Simulation test device and verification method of transformer on-load tap-changer tester

Abstract

The invention provides a simulation test device and a verification method of a transformer on-load tap-changer tester, the simulation test device comprises a simulation part and a time control unit, the simulation part comprises a signal input unit, an inductive load array, a high-precision resistor array, an AC solid-state relay array and a signal output unit; the inductive load array is sequentially connected with the high-precision resistor array and the alternating-current solid-state relay array; the time control unit is connected with the alternating-current solid-state relay array; the time control unit simulates a time sequence signal in the switching process of the on-load tap-changer to be tested, and the simulation part simulates load impedance conversion in the switching process of the on-load tap-changer to be tested; the measurement of AC / DC parameters of the transformer on-load tap-changer tester is realized. According to the invention, the transformer on-load tap-changer tester integrates alternating current and direct current tests of the transformer on-load tap-changer, so that simulation test and verification of the transformer on-load tap-changer tester in an alternating current and direct current method are realized, and the effectiveness and accuracy of simulation verification are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of simulation equipment of an on-load tap changer tester of an alternating current method transformer, and in particular relates to a simulation test device and a calibration method of an on-load tap changer tester of a transformer. Background Art

[0002] The transformer on-load tap changer is a switch device that provides a constant voltage for the transformer when the load changes. At present, most transformers with a capacity of 10MVA and above are equipped with on-load tap changers, and power equipment and users are increasingly using on-load voltage-regulating transformers. The on-load tap changer is its key and relatively expensive component. The transformer on-load switch tester is a comprehensive measuring instrument used to measure and analyze the electrical performance indicators of the on-load tap changers of power transformers and special transformers in power equipment. It can analyze and find the cause of the failure of the on-load tap changer to ensure the normal and safe operation of the on-load tap changer, and is widely used in power equipment. The transformer on-load switch tester has two measurement methods: DC method and AC method. The DC method is used for testing the tap changer when it leaves the factory or is overhauled, mainly testing the transition resistance, transition time and three-phase disconnection asynchronous time; the AC method is used for the tap changer with winding test after hoisting, mainly testing the transition time waveform and three-phase disconnection asynchronous time.

[0003] As an improvement, there are mature simulation methods for transformer on-load switch testers based on the DC measurement principle. At present, there are simulation test devices for transformer on-load tap changer testers based on a combination of physical resistors and power field effect tubes, such as a transformer on-load tap changer transition resistance simulation test device based on the real-time feedback principle of power field effect tubes and operational amplifiers. However, the above devices are not suitable for transformer on-load tap changer testers based on the simulation AC measurement principle.

[0004] As a further improvement, a calibration device for transformer on-load tap changer tester has been developed, which uses two power field effect transistors and operational amplifier feedback circuits to work in the positive and negative half-cycles of the AC signal respectively, and is used to calibrate transformer on-load tap changer testers based on the AC measurement principle. However, when testing the AC transformer on-load tap changer tester, the transformer windings are often tested together, so the above device is not applicable. In summary, the current simulation test device for transformer on-load tap changer testers cannot simulate both AC and DC transformer on-load tap changer testers at the same time, and the measurement parameter accuracy of the transformer on-load tap changer tester is not high, resulting in poor effectiveness of simulation and calibration. Summary of the invention

[0005] The object of the present invention is to provide a simulation test device and a calibration method for a transformer on-load tap changer tester, so as to solve the problem that the simulation test device of the current transformer on-load tap changer tester cannot simulate the transformer on-load tap changer tester of the AC method and the DC method at the same time, and the measurement parameter accuracy of the transformer on-load tap changer tester is not high, resulting in poor effectiveness of simulation and calibration.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: The present invention discloses a simulation test device for a transformer on-load tap changer tester, the simulation test device comprises a simulation part and a time control unit configured thereon, the simulation part comprises a signal input unit, an inductive load array, a high-precision resistor array, an AC solid-state relay array and a signal output unit; wherein: The inductive load array, the high-precision resistor array, and the AC solid-state relay array respectively include a number of inductive loads, high-precision resistors, and AC solid-state relays connected in parallel; each inductive load is sequentially connected to the corresponding high-precision resistor and AC solid-state relay; the time control unit is connected to the control end of each AC solid-state relay; the test signal input unit is connected to the inductive load array, and the test signal output unit is connected to the AC solid-state relay array; When the simulation test device is connected to the transformer on-load tap changer, the inductive load array, high-precision resistor array and AC solid-state relay array can simulate the load impedance transformation of the on-load tap changer during the switching process, so that the transformer on-load tap changer tester can measure the AC and DC parameters of the transformer on-load tap changer.

