A rotor winding inter-turn fault location detection system

Abstract

The utility model relates to circuit fault detection technical field especially a kind of rotor winding interturn fault positioning detection system. Current detection module is accessed stator winding outlet terminal and neutral point branch, provides current signal acquisition;Collection transmission module receives current detection module input signal, ensures that data transmission is reliable and efficient;Input fault processing module receives the current signal output by collection transmission module, provides filtering calculation judgment processing. The flexible configuration of the optical current transformer of the utility model at the neutral point branch of stator winding, breaks through the bottleneck that traditional electromagnetic type mutual inductor cannot be comprehensively covered by space limitation, supports the independent monitoring of multiple branches, satisfies the optimization monitoring demand of quantitative fault analysis. Stator winding outlet terminal retains electromagnetic type current transformer, combined with the optical current transformer at the neutral point branch, optimizes system configuration, the insulation skeleton design of primary sensing unit adapts different conductor size, simplifies installation and maintenance process.

Description

Technical Field

[0001] This utility model relates to the field of circuit fault detection technology, and in particular to a rotor winding inter-turn fault location and detection system. Background Technology

[0002] In existing technologies, rotor winding inter-turn fault monitoring systems typically employ electromagnetic current transformers, which are installed at the stator winding output terminals and neutral point branch groups of the generator, respectively. By measuring the unbalanced fractional fault characteristic currents such as 1 / P and 2 / P in the stator winding branch circulating current (P is the number of generator pole pairs), and combining this with rotor inter-turn fault identification criteria, fault detection is achieved, triggering alarms or tripping.

[0003] However, traditional solutions have many shortcomings. Hydroelectric generator sets have a large number of branches, and due to limitations in installation space and branch spacing, all branches are typically divided into two or three groups, with electromagnetic current transformers installed on each branch group. It's not feasible to flexibly install electromagnetic current transformers on every branch current; usually, branches can only be grouped, and transformers installed on a few branch groups. This configuration limits the flexibility and coverage of the monitoring system, failing to meet the requirements for optimal monitoring based on quantitative internal fault analysis. This results in insufficient fault detection accuracy and sensitivity, making it difficult to comprehensively capture potential inter-turn short-circuit faults.

[0004] Therefore, there is a need for a rotor winding turn-to-turn fault location and detection system that can achieve flexible configuration, overcome space limitations, improve measurement accuracy and reliability, reduce modification and maintenance costs, and improve system accuracy and stability to meet actual field needs. Utility Model Content

[0005] The purpose of this section is to outline some aspects of the embodiments of this utility model and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of this section, the abstract and the title of this utility model. Such simplifications or omissions shall not be used to limit the scope of this utility model.

[0006] Given that the existing technology has a large number of branches in the hydro-generator unit, and is limited by the installation space and branch spacing, it is not possible to flexibly install electromagnetic current transformers in each branch current, resulting in insufficient fault detection accuracy and sensitivity, and making it difficult to fully capture potential inter-turn short circuit faults.

[0007] Therefore, the technical problem to be solved by this utility model is to design a rotor winding inter-turn fault location and detection system that can achieve flexible configuration, solve space limitations, improve measurement accuracy and reliability, reduce modification and maintenance costs, and improve system accuracy and stability to meet actual field needs.

[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a terminal voltage transformer circuit, comprising,

[0009] The current detection module is connected to the stator winding output terminal and the neutral point branch respectively, providing current signal acquisition and input to the data acquisition and transmission module;

[0010] The data acquisition and transmission module receives input signals from the current detection module and inputs them into the fault processing module to ensure reliable and efficient data transmission.

[0011] The input fault handling module receives the current signal output by the acquisition and transmission module, provides filtering, calculation, judgment, and processing, and then applies a delay to the signal alarm to ensure the safe operation of the generator set.

[0012] As an improvement to this utility model

[0013] The current detection module includes an electromagnetic current transformer unit and an optical current transformer unit.

[0014] An electromagnetic current inductor unit is installed at the output end of the stator winding to measure the current signal at the output end.

