General power transformer winding deformation frequency response detection unit
By introducing a dial switch module and a selection knob into the power transformer winding detection unit, automatic identification of winding phases is achieved, solving the problem of non-universal detection units in existing technologies, improving production and testing efficiency, reducing costs, and enhancing test safety and flexibility.
Patent Information
- Application Number
- CN202511104507.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-10-31
AI Technical Summary
Existing power transformer winding frequency response detection units require manual recording of winding phase information during production, lacking an automatic identification mechanism. This results in the detection units being non-universal, leading to low production and testing efficiency and high costs.
A general-purpose power transformer winding deformation frequency response detection unit was designed. It uses a DIP switch module to automatically identify the winding phase, switches the static contact by selecting a knob, and the main control CPU identifies the winding identity. It also has a spare phase pin, which enables flexible deployment and fault tolerance, and reduces replacement costs.
It improves the flexibility and testing efficiency of the detection unit, reduces production and testing costs, reduces human error, enables automatic identification and remote testing, and enhances testing safety and efficiency.
Smart Images
Figure CN120870973A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of power equipment measurement technology, specifically relating to a general power transformer winding deformation frequency response detection unit. Background Technology
[0002] Power transformers are crucial equipment in power systems, mostly three-phase or single-phase transformers, typically composed of multiple windings at high, medium, and low voltage levels. Transformer winding frequency response analysis (FRA) is an important method for determining whether transformer windings are deformed. The method involves injecting a sweep frequency signal into the excitation terminal of the tested winding, measuring the amplitude ratio of the response voltage at the response terminal to the reference voltage at the excitation terminal, and generating a frequency response characteristic curve. Existing distributed FRA detection systems require the deployment of a dedicated detection unit at each winding's output terminal.
[0003] Currently, during the production of existing testing units, each unit requires manual recording of a specific winding phase (A / B / C / N phases of high, medium, and low voltage) information. This winding phase information is then fixedly integrated into the testing unit using binary encoding. Each testing unit is pre-set to match a specific winding phase during production; for example, a phase A testing unit can only be installed on phase A windings, and a phase B testing unit can only be installed on phase B windings. As described above, the current distributed testing unit deployment requires each winding to have a corresponding phase testing unit installed, lacking an automatic phase identification mechanism. This prevents it from being universally applicable across three-phase transformer windings, and production must be tailored to different phase windings, resulting in inflexible deployment and low production and testing efficiency. Consequently, if a phase setting of a testing unit fails, the entire testing unit must be replaced, leading to a lack of redundancy, high costs, and time consumption. Summary of the Invention
[0004] The purpose of this invention is to provide a general-purpose power transformer winding deformation frequency response detection unit.
[0005] The present invention includes a detection unit body and a clamping device. The clamping device is fixedly installed below the detection unit body, and the detection unit body is installed on the output terminal or end tap of each winding of the transformer under test through the clamping device.
[0006] The outer casing of the detection unit body is equipped with a selection knob and a unit power switch, which controls the power supply of the detection unit body to be turned on and off. Inside the outer casing of the detection unit body are a main control CPU, a communication module, an excitation module, a sampling module, a DIP switch, an excitation module switch, a sampling module switch, a grounding switch, and a detection port. The communication module, excitation module, and sampling module are connected to the main control CPU, which is used to receive instructions from the centralized control platform and control the excitation module, sampling module, excitation module switch, sampling module switch, and grounding switch of this detection unit.
[0007] The aforementioned DIP switch module has twelve stationary contacts, which are respectively connected to twelve I / O ports of the main control CPU. By controlling the selection knob to ground one of the stationary contacts, the voltage level of the connected I / O port changes from high to low, while the other I / O ports remain high. The selection knob has twelve positions, each corresponding to one of the twelve stationary contacts of the DIP switch module. Rotating the selection knob switches the grounding of the corresponding stationary contact of the DIP switch module.
[0008] The communication module is used for communication between the detection unit and the central control platform, as well as with other detection units.
[0009] The excitation module and sampling module mentioned are the excitation module and sampling module in existing frequency response testers.
[0010] The excitation module executes instructions from the main control CPU to generate a frequency sweep signal, and the signal output terminal of the excitation module is connected to the detection port through the excitation module switch.
[0011] The sampling module executes instructions from the main control CPU to sample voltage signals. The signal input terminal of the sampling module is connected to the detection port through the sampling module switch and grounded through a matching resistor and a grounding switch.
[0012] The detection port is connected to the clamping device.