[0007] In some embodiments, the inductive load array is used to simulate the inductive load before and after the on-load tap changer of the transformer is switched.

[0008] In some embodiments, a high-precision resistor array is used to simulate the resistive load before and after the on-load tap changer of the transformer is switched.

[0009] Furthermore, several high-precision resistors in the high-precision resistor array are precision metal foil resistors.

[0010] In some implementations, the AC solid-state relay array is used to simulate: load connection during the transformer on-load tap changer gear switching process, load connection before the control gear switching, and load connection after the control gear switching.

[0011] In some implementations, the time control unit is used to simulate the transition time parameter during the gear switching process of the transformer on-load tap changer by controlling the opening and closing time of each AC solid-state relay.

[0012] In some embodiments, when the transformer on-load tap changer tester performs an AC test, the simulation test device outputs a 40V-800V AC voltage test signal and then connects to the transformer on-load tap changer through the transformer winding.

[0013] In some embodiments, when the transformer on-load tap changer tester performs a DC method test, the simulation test device outputs a 0.1A-2A DC current test signal and then is connected to the transformer on-load tap changer.

[0014] In some embodiments, the time control unit is used to simulate a timing signal of the transformer on-load tap changer during a switching process.

[0015] The present invention also provides a calibration method for a transformer on-load tap changer tester, comprising the following steps: When the transformer on-load tap changer tester performs an AC method test, the test signal output unit of the analog test device of the transformer on-load tap changer tester is connected to the transformer winding and then connected to the transformer on-load tap changer; or, when the transformer on-load tap changer tester performs a DC method test, the test signal output unit of the analog test device of the transformer on-load tap changer tester is connected to the transformer on-load tap changer; Set the corresponding parameters of the simulation test device for the AC method test of the transformer on-load tap changer tester and the DC method test of the transformer on-load tap changer tester; Start the simulation test. The transformer on-load tap changer tester is tested in the test environment provided by the simulation test device. The load impedance transformation of the transformer on-load tap changer during the switching process is simulated by the inductive load array, high-precision resistor array and AC solid-state relay array in the simulation test device. The transformer on-load tap changer tester outputs the measurement results. By comparing the measurement results of the transformer on-load tap changer tester with the preset expected values, it is determined whether the measurement precision and accuracy of the tester meet the requirements, and then the transformer on-load tap changer tester is calibrated.

[0016] Compared with the prior art, the simulation test device and calibration method of the transformer on-load tap changer tester of the present invention have the following beneficial technical effects.

[0017] The invention discloses a simulation test device for a transformer on-load tap changer tester. The simulation test device comprises a simulation part and a time control unit configured thereon. The simulation part comprises a signal input unit, an inductive load array, a high-precision resistor array, an AC solid-state relay array and a signal output unit. The inductive load array, the high-precision resistor array and the AC solid-state relay array respectively comprise a plurality of parallel-connected inductive loads, high-precision resistors and AC solid-state relays. Each inductive load is sequentially connected to a corresponding high-precision resistor and an AC solid-state relay. The time control unit is connected to a control end of each AC solid-state relay. The test signal input unit is connected to the inductive load array, and the test signal output unit is connected to the AC solid-state relay array. When the simulation test device is connected to the transformer on-load tap changer, the inductive load array, the high-precision resistor array and the AC solid-state relay array can simulate the load impedance transformation of the on-load tap changer during the switching process, so that the transformer on-load tap changer tester can measure the AC and DC parameters of the transformer on-load tap changer. Based on the above, the present invention uses high-precision resistors, inductive loads and programmable AC relay arrays to simulate the parameters such as transition resistance and transition time before and after the gear switching process of the transformer on-load tap changer, and realizes the simulation of the transformer on-load tap changer tester of the AC method and the DC method. Compared with the traditional simulation method and device, the present invention integrates the AC and DC simulation functions into one, solves the problem that the measurement parameters of the transformer on-load tap changer tester of the AC method are difficult to effectively simulate, improves the effectiveness and accuracy of the simulation, and the simulation test device of the present invention has a high degree of automation, strong overall reliability, high work efficiency, and has certain practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 The present invention is a schematic diagram of the architecture of a simulation test device in a simulation test device and a calibration method of a transformer on-load tap changer tester. DETAILED DESCRIPTION

[0020] 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 are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0023] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0024] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] How to provide a simulation test device that can accurately simulate a transformer on-load tap changer tester, so as to realize the integrated simulation of AC and DC measurement parameters of the transformer on-load tap changer tester.

