and test flexibility, and can simultaneously verify the accuracy, reliability, and universality of the voltage transformer metering performance status evaluation algorithm. Description of the Drawings

[0015] Figure 1 It is the schematic diagram of the test platform for the voltage signal with adjustable error and load-carrying capacity;

[0016] Figure 2It is the internal schematic diagram of a voltage transformer with adjustable error. Specific embodiments

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] In view of the verification status of the algorithm for evaluating the metering performance of voltage transformers, the present invention proposes a test platform for voltage signals with adjustable error and load-carrying capacity. This platform can simulate the typical operation modes of voltage transformers in substations, simulate various voltage levels and various system operation modes, and the error of each voltage transformer can be independently adjusted to verify the accuracy, reliability and universality of the algorithm for evaluating the metering performance of voltage transformers. This platform meets all the operation modes and quantities of voltage transformers in existing substations and can be used as a verification platform for the algorithm for evaluating the metering performance of voltage transformers to provide verification data for companies, universities and research institutions engaged in algorithm development, and has great market benefits.

[0019] The objectives of the present invention include: 1. Simulate the operation of voltage transformers in substations with different voltage levels under low voltage; 2. Simulate the operation of voltage transformers under different operation modes in substations; 3. Arbitrarily select the number of voltage transformers participating in the operation and control the error value of each voltage transformer; 4. Provide training data for the verification of the algorithm for evaluating the metering performance of voltage transformers.

[0020] A design scheme of a test platform for voltage signals with adjustable error and load-carrying capacity of the present invention:

[0021] 1) The principle of the present invention is as Figure 1 shown. Through the design of transformers and disconnectors, this platform realizes the simulation of different voltage levels and different operation modes in the substation;

[0022] 2) According to Figure 1It can be seen that there are three power levels in the power supply section, namely a voltage level directly from the power supply and two voltage levels obtained through voltage transformation by Transformer 1 and Transformer 2, achieving the design that the same input voltage appears as three voltage levels on the test platform; at the back end of the directly incoming power line, there are n sets of voltage transformers with adjustable errors and a set of 0.01-class standard voltage transformers. At the back ends of Transformer 1 and Transformer 2, the number of input voltage transformers can be controlled in parallel according to test requirements, and each line end is equipped with a set of 0.01-class standard voltage transformers; Disconnecting Switches 1 and 2 can control the total number of voltage transformers with adjustable errors switched on and off on this platform; Disconnecting Switch 3 is used for system operation mode switching. When Disconnecting Switch 3 is opened, the primary signals of three different voltage levels provided by this platform are available. When simulating the same voltage signal, Disconnecting Switch 3 is closed, and all voltage transformers connected to the back ends of Transformer 1 and Transformer 2 will operate under the same primary signal;

[0023] 3) Figure 1 Among them, all voltage transformers with adjustable errors can provide original signals to both external and internal calibrators simultaneously. The standard voltage transformer signal only provides signals to the internal calibrator. The internal calibrator compares the standard signal with the signal of the voltage transformer with adjustable errors to determine the accurate value of the adjusted error. This value is used as the tagged quantity, while the external algorithm can calculate the error value of each voltage transformer only by receiving the voltage transformer with adjustable errors. This value is compared with the calibrator data to check the difference between the two to complete the verification of the algorithm accuracy; the platform completes the verification of the algorithm reliability and universality by changing the number of voltage levels and the number of voltage transformers put into operation;

[0024] 4) The internal principle of the voltage transformer with adjustable errors is as Figure 2 shown. U1 is the input voltage value, U2 is the output voltage value, and it is adjusted in three levels internally. The first level consists of iron core T1, windings F1 and F2, the second level consists of iron core T2, windings F4 and F6, and the third level consists of iron core T3, windings F8 and F10. The taps of the step windings F2, F6, and F10 to be adjusted can be adjusted. When the tap of F2 is designed to be 100 turns, when F4 moves up and down once, the adjustment step of the output voltage value of U1 is 1%. Similarly, when the tap of F6 is designed to be 10 turns, when F8 moves up and down once, the adjustment step of the output voltage value of U1 is 0.1%. When the tap of F10 is designed to be 10 turns, when the final output terminal moves up and down once, the adjustment step of the output voltage value of U1 is 0.01%;