[0015] An optical current inductor unit is installed at the neutral point branch of the stator winding to measure the current signal at the neutral point branch.

[0016] As an improvement to this utility model

[0017] The optical current transformer unit includes a data acquisition subunit, a transmission subunit, and a primary sensing subunit;

[0018] The output of the acquisition subunit is connected to the fiber optic digital interface in the acquisition and transmission module.

[0019] The transmission subunit provides the electrical connection between the acquisition subunit and the primary sensing subunit;

[0020] A primary sensing sub-unit is installed outside each phase conductor of the neutral point branch of the stator winding to provide corresponding current signal measurement.

[0021] As an improvement to this utility model

[0022] An insulating frame and sensing optical fiber are installed inside the primary sensing subunit;

[0023] An insulating frame ring is fitted around the outside of each phase conductor of the stator winding neutral point branch, providing support and protection;

[0024] The sensing fiber is coiled around the outer wall of the insulating frame to form a concentric fiber loop, ensuring the spatial consistency of the fiber loop and the stability of signal transmission.

[0025] As an improvement to this utility model

[0026] The first and last ends of the primary sensing subunit are connected to fiber optic fasteners to ensure that the first and last ends coincide in spatial position.

[0027] A waveplate is fixedly installed inside the optical fiber fixing component to regulate the polarization state of the optical signal;

[0028] A reflector is fixedly installed on one side of the waveplate to reflect the optical signal transmitted by the sensing fiber back to the acquisition subunit;

[0029] The interface end of the fiber optic fixing component is connected to the transmission subunit.

[0030] As an improvement to this utility model

[0031] The acquisition subunit is equipped with a light source, a coupler, and a phase modulator.

[0032] The light source generates the required optical signal, which enters the coupler after ensuring low attenuation and high signal-to-noise ratio.

[0033] The coupler is placed between the light source and the phase modulator to input the optical signal generated at the light source into the phase modulator.

[0034] As an improvement to this utility model

[0035] One end of the photodetector is connected to the coupler, and the other end is connected to the demodulation electronics.

[0036] The photodetector receives the optical signal transmitted by the coupler and converts it into an electrical signal, which is then output to the demodulation electronics.

[0037] The demodulation electronic terminal output is electrically connected to the phase modulator, and a modulation signal is applied to the phase modulator and demodulation operation is performed.

[0038] As an improvement to this utility model

[0039] The data acquisition and transmission module includes a hard-wired current input interface;

[0040] The hard-wired current input interface and the electromagnetic current transformer unit are connected via a shielded cable.

[0041] The input fault handling module is equipped with a filtering calculation unit, which is connected to the acquisition and transmission module to receive and process the signals transmitted by the acquisition and transmission module.

[0042] As an improvement to this utility model

[0043] The filtering calculation unit is connected to the detection and judgment unit;

[0044] The detection and judgment unit receives the data calculated by the filtering and calculation unit, analyzes and identifies the fault, and triggers a delayed alarm action.

[0045] The beneficial effects of this utility model are as follows: The flexible configuration of the optical current transformer at the neutral point branch of the generator stator winding breaks through the bottleneck of the traditional electromagnetic current transformer being unable to fully cover due to space limitations. It supports independent monitoring of multiple branches, meets the optimized monitoring requirements for quantitative fault analysis, retains the electromagnetic current transformer at the stator winding output end, and combines it with the optical current transformer at the neutral point branch to optimize the system configuration, reduce the workload of on-site engineering modification and sensor replacement costs, and at the same time, the insulation frame design of the primary sensing unit is adapted to different conductor sizes, simplifying the installation and maintenance process. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0047] Figure 1 This is a schematic diagram of the architecture of the rotor winding inter-turn fault location and detection system of this utility model.

[0048] Figure 2 This is a diagram showing the internal architecture of the optical current inductance unit in this invention. Detailed Implementation

[0049] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0050] Example 1

[0051] Reference Figure 1 This embodiment provides a rotor winding inter-turn fault location and detection system.