[0013] Furthermore, the clamping device includes a fixed arm and a clamping head corresponding to the fixed arm. The handle is connected to the screw, and the clamping head is fixedly connected to the end of the screw. The clamping head is controlled to move closer to or away from the fixed arm by rotating the handle.
[0014] Furthermore, the DIP switch module includes a code disk and a conductive strip. One end of the conductive strip is fixedly connected to and grounded to a conductive shaft located at the center of the code disk. The selection knob is connected to the conductive shaft to control its rotation. The other end of the conductive strip serves as a moving contact. Twelve stationary contacts are set on the same circumference of the code disk. These twelve stationary contacts correspond to eleven phases of the high, medium, and low voltage windings, as well as one spare phase. The main control CPU reads the level status of each I / O port, identifies the winding identity, and generates a corresponding status code. If a stationary contact corresponding to a winding phase fails, the stationary contact of the spare phase is activated.
[0015] Furthermore, the general-purpose power transformer winding deformation frequency response detection unit serves as an excitation unit, a response unit, or a floating unit. The main control CPU switches between the three states by controlling the closing and opening of the excitation module switch, the sampling module switch, and the grounding switch: when the excitation module switch and the sampling module switch are closed and the grounding switch is open, the detection unit is an excitation unit; when the excitation module switch is open and the sampling module switch and the grounding switch are closed, the detection unit is a response unit; when the excitation module switch and the sampling module switch are open and the grounding switch is closed, the detection unit is a floating unit.
[0016] Furthermore, the excitation module switch is a relay or an IGBT switch. When the excitation module sends a frequency sweep signal, the excitation module switch is closed, and it is open at other times. The sampling module switch is a relay or an IGBT switch. When the sampling module performs sampling, the sampling module switch is closed, and it is open at other times.
[0017] The physical DIP switches in the detection unit of this invention avoid manual input errors. The detection unit can be flexibly deployed, automatically identifies phases, and does not require differentiation of specific units during production and installation. Only the electrical position of the corresponding bushing needs to be set after installation. It is also compatible with existing frequency response testing systems without requiring modification of the winding interface. Simultaneously, the detection unit's DIP switch panel has spare pin codes. When one of the pins corresponding to the winding phase code on the DIP switch panel fails, a spare pin can be used, reducing the risk of test failure, extending the service life of the detection unit, saving costs, and improving testing efficiency. This invention solves the problems of repetitive manual wiring operations, low testing efficiency, and susceptibility to errors in traditional transformer winding frequency response analysis (FRA) methods. It improves testing efficiency and safety, reduces testing costs, and enables remote testing. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal module structure of the detection unit; Figure 3 This is a schematic diagram of the DIP switch module structure. Detailed Implementation
[0019] like Figure 1 As shown, the general-purpose power transformer winding deformation frequency response detection unit includes a detection unit body 1 and a clamping device 2. The clamping device 2 is fixedly installed below the detection unit body 1. The clamping device 2 includes a fixed arm 21 and a clamping head 22 corresponding to the fixed arm. A handle 23 is connected to a screw 24. The clamping head 22 is fixedly connected to the end of the screw 24. By rotating the handle 23, the clamping head 22 is controlled to move closer to or away from the fixed arm 21.
[0020] The outer casing of the detection unit body 1 is equipped with a selection knob 3 and a unit power switch 4. The unit power switch 4 controls the power supply of the detection unit body 1 to be turned on and off.
[0021] like Figure 2 As shown, the detection unit body 1 includes a main control CPU 11, a communication module 12, an excitation module 13, a sampling module 14, a DIP switch module 15, an excitation module switch K1, a sampling module switch K2, a grounding switch K3, and a detection port 16. The communication module 12, excitation module 13, and sampling module 14 are connected to the main control CPU 11. The main control CPU receives instructions from the centralized control platform and controls the excitation module 13, sampling module 14, excitation module switch K1, sampling module switch K2, and grounding switch K3 of this detection unit.
