Synchronous blocking control circuit and protection method for controlling synchronous blocking relay
By using an aviation plug in series with the secondary circuit of the bus voltage transformer in the simultaneous locking control circuit, dynamic control and physical isolation of the bus secondary voltage is achieved, the problem of secondary voltage interference in the equipment is solved, and the reliability and safety of the system are improved.
Patent Information
- Application Number
- CN202411743322.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-03-28
AI Technical Summary
When the existing concurrent lock-up control system is shut down or cold standby, the secondary voltage may enter the relay circuit through an unexpected path, resulting in malfunction or failure of the protection function, and lack of effective electrical isolation measures, which reduces the reliability and safety of the system.
A simultaneous locking control circuit is designed, and the secondary circuit of the bus voltage transformer is connected in series with the aviation plug to achieve dynamic control and physical isolation of the bus secondary voltage. The aviation plug is closed or disconnected when the working switch is closed, ensuring that the bus secondary voltage enters the circuit of the locking relay during the same period in the working state.
It effectively solves the interference problem of induction voltage inversion on the secondary circuit of electrical equipment, ensures high-precision judgment of system voltage conditions by the locking relay at the same time, and improves the safety and reliability of the system.
Smart Images
Figure CN119726596A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of synchronous locking control circuits, in particular to a synchronous locking control circuit and a protection method for controlling a synchronous locking relay. Background Art
[0002] Synchronous blocking technology is widely used in power systems to ensure the safety of generator set grid connection, bus switching and high-voltage switch operation. The synchronous blocking relay compares the amplitude, phase and frequency of the voltage to be connected and the operating voltage to determine whether the two meet the synchronization conditions, thereby controlling the closing operation of the switch.
[0003] The existing synchronous interlocking control system is usually directly connected to the secondary voltage circuit of the operating system and the system to be connected. When the equipment is in shutdown or cold standby state, the secondary voltage may enter the relay circuit through an unexpected path, causing the relay to malfunction or the protection function to fail. In addition, some control schemes lack effective electrical isolation measures, so that the equipment may still be disturbed by the bus secondary voltage when it is not working, reducing the reliability and safety of the system. Summary of the invention
[0004] In view of the above problems existing in the prior art, the present invention is proposed.
[0005] Therefore, the first object of the present invention is to provide a synchronous locking control circuit that can solve the problem of malfunction of the synchronous locking relay and secondary voltage interference in the shutdown state.
[0006] To solve the above technical problems, the present invention provides the following technical solutions: a synchronous locking control circuit, comprising a synchronous locking relay, whose input end is connected between the voltage of the system to be connected and the voltage of the operating system; a working switch voltage transformer, whose primary side is connected to the bus voltage, and whose secondary side is connected in series to the circuit of the synchronous locking relay through an aviation plug; the aviation plug is in a closed state when the working switch is closed, so that the bus secondary voltage can enter the circuit of the synchronous locking relay; and is in an open state when the working switch is opened, so that the bus secondary voltage cannot enter the circuit of the synchronous locking relay.
[0007] As a preferred solution of the synchronous locking control circuit of the present invention, the aviation plug adopts an anti-misinsertion design.
[0008] As a preferred solution of the synchronous locking control circuit of the present invention, the contacts of the aviation plug are of mechanical structure.
[0009] As a preferred solution of the synchronous locking control circuit of the present invention, the synchronous locking relay includes two coils with the same parameters and opposite polarities, which are respectively connected to the voltage of the system to be paralleled and the voltage of the operating system.
[0010] As a preferred solution of the synchronous locking control circuit described in the present invention, the action condition of the locking relay is that when the vector difference between the two system voltages is less than a predetermined value, its contacts are closed to allow the switch to be closed; otherwise, its contacts are disconnected to prohibit the switch from being closed.
[0011] As a preferred solution of the synchronous locking control circuit of the present invention, the primary side of the bus voltage transformer is connected to the 6kV bus.
[0012] As a preferred solution of the synchronous locking control circuit of the present invention, the aviation plug and the circuit of the synchronous locking relay are connected in series through a fuse.
[0013] As a preferred solution of the synchronous locking control circuit of the present invention, the secondary side output of the working switch voltage transformer has a voltage detection module.
[0014] As a preferred solution of the synchronous locking control circuit of the present invention, the synchronous locking relay has an adjustment module, which can dynamically adjust the voltage phase angle difference threshold that allows the switch to be closed according to the actual power grid conditions.