[0052] The current detection module 1 employs two complementary current measurement technologies, which are deployed at the stator winding output terminals and the neutral point branch of the generator, respectively, to achieve comprehensive current signal acquisition.

[0053] The first step is current detection at the output terminals. Electromagnetic current transformers are installed on the three-phase conductors (phase A, phase B, and phase C) at the output terminals of the stator windings. Utilizing the principle of electromagnetic induction, the phase current at the output terminals is measured. The electromagnetic current transformers in this design use high-permeability iron core materials, possessing anti-electromagnetic interference capabilities and stable signal output characteristics, making them suitable for installation environments with ample space at the output terminals.

[0054] The neutral point branch current detection and the outgoing terminal current detection work together. Optical current transformers are deployed on the three-phase conductors of the neutral point branch to achieve current measurement using the Faraday effect. The compact design of the optical current transformer allows it to fit into the limited installation space at the neutral point branch and supports flexible configuration on multiple branches, overcoming the space limitations of traditional electromagnetic current transformers.

[0055] The data acquisition and transmission module 2 is the data hub of the system, responsible for receiving the input signals from the current detection module 1 and efficiently transmitting them to the fault handling module 3. The data acquisition and transmission module 2 has interfaces for both outgoing line current detection and neutral point branch current detection, and performs necessary signal integration and synchronization processing. Through analog-to-digital conversion and clock synchronization technology, the two signals are integrated into a unified format and sent to the fault handling module 3.

[0056] The acquisition and transmission module 2 optimizes the signal transmission path through modular design and standardized interface protocols, reducing signal delay and distortion, and ensuring high-fidelity data transmission.

[0057] The fault processing module 3 is the core analysis unit of the system, responsible for processing the current signal output by the acquisition and transmission module and diagnosing faults. Module 3 can analyze the unbalanced fractional fault characteristic currents (such as 1 / P, 2 / P, where P is the number of generator pole pairs) in the stator winding branch circulating current, and calculate and separate the fault signal from background noise, improving signal purity and analysis reliability. Subsequently, it uses rotor inter-turn fault identification criteria to achieve rotor winding inter-turn short-circuit fault detection. After providing filtering, calculation, and judgment processing, module 3 applies a delay before triggering the alarm signal.

[0058] In actual installation, electromagnetic current transformers are fixed on the three-phase conductors at the stator winding output terminals. Standardized mounting clamps and bolts are used to ensure reliable contact between the transformers and the conductors. The output terminals are connected to the corresponding interface of the data acquisition and transmission module 2 via shielded cables. Optical current transformers are installed on the three-phase conductors at the neutral point branch. An insulating frame is fitted around the conductor, and optical fibers are precisely coiled to form concentric fiber loops. The fixing device ensures that the beginning and end of the optical fibers coincide. The output terminals of the optical current transformers are connected to the corresponding interface of the data acquisition and transmission module 2.

[0059] The data acquisition and transmission module 2 is installed inside the control cabinet. Hardwiring and fiber optic interface connections are completed to ensure shielding and grounding protection of the signal transmission channel. Module parameters are configured to match the generator's operating characteristics. The fault handling module is installed in the control room or a safe area next to the generator, connected to the output interface of the data acquisition and transmission module, to complete system initialization and calibration, and to set alarm thresholds and delay parameters.

[0060] During system operation, the current detection module 1 collects current signals from the outgoing terminals and neutral point branches in real time, integrates them through the acquisition and transmission module 2, and transmits them to the fault processing module 3. The fault processing module 3 performs noise reduction and feature extraction on the signals, analyzes the presence of inter-turn short circuit faults based on the feature signals, and triggers alarms or trips when necessary to ensure the safe operation of the generator set.

[0061] Example 2

[0062] Reference Figures 1-2 This embodiment is based on the previous embodiment, and differs from the previous embodiment in that:

[0063] The current detection module 1 is the core of the system's signal acquisition. It consists of an electromagnetic current transformer unit 11 and an optical current transformer unit 12, which are deployed at the stator winding output terminal and the neutral point branch of the generator, respectively, to achieve comprehensive current signal measurement.

