Vacuum on-load tap-changer circuit
By connecting a vacuum circuit breaker in parallel across the reactor and controlling the sequence of operation of the switch and circuit breaker, combined with current transformer detection, the energy loss and arcing problems of traditional reactor-type vacuum on-load tap changer circuits are solved, achieving more efficient and safer circuit switching.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI HUAMING POWER EQUIP CO LTD
- Filing Date
- 2025-04-03
- Publication Date
- 2026-04-10
AI Technical Summary
Traditional reactor-type vacuum on-load tap changer circuits suffer from energy loss in non-switching states and are prone to arcing during switching, affecting equipment safety and reliability.
A first vacuum circuit breaker and a second vacuum circuit breaker are connected in parallel across the two ends of the reactor. The reactor is short-circuited in the non-switching state. During the switching process, the operation sequence of the switches and circuit breakers is precisely controlled, and the circuit current is detected by the current transformer to ensure the safe transfer of the current path and the effective connection and short circuit of the reactor.
It effectively reduces energy loss in non-switching states, improves equipment safety and reliability, ensures the stability and safety of the switching process, and extends equipment lifespan.
Smart Images
Figure CN224110116U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of vacuum on-load tap changers, and in particular to a vacuum on-load tap changer circuit. BACKGROUND
[0002] The reactive vacuum on-load tap changer circuit is widely used in power systems to adjust the different tap positions of transformer output power. With the continuous development and technological progress of power systems, this circuit plays an important role in improving power supply reliability and flexibility.
[0003] The traditional reactive vacuum on-load tap changer circuit, with reference to Figure 1 , includes reactors L1, L2, a general vacuum circuit breaker VS, switches P1, P2, P3 and P4. The fixed contact of switch P4 is electrically connected to one end of reactor L1, and the other end of reactor L1 is electrically connected to one end of general vacuum circuit breaker VS. The other end of general vacuum circuit breaker VS is electrically connected to one end of reactor L2, and the other end of reactor L2 is electrically connected to the fixed contact of switch P1. The movable contacts of switches P1 and P4 are used to electrically connect with different contacts of transformer coil winding. One end of switch P3 is electrically connected to the connection point between reactor L1 and general vacuum circuit breaker VS, and the other end of switch P3 is electrically connected to the connection point between reactor L2 and general vacuum circuit breaker VS through switch P2. The connection point of switch P2 and switch P3 is set as output end P. By setting reactors L1 and L2, the inrush current during switching is limited, thereby protecting the equipment and ensuring safe operation.
[0004] Then, since the reactors are directly connected in the circuit, the reactors will generate certain energy consumption even in the non-switching state. CONTENT OF THE INVENTION
[0005] In order to reduce the energy loss in the non-switching state, the present application provides a vacuum on-load tap changer circuit.
[0006] The vacuum on-load tap changer circuit provided by the present application adopts the following technical solution:
[0007] The application discloses a kind of vacuum load tap changer circuits, including reactor L1, reactor L2, total vacuum circuit breaker VS, switch P1, switch P2, switch P3 and switch P4, it further includes first vacuum circuit breaker VS1 and second vacuum circuit breaker VS2, the first vacuum circuit breaker VS1 is connected in parallel at the two ends of reactor L1, the second vacuum circuit breaker VS2 is connected in parallel at the two ends of reactor L2;In non-switching state, the first vacuum circuit breaker VS1 and second vacuum circuit breaker VS2 are in closed state;During switching process, the first vacuum circuit breaker VS1 and second vacuum circuit breaker VS2 are in open state.
[0008] By adopting the above technical scheme, in non-switching state, the first vacuum circuit breaker VS1 and second vacuum circuit breaker VS2 are closed, reactor L1 and reactor L2 are short-circuited, unnecessary energy consumption of reactor is avoided, and stable operation of circuit in initial state is ensured;During switching process, the first vacuum circuit breaker VS1 and second vacuum circuit breaker VS2 are opened, reactor L1 and reactor L2 are connected in circuit, and current limiting effect can be normally played.
[0009] Preferably, the total vacuum circuit breaker VS is opened before the movable contact of the switch P4 or the switch P1 is switched.
[0010] By adopting the above technical scheme, the total vacuum circuit breaker VS is opened before the movable contact of the switch P4 or the switch P1 is switched, so that no current passes through the switch contact during switching process, arc generation is avoided, and safety and reliability of switching are improved.