[0015] The second object of the present invention is to propose a protection method for controlling a synchronous locking relay, comprising the following steps: connecting the secondary output signal of the bus voltage voltage transformer to the circuit of the synchronous locking relay through the secondary auxiliary contacts of the control switch; when the unit is shut down and the working switch is disconnected, the secondary auxiliary contacts of the control switch are disconnected, and the aviation plug is unplugged, so that the bus voltage cannot enter the circuit of the synchronous locking relay; when the unit is started and the working switch is closed, the secondary auxiliary contacts of the control switch are closed, and the aviation plug is inserted, so that the bus voltage enters the circuit of the synchronous locking relay to participate in the synchronization judgment; using the state of the synchronous locking relay to determine whether the switch to be connected can be closed; in the event of a circuit fault, disconnecting the protection device through the fuse, and recording the fault information for subsequent maintenance.
[0016] The beneficial effects of the present invention are as follows: the present invention realizes dynamic control and physical isolation of the secondary voltage of the busbar by connecting the aviation plug in series with the secondary circuit of the busbar voltage transformer and combining the vector difference detection function of the synchronous locking relay, and effectively solves the interference problem of the inductive voltage backfeed on the secondary circuit of the electrical equipment. The newly added voltage detection module monitors the amplitude and phase of the secondary voltage in real time, ensuring the high-precision judgment of the synchronous conditions of the system voltage by the synchronous locking relay. At the same time, the dynamic adjustment module can flexibly adjust the voltage phase difference threshold according to the actual situation of the power grid to adapt to different operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:
[0018] Figure 1 This is the wiring diagram of the synchronous locking relay in the working switch and standby switch control circuit.
[0019] Figure 2 The present invention is the existing conventional principle wiring diagram of the synchronous locking control circuit.
[0020] Figure 3 This is the synchronous principle wiring diagram of the synchronous locking control circuit after rectification. DETAILED DESCRIPTION
[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.
[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0023] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive with other embodiments, either individually or selectively.
[0024] Example 1
[0025] Reference Figure 1 to Figure 3 , which is the first embodiment of the present invention, and this embodiment provides a synchronous locking control circuit. The synchronous locking control circuit includes a synchronous locking relay 100, whose input end is connected between the voltage of the system to be paralleled and the voltage of the operating system; a working switch voltage transformer, whose primary side is connected to the bus voltage, and whose secondary side is connected in series to the circuit of the synchronous locking relay 100 through an aviation plug 200; the aviation plug 200 is in a closed state when the working switch is closed, so that the bus secondary voltage can enter the circuit of the synchronous locking relay 100; and is in an open state when the working switch is opened, so that the bus secondary voltage cannot enter the circuit of the synchronous locking relay 100.
[0026] In this embodiment, the vector difference between the voltage of the system to be connected and the voltage of the operating system is detected by the synchronous locking relay 100 to determine whether the two systems meet the synchronization conditions. The primary side of the bus voltage transformer is connected to the 6kV bus, and the secondary side output signal is connected to the loop of the synchronous locking relay 100 through the aviation plug 200. When the working switch is closed, the aviation plug is in a closed state, and the bus secondary voltage is connected to the synchronous locking relay 100 for voltage judgment; when the working switch is disconnected, the aviation plug is disconnected to prevent the induced voltage from entering the loop. This design realizes dynamic control of bus voltage access, ensures clear switching between working state and shutdown state, and effectively improves the safety and reliability of system operation.
[0027] Example 2
[0028] Reference Figure 1 to Figure 3 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.
[0029] Specifically, the aviation plug adopts an anti-misinsertion design;
[0030] The positioning structure or coding method ensures that the device can only be closed when the connection is correct.
[0031] Specifically, the contact of the aviation plug 200 is a mechanical structure;
[0032] It can remain disconnected in the power-off state, ensuring that the busbar secondary voltage is completely isolated in the non-working state.
[0033] Specifically, the synchronous locking relay 100 includes two coils with the same parameters and opposite polarities, which are respectively connected to the waiting system voltage and the operating system voltage;
[0034] Used to detect the vector difference between two voltages and determine the state of the relay.
[0035] Specifically, the operating condition of the locking relay 100 is that when the vector difference of the two system voltages is less than a predetermined value, its contacts are closed to allow the switch to be closed; otherwise, its contacts are opened to prohibit the switch from being closed.
[0036] Specifically, the primary side of the bus voltage transformer is connected to the 6kV bus;
[0037] It is used to provide the secondary signal of bus voltage and has overload protection function to ensure the safety of the system.
[0038] Specifically, the aviation plug 200 and the circuit of the synchronous locking relay 100 are connected in series through a fuse, which is used to automatically disconnect in case of circuit failure to protect the equipment.
[0039] Specifically, the secondary side output of the working switch voltage transformer has a voltage detection module; used to monitor the amplitude and phase changes of the secondary voltage in real time;
[0040] Specifically, the synchronous locking relay 100 has a regulating module, which can dynamically adjust the voltage phase angle difference threshold that allows the switch to be closed according to the actual power grid conditions.