[0064] The electromagnetic current transformer unit 11 is installed on the three-phase conductors (phase A, phase B, and phase C) at the stator winding output terminals. It employs a high-permeability iron core and precision winding design, utilizing the principle of electromagnetic induction to measure the three-phase current signals at the output terminals. The electromagnetic current transformer unit 11 possesses high anti-electromagnetic interference capability and stable signal output characteristics, making it suitable for installation environments with ample space at the output terminals, ensuring the reliability and accuracy of current measurement. The optical current transformer unit 12 includes a data acquisition subunit 121, a transmission subunit 122, and a primary sensing subunit 123.

[0065] The output of the acquisition subunit 121 is connected to the fiber optic digital interface 21 in the acquisition and transmission module 2. The acquisition subunit 121 internally includes a light source 1211, a coupler 1212, and a phase modulator 1213. The light source 1211 is used to generate an optical signal that meets the requirements, ensuring low attenuation and a high signal-to-noise ratio.

[0066] The transmission subunit 122 uses high-strength, low-loss optical fiber material to provide an optical signal transmission channel between the acquisition subunit 121 and the primary sensing subunit 123. It has tensile strength and high temperature resistance characteristics to ensure the stability of signal transmission and the ability to resist electromagnetic interference.

[0067] Coupler 1212 is positioned between light source 1211 and phase modulator 1213, enabling efficient transmission of optical signals to phase modulator 1213 and receiving returned optical signals. Phase modulator 1213 optimizes the sensitivity of optical signals and avoids low-frequency noise interference through precise optical modulation technology. Photodetector 125 is connected to coupler 1212 at one end and demodulation electronics 126 at the other end. The function of photodetector 125 is to connect to coupler 1212, convert the returned optical signal into an electrical signal, and send it to demodulation electronics 126. Demodulation electronics 1231 is electrically connected to phase modulator 1213, applies a modulation signal, performs demodulation operations, and outputs the phase current signal of the neutral point branch.

[0068] A primary sensing subunit 123 is fitted around the outside of each phase conductor of the neutral point branch of the stator winding, providing corresponding current signal measurement. The primary sensing subunit 123 includes an insulating frame 1231, a sensing optical fiber 1232, an optical fiber fixing component 124, a waveplate 1241, and a reflector 1242. The insulating frame 1231 is made of high-temperature resistant and high-strength insulating material and is fitted around the outside of the three phase conductors of the neutral point branch, providing mechanical support and electrical isolation for the sensing optical fiber.

[0069] The sensing fiber 1232 is coiled around the outer wall of the insulating frame to form a concentric fiber loop. It senses changes in the magnetic field around the conductor and generates a phase difference in the optical signal, ensuring the spatial consistency of the fiber loop and the stability of signal transmission. The fiber fixing component 124 fixes the beginning and end of the sensing fiber to ensure that the spatial positions coincide. The waveplate 1241 regulates the polarization state of the optical signal and optimizes the measurement accuracy. The reflector 1242 uses a high-reflectivity optical material to reflect the optical signal back to the acquisition subunit 121, improving the signal utilization efficiency.

[0070] In this scheme, a primary sensing subunit 123 is installed on the selected neutral point branch three-phase conductor, an insulating frame 1231 is looped around the conductor, and a sensing optical fiber 1232 is precisely coiled and fixed by an optical fiber fastener 124; the acquisition subunit 121 is fixed in a safe area near the generator, and is connected to the primary sensing subunit 123 through the transmission subunit 122, and the output end is connected to the optical fiber digital interface of the acquisition and transmission module 2.

[0071] The acquisition and transmission module 2 includes a hard-wired current input interface 22, which is connected to the electromagnetic current transformer unit 11 via a shielded cable to receive the analog current signal from the output end. It adopts a high impedance design and electromagnetic shielding technology to ensure low signal attenuation and high anti-interference capability.

