DC conversion switch and DC bypass switch anti-trip secondary circuit and control method
By setting the anti-hop function in the open circuit, the problem that the anti-hop loop design of the DC conversion switch and bypass switch in the prior art is not suitable for the DC system, and the reclosing and locking when the conversion fails, improving the reliability and availability of the system.
Patent Information
- Application Number
- CN202310440826.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-04-23
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2043-04-23
AI Technical Summary
The anti-jump loop design of existing DC conversion switches and DC bypass switches is inconvenient compared to the DC system, resulting in failure in wiring conversion, affecting system availability and damaging equipment and system safety.
The anti-hop functions of the DC conversion switch and DC bypass switch are set in the opening circuit, and the opening circuit is cut off by the anti-hop action instead of the closing circuit, so that the gate can be reclosed and locked when the conversion fails, reducing the risk of failure and improving system reliability and availability.
It effectively solves the problem of frequent misissuance of open-opening commands caused by the sticking of the contacts of the opening circuit during the closing process of the traditional anti-jump circuit or short-connecting with the signal power supply, improves the reliability and availability of the system, and ensures the safety of the equipment and system.
Smart Images
Figure CN116404617B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an anti-trip secondary circuit and a control method of a DC conversion switch and a DC bypass switch, belonging to the technical field of converters. Background Art
[0002] DC transfer switches and DC bypass switches are one of the important equipment in the DC part of the converter station. Their main technical performance is reflected in insulation strength, breaking and conversion current capability, environmental tolerance, etc. In recent years, with the implementation of DC projects such as Yanmenguan-Huai'an, Ximeng-Taizhou, Changji-Guquan, Baihetan-Jiangsu, etc., the development and research of DC transfer switches and DC bypass switches have received more and more attention.
[0003] Conventional DC transfer switches and DC bypass switches are modified from the design of AC circuit breakers. Taking the secondary circuit of the DC transfer switch operating mechanism of the ±800kV Huai'an Converter Station put into operation in 2017 as an example (the DC bypass switch has the same principle), the anti-trip circuit of the DC transfer switch of Huai'an Converter Station is as follows: Figure 1 As shown in the figure: S4 is the remote control operation selection switch, K9 is the SF6 low density opening and closing lock auxiliary switch, K3 is the anti-trip relay, BW1 is the closing limit switch without energy storage, BG1 is the position switch, Y3 is the closing coil, R4 is the closing circuit monitoring resistor, and R11 is the protection resistor. The default state of the figure is: the switch is open, the spring is not stored, and the SF6 gas is at the rated pressure.
[0004] At present, the anti-tripping function design of DC conversion switches and DC bypass switches still follows the principles of AC systems and is designed according to the principle of fixed switches in the open state. Figure 1 In the anti-tripping circuit shown, before the DC conversion switch and DC bypass switch are closed, switch S4 is selected for remote control, S4: 1-2 is turned on, SF6 gas pressure is normal, K9: 32-31 is turned on, closing spring has stored energy, BW1: 13-14 is turned on, the switch is in the open position, BG1: 01-02 is closed, BG1: 03-04, 43-44 is opened, anti-tripping relay K3 is not energized, K3: 24-21 is opened, 12-11 is closed. When the DC conversion switch and DC bypass switch are closed, the remote control closing command is issued, the closing circuit is turned on, the closing coil Y3 is energized, and the switch is closed. After closing, the switch is in the closed position, BG1: 03-04, 43-44 are closed, the anti-tripping relay K3 is energized, K3: 24-21 is closed, 12-11 is disconnected, the closing circuit is disconnected, and K3 is self-holding, and the switch cannot continue to close.