[0011] Preferably, the current transformer CT is further included, the primary side of the current transformer CT is electrically connected between the total vacuum circuit breaker VS and the reactor L2, and the secondary side of the current transformer CT is electrically connected with external measuring instrument;During switching process, the current transformer CT is opened after the total vacuum circuit breaker VS is opened.
[0012] By adopting the above technical scheme, the state of the total vacuum circuit breaker VS is detected by the current transformer CT, successful opening of the total vacuum circuit breaker VS is ensured, current residue caused by misoperation is avoided, and safety of system and accuracy of switching operation are improved.
[0013] Preferably, the current transformer CT is closed after the movable contact of the switch P4 or the switch P1 is switched.
[0014] By adopting the above technical scheme, the current transformer CT is closed after the movable contact of the switch P4 or the switch P1 is switched, unnecessary energy consumption caused by long-time work of the current transformer CT is avoided, and stable operation of system after switching is ensured.
[0015] As preferred, the total vacuum circuit breaker VS is closed before the opening of the switches P2 and P3.
[0016] By adopting the above technical solution, the total vacuum circuit breaker VS is closed before the opening of the switches P2 and P3, ensuring the existence of a current path in the circuit and avoiding the generation of arc when the switches are opened, thus protecting the safety of the switch contacts and the circuit.
[0017] As preferred, the switch P3 is opened before the movement of the movable contact of the switch P4; and the switch P2 is opened before the movement of the movable contact of the switch P1.
[0018] By adopting the above technical solution, the switch P3 or P2 is opened before the movement of the movable contact of the switch P4 or P1, ensuring the clarity and safety of the current path during switching and avoiding the generation of arc or misoperation due to multi-path current, thus improving the reliability and safety of switching.
[0019] In summary, the present application has at least one of the following beneficial technical effects:
[0020] 1. By connecting the first vacuum circuit breaker VS1 and the second vacuum circuit breaker VS2 in parallel across the two reactors L1 and L2, the reactors can be short-circuited in a non-switching working state, effectively avoiding the generation of energy consumption by the reactors, reducing the energy loss of the system, and improving the energy efficiency.
[0021] 2. During switching, the action sequence of each switch and vacuum circuit breaker is reasonably controlled to ensure the existence of current in the circuit without the generation of arc, thus ensuring the safe operation of the equipment and prolonging the service life.
[0022] 3. The current transformer CT monitors the current in the circuit, which can confirm whether the vacuum circuit breaker is successfully opened at the key node, thus enhancing the reliability and stability of the system. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 is a circuit diagram of the prior art;
[0024] Figure 2 is a circuit diagram of the initial state of the embodiment of the present application;
[0025] Figure 3 is a circuit diagram of the first stage of the embodiment of the present application;
[0026] Figure 4 is a circuit diagram of the second stage of the embodiment of the present application after the opening of the total vacuum circuit breaker VS;
[0027] Figure 5 is a circuit diagram of the second stage of the embodiment of the present application after the opening of the current transformer CT;
[0028] Figure 6 is the circuit diagram after the movable contact of switch P4 is switched under the second stage of the embodiment of the present application;
[0029] Figure 7 is the circuit diagram after the current transformer CT is closed under the second stage of the embodiment of the present application;
[0030] Figure 8 is the circuit diagram after the general vacuum circuit breaker VS is closed under the third stage of the embodiment of the present application;
[0031] Figure 9 is the circuit diagram after the switch P3 is closed under the third stage of the embodiment of the present application;
[0032] Figure 10 is the circuit diagram after the current transformer CT is opened under the third stage of the embodiment of the present application;
[0033] Figure 11 is the circuit diagram after the current transformer CT is closed under the third stage of the embodiment of the present application;
[0034] Figure 12 is the circuit diagram under the fourth stage of the embodiment of the present application;
[0035] Figure 13 is the circuit diagram after the general vacuum circuit breaker VS is opened under the fifth stage of the embodiment of the present application;
[0036] Figure 14 is the circuit diagram after the current transformer CT is opened under the fifth stage of the embodiment of the present application;
[0037] Figure 15 is the circuit diagram after the movable contact of switch P1 is switched under the fifth stage of the embodiment of the present application;
[0038] Figure 16 is the circuit diagram after the current transformer CT is closed under the fifth stage of the embodiment of the present application;
[0039] Figure 17 is the circuit diagram after the general vacuum circuit breaker VS is closed under the sixth stage of the embodiment of the present application;
[0040] Figure 18 is the circuit diagram after the switch P2 is closed under the sixth stage of the embodiment of the present application;
[0041] Figure 19 is the circuit diagram after the gear switching is completed. DETAILED DESCRIPTION
[0042] The following will be described in detail with reference to the accompanying drawings. Figures 2-19 The present application will be further described in detail.