[0025] 5) Figure 2Among them, F3, F5, F7, and F9 are power supply windings. Since the voltage transformer with adjustable error needs to provide voltage signals to the outside, the ordinary cascaded error adjustment design has no load-carrying capacity. When equipment is connected to the backend, the voltage will drop, resulting in a large difference between the actual value and the designed value of the error adjustment. In the present invention, a separate power supply winding design is added inside the voltage transformer with adjustable error, and voltage is directly supplied to the cascaded iron cores T2 and T3 from the first-stage iron core T1 of U1.

[0026] This platform can simulate the operation of voltage transformers in substations with voltage levels of 110 kV and above under various different system wiring modes such as single bus, double bus, double bus + bypass bus, etc. The error of each voltage transformer can be adjusted independently, and the adjustment step is 0.01%. This platform can provide 60 - 90 voltage signals externally, providing tag data and detection data for verifying the accuracy, reliability, and universality of the algorithm for evaluating the metrological performance status of voltage transformers.

[0027] An example of a test platform for an error-adjustable voltage signal with load-carrying capacity according to the present invention:

[0028] 1) Simulate the operation output of 6 groups of voltage transformers with only one voltage level in the substation.

[0029] Select 100V voltage input at the power supply side. Transformers 1 and 2 select a turns ratio of 100V:100V. The turns ratios of all error-adjustable voltage transformers and standard voltage transformers are 100V:100 / √3V. Isolating switches 1, 2, and 3 are all closed. The primary voltage signals of the entire test platform are exactly the same. Connect 2 groups of 0.2-level error-adjustable voltage transformers and 1 group of 0.01-level standard voltage transformers in parallel at the power supply input end. Connect 2 groups of 0.2-level error-adjustable voltage transformers in parallel at both the power supply input end and the backend of transformer 1. Simultaneously supply the secondary output signals of the 6 groups of 0.2-level voltage transformers to the internal calibrator and the external device for evaluating the metrological performance status of the voltage transformer. Simultaneously supply the secondary output signal of 1 group of 0.01-level standard voltage transformer to the internal calibrator. At this time, the internal calibrator will calculate the true error value of each group of 0.2-level voltage transformers, and this value is used as the tag quantity. The device for evaluating the metrological performance status of the voltage transformer relies on its own algorithm to complete the calculation of the errors of the 6 groups of voltage transformers without the signal of the standard voltage transformer. The calculated value is compared with the tag quantity calculated by the calibrator. The smaller the difference between the two, the higher the calculation accuracy.

[0030] 2) Simulate 3 voltage levels in the substation, including 2 groups of voltage transformers with one voltage level, 4 groups of voltage transformers with one voltage level, and 6 groups of voltage transformers with one voltage level, totaling 12 groups of voltage transformers for operation output simulation.

[0031] The power supply side selects 380V, and at the back end, 2 groups of 0.2-level error-adjustable voltage transformers with a transformation ratio of 380V:100 / √3V and 1 group of 0.01-level standard voltage transformers are configured; Transformer 1 selects a transformation ratio of 380V:100V, and at the back end, 4 groups of 0.2-level error-adjustable voltage transformers with a transformation ratio of 100V:100 / √3V are configured; Transformer 2 selects a transformation ratio of 380V:80V, and at the back end, 6 groups of 0.2-level error-adjustable voltage transformers with a transformation ratio of 80V:100 / √3V are configured. Isolating switches 1 and 2 are closed, and isolating switch 3 is open. In this mode, the test platform simulates the operation conditions of 12 groups of voltage transformers at 3 different voltage levels in a substation. The signal provision and calculation at the back end are the same as above. This solution can verify the calculation reliability of the algorithm when multiple groups of voltage transformers are at different voltage levels.