[0005] According to the above analysis, the existing anti-trip circuit design is not adaptable to the DC system. If the switch is operated in the above manner, the following problems will occur: (1) Failure of wiring mode conversion: When converting the system wiring mode or putting the DC conversion switch and bypass switch into operation, if the closing command is frequently issued due to adhesion of the closing contacts, misoperation, short circuit with the signal power supply, etc., the anti-trip function is activated after closing, the closing circuit is disconnected, and the wiring mode switching cannot be completed correctly, which cannot meet the DC system movement mode conversion requirements; (2) Impact on the availability of the DC system: If the switch is mistakenly disconnected after closing or closed in a fault state, the DC conversion switch and bypass switch cannot continue to close after the protection action is disconnected, which obviously cannot meet the requirements of ensuring the reliability and availability of the DC system; (3) Endangering the safety of equipment and systems: The DC conversion switch is prone to conversion failure when separating large DC currents (such as neutral grounding faults). If the existing anti-trip method is used, the conversion switch will continue to arc, which cannot meet the maximum conversion current and conversion failure requirements, endangering the safety of equipment and systems, and even causing the switch to explode or the fault to expand. Summary of the invention
[0006] In order to solve the problems existing in the prior art, the present invention proposes an anti-tripping secondary circuit and control method for a DC conversion switch and a DC bypass switch, and the anti-tripping function of the DC conversion switch and the DC bypass switch is set in the opening circuit, which solves the problem of frequent erroneous issuance of opening commands due to adhesion of the opening circuit contacts or short-circuiting with the signal power supply during the closing process of the traditional anti-tripping circuit. When the switch conversion fails, it can also cooperate with the control and protection system to reconnect and lock, reducing the risk of switch failure and improving the reliability and availability of the system.
[0007] In order to solve the above technical problems, the present invention adopts the following technical means:
[0008] In the first aspect, the present invention proposes a secondary anti-tripping circuit for a DC conversion switch and a DC bypass switch, including a remote and local control operation selection switch, a closing spring non-energy storage limit switch, an opening spring non-energy storage limit switch, an SF6 low density closing and opening locking auxiliary switch, a two-way closing and opening interlocking relay and auxiliary switch, two-way anti-tripping relay and auxiliary switch, a position switch, a closing and opening coil, a closing circuit monitoring resistor, an opening circuit monitoring resistor and a protection resistor.
[0009] The remote and local control operation selection switch is respectively connected to one end of the SF6 low-density opening and closing locking auxiliary switch, an auxiliary switch of the first opening and closing interlocking relay, and the first contact of the position switch; the other end of the SF6 low-density opening and closing locking auxiliary switch is respectively connected to one end of the closing spring non-energy storage limit switch and another auxiliary switch of the first opening and closing interlocking relay, the other end of the closing spring non-energy storage limit switch is connected in sequence to the second contact of the position switch, the closing spring energy storage limit relay and the closing coil, the other auxiliary switch of the first opening and closing interlocking relay is connected in sequence to the second opening and closing interlocking relay, an auxiliary switch of the first anti-tripping relay, and the second anti-tripping relay an auxiliary switch, a limit switch with no energy storage in the opening spring, the third contact of the position switch and the opening coil; the first contact of the position switch is connected in sequence to another auxiliary switch of the first anti-tripping relay and another auxiliary switch of the second anti-tripping relay; the closing circuit monitoring resistor is connected in series with the normally open contact of the second contact of the position switch and then connected in parallel to the two ends of the normally closed contact of the second contact of the position switch; the opening circuit monitoring resistor is connected in series with the normally closed contact of the third contact of the position switch and then connected in parallel to the two ends of the normally open contact of the third contact of the position switch; the protection resistor is connected in parallel to the first anti-tripping relay and the second anti-tripping relay.
[0010] In combination with the first aspect, further, the anti-tripping secondary circuit includes a closing circuit, an opening circuit and an anti-tripping circuit.
