Grounding protection configuration device for generator rotor
By using two independent rotor grounding protection devices and a real-time data interaction system, the reliability and speed issues of generator rotor grounding protection configuration in existing technologies have been resolved, enabling stable operation of the generator set and improved economic benefits.
Patent Information
- Application Number
- CN202520311996.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-02-26
AI Technical Summary
Existing generator rotor grounding protection configurations have limited protection range, slow operating speed, and low reliability, leading to unstable power system operation. Furthermore, fault handling can cause equipment outages, reducing power plant efficiency and economic benefits.
Two independent rotor grounding protection devices are adopted, namely the first rotor grounding protection device and the second rotor grounding protection device. They are powered by independent power supplies and combine the protection DSP board and the start-up DSP board to perform real-time data interaction and self-testing, so as to realize rapid fault diagnosis and switching. They are configured as the main and backup systems and combine the dual-end or single-end injection grounding protection principle for real-time monitoring.
It improves the reliability and sensitivity of protection, reduces the impact of faults, ensures the stable operation of power plants, reduces equipment maintenance costs and power outage losses, and enhances economic benefits and operational efficiency.
Smart Images
Figure CN223942406U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of grounding protection devices, specifically a generator rotor grounding protection configuration device. Background Technology
[0002] Generators are crucial equipment in power systems, and their safe and stable operation directly affects the stability and reliability of the entire power system. Rotor grounding faults are among the most common generator faults. If these faults are not detected and addressed promptly, they can lead to winding short circuits, causing serious consequences such as unit vibration and rotor burns, severely threatening the operational safety of large generator sets.
[0003] Existing generator rotor grounding protection is a traditional single-layer protection configuration. However, the traditional single-layer protection configuration has many shortcomings, such as limited protection range, slow action speed, and low reliability. It is difficult to meet the needs of modern power systems. At the same time, the entire equipment will stop supplying power when the system is under maintenance or a fault occurs, which reduces the operating efficiency and economic benefits of the power plant and cannot guarantee the stable operation of the power plant. Therefore, we propose a generator rotor grounding protection configuration device. Utility Model Content
[0004] To address the shortcomings of existing technologies, this utility model provides a generator rotor grounding protection configuration device, which solves the problems mentioned in the background.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] A generator rotor grounding protection configuration device includes a cabinet, a demagnetizing resistor cabinet, a first grounding device power supply, a first injection device power supply, a second grounding device power supply, a second injection device power supply, a first rotor grounding protection device, and a second rotor grounding protection device.
[0007] The first rotor grounding protection device is electrically connected to the generator-transformer group protection cabinet A, and the second rotor grounding protection device is electrically connected to the generator-transformer group protection cabinet B. The power supply of the first grounding device and the power supply of the first injection device are both electrically connected to the first rotor grounding protection device, and the power supply of the second grounding device and the power supply of the second injection device are both electrically connected to the second rotor grounding protection device.
[0008] The first rotor grounding protection device and the second rotor grounding protection device are both fixedly installed inside the demagnetizing resistor cabinet. The first rotor grounding protection device and the second rotor grounding protection device 14 are electrically connected. The demagnetizing resistor cabinet is equipped with a protection DSP board and a start-up DSP board, and adopts an AND gate output method. The protection DSP board and the start-up DSP board are electrically connected.
[0009] Furthermore, the input terminals of both the protection DSP board and the startup DSP board are electrically connected to optical isolation, and both the protection DSP board and the startup DSP board are electrically connected to the CPU.
[0010] Furthermore, the cabinet also includes a cabinet body, the demagnetizing resistor cabinet is fixedly installed inside the cabinet body, and a moisture-proof board is fixedly connected to the bottom of the cabinet body.
[0011] Furthermore, a DCS alarm interface, a first reset light, and a second reset light are fixedly installed on one side of the demagnetizing resistor cabinet.
[0012] Furthermore, an iron frame is fixedly connected to the inner wall of the cabinet, and a second reset lamp is fixedly connected to the outside of the iron frame. The power supply of the first grounding device, the power supply of the first injection device, the power supply of the second grounding device, and the power supply of the second injection device are all slidably installed outside the second reset lamp.
[0013] Furthermore, both the first rotor grounding protection device and the second rotor grounding protection device adopt NARI PCS-985RE.