[0041] The aviation plug 200 adopts an anti-misinsertion design, and the positioning structure ensures the correctness of installation; its mechanical contact structure remains disconnected when the power is off, further improving the circuit safety. The two-coil design of the synchronous locking relay enables it to accurately detect the vector difference between the voltages of the two systems, ensuring the accuracy of the judgment results. The fuse is connected in series with the aviation plug 200 to protect the equipment by cutting off the circuit in case of a fault. The primary side of the voltage transformer is connected to the 6kV bus, and the anti-overload function ensures the stability of signal transmission. The voltage detection module monitors the changes in the secondary voltage in real time, and the dynamic adjustment module adjusts the phase angle difference threshold according to the power grid conditions, which improves the adaptability and operational reliability of the system.
[0042] Example 3
[0043] Reference Figure 1 to Figure 3 , which is the third embodiment of the present invention, provides a protection method for controlling a synchronous locking relay, comprising the following steps:
[0044] The secondary output signal of the bus voltage voltage transformer is connected to the circuit of the synchronous locking relay 100 through the aviation plug 200; when the unit is shut down and the working switch is disconnected, the aviation plug 200 is disconnected, so that the bus secondary voltage cannot enter the circuit of the synchronous locking relay; when the unit is started and the working switch is closed, the aviation plug 200 is closed, and the aviation plug is inserted, so that the bus voltage enters the circuit of the synchronous locking relay to participate in the synchronization judgment; the state of the synchronous locking relay 100 is used to determine whether the switch to be connected can be closed; in the event of a circuit fault, the protection device is disconnected by the fuse, and the fault information is recorded for subsequent maintenance.
[0045] This embodiment describes the implementation process of the protection method in detail. The aviation plug controls whether the bus secondary voltage enters the circuit of the synchronous locking relay to ensure that the synchronous locking relay 100 can accurately determine the synchronous condition under different conditions of the unit. When the unit is shut down, the aviation plug 200 is disconnected to achieve electrical isolation; when the unit is started, the aviation plug 200 is closed to complete the bus voltage access. When a fault occurs in the circuit, the fuse cuts off the power supply to protect related equipment, and records the fault information for subsequent maintenance reference, thereby realizing the intelligence and maintainability of the system.
[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.
Claims
1. A synchronous locking control circuit, characterized in that: include, A synchronous locking relay (100), the input end of which is connected between the voltage of the system to be paralleled and the voltage of the operating system; A working switch voltage transformer, the primary side of which is connected to the bus voltage, and the secondary side of which is connected in series to the circuit of the synchronous locking relay (100) through an aviation plug (200); The aviation plug (200) is in a closed state when the working switch is closed, so that the bus secondary voltage can enter the circuit of the synchronous locking relay (100); and is in an open state when the working switch is opened, so that the bus secondary voltage cannot enter the circuit of the synchronous locking relay (100).
2. The synchronous locking control circuit according to claim 1, characterized in that: The aviation plug (200) adopts a mis-insertion prevention design.
3. The synchronous locking control circuit according to claim 1 or 2, characterized in that: The contact of the aviation plug (200) is a mechanical structure.
4. The synchronous locking control circuit according to claim 3, characterized in that: The synchronous locking relay (100) comprises two coils with the same parameters and opposite polarities, which are respectively connected to the voltage of the waiting system and the voltage of the operating system.
5. The synchronous locking control circuit according to claim 4, characterized in that: The operating condition of the locking relay (100) is that when the vector difference of the two system voltages is less than a predetermined value, its contacts are closed to allow the switch to be closed; otherwise, its contacts are opened to prohibit the switch from being closed.
6. The synchronous locking control circuit according to claim 5, characterized in that: The primary side of the bus voltage transformer is connected to the 6kV bus.
7. The synchronous locking control circuit according to claim 6, characterized in that: The aviation plug (200) and the circuit of the synchronous locking relay (100) are connected in series via a fuse.
8. The synchronous locking control circuit according to claim 7, characterized in that: The secondary side output of the working switch voltage transformer has a voltage detection module.
9. The synchronous locking control circuit according to claim 8, characterized in that: The synchronous locking relay (100) has a regulating module capable of dynamically adjusting the voltage phase angle difference threshold for allowing the switch to be closed according to actual power grid conditions.
10. A protection method for controlling a synchronous locking relay, characterized in that: The following steps are involved: Connecting the secondary output signal of the bus voltage transformer to the circuit of the synchronous locking relay (100) through an aviation plug (200); When the unit is shut down and the working switch is disconnected, the aviation plug (200) is disconnected, so that the bus secondary voltage cannot enter the circuit of the synchronous locking relay; When the unit is started and the working switch is closed, the aviation plug (200) is closed and the aviation plug is inserted, so that the bus voltage enters the circuit of the synchronous locking relay to participate in the synchronization judgment; Using the state of the synchronous locking relay (100), it is determined whether the switch to be connected can be closed; In case of circuit fault, the protection device is disconnected by the fuse and the fault information is recorded for subsequent maintenance.