[0043] The embodiment of the application discloses a vacuum on-load tap changer circuit.
[0044] With reference to Figure 2 A vacuum on-load tap changer circuit is based on a transformer coil winding, the transformer coil winding is provided with a contact 1, a contact 2 and a contact 3, and further comprises an electric reactor L1, an electric reactor L2, a general vacuum circuit breaker VS, a first vacuum circuit breaker VS1, a second vacuum circuit breaker VS2, a current transformer CT, a switch P1, a switch P2, a switch P3 and a switch P4.
[0045] A fixed contact of the switch P4 is electrically connected to one end of the electric reactor L1, and the other end of the electric reactor L1 is electrically connected to one end of the general vacuum circuit breaker VS. The other end of the general vacuum circuit breaker VS is electrically connected to one end of the electric reactor L2, and the other end of the electric reactor L2 is electrically connected to a fixed contact of the switch P1. One end of the switch P3 is electrically connected to a connection point between the electric reactor L1 and the general vacuum circuit breaker VS, and the other end of the switch P3 is electrically connected to a connection point between the electric reactor L2 and the general vacuum circuit breaker VS through the switch P2, and the connection point between the switch P2 and the switch P3 is set as an output end P. The first vacuum circuit breaker VS1 is connected in parallel across the electric reactor L1, and the second vacuum circuit breaker VS2 is connected in parallel across the electric reactor L2. A primary side of the current transformer CT is electrically connected between the general vacuum circuit breaker VS and the electric reactor L2, and a secondary side of the current transformer CT is electrically connected with an external measuring instrument.
[0046] With reference to Figure 2 In an initial state, the movable contacts of the switch P4 and the switch P1 are both electrically connected to the contact 1, the switch P2 and the switch P3 are in a closed state, and the general vacuum circuit breaker VS, the first vacuum circuit breaker VS1, the second vacuum circuit breaker VS2 and the current transformer CT are all in a closed state. At this time, the electric reactor L1 and the electric reactor L2 are short-circuited, so that energy consumption of the electric reactor L1 and the electric reactor L2 can be avoided.
[0047] In a switching process, with reference to Figure 3 In a first stage, the first vacuum circuit breaker VS1 and the second vacuum circuit breaker VS2 are disconnected, at this time, the electric reactor L1 and the electric reactor L2 are connected to a line, and the circuit is protected; meanwhile, the switch P3 is disconnected, and since the general vacuum circuit breaker VS is in a closed state, current still exists in the circuit, and the disconnection of the switch P3 will not cause an arc.
[0048] With reference to Figure 4 In a second stage, the first vacuum circuit breaker VS1, the second vacuum circuit breaker VS2 and the switch P3 remain disconnected, and the general vacuum circuit breaker VS is further disconnected, so that no current passes through the switch P4. This process ensures safe transfer of a current path in the switching process, and avoids arc damage caused by sudden current interruption.
[0049] Reference Figure 4 and Figure 5 After the general vacuum circuit breaker VS is opened, the current transformer CT is opened, and the primary side of the current transformer CT is detected by an external measuring instrument to determine whether there is current. If no current is detected, it can be ensured that the general vacuum circuit breaker VS has been successfully opened. By setting the current transformer CT, it can be effectively verified whether the switching operation of the general vacuum circuit breaker VS is successful, thereby improving the reliability and safety of the system. In this process, the movable contact of the switch P1 is electrically connected to the contact 2, and the current transformer CT is still working to ensure that no current passes through. Figure 6 After the movable contact of the switch P4 is switched, the current transformer CT is closed. Figure 7 Reference
[0050] In the third stage, the first vacuum circuit breaker VS1, the second vacuum circuit breaker VS2, and the switch P3 remain open, and the general vacuum circuit breaker VS is closed again to ensure that the discharge phenomenon that may occur after power is turned on occurs in the vacuum bubble. Then, the switch P3 is closed. The current transformer CT is opened to detect the current and ensure that there is no current. The current transformer CT is closed again. Figure 8 Figure 9 Figure 10 Figure 11
[0051] Reference Figure 12 In the fourth stage, the first vacuum circuit breaker VS1 and the second vacuum circuit breaker VS2 remain open, and the switch P2 is opened. Since the general vacuum circuit breaker VS is in a closed state, there is still current in the circuit, and the opening of the switch P2 will not produce an arc.