[0014] Beneficial effects
[0015] This utility model provides a generator rotor grounding protection configuration device. Compared with the prior art, it has the following advantages:
[0016] 1. This utility model, by setting up a first rotor grounding protection device and a second rotor grounding protection device, ensures that the power supplies of the two protection devices are independent and do not affect each other, which can greatly improve the reliability and sensitivity of the protection and effectively reduce the impact of faults on the power system.
[0017] 2. The two sets of protection equipment also help improve the economic efficiency of the power plant, reduce the probability of failure and shorten the fault handling time, while effectively improving the anti-interference capability, ensuring the accuracy of measurement and diagnosis, effectively reducing equipment maintenance costs and power outage losses, and improving the operating efficiency and economic benefits of the power plant.
[0018] 3. The two sets of protection equipment can operate two independent protection systems, one as the primary system and the other as a backup. This configuration not only improves the reliability and sensitivity of the protection, but also allows the other system to take over immediately when one system fails, ensuring the continuous and stable operation of the generator set, reducing the impact of faults on the power system, and providing strong support for the safe and stable operation of the power plant. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the main structure of this utility model;
[0020] Figure 2 This is a schematic diagram of the internal structure of the cabinet of this utility model;
[0021] Figure 3 This is a schematic diagram of one side of the demagnetizing resistor cabinet of this utility model;
[0022] Figure 4 for Figure 3 A magnified structural diagram of part A;
[0023] Figure 5 A schematic diagram showing the protection and startup sections of the DSP board.
[0024] Figure 6 This is a schematic diagram for protection.
[0025] Figure 7 This is a schematic diagram of a two-ended injection system.
[0026] Figure 8 This is a schematic diagram of the single-ended injection principle.
[0027] Figure 9 This is a schematic diagram of a single-point grounding protection for an injection-type rotor.
[0028] Figure 10 This is a schematic diagram of two-point grounding protection for an injection-type rotor.
[0029] In the diagram: 1. Screen cabinet; 2. Cabinet body; 3. Moisture-proof board; 4. Iron frame; 5. Magnetizing resistor cabinet; 6. DCS alarm interface; 7. First reset light; 8. Second reset light; 9. Power supply for the first grounding device; 10. Power supply for the first injection device; 11. Power supply for the second grounding device; 12. Power supply for the second injection device; 13. First rotor grounding protection device; 14. Second rotor grounding protection device. Detailed Implementation
[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0031] Please see Figure 1-5 This utility model provides a technical solution: a generator rotor grounding protection configuration device, including a generator rotor grounding protection configuration device, including a cabinet 1, a demagnetizing resistor cabinet 5, a first grounding device power supply 9, a first injection device power supply 10, a second grounding device power supply 11, a second injection device power supply 12, a first rotor grounding protection device 13, and a second rotor grounding protection device 14, wherein the first rotor grounding protection device 13 and the second rotor grounding protection device 14 both adopt NARI PCS-985RE;
[0032] The inner wall of the cabinet 1 is fixedly connected to an iron frame 4, and the outside of the iron frame 4 is fixedly connected to a second reset light 8. The power supply 9 of the first grounding device, the power supply 10 of the first injection device, the power supply 11 of the second grounding device, and the power supply 12 of the second injection device are all slidably installed outside the second reset light 8. The cabinet 1 also includes a cabinet body 2, and a demagnetizing resistor cabinet 5 is fixedly installed inside the cabinet body 2. A moisture-proof board 3 is fixedly connected to the bottom of the cabinet body 2. A DCS alarm interface 6, a first reset light 7, and a second reset light 8 are fixedly installed on one side of the demagnetizing resistor cabinet 5.
[0033] DCS alarm interface 6 is used to quickly identify abnormal equipment, and first reset light 7 and second reset light 8 are used to observe the working status of first rotor grounding protection device 13 and second rotor grounding protection device 14.
[0034] The first rotor grounding protection device 13 is electrically connected to the generator-transformer group protection cabinet A, and trips through the output of the generator-transformer group protection cabinet A. The second rotor grounding protection device 14 is electrically connected to the generator-transformer group protection cabinet B, and trips through the output of the generator-transformer group protection cabinet B. The first grounding device power supply 9 and the first injection device power supply 10 are both electrically connected to the first rotor grounding protection device 13. The second grounding device power supply 11 and the second injection device power supply 12 are both electrically connected to the second rotor grounding protection device 14.