[0011] In combination with the first aspect, further, the closing circuit includes a remote control operation selection switch, a low SF6 density closing lock auxiliary switch, a first opening and closing interlock relay, a closing spring non-energy storage limit switch, a position switch, a closing circuit monitoring resistor, a closing coil, and a closing spring energy storage limit relay; the positive potential of the power supply, the remote control operation selection switch, the low SF6 density closing lock auxiliary switch, the closing spring non-energy storage limit switch, the second contact of the position switch, the closing spring energy storage limit relay, the closing coil and the negative potential of the power supply are connected in series in sequence, the normally open contact of the second contact of the position switch is connected in series with the closing circuit monitoring resistor and then connected in parallel to the two ends of the normally closed contact of the second contact of the position switch, the closing spring energy storage limit relay is connected in parallel to the closing spring non-energy storage limit switch to the closing coil section, and the positive potential of the power supply, the remote control operation selection switch, the first opening and closing interlock relay and the negative potential of the power supply are connected in series in sequence.
[0012] In combination with the first aspect, further, the opening circuit includes a remote control operation selection switch, a SF6 low density closing lock auxiliary switch, a first opening and closing interlock relay, a second opening and closing interlock relay, a first anti-trip relay, a second anti-trip relay, an opening spring un-energy stored limit switch, a position switch, a opening circuit monitoring resistor, and an opening coil; the positive potential of the power supply, the remote control operation selection switch, the SF6 low density closing lock auxiliary switch, the first opening and closing interlock relay, the second opening and closing interlock relay, the first anti-trip relay, the second anti-trip relay, the opening spring un-energy stored limit switch, the third contact of the position switch, the opening coil, and the negative potential of the power supply are connected in series in sequence, and the normally closed contact of the third contact of the position switch is connected in series with the opening circuit monitoring resistor and then connected in parallel to the two ends of the normally open contact of the third contact of the position switch.
[0013] In combination with the first aspect, further, the anti-tripping circuit includes a remote control operation selection switch, a position switch, a first anti-tripping relay, a second anti-tripping relay, a protection resistor, and an anti-tripping auxiliary switch; the positive potential of the power supply, the remote control operation selection switch, the normally closed contact of the first contact of the position switch, the first anti-tripping relay, the second anti-tripping relay, and the negative potential of the power supply are connected in series in sequence, the protection resistor is connected in parallel to both ends of the first anti-tripping relay and the second anti-tripping relay, and the normally open contact of the anti-tripping auxiliary switch is connected in parallel with the position switch.
[0014] In combination with the first aspect, further, the default state of the anti-trip secondary circuit is: the DC conversion switch and the bypass switch are in open position, the closing spring has no energy stored, and the pressure of the SF6 gas is the rated pressure.
[0015] In combination with the first aspect, further, the anti-tripping secondary circuit sets the anti-tripping function of the DC conversion switch and the DC bypass switch in the opening circuit.
[0016] In a second aspect, the present invention proposes a control method for an anti-tripping secondary circuit of a DC conversion switch and a DC bypass switch, wherein the anti-tripping secondary circuit adopts the anti-tripping secondary circuit proposed in the first aspect.
[0017] Before the DC conversion switch and the DC bypass switch are opened, the anti-tripping secondary circuit switches the remote and local control operation selection switch to the remote control position, the SF6 gas pressure is normal, the SF6 density is low, the opening and closing lock is turned on, the opening and closing interlocking relay in the closing circuit shall not be energized, the opening and closing interlocking relay in the opening circuit is turned on, the opening spring stores energy, the opening non-energy storage limit switch in the opening circuit changes from normally open to closed, and the DC conversion switch and the DC bypass switch are in the closed position; one position switch contact in the opening circuit is closed, and the other position switch contact is disconnected, the position switch in the closing circuit is disconnected, and the anti-tripping relay contact in the opening circuit is closed.
[0018] In combination with the second aspect, further, when the DC conversion switch and the DC bypass switch are opened, the anti-trip secondary circuit obtains a remote control opening command, and turns on the opening circuit according to the remote opening command, so that the opening coil is energized to control the opening of the DC conversion switch and the DC bypass switch.
[0019] In combination with the second aspect, further, after the DC conversion switch and the DC bypass switch are opened, the anti-tripping secondary circuit is in the open position, the position switch in the anti-tripping circuit is closed, the anti-tripping relay contacts in the anti-tripping circuit are closed, the anti-tripping relay contacts in the opening circuit are disconnected, the opening coil loses power and the anti-tripping relay is self-holding, so that the DC conversion switch and the DC bypass switch cannot continue to be opened.