[0072] The fiber optic digital interface 21 in the acquisition and transmission module 2 is connected to the acquisition subunit 121 of the optical current transformer unit 12 to receive the digital current signal of the neutral point branch. By utilizing the high bandwidth and anti-electromagnetic interference characteristics of fiber optic transmission, the efficiency and reliability of signal transmission are guaranteed.

[0073] The acquisition and transmission module 2 contains a signal integration function area, which synchronously processes the digital signals of the fiber optic digital interface 21 and the hard-wired current input interface 22, integrating the two types of signals into a unified format, supporting real-time data acquisition and fast transmission, and adapting to the dynamic operating conditions of the generator.

[0074] Example 3

[0075] Reference Figures 1-2 This embodiment is based on the previous embodiment, and differs from the previous embodiment in that:

[0076] The fault handling module 3 is the core of the data processing and decision-making of the inter-turn fault monitoring system for the rotor winding of the hydro generator. The filtering and calculation unit 31 is responsible for denoising and feature extraction of the current signal transmitted by the acquisition and transmission module, generating high-quality data for fault analysis. The detection and judgment unit 311 receives the processing results of the filtering and calculation unit 31, executes the fault identification algorithm, analyzes and locates the inter-turn short-circuit fault of the rotor winding, and triggers a delayed alarm action.

[0077] The fault handling module 3 adopts a high-performance embedded processor and modular hardware design, and is equipped with an electromagnetic interference-resistant shielded housing and high-temperature resistant circuit components to ensure stable operation under complex operating conditions of the hydro-generator.

[0078] The filtering calculation unit 31 receives the current signal transmitted by the acquisition and transmission module 2, including the current signals from the stator winding output terminals and the neutral point branch. It uses a multi-level digital filtering algorithm to remove environmental noise, electromagnetic interference, and high-frequency harmonics, ensuring signal purity. The filtering algorithm supports dynamic parameter adjustment, optimizing the filtering effect according to the generator's operating status. The filtering calculation unit 31 performs frequency and time domain analysis on the filtered current signal, extracting the unbalanced fractional fault characteristic currents (such as 1 / P, 2 / P, where P is the number of generator pole pairs) from the circulating current in the stator winding branch. This accurately separates the fault characteristic signal from the background signal, providing high-quality input for subsequent fault diagnosis.

[0079] The detection and judgment unit 311 is the decision-making core of the fault handling module. It receives the feature data calculated by the filtering and calculation unit 31, executes the fault identification and location algorithm, and triggers the corresponding protection action.

[0080] The detection and judgment unit 311 can analyze the characteristic data and accurately identify the short circuit fault between the rotor winding turns. The detection and judgment unit 311 focuses on analyzing the amplitude, phase and spectrum characteristics of the characteristic current of the unbalanced fractional fault, and combines it with the generator's operating status, such as excitation current, rotor vibration or reactive power output, to make a comprehensive judgment and determine the existence and severity of the fault.

[0081] By comparing the current signal characteristics of different neutral point branches, the detection and judgment unit 311 can locate the specific branch or winding segment where the fault occurs, thereby improving the pertinence of fault diagnosis and maintenance efficiency.

[0082] Based on the severity of the fault and the preset protection strategy, the detection and judgment unit 311 triggers a signal alarm or trips after a delay. The delay mechanism is implemented through a programmable logic controller, which supports dynamic adjustment of the delay parameters to avoid false alarms caused by transient interference, while ensuring timely response to persistent faults.

[0083] The fault handling module 3 is installed in a safe area next to the control room or generator. It adopts a standard rack-mount design for easy integration into existing monitoring systems. The input of the filter calculation unit 31 is connected to the output of the acquisition and transmission module via a high-speed data interface, ensuring stable signal transmission and low latency. The detection and judgment unit 311 is integrated with the filter calculation unit 31 via an internal bus, requiring no additional wiring.

[0084] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A rotor winding inter-turn fault location and detection system, characterized in that: include. The current detection module (1) is connected to the stator winding output terminal and the neutral point branch respectively, providing current signal acquisition to the data acquisition and transmission module (2); The data acquisition and transmission module (2) receives the input signal from the current detection module (1) and inputs the fault processing module (3) to ensure reliable and efficient data transmission. The input fault processing module (3) receives the current signal output by the acquisition and transmission module (2), provides filtering, calculation, judgment, and processing, and then applies a delay to the signal alarm to ensure the safe operation of the generator set.