[0027] like Figure 1 As shown, the simulation test device of the transformer on-load tap changer tester of the present invention comprises a simulation part and a time control unit configured thereon, and the simulation part comprises a signal input unit, an inductive load array, a high-precision resistor array, an AC solid-state relay array and a signal output unit; wherein: The inductive load array, the high-precision resistor array, and the AC solid-state relay array respectively include a number of inductive loads, high-precision resistors, and AC solid-state relays connected in parallel; each inductive load is sequentially connected to the corresponding high-precision resistor and AC solid-state relay; the time control unit is connected to the control end of each AC solid-state relay; the test signal input unit is connected to the inductive load array, and the test signal output unit is connected to the AC solid-state relay array; When the simulation test device is connected to the transformer on-load tap changer, the inductive load array, high-precision resistor array and AC solid-state relay array can simulate the load impedance transformation of the on-load tap changer during the switching process, so that the transformer on-load tap changer tester can measure the AC and DC parameters of the transformer on-load tap changer.

[0028] The present invention is composed of four parts: an inductive load array, a high-precision resistor array, an AC solid-state relay array, and a time control unit. The test signal input terminal of the simulation test device of the transformer on-load tap changer tester is connected to the inductive load array; the inductive load array is connected to the high-precision resistor array; the high-precision resistor array is connected to the AC solid-state relay array; the AC solid-state relay array is connected to the test signal output terminal; and the time control unit is connected to the control end of the AC solid-state relay array. The present invention provides a controllable test environment for the transformer on-load tap changer tester by simulating the load impedance transformation of the transformer on-load tap changer during the switching process. The verification device simulates the on-load tap changer switching process timing signal through the time control unit, and the inductive load array, the high-precision resistor array, and the AC solid-state relay array simulate the load impedance transformation during the on-load tap changer switching process, thereby realizing the integrated verification of the transformer on-load tap changer tester on AC and DC measurement parameters. The present invention can simulate the load impedance transformation of the real transformer on-load tap changer, ensure that the tester obtains accurate data during the test process, thereby improving the verification efficiency and accuracy of the transformer on-load tap changer tester, and reducing the verification cost.

[0029] In some embodiments, the inductive load array of the present invention is used to simulate the inductive load before and after the on-load tap changer of the transformer is switched. When the simulation test device of the present invention is used for DC method testing, its inductive load value is zero. The inductive load array of the present invention is used to simulate the inductive load before and after the on-load tap changer of the transformer is switched. It is achieved by connecting multiple inductive loads in parallel, accurately simulating the change of inductive load during the switching process of the on-load tap changer of the transformer, improving the accuracy of the test, and through the above design, it is easy to adjust the size and number of inductive loads to meet the needs of different tests.

[0030] Furthermore, the high-precision resistor array of the present invention is used to simulate the resistive load before and after the on-load tap changer of the transformer is switched, and is realized by connecting multiple high-precision resistors in parallel. As a specific embodiment, the high-precision resistor of the present invention can be, but is not limited to, composed of precision metal foil resistors, so as to ensure the stability of the simulated parameters of the simulation test device. The present invention provides accurate resistive load simulation, so that the tester can measure the resistive parameters more accurately.

[0031] In some embodiments, the AC solid-state relay array of the present invention is used to simulate: load connection during the on-load tap changer gear switching process of the transformer, load connection before the gear switching, and load connection after the gear switching. The AC solid-state relay array of the present invention achieves precise control of load connection and connection, simulates the real switching process, improves the reliability and accuracy of the test, and reduces interference during the test process.

[0032] In some embodiments, the time control unit of the present invention is used to simulate the timing signal of the transformer on-load tap changer during the switching process. Specifically, the time control unit is used to simulate the transition time parameters during the gear switching process of the transformer on-load tap changer by accurately controlling the opening and closing time of each AC solid-state relay. The present invention accurately simulates the timing signal, which helps the tester to more accurately measure the timing parameters, accurately simulates the transition time parameters, which helps the tester to more accurately measure the transition time and other parameters, improves the flexibility and accuracy of the test, and adapts to different test requirements.