[0032] By simulating different voltage levels, different operation modes, and different numbers of voltage transformers, it is possible to verify the universality of various existing algorithms for evaluating the metering performance status of voltage transformers, providing data support for finding out which algorithm is suitable for which wiring method and the calculation of the operation error of the most suitable number of voltage transformers.

[0033] In summary, for the voltage transformer with adjustable error designed in the present invention, an independent power supply winding is added to the cascaded winding core. By adding an independent power supply winding at each stage, the load-carrying capacity of the voltage transformer with adjustable error is improved, ensuring that a 0.01% error adjustment step is achieved with 3-stage cascade, and a breakthrough in high-precision error adjustment technology with load-carrying capacity is realized;

[0034] The present invention realizes the simulation of the operation errors of multiple voltage levels, multiple operation modes, and multiple groups of voltage transformers through the parallel connection of 3 transformers and 3 isolating switches, greatly improving the flexibility of the test bench;

[0035] The present invention realizes the simulation of all operation modes of voltage transformers in substations with voltage levels of 110 kV and above. One platform can verify the three indicators of accuracy, reliability, and universality of the algorithm for evaluating the metering performance status of voltage transformers.

[0036] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An error-adjustable voltage signal test platform with load-carrying capacity, characterized in that The platform includes a power supply, a first transformer, a second transformer, and a third disconnecting switch; The platform includes three lines, providing a total of three voltage levels, namely: the first line where the power supply undergoes voltage transformation through the first transformer, providing the first voltage level; the second line where the power supply undergoes voltage transformation through the second transformer, providing the second voltage level; and the third line directly from the power supply, providing the third voltage level; At the rear end of the third line, there are n sets of voltage transformers with adjustable error, as well as a set of standard voltage transformers; at the rear ends of the first transformer and the second transformer, the number of voltage transformers with adjustable error input is controlled in parallel, and there is a set of standard voltage transformers at the very ends of the first line and the second line; The third disconnecting switch connects the first line and the second line and is located in front of the standard voltage transformers in the two lines; The third disconnecting switch is used for switching the operating mode of the platform. When the third disconnecting switch is open, the platform provides primary signals of three different voltage levels; when simulating the same voltage signal, the third disconnecting switch is closed, and all the voltage transformers connected to the rear ends of the first transformer and the second transformer will operate under the same primary signal; All the voltage transformers with adjustable error provide original signals to the calibrator, and the standard voltage transformers provide standard signals to the calibrator. The calibrator compares the standard signal with the signals of the voltage transformers with adjustable error to determine the accurate value of the adjusted error, and this value serves as the labeled quantity; The algorithm to be verified calculates the error value of each voltage transformer by receiving the signals of the voltage transformers with adjustable error, and this value is compared with the data of the calibrator to complete the verification of the algorithm's accuracy; The platform completes the verification of the algorithm's reliability and universality by changing the number of voltage levels and the number of voltage transformers put into operation; Among them, the voltage transformer with adjustable error has three - level regulation inside. The first level consists of iron core T1 and windings F1 and F2, the second level consists of iron core T2 and windings F4 and F6, and the third level consists of iron core T3 and windings F8 and F10. The taps of windings F2, F6, and F10 can be adjusted; There are power - supply windings F3 and F5 between iron cores T1 and T2, and power - supply windings F7 and F9 between iron cores T2 and T3 to improve the load - carrying capacity.

2. The error-adjustable voltage signal test platform with load-carrying capacity according to claim 1, wherein The platform also includes a first disconnecting switch and a second disconnecting switch. The first disconnecting switch and the second disconnecting switch are respectively located behind the first transformer and the second transformer, and control the total number of voltage transformers with adjustable error switched on and off in the platform by controlling the on - off of the first line and the second line.

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