[0020] The following advantages can be obtained by using the above technical means:
[0021] The present invention proposes an anti-tripping secondary circuit and a control method for a DC conversion switch and a DC bypass switch. The anti-tripping function of the DC conversion switch and the DC bypass switch is designed in an opening circuit according to the principle of being fixed in a closed state. During the opening process of the DC conversion switch and the DC bypass switch, the anti-tripping secondary circuit can cut off the opening circuit through an anti-tripping action instead of the closing circuit. Therefore, when the DC conversion switch and the DC bypass switch fail to convert, the switch can be reclosed and locked, which effectively reduces the risk of switch failure, improves the reliability and availability of the system, and solves the problem of frequent erroneous issuance of opening commands and erroneous opening of the switch due to adhesion of opening circuit contacts or short circuit with a signal power supply during the closing process of traditional DC conversion switches and DC bypass switches.
[0022] The anti-trip secondary circuit of the present invention can not only ensure the closing function of the DC conversion switch and the DC bypass switch, but also cooperate with the switching of various operating modes of the system, and has higher applicability. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a structural schematic diagram of the anti-tripping circuit of the DC transfer switch of Huai'an Converter Station;
[0024] Figure 2 It is a schematic diagram of the arrangement of the DC conversion switch and the bypass switch;
[0025] Figure 3 It is a structural schematic diagram of an anti-trip secondary circuit in an embodiment of the present invention;
[0026] In the figure, 1 is the opening circuit, 2 is the closing circuit, and 3 is the anti-trip circuit. DETAILED DESCRIPTION
[0027] The technical solution of the present invention is further described below in conjunction with the accompanying drawings:
[0028] The DC transfer switch is connected in series in the main current loop, including the neutral bus switch (NBS), the neutral bus ground switch (NBGS), the metal return transfer breaker (MRTB), and the ground return transfer switch (GRTS). The DC bypass switch (BPS) is connected in parallel with the converter valve and is part of the valve group unlocking and locking sequence operation. The arrangement of the DC transfer switch and the DC bypass switch is as follows: Figure 2 shown.
[0029] The most important performance indicator of DC conversion switches and DC bypass switches is to ensure that the DC power transmission is not interrupted when the DC operation mode is converted. Therefore, the maximum conversion current capacity of the DC conversion switch should be higher than the possible maximum operating DC current passing through the equipment at the beginning of the conversion operation. If the capacity is not met, it is necessary to add protection control in the control system, and the control system must reduce the DC current to the range that the DC switch can withstand before the conversion operation begins.
[0030] The main functions of the DC conversion switch and the DC bypass switch are to maintain the reliability and availability of the DC system through the closing action and to protect related equipment. In order to prevent the frequent mis-issuance of the opening command and the switch from opening incorrectly due to the adhesion of the opening circuit contacts or the short circuit with the signal power supply during the closing process, the present invention improves the anti-tripping function of the DC conversion switch and the DC bypass switch.
[0031] Different from the anti-tripping circuit of the traditional DC conversion switch and the DC bypass switch which is designed according to the principle of fixing the switch in the open state, the present invention designs the anti-tripping function of the DC conversion switch and the DC bypass switch in the open circuit according to the principle of fixing them in the closed state, and proposes an anti-tripping secondary circuit of the DC conversion switch and the DC bypass switch. The whole circuit includes three parts: an open circuit 1, a closed circuit 2 and an anti-tripping circuit 3.
[0032] The anti-tripping secondary circuit of the present invention mainly includes a remote and local control operation selection switch, a closing spring non-energy storage limit switch, an opening spring non-energy storage limit switch, a SF6 low density opening and closing locking auxiliary switch, a two-way opening and closing interlocking relay and auxiliary switch, a two-way anti-tripping relay and auxiliary switch, a position switch, an opening and closing coil, a closing circuit monitoring resistor, an opening circuit monitoring resistor and a protection resistor, etc.
