An optimized matching protection system and method based on double casing synchronization device
By introducing a monitoring process for closing and blocking signals between the two sets of synchronizing devices, the risks of grid-connected circuit breaker closing and failure in the design of the two sets of synchronizing devices are resolved, ensuring the safety and stability of the power generation system.
Patent Information
- Application Number
- CN202210751499.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-29
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2042-06-29
AI Technical Summary
In the design of dual synchronizing devices, there is a risk of circuit breaker closing and failure, especially when the main synchronizing device closes successfully and external equipment fails or protection actions require the circuit breaker to trip, the backup synchronizing device may restart to close, leading to safety hazards.
By introducing a monitoring process for closing and blocking signals between the primary and backup synchronizing devices, it is ensured that the backup synchronizing device is blocked after the primary synchronizing device is successfully closed, preventing the synchronizing device from restarting in case of a fault. After the device issues a blocking command, it enters a self-blocking state and re-enters the standby state.
This effectively avoids the risk of the backup synchronizing device restarting in case of a fault, ensuring the safety and stability of the generator-transformer grid connection and preventing the synchronizing device from restarting under abnormal conditions.
Smart Images
Figure CN115036981B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of power generation synchronization closing, and relates to an optimized cooperation protection system and method based on double sets of synchronization devices. BACKGROUND
[0002] Due to the influence of factors such as load and reservoir water level, the units of a hydropower plant are started and stopped more frequently than those of a thermal power plant, so some hydropower stations are equipped with two sets of completely same synchronization devices at the synchronization point to ensure the reliability of synchronization closing. Both sets of synchronization devices have independent acquisition and outgoing control systems, can be used as one main and one backup, and can realize automatic switching function, so as to achieve the purpose of detecting and automatically starting the standby synchronization device when the main synchronization closing fails. However, in the current cooperation design of double sets of synchronization devices, there is a risk of breaker closing and fault, for example, after the main synchronization device is successfully closed, due to external equipment failure (single side without pressure) or protection action requiring the breaker to trip, the standby synchronization device needs to be locked to continue closing to prevent the standby synchronization device from starting again in the fault state. SUMMARY
[0003] The application aims to overcome the shortcomings of the prior art, and provides an optimized cooperation protection system and method based on double sets of synchronization devices, which can avoid the risk of breaker closing and fault.
[0004] To achieve the above purpose, the optimized cooperation protection system based on double sets of synchronization devices comprises a breaker, an A set of synchronization devices and a B set of synchronization devices, and the output ends of the A set of synchronization devices and the B set of synchronization devices are connected with the control end of the breaker.
[0005] One of the A set of synchronization devices and the B set of synchronization devices is used as the main synchronization device, and the other is used as the standby synchronization device.
[0006] The A set of synchronization devices and the B set of synchronization devices adopt a working mode of one standby and one use.
[0007] The optimized cooperation protection method based on double sets of synchronization devices comprises the following steps:
[0008] The A set of synchronization devices is a main synchronization device, and the B set of synchronization devices is a backup synchronization device; when the main synchronization device detects that both sides of the circuit breaker reach the synchronization condition, a closing instruction is sent; when the main synchronization device sends the closing instruction successfully, the synchronization point circuit breaker is closed; when the main synchronization device fails to send the closing instruction, the backup synchronization device is started, the backup synchronization device judges that both sides of the synchronization point circuit breaker reach the synchronization condition, and sends a closing instruction; when the backup synchronization device sends the closing instruction successfully, the synchronization point circuit breaker is closed; and when the backup synchronization device fails to send the closing instruction, the backup synchronization device enters a device locking state, and then, after a reset or a delay time, reenters the standby state.
[0009] When the synchronization point circuit breaker is successfully closed, the circuit breaker auxiliary contact is closed; when the synchronization point circuit breaker fails to be closed, the synchronization device fails to detect the closed signal of the circuit breaker auxiliary contact, and enters a device locking state, and then, after a reset or a delay time, reenters the standby state.
[0010] When the circuit breaker auxiliary contact is closed, if the main synchronization device fails to detect the closed signal of the auxiliary contact, the device enters a locking state, and then, after a reset or a delay time, reenters the standby state; if the main synchronization device collects the closed signal of the circuit breaker auxiliary contact, a closing signal is sent to the backup synchronization device; after the backup synchronization device receives the closing signal, a locking instruction is sent and a locking signal is received, and then the backup synchronization device is locked and enters a device locking state.