[0052] Reference Figure 13 In the fifth stage, the first vacuum circuit breaker VS1, the second vacuum circuit breaker VS2, and the switch P2 remain open, and the general vacuum circuit breaker VS is opened again to make the switch P1 have no current passing through. The current transformer CT is opened again after the general vacuum circuit breaker VS is opened, and the primary side of the current transformer CT is detected by an external measuring instrument to determine whether there is current. If no current is detected, it can be ensured that the general vacuum circuit breaker VS is opened. Figure 13 and Figure 14 The movable contact of the switch P1 is electrically connected to the contact 2, and the current transformer CT is still working to ensure that no current passes through. Figure 15 After the movable contact of the switch P1 is switched, the current transformer CT is closed. Figure 16
[0053] Reference Figure 17 , the sixth stage, the first vacuum breaker VS1, the second vacuum breaker VS2 and the switch P3 remain open, and the total vacuum breaker VS is closed again to ensure that the discharge phenomenon that may occur after the connection is made occurs in the vacuum bulb. Then, the switch P2 is closed. Figure 18
[0054] Referring to Figure 19 After the gear switching is completed, the first vacuum breaker VS1 and the second vacuum breaker VS2 are opened, at which time the reactor L1 and the reactor L2 are short-circuited, so that the energy consumption of the reactor L1 and the reactor L2 can be avoided.
[0055] The implementation principle of the vacuum on-load tap changer circuit according to the embodiment of the present application is as follows: by precisely controlling the states of the first vacuum breaker VS1, the second vacuum breaker VS2 and the total vacuum breaker VS, in combination with the detection function of the current transformer CT, the safe transfer of the current path and the effective connection and short-circuit of the reactor L1 and the reactor L2 are realized. In the switching process, the first vacuum breaker VS1 and the second vacuum breaker VS2 are opened, and the reactor L1 and the reactor L2 are connected to the line to protect the circuit; and in the initial state or after the switching is completed, the first vacuum breaker VS1 and the second vacuum breaker VS2 are closed to short-circuit the reactor L1 and the reactor L2 to avoid energy consumption. By the stage-by-stage operation and the use of the total vacuum breaker VS, it is ensured that the arc occurs in the vacuum bulb to prevent the arc damage, and the current transformer CT detects the current state in real time to verify the success of the operation, so that the reliability and safety of the system are improved, and the energy consumption is effectively reduced.
[0056] The above are the preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: any equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.
Claims
1. A vacuum on-load tap changer circuit comprising a reactor LI, a reactor L2, a total vacuum circuit breaker VS, a switch PI, a switch P2, a switch P3 and a switch P4, characterized in that: Further comprising a first vacuum circuit breaker VS1 and a second vacuum circuit breaker VS2, the first vacuum circuit breaker VS1 is connected in parallel across the reactor L1, the second vacuum circuit breaker VS2 is connected in parallel across the reactor L2; in the non-switching state, the first vacuum circuit breaker VS1 and the second vacuum circuit breaker VS2 are both in the closed state; in the switching process, the first vacuum circuit breaker VS1 and the second vacuum circuit breaker VS2 are both in the open state.
2. A vacuum on-load tap changer circuit according to claim 1, characterized in that: Before the moving of the active contact of the switch P4 or the switch P1, the total vacuum circuit breaker VS is opened.
3. A vacuum on-load tap changer circuit according to claim 2, characterized in that: Further comprising a current transformer CT, the primary side of the current transformer CT is electrically connected between the total vacuum circuit breaker VS and the reactor L2, the secondary side of the current transformer CT is electrically connected with external measuring instruments; in the switching process, when the total vacuum circuit breaker VS is opened, the current transformer CT is opened.
4. A vacuum on-load tap changer circuit according to claim 3, characterized in that: After the moving of the active contact of the switch P4 or the switch P1, the current transformer CT is closed.
5. A vacuum on-load tap changer circuit according to claim 1, characterized in that: Before the opening of the switch P2 and the switch P3, the total vacuum circuit breaker VS is closed.
6. A vacuum on-load tap changer circuit according to claim 1, characterized in that: Before the moving of the active contact of the switch P4, the switch P3 is opened; before the moving of the active contact of the switch P1, the switch P2 is opened.