[0033] In the embodiment of the present invention, taking the DC conversion switch operating mechanism as an example, the anti-trip secondary circuit is as follows: Figure 3As shown, S4 is the remote control operation selection switch, K9 is the SF6 low density opening and closing lock auxiliary switch, K12 is the first opening and closing interlock relay, K13 is the second opening and closing interlock relay, K4 is the first anti-trip relay, K3 is the second anti-trip relay, BW1 is the closing spring un-energy storage limit switch, BW2 is the opening spring un-energy storage limit switch, BG1 is the position switch, Y1 is the opening coil, Y3 is the closing coil, R4 is the closing circuit monitoring resistor, R5 is the opening circuit monitoring resistor, R11 is the protection resistor, and K2.1 is the closing spring energy storage limit relay; Figure 3 The dotted lines in the figure represent different auxiliary switches of the same relay. The same relay can control multiple auxiliary switches, and these auxiliary switches can be set in different circuits. Figure 3 The dotted line in the figure may pass through multiple loops. In addition, the position switch includes multiple contacts, which appear in multiple loops. The embodiment of the present invention uses the first, second, and third contacts of the position switch to distinguish position switches in different loops.
[0034] The default state of the anti-trip secondary circuit is: the DC transfer switch and bypass switch are in open position, the closing spring has no energy stored, and the pressure of the SF6 gas is the rated pressure.
[0035] In an embodiment of the present invention, the closing circuit includes a remote and local control operation selection switch, a SF6 low density closing lockout auxiliary switch, a first opening and closing interlocking relay, a closing spring un-energy stored limit switch, a position switch, a closing circuit monitoring resistor, a closing coil, and a closing spring energy stored limit relay. The positive potential of the power supply (remote / local closing positive electricity), the remote and local control operation selection switch, the SF6 low density closing lock auxiliary switch, the closing spring un-energy storage limit switch, the second contact of the position switch, the closing spring energy storage limit relay, the closing coil, and the negative potential of the power supply (negative closing terminal) are connected in series in sequence to form a main closing circuit, wherein the normally open contact of the second contact of the position switch is connected in series with the closing circuit monitoring resistor and then connected in parallel to the two ends of the normally closed contact of the second contact of the position switch, the closing spring energy storage limit relay is connected in parallel to the closing spring un-energy storage limit switch to the closing coil section, which plays the role of cutting off the closing circuit when the closing spring is not in place, and the positive potential of the power supply, the remote and local control operation selection switch, the first opening and closing interlocking relay and the negative potential of the power supply are connected in series in sequence.
[0036] In the embodiment of the present invention, the opening circuit includes a remote control operation selection switch, a low SF6 density closing lock auxiliary switch, a first opening and closing interlock relay, a second opening and closing interlock relay, a first anti-trip relay, a second anti-trip relay, an opening spring non-energy storage limit switch, a position switch, an opening circuit monitoring resistor, and an opening coil. The positive potential of the power supply (remote / local opening positive power), the remote control operation selection switch, the low SF6 density closing lock auxiliary switch, the first opening and closing interlock relay, the second opening and closing interlock relay, the first anti-trip relay, the second anti-trip relay, the opening spring non-energy storage limit switch, the third open contact of the position switch, the opening coil, and the negative potential of the power supply (negative power end of the opening) are connected in series in sequence to form a main opening circuit, wherein the normally closed contact of the third contact of the position switch is connected in series with the opening circuit monitoring resistor and then connected in parallel to the two ends of the normally open contact of the third contact of the position switch.
[0037] In the embodiment of the present invention, the anti-tripping circuit includes a remote control operation selection switch, a position switch, a first anti-tripping relay, a second anti-tripping relay, a protection resistor, and an anti-tripping auxiliary switch. It should be noted that in the anti-tripping circuit, the first anti-tripping relay and the second anti-tripping relay have the same branch structure. Figure 3 Only the branch of the first anti-trip relay K3 is drawn, and the branch of the second anti-trip relay K4 is omitted. The positive potential of the power supply, the remote control operation selection switch, the normally closed contact of the first contact of the position switch, the first anti-trip relay, the second anti-trip relay, and the negative potential of the power supply are connected in series in sequence. The protection resistor is connected in parallel to both ends of the first anti-trip relay and the second anti-trip relay to prevent the anti-trip relay from overheating and damage. The normally open contact of the anti-trip auxiliary switch is connected in parallel with the position switch to play the role of self-maintenance of the anti-trip circuit.