[0033] The simulation test device and calibration method of a transformer on-load tap changer tester of the present invention are further described in detail below through specific embodiments.

[0034] When the transformer on-load tap changer tester performs an AC test, a 40V-800V AC voltage test signal is output, which is connected to the on-load tap changer after passing through the transformer winding. When the transformer on-load tap changer tester performs a DC test, a 0.1A-2A DC current test signal is output, which is connected to the on-load tap changer. As the on-load tap changer switches gears, the load impedance in the test loop changes, causing the loop current / voltage to change. The tester obtains parameters such as the transition time and transition resistance of the tap changer through the changes in loop voltage and current. The present invention provides an adjustable AC voltage test signal, which meets the test requirements of different voltage levels and ensures the accuracy and reliability of AC and DC tests.

[0035] The present invention also provides a calibration method for a transformer on-load tap changer tester: when the transformer on-load tap changer tester performs an AC method test, a test signal output unit of an analog test device of the transformer on-load tap changer tester is connected to a transformer winding and then connected to the transformer on-load tap changer; or, when the transformer on-load tap changer tester performs a DC method test, a test signal output unit of the analog test device of the transformer on-load tap changer tester is connected to the transformer on-load tap changer; Set the corresponding parameters of the simulation test device for the AC method test of the transformer on-load tap changer tester and the DC method test of the transformer on-load tap changer tester; Start the simulation test. The transformer on-load tap changer tester is tested in the test environment provided by the simulation test device. The load impedance transformation of the transformer on-load tap changer during the switching process is simulated by the inductive load array, high-precision resistor array and AC solid-state relay array in the simulation test device. The transformer on-load tap changer tester outputs the measurement results. By comparing the measurement results of the transformer on-load tap changer tester with the preset expected values, it is determined whether the measurement precision and accuracy of the tester meet the requirements, and then the transformer on-load tap changer tester is calibrated.

[0036] The present invention provides a test environment through a simulation test device. By connecting the simulation test device, setting parameters, starting simulation test, and comparing the measurement results with the preset expected values, the transformer on-load tap changer tester is calibrated according to the difference between the measurement results and the preset expected values. The calibration method is simple and effective, and ensures the measurement precision and accuracy of the tester. The method of the present invention can be applied to transformer on-load tap changer testers of different models. The transformer on-load tap changer tester can be tested and calibrated by the DC method and the AC method at the same time, and the accuracy of the calibration is guaranteed on the basis of improving the calibration efficiency.

[0037] Based on the above, specifically, in some embodiments, the present invention sets the voltage between the test signal input and output ports to be U , the current is I , the inductive reactance of the inductive load 1-n is X 1- X n , the resistance value of high precision resistor 1-n is R 1- R n ,but U / I =( R i +j X i), i is the serial number of the corresponding AC solid-state relay closed loop. The transformer on-load tap changer tester calculates the transition resistance, transition time and other parameters by measuring the U and I values ​​and their changes. Initially, the AC solid-state relay 1 is closed, and the loop impedance is R 1+j X 1. Simulate the initial state of the transformer on-load tap changer gear switching; t At time 1, the time control unit AC solid-state relay 2 is closed, and AC solid-state relay 1 is disconnected. At this time, the loop impedance is R 2+j X 2. Simulate the state of the transformer on-load tap changer after the first switching; t At time 2, the time control unit AC solid-state relay 3 is closed, and AC solid-state relay 2 is disconnected. At this time, the loop impedance is R 3+j X 3. Simulate the status of the transformer on-load tap changer after the second switching. t 2- t The time value of 1 is the transition time value of the first segment; t n At the moment, the time control unit AC solid-state relay (n+1) is closed, and the AC solid-state relay n is disconnected. At this time, the loop impedance is R n+1 +j X n+1 , simulating the state of the transformer on-load tap changer after the nth switching. t n - t n-1 The time value is the (n-1)th transition time value. X 1- X n , R 1- R n Parameters, program control t 1- t n Parameters can accurately simulate the changes in electrical parameters during the operation of the transformer on-load tap changer, and realize the calibration of the AC and DC transformer on-load tap changer testers.