[0022] like Figure 3 As shown, the DIP switch module 15 includes a code disk 151 and a conductive strip 152. One end of the conductive strip 152 is fixedly connected to and grounded to a conductive shaft 153 located at the center of the code disk 151. The selection knob 3 is connected to the conductive shaft 153 to control the rotation of the conductive shaft 153. The other end of the conductive strip 152 serves as a moving contact. Twelve stationary contacts 154 are arranged on the same circumference of the code disk 151. The twelve stationary contacts 154 are respectively connected to the twelve I / O ports of the main control CPU 11. The twelve stationary contacts correspond to eleven phases of the high, medium, and low voltage windings (phases A, B, C, and N of the high voltage winding; phases Am, Bm, Cm, and Nm of the medium voltage winding; and phases a, b, and c of the low voltage winding), as well as one spare phase (phase n). Rotating selection knob 3 causes the moving contact to connect to a stationary contact, establishing a ground connection. The corresponding I / O port level of the main control CPU then changes from high to low, while other stationary contacts remain high. The main control CPU reads the I / O port level status, identifies the winding, and generates a corresponding status code (high level = 1, low level = 0, encoded according to the stationary contact number). If a stationary contact corresponding to a winding phase fails, a spare stationary contact is used to replace the faulty phase pin.
[0023] The communication module 12 is used for communication between the detection unit and the central control platform, as well as with other detection units.
[0024] Excitation module 13 and sampling module 14 are the same as the excitation module and sampling module in the existing frequency response tester.
[0025] The excitation module executes instructions from the main control CPU 11 to generate a frequency sweep signal. The signal output terminal of the excitation module 13 is connected to the detection port 16 through the excitation module switch K1. The excitation module switch K1 is a relay or IGBT switch. When the excitation module sends a frequency sweep signal, the excitation module switch K1 is closed; otherwise, it is open.
[0026] The sampling module 14 executes instructions from the main control CPU to sample the voltage signal. The signal input terminal of the sampling module is connected to the detection port 16 through the sampling module switch K2, and grounded through the matching resistor R and the grounding switch K3. The sampling module switch K2 is a relay or IGBT switch. When the sampling module is sampling, the sampling module switch K2 is closed, and it is open at other times.
[0027] The detection port 16 is connected to the clamping device 2.
[0028] During testing, a testing unit is installed on the output terminal of each winding of the transformer under test. For transformers where the bushing leads cannot be removed, the testing unit is placed on the end tap of the bushing (the clamping device is clamped on the output terminal or the end tap and connected). Rotate the selection knob 3 to make the moving contact of each testing unit contact the corresponding stationary contact of the phase to conduct electricity.
[0029] Upon power-up, the main control CPU of each detection unit reads the I / O port level status, identifies the winding identity, and generates and stores a status code. Each detection unit can act as an excitation unit to emit signals or as a response unit to acquire signals. All detection units are connected to the centralized control platform via network communication, and there is also network communication between the detection units. The casing of all detection units is grounded.
[0030] Each detection unit can function as an excitation unit, a response unit, or a floating unit. The main control CPU switches between these three types of units by controlling the closing and opening of the excitation module switch K1, the sampling module switch K2, and the grounding switch K3: when the excitation module switch K1 and the sampling module switch K2 are closed and the grounding switch K3 is open, it is an excitation unit; when the excitation module switch K1 is open and the sampling module switch K2 and the grounding switch K3 are closed, it is a response unit; and when the excitation module switch K1 and the sampling module switch K2 are open and the grounding switch K3 is closed, it is a floating unit.
[0031] The excitation module sends a sweep frequency signal to the transformer winding under test; the sampling module acquires the voltage signal under the frequency response; the communication modules of each detection unit form a network, responsible for the network communication connection with the main control CPU of each detection unit and the network communication between each detection unit; the main control CPU executes the signals received by the communication modules. Excitation module switch K1 controls whether the excitation module's sweep frequency signal is connected to the detection port; sampling module switch K2 controls whether the voltage signal detected by the detection port is connected to the sampling module; grounding switch K3 controls whether the sampling module circuit is grounded through a 50Ω matching resistor.
[0032] The main control CPU performs a logarithmic division operation on the excitation voltage amplitude Uin(f) and the acquisition response voltage amplitude Uout(f) fed back by the excitation module and the sampling module at the same frequency to generate the amplitude ratio, thereby obtaining the amplitude-frequency response analysis data of the corresponding winding at a specific frequency. Finally, the amplitude-frequency response analysis data is bound to the corresponding phase status code and sent to the centralized control platform through the communication module.