[0038] The anti-tripping secondary circuit of the present invention sets the anti-tripping function of the DC conversion switch and the DC bypass switch in the opening circuit.
[0039] Based on the anti-trip secondary circuit proposed in the present invention, the present invention also proposes a control method for the anti-trip secondary circuit of a DC conversion switch and a DC bypass switch, which specifically includes:
[0040] Before the DC conversion switch and the DC bypass switch are opened, the anti-trip secondary circuit switches the remote and local control operation selection switch to the remote control position, the SF6 gas pressure is normal, the SF6 density is low, the opening and closing lock is turned on, the opening and closing interlock relay in the closing circuit shall not be energized, the opening and closing interlock relay in the opening circuit is turned on, the opening spring stores energy, the opening non-energy storage limit switch in the opening circuit changes from normally open to closed, and the DC conversion switch and the DC bypass switch are in the closed position; one position switch contact in the opening circuit is closed, and the other position switch contact is disconnected, the position switch in the closing circuit is disconnected, and the anti-trip relay contact in the opening circuit is closed.
[0041] When the DC conversion switch and the DC bypass switch are opened, a remote opening command is obtained, and the opening circuit is turned on according to the remote opening command, and the opening coil is energized to control the opening of the DC conversion switch and the DC bypass switch.
[0042] After the DC conversion switch and the DC bypass switch are opened, the DC conversion switch and the DC bypass switch are in the open position, the position switch in the anti-tripping circuit is closed, the anti-tripping relay contacts in the anti-tripping circuit are closed, the anti-tripping relay contacts in the opening circuit are disconnected, the opening coil loses power and the anti-tripping relay is self-holding, so that the DC conversion switch and the DC bypass switch cannot continue to be opened.
[0043] Combined with Figure 3 The working principle of the anti-trip secondary circuit of the present invention is further explained:
[0044] Before the DC conversion switch and DC bypass switch are opened, the remote and local control operation selection switch is switched to the remote control position, the remote and local control operation selection switch is located in the opening circuit. Contact S4:7-8 is turned on, the SF6 gas pressure is normal, the SF6 density is low, and the opening and closing lock contact K9:12-11 in the opening circuit is turned on. At this time, the first and second opening and closing interlock relays K12 and K13 in the closing circuit shall not be energized, the first and second opening and closing interlock relay contacts K12:12-11 and K13:12-11 in the opening circuit are turned on, the opening spring stores energy, and the opening non-energy storage limit switch BW2:53-54 in the opening circuit changes from normally open to closed, and the DC conversion switch and DC bypass switch are in the closed position. One position switch contact BG1:13-14 in the opening circuit is closed, the other position switch contact BG1:11-12 is disconnected, the position switch contact BG1:41-42 in the closing circuit is disconnected, the first and second anti-tripping relays K3 and K4 in the opening circuit are not energized, and the anti-tripping relay contacts K3:11-12 and K4:31-32 are closed.
[0045] When the DC conversion switch and the DC bypass switch are opened, the remote control opening command is issued, the opening circuit is connected, the opening coil Y1 is energized, and the DC conversion switch and the DC bypass switch are opened.
[0046] After the DC conversion switch and the DC bypass switch are opened, the switch is in the open position, the position switch BG1:41-42 in the anti-tripping circuit is closed, the first and second anti-tripping relays K3 and K4 are energized, the anti-tripping relay contact K3:24-21 in the anti-tripping circuit is closed, the anti-tripping relay contact K3:12-11 in the opening circuit is disconnected, the opening coil Y1 loses power, and the anti-tripping relay is self-holding. The DC conversion switch and the DC bypass switch cannot continue to be opened.