2. The rotor winding inter-turn fault location and detection system as described in claim 1, characterized in that: The current detection module (1) includes an electromagnetic current transformer unit (11) and an optical current transformer unit (12); An electromagnetic current transformer unit (11) is installed at the output end of the stator winding to measure the current signal at the output end; An optical current transformer unit (12) is set in the neutral point branch of the stator winding to measure the current signal of the neutral point branch.

3. The rotor winding inter-turn fault location and detection system as described in claim 2, characterized in that: The optical current transformer unit (12) includes a data acquisition subunit (121), a transmission subunit (122), and a primary sensing subunit (123); The output of the acquisition subunit (121) is connected to the fiber optic digital interface (21) in the acquisition and transmission module (2); The transmission subunit (122) provides an electrical connection between the acquisition subunit (121) and the primary sensing subunit (123); A primary sensing subunit (123) is mounted outside each phase conductor of the neutral point branch of the stator winding to provide corresponding current signal measurement.

4. The rotor winding inter-turn fault location and detection system as described in claim 3, characterized in that: An insulating frame (1231) and a sensing fiber (1232) are provided inside the primary sensing subunit (123); The insulating frame (1231) ring is fitted around the outside of each phase conductor of the stator winding neutral point branch, providing support and protection; The sensing fiber (1232) is coiled around the outer wall of the insulating frame (1231) to form a concentric fiber ring, ensuring the spatial consistency of the fiber ring and the stability of signal transmission.

5. The rotor winding inter-turn fault location and detection system as described in claim 3, characterized in that: The first and last ends of the primary sensing subunit (123) are connected to the optical fiber fixing piece (124) to ensure that the first and last ends coincide in spatial position; A waveplate (1241) is fixedly installed inside the optical fiber fixing component (124) to regulate the polarization state of the optical signal; A reflector (1242) is fixedly installed on one side of the waveplate (1241) to reflect the light signal transmitted by the sensing fiber (1212) back to the acquisition subunit (121); The interface end of the fiber optic fastener (124) is connected to the transmission subunit (122).

6. The rotor winding inter-turn fault location and detection system as described in any one of claims 3 to 5, characterized in that: The acquisition subunit (121) is equipped with a light source end (1211), a coupler (1212) and a phase modulator (1213); The light source (1211) generates the required optical signal, and after ensuring low attenuation and high signal-to-noise ratio, it enters the coupler (1212); A coupler (1212) is placed between the light source end (1211) and the phase modulator (1213) to input the optical signal generated by the light source end (1211) into the phase modulator (1213); 7. The rotor winding inter-turn fault location and detection system as described in claim 6, characterized in that: One end of the photodetector (125) is connected to the coupler (1212), and the other end is connected to the demodulation electronics terminal (126); The photodetector (125) receives the optical signal transmitted by the coupler (1212) and converts it into an electrical signal, which is then output to the demodulation electronics terminal (126). The output of the demodulation electronic terminal (126) is electrically connected to the phase modulator (1213), and a modulation signal is applied to the phase modulator (1213) and demodulation operation is performed.

8. The rotor winding inter-turn fault location and detection system as described in claim 7, characterized in that: The data acquisition and transmission module (2) includes a hard-wired current input interface (22); The hard-wired current input interface (22) and the electromagnetic current transformer unit (11) are connected by a shielded cable; The input fault processing module (3) is equipped with a filtering calculation unit (31), which is connected to the acquisition and transmission module (2) to receive and process the signals transmitted by the acquisition and transmission module (2).

9. The rotor winding inter-turn fault location and detection system as described in claim 8, characterized in that: The filtering calculation unit (31) is connected to the detection and judgment unit (311); The detection and judgment unit (311) receives the data calculated by the filter calculation unit (31), analyzes and identifies the fault and triggers a delayed alarm action.

Images