[0035] The first rotor grounding protection device 13 and the second rotor grounding protection device 14 are both fixedly installed inside the demagnetizing resistor cabinet 5. The first rotor grounding protection device 13 and the second rotor grounding protection device 14 are electrically connected. The demagnetizing resistor cabinet 5 is equipped with a protection DSP board and a start-up DSP board, which are connected in an AND gate output manner. The protection DSP board and the start-up DSP board are electrically connected. The input terminals of the protection DSP board and the start-up DSP board are electrically connected to optical isolation devices. The protection DSP board and the start-up DSP board are electrically connected to CPUs.
[0036] Specifically, in the existing technology, only one set of rotor grounding protection is put into normal operation. The rotor voltage and main shaft voltage are switched by switching the switch on the cabinet. However, before switching the device, the voltage of the output pressure plate of the rotor grounding protection device to be put into operation should be measured to determine whether the device is normal and whether there is a trip output.
[0037] The specific technical principles are as follows:
[0038] The protection DSP board and the start-up DSP board each have independent sampling and output circuits. The input current and voltage are first transformed to the secondary side through existing equipment, such as isolation transformers and isolation amplifiers, and become small voltage signals before entering the protection DSP board and the start-up DSP board respectively. The protection DSP board mainly completes the protection logic and trip output functions.
[0039] The DSP board is equipped with a main startup component. After startup, it opens the positive power supply of the existing technology relay, enabling real-time data interaction between the protection DSP board and the startup DSP board. This achieves strict mutual and self-testing. If either the protection DSP board or the startup DSP board fails, the device will immediately lock and alarm, preventing false activation caused by hardware failure.
[0040] More specifically, such as Figure 6 As shown, in the prior art, the main program responds to external interrupts at a fixed cycle, and performs analog signal acquisition and filtering, digital signal acquisition, device hardware self-test, external abnormal condition check, and start-up logic calculation in the interrupt service routine. Depending on whether the start-up conditions are met, it enters the normal operation program or the fault calculation program.
[0041] However, during normal operation, the device performs a self-test. If the device malfunctions, it sends an alarm signal. There are two types of signals: one is an abnormal operation alarm, in which the device is not locked and the operator is reminded to take appropriate action; the other is a lockout alarm signal, which locks the device and disables protection at the same time.
[0042] The fault calculation program performs various protection algorithm calculations and trip logic judgments. The device's startup and protection startup DSP board or the protection DSP board independently runs their respective fault calculation programs. The device will only take action if both of them simultaneously determine that a fault has occurred.
[0043] Furthermore, depending on the lead-out method of the engine rotor winding on site, either a double-ended injection or a single-ended injection rotor grounding protection principle can be selected. The working circuits for double-ended injection and single-ended injection rotor grounding protection are as follows: Figure 7 and Figure 8 As shown;
[0044] Where Ur is the rotor voltage, α is the grounding position percentage (0% for the negative terminal and 100% for the positive terminal), Rx is the measurement circuit resistance, Ry is the injected high-power resistor, Us is the injected square wave power module, and Rg is the insulation resistance of the rotor winding to the shaft.
[0045] A low-frequency square wave voltage is injected between the positive and negative ends (or the negative end) of the rotor winding and the shaft. The rotor grounding resistance is calculated in real time to protect against the decrease in the insulation resistance of the generator rotor to the shaft. Depending on the structure, a double-ended injection type or a single-ended injection type rotor grounding protection can be selected.
[0046] Specifically, injection-type rotor grounding protection is further divided into injection-type rotor single-point grounding protection and injection-type rotor two-point grounding protection, such as... Figure 9 and Figure 10 As shown;
[0047] The injection-type rotor single-point grounding protection has two operating values: a sensitive segment and a normal segment. The sensitive segment activates an alarm, while the normal segment can activate either a signal or a trip. The alarm delay and trip delay can be set separately.
[0048] For units that can simultaneously bring out the positive and negative ends of the rotor windings, the external power supply rotor grounding protection principle can measure the grounding position at one point, and then realize the rotor two-point grounding protection by judging the change of the grounding position.
[0049] If the rotor single-point grounding protection operates in alarm mode, and the rotor grounding resistance Rg is less than the normal section setting value, after the rotor single-point grounding protection operates, it will automatically switch to rotor two-point grounding protection after a delay. When the grounding position α changes to a certain value, it will be judged as rotor two-point grounding and will trip.