[0047] The anti-trip secondary circuit of the present invention designs the anti-trip function of the DC conversion switch and the DC bypass switch in the opening circuit according to the principle of fixing them in the closing state. When the DC conversion switch and the DC bypass switch fail to convert, the switches can be reclosed and locked, which solves the problems existing in the anti-trip method in the prior art. The specific advantages are as follows: (1) When converting the system wiring method or putting the DC conversion switch and the bypass switch into operation, in the case of frequent closing commands due to closing contact adhesion, misoperation, short circuit with the signal power supply, etc., the anti-trip function is activated after closing, the opening circuit is disconnected, and the closing circuit is not affected. The DC conversion switch and the DC bypass switch can be reclosed and locked, thereby The DC conversion switch can be switched to the bypass switch by correct action, meeting the requirements for DC system motion mode conversion; (2) If the switch is mistakenly opened or closed in a faulty state after closing, the DC conversion switch and bypass switch can continue to be closed after the protection action opens, effectively reducing the risk of switch failure and improving the reliability and availability of the system; (3) The DC conversion switch is prone to conversion failure when separating large DC currents (such as neutral grounding faults). The anti-trip secondary circuit of the present invention can be reclosed and locked after the conversion fails, thereby avoiding continuous arcing of the conversion switch, thereby meeting the maximum conversion current and conversion failure requirements and improving the safety of the equipment and system.
[0048] In the description of the present invention, it should be noted that the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or sequence.
[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A secondary circuit for preventing tripping of a DC transfer switch and a DC bypass switch, comprising a remote and local control operation selection switch, a SF6 density low opening and closing locking auxiliary switch, a closing spring un-energy storage limit switch, a position switch, a closing coil, a closing circuit monitoring resistor and a protective resistor, characterized in that: The anti-trip secondary circuit also includes a trip spring un-energy-storage limit switch, two-way trip interlock relays and auxiliary switches, two-way anti-trip relays and auxiliary switches, a trip coil and a trip circuit monitoring resistor; The remote and local control operation selection switch is respectively connected to one end of the SF6 low-density opening and closing locking auxiliary switch, an auxiliary switch of the first opening and closing interlocking relay, and the first contact of the position switch; the other end of the SF6 low-density opening and closing locking auxiliary switch is respectively connected to one end of the closing spring non-energy storage limit switch and another auxiliary switch of the first opening and closing interlocking relay, the other end of the closing spring non-energy storage limit switch is connected in sequence to the second contact of the position switch, the closing spring energy storage limit relay and the closing coil, the other auxiliary switch of the first opening and closing interlocking relay is connected in sequence to the second opening and closing interlocking relay, an auxiliary switch of the first anti-tripping relay, and the second anti-tripping relay An auxiliary switch, a limit switch for the opening spring without energy storage, the third contact of the position switch and the opening coil; the first contact of the position switch is connected to another auxiliary switch of the first anti-trip relay and another auxiliary switch of the second anti-trip relay in sequence; the closing circuit monitoring resistor is connected in series with the normally open contact of the second contact of the position switch and then connected in parallel to the two ends of the normally closed contact of the second contact of the position switch; the opening circuit monitoring resistor is connected in series with the normally closed contact of the third contact of the position switch and then connected in parallel to the two ends of the normally open contact of the third contact of the position switch; the protection resistor is connected in parallel to the first anti-trip relay and the second anti-trip relay; The anti-trip secondary circuit includes a closing circuit, an opening circuit and an anti-trip circuit; The opening circuit includes a remote control operation selection switch, a SF6 low density closing lock auxiliary switch, a first opening and closing interlock relay, a second opening and closing interlock relay, a first anti-trip relay, a second anti-trip relay, an opening spring un-energy storage limit switch, a position switch, an opening circuit monitoring resistor, and an opening coil, which are sequentially connected in series; the normally closed contact of the third contact of the position switch is connected in series with the opening circuit monitoring resistor and then connected in parallel to the two ends of the normally open contact of the third contact of the position switch; The anti-tripping circuit includes a remote control operation selection switch, a position switch, a first anti-tripping relay, a second anti-tripping relay, a protection resistor, and an anti-tripping auxiliary switch; the positive potential of the power supply, the remote control operation selection switch, the normally closed contact of the first contact of the position switch, the first anti-tripping relay, the second anti-tripping relay, and the negative potential of the power supply are sequentially connected in series, the protection resistor is connected in parallel to both ends of the first anti-tripping relay and the second anti-tripping relay, and the normally open contact of the anti-tripping auxiliary switch is connected in parallel with the position switch; The anti-tripping secondary circuit sets the anti-tripping function of the DC conversion switch and the DC bypass switch in the opening circuit.