[0033] The centralized control platform controls and processes data during the testing process. It has the function of setting the detection unit to either an "excitation unit" or a "response unit." The detection unit of any winding can be set to any state according to the test requirements. The centralized control platform sends a signal indicating whether the tested detection unit is an excitation unit or a response unit to the communication module of the designated detection unit. Simultaneously, the centralized control platform has a "one-click measurement" function, which allows setting a test scheme for the deformation frequency response of the tested winding. This involves defining the first and last leads of a winding as the excitation and response ends, respectively, and measuring the reference voltage of the excitation unit at the first end and the response voltage of the response unit at the last end of the tested winding to complete the frequency response test of one winding. The centralized control platform can also set a configurable fully automatic testing scheme according to the connection method of the transformer under test. This involves defining the first and last leads of all windings as excitation and response units, respectively, and sequentially measuring the reference voltage of the excitation unit at the first end and the response voltage of the response unit at the last end of all tested windings, thereby achieving automatic detection of the frequency response of all transformer windings.
Claims
1. A general-purpose power transformer winding deformation frequency response detection unit, characterized in that: It includes a detection unit body and a clamping device. The clamping device is fixedly installed below the detection unit body. The detection unit body is installed on the output terminal or end screen tap of each winding of the transformer under test through the clamping device. The outer casing of the detection unit body is equipped with a selection knob and a unit power switch, which controls the power supply of the detection unit body to be turned on and off. Inside the outer casing of the detection unit body are a main control CPU, a communication module, an excitation module, a sampling module, a DIP switch, an excitation module switch, a sampling module switch, a grounding switch, and a detection port. The communication module, excitation module, and sampling module are connected to the main control CPU. The main control CPU is used to receive instructions from the centralized control platform and control the excitation module, sampling module, excitation module switch, sampling module switch, and grounding switch of this detection unit. The DIP switch module has twelve stationary contacts, which are connected to twelve I / O ports of the main control CPU. By controlling the selection knob to ground one of the stationary contacts, the voltage level of the connected I / O port changes from high to low, while the other I / O ports remain high. The selection knob has twelve positions, each corresponding to one of the twelve stationary contacts of the DIP switch module. Rotating the selection knob switches the grounding of the corresponding stationary contact of the DIP switch module. The communication module is used for communication between the detection unit and the centralized control platform, as well as with other detection units; The excitation module and sampling module mentioned are the excitation module and sampling module in existing frequency response testers; The excitation module executes instructions from the main control CPU to generate a frequency sweep signal, and the signal output terminal of the excitation module is connected to the detection port through the excitation module switch; The sampling module executes instructions from the main control CPU to sample voltage signals. The signal input terminal of the sampling module is connected to the detection port through the sampling module switch and grounded through a matching resistor and a grounding switch. The detection port is connected to the clamping device.
2. The general-purpose power transformer winding deformation frequency response detection unit as described in claim 1, characterized in that: The clamping device includes a fixed arm and a clamping head corresponding to the fixed arm. The handle is connected to the screw, and the clamping head is fixedly connected to the end of the screw. The clamping head is controlled to move closer to or away from the fixed arm by rotating the handle.
3. The general-purpose power transformer winding deformation frequency response detection unit as described in claim 1, characterized in that: The aforementioned DIP switch module includes a code disk and a conductive strip. One end of the conductive strip is fixedly connected to and grounded to a conductive shaft located at the center of the code disk. The selection knob is connected to the conductive shaft to control its rotation. The other end of the conductive strip serves as a moving contact. Twelve stationary contacts are set on the same circumference of the code disk, corresponding to eleven phases of the high, medium, and low voltage windings, as well as one spare phase. The main control CPU reads the level status of each I / O port, identifies the winding identity, and generates a corresponding status code. If a stationary contact corresponding to a winding phase fails, the stationary contact of the spare phase is activated.
4. The general-purpose power transformer winding deformation frequency response detection unit as described in claim 1, characterized in that: The general-purpose power transformer winding deformation frequency response detection unit serves as an excitation unit, a response unit, or a floating unit. The main control CPU switches between these three states by controlling the closing and opening of the excitation module switch, the sampling module switch, and the grounding switch: when the excitation module switch and the sampling module switch are closed and the grounding switch is open, the detection unit is an excitation unit; when the excitation module switch is open and the sampling module switch and the grounding switch are closed, the detection unit is a response unit; when the excitation module switch and the sampling module switch are open and the grounding switch is closed, the detection unit is a floating unit.
5. The general-purpose power transformer winding deformation frequency response detection unit as described in claim 1, characterized in that: The excitation module switch is a relay or an IGBT switch. When the excitation module sends a frequency sweep signal, the excitation module switch is closed, and it is open at other times. The sampling module switch is a relay or an IGBT switch. When the sampling module performs sampling, the sampling module switch is closed, and it is open at other times.