[0011] When the circuit breaker auxiliary contact is closed and an abnormality occurs, the protection action requires the circuit breaker to trip or an external device is faulty, and the circuit breaker trips successfully.
[0012] When the synchronization point circuit breaker fails to be closed, the synchronization device fails to detect the closed signal of the circuit breaker auxiliary contact, and the device is abnormally locked, enters a locking state, and then, after a reset or a delay time, reenters the standby state.
[0013] When the circuit breaker auxiliary contact is closed, if the main synchronization device fails to detect the closed signal of the auxiliary contact, an alarm of abnormal locking of the circuit breaker is prompted, the device enters a locking state, and then, after a reset or a delay time, reenters the standby state.
[0014] The external device fault is unilateral no pressure.
[0015] When the synchronization point circuit breaker fails to be closed, the synchronization device fails to detect the closed signal of the circuit breaker auxiliary contact within a preset time, and then enters a device locking state, and then, after a reset or a delay time, reenters the standby state.
[0016] The application has the following beneficial effects:
[0017] The optimization matching protection system and method based on the double set of synchronization devices in the application in the specific operation, respectively, the closing command signal in the monitoring process is introduced into the A set of synchronization devices and the B set of synchronization devices, when the main synchronization device has detected the circuit breaker auxiliary contact closing signal, then in the current step, the standby synchronization device is locked to prevent the standby synchronization device from continuing to close. In addition, it should be noted that the application adds a locking signal in the A set of synchronization devices and the B set of synchronization devices, after the device issues a locking instruction, the device can realize self-reception and locking, and then enter the device locking state, after resetting or time delay, re-enter the standby state, wait for subsequent inspection and operation. The receiving of the locking signal can avoid the abnormality after closing and cause the standby synchronization device to start closing again, effectively avoiding the risk of synchronization device closing under fault condition, and providing protection for the safety of generator transformer group grid connection. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 The flowchart of the application. DETAILED DESCRIPTION
[0019] In order to make the person in the art better understand the application scheme, the technical scheme in the embodiment of the application will be described clearly and completely below, combined with the drawings in the embodiment of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments, and are not intended to limit the scope of the application disclosed. In addition, in the following description, the description of the known structure and technology is omitted to avoid unnecessary confusion of the concept disclosed in the application. Based on the embodiments in the application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope of protection of the application.
[0020] The structural schematic diagram according to the disclosed embodiment of the application is shown in the drawings. These figures are not drawn to scale, in which some details are enlarged for the purpose of clear expression, and some details may be omitted. The shape of various regions, layers and their relative size and position relationship shown in the figure are only exemplary, and may deviate in actual due to manufacturing tolerance or technical limitation, and the person skilled in the art can additionally design regions / layers with different shapes, sizes and relative positions according to actual needs.
[0021] Reference Figure 1The optimization cooperation protection system based on the double-set synchronization device comprises a circuit breaker, an A-set synchronization device and a B-set synchronization device, and the output ends of the A-set synchronization device and the B-set synchronization device are connected with the control end of the circuit breaker; the A-set synchronization device and the B-set synchronization device adopt a working mode of one standby and one use, wherein one of the A-set synchronization device and the B-set synchronization device is used as a main synchronization device, and the other is used as a standby synchronization device.
[0022] The optimization cooperation protection method based on the double-set synchronization device comprises the following steps:
[0023] When the main synchronization device detects that the circuit breaker on both sides reaches the synchronization condition, a closing instruction is sent; when the main synchronization device sends the closing instruction successfully, the circuit breaker at the synchronization point is closed; when the main synchronization device fails to send the closing instruction, the standby synchronization device is started, the standby synchronization device judges that the circuit breaker on both sides at the synchronization point reaches the synchronization condition and sends a closing instruction, when the standby synchronization device sends the closing instruction successfully, the circuit breaker at the synchronization point is closed, and when the standby synchronization device fails to send the closing instruction, the standby synchronization device enters a device locking state, and then after a reset or a delay time, the standby synchronization device reenters the standby state at the beginning;
[0024] When the circuit breaker at the synchronization point is successfully closed, the auxiliary contact of the circuit breaker is closed; when the circuit breaker at the synchronization point fails to be closed, the synchronization device fails to detect the auxiliary contact closing signal of the circuit breaker, the circuit breaker is abnormally locked, a device locking state is entered, and then after a reset or a delay time, the circuit breaker reenters the standby state at the beginning;
[0025] After the auxiliary contact of the circuit breaker is closed, when the main synchronization device fails to detect the signal of the auxiliary contact closing, an alarm of the circuit breaker abnormal locking is prompted, a device locking state is entered, and then after a reset or a delay time, the circuit breaker reenters the standby state at the beginning; when the main synchronization device collects the signal of the auxiliary contact closing of the circuit breaker, a closing signal is sent to the standby synchronization device; when the standby synchronization device receives the closing signal, a locking instruction is sent and a locking signal is received, and then self-locking is performed, and a device locking state is entered;
[0026] When the auxiliary contact of the circuit breaker is abnormally closed, the protection action requires the circuit breaker to trip or an external device is faulty (for example, when there is no voltage on one side), the circuit breaker trips successfully, and the standby synchronization device has been locked to avoid starting the closing again.