2. The anti-trip secondary circuit of a DC conversion switch and a DC bypass switch according to claim 1, characterized in that: The closing circuit includes a remote control operation selection switch, a low SF6 density closing lock auxiliary switch, a first opening and closing interlocking relay, a closing spring non-energy storage limit switch, a position switch, a closing circuit monitoring resistor, a closing coil and a closing spring energy storage limit relay; the positive potential of the power supply, the remote control operation selection switch, the low SF6 density closing lock auxiliary switch, the closing spring non-energy storage limit switch, the second contact of the position switch, the closing spring energy storage limit relay, the closing coil and the negative potential of the power supply are connected in series in sequence, the normally open contact of the second contact of the position switch is connected in series with the closing circuit monitoring resistor and then connected in parallel to the two ends of the normally closed contact of the second contact of the position switch, the closing spring energy storage limit relay is connected in parallel to the closing spring non-energy storage limit switch to the closing coil section, and the positive potential of the power supply, the remote control operation selection switch, the first opening and closing interlocking relay and the negative potential of the power supply are connected in series in sequence.
3. The anti-trip secondary circuit of a DC conversion switch and a DC bypass switch according to claim 1, characterized in that: The default state of the anti-trip secondary circuit is: the DC conversion switch and the bypass switch are in open position, the closing spring has no energy stored, and the pressure of the SF6 gas is the rated pressure.
4. A control method for the anti-trip secondary circuit of a DC conversion switch and a DC bypass switch, characterized in that: The anti-trip secondary circuit adopts the anti-trip secondary circuit as claimed in any one of claims 1 to 3; Before the DC conversion switch and the DC bypass switch are opened, the anti-trip secondary circuit switches the remote and local control operation selection switch to the remote control position, the SF6 gas pressure is normal, the SF6 density is low, the opening and closing lock is turned on, the opening and closing interlock relay in the closing circuit is not energized, the opening and closing interlock relay in the opening circuit is turned on, the opening spring stores energy, the opening non-energy storage limit switch in the opening circuit changes from normally open to closed, and the DC conversion switch and the DC bypass switch are in the closed position; one position switch contact in the opening circuit is closed, and the other position switch contact is disconnected, the position switch in the closing circuit is disconnected, and the anti-trip relay contact in the opening circuit is closed.
5. The control method of the anti-trip secondary circuit of a DC conversion switch and a DC bypass switch according to claim 4 is characterized in that: When the DC conversion switch and the DC bypass switch are opened, the anti-trip secondary circuit obtains a remote control opening command, conducts the opening circuit according to the remote opening command, and the opening coil is energized to control the opening of the DC conversion switch and the DC bypass switch.
6. The control method of the anti-trip secondary circuit of a DC conversion switch and a DC bypass switch according to claim 4, characterized in that: After the DC conversion switch and the DC bypass switch are opened, the anti-tripping secondary circuit is in the open position, the position switch in the anti-tripping circuit is closed, the anti-tripping relay contacts in the anti-tripping circuit are closed, the anti-tripping relay contacts in the opening circuit are disconnected, the opening coil loses power and the anti-tripping relay is self-holding, so that the DC conversion switch and the DC bypass switch cannot continue to be opened.
Citation Information
Patent Citations
Electronic switch operation anti-jumping circuit
CN101807776A
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