[0038] In summary, the present invention aims at the simulation demand of the on-load tap changer tester of the transformer using the AC method, proposes a simulation test device and a calibration method for the on-load tap changer tester of the transformer, solves the simulation technical problem of the on-load tap changer tester of the transformer using the AC method, improves the accuracy of the simulation, and through the device, it is possible to simulate the on-load tap changer testers of the AC and DC transformers at the same time, thereby realizing the calibration of the on-load tap changer testers of the transformer using the AC and DC methods, which has certain practical significance.

[0039] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the specification and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. The simulation test device of the transformer on-load tap changer tester is characterized by: The simulation test device includes a simulation part and a time control unit configured thereon, wherein the simulation part includes a signal input unit, an inductive load array, a high-precision resistor array, an AC solid-state relay array and a signal output unit; wherein: The inductive load array, high-precision resistor array, and AC solid-state relay array respectively include a number of inductive loads, high-precision resistors, and AC solid-state relays connected in parallel; each of the inductive loads is sequentially connected to a corresponding high-precision resistor and an AC solid-state relay; the time control unit is connected to a control end of each AC solid-state relay; the test signal input unit is connected to the inductive load array, and the test signal output unit is connected to the AC solid-state relay array; When the simulation test device is connected to the transformer on-load tap changer, the inductive load array, the high-precision resistor array and the AC solid-state relay array can simulate the load impedance transformation of the on-load tap changer during the switching process, so that the transformer on-load tap changer tester can measure the AC and DC parameters of the transformer on-load tap changer.

2. The simulation test device of the transformer on-load tap changer tester according to claim 1, characterized in that: The inductive load array is used to simulate the inductive load before and after the transformer on-load tap changer is switched.

3. The simulation test device of the transformer on-load tap changer tester according to claim 1, characterized in that: The high-precision resistor array is used to simulate the resistive load before and after the transformer on-load tap changer is switched.

4. The simulation test device of the transformer on-load tap changer tester according to claim 3, characterized in that: Several high-precision resistors in the high-precision resistor array are precision metal foil resistors.

5. The simulation test device of the transformer on-load tap changer tester according to claim 1, characterized in that: The AC solid-state relay array is used to simulate: load connection during the gear switching process of the transformer on-load tap changer, load connection before the control gear switching, and load connection after the control gear switching.

6. The simulation test device of the transformer on-load tap changer tester according to claim 1, characterized in that: The time control unit is used to simulate the timing signal of the transformer on-load tap changer during the switching process.

7. The simulation test device of the transformer on-load tap changer tester according to claim 6, characterized in that: The time control unit is used to simulate the transition time parameter in the gear switching process of the transformer on-load tap changer by controlling the opening and closing time of each AC solid-state relay.

8. The simulation test device of the transformer on-load tap changer tester according to claim 1, characterized in that: When the transformer on-load tap changer tester performs an AC test, the simulation test device outputs a 40V-800V AC voltage test signal and then connects to the transformer on-load tap changer through the transformer winding.

9. The simulation test device of the transformer on-load tap changer tester according to claim 1, characterized in that: When the transformer on-load tap changer tester performs a DC method test, the simulation test device outputs a 0.1A-2A DC current test signal and is then connected to the transformer on-load tap changer.

10. The simulation test device of the transformer on-load tap changer tester and the calibration method of the transformer on-load tap changer tester according to any one of claims 1 to 9 are characterized in that: The steps include: When the transformer on-load tap changer tester performs an AC method test, the test signal output unit of the analog test device of the transformer on-load tap changer tester is connected to the transformer winding and then connected to the transformer on-load tap changer; or, when the transformer on-load tap changer tester performs a DC method test, the test signal output unit of the analog test device of the transformer on-load tap changer tester is connected to the transformer on-load tap changer; Set the corresponding parameters of the simulation test device for the AC method test of the transformer on-load tap changer tester and the DC method test of the transformer on-load tap changer tester; Start the simulation test. The transformer on-load tap changer tester is tested in the test environment provided by the simulation test device. The load impedance transformation of the transformer on-load tap changer during the switching process is simulated by the inductive load array, high-precision resistor array and AC solid-state relay array in the simulation test device. The transformer on-load tap changer tester outputs the measurement results. By comparing the measurement results of the transformer on-load tap changer tester with the preset expected values, it is determined whether the measurement precision and accuracy of the tester meet the requirements, and then the transformer on-load tap changer tester is calibrated.

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