[0027] In the existing grid-connected system equipped with double sets of synchronization devices, the design is originally intended to take the backup measures after the failure of single set of synchronization device closing, and the problem of blocking the standby synchronization device to continue closing when the main synchronization device closing is successful, but the external equipment fails or the protection action requires the breaker to trip is not considered. In the present application, the closing signal in the monitoring process of the main synchronization device is introduced into the standby synchronization device, and the functions of closing signal and blocking signal are added in the two sets of synchronization devices. When the program has successfully synchronized and parallel executed, the closing instruction is transmitted to the standby synchronization device in the current step, and the functions of closing instruction and blocking of the standby synchronization device are realized. The present application can fundamentally solve the problem of restarting the closing of the standby synchronization device when the breaker needs to trip under the condition of having been closed, and further protect the safe and stable operation of the generator-transformer group grid-connected system.
Claims
1. An optimized coordination protection method based on dual-set synchronization devices, characterized in that, Includes the following steps: Set A is the main synchronizing device, and set B is the backup synchronizing device. When the main synchronizing device detects that the synchronization conditions on both sides of the circuit breaker have been met, it issues a closing command. When the main synchronizing device successfully issues the closing command, the circuit breaker closes. When the main synchronizing device fails to issue the closing command, the backup synchronizing device is activated. The backup synchronizing device issues a closing command after determining that the synchronization conditions on both sides of the circuit breaker have been met. When the backup synchronizing device successfully issues the closing command, the circuit breaker closes. When the backup synchronizing device fails to issue the closing command, the backup synchronizing device enters the device lockout state. After a reset or delay, it re-enters the initial standby state. When the circuit breaker closes successfully, the circuit breaker auxiliary contacts close; when the circuit breaker fails to close, the main synchronizing device cannot detect the circuit breaker auxiliary contact closing signal, so it enters the device lockout state, and then after a reset or delay time, it re-enters the initial standby state. After the circuit breaker auxiliary contact is closed, if the main synchronizing device does not detect the signal of the auxiliary contact being closed, it enters the device lockout state. After a reset or delay, it re-enters the initial standby state. When the primary synchronizing device acquires the circuit breaker auxiliary contact closing signal, it sends a closing signal to the backup synchronizing device; when the backup synchronizing device receives the closing signal, it issues a blocking command and receives a blocking signal, then performs self-blocking and enters the device blocking state. When an abnormality occurs after the circuit breaker auxiliary contact is closed, the protection action requires the circuit breaker to trip or there is a fault in the external equipment, and the circuit breaker trips successfully.
2. The optimized coordination protection method based on dual-set synchronization devices according to claim 1, characterized in that, When the circuit breaker fails to close, the main synchronizing device cannot detect the circuit breaker auxiliary contact closing signal, and then displays the circuit breaker abnormal lockout, enters the device lockout state, and then, after a reset or delay time, re-enters the initial standby state.
3. The optimized coordination protection method based on dual synchronization devices according to claim 1, characterized in that, After the circuit breaker auxiliary contact is closed, if the main synchronizing device does not detect the signal of the auxiliary contact being closed, it will prompt an alarm indicating abnormal circuit breaker locking and enter the device locking state. After a reset or delay, it will re-enter the initial standby state.
4. The optimized coordination protection method based on dual synchronization devices according to claim 1, characterized in that, The external device malfunctioned by having no pressure on one side.
5. The optimized coordination protection method based on dual-set synchronization devices according to claim 1, characterized in that, When the circuit breaker fails to close, if the main synchronizing device does not detect the circuit breaker auxiliary contact closing signal within a preset time, it will enter the device lockout state. After a reset or delay, it will re-enter the initial standby state.