[0050] Working principle: The first grounding device power supply 9 and the first injection device power supply 10 supply power to the first rotor grounding protection device 13, and the second grounding device power supply 11 and the second injection device power supply 12 supply power to the second rotor grounding protection device 14.
[0051] Meanwhile, the input current and voltage signals are converted into small voltage signals through isolation transformers and isolation amplifiers. These signals enter the protection DSP board and the start-up DSP board respectively. The protection DSP board is responsible for the calculation of protection logic and the trip output function, while the start-up DSP board is responsible for the start-up logic of the device. After start-up, the positive power supply of the output relay is turned on. The two DSP boards perform real-time data interaction to achieve strict mutual and self-testing. If one of the DSP boards fails, the device will immediately lock and alarm to prevent false operation caused by hardware failure.
[0052] If the internal equipment of the demagnetizing resistor cabinet 5 malfunctions, an alarm signal is issued. The DCS alarm interface 6 displays the equipment status in real time to quickly locate the abnormal equipment. The first reset light 7 and the second reset light 8 indicate the working status of the first rotor grounding protection device 13 and the second rotor grounding protection device 14, respectively.
[0053] The device will only execute an output action (such as tripping) if both the protection DSP board and the startup DSP board determine that a fault has occurred.
[0054] For engine rotor grounding faults, the device uses injection-type grounding protection technology to monitor the insulation resistance Rg of the rotor windings to the shaft in real time.
[0055] Single-point grounding protection: It is equipped with a sensitive section and a normal section.
[0056] Sensitive segment: Activates the alarm, used for early fault warning.
[0057] Normal section: can act on signals or trip, and the specific action mode can be set by delay.
[0058] Two-point grounding protection: When the rotor single-point grounding protection is activated, if the grounding resistance Rg is less than the normal section setting value, the device will automatically activate two-point grounding protection. If the grounding position α changes significantly (reaches a certain value), it is determined that the rotor is grounded at two points, and the device will trip.
[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0060] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A generator rotor grounding protection configuration device, characterized in that: It includes a cabinet (1), a demagnetizing resistor cabinet (5), a first grounding device power supply (9), a first injection device power supply (10), a second grounding device power supply (11), a second injection device power supply (12), a first rotor grounding protection device (13), and a second rotor grounding protection device (14). The first rotor grounding protection device (13) is electrically connected to the generator-transformer group protection cabinet A, and the second rotor grounding protection device (14) is electrically connected to the generator-transformer group protection cabinet B. The first grounding device power supply (9) and the first injection device power supply (10) are both electrically connected to the first rotor grounding protection device (13), and the second grounding device power supply (11) and the second injection device power supply (12) are both electrically connected to the second rotor grounding protection device (14). The first rotor grounding protection device (13) and the second rotor grounding protection device (14) are both fixedly installed inside the demagnetizing resistor cabinet (5). The first rotor grounding protection device (13) and the second rotor grounding protection device (14) are electrically connected. The demagnetizing resistor cabinet (5) is equipped with a protection DSP board and a start-up DSP board, and adopts an AND gate output method. The protection DSP board and the start-up DSP board are electrically connected.
2. The generator rotor grounding protection configuration device according to claim 1, characterized in that: The input terminals of both the protection DSP board and the startup DSP board are electrically connected to optical isolation, and both the protection DSP board and the startup DSP board are electrically connected to the CPU.
3. The generator rotor grounding protection configuration device according to claim 2, characterized in that: The cabinet (1) also includes a cabinet body (2), and the demagnetizing resistor cabinet (5) is fixedly installed inside the cabinet body (2). A moisture-proof board (3) is fixedly connected to the bottom of the cabinet body (2).
4. The generator rotor grounding protection configuration device according to claim 3, characterized in that: The DCS alarm interface (6), the first reset light (7), and the second reset light (8) are fixedly installed on one side of the demagnetizing resistor cabinet (5).
5. A generator rotor grounding protection configuration device according to claim 4, characterized in that: The inner wall of the cabinet (1) is fixedly connected to an iron frame (4), and the outside of the iron frame (4) is fixedly connected to a second reset lamp (8). The first grounding device power supply (9), the first injection device power supply (10), the second grounding device power supply (11) and the second injection device power supply (12) are all slidably installed outside the second reset lamp (8).
6. The generator rotor grounding protection configuration device according to claim 1, characterized in that: The first rotor grounding protection device (13) and the second rotor grounding protection device (14) both adopt NARI